medical animation

Medical animation of nerve synapse

2008-05-12T06:56:00.000-07:00

Table of Contents; April 2004; Scientific American Magazine; by Staff Editor; 2 Page(s)

SA Perspectives: Breaking Out of Orbit; April 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Shortly after 11:30 p.m. Houston time on December 13, 1972, the commander of Apollo 17, Gene Cernan, took one final look across Mare Serenitatis, climbed into the lunar module and closed the hatch. It was the last time anyone has had his boots planted in alien soil. Since then, the human space program has been adrift. Lacking an overarching mission, astronauts putter around in orbit doing make-work.

This past January 14, President George W. Bush gave them something big to shoot for: a return to the moon by 2020 and a human mission to Mars sometime after that. His plan phases out the shuttle by 2010, replaces it by 2014 and abandons the space station in 2016. A presidential commission headed by aerospace veteran Edward C. "Pete" Aldridge, Jr., has started to flesh out the details, and NASA is already ramping up a technology development effort. Meanwhile the European Space Agency has laid out similar goals with a similar timetable and initial budget. Plenty of blanks need to be filled in, but that is natural in the early stages of a multigenerational project.

How to Contact Us and On the Web; April 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Letters to the Editors; April 2004; Scientific American Magazine; by Staff Editor; 2 Page(s)

In the December 2003 issue's cover story, "Does Race Exist?" authors Michael J. Bamshad and Steve E. Olson predicted that new genetic studies of matters related to race will lead to "a much deeper understanding of both our biological nature and our human connectedness." In the same issue, Scientific American's Board of Editors recognized 50 visionaries whose work in research, technology and policy left the world a bit better at the close of the year. While geneticists work on the microscopic explanations of our human connectedness, the particularly international character of the responses to the "Scientific American 50" was heartening macroscopic evidence of our interrelations. The letters come together on the following pages.

I was disappointed to learn from "Racing to Conclusions" [SA Perspectives] that the Food and Drug Administration is proposing that "racial" data be collected as part of clinical trials. Your article did not state strongly enough that the current racial/ethnic classifications promoted by the Census Bureau are archaic, inaccurate and confounding. Data derived from such classification are of extremely limited value, the main result being the perpetuation of outdated concepts about the human race.

50, 100 and 150 Years Ago; April 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

SEX FOR PLEASURE - "Social, political and public health leaders in many countries are now seriously concerned with the population question and are taking active steps to disseminate family planning information in an effort to bring about a better balance between resources and populations. In attempting to introduce family planning measures, however, they are confronted with a major problem: the need for a contraceptive method which is simple, practical and within economic reach of everyone."

TRITIUM - "Until less than a decade ago men did not know tritium existed. It was discovered first as a synthetic product of nuclear transformation in a reactor; then it was detected in nature. The finding of tritium in nature was not easy. The total amount on our planet is about two pounds, and most of that is in the oceans, so diluted as to be beyond detection. Why bother to hunt down this infinitesimal substance? The answer is that tritium (radiohydrogen), like radiocarbon, may be an excellent tracer for studying natural processes. With it we can date plant products, and tritium in the earth's precipitation may tell us a good deal about the great movements of air and moisture over the face of the globe. - Willard F. Libby" [Editors' note: Libby won the 1960 Nobel Prize in Chemistry for his work on carbon 14.]

Fly Me to the Moon; April 2004; Scientific American Magazine; by Mark Alpert; 2 Page(s)

When President George W. Bush declared in January that NASA would set its sights on returning astronauts to the moon by 2020, scientists quickly lined up on opposing sides. Although Bush's plan promises more funding for researchers studying the moon and Mars, other branches of space science are already feeling the pinch. The most prominent loser by far is the Hubble Space Telescope. Just two days after the president presented his initiative, NASA announced that it would cancel a shuttle flight to install new gyroscopes, batteries and scientific instruments to the Hubble. If NASA does not reverse the decision, its premier space observatory will cease operating when its current equipment fails in the next few years.

The problem arises from the Bush administration's strategy of financing the moon effort through the early retirement of the space shuttle. During the phaseout, targeted for 2010, much of the shuttle's $4-billion annual budget will be shifted toward designing a crew exploration vehicle that could take astronauts to the moon. In the meantime, shuttle missions will focus on assembling the International Space Station.

Sobering Shift; April 2004; Scientific American Magazine; by Sally Lehrman; 2 Page(s)

Since the first "alcoholism gene," dubbed DRD2, was found in 1990, researchers have hunted for DNA sequences that might predispose someone to a drinking problem. But DRD2's role in alcoholism has remained extremely controversial, and despite many efforts, no better candidates have emerged.

Many investigators are now taking a different tack. Instead of searching in families and populations of alcoholics for genes that might broadly confer a high risk for dependence, they are attempting to understand alcohol's effects and why they differ among people. In an explosion of studies, scientists have used rodents, fruit flies, zebra fish and roundworms to study characteristics such as sensitivity to intoxication and severity of withdrawal. By exploring alcohol's interaction with genes and the associated biological pathways, they hope to find clues to alcohol's addictive qualities.

Missing Movement; April 2004; Scientific American Magazine; by Wendy M. Grossman; 2 Page(s)

In mid-February the U.S. government gave up on its search for the herd mates of the first known U.S. case of bovine spongiform encephalopathy (BSE), popularly known as mad cow disease. The end of the trace-back effort, which began after the sick animal was uncovered in December 2003, means that the whereabouts and disposition of 52 of the 81 cattle that entered the country with the infected cow from Canada will remain uncertain. Of those 52, 11 were born at about the same time as the BSE cow and may have eaten the same contaminated feed that is presumed to have been the vector for the sickness.

The problem lies with the antiquated method of keeping tabs on animals - important not just for BSE but for other illnesses among livestock, such as foot-and-mouth disease, and for food poisoning resulting from Escherichia coli or Salmonella contamination. Unlike Canada, the U.K., the European Union and Australia, the U.S. does not mandate livestock tracking nationally. Moreover, there are significant regional differences in how animals are handled. Reliance on paper records contributes to slowness and inefficiency. And because only sick animals and their herd mates are followed, success in wiping out some livestock diseases (such as brucellosis) has, ironically, acted in the past few years to reduce the number of animals being tracked.

Magnetic Moods; April 2004; Scientific American Magazine; by Emily Harrison; 1 Page(s)

A 20-minute spell in an MRI tube is nobody's idea of a good time. So when several depressed patients exited a novel scanning session laughing, joking and exhibiting generally jovial behavior, researchers led by imaging physicist Michael Rohan and imaging center director Perry F. Renshaw at McLean psychiatric hospital in Belmont, Mass., quickly decided to investigate. What their preliminary study suggests is that the unique induced electrical fields associated with that particular type of magnetic resonance imaging session could improve the mood of patients with bipolar disorder.

The scan used in the study was an echo-planar magnetic resonance spectroscopic imaging (EP-MRSI) procedure, a fairly new method of MRI that McLean researchers were using to observe the effects of certain pharmaceuticals on bipolar subjects at the time of the serendipitous observation. Of the 30 individuals who received the EP-MRSI scans, 23 reported immediate mood improvement, the team says in the January issue of the American Journal of Psychiatry. The scans did not affect healthy individuals, eliminating the unsettling possibility that such electromagnetic therapy could be used to get a one-shot hit of happiness.

Shattered Glass; April 2004; Scientific American Magazine; by David Appell; 3 Page(s)

Physicists investigating heavy-particle collisions believe they are on the track of a universal form of matter, one common to very high energy particles ranging from protons to heavy nuclei such as uranium. Some think that this matter, called a color glass condensate, may explain new nuclear properties and the process of particle formation during collisions. Experimentalists have recently reported intriguing data that suggest a color glass condensate has actually formed in past work.

Particles such as protons and neutrons consist of smaller particles called quarks and gluons. Just as electrons have an electrical charge and transmit their force via photons, quarks have a "color" charge and transmit their force via gluons. But one major difference is that gluons, unlike photons, interact strongly with one another. As protons or heavy nuclei, such as gold, are accelerated to nearly the speed of light, the quarks and gluons inside flatten into a pancakelike structure, a relativistic effect called Lorentz contraction. The energy of acceleration also produces more gluons. The flattened multitude of gluons then begins to overlap, falling into the same quantum state, similar to the way atoms in a low-temperature Bose-Einstein condensate overlap and behave collectively as one gigantic atom.

Double Distress; April 2004; Scientific American Magazine; by Rebecca Renner; 1 Page(s)

Amphibians are in decline, and the causes remain controversial. Among the earliest suspected culprits were pesticides, but the role of those toxic substances is not so obvious. Only a few reports have linked amphibian declines to pesticides. And even in those few studies, the pesticide concentrations appear to be too low to kill amphibians.

But University of Pittsburgh biologist Rick A. Relyea suggests that standard toxicology may greatly underestimate the power of pesticides on frogs in the wild. In the December 2003 Ecological Applications, he shows that carbaryl, a common pesticide sold as Sevin, is much more lethal to tadpoles - up to 46 times - when the pesticide is combined with another stressor: the presence of a predator.

By the Numbers: A Surplus of Women; April 2004; Scientific American Magazine; by Rodger Doyle; 1 Page(s)

In 19th-century America, men of marriageable age outnumbered women, in part because the immigrant stream was heavily male and because many young women died in childbirth. Changes in immigration and mortality now mean that the reverse is true. In 1890 there were 107 males for every 100 females in the 20- to 44-year-old group, but in 2002 the ratio had dropped to 98 per 100.

The present imbalance has led to exaggerated reports of female marriage prospects. For example, a widely publicized report in 1986 claimed that a white college-educated woman still single at 35 had a 5 percent chance of marrying; at 40, her chances declined to 1 percent. The conclusion seemed credible because it fed the stereotype that women who have a college degree have trouble finding a husband - a notion apparently originating in the late 19th century when marriage by female college graduates was low. A far more reliable forecast, based on more sophisticated analyses, comes from two Princeton University demographers, Joshua R. Goldstein and Catherine T. Kenney, who estimate that 97 percent of white female college graduates born between 1960 and 1964 will eventually marry.

News Scan Briefs; April 2004; Scientific American Magazine; by Charles Choi, JR Minkel; 2 Page(s)

Land mines kill or injure some 26,000 people every year, and roughly 110 million remain unexploded in about 64 countries. Genetically engineered vegetation could help detect these hidden bombs. Biotechnology firm Aresa Biodetection in Copenhagen has modified the common garden weed thale cress (Arabidopsis thaliana). If their roots detect chemicals common to explosives, such as nitrogen dioxide, that leak out as mines corrode, the plants react as if it were autumn and change from green to red in three to six weeks. Aresa plans to test its plant, whose pollen has been rendered sterile, in small, restricted areas in Sri Lanka, Bosnia and other war-torn places. The hope is to clear mine-ridden land safely and cheaply so that farmers can resume cultivation. The company, which announced the plants creation on January 24, is also working on plants to detect and remove heavy metals in polluted soil.

When physicist Hans J. Herrmann of the University of Stuttgart in Germany heard a 1985 talk about tectonic plates sliding past each other with unexpectedly low friction, he began mulling over the nature of space-filling groups of ball bearings. He soon found theoretical arrays of two-dimensional disks that all turn in harmony, but a three-dimensional version proved elusive - no matter the arrangement, some balls would slip and rub, instead of turning against their neighbors. The physicist and his colleagues have now solved the problem theoretically. Imagine a sphere with six smaller spheres placed inside like the corners of a regular octahedron. The remaining space inside the big sphere can be completely filled with ever smaller spheres in a fractal pattern by a mathematical technique called inversion. Turn one sphere, and the rest turn without rubbing. A real bearing based on this model must consist of finitely many spheres, which Herrmann says would still be frictionless unless the balls were somehow forced out of place. Turn to the January 30 Physical Review Letters for the head-spinning result.

Innovations: Making Proteins without DNA; April 2004; Scientific American Magazine; by Gary Stix; 2 Page(s)

Emil Fischer experimented with making polypeptides - chains of at least three amino acids - during the opening years of the 20th century. Fischer received the Nobel Prize in 1902 for his work on the synthesis of sugars and purines. But he never reached his goal of concocting a complete protein. Nearly 90 years later chemists were not doing that much better. The only practical methods of producing synthetic polypeptides had reached about the 50amino acid mark, the size of the smallest proteins. But much of the attention had switched to recombinant-DNA methods that copied a gene and then inserted the clone into a cell that could pump out protein.

A few diehards, however, could still see the promise of synthetic chemistry. In 1989 biochemist Stephen B. H. Kent, along with colleagues from the California Institute of Technology used a synthetic process to make the HIV protease - the enzyme needed to make the virus fully functional. Then, along with collaborators from the National Cancer Institute, the team went on to determine the crystalline structure of the protein. "Some of us were too old-fashioned to stop making things by chemistry," Kent says. "We beat out people in the pharmaceutical industry who were trying to clone and express proteins."

Staking Claims: Patent Enforcement; April 2004; Scientific American Magazine; by Gary Stix; 1 Page(s)

The U.S. intellectual-property system has distinguished itself in the past several years for such gems as patents on privatizing government, a method for using a playground swing, and a computerized system that handles reservations for going to the toilet. But patenting the obvious is by no means confined to the land of reality shows and SUVs.

In recent years, Costa Rica has given new meaning to the legal term "patent enforcement." It all has to do with the country's popular canopy tours, in which visitors strapped in a harness slide along a cable between treetop platforms. For Costa Rica, decade-old canopy tours are big business, generating a reported $120 million annually. It is estimated that a quarter of the more than a million tourists who come here every year patronize one of the 80-plus tour operations.

Skeptic: Magic Water and Mencken's Maxim; April 2004; Scientific American Magazine; by Michael Shermer; 1 Page(s)

Henry Louis Mencken was a stogie-chomping, QWERTY-pounding social commentator in the first half of the 20th century who never met a man or a claim he didn't like ... to disparage, critique or parody with wit that would shame Dennis Miller back to Monday Night Football. Stupidity and quackery were favorite targets for Mencken's barbs. "Nature abhors a moron," he once quipped. "No one in this world, so far as I know ... has ever lost money by underestimating the intelligence of the great masses of the plain people," he famously noted. Some claims are so preposterous, in fact, that there is only one rejoinder: "One horselaugh is worth ten thousand syllogisms." I call this "Mencken's maxim," and I find that it is an appropriate response to preposterous claims made about magic water sold on the Web. I offer as a holotype of Mencken's maxim the following: Golden 'C' Lithium Structured Water (www.luminanti.com/goldenc.html).

This "is pure water infused with the energies of the Golden 'C' crystal, a very special and extremely rare stone mined near San Diego at the turn of the 20th century." The stone "contains more lithium than any other stone on the planet" and "emits a signature one-of-a-kind healing energy." How does the Golden 'C' water get these magical qualities? Crystal and water are placed in a ceramic container in a "dark and quiet space" for 24 hours, then the water is poured into "violet glass bottles" that "energize it." Finally, "each violet bottle is placed precisely within a special copper pyramid, specially designed to have the exact Sacred Geometry to create a Pillar of Light Jacob's Ladder vortex."

Insights: Draining the Language out of Color; April 2004; Scientific American Magazine; by Philip E. Ross; 2 Page(s)

Would a rose by any other name really smell as sweet? Do our words shape our thoughts, so that "we dissect nature along lines laid down by our native languages," as the linguist Benjamin L. Whorf asserted half a century ago? Is language a straitjacket?

Perhaps to some extent, allows Paul Kay, 69, emeritus professor of linguistics at the University of California at Berkeley. Those are hardly fighting words, and Kay, dressed in fuzzy shoes and a fuzzy sweater, his feet up on his desk, doesn't seem a pugnacious fellow. Yet he and his former colleague, Brent Berlin (now at the University of Georgia), have been at the center of a 35-year running debate concerning Whorfs hypothesis, called linguistic relativity. "Our work has been interpreted by some people as undermining linguistic relativity, but it applies only to a very restricted domain: color," Kay remarks.

The Other Half of the Brain; April 2004; Scientific American Magazine; by R. Douglas Fields; 8 Page(s)

The recent book Driving Mr. Albert tells the true story of pathologist Thomas Harvey, who performed the autopsy of Albert Einstein in 1955. After finishing his task, Harvey irreverently took Einstein's brain home, where he kept it floating in a plastic container for the next 40 years. From time to time Harvey doled out small brain slices to scientists and pseudoscientists around the world who probed the tissue for clues to Einstein's genius. But when Harvey reached his 80s, he placed what was left of the brain in the trunk of his Buick Skylark and embarked on a road trip across the country to return it to Einstein's granddaughter.

One of the respected scientists who examined sections of the prized brain was Marian C. Diamond of the University of California at Berkeley. She found nothing unusual about the number or size of its neurons (nerve cells). But in the association cortex, responsible for high-level cognition, she did discover a surprisingly large number of nonneuronal cells known as glia - a much greater concentration than that found in the average Albert's head.

The Hidden Members of Planetary Systems; April 2004; Scientific American Magazine; by David R. Ardila; 8 Page(s)

Does our solar system represent the rule or the exception? Do similar collections of worlds surround other stars in the galaxy, or is the sun peculiar? Although this is one of the fundamental questions driving modern astronomy, the answer remains elusive. Over the past nine years, astronomers have discovered at least 111 planets around sunlike stars by looking for the slight back-and-forth motion that these bodies impart to their parent suns. Yet this technique detects only the most massive and tightly orbiting objects. If extraterrestrial astronomers applied the same method to our solar system, they might manage to identify Jupiter, and maybe Saturn, but they would completely miss the smaller bodies that make the suns family so rich and varied: asteroids, comets and the terrestrial planets.

How can astronomers detect those smaller bodies and paint a more complete picture of the diversity of planetary systems? A clue appears in the western sky in the spring, right after sunset. If you watch closely, you might see the zodiacal light, a faint triangle of light extending up from the horizon. The zodiacal light is produced by sunlight bouncing off interplanetary dust particles in our solar system. The triangle of light stretches along the suns path in the sky, indicating that the dust forms a disk in the plane of Earths orbit. What makes the dust interesting is that it should not be there. The individual dust particles are so small - about 20 to 200 microns across, judging from the color of the zodiacal light - that sunlight quickly causes them to spiral into the sun and burn up. Dust particles that are even smaller are quickly blown away from the solar system by radiation pressure. Therefore, for dust to be present it must be replenished continuously.

The Tyranny of Choice; April 2004; Scientific American Magazine; by Barry Schwartz; 6 Page(s)

Americans today choose among more options in more parts of life than has ever been possible before. To an extent, the opportunity to choose enhances our lives. It is only logical to think that if some choice is good, more is better; people who care about having infinite options will benefit from them, and those who do not can always just ignore the 273 versions of cereal they have never tried. Yet recent research strongly suggests that, psychologically, this assumption is wrong. Although some choice is undoubtedly better than none, more is not always better than less.

This evidence is consistent with large-scale social trends. Assessments of well-being by various social scientists - among them, David G. Myers of Hope College and Robert E. Lane of Yale University - reveal that increased choice and increased affluence have, in fact, been accompanied by decreased well-being in the U.S. and most other affluent societies. As the gross domestic product more than doubled in the past 30 years, the proportion of the population describing itself as "very happy" declined by about 5 percent, or by some 14 million people. In addition, more of us than ever are clinically depressed. Of course, no one believes that a single factor explains decreased well-being, but a number of findings indicate that the explosion of choice plays an important role.

The First Nanochips; April 2004; Scientific American Magazine; by G. Dan Hutcheson; 8 Page(s)

For most people, the notion of harnessing nanotechnology for electronic circuitry suggests something wildly futuristic. In fact, if you have used a personal computer made in the past few years, your work was most likely processed by semiconductors built with nanometer-scale features. These immensely sophisticated microchips - or rather, nanochips - are now manufactured by the millions, yet the scientists and engineers responsible for their development receive little recognition. You might say that these people are the Rodney Dangerfields of nanotechnology. So here I would like to trumpet their accomplishments and explain how their efforts have maintained the steady advance in circuit performance to which consumers have grown accustomed.

The recent strides are certainly impressive, but, you might ask, is semiconductor manufacture really nanotechnology? Indeed it is. After all, the most widely accepted definition of that word applies to something with dimensions smaller than 100 nanometers, and the first transistor gates under this mark went into production in 2000. Integrated circuits coming to market now have gates that are a scant 50 nanometers wide. That's 50 billionths of a meter, about a thousandth the width of a human hair.

Evolution Encoded; April 2004; Scientific American Magazine; by Stephen J. Freeland and Laurence D. Hurst; 8 Page(s)

On April 14, 2003, scientists announced to the world that they had finished sequencing the human genome - logging the three billion pairs of DNA nucleotides that describe how to make a human being. But finding all the working genes amid the junk in the sequence remains a further challenge, as does gaining a better understanding of how and when genes are activated and how their instructions affect the behavior of the protein molecules they describe. So it is no wonder that Human Genome Project leader Francis S. Collins has called the group's accomplishment only "the end of the beginning."

Collins was also alluding to an event commemorated that same week: the beginning of the beginning, 50 years earlier, when James D. Watson and Francis H. Crick revealed the structure of the DNA molecule itself. That, too, was an exciting time. Scientists knew that the molecule they were finally able to visualize contained nothing less than the secret of life, which permitted organisms to store themselves as a set of blueprints and convert this stored information back into live metabolism. In subsequent years, attempts to figure out how this conversion took place captivated the scientific world. DNA's alphabet was known to consist of only four types of nucleotide. So the information encoded in the double helix had to be decoded according to some rules to tell cells which of 20 amino acids to string together to constitute the thousands of proteins that make up billions of life-forms. Indeed, the entire living world had to be perpetually engaged in frenetic decryption, as eggs hatched, seeds germinated, fungus spread and bacteria divided.

Blastoffs on a Budget; April 2004; Scientific American Magazine; by Joan C. Horvath; 6 Page(s)

Well into the 1860s, the American West remained divided from the East by the harsh terrain of the country's broad, untamed interior, particularly the steep peaks of the Sierra Nevada. Then four Sacramento merchants began raising money to fund a seemingly impossible project: to build a railroad across the high Sierras and thus unite the continent. Derided by the press, the moneymen, top engineers and politicians, the ambitious enterprise nonetheless overcame daunting technical obstacles and eventually succeeded. The so-called Big Four investors, Collis P. Huntington, Mark Hopkins, Charles Crocker and Leland Stanford, became enormously rich as settlers arrived in the newly opened lands. Railroads prospered from the short-haul traffic for a burgeoning population they helped to create.

" Today a group of entrepreneurs has a comparable but loftier aim: to provide cheap, reliable transportation to low Earth orbit. Their high-flying goal comes with similarly steep challenges. Like the rail pioneers, private rocket builders are trying to create a market where none currently exists while keeping costs affordable. Further, they must develop a regular taxi service to space that is sufficiently safe to attract customers. (It will be some time before any flights to space will be as safe as passenger airline flights, though.) Finally, the entrepreneurs must surmount evolving governmental regulatory hurdles."

Working Knowledge: Complete Burn; April 2004; Scientific American Magazine; by Mark Fischetti; 2 Page(s)

"Hey, this sporty model is hot," the auto salesman raves. "It's got sequential multipoint fuel injection!" Yeah, well, so does virtually every other passenger vehicle now in production.

For decades, the good old carburetor acted like a funnel that allowed gasoline and air to be sucked into a car engine's cylinders. Spark plugs ignited the mixture in mini explosions that drove the pistons. The carburetor worked well enough but struggled to finely control the fuel-to-air ratio or even to deliver gasoline equally to each cylinder, limiting fuel economy and creating pollutants and rough engine operation.

Technicalities: Plug-and-Play Robots; April 2004; Scientific American Magazine; by W. Wayt Gibbs; 3 Page(s)

"Could this be the place?" I wonder as I stand before a nondescript storefront, formerly a tattoo parlor, in the tiny borough of Youngwood, Pa. The windows are covered by blinds; the door bears forbidding bars. The building lacks a sign or even a house number. It seems an odd location from which to launch an ambitious new species of robot.

But when Thomas J. Burick opens the door and I see three prototype "PC-Bots" sitting on his small workbench, I realize that this 34-year-old entrepreneur is no ordinary inventor. The half-meter-high robots look like R2-D2 droids that have been redesigned by Cadillac. Burick says that he spent a year honing their appearance, something almost unheard of in serious robotics, where function usually trumps form.

Reviews: The Brain in Love; April 2004; Scientific American Magazine; by Barbara Smuts, Staff Editors; 2 Page(s)

A male baboon named Sherlock sat on a cliff, unable to take his eyes off his favorite female, Cybelle, as she foraged far below. Each time Cybelle approached another adult male, Sherlock froze with tension, only to relax again when she ignored a potential rival. Finally, Cybelle glanced up and met his gaze. Instantly Sherlock flattened his ears and narrowed his eyes in what baboon researchers call the come-hither face. It worked; seconds later Cybelle sat by her guy, grooming him with gusto.

After observing many similar scenarios, I realized that baboons, like humans, develop intense attractions to particular members of the opposite sex. Baboon heterosexual partnerships bear an intriguing resemblance to ours, but they also differ in important ways. For instance, baboons can simultaneously be "in love" with more than one individual, a capacity that, according to anthropologist Helen Fisher, most humans lack.

Puzzling Adventures: Bluffhead; April 2004; Scientific American Magazine; by Dennis E. Shasha; 1 Page(s)

In my gambling years, between the ages of eight and 12, I played roulette, poker, blackjack and any other game that had a three-cent ante. One of my favorite games, though, was one we called "Bluffhead." Each person takes a card from a shuffled deck and holds it, face out, to his or her forehead. In other words, players see everyone elses cards but not their own. The best card wins. Ace is high and suits don't matter, so ties are possible.

This puzzle has to do with inferring information about the cards people hold by hearing what the players say. To be concrete, suppose that we have three players. Caroline always speaks first, then David, then Jordan, and back to Caroline and so on. Each player makes one of the statements listed at the bottom right of this page. Assume the players are perfect logicians and reveal information only through these phrases; also, they say the strongest thing they can - that is, they choose the statement that is true and highest on the list.

Anti Gravity: Visiting Royalty; April 2004; Scientific American Magazine; by Steve Mirsky; 1 Page(s)

There are many compelling vistas for the traveler heading west of Mexico City on Route 15. The extinct Nevado de Toluca volcano, for example, dominates the scene to the left. Within its now quiet caldera lie two lakes, which, at an altitude of more than 15,000 feet, are among the highest places in the world where people scuba dive. The volcanos lakes thus offer the opportunity to get altitude sickness and the bends at the same time.

Then there are the views to the right as Route 15 turns from a busy highway into a twisting, two-lane mountain road. Pondering the sheer drops from the switchbacks my bus is negotiating can be the cause of - or cure for, depending on one's particular physiology - the gastrointestinal problems this part of the world is famous for inadvertently inflicting on gringos like me.

Ask the Experts; April 2004; Scientific American Magazine; by Staff Editor; 1 Page(s)

Dimples reduce drag and improve lift, so golf balls fly farther. A smooth golf ball hit by a professional would travel only about half as far as one with dimples.

Engineers and scientists in the golf industry study the impact between a golf club and a ball to determine the so-called launch conditions. The impact, which typically lasts just 1D2,000 of a second, establishes the ball's velocity, launch angle and spin rate. Gravity and aerodynamics then take over the ball's trajectory (no matter how much the golfer hopes or curses). As a result, aerodynamic optimization - achieved through dimple-pattern design - is critical.

Fuzzy Logic; April 2004; Scientific American Magazine; by Roz Chast; 1 Page(s)

Avian Influenza

2008-02-22T13:08:00.000-08:00

abstract

Position-specific entropy profiles created from scanning 306 human and 95 avian influenza A viral genomes showed that 228 of 4,591 amino acid residues yielded significant differences between these 2 viruses. We subsequently used 15,785 protein sequences from the National Center for Biotechnology Information (NCBI) to assess the robustness of these signatures and obtained 52 "species-associated" positions. Specific mutations on those points may enable an avian influenza virus to become a human virus. Many of these signatures are found in NP, PA, and PB2 genes (viral ribonucleoproteins [RNPs]) and are mostly located in the functional domains related to RNP-RNP interactions that are important for viral replication. Upon inspecting 21 human-isolated avian influenza viral genomes from NCBI, we found 19 that exhibited ≥1 species-associated residue changes; 7 of them contained ≥2 substitutions. Histograms based on pairwise sequence comparison showed that NP disjointed most between human and avian influenza viruses, followed by PA and PB2.
Introduction

Pandemic influenza A virus infections have occurred 3 times during the past century; the 1957 (H2N2) and 1968 (H3N2) pandemic strains emerged from a reassortment of human and avian viruses.[1] Recently, all 8 genome segments from the 1918 (H1N1) influenza A virus were completely sequenced. The results indicate that the 1918 pandemic virus may not have emerged by a reassortment of avian and human virus as did the 2 other pandemic strains. Although the 1918 H1N1 is not considered an avian virus, it is the most avianlike of all mammalian influenza viruses.[2,3] The recent circulation of highly pathogenic avian H5N1 viruses in Asia from 2003 to 2006 has caused ≥90 human deaths and has raised concern about a new pandemic.[4] Therefore, we need to understand what genetic variations could render avian influenza virus capable of becoming a pandemic strain. Genomewide comparison of human versus avian influenza A viruses would show the evolutionary similarities and differences between them and thus provide information for studying the mechanism of influenza viral infection and replication in different host species.

Although many research efforts have focused on the molecular evolution of specific genes of influenza viruses, comprehensive comparisons among the nucleotide sequences of all 8 genomic segments and among the 11 encoded protein sequences have not been extensively reported. In this study, we used several computational approaches for finding specific genetic signatures characteristic of human and avian influenza A viral genomes. We subsequently validated the robustness of those signatures with human and avian protein sequences downloaded from Influenza Virus Resources at the National Center for Biotechnology Information (NCBI) (http://www.ncbi.nlm.nih.gov/genomes/FLU/FLU.html).
Clinical Isolates

Throat swabs from patients with influenzalike syndromes were collected from the Clinical Virology Laboratory, Chang Gung Memorial Hospital. The specimens were inoculated in MDCK cells. Typing for influenza A virus was then performed with immunofluorescent assay by type-specific monoclonal antibody (Dako, Cambridgeshire, UK). Subtyping was conducted by reverse transcription (RT)-PCR with subtype-specific primers.
Sequence Analysis

The RT-PCR product was purified by using the QIAquick Gel Extraction Kit (Qiagen, Valencia, CA, USA). The nucleotide sequence was determined with an automated DNA sequencer. Sequence editing and processing were performed with Lasergene, version 3.18 (DNASTAR, Madison, WI, USA). Multiple sequence alignment was performed with ClustalW version 1.83 (ftp://ftp.ebi.ac.uk/pub/software/unix/clustalw). Global sequence comparison that yielded pairwise sequence identities used in histogram analysis was done with the program Needle in the EMBOSS package.[5] Amino acid sequences were translated from coding sequences and aligned by BioEdit.[6] An entropy value was defined at an aligned amino acid position according to the formula ΣPi*log(Pi), in which i is the observed probability for each of the 20 amino acids (aa).[7] A graphic tool was developed in Java for displaying the entropy plot used in this work. All amino acid numberings are based on influenza virus A/Puerto Rico/8/1934 (PR8).
Sequences Used in Study

To show the host-associated amino acid signatures, we retrieved full genome sequences (as of August 22, 2005) from the genome browser at Influenza Sequence Database (ISD).[8] To differentiate between avian and human influenza viruses, we excluded human-isolated avian influenza viruses from the human dataset and examined those sequences separately. Altogether, we had 95 avian and 306 human influenza viral genomes, henceforth termed "primary dataset." All 11 viral proteins encoded by the 8 genomic RNA segments were compared: PB2, PB1, PB1-F2, PA, HA, NP, NA, M1, M2, NS1, and NS2.

Avian influenza viruses from human influenza patients were separately retrieved from NCBI as well as from ISD. Altogether, we had 417 protein sequences from 60 avian influenza strains, in which 21 strains contain sequences (full or nearly full length) from all 8 genomic RNA segments.

For validating the signatures obtained from analyzing the primary dataset, we further retrieved 15,785 human or avian influenza A viral protein sequences from NCBI's Influenza Virus Resources. Details for the sequences used can be found in Appendix, Supporting Materials and Methods, as well as in Appendix Table 1 and Appendix Table 2. Eleven Taiwanese genomes produced in this work have been deposited in GenBank with accession numbers DQ415283 through DQ415370.

Harvard Biovisions - The Inner Life of a Cell

2008-02-20T09:41:00.000-08:00

Urinary Tract Infections

2008-02-19T09:14:00.000-08:00

Urinary Tract Infections During Pregnancy
What is a urinary tract infection?
Urinary tract infections (UTI) are caused by bacteria. The most common type of UTI is a bladder infection. Other types of UTIs are kidney infections and infections of the urethra. The urethra is the small tube that goes from the bladder to the outside of your body.

How do I know if I have a UTI?
UTIs may cause different symptoms in different people. You may feel a burning when you urinate. You may need to urinate more often, sometimes 30 to 60 minutes later. Or, you may feel like you need to go again right after you've just urinated. You may notice blood in your urine or a strong odor.

Sometimes germs can grow in the urinary tract but you won't have any of these symptoms. This is called asymptomatic (pronounced: "a-simp-toe-mat-ik") bacteriuria. Your doctor can test to find out if you have this. Asymptomatic bacteriuria should be treated in pregnant women, but doesn't need to be treated in most other women.

How will the UTI affect my baby?
If you have a UTI and it isn't treated, it may lead to a kidney infection. Kidney infections may cause early labor. Fortunately, asymptomatic bacteriuria and bladder infections can usually be found and treated before the kidneys become infected. If your doctor treats a urinary tract infection early and properly, it won't hurt your baby.

How do you treat a UTI?
Your doctor will prescribe a medicine that is safe for you and the baby. You can help by drinking a lot of water to help flush the germs from your urine.

How do I know if the treatment isn't working?
If you have a fever (over 100.5 degrees), chills, lower stomach pains, nausea, vomiting or flank pain, you should call your doctor. You should also call your doctor if you have any contractions, or if, after taking medicine for 3 days, you still have a burning feeling when you urinate.

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Can I keep this from happening again?
You can help prevent UTIs in several ways. First, you should always drink plenty of liquids (water is the best). You should urinate often. Don't wait for long periods of time before you urinate. Always urinate after sexual intercourse. After you urinate, always wipe from front to back.

Lumbar disc disease animation

2008-02-17T10:25:00.000-08:00

Lumbar disc disease accounts for a large amount of lost productivity in the workforce. Accurate diagnosis can be difficult and often requires interpretation. Treatment is controversial. Surgical treatment can be technically simple and professionally gratifying for the surgeon. Treatment failures are not uncommon, are often related to posttraumatic or work-related injuries, and may result in litigation. As a consequence, this disease can generate distrust of physicians on the part of patients and vice versa.

This article clarifies some important guidelines for the diagnosis and treatment of lumbar disc disease.

History of the Procedure: The first published report of lumbar disc herniation with radiculopathy was written by Mixter and Barr in 1934. Surgical treatment was not widespread until the 1950s. Today, lumbar discectomy is one of the most commonly performed elective operations in the United States.

Problem: Lumbar disc disease is a rather encompassing term. For example, some physicians include back pain alone as a symptom of disc disease. Others make the diagnosis without evidence of disc disease on MRI. The discussion of this article is limited to well-defined lumbar disc herniation. The pathophysiology, clinical presentation, radiographic diagnosis, treatment, and outcome are discussed.

Frequency: Although most people experience back pain during their lifetime, only a fraction experience lumbar radiculopathy or sciatica as a consequence of root compression or irritation.

Almost 5% of males and 2.5% of females experience sciatica at some time in their lifetime.

Etiology: A herniated disk fragment comes from the nucleus pulposus of the disc (a remnant of the embryonic notochord). In the normal condition, this nucleus is in the disk center securely contained by the annulus fibrosus.

When a fragment of nucleus herniates, it irritates and/or compresses the adjacent nerve root. This can cause the pain syndrome known as sciatica and, in severe cases, dysfunction of the nerve.

Clinical: Most lumbar disc herniations are preceded by bouts of varying degrees and duration of back pain. In many cases, an inciting event cannot be identified. Pain eventually may radiate into the leg. It may be characterized as less achy, burning, or similar to an electrical shock and is often described as a shooting or stabbing pain. The distribution of the leg pain is somewhat dependent on the level of nerve root irritation. Higher herniations (third or fourth lumbar levels) can radiate into the groin or anterior thigh. Lower radiculopathies (first sacral level) cause pain in the calf and bottom of the foot.

Fifth lumbar radiculopathy, which occurs most commonly, causes lateral and anterior thigh and leg pain. Often, accompanying numbness or tingling occurs with a distribution similar to the pain. Accompanying muscle weakness may be unrecognized if the pain is incapacitating. The pain usually improves when the patient is in the supine position with the legs slightly elevated. Patients are more comfortable when changing positions. Short walks can bring relief. Long walks or extended sitting (especially driving) can aggravate the pain.

On examination, patients may be neurologically normal, may have a profound radiculopathy, or may even demonstrate a cauda equina syndrome. A positive straight-leg raising sign is almost always present. However, a crossed straight-leg raising sign may be even more predictive of a lumbar disc herniation. The back may appear scoliotic. Gait is often abnormal. Muscle weakness may be revealed particularly when testing walking on heels and toes.

DNA animation

2008-02-15T11:12:00.000-08:00

What is DNA?

DNA, or deoxyribonucleic acid, is the hereditary material in humans and almost all other organisms. Nearly every cell in a person’s body has the same DNA. Most DNA is located in the cell nucleus (where it is called nuclear DNA), but a small amount of DNA can also be found in the mitochondria (where it is called mitochondrial DNA or mtDNA).

The information in DNA is stored as a code made up of four chemical bases: adenine (A), guanine (G), cytosine (C), and thymine (T). Human DNA consists of about 3 billion bases, and more than 99 percent of those bases are the same in all people. The order, or sequence, of these bases determines the information available for building and maintaining an organism, similar to the way in which letters of the alphabet appear in a certain order to form words and sentences.

DNA bases pair up with each other, A with T and C with G, to form units called base pairs. Each base is also attached to a sugar molecule and a phosphate molecule. Together, a base, sugar, and phosphate are called a nucleotide. Nucleotides are arranged in two long strands that form a spiral called a double helix. The structure of the double helix is somewhat like a ladder, with the base pairs forming the ladder’s rungs and the sugar and phosphate molecules forming the vertical sidepieces of the ladder.

An important property of DNA is that it can replicate, or make copies of itself. Each strand of DNA in the double helix can serve as a pattern for duplicating the sequence of bases. This is critical when cells divide because each new cell needs to have an exact copy of the DNA present in the old cell.

Medical animation of nerve synapse

2008-02-13T13:18:00.000-08:00

A Short History of the Treatment of Spinal Cord Injury

Accounts of spinal cord injuries and their treatment date back to ancient times, even though there was little chance of recovery from such a devastating injury. The earliest is found in an Egyptian papyrus roll manuscript written in approximately 1700 B.C. that describes two spinal cord injuries involving fracture or dislocation of the neck vertebrae accompanied by paralysis.* The description of each was "an ailment not to be treated."

Centuries later in Greece, treatment for spinal cord injuries had changed little. According to the Greek physician Hippocrates (460-377 B.C.) there were no treatment options for spinal cord injuries that resulted in paralysis; unfortunately, those patients were destined to die. But Hippocrates did use rudimentary forms of traction to treat spinal fractures without paralysis. The Hippocratic Ladder was a device that required the patient to be bound, tied to the rungs upside-down, and shaken vigorously to reduce spinal curvature. Another invention, the Hippocratic Board, allowed the doctor to apply traction to the immobilized patient's back using either his hands and feet or a wheel and axle arrangement.

Hindu, Arab, and Chinese physicians also developed basic forms of traction to correct spinal deformities. These same principles of traction are still applied today.

In about 200 A.D., the Roman physician Galen introduced the concept of the central nervous system when he proposed that the spinal cord was an extension of the brain that carried sensation to the limbs and back. By the seventh century A.D., Paulus of Aegina was recommending surgery for spinal column fracture to remove the bone fragments that he was convinced caused paralysis.

In his influential anatomy textbook published in 1543, the Renaissance physician and teacher Vesalius described and illustrated the spinal cord in all its parts. The illustrations in his books, based on direct observation and dissection of the spine, gave physicians a way to understand the basic structure of the spine and spinal cord and what could happen when it was injured. The words we use today to identify segments of the spine - cervical, thoracic, lumbar, sacral, and coccygeal - come directly from Vesalius.

With the widespread use of antiseptics and sterilization in surgical procedures in the late nineteenth century, spinal surgery could finally be done with a much lower risk of infection. The use of X-rays, beginning in the 1920s, gave surgeons a way to precisely locate the injury and also made diagnosis and prediction of outcome more accurate. By the middle of the twentieth century, a standard method of treating spinal cord injuries was established - reposition the spine, fix it in place, and rehabilitate disabilities with exercise. In the 1990s, the discovery that the steroid drug methylprednisolone could reduce damage to nerve cells if given early enough after injury gave doctors an additional treatment option.
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What Is a Spinal Cord Injury?

Although the hard bones of the spinal column protect the soft tissues of the spinal cord, vertebrae can still be broken or dislocated in a variety of ways and cause traumatic injury to the spinal cord. Injuries can occur at any level of the spinal cord. The segment of the cord that is injured, and the severity of the injury, will determine which body functions are compromised or lost. Because the spinal cord acts as the main information pathway between the brain and the rest of the body, a spinal cord injury can have significant physiological consequences.

Catastrophic falls, being thrown from a horse or through a windshield, or any kind of physical trauma that crushes and compresses the vertebrae in the neck can cause irreversible damage at the cervical level of the spinal cord and below. Paralysis of most of the body including the arms and legs, called quadriplegia, is the likely result. Automobile accidents are often responsible for spinal cord damage in the middle back (the thoracic or lumbar area), which can cause paralysis of the lower trunk and lower extremities, called paraplegia.

Other kinds of injuries that directly penetrate the spinal cord, such as gunshot or knife wounds, can either completely or partially sever the spinal cord and create life-long disabilities.

Most injuries to the spinal cord don't completely sever it. Instead, an injury is more likely to cause fractures and compression of the vertebrae, which then crush and destroy the axons, extensions of nerve cells that carry signals up and down the spinal cord between the brain and the rest of the body. An injury to the spinal cord can damage a few, many, or almost all of these axons. Some injuries will allow almost complete recovery. Others will result in complete paralysis.

Until World War II, a serious spinal cord injury usually meant certain death, or at best a lifetime confined to a wheelchair and an ongoing struggle to survive secondary complications such as breathing problems or blood clots. But today, improved emergency care for people with spinal cord injuries and aggressive treatment and rehabilitation can minimize damage to the nervous system and even restore limited abilities.

Advances in research are giving doctors and patients hope that all spinal cord injuries will eventually be repairable. With new surgical techniques and exciting developments in spinal nerve regeneration, the future for spinal cord injury survivors looks brighter every day.

This brochure has been written to explain what happens to the spinal cord when it is injured, the current treatments for spinal cord injury patients, and the most promising avenues of research currently under investigation.

Facts and Figures About Spinal Cord Injury

* There are an estimated 10,000 to 12,000 spinal cord injuries every year in the United States.
* A quarter of a million Americans are currently living with spinal cord injuries.
* The cost of managing the care of spinal cord injury patients approaches $4 billion each year.
* 38.5 percent of all spinal cord injuries happen during car accidents. Almost a quarter, 24.5 percent, are the result of injuries relating to violent encounters, often involving guns and knifes. The rest are due to sporting accidents, falls, and work-related accidents.
* 55 percent of spinal cord injury victims are between 16 and 30 years old.
* More than 80 percent of spinal cord injury patients are men

Source: Facts and Figures at a Glance, May 2001. National Spinal Cord Injury Statistical Center.

Herniated Disk: What It Is and What You Can Do

2008-02-12T09:05:00.000-08:00

What is a herniated disk?
Lumbar spine
Herniated disks are most common in the lumbar spine--the part of your backbone between the bottom of your ribs and your hips. Disks are the soft "cushions" between the bones of the spine. The disks in the spine let you move your backbone.

When a disk between two bones in the spine presses on the nerves around the backbone, it's called a herniated disk. The word "herniate" (say: her-nee-ate) means to bulge or to stick out. Sometimes this is called a ruptured or slipped disk.

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Why does a disk get herniated?
Herniated disk
As you grow older, your disks become flatter -- less cushiony. If a disk becomes too weak, the outer part may tear. The inside part of the disk pushes through the tear and presses on the nerves beside it. The drawing to the right shows how a disk looks when it gets pushed through the tear and presses on a nerve. Herniated disks are most common in people in their 30s and 40s.

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What are the signs of a herniated disk?
When part of a disk presses on a nerve, it can cause pain in both the back and the legs. The location of the pain depends on which disk is weak. How bad the pain is depends on how much of the disk is pressing on the nerve. In most people with herniated disks, the pain spreads over the buttocks and goes down the back of one thigh and into the calf. Some people have pain in both legs. Some people's legs or feet feel numb or tingly.

The pain from a herniated disk is usually worse when you're active and gets better when you're resting. Coughing, sneezing, sitting, driving and bending forward may make the pain worse. The pain gets worse when you make these movements because they put more pressure on the nerve.

People with painful herniated disks often try to change positions to reduce the pain. You may have found that holding yourself up with your hands while you are sitting helps the pain. Shifting your weight to one side may also help.

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How does my doctor know I have a herniated disk?
After asking you questions and giving you an exam, your doctor may take x-rays and other pictures to see whether you have a herniated disk.

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What can be done for the pain of a herniated disk?
Your doctor may suggest medicine for the pain. You can probably be more active after you take the pain medicine for 2 days. Becoming active will help you get better faster. If your pain is severe, your doctor may suggest that you rest in bed for 1 or 2 days.

If the pain medicine doesn't help, your doctor may give you a shot in your backbone. This might stop your pain. You may need more than 1 shot.

Sometimes stretching of the spine, by your doctor or a chiropractor, can help the pain.

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Will exercises help the pain?
Yes, exercises can be helpful. Begin by stretching. Bend over forward and bend to the sides. Start these exercises after your back is a little stronger and doesn't hurt as much. The goal of exercise is to make your back and stomach muscles stronger. This will ease the pressure on your disk and make you hurt less. Ask your doctor about exercises for your back. Your doctor may want you to see a physical therapist to learn about safe back exercises.

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What about my posture?
Good posture
Good posture (standing up straight, sitting straight, lifting with your back straight) can help your back by reducing the pressure on your disk

1. Bend your knees and hips when you lift something, and keep your back straight.
2. Hold an object close to your body when you carry it.
3. If you stand for a long time, put one foot on a small stool or box for a while.
4. If you sit for a long time, put your feet on a small stool so your knees are higher than your hips.
5. Don't wear high-heeled shoes.
6. Don't sleep on your stomach.

The pictures on this page show good posture in standing and lifting.

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What are my chances of getting better?
Your chances are good. Most people with a herniated disk are better in about 4 weeks. Sometimes it takes longer. If you still have pain or numbness after 4 to 6 weeks, or if your signs get worse, talk with your doctor. Sometimes it takes surgery to relieve pain.

If you have trouble going to the bathroom or have weight loss, pain at night or more pain or weakness than usual in your backbone, tell your doctor right away. These might be the signs of a more serious problem.

Mitosis animation

2008-02-11T08:55:00.000-08:00

Events during Mitosis

Interphase: Cells may appear inactive during this stage, but they are quite the opposite. This is the longest period of the complete cell cycle during which DNA replicates, the centrioles divide, and proteins are actively produced. For a complete description of the events during Interphase, read about the Cell Cycle.

Prophase: During this first mitotic stage, the nucleolus fades and chromatin (replicated DNA and associated proteins) condenses into chromosomes. Each replicated chromosome comprises two chromatids, both with the same genetic information. Microtubules of the cytoskeleton, responsible for cell shape, motility and attachment to other cells during interphase, disassemble. And the building blocks of these microtubules are used to grow the mitotic spindle from the region of the centrosomes.

Prometaphase: In this stage the nuclear envelope breaks down so there is no longer a recognizable nucleus. Some mitotic spindle fibers elongate from the centrosomes and attach to kinetochores, protein bundles at the centromere region on the chromosomes where sister chromatids are joined. Other spindle fibers elongate but instead of attaching to chromosomes, overlap each other at the cell center.

Metaphase: Tension applied by the spindle fibers aligns all chromosomes in one plane at the center of the cell.

Anaphase: Spindle fibers shorten, the kinetochores separate, and the chromatids (daughter chromosomes) are pulled apart and begin moving to the cell poles.

Telophase: The daughter chromosomes arrive at the poles and the spindle fibers that have pulled them apart disappear.

Cytokinesis: The spindle fibers not attached to chromosomes begin breaking down until only that portion of overlap is left. It is in this region that a contractile ring cleaves the cell into two daughter cells. Microtubules then reorganize into a new cytoskeleton for the return to interphase.

Medical animation of a heart

2008-02-09T12:41:00.000-08:00

Heart Diseases

Also called: Cardiac disease

If you're like most people, you think that heart disease is a problem for other folks. But heart disease is the number one killer in the U.S. It is also a major cause of disability. There are many different forms of heart disease. The most common cause of heart disease is narrowing or blockage of the coronary arteries, the blood vessels that supply blood to the heart itself. This is called coronary artery disease and happens slowly over time. It's the major reason people have heart attacks.

Other kinds of heart problems may happen to the valves in the heart, or the heart may not pump well and cause heart failure. Some people are born with heart disease.

You can help reduce your risk of heart disease by taking steps to control factors that put you at greater risk:

* Control your blood pressure
* Lower your cholesterol
* Don't smoke
* Get enough exercise

What Is Cardiac Catheterization?

Cardiac catheterization (KATH-e-ter-i-ZA-shun) is a medical procedure used to diagnose and treat certain heart conditions. A long, thin, flexible tube called a catheter is put into a blood vessel in your arm, groin (upper thigh), or neck and threaded to your heart. Through the catheter, doctors can perform diagnostic tests and treatments on your heart.

Sometimes a special dye is put into the catheter to make the insides of your heart and blood vessels show up on x rays. The dye can show whether a material called plaque (plak) has narrowed or blocked any of your heart’s arteries (called coronary arteries).

Plaque is made up of fat, cholesterol, calcium, and other substances found in your blood. The buildup of plaque narrows the inside of the arteries and, in time, may restrict blood flow to your heart. When this happens, it’s called coronary artery disease (CAD).

Blockages in the arteries also can be seen using ultrasound during cardiac catheterization. Ultrasound uses sound waves to create detailed pictures of the heart’s blood vessels.

Doctors may take samples of blood and heart muscle during cardiac catheterization, as well as do minor heart surgery.

Cardiologists (doctors who specialize in treating people who have heart problems) usually perform cardiac catheterization in a hospital. You’re awake during the procedure, and it causes little to no pain, although you may feel some soreness in the blood vessel where your doctor put the catheter. Cardiac catheterization rarely causes serious complications.

how a child created

2008-02-08T10:33:00.001-08:00

THE MUSCULAR MECHANISM OF WALKING.

2008-02-07T12:21:00.000-08:00

THE MUSCULAR MECHANISM OF WALKING. By W.
RAMSAY SMITH, B.Sc., Demornstrator of Anatomy, Edinburgh
School of Medicine, Minto House.
THERE are certain functions of the human body that appear
at first sight very easy to understand; but yet when one has
studied them for some time, with a few side lights cast upon
them, one hesitates to offer any opinion regarding them. Of
this nature are several problems possessing a psychical as well
as a physical aspect, such as binocular vision and hearing,
which, when brought to the touchstone of psychology and comparative
physiology, make a thinker hesitate to give an opinion
and a practical man to say in despair Solvitur arnbulando.
But there are also problems of a more purely physical nature,
whose solutions, apparently at first sight easy, present many
difficulties whenever one tries to bring a hypothesis face to face
with all the facts. A great deal has been done by way of
describing the mechanics of walking. W. and E. Weber, von
Meyer, Marey, Vierordt, Lucae, Carlet, Pettigrew, Ward, and
latest, Braune and Fischer,' have contributed to elucidate one
aspect of the problem; and Goodsir, Humphry, Morris, and
others have investigated another. But while much has been
done on the one hand to discover and record the movements of
the various phases of walking, and a large amount of study has
been bestowed upon the anatomical details of the organs of
locomotion on the other, there is a considerable hiatus in our
knowledge of the problem of walking; in other words, although
we know what acts are performed in walking, and what means
are at the disposal of the walker for performing those acts, we
have still to learn almost everything regarding the modes or
methods in which the means are employed.2
1 For a knowledge of the work of these two last investigators I am indebted to
Dr Symington, who also guided me to other literature and discussed several of
the points touched upon in this paper.
2 I ought to mention here Cleland's suggestive paper on "The Actions of
Muscles passing over more than one Joint " (Journal ofAnatomy and Physiology,
vol. i. p. 85), which I had not read when the above was written. It deals with
the subject of muscular action in the way I desiderate, and in some parts runs
on lines similar to those of my present communication.
THE MUSCULAR MECHANISM OF WALKING.
The incompleteness of our knowledge of the problem of walking
was pressed upon my attention by reading Cunningham on
the action of the knee-joint. In a passage that may be taken
as setting forth the generally received theory of the action of
certain muscles, he says-
"The muscles which operate upon the bones of the leg so as to
produce flexion and extension of the limb at the knee-joint are:
(1) extensors, the four parts of the quadriceps extensor; (2) flexors,
the biceps, popliteus, sartorius, gracilis, semitendinosus, and semimembranosus.
Of these, only one is inserted on the outer side of
the limb, viz., the biceps. The other five are inserted into the tibia
on the inner side of the leg. This preponderance of muscles attached
to the inner aspect of the leg is, no doubt, associated with the fact
that the first act in flexion is the unlocking of the joint by the rotation
of the tibia in an inward direction."-Mlanual of Practical
Anatomy, part i., pp. 429, 430.
Now, to give the history of the reasoning process that went
on in my mind, although it is true, as Goodsir and Meyer
showed, that the first motion of flexion is an unscrewing of the
knee-joint which the last movement of extension screwed home
or locked; and although it is also true that the human body is
a high-pressure engine working at a low pressure with great
reserve power for emergencies; yet the theory that such an
overbalance of power is applied on one aspect of the leg for the
purpose of overcoming such small resistance seems a breach of
the logical law of parsimony. And the doubt thereby raised of
the truth of this explanation became more established when
I considered, what any one can easily determine by a simple
experiment, that in walking the knee-joint is not locked and
unlocked as a necessary part of the act of progression. Some
people do lock one or both of their knee-joints in walking, but
the movement is not elegant, and it does not appear to give
either strength to the limb or comfort to the individual. And
although, as I shall show, the knee may be locked at either or
both of two positions of the step, the muscular power necessary
to unlock the joint must be very small indeed. What, then, is
the explanation of the preponderance of muscles inserted into
the inner aspect of the leg? In other words, with what other
muscular action can we correlate this, and so give some more
comprehensive and rational explanation of it?
567
MR W. RAMSAY SMITH.
On the assumption that one that puts up a notice, " No road
this way," confers almost as great a benefit as one that points
the road to truth, I might refrain from saying more on the
subject in case I be tempted to go astray by the hypothesis I
am about to propound. But it is only right to give a hypothesis
a chance of being criticised and tested; so I venture to
offer the following contribution to the subject of the muscular
mechanism of walking.
In walking, and also in running, the knee-joint is kept
slightly flexed, just short of being locked. In this position
there must be some contrivance whereby rotation of the tibia
on the femur is prevented, since such rotation is possible
when the joint is not locked. This contrivance is found in the
action of certain muscles, viz.-(l), the long head of the biceps
and the semitendinosus, which, arising from the same place,
proceed to and are inserted into opposite sides of the leg; (2),
the gastrocnemius, which acts from one point below and is
attached to opposite sides of the femur above; (3), two short
muscles, the short head of the biceps, and the popliteus, which
act in concert towards the same end. All these muscles, by
their combined action, tend to flex the leg upon the thigh;
at the same time they so balance one another as to prevent
rotation of the tibia upon the femur; and they also pull upon
the tibia and femur in such a manner as to cause considerable
pressure on the articular surfaces of these bones. The result of
this action is to make the thigh and leg very much a rigid
pillar, so far as regards rotation.
Now, to consider the muscles inserted on the inner aspect of
the leg. The movement of walking, so far as concerns the
muscles I am dealing with, may be regarded as consisting
essentially of an extension of the thigh upon the trunk, an
action that tends to extend the knee; but this tendency is
resisted by the action of the flexors of the knee-joint; so that
one may say that the movement of propulsion consists in extending
the hip-joint and flexing the knee. The gluteus maximus
is the great extensor of the thigh upon the trunk, and in producing
extension it tends to straighten the knee; at the same
time it tends to rotate the thigh and leg as a whole outwards,
568
THE MUSCULAR MECHANISM OF WALKING.
being inserted into the femur, and also, by means of the iliotibial
band, into the outer aspect of the tibia. When the gluteus
maximus contracts, the long head of the biceps and the semitendinosus
and semimembranosus also contract and help the
gluteus in extending the thigh upon the trunk, but resist the
action of that muscle so far as regards the extension of the
knee; at the same time, the semitendinosus and semimembranosus
counteract the tendency of the gluteus and biceps to
rotate the limb outwards. The gracilis and sartorius, so far as
they come into action, would assist in keeping the knee-joint
flexed, and would, at the same time, tend to rotate the limb
inwards. Now, such rotation would be prevented by the action
of the external rotators of the thigh at the hip-joint, and it is
probable that herein lies the explanation of the great preponderance
of power on the part of the external compared with the
internal rotators of the thigh, a matter which is inexplicable on
any other known hypothesis.
To state the matter briefly, I would say, then, that in propelling
the body forwards, as in ordinary running and walking,
the tibia is prevented from rotating on the femur, and is flexed
on the femur by certain muscles acting in pairs, while the
flexors inserted into the inner aspect of the tibia, considered as
a whole, act in concert with the great extensor and the external
rotators of the femur in extending the hip-joint, and in flexing
the knee, and in preventing rotation of the limb as a whole.
One or two points demand notice. With reference to the
commonly received theory, I wish to point out that it is possible
that the knee may be fully extended and locked just at the
moment when the limb is leaving the ground to take the pendulum-
swing forwards; but if it is, the flexors inserted into the
inner aspect of the leg have little if anything to do with the
action of unlocking, which may be accomplished by a very slight
muscular action. Again, the joint may be locked just when the
advancing foot has touched the ground; but if it is (and I
doubt the fact in the case of ordinary walking), the rolling
forwards of the body over the top of this limb by the propelling
act of the other obviates any great muscular force being required
to undo the locking of the joint.
569
THE MUSCULAR MECHANISM OF WALKING.
In this connection a series of careful observations on points
like the following would prove useful:-The condition of the
various muscles of the thigh at some considerable interval of
time after excision of the knee-joint; the effect of tenotomy of
the muscles of the ham; the source of the nerve supply of
the various muscles that may act in concert in producing
certain movements of the thigh. These are points that I can
do no more than refer to in this very general statement. But I
may point out that many combinations of muscles capable of
easy demonstration are generally quite overlooked in discussing
the movements of the hip and knee joints. For example, if, in
the sitting posture, the thigh is flexed from a right angle to an
acute angle with the trunk, a movement effected by the rectus
femoris and the illo-psoas, it will be found that the semimembranosus
comes into play. If the action of the semimembranosus
is not antagonistic to the outward rotating action of the
ilio-psoas it is very difficult to explain what its action in this
connection is. Again, in the act of walking with persistently
locked knee, or in cases where the leg is jerked forwards and
the knee is locked before the foot touches the ground, as practised
by some professional walkers and others, the whole power
of the biceps, semimembranosus, and semitendinosus is exerted
in extending the thigh, while the gracilis and sartorius are
exerted in flexing it; and here, I believe, one finds the true
economy of the locking apparatus of the knee-joint. But these
are subjects on which I cannot enter at present. My point will
have been gained if I have succeeded in directing attention
to the broad features presented by the muscular mechanism of
the thigh and leg employed in progression by walking.

Congenital heart disease: Don't overlook condition as an adult

2008-02-06T11:20:00.000-08:00

Congenital heart disease: Don't overlook condition as an adult

Congenital heart disease, once almost a guaranteed death sentence for babies born with heart defects, is far more treatable today than in the past. Although congenital heart disease is often considered a childhood disease, advances in surgical treatment mean most babies who once died of congenital heart disease are surviving well into adulthood. Some researchers estimate there are more adults than children living today with congenital heart disease.

Nearly 2 million adults and children in the United States have some form of congenital heart disease. Congenital heart disease is the most common form of birth defect, affecting about one out of every 100 babies. As treatments continue to improve, it's likely the number of adults with congenital heart disease will steadily rise.

While medical advances have improved, many adults with congenital heart disease may not be getting proper follow-up care. If you had a congenital heart defect repaired as an infant, don't consider yourself out of the woods. Learn if and when you should check with your doctor, if you're likely to have complications or if you're at greater risk of other heart problems as an adult.

How do I know if my congenital heart disease is causing problems now?

Congenital heart disease encompasses a wide variety of heart defects that are present at birth. Some are minor, while others require treatment. A congenital heart disease diagnosis is sometimes made during pregnancy, especially if special screening tests have been done. Many severe forms of congenital heart disease are detected at birth or in the first few months of life. However, symptoms or signs of congenital heart disease may not show up until later in life. They may recur years after you've had treatment for a defect. Some typical signs and symptoms you may have as an adult that may be related to congenital heart disease include:

Abnormal heart rhythms (arrhythmias)
A bluish tint to the skin (cyanosis)
Shortness of breath
Tiring quickly upon exertion
Dizziness or fainting
Swelling of body tissue or organs (edema)

A heart murmur is one clue your doctor may find that could indicate you have a lingering heart defect issue. After detecting the murmur, your doctor could order other tests to diagnose its cause or get a better idea of what's going on in your heart. Possible tests include:

Echocardiogram. An echocardiogram uses sound waves to produce images of the heart. Your doctor can use these images to identify heart abnormalities.
Cardiac catheterization. Your doctor may use this test to check blood flow in your heart. A catheter is inserted into an artery, starting in your groin, neck or arm. It's then carefully threaded to your heart chambers under guidance of an X-ray machine that shows real-time images of your body. Dye is injected through the catheter, and the X-ray machine makes images (angiograms) of your heart and blood vessels. The pressure in the heart chambers also can be measured during this same procedure.
Electrocardiogram (ECG). This test records the electrical activity of your heart. Some heart defects can disrupt the electrical signals in your heart, which in turn cause abnormal heart rhythms called arrhythmias. Patterns of the electrical signals can also provide clues about the presence of various forms of congenital heart disease.
Chest X-ray. X-ray images help your doctor further evaluate your heart and lungs.
Cardiac magnetic resonance imaging (MRI). Cardiac MRI is an imaging technique that uses magnetic fields and radio waves to create images of your heart.
Exercise stress test. An exercise stress test may be performed to check your overall level of conditioning and your heart's electrical activity, heart rate and blood pressure during exercise. For this test you'll exercise on a treadmill or bicycle, sometimes with special sensors to check how much oxygen you use during exercise.

Congenital heart disease rarely cured

One of the biggest myths many adults with congenital heart disease have is they no longer have to worry about congenital heart disease. Many think they've either outgrown their condition or that treatment they had as a child cured them. But this is rarely true.

If you have congenital heart disease, even if you've had surgery as a child, you're not cured. This doesn't mean you face a lifetime of problems. However, it does mean you're at increased risk of developing complications, such as infections of the heart (endocarditis) or dangerous abnormal heart rhythms. Some problems might require surgical treatment as you get older.

Follow-up care for congenital heart disease is essential

If you had your congenital heart defect or congenital heart disease treated as a child, it's important to have lifelong follow-up care, especially if you had corrective heart surgery. This follow-up care could be as simple as having periodic checkups with your doctor, or it may involve more comprehensive testing. The important thing is to discuss your care plan and make sure you follow all recommendations.

Ideally, your care will be done by cardiologists trained in following adults with congenital heart defects. This may be a challenge for some because there's currently a shortage of cardiologists with such expertise, as well as a limited number of centers that specialize in following adults with congenital heart disease.

Congenital heart disease problems that can arise as an adult

Congenital heart disease complications may not arise until years after treatment. Because the severity of congenital heart disease varies widely, the range of possible complications does, too. However, some common problems or complications that may develop in adulthood include:

Abnormal heart rhythms (arrhythmias). Heart rhythm problems (arrhythmias) occur when the electrical impulses in your heart that coordinate your heartbeats don't function properly, causing your heart to beat too fast, too slow or irregularly. Heart rhythm problems are common in people who have congenital heart disease. This can be because your heart defect itself interferes with the normal electrical impulses, or because previous corrective surgery left scar tissue that can cause arrhythmias. In some people, these arrhythmias can become severe, even causing sudden cardiac death if not properly treated. The treatment of arrhythmias has improved in recent years, so it's important you seek appropriate follow-up care.
Heart infections (endocarditis). The inside of your heart contains four chambers and four valves, which are lined by a thin membrane called the endocardium. Endocarditis is an infection of this inner lining. Some heart defects interrupt the smooth flow of blood in your heart, making it easier for bacteria to gather. Endocarditis typically occurs when bacteria or other germs from another part of your body, such as your mouth, enter your bloodstream and lodge in your heart. Left untreated, endocarditis can damage or destroy your heart valves or trigger a stroke. The consequences can be life-threatening. Your doctor may prescribe antibiotics to lower your risk of developing endocarditis.
Stroke. Stroke occurs when the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. Within a few minutes, brain cells begin to die. Some congenital heart defects increase your risk of stroke due to an abnormal connection in the heart allowing a blood clot from a vein to pass through your heart and travel to your brain. Certain heart arrhythmias can also increase your chance of blood clot formation leading to a stroke.
Heart failure. Heart failure, also known as congestive heart failure (CHF), means your heart can't pump enough blood to meet your body's needs. Some types of congenital heart disease can lead to heart failure. Over time, conditions such as coronary artery disease or high blood pressure gradually sap your heart of its strength, leaving it too weak or too stiff to fill and pump efficiently. Medications can improve the signs and symptoms of chronic heart failure and lead to improved survival. Lifestyle changes such as exercising, reducing salt intake, managing stress, treating depression and especially losing excess weight also can help prevent fluid buildup and improve your quality of life.
Pulmonary hypertension. This is a type of high blood pressure that only affects the arteries in the lungs. Some congenital heart defects can cause more blood to flow to the lungs, increasing pressure. As the pressure builds, your heart's lower right chamber (right ventricle) must work harder to pump blood through your lungs, eventually causing the heart muscle to weaken and sometimes to fail completely. If this problem isn't caught early, permanent lung artery damage can occur and result in a condition known as Eisenmenger's syndrome.
Heart valve problems. In some types of congenital heart disease, the heart valves are abnormal. Some heart defects may be minor early in life but cause problems in adulthood. In other cases a valve that has been repaired or replaced in childhood may require further surgery as an adult. Other types of surgical or catheter-based treatments performed in childhood also may require repeat procedures later in life.

Congenital heart disease treatment as an adult

There's a wide variation in the types and severity of congenital heart disease. Your doctor may suggest a treatment to attempt to correct the heart defect itself, or treat complications caused by the defect.

Relatively minor heart defects may require only periodic checkups with your doctor. Other types of congenital heart disease can worsen in adulthood, even if corrective surgery was done while you were a child. In these cases, medication or repeat surgery may be needed. Some procedures can now be done less invasively with the use of catheters. If you do have surgery or other forms of treatment, you'll still need long-term follow-up care or monitoring.

Congenital heart disease and pregnancy

Women with congenital heart disease who wish to become pregnant should talk with their doctors before becoming pregnant. They should discuss possible risks, as well as any special care they might need during pregnancy. Most women with congenital heart disease have normal pregnancies.

It's important for men and women who conceive to know that if they have congenital heart disease, there's an increased risk of passing on some form of congenital heart disease to their children. Your doctor may suggest genetic counseling to help you predict the risk of passing on inherited forms of congenital heart disease.

Taking care of yourself if you have congenital heart disease

One important thing to do if you're an adult with congenital heart disease is to become educated about your condition. Topics you should become familiar with include:

The name and details of your heart condition and its past treatment
How often you should be seen for follow-up care
Information about your medications and their side effects
How to prevent heart infections (endocarditis)
Exercise guidelines and any work restrictions
Birth control and family planning information
Health insurance information and coverage options
Dental care information, including whether you need antibiotics before dental procedures
Symptoms of your congenital heart disease and when you should contact your doctor

Each person with congenital heart disease has a different set of risks and concerns, so it's hard to generalize what's best for you. This is why it's so important to have regular communication with your doctor to discuss self-care options, including what activities you can do safely or what you should avoid. Thousands of adults with congenital heart disease lead full, long and productive lives. But it's important not to ignore your condition. Become informed about your disease; the more you know, the better you'll do.

RBC count

2008-02-05T06:27:00.000-08:00

lternative Names Erythrocyte count; Red blood cell count

Definition

An RBC count is a blood test that tells how many red blood cells (RBCs) you have.

RBCs contain hemoglobin, which carries oxygen. How much oxygen your body tissues get depends on how many RBCs you have and how well they work.

How the Test is Performed

Blood is drawn from a vein, usually on the inside of the elbow or the back of the hand. The puncture site is cleaned with antiseptic, and an elastic band is placed around the upper arm to apply pressure and restrict blood flow through the vein. This causes veins below the band to fill with blood.

A needle is inserted into the vein, and the blood is collected in an air-tight vial or a syringe. During the procedure, the band is removed to restore blood flow. Once the blood has been collected, the needle is removed, and the puncture site is covered to stop any bleeding.

For an infant or young child:

The area is cleansed with antiseptic and punctured with a sharp needle or a lancet. The blood may be collected in a pipette (small glass tube), on a slide, onto a test strip, or into a small container. Cotton or a bandage may be applied to the puncture site if there is any continued bleeding.

How to Prepare for the Test

No special preparation is necessary for adults.

How the Test Will Feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Veins and arteries vary in size from one patient to another and from one side of the body to the other. Obtaining a blood sample from some people may be more difficult than from others.

Why the Test is Performed

This test can help diagnose anemia and other conditions affecting red blood cells.

The RBC count is almost always part of the CBC (complete blood count) test.

Normal Results
Normal results vary, but in general the range is as follows:

Male: 4.7 to 6.1 million cells per microliter (cells/mcL)
Female: 4.2 to 5.4 million cells/mcL

What Abnormal Results Mean

Damaged RBCs do not live as long as normal. Injury inside the blood vessels, such as that caused by artificial heart valves or peripheral blood vessel disease, can damage RBCs.

Higher-than-normal numbers of RBCs may be due to:

Congenital heart disease
Cor pulmonale
Dehydration (such as from severe diarrhea)
Pulmonary fibrosis
Polycythemia vera

Lower-than-normal numbers of RBCs may be due to:

Anemia (various types)
Bone marrow failure (for example, from radiation, toxin, or tumor)
Erythropoietin deficiency (secondary to kidney disease)
Hemolysis (RBC destruction) from transfusion reaction
Hemorrhage (bleeding)
Leukemia
Malnutrition
Multiple myeloma
Nutritional deficiencies of:
- Iron
- Copper
- Folate
- Vitamin B-12
- Vitamin B-6
Overhydration

Additional conditions under which the test may be performed:

Alport syndrome
Drug-induced immune hemolytic anemia
Hemolytic anemia due to G6PD deficiency
Hereditary anemias, such as thalassemia
Idiopathic autoimmune hemolytic anemia
Immune hemolytic anemia
Macroglobulinemia of Waldenstrom
Paroxysmal nocturnal hemoglobinuria (PNH)
Primary myelofibrosis
Renal cell carcinoma

Risks

Excessive bleeding
Fainting or feeling light-headed
Hematoma (blood accumulating under the skin)
Infection (a slight risk any time the skin is broken)
Multiple punctures to locate veins

Considerations

Pregnancy can cause a decrease in RBCs.

Your RBC count will increase for several weeks when you move to a higher altitude. Dehydration also increases the RBC count.

Drugs can increase the RBC count include:

Gentamicin
Methyldopa

Drugs that can decrease the RBC count include:

Chloramphenicol
Hydantoins
Quinidine

Stroke

2008-02-04T09:57:00.000-08:00

Stroke

Introduction

A stroke occurs when the blood supply to a part of your brain is interrupted or severely reduced, depriving brain tissue of oxygen and nutrients. Within a few minutes, brain cells begin to die.

Stroke is a medical emergency. Prompt treatment of a stroke could mean the difference between life and death. Early treatment can also minimize damage to your brain and potential disability.

In the United States, stroke is a leading cause of adult disability and the third-leading cause of death; only heart disease and cancer cause more deaths annually.

The good news is that many fewer Americans now die of strokes than was the case 20 or 30 years ago. Improvement in the control of major risk factors for stroke — smoking, high blood pressure and high cholesterol — is likely responsible for the decline.

Signs and symptoms

Knowing the signs and symptoms of a stroke may make it possible for you or someone you know to get prompt treatment. The signs and symptoms of stroke usually occur suddenly; frequently there's more than one. Signs and symptoms include:

Sudden numbness, weakness, or paralysis of your face, arm or leg — usually on one side of your body
Sudden difficulty speaking or understanding speech (aphasia)
Sudden blurred, double or decreased vision
Sudden dizziness, loss of balance or loss of coordination
A sudden, severe "bolt out of the blue" headache or an unusual headache, which may be accompanied by a stiff neck, facial pain, pain between your eyes, vomiting or altered consciousness
Confusion, or problems with memory, spatial orientation or perception

For most people, a stroke gives no warning. But one possible sign of an impending stroke is a transient ischemic attack (TIA). A TIA is a temporary interruption of blood flow to a part of your brain.

The signs and symptoms of TIA are the same as for a stroke, but they last for a shorter period — several minutes to 24 hours — and then disappear, without leaving apparent permanent effects. You may have more than one TIA, and the recurrent signs and symptoms may be similar or different.

A TIA indicates a serious underlying risk that a full-blown stroke may follow. People who have had a TIA are much more likely to have a stroke as are those who haven't had a TIA.

Causes

CLICK TO ENLARGE

Ischemic stroke

A stroke is sometimes called a brain attack. The problem is with the amount of blood in your brain. The cause of one type of stroke — ischemic stroke — is too little blood in the brain. The cause of the other main type of stroke — hemorrhagic stroke — is too much blood within the skull.

Ischemic stroke
About 80 percent of strokes are ischemic strokes. They occur when blood clots or other particles block arteries to your brain and cause severely reduced blood flow (ischemia). This deprives your brain cells of oxygen and nutrients, and cells may begin to die within minutes. The most common ischemic strokes are:

Thrombotic stroke. This type of stroke occurs when a blood clot (thrombus) forms in one of the arteries that supply blood to your brain. A clot usually forms in areas damaged by atherosclerosis — a disease in which the arteries are clogged by an accumulation of cholesterol-containing fatty deposits (plaques). This process can occur within one of the two carotid (kuh-ROT-id) arteries of your neck that carry blood to your brain, as well as in other arteries. An ischemic stroke may also be caused by plaques that completely clog or markedly narrow an artery. This narrowing is called stenosis.
Embolic stroke. An embolic stroke occurs when a blood clot or other particle forms in a blood vessel away from your brain — commonly in your heart — and is swept through your bloodstream to lodge in narrower brain arteries. This type of blood clot is called an embolus. It's often caused by irregular beating in the heart's two upper chambers (atrial fibrillation). This abnormal heart rhythm can lead to poor blood flow and the formation of a blood clot.

Hemorrhagic stroke
"Hemorrhage" is the medical word for bleeding. Hemorrhagic stroke occurs when a blood vessel in your brain leaks or ruptures. Hemorrhages can result from a number of conditions that affect your blood vessels, including uncontrolled high blood pressure (hypertension) and weak spots in your blood vessel walls (aneurysms). A less common cause of hemorrhage is the rupture of an arteriovenous malformation (AVM) — a malformed tangle of thin-walled blood vessels, present at birth. There are two types of hemorrhagic stroke:

Intracerebral hemorrhage. In this type of stroke, a blood vessel in the brain bursts and spills into the surrounding brain tissue, damaging cells. Brain cells beyond the leak are deprived of blood and are also damaged. High blood pressure is the most common cause of this type of hemorrhagic stroke. High blood pressure can cause small arteries inside your brain to become brittle and susceptible to cracking and rupture.
Subarachnoid hemorrhage. In this type of stroke, bleeding starts in a large artery on or near the membrane surrounding the brain and spills into the space between the surface of your brain and your skull. A subarachnoid hemorrhage is often signaled by a sudden, severe "thunderclap" headache. This type of stroke is commonly caused by the rupture of an aneurysm, which can develop with age or result from a genetic predisposition. After a subarachnoid hemorrhage, vessels may go into vasospasm, a condition in which arteries near the hemorrhage constrict erratically, causing brain cell damage by further restricting or blocking blood flow to portions of the brain.

Risk factors

Many factors can increase your risk of a stroke. A number of these factors can also increase your chances of having a heart attack. They include:

Family history. Your risk of stroke is slightly greater if one of your parents or a brother or sister has had a stroke or TIA.
Age. Your risk of stroke increases as you get older.
Sex. Stroke affects men and women about equally, but women are more likely to die of stroke than are men.
Race. Blacks are at greater risk of stroke than are people of other races. This is partly due to a higher prevalence of high blood pressure and diabetes.
High blood pressure (hypertension). High blood pressure is a risk factor for both ischemic and hemorrhagic strokes. It can weaken and damage blood vessels in and around your brain, leaving them vulnerable to atherosclerosis and hemorrhage.
Undesirable levels of blood cholesterol. High levels of low-density lipoprotein (LDL) cholesterol, the "bad" cholesterol, may increase your risk of atherosclerosis. In excess, LDLs and other materials build up on the lining of artery walls, where they may harden into plaques. High levels of triglycerides, a blood fat, also may increase your risk of atherosclerosis. In contrast, high levels of high-density lipoprotein (HDL) cholesterol, the "good" cholesterol, reduce your risk of atherosclerosis by escorting cholesterol out of your body through your liver.
Cigarette smoking. Smokers have a much higher risk of stroke than do nonsmokers. Smoking contributes to plaques in your arteries. Nicotine makes your heart work harder by increasing your heart rate and blood pressure. The carbon monoxide in cigarette smoke replaces oxygen in your blood, decreasing the amount of oxygen delivered to the walls of your arteries and your tissues, including the tissues in your brain.
Diabetes. Diabetes is a major risk factor for stroke. When you have diabetes, your body not only can't handle glucose appropriately, but it also can't process fats efficiently, and you're at greater risk of high blood pressure. These diabetes-related effects increase your risk of developing atherosclerosis. Diabetes also interferes with your body's ability to break down blood clots, increasing your risk of ischemic stroke.
Obesity. Being overweight increases your chance of developing high blood pressure, heart disease, atherosclerosis and diabetes — all of which increase your risk of a stroke.
Cardiovascular disease. Several cardiovascular diseases can increase your risk of a stroke, including congestive heart failure, a previous heart attack, an infection of a heart valve (endocarditis), a particular type of abnormal heart rhythm (atrial fibrillation), aortic or mitral valve disease, valve replacement, or a hole in the upper chambers of the heart known as patent foramen ovale. Atrial fibrillation is the most common condition associated with strokes caused by embolic clots. In addition, atherosclerosis in blood vessels near your heart may indicate that you have atherosclerosis in other blood vessels — including those in and around your brain.
Previous stroke or TIA. If you've already had a stroke, your risk of having another one increases. In addition, people who have had a TIA are much more likely to have a stroke as are those who haven't had a TIA.
Elevated homocysteine level. This amino acid, a building block of proteins, occurs naturally in your blood. But people with elevated levels of homocysteine have a higher risk of heart and blood vessel damage.
Use of birth control pills and hormone therapy. The risk of stroke is higher among women who take birth control pills, especially among smokers and those older than 35. However, today's low-dose pills carry a much lower risk than their earlier counterparts. Hormone therapy for menopause also carries a slightly increased risk of stroke.

Other factors that can increase your risk of stroke include heavy or binge drinking, the use of illicit drugs such as cocaine, and uncontrolled stress.

When to seek medical advice

If you notice any signs or symptoms of a stroke or TIA, get medical help right away. A TIA may seem like a passing event. But it is an important warning sign — and a chance to take steps that may prevent a stroke.

If someone appears to be having a stroke, watch the person carefully while waiting for an ambulance. You may need to take additional actions in the following situations:

If breathing ceases, begin resuscitation.
If vomiting occurs, turn the person's head to the side. This can prevent choking.
Don't let the person eat or drink anything.

Every minute counts when it comes to treating a stroke or TIA. Don't wait to see if the signs and symptoms go away. The longer a stroke goes untreated, the greater the damage and potential disability. The success of most treatments depends on how soon a person is seen by a doctor in a hospital emergency room after signs and symptoms begin.

Screening and diagnosis

If you've had a previous stroke or TIA or think you're at risk of stroke, talk with your doctor about screening and diagnostic tests.

Before treating a stroke, your doctor must diagnose the type of stroke and its location. Other possible causes of your symptoms, such as a tumor, also need to be excluded.

The following are most often used as screening tools to determine your risk, but they may also be used as diagnostic tools if you're having a stroke:

Physical examination and tests. Your doctor may check for risk factors of stroke, including high blood pressure, high cholesterol levels, diabetes and elevated levels of the amino acid homocysteine. Your doctor may also use a stethoscope to listen for a whooshing sound (bruit) over your arteries that may indicate atherosclerosis.
Carotid ultrasonography. In this procedure, a wand-like device (transducer) sends high-frequency sound waves into your neck. The sound waves pass through tissue and then return, creating on-screen images that delineate any narrowing or clotting in your carotid arteries.
Arteriography. This procedure gives a view of arteries in your brain not normally seen in X-rays. Your doctor inserts a thin, flexible tube (catheter) through a small incision, usually in your groin. The catheter is manipulated through your major arteries and into your carotid or vertebral artery. Then your doctor injects a dye through the catheter to provide X-ray images of your arteries.
Computerized tomography (CT). In computerized tomographic angiography (CTA), a dye is injected into your vein and X-ray beams create a three-dimensional image of the blood vessels in your neck and brain. Doctors use CTA to look for aneurysms or arteriovenous malformations and to evaluate arteries for narrowing. CT scanning, which is done without dye, can provide images of your brain and show hemorrhages, but without as much detailed information about the blood vessels.
Magnetic resonance imaging (MRI). Using a strong magnetic field, an MRI can generate a three-dimensional view of your brain. This test is sensitive for detecting an area of brain tissue damaged by an ischemic stroke. Magnetic resonance angiography (MRA) uses this magnetic field and a dye injected into your veins to evaluate arteries in your neck and brain.
Echocardiography. Your doctor can use this ultrasound technology to compose images of your heart. He or she may also use transesophageal echocardiography (TEE). During this procedure, a flexible probe with a transducer built into it is placed in your esophagus — the tube that connects the back of your mouth to your stomach. Because your esophagus is directly behind your heart, very clear, detailed ultrasound images can be created, allowing a better view of some things, such as blood clots, that might not be seen clearly in a traditional echocardiography exam.

Treatment

Getting prompt medical treatment for stroke is of utmost importance. Treatment itself depends on the type of stroke.

Ischemic stroke
To treat an ischemic stroke, doctors must remove any obstruction and restore blood flow to your brain.

Emergency treatment. Therapy with clot-busting drugs must start within three hours. Quick treatment not only improves your chances of survival, but may also reduce the amount of disability resulting from the stroke.

Injection of a clot-busting (thrombolytic) drug — such as a tissue plasminogen activator (TPA) — into your veins to dissolve a blood clot may be more effective in increasing your chances of a full recovery, compared with other treatment methods. Currently, though, only a small proportion of Americans who have had a stroke receive thrombolytic therapy. Reasons for this include:

A limited time window. Three hours has long been considered the window within which clot-busting drugs should be administered intravenously. Whether people can still gain some benefit from receiving clot-busting drugs beyond three hours is uncertain. After too much time has passed, the risks of bleeding or other complications from this type of therapy begin to outweigh the potential benefits.
A limited group of people who benefit from this therapy. TPA-type therapy doesn't treat hemorrhagic stroke. In fact, it may dramatically worsen a hemorrhagic stroke. Also, not everyone who has had an ischemic stroke is an ideal candidate for thrombolytic therapy. The ability of TPA-type agents to dissolve blood clots carries with it a risk of brain hemorrhage and bleeding elsewhere. With the diagnosis of an acute stroke, you and your doctor can work together to weigh the risks versus benefits of thrombolytic therapy in your individual case. Your doctor may not give you clot-busting medications if your blood pressure isn't controllable at the time when the TPA is being considered.

Surgical and other procedures. Your doctor may recommend a procedure to open up an artery that's moderately to severely narrowed by plaques. This may include:

Carotid endarterectomy. Your surgeon makes an incision in your neck to expose your carotid artery. The artery is opened, the plaques are removed, and your surgeon closes the artery. In people with marked blockages in the carotid artery who are candidates for the surgery, the procedure may reduce the risk of ischemic stroke. However, in addition to the usual risks associated with any surgery, a carotid endarterectomy itself can also trigger a stroke or heart attack by releasing a blood clot or fatty debris, although surgeons now place filters (distal protection devices) at strategic points in your bloodstream to "catch" any material that may break free during the procedure.
Angioplasty. Used less commonly than carotid endarterectomy, angioplasty can widen the inside of an artery leading to your brain, usually the carotid artery. In this procedure, a balloon-tipped catheter is maneuvered into the obstructed area of your artery. The balloon is inflated, compressing the plaques against your artery walls. A metallic mesh tube (stent) is usually left in the artery to prevent recurrent narrowing. Distal protection devices also may be used with angioplasty.
Other techniques. Doctors are also exploring new ways to remove clots. In a catheter embolectomy, a catheter is threaded into one of the arteries that lead to the brain and used to remove clots. You may also receive thrombolytic drugs directly into these arteries, via a catheter.

Preventive medications. If you've had an ischemic stroke, it's important to determine why the stroke occurred and to prevent another. Your doctor may recommend medications to help reduce your risk of having a TIA or stroke. These include:

Anti-platelet drugs. Platelets are cells in your blood that initiate clots. Anti-platelet drugs make your platelets less sticky and less likely to clot. The most frequently used anti-platelet medication is aspirin. Your doctor may also consider prescribing Aggrenox, a combination of low-dose aspirin and the anti-platelet drug dipyridamole, to reduce blood clotting. If aspirin doesn't prevent your TIA or stroke or if you can't take aspirin, your doctor may instead prescribe an anti-platelet drug such as clopidogrel (Plavix) or ticlopidine (Ticlid).
Anticoagulants. These drugs include heparin and warfarin (Coumadin). They affect the clotting mechanism in a different manner than do anti-platelet medications. Heparin is fast acting and is used over the short term in the hospital. Slower acting warfarin is used over a longer term. These drugs have a profound effect on blood clotting and require that you work with your doctor to monitor them closely. Your doctor may prescribe these drugs if you have certain blood-clotting disorders, certain arterial abnormalities, an abnormal heart rhythm, such as atrial fibrillation, or other heart problems.

Hemorrhagic stroke
Surgery may be used to treat a hemorrhagic stroke or prevent another one. The most common procedures — aneurysm clipping and arteriovenous malformation (AVM) removal — carry some risks. Your doctor may recommend one of these procedures if you're at high risk of spontaneous aneurysm or AVM rupture:

Aneurysm clipping. A tiny clamp is placed at the base of the aneurysm, isolating it from the circulation of the artery to which it's attached. This can keep the aneurysm from bursting, or it can prevent re-bleeding of an aneurysm that has recently hemorrhaged.
Coiling (aneurysm embolization). In an embolization procedure, a catheter is maneuvered into the aneurysm. A tiny platinum coil is pushed through the catheter and positioned inside the aneurysm. The coil fills the aneurysm, causing clotting and sealing the aneurysm off from connecting arteries.
Surgical AVM removal. It's not always possible to remove an AVM if it's too large or if it's located deep within the brain. Surgical removal of a smaller AVM from a more accessible portion of the brain, though, can eliminate the risk of rupture, lowering the overall risk of hemorrhagic stroke. Other treatment options for AVMs include focused radiation or embolization, in which the small arteries supplying the blood to the AVM are blocked, shrinking the AVM.

Recovery and rehabilitation
Stroke survivors who can go home to a healthy spouse or other companion are more likely to become independent and productive again. Encouragement and early treatment are important.

Recovery and rehabilitation depend on the area of the brain involved and the amount of tissue damaged. Harm to the right side of the brain may impair movement and sensation on the left side of the body. Damage to brain tissue on the left side may affect movement on the right side; this damage may also cause speech and language disorders. In addition, people who've had a stroke may have problems with breathing, swallowing, balancing and hearing, and loss of vision and bladder or bowel function.

Because numerous impairments may be involved, rehabilitation is facilitated by a diverse team, which may include a:

Rehabilitation doctor (physiatrist)
Nurse
Dietitian
Physical therapist
Occupational therapist
Recreational therapist
Speech therapist
Social worker
Psychologist or psychiatrist
Chaplain

The goal of rehabilitation is to help you recover as much of your independence and functioning as possible. Much of rehabilitation involves relearning skills you may have lost, such as walking or communicating.

With advances in research and brain-imaging techniques, doctors are gaining a new understanding of how brain systems adapt after stroke to regain function (brain plasticity). Research suggests that normal brain cells are highly adaptable and can undergo changes in function and shape that allow them to take on the functions of nearby damaged cells. As a result, rehabilitation efforts are being geared toward retraining unaffected brain tissue to compensate for the lost functions of damaged tissue.

Prevention

Knowing your risk factors and living healthfully are the best steps you can take to prevent a stroke. In general, a healthy lifestyle means that you:

Control high blood pressure (hypertension). One of the most important things you can do to reduce your stroke risk is to keep your blood pressure under control. If you've had a stroke, lowering your blood pressure can help prevent a subsequent transient ischemic attack or stroke. Exercising, managing stress, maintaining a healthy weight, and limiting sodium and alcohol intake are all ways to keep hypertension in check. In addition to recommendations for lifestyle changes, your doctor may prescribe medications to treat hypertension, such as diuretics, angiotensin-converting enzyme (ACE) inhibitors and angiotensin receptor blockers.
Lower your cholesterol and saturated fat intake. Eating less cholesterol and fat, especially saturated fat, may reduce the plaques in your arteries. If you can't control your cholesterol through dietary changes alone, your doctor may prescribe a cholesterol-lowering medication.
Don't smoke. Quitting smoking reduces your risk of stroke. Several years after quitting, a former smoker's risk of stroke is the same as that of a nonsmoker.
Control diabetes. You can manage diabetes with diet, exercise, weight control and medication. Strict control of your blood sugar may reduce damage to your brain if you do have a stroke.
Maintain a healthy weight. Being overweight contributes to other risk factors for stroke, such as high blood pressure, cardiovascular disease and diabetes. Weight loss of as little as 10 pounds may lower your blood pressure and improve your cholesterol levels.
Exercise regularly. Aerobic exercise reduces your risk of stroke in many ways. Exercise can lower your blood pressure, increase your level of HDL cholesterol, and improve the overall health of your blood vessels and heart. It also helps you lose weight, control diabetes and reduce stress. Gradually work up to 30 minutes of activity — such as walking, jogging, swimming or bicycling — on most, if not all, days of the week.
Manage stress. Stress can cause a temporary spike in your blood pressure — a risk factor for brain hemorrhage — or long-lasting hypertension. It can also increase your blood's tendency to clot, which may elevate your risk of ischemic stroke. Simplifying your life, exercising and using relaxation techniques are all approaches that you can learn to reduce stress.
Drink alcohol in moderation, if at all. Alcohol can be both a risk factor and a preventive measure for stroke. Binge drinking and heavy alcohol consumption increase your risk of high blood pressure and of ischemic and hemorrhagic strokes. However, drinking small to moderate amounts of alcohol can increase your HDL cholesterol and decrease your blood's clotting tendency. Both factors can contribute to a reduced risk of ischemic stroke.
Don't use illicit drugs. Many street drugs, such as cocaine and crack cocaine, are established risk factors for a TIA or a stroke.

Follow a healthy diet
In addition, eat healthy foods. A brain-healthy diet should include:

Five or more daily servings of fruits and vegetables, which contain nutrients such as potassium, folate and antioxidants that may protect you against stroke.
Foods rich in soluble fiber, such as oatmeal and beans.
Foods rich in calcium, a mineral found to reduce stroke risk.
Soy products, such as tempeh, miso, tofu and soy milk, which can reduce your LDL cholesterol and raise your HDL cholesterol level.
Foods rich in omega-3 fatty acids, including cold-water fish, such as salmon, mackerel and tuna. However, pregnant women and women who plan to become pregnant in the next several years should limit their weekly intake of cold-water fish because of the potential for mercury contamination.

You obviously can't change some risk factors for a stroke — family history, age, sex and race. But knowing you're at risk can motivate you to change your lifestyle to reduce other risks. First-time heart attacks and strokes are often fatal or disabling; therefore, prevention is critical. The American Heart Association (AHA) recommends:

Early risk factor screening. The AHA recommends that all people, beginning at age 20, undergo risk factor screening that includes recording blood pressure, body mass index, waist circumference and pulse at least every two years, and cholesterol and glucose testing at least every five years.
Risk estimation. The AHA recommends that doctors estimate each person's percentage risk of developing cardiovascular disease within the next 10 years. The estimate would be based on the risk factor screening. The AHA recommends estimation of risk every five years for people age 40 or older, or for anyone with two or more risk factors.

Coping skills

Recovering from a stroke can be mentally exhausting. In addition to the various physical side effects, feelings of helplessness, frustration, depression and apathy aren't unusual. Diminished sex drive and mood changes are also common.

The rate and amount of recovery after stroke is highly individualized. Much depends on the extent of damage to your brain, and the intensity and duration of the therapy you receive. But your recovery also is likely to be influenced by your personality, life experiences and coping styles. Your own motivation to recover is a key factor in obtaining an optimal level of rehabilitation.

If someone close to you has had a stroke, you can play an important role in the recovery process by offering companionship and support. Here are some tips to help you communicate with someone whose speech has been affected by a stroke:

Stay in touch. Your friend or family member needs you but might not be able to tell you so. Make an effort to be there.
Keep conversation at an adult level. Address stroke survivors directly and don't talk down to them. Treat them just as you did before the stroke. Because someone has had a stroke doesn't mean he or she can't think anymore.
Use a normal tone of voice. Unless there's a hearing loss, you don't need to speak more loudly than usual.
Speak at a comfortable pace. Allow time for your words to be processed. Try to talk about only one topic at a time.
Avoid distractions. Reduce background noise and distractions from TVs, radios and physical activities.
Talk one-on-one. A stroke survivor may understand best when the conversation includes fewer people.
Keep caregivers in mind. They need support and friendship, too. Include them in your thoughts and plans.

Although stroke-related disabilities can be permanent, many people lead active lives after a stroke. Many are able to resume everyday life and responsibilities.

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Medical animation of woman swallowing a pill

2008-02-03T02:18:00.002-08:00

What are feeding and swallowing disorders?

Feeding disorders include problems gathering food and getting ready to suck, chew, or swallow it. For example, a child who cannot pick up food and get it to her mouth or cannot completely close her lips to keep food from falling out of her mouth may have a feeding disorder.

Swallowing disorders, also called dysphagia (dis-FAY-juh), can occur at different stages in the swallowing process:

* Oral phase–sucking, chewing, and moving food or liquid into the throat

* Pharyngeal phase–starting the swallow, squeezing food down the throat, and closing off the airway to prevent food or liquid from entering the airway (aspiration) or to prevent choking

* Esophageal phase–relaxing and tightening the openings at the top and bottom of the feeding tube in the throat (esophagus) and squeezing food through the esophagus into the stomach

Return to Top
What are some signs or symptoms of feeding and swallowing disorders in children?

Children with feeding and swallowing problems have a wide variety of symptoms. Not all signs and symptoms are present in every child.

The following are signs and symptoms of feeding and swallowing problems in very young children:

* arching or stiffening of the body during feeding
* irritability or lack of alertness during feeding
* refusing food or liquid
* failure to accept different textures of food (e.g., only pureed foods or crunchy cereals)
* long feeding times (e.g., more than 30 minutes)
* difficulty chewing
* difficulty breast feeding
* coughing or gagging during meals
* excessive drooling or food/liquid coming out of the mouth or nose
* difficulty coordinating breathing with eating and drinking
* increased stuffiness during meals
* gurgly, hoarse, or breathy voice quality
* frequent spitting up or vomiting
* recurring pneumonia or respiratory infections
* less than normal weight gain or growth

As a result, children may be at risk for:

* dehydration or poor nutrition
* aspiration (food or liquid entering the airway) or penetration
* pneumonia or repeated upper respiratory infections that can lead to chronic lung disease
* embarrassment or isolation in social situations involving eating

Return to Top
How are feeding and swallowing disorders diagnosed?

If you suspect that your child is having difficulty eating, contact your pediatrician right away. Your pediatrician will examine your child and address any medical reasons for the feeding difficulties, including the presence of reflux or metabolic disorders. A speech-language pathologist (SLP) who specializes in treating children with feeding and swallowing disorders can evaluate your child and will:

* ask questions about your child's medical history, development, and symptoms
* look at the strength and movement of the muscles involved in swallowing
* observe feeding to see your child' s posture, behavior, and oral movements during eating and drinking
* perform special tests, if necessary, to evaluate swallowing, such as:
o modified barium swallow–child eats or drinks food or liquid with barium in it, and then the swallowing process is viewed on an X-ray.
o endoscopic assessment–a lighted scope is inserted through the nose, and the child's swallow can be observed on a screen.

The SLP may work as part of a feeding team. Other team members may include:

* an occupational therapist
* a physical therapist
* a physician or nurse
* a dietitian or nutritionist
* a developmental specialist

Your child's posture, self-feeding abilities, medical status, and nutritional intake will be examined by the team. The team will then make recommendations on how to improve your child's feeding and swallowing.

To contact a speech-language pathologist, visit ASHA's Find a Professional.

What treatments are available for children with feeding and swallowing disorders?

Treatment varies greatly depending on the cause and symptoms of the swallowing problem.

Based on the results of the feeding and swallowing evaluation, the SLP or feeding team may recommend any of the following:

* medical intervention (e.g., medicine for reflux)
* direct feeding therapy designed to meet individual needs
* nutritional changes (e.g., different foods, adding calories to food)
* increasing acceptance of new foods or textures
* food temperature and texture changes
* postural or positioning changes (e.g., different seating)
* behavior management techniques
* referral to other professionals, such as a psychologist or dentist

If feeding therapy with an SLP is recommended, the focus on intervention may include the following:

* making the muscles of the mouth stronger
* increasing tongue movement
* improving chewing
* increasing acceptance of different foods and liquids
* improving sucking and/or drinking ability
* coordinating the suck-swallow-breath pattern (for infants)
* altering food textures and liquid thickness to ensure safe swallowing

After the evaluation, family members or caregivers can

* ask questions to understand problems in feeding and swallowing
* make sure they understand the treatment plan
* go to treatment plans
* follow recommended techniques at home and school
* talk with everyone who works with the child about the feeding and swallowing issues and treatment plan
* provide feedback to the SLP or feeding team about what is or is not working at home

Medical animation of woman swallowing a pill

2008-02-03T02:18:00.001-08:00

What are feeding and swallowing disorders?

Feeding disorders include problems gathering food and getting ready to suck, chew, or swallow it. For example, a child who cannot pick up food and get it to her mouth or cannot completely close her lips to keep food from falling out of her mouth may have a feeding disorder.

Swallowing disorders, also called dysphagia (dis-FAY-juh), can occur at different stages in the swallowing process:

* Oral phase–sucking, chewing, and moving food or liquid into the throat

* Pharyngeal phase–starting the swallow, squeezing food down the throat, and closing off the airway to prevent food or liquid from entering the airway (aspiration) or to prevent choking

* Esophageal phase–relaxing and tightening the openings at the top and bottom of the feeding tube in the throat (esophagus) and squeezing food through the esophagus into the stomach

Return to Top
What are some signs or symptoms of feeding and swallowing disorders in children?

Children with feeding and swallowing problems have a wide variety of symptoms. Not all signs and symptoms are present in every child.

The following are signs and symptoms of feeding and swallowing problems in very young children:

* arching or stiffening of the body during feeding
* irritability or lack of alertness during feeding
* refusing food or liquid
* failure to accept different textures of food (e.g., only pureed foods or crunchy cereals)
* long feeding times (e.g., more than 30 minutes)
* difficulty chewing
* difficulty breast feeding
* coughing or gagging during meals
* excessive drooling or food/liquid coming out of the mouth or nose
* difficulty coordinating breathing with eating and drinking
* increased stuffiness during meals
* gurgly, hoarse, or breathy voice quality
* frequent spitting up or vomiting
* recurring pneumonia or respiratory infections
* less than normal weight gain or growth

As a result, children may be at risk for:

* dehydration or poor nutrition
* aspiration (food or liquid entering the airway) or penetration
* pneumonia or repeated upper respiratory infections that can lead to chronic lung disease
* embarrassment or isolation in social situations involving eating

Return to Top
How are feeding and swallowing disorders diagnosed?

If you suspect that your child is having difficulty eating, contact your pediatrician right away. Your pediatrician will examine your child and address any medical reasons for the feeding difficulties, including the presence of reflux or metabolic disorders. A speech-language pathologist (SLP) who specializes in treating children with feeding and swallowing disorders can evaluate your child and will:

* ask questions about your child's medical history, development, and symptoms
* look at the strength and movement of the muscles involved in swallowing
* observe feeding to see your child' s posture, behavior, and oral movements during eating and drinking
* perform special tests, if necessary, to evaluate swallowing, such as:
o modified barium swallow–child eats or drinks food or liquid with barium in it, and then the swallowing process is viewed on an X-ray.
o endoscopic assessment–a lighted scope is inserted through the nose, and the child's swallow can be observed on a screen.

The SLP may work as part of a feeding team. Other team members may include:

* an occupational therapist
* a physical therapist
* a physician or nurse
* a dietitian or nutritionist
* a developmental specialist

Your child's posture, self-feeding abilities, medical status, and nutritional intake will be examined by the team. The team will then make recommendations on how to improve your child's feeding and swallowing.

To contact a speech-language pathologist, visit ASHA's Find a Professional.

Return to Top
What treatments are available for children with feeding and swallowing disorders?

Treatment varies greatly depending on the cause and symptoms of the swallowing problem.

Based on the results of the feeding and swallowing evaluation, the SLP or feeding team may recommend any of the following:

* medical intervention (e.g., medicine for reflux)
* direct feeding therapy designed to meet individual needs
* nutritional changes (e.g., different foods, adding calories to food)
* increasing acceptance of new foods or textures
* food temperature and texture changes
* postural or positioning changes (e.g., different seating)
* behavior management techniques
* referral to other professionals, such as a psychologist or dentist

If feeding therapy with an SLP is recommended, the focus on intervention may include the following:

* making the muscles of the mouth stronger
* increasing tongue movement
* improving chewing
* increasing acceptance of different foods and liquids
* improving sucking and/or drinking ability
* coordinating the suck-swallow-breath pattern (for infants)
* altering food textures and liquid thickness to ensure safe swallowing

After the evaluation, family members or caregivers can

* ask questions to understand problems in feeding and swallowing
* make sure they understand the treatment plan
* go to treatment plans
* follow recommended techniques at home and school
* talk with everyone who works with the child about the feeding and swallowing issues and treatment plan
* provide feedback to the SLP or feeding team about what is or is not working at home

blood protein

2008-02-02T03:51:00.000-08:00

How is it used?
Total protein measurements can reflect nutritional status, kidney disease, liver disease, and many other conditions. If total protein is abnormal, further tests must be performed to identify which protein fraction is abnormal, so that a specific diagnosis can be made.

When is it ordered?
Total protein is ordered to provide general information about your nutritional status, such as when you have undergone a recent weight loss. It is also ordered along with several other tests to provide information if you have symptoms that suggest a liver or kidney disorder, or to investigate the cause of abnormal pooling of fluid in tissue (edema).

What does the test result mean?
NOTE: A standard reference range is not available for this test. Because reference values are dependent on many factors, including patient age, gender, sample population, and test method, numeric test results have different meanings in different labs. Your lab report should include the specific reference range for your test. Lab Tests Online strongly recommends that you discuss your test results with your doctor. For more information on reference ranges, please read Reference Ranges and What They Mean.

Low total protein levels can suggest a liver disorder, a kidney disorder, or a disorder in which protein is not digested or absorbed properly. Some laboratories also report the calculated ratio of albumin to globulins, termed the A/G ratio. Normally, there is a little more albumin than globulins, giving a normal A/G ratio of slightly over 1. Because disease states affect the relative changes in albumin and globulins in different ways, this may provide a clue to the physician as to the cause of the change in protein levels. A low A/G ratio may reflect overproduction of globulins (such as seen in multiple myeloma or autoimmune diseases) or underproduction of albumin (such as occurs with cirrhosis) or selective loss of albumin from the circulation (as occurs with nephrotic syndrome). A high A/G ratio suggests underproduction of immunoglobulins (as may be seen in some genetic deficiencies and in some leukemias). More specific tests, such as albumin, liver enzyme tests, and serum protein electrophoresis must be performed to make an accurate diagnosis.

Is there anything else I should know?
Prolonged application of a tourniquet during blood collection can result in a blood sample that has a higher protein concentration than the rest of the circulation. This will mean that the test result for total protein will be falsely elevated (higher than the actual concentration in the circulation). Drugs that may decrease protein levels include estrogens and oral contraceptives.

LASIK 3D Medical Animation

2008-02-01T01:02:00.000-08:00

LASIK Surgery Screening Guidelines For Patients

The Eye Surgery Education Council Medical Advisory Board: Chair, Roger F. Steinert, MD; Douglas D. Koch, MD; Stephen S. Lane, MD; R. Doyle Stulting, MD

I. Introduction

Laser in-situ keratomileusis, or LASIK, the most commonly performed type of laser surgery, is generally a safe and effective treatment for a wide range of common vision problems. Specifically, LASIK involves the use of a laser to permanently change the shape of the cornea, the clear covering of the front of the eye. LASIK is a quick and often painless procedure, and for the majority of patients, the surgery improves vision and reduces the need for corrective eyewear. However, as LASIK is a surgical procedure conducted on a delicate part of the eye, it is crucial that potential candidates are well educated on the benefits and risks of the procedure, understand the importance of a thorough screening by their physician, and maintain realistic expectations about the procedure’s outcome.
II. Patient Profiles:

Who is Right for Laser Eye Surgery? While many individuals are considered good candidates for LASIK, there are some who do not meet the general-ly accepted medical criteria to ensure a successful laser vision procedure. Individuals that are not deemed good candidates given today’s technology may be able to have the surgery in the future, as technology advances and new techniques are refined. Anyone considering laser eye surgery must have a thorough examination by an ophthalmologist that will help determine, in consulta-tion with the patient, whether or not the LASIK proce-dure is right for them. Based on various conditions and circumstances, all LASIK candidates will fall into one of the following three broad categories.

The Ideal LASIK Candidate

The ideal candidate includes those who:

• Are over 18 years of age and have had a stable glasses or contact lens prescription for at least two years.

• Have sufficient corneal thickness (the cornea is the trans-parent front part of the eye). A LASIK patient should have a cornea that is thick enough to allow the surgeon to safe-ly create a clean corneal flap of appropriate depth.

• Are affected by one of the common types of vision prob-lems or refractive error – myopia (nearsightedness), astig-matism (blurred vision caused by an irregular shaped cornea), hyperopia (farsightedness), or a combination thereof (e.g., myopia with astigmatism). Several lasers are now approved by the U.S. Food and Drug Administration (FDA) as safe and effective for use in LASIK, but the scope of each laser’s approved indication and treatment range is limited to specified degrees of refractive error.

• Do not suffer from any disease, vision-related or oth-erwise, that may reduce the effectiveness of the surgery or the patient’s ability to heal properly and quickly. • Are adequately informed about the benefits and risks of the procedure. Candidates should thoroughly discuss the procedure with their physicians and understand that for most people, the goal of refractive surgery should be the reduction of dependency on glasses and contact lens-es, not their complete elimination.

The ‘Less Than Ideal’

LASIK Candidate Sometimes, factors exist that preclude a candidate from being ideal for LASIK surgery. In many cases, a surgeon may still be able to perform the procedure safely, given that the candidate and physician have adequately dis-cussed the benefits and risks, and set realistic expecta-tions for the results. Candidates in this category include those who:

• Have a history of dry eyes, as they may find that the con-dition worsens following surgery.

• Are being treated with medications such as steroids or immunosuppressants, which can prevent healing, or are suffering from diseases that slow healing, such as autoim-mune disorders.

• Have scarring of the cornea.

More often, factors exist that may keep an individual from being a candidate immediately, but do not preclude the individual from being a candidate entirely. Candidates in this category include those who:

• Are under age 18. • Have unstable vision, which usually occurs in young people. Doctors recommend that, prior to undergoing LASIK, candidates’ vision has stabilized with a consis-tent glasses or contact lens prescription for at least two years.

• Are pregnant or nursing.

• Have a history of ocular herpes within one year prior to having the surgery. Once a year has passed from initial diagnosis of the disease, surgery can be considered.

• Have refractive errors too severe for treatment with current technology. Although FDA-approved lasers are available to treat each of the three major types of refrac-tive error – myopia, hyperopia and astigmatism – cur-rent FDA-approved indications define appropriate candidates as those with myopia up to -12 D, astigma-tism up to 6 D and hyperopia up to +6 D. However, laser eye surgery technology is evolving rapidly, and doctors may be able to treat more severe errors in the future.

The Non-LASIK Candidate

Certain conditions and circumstances completely pre-clude individuals from being candidates for LASIK surgery. Non-candidates include individuals who:
• Have diseases such as cataracts, advanced glaucoma, corneal diseases, corneal thinning disorders (keratoconus or pellucid marginal degeneration), or certain other pre-existing eye diseases that affect or threaten vision.

• Do not give informed consent. It is absolutely necessary that candidates adequately discuss the procedure and its benefits and risks with their surgeon, and provide the appropriate consent prior to undergoing the surgery.

• Have unrealistic expectations. It is critical for candidates to understand that laser eye surgery, as all surgical procedures, involves some risk. In addition, both the final outcome of surgery and the rate of healing vary from person to person and even from eye to eye in each individual.
III. Pre-LASIK Testing:

What Types of Screening Exams Should Patients Expect? Anyone considering LASIK should undergo a thorough examination by an eye care professional. The exam, and a follow-up consultation with the physician, can also identify ongoing health concerns that may affect the can-didate’s vision in the future, inform the candidate of poten-tial outcomes of LASIK, frame expectations for what the procedure can do, and inform the candidate of his or her vision health status. A list of preliminary or screening tests that should be performed routinely appears below. Additional testing, depending on preliminary findings and the special needs of the candidate, may also be appropriate. If, after an evaluation, a patient has questions about why a test was included or omitted, he/she should discuss the matter with the eye care professional in question. Certainly a patient can and should question why a test was omitted. The patient should be satisfied with the explanation before proceeding.

Assessment of Eye Health History

• History of wearing glasses: It is important to determine if a candidate’s vision has stabilized or is changing. If it is unstable, LASIK may not be appropriate at this time. The ideal candidate is at least 18 years of age with a stable glasses or contact lens prescription for at least 2 years.

• History of contact lens wear: Contact lenses may change the shape of the cornea (the clear front surface of the eye) or act in such a way as to prevent the ophthalmologist from determining a candidate’s correct prescription. Most ophthalmologists require that soft contact lenses be dis-continued at least 3 days and rigid contact lenses 2 to 3 weeks prior to the evaluation. If concern arises about contact lens-induced changes in the cornea, it may be necessary for a candidate to stop wearing contacts for as long as several months to allow the cornea to return to its natural contour, so that a surgical evaluation can be made.

• History of ocular or systemic diseases and medications: Some eye diseases and medications can affect the suit-ability of a candidate for LASIK.

• History of previous ocular problems such as lazy eyes, strabismus (eye misalignment caused by muscle imbal-ance), or the need for special glasses to prevent double vision.

• History of previous eye injury.

• Assessing vocational and lifestyle needs: The LASIK can-didate’s work or recreational activities and needs can influence vision correction strategies. For example, dif-ferent strategies can affect depth perception and the abil-ity to see near or far.

A Comprehensive Examination of the Eye

• Determination of uncorrected vision and vision as cor-rected by glasses or contacts.

• Determination of the magnitude of visual error in each eye to establish the amount of surgical correction that is needed and develop the appropriate surgical strategy.

• Assessment of the surface of the cornea by “mapping” its topography (corneal curvature or shape), to correlate its shape to errors in focusing (correlate corneal shape to refractive astigmatism), to find irregularities, if any, and to screen for disease states that may produce poor out-comes with LASIK.

• Measurement of pupil size in dim and room light. Pupil size is an important factor in counseling a candidate about night vision and planning the appropriate laser vision correction strategy.

• Assessment of motility to measure the ability of the muscles to align the eyes. • Examination of the eyelids to see if they turn inward (possibly scratching the cornea) or outward and redirect tear flow away from the eye, and other conditions. • Examination of the conjunctiva, the transparent mem-brane that covers the outer surface of the eye and lines the inner surface of the eyelids, to see whether there are irri-tations, redness, irregular blood vessels or other abnor-malities. • Examination of the cornea to determine if there are any abnormalities that could affect the outcome of surgery. • Examination of the crystalline lens to determine if cloud-ing of the lens (cataract) or other abnormalities are present.

• Measurement of corneal thickness (pachymetry). The amount of LASIK correction may be determined in part by corneal thickness. • Measurement of intraocular pressure to detect glauco-ma or pre-glaucomatous conditions. Glaucoma is a visu-al loss caused by damage to the optic nerve from excessively high pressures in the eye. It is a common cause of pre-ventable vision loss. • Assessment of the back (posterior segment) of the eye: The dilated fundus exam is used to assess the health of the inside back surface of the eye (retina), with the pupil fully open. Examination of the retina, optic nerve, and blood vessels screens for a number of eye and systemic disorders. • Follow-up should include review of examination results by an ophthalmologist, discussion with the candidate, additional testing as necessary, and adoption of a plan for managing the candidate’s eye-care needs.
IV. Realistic Expectations: Why Are They Central to Patient Satisfaction?

The overwhelming majority of patients who have had LASIK surgery are fully satisfied with their results – hav-ing experienced the significant benefits of improved vision. However, as with any medical or surgical proce-dure, for certain patients the outcome of the procedure may not seem “ideal” or meet all of his/her expectations. A small minority of patients may also experience com-plications. Therefore, it is crucial that LASIK surgery can-didates thoroughly discuss the procedure — its benefits, risks and probable outcomes — with their physician prior to undergoing the surgery. Each patient should be fully informed and feel comfortable that they are making an educated decision based upon facts. Candidates should be aware that:

• LASIK cannot provide perfect vision every time for every patient. However, for the majority of LASIK candidates, the surgery improves vision and reduces the need for cor-rective eyewear. In fact, the vast majority of patients with low to moderate nearsightedness achieve 20/40 vision or better, and many can expect to achieve 20/20 vision or better.

• Re-treatments (enhancements) may be required to achieve optimal outcomes. Fortunately, it is possible to repeat the laser treatment by lifting the flap, typically about three months after the original procedure. Even after enhancements, vision after LASIK may not be as good as it was with glasses or contact lenses before the pro-cedure. • There may be visual aberrations after LASIK—most com-monly, glare and halos under dim lighting conditions. Usually, these are not significant, and resolve within sev-eral months of surgery. Occasionally, they are severe enough to interfere with normal activities.

• Monovision is a technique in which one eye is correct-ed for distance vision and the other is left nearsighted to focus on near objects without glasses. Today, it is the only way that LASIK candidates older than about 45 years can avoid reading glasses. LASIK will not cure presbyopia, the aging changes that prevent older people from seeing near objects through the same glasses that they use for view-ing distant objects.

• LASIK surgery, as all surgical procedures, has the risk of complications. Fortunately, the likelihood of visual loss with LASIK is very small. In the many millions of LASIK procedures done so far, less than one percent of patients have experienced serious, vision threatening problems. Most complications represent delays in full recovery and resolve within several months of surgery. V. Initiating A Dialogue: What Should I Ask My Doctor? The decision to have LASIK should be an informed one, made in close consultation with an eye care profession-al. In order to understand whether LASIK is right for them, patients considering the procedure should ask the fol-lowing questions of their doctor:

• What type of testing will you do in order to determine whether I’m a candidate for LASIK?

• Has my glasses or contact lens prescription been con-sistent for at least two years?

• Does my nearsightedness, farsightedness or astigmatism fall within the accepted levels established for surgery by the FDA?

• Are my corneas thick enough to perform LASIK surgery?

• Do I have cataracts, glaucoma or other corneal diseases?

• Are my corneas scarred?

• Do I have any diseases that would affect the outcome of the surgery or my ability to heal properly?

• Are there any other reasons why I may not be a candi-date for LASIK surgery? • Am I at risk for complications?

• What can I expect during the procedure?

• What outcome can I expect from the surgery?

The Eye Surgery Education Council (ESEC) is an initia-tive established by the American Society of Cataract and Refractive Surgery (ASCRS), a professional society of oph-thalmologists dedicated to raising the standards and skills of surgeons, who operate on the anterior (front) segment of the eye, through clinical education, and to work with patients, government, and the medical community to promote delivery of quality eye care. The ESEC, which is committed to helping patients make informed decisions about undergoing laser eye surgery, has two missions -- to provide patients with accurate, accessible informa-tion, and to promote active physician/patient discussion about the benefits and risks of laser eye surgery procedures.

The information provided in these patient guidelines is intended to provide educational information to eye care professionals and is not intended to establish a par-ticular standard of care, provide an exhaustive discus-sion of the subject of laser eye surgery, or serve as a substitute for the application of the individual physician’s medical judgment in the particular circumstances presented by each patient care situation.

Candidates and prospective candidates for laser eye surgery should likewise understand that the information provided in these guidelines is educational in nature and is not intended to serve as a substitute for medical advice. The decision whether to undergo laser eye surgery must be made by each individual based on the relevant facts and circumstances acting in consultation with a quali-fied eye care professional.

3D Medical Animation of a Knee Replacement

2008-01-30T10:22:00.001-08:00

If your knee is severely damaged by arthritis or injury, it may be hard for you to perform simple activities such as walking or climbing stairs. You may even begin to feel pain while you are sitting or lying down.

If medications, changing your activity level, and using walking supports are no longer helpful, you may want to consider total knee replacement surgery. By resurfacing the damaged and worn surfaces of the knee can relieve pain, correct leg deformity and help resume normal activities.

One of the most important orthopaedic surgical advances of the twentieth century, knee replacement was first performed in 1968. Improvements in surgical materials and techniques since then have greatly increased its effectiveness. Approximately 300,000 knee replacements are performed each year in the United States.

Whether you have just begun exploring treatment options or have already decided with your orthopaedic surgeon to have total knee replacement surgery, this booklet will help you understand more about this valuable procedure.

Anatomy

The knee is the largest joint in the body. Normal knee function is required to perform most everyday activities. The knee is made up of the lower end of the thighbone (femur), which rotates on the upper end of the shin bone (tibia), and the kneecap (patella), which slides in a groove on the end of the femur. Large ligaments attach to the femur and tibia to provide stability. The long thigh muscles give the knee strength.

The joint surfaces where these three bones touch are covered with articular cartilage, a smooth substance that cushions the bones and enables them to move easily.

All remaining surfaces of the knee are covered by a thin, smooth tissue liner called the synovial membrane. This membrane releases a special fluid that lubricates the knee, reducing friction to nearly zero in a healthy knee.

Normally, all of these components work in harmony. But disease or injury can disrupt this harmony, resulting in pain, muscle weakness, and reduced function.

Common Causes of Knee Pain and Loss of Knee Function

Normal knee anatomy.

The most common cause of chronic knee pain and disability is arthritis. Osteoarthritis, rheumatoid arthritis, and traumatic arthritis are the most common forms.

Osteoarthritis usually occurs in people 50 years of age and older and often in individuals with a family history of arthritis. The cartilage that cushions the bones of the knee softens and wears away. The bones then rub against one another, causing knee pain and stiffness.
Rheumatoid arthritis is a disease in which the synovial membrane becomes thickened and inflamed, producing too much synovial fluid that overfills the joint space. This chronic inflammation can damage the cartilage and eventually cause cartilage loss, pain, and stiffness.
Traumatic arthritis can follow a serious knee injury. A knee fracture or severe tears of the knee ligaments may damage the articular cartilage over time, causing knee pain and limiting knee function.

Is Total Knee Replacement for You?

Knee with arthritis.

Whether to have total knee replacement surgery should be a cooperative decision made by you, your family, your family physician, and your orthopaedic surgeon. Your physician may refer you to an orthopaedic surgeon for a thorough evaluation to determine if you could benefit from this surgery. Alternatives to traditional total knee replacement surgery that your orthopaedic surgeon may discuss with you include a unicompartmental knee replacement or a minimally invasive knee replacement.

Reasons that you may benefit from total knee replacement commonly include:

Severe knee pain that limits your everyday activities, including walking, climbing stairs, and getting in and out of chairs. You may find it hard to walk more than a few blocks without significant pain and you may need to use a cane or walker.
Moderate or severe knee pain while resting, either day or night
Chronic knee inflammation and swelling that does not improve with rest or medications
Knee deformity: a bowing in or out of your knee
Knee stiffness: inability to bend and straighten your knee
Failure to obtain pain relief from nonsteroidal anti-inflammatory drugs. These medications, including aspirin and ibuprofen, often are most effective in the early stages of arthritis. Their effectiveness in controlling knee pain varies greatly from person to person. These drugs may become less effective for patients with severe arthritis.
Inability to tolerate or complications from pain medications
Failure to substantially improve with other treatments such as cortisone injections, physical therapy, or other surgeries

Most patients who undergo total knee replacement are age 60 to 80, but orthopaedic surgeons evaluate patients individually. Recommendations for surgery are based on a patient's pain and disability, not age. Total knee replacements have been performed successfully at all ages, from the young teenager with juvenile arthritis to the elderly patient with degenerative arthritis.

The Orthopaedic Evaluation

The orthopaedic evaluation consists of several components:

A medical history, in which your orthopaedic surgeon gathers information about your general health and asks you about the extent of your knee pain and your ability to function
A physical examination to assess knee motion, stability, strength, and overall leg alignment
X-rays (radiographs) to determine the extent of damage and deformity in your knee
Occasionally blood tests, MRI (magnetic resonance imaging), or bone scanning may be needed to determine the condition of the bone and soft tissues of your knee.

Your orthopaedic surgeon will review the results of your evaluation with you and discuss whether total knee replacement would be the best method to relieve your pain and improve your function. Other treatment options-including medications, injections, physical therapy, or other types of surgery-also will be discussed and considered.

Your orthopaedic surgeon also will explain the potential risks and complications of total knee replacement, including those related to the surgery itself and those that can occur over time after your surgery.

Realistic Expectations About Knee Replacement Surgery

An important factor in deciding whether to have total knee replacement surgery is understanding what the procedure can and cannot do.

More than 90% of individuals who undergo total knee replacement experience a dramatic reduction of knee pain and a significant improvement in the ability to perform common activities of daily living. But total knee replacement will not make you a super-athlete or allow you to do more than you could before you developed arthritis.

Following surgery, you will be advised to avoid some types of activity, including jogging and high-impact sports, for the rest of your life.

With normal use and activity, every knee replacement develops some wear in its plastic cushion. Excessive activity or weight may accelerate this normal wear and cause the knee replacement to loosen and become painful. With appropriate activity modification, knee replacements can last for many years.

Preparing for Surgery

Medical Evaluation

If you decide to have total knee replacement surgery, you may be asked to have a complete physical examination by your family physician several weeks before surgery to assess your health and to identify any conditions that could interfere with your surgery.

Tests

Several tests may be needed to help plan your surgery: blood and urine samples may be tested and a cardiogram may be obtained.

Preparing Your Skin and Leg

Your knee and leg should not have any skin infections or irritation. Your lower leg should not have any chronic swelling. Contact your orthopaedic surgeon prior to surgery if either of these conditions is present for a program to best prepare your skin for surgery.

Blood Donation

You may be advised to donate your own blood prior to the surgery. It will be stored in the event you need blood after your surgery.

Medications

Tell your orthopaedic surgeon about the medications you are taking. He or she will tell you which medications you should stop taking and which you should continue to take before surgery.

Dental Evaluation

Although the incidence of infection after knee replacement is very low, an infection can occur if bacteria enter your bloodstream. Treatment of significant dental diseases (including tooth extractions and periodontal work) should be considered before your total knee replacement surgery.

Urinary Evaluations

A preoperative urological evaluation should be considered for individuals with a history of recent or frequent urinary infections. For older men with prostate disease, required treatment should be considered prior to knee replacement surgery.

Social Planning

Although you will be able to walk on crutches or a walker soon after surgery, you will need help for several weeks with such tasks as cooking, shopping, bathing, and doing laundry. If you live alone, your orthopaedic surgeon's office and a social worker, or a discharge planner at the hospital can help you make advance arrangements to have someone assist you at home. They also can help you arrange for a short stay in an extended-care facility during your recovery, if this option works best for you.

Home Planning

The following is a list of modifications that can make your home easier to navigate during your recovery:

Safety bars or a secure handrail in your shower or bath
Secure handrails along your stairways
A stable chair for your early recovery with a firm seat cushion (and a height of 18 to 20 inches), a firm back, two arms, and a footstool for intermittent leg elevation
A toilet seat riser with arms, if you have a low toilet
A stable shower bench or chair for bathing
Removing all loose carpets and cords
A temporary living space on the same floor because walking up or down stairs will be more difficult during your early recovery

Your Surgery

You will most likely be admitted to the hospital on the day of your surgery. After admission, you will be evaluated by a member of the anesthesia team. The most common types of anesthesia are general anesthesia, in which you are asleep throughout the procedure, and spinal or epidural anesthesia, in which you are awake but your legs are anesthetized. The anesthesia team will determine which type of anesthesia will be best for you with your input.

The procedure itself takes approximately 2 hours. Your orthopaedic surgeon will remove the damaged cartilage and bone and then position the new metal and plastic joint surfaces to restore the alignment and function of your knee.

Many different types of designs and materials are currently used in total knee replacement surgery, nearly all of which consist of three components: the femoral component (made of a highly polished strong metal), the tibial component (made of a durable plastic often held in a metal tray), and the patellar component (also plastic).

After surgery, you will be moved to the recovery room, where you will remain for 1 to 2 hours while your recovery from anesthesia is monitored. After you awaken, you will be taken to

Unicompartmental Knee Replacement

Although not as common as total knee replacement, the partial or unicompartmental knee replacement (commonly called the "uni") is a viable alternative in limited situations. The designs of the unicompartmental types of knee replacements have improved over the years, as has the sophistication of the instruments used to implant these types of artificial joints. The unicompartmental knee replacement also has smaller, less invasive incisions.

The unicompartmental knee replacement is used to replace a single compartment of the arthritic knee. The knee joint has three compartments: the medial (inner) compartment, the lateral (outer) compartment, and the patellofemoral (kneecap) compartment. If the damage is limited to either the medial or lateral compartment, that compartment may be replaced with the unicompartmental knee implant.

If two or more compartments are damaged, unicompartmental knee replacement may not be the best option. Unicompartmental knee replacement is also less desirable for a young, active person because it may not withstand the extremes of stress that high levels of activity create. It is best suited for the older, slim person with a relatively sedentary lifestyle. Only between 6 and 8 out of 100 patients with arthritic knees are good candidates for unicompartmental knee replacement.

Because the unicompartmental knee replacement can be inserted through a relatively small incision (approximately 3 to 4 inches long), which does not interrupt the main muscle controlling the knee, rehabilitation is faster, hospitalization is shorter, and return to normal activities is more rapid than after a total knee replacement.

However, this is still a serious surgical procedure, and has all of the same risks as total knee replacement. These risks, as well as whether you are a good candidate for unicompartmental knee replacement, should be discussed with your orthopaedic surgeon.

Minimally Invasive Knee Replacement

A recent advance in the performance of total knee replacement is the use of minimally invasive surgical approaches. This technique, still in its relative infancy, is more challenging than standard total knee replacement. The incisions are approximately half the size of those used in a standard approach. The smaller incisions and new techniques to expose the joint may result in short-term advantages such as a quicker rehabilitation, less pain, and a shorter hospitalization, according to some reports.

The minimally invasive approach to the total knee replacement is appropriate for non-obese patients who have reasonable motion without significant deformity. Hospitalization may be reduced to 1 to 3 days among these patients, and the need for an extended stay for inpatient rehabilitation may be reduced or eliminated in most patients.

Although some studies show shorter hospitalizations and rehabilitation periods, other studies find minimally invasive surgical techniques to be no better than standard techniques. Although the risks are not well known, they are probably comparable to those for a standard total knee replacement. Speak to your orthopaedic surgeon about whether you are an appropriate candidate for this particular approach to total knee replacement.

Your Stay in the Hospital

You will most likely stay in the hospital for several days. After surgery, you will feel some pain, but medication will be given to you to make you feel as comfortable as possible. Because pain management is an important part of your recovery, talk with your surgeon if postoperative pain becomes a problem. Walking and knee movement are important to your recovery and will begin immediately after your surgery.

To avoid lung congestion after surgery, you should breathe deeply and cough frequently to clear your lungs.

Your orthopaedic surgeon may prescribe one or more measures to prevent blood clots and decrease leg swelling, such as special support hose, inflatable leg coverings (compression boots), and blood thinners.

To restore movement in your knee and leg, your surgeon may use a knee support that slowly moves your knee while you are in bed. The device, called a continuous passive motion (CPM) exercise machine, decreases leg swelling by elevating your leg and improves your venous circulation by moving the muscles of your leg.

Foot and ankle movement also is encouraged immediately following surgery to increase blood flow in your leg muscles to help prevent leg swelling and blood clots. Most patients begin exercising their knee the day after surgery. A physical therapist will teach you specific exercises to strengthen your leg and restore knee movement to allow walking and other normal daily activities soon after your surgery.

Complications

The complication rate following total knee replacement is low. Serious complications, such as a knee joint infection, occur in fewer than 2% of patients. Major medical complications such as heart attack or stroke occur even less frequently. Chronic illnesses may increase the potential for complications. Although uncommon, when these complications occur, they can prolong or limit full recovery.

Blood clots in the leg veins are the most common complication of knee replacement surgery. Your orthopaedic surgeon will outline a prevention program, which may include periodic elevation of your legs, lower leg exercises to increase circulation, support stockings, and medication to thin your blood.

Although implant designs and materials as well as surgical techniques have been optimized, wear of the bearing surfaces or loosening of the components may occur. Additionally, although an average of 115° of motion is generally anticipated after surgery, scarring of the knee can occasionally occur, and motion may be more limited, particularly in patients with limited motion before surgery. Finally, although rare, injury to the nerves or blood vessels around the knee can occur during surgery.

Discuss your concerns thoroughly with your orthopaedic surgeon prior to surgery.

Your Recovery at Home

The success of your surgery also will depend on how well you follow your orthopaedic surgeon's instructions at home during the first few weeks after surgery.

Wound Care

You will have stitches or staples running along your wound or a suture beneath your skin on the front of your knee. The stitches or staples will be removed several weeks after surgery. A suture beneath your skin will not require removal.

Avoid soaking the wound in water until the wound has thoroughly sealed and dried. The wound may be bandaged to prevent irritation from clothing or support stockings.

Diet

Some loss of appetite is common for several weeks after surgery. A balanced diet, often with an iron supplement, is important to promote proper tissue healing and to restore muscle strength.

Activity

Exercise is a critical component of home care, particularly during the first few weeks after surgery. You should be able to resume most normal activities of daily living within 3 to 6 weeks following surgery. Some pain with activity and at night is common for several weeks after surgery. Your activity program should include:

A graduated walking program to slowly increase your mobility, initially in your home and later outside
Resuming other normal household activities, such as sitting and standing and climbing stairs
Specific exercises several times a day to restore movement and strengthen your knee. You probably will be able to perform the exercises without help, but you may have a physical therapist help you at home or in a therapy center the first few weeks after surgery.

Driving usually begins when your knee bends sufficiently so you can enter and sit comfortably in your car and when your muscle control provides adequate reaction time for braking and acceleration. Most individuals resume driving approximately 4 to 6 weeks after surgery.

Avoiding Problems After Surgery

Blood Clot Prevention

Follow your orthopaedic surgeon's instructions carefully to minimize the potential of blood clots that can occur during the first several weeks of your recovery.

Warning Signs

Warning signs of possible blood clots in your leg include:

Increasing pain in your calf
Tenderness or redness above or below your knee
Increasing swelling in your calf, ankle, and foot

Warning signs that a blood clot has traveled to your lung include:

Sudden increased shortness of breath
Sudden onset of chest pain
Localized chest pain with coughing

Notify your doctor immediately if you develop any of these signs.

Preventing Infection

The most common causes of infection following total knee replacement surgery are from bacteria that enter the bloodstream during dental procedures, urinary tract infections, or skin infections. These bacteria can lodge around your knee replacement and cause an infection.

For the first 2 years after your knee replacement, you must take preventive antibiotics before dental or surgical procedures that could allow bacteria to enter your bloodstream. After 2 years, talk to your orthopaedist and your dentist or urologist to see if you still need preventive antibiotics before any scheduled procedures.

Warning signs of a possible knee replacement infection are:

Persistent fever (higher than 100°F orally)
Shaking chills
Increasing redness, tenderness, or swelling of the knee wound
Drainage from the knee wound
Increasing knee pain with both activity and rest

Notify your doctor immediately if you develop any of these signs.

Avoiding Falls

A fall during the first few weeks after surgery can damage your new knee and may result in a need for further surgery. Stairs are a particular hazard until your knee is strong and mobile. You should use a cane, crutches, a walker, or hand rails or have someone to help you until you have improved your balance, flexibility, and strength.

Your surgeon and physical therapist will help you decide what assistive aides will be required following surgery and when those aides can safely be discontinued.

How Your New Knee Is Different

You may feel some numbness in the skin around your incision. You also may feel some stiffness, particularly with excessive bending activities. Improvement of knee motion is a goal of total knee replacement, but restoration of full motion is uncommon. The motion of your knee replacement after surgery is predicted by the motion of your knee prior to surgery. Most patients can expect to be able to almost fully straighten the replaced knee and to bend the knee sufficiently to climb stairs and get in and out of a car. Kneeling is usually uncomfortable, but it is not harmful. Occasionally, you may feel some soft clicking of the metal and plastic with knee bending or walking. These differences often diminish with time and most patients find them to be tolerable when compared with the pain and limited function they experienced prior to surgery.

Your new knee may activate metal detectors required for security in airports and some buildings. Tell the security agent about your knee replacement if the alarm is activated.

After surgery, make sure you also do the following:

Participate in regular light exercise programs to maintain proper strength and mobility of your new knee.
Take special precautions to avoid falls and injuries. Individuals who have undergone total knee replacement surgery and experience a fracture may require more surgery.
Notify your dentist that you had a knee replacement. You should be given antibiotics before all dental surgery for the rest of your life.
See your orthopaedic surgeon periodically for a routine follow-up examination and x-rays (radiographs), usually once a year.

Your orthopaedic surgeon is a medical doctor with extensive training in the diagnosis and nonsurgical and surgical treatment of the musculoskeletal system, including bones, joints, ligaments, tendons, muscles, and nerves.

This information has been prepared by the American Academy of Orthopaedic Surgeons and is intended to contain current information on the subject from recognized authorities. However, it does not represent official policy of the AAOS and its text should not be construed as excluding other acceptable viewpoints. Persons with questions about a medical condition should consult a physician who is informed about the condition and the various modes of treatment available.

Autoimmune Disorders

2008-01-29T06:51:00.000-08:00

What is the immune system?
The immune system is the body's means of protection against microorganisms and other "foreign" substances. It is composed of two major parts. One component, B lymphocytes, produces antibodies, proteins that attack "foreign" substances and cause them to be removed from the body; this is sometimes called the humoral immune system. The other component consists of special white blood cells called T lymphocytes, which can attack "foreign" substances directly; this is sometimes called the cellular immune system. It takes time for both components of the immune system to develop. The only protections a newborn will have are the antibodies that have transferred from the mother to the baby before birth. T lymphocytes become protective, and antibodies are developed after a person is exposed to specific "foreign" threats. Over a lifetime, the immune system develops an extensive library of identified substances and microorganisms that are cataloged as “threat” or “not threat.” Vaccinations utilize this process to add to the library. They expose a person’s immune system to weakened or inactivated forms of bacteria and viruses that can no longer cause disease, so that the person’s immune system will recognize them and create antibodies that will be ready to protect against the infectious forms of these microorganisms if the person comes in contact with them in the future.

Normally, the immune system can distinguish between “self” and “not self” and only attacks those tissues that it recognizes as “not self.” This is usually the desired response, but not always. When a person is given an organ transplant, the immune system will correctly recognize the new organ as “not self” (unless it is from an identical twin) and will attack it in a process called rejection. To prevent rejection, the transplant patient must take drugs that reduce the activity of the immune system (immunosuppressants) for the rest of his life.

What are autoimmune disorders?
Autoimmune disorders are diseases caused by the body producing an inappropriate immune response against its own tissues. Sometimes the immune system will cease to recognize one or more of the body’s normal constituents as “self” and will create autoantibodies – antibodies that attack its own cells, tissues, and/or organs. This causes inflammation and damage and it leads to autoimmune disorders.

The cause of autoimmune diseases is unknown, but it appears that there is an inherited predisposition to develop autoimmune disease in many cases. In a few types of autoimmune disease (such as rheumatic fever), a bacteria or virus triggers an immune response, and the antibodies or T-cells attack normal cells because they have some part of their structure that resembles a part of the structure of the infecting microorganism.

Autoimmune disorders fall into two general types: those that damage many organs (systemic autoimmune diseases) and those where only a single organ or tissue is directly damaged by the autoimmune process (localized). However, the distinctions become blurred as the effect of localized autoimmune disorders frequently extends beyond the targeted tissues, indirectly affecting other body organs and systems. Some of the most common types of autoimmune disorders include:

Systemic Autoimmune Diseases

Localized Autoimmune Diseases

Rheumatoid arthritis (RA) and Juvenile RA (JRA) (joints; less commonly lung, skin)

Type 1 Diabetes Mellitus (pancreas islets)

Lupus [Systemic Lupus Erythematosus] (skin, joints, kidneys, heart, brain, red blood cells, other)

Hashimoto's thyroiditis, Graves' disease (thyroid)

Scleroderma (skin, intestine, less commonly lung)

Celiac disease, Crohn's disease, Ulcerative colitis (GI tract)

Sjogren's syndrome (salivary glands, tear glands, joints)

Multiple sclerosis*

Goodpasture's syndrome (lungs, kidneys)

Addison's disease (adrenal)

Wegener's granulomatosis (blood vessels, sinuses, lungs, kidneys)

Primary biliary cirrhosis, Sclerosing cholangitis, Autoimmune hepatitis (liver)

Polymyalgia Rheumatica (large muscle groups)

Temporal Arteritis / Giant Cell Arteritis (arteries of the head and neck)

Guillain-Barre syndrome (nervous system)

* There is still some debate as to whether MS is an autoimmune disease

For a more complete list of autoimmune conditions, visit the Patient Information page of the American Autoimmune Related Diseases Association, Inc.

In some cases, a person may have more than one autoimmune disease; for example, persons with Addison's disease often have type 1 diabetes, while persons with sclerosing cholangitis often have ulcerative colitis.

In some cases, the antibodies may not be directed at a specific tissue or organ; for example, antiphospholipid antibodies can react with clotting proteins in the blood, leading to formation of blood clots within the blood vessels (thrombosis).

Autoimmune disorders are diagnosed, evaluated, and monitored through a combination of autoantibody blood tests, blood tests to measure inflammation and organ function, clinical presentation, and through non-laboratory examinations such as X-rays. There is currently no cure for autoimmune disorders, although in rare cases they may disappear on their own. Many people may experience flare-ups and temporary remissions in symptoms, others chronic symptoms or a progressive worsening. Treatment of autoimmune disorders is tailored to the individual and may change over time. The goal is to relieve symptoms, minimize organ and tissue damage, and preserve organ function. New treatments and a greater understanding of autoimmune disorders are being researched. Patients should talk to their doctors and to any specialists they are referred to about their treatment options.

For more information on specific autoimmune disorders, see the related condition pages and web sites listed below.

Herniated Disc

2008-01-28T08:03:00.000-08:00

The bones (vertebrae) that form the spine in your back are cushioned by small discs. These discs are round and flat, with a tough, outer layer (annulus) that surrounds a jellylike material called the nucleus. Located between each of your vertebra in the spinal column, discs act as shock absorbers for the spinal bones. Thick ligaments attached to the vertebrae hold the pulpy disc material in place.

A herniated (also called a slipped or ruptured) disc is a fragment of the disc nucleus which is pushed out of the annulus, into the spinal canal through a tear or rupture. Discs that become herniated are usually in an early stage of degeneration. The spinal canal has limited space which is inadequate for the spinal nerve and the displaced herniated disc fragment. Due to this displacement, the disc presses on spinal nerves, often producing pain, which may be severe.

Herniated discs can occur in any part of the spine. Herniated discs are more common in the lower back (lumbar spine), but also occur in the neck (cervical spine). The area in which you experience pain depends on what part of the spine is affected.

Causes

A single excessive strain or injury may cause a herniated disc. However, disc material degenerates naturally as you age, and the ligaments that hold it in place begin to weaken. As this degeneration progresses, a relatively minor strain or twisting movement can cause a disc to rupture.

Certain individuals may be more vulnerable to disc problems, and as a result may suffer herniated discs in several places along the spine. Research has shown that a predisposition for herniated discs may exist in families, with several members affected.

Herniated Disc Symptoms

Symptoms vary greatly depending on the position of the herniated disc and the size of the herniation. If the herniated disc is not pressing on a nerve, you may experience a low backache or no pain at all. If it is pressing on a nerve, there may be pain, numbness, or weakness in the area of the body to which the nerve travels. Typically, a herniated disc is preceded by an episode of low back pain or a long history of intermittent episodes of low back pain.

Lumbar spine (lower back): Sciatica frequently results from a herniated disc in the lower back. Pressure on one or several nerves that contribute to the sciatic nerve can cause pain, burning, tingling, and numbness that radiates from the buttock into the leg and sometimes into the foot. Usually one side (left or right) is affected. This pain often is described as sharp and electric shock-like. It may be more severe with standing, walking or sitting. Along with leg pain, you may experience low back pain.

Cervical spine (neck): Symptoms may include dull or sharp pain in the neck or between the shoulder blades, pain that radiates down the arm to the hand or fingers, or numbness or tingling in the shoulder or arm. The pain may increase with certain positions or movements of the neck.

Diagnosis

Diagnosis is made by a neurosurgeon based on your history, symptoms, a physical examination, and results of tests, including the following:

* X-ray: Application of radiation to produce a film or picture of a part of the body can show the structure of the vertebrae and the outline of the joints. X-rays of the spine are obtained to search for other potential causes of pain, i.e. tumors, infections, fractures, etc.
* Computed tomography scan (CT or CAT scan): A diagnostic image created after a computer reads x-rays; can show the shape and size of the spinal canal, its contents, and the structures around it.
* Magnetic resonance imaging (MRI): A diagnostic test that produces three-dimensional images of body structures using powerful magnets and computer technology; can show the spinal cord, nerve roots, and surrounding areas, as well as enlargement, degeneration, and tumors.
* Myleogram: An x-ray of the spinal canal following injection of a contrast material into the surrounding cerebrospinal fluid spaces; can show pressure on the spinal cord or nerves due to herniated discs, bone spurs or tumors.
* Electromyogram and Nerve Conduction Studies (EMG/NCS): These tests measure the electrical impulse along nerve roots, peripheral nerves, and muscle tissue. This will indicate whether there is ongoing nerve damage, if the nerves are in a state of healing from a past injury, or whether there is another site of nerve compression.

Treatment

Fortunately, the majority of herniated discs do not require surgery. However, a very small percentage of people with herniated, degenerated discs may experience symptomatic or severe and incapacitating low back pain which significantly affects their daily life.

The initial treatment for a herniated disc is usually conservative and nonsurgical. Your doctor may prescribe bed rest, or advise you to maintain a low, painless activity level for a few days to several weeks. This helps the spinal nerve inflammation to decrease.

A herniated disc is frequently treated with nonsteroidal anti-inflammatory medication if the pain is only mild to moderate. An epidural steroid injection may be performed utilizing a spinal needle under x-ray guidance to direct the medication to the exact level of the disc herniation.

Your doctor may recommend physical therapy. The therapist will perform an in-depth evaluation; which combined with the doctor�s diagnosis, will dictate a treatment specifically designed for patients with herniated discs. Therapy may include pelvic traction, gentle massage, ice and heat therapy, ultrasound, electrical muscle stimulation, and stretching exercises. Pain medication and muscle relaxants may also be beneficial in conjunction with the physical therapy.

Surgery

Your doctor may recommend surgery if conservative treatment options, such as physical therapy and medications do not reduce or end the pain altogether. He or she will talk to you about the types of spinal surgery available, and depending on your specific case, will help to determine what procedure might be an appropriate treatment for you. As with any surgery, a patient�s age, overall health, and other issues are taken into consideration when surgery is considered.

The benefits of surgery should always be weighed carefully against its risks. Although a large percentage of patients with herniated discs report significant pain relief after surgery, there is no guarantee that surgery will help every individual.

You may be considered a candidate for spinal surgery if:

* Back and leg pain limits normal activity or impairs your quality of life
* You develop progressive neurological deficits, such as leg weakness and/or numbness
* You experience loss of normal bowel and bladder functions
* You have difficulty standing or walking
* Medication and physical therapy are ineffective
* You are in reasonably good health

Surgical Terms

* Artificial disc surgery � Surgical replacement of a diseased or herniated lumbar disc with a manufactured disc. The CHARITÉ� artificial disc consists of a plastic core between two chrome plates that lock into the spine.
* Discectomy � Surgical removal or partial removal of an intervertebral disc.
* Laminectomy � Surgical removal of most of the bony arch, or lamina of a vertebra.
* Laminotomy � An opening made in a lamina, to relieve pressure on the nerve roots.
* Spinal Fusion � A procedure in which bone is grafted onto the spine, creating a solid union between two or more vertebrae; and in which instrumentation such as screws and rods may be used to provide additional spinal support.

Lumbar Spine Surgery

Lumbar laminotomy is a procedure often utilized to relieve leg pain and sciatica caused by a herniated disc. It is performed through an incision down the center of the back over the area of the herniated disc. During this procedure, a portion of the lamina may be removed. Once the incision is made through the skin, the muscles are moved to the side so that the surgeon can see the back of the vertebrae. A small opening is made between the two vertebrae to gain access to the herniated disc. After the disc is removed through a discectomy, the spine must be stabilized. Spinal fusion is often performed in conjunction with a laminotomy. In more involved cases, a laminectomy may be performed.

In artificial disc surgery, an incision is made through the abdomen and the affected disc is removed and replaced. Only a small percentage of patients are candidates for artificial disc surgery. You must have disc degeneration in only one disc, between L4 and L5, or L5 and S1 (the first sacral vertebra). You must have undergone at least six months of treatment, such as physical therapy, pain medication, or wearing a back brace, without showing improvement. You must be in overall good health with no signs of infection, osteoporosis or arthritis. If you have degeneration affecting more than one disc, or significant leg pain, you are not a candidate for this surgery.

Cervical Spine Surgery

The medical decision to perform the operation from the front of the neck (anterior) or the back of the neck (posterior) is influenced by the exact location of the herniated disc, as well as the experience and preference of the surgeon. A portion of the lamina may be removed through a laminotomy, followed by a discectomy. After the disc is removed, the spine often needs to be stabilized. This is accomplished using a cervical plate and screws (instrumentation) and often, spinal fusion.

Postsurgery

Your doctor will give you specific instructions postsurgery and usually prescribe pain medication. Your doctor will help determine when you can resume normal activities such as returning to work, driving and exercising. Some patients may benefit from supervised rehabilitation or physical therapy after surgery. Discomfort is expected while you gradually return to normal activity, but pain is a warning signal that you might need to slow down.

Prevention Tips

Once you have recovered from surgery and have checked with your doctor, you may resume moderate exercise. The following tips may be helpful in preventing low back pain and herniated discs.

* Do crunches and other abdominal-muscle strengthening exercises to provide more spine stability. Swimming, stationary bicycling and brisk walking are good aerobic exercises that generally do not put extra stress on your back.

* Use correct lifting and moving techniques, such as squatting to lift a heavy object. Don't bend and lift. Get help if an object is too heavy or awkward.

* Maintain correct posture when you're sitting and standing.

* If you smoke, quit. Smoking is a risk factor for artherosclerosis (hardening of the arteries), which can cause lower back pain and degenerative disc disorders.

* Avoid stressful situations if possible, as this can cause muscle tension.

* Maintain a healthy weight. Extra weight, especially around the midsection, can put strain on your lower back.

2006 Medical Animation Reel

2008-01-27T06:17:00.000-08:00

Medical Animation
The medical animations at medical-animation.blogspot.com show you how the body's systems work and what happens when they break down. Learn what's really happening when you cough, how a kidney stone forms, how blood travels through the body and more, in the detailed animated videos in this section.

Bone Marrow Diseases

2008-01-26T00:30:00.001-08:00

Bone marrow is the spongy tissue inside some of your bones, such as your hip and thigh bones. It contains immature cells, called stem cells. The stem cells can develop into the red blood cells that carry oxygen through your body, the white blood cells that fight infections, and the platelets that help with blood clotting.

If you have a bone marrow disease, there are problems with the stem cells or how they develop. Leukemia is a cancer in which the bone marrow produces abnormal white blood cells. With aplastic anemia, the bone marrow doesn't make red blood cells. Other diseases, such as lymphoma, can spread into the bone marrow and affect the production of blood cells. Other causes of bone marrow disorders include your genetic makeup and environmental factors.

Symptoms of bone marrow diseases vary. Treatments depend on the disorder and how severe it is. They might involve medicines, blood transfusions or a bone marrow transplant.

The bone marrow biopsy and aspiration provide information about the status of and capability for blood cell production. They are not routinely ordered and in fact the majority of people will never have one done. A marrow aspiration and/or biopsy may be ordered to help evaluate blood cell production, to help diagnose leukemia, to help diagnose a bone marrow disorder, to help diagnose and stage a variety of other types of cancer (to determine spread into the marrow), and to help determine whether a severe anemia is due to decreased RBC production, increased loss, abnormal RBC production, and/or to a vitamin or mineral deficiency or excess. Conditions that affect the marrow can affect the number, mixture, and maturity of the cells, and can affect its fibrous structure.

A bone marrow sample may also be evaluated and cultured for the presence of microorganisms such as fungi, bacteria, or mycobacteria (such as that which causes tuberculosis) when the patient has a fever of unknown origin. Additional marrow testing may be ordered when it is suspected that the patient has a chromosomal abnormality and/or a disorder associated with iron storage that may cause iron to accumulate in the marrow.

When a person is being treated for a cancer, a bone marrow aspiration and/or biopsy may be ordered to evaluate the response to therapy to determine whether suppressed marrow function is beginning to return to normal.
A CBC and reticulocyte count are frequently ordered along with the bone marrow aspiration/biopsy. The results are used to help evaluate cell production in the marrow and compare it to current cell populations in circulation.

When is it ordered?
A bone marrow aspiration and/or biopsy may be indicated as follows:

As a diagnostic procedure when one of the following is suspected:

* Aplastic Anemia
* Acute Leukemia
* Myelodysplastic Syndrome
* Chronic Myelogenous Leukemia
* Myelofibrosis and Essential Thrombocythemia
* Multiple Myeloma
* Severe thrombocytopenia and/or anemia and/or neutropenia

As a staging procedure in:

* Hodgin’s and Non-Hodgkins lymphomas
* Small Cell Carcinoma of the Lung (although this not frequently done anymore)

For culturing:

* when fever is present in HIV/AIDS or other immuno-compromised patient
* in patients suspected of having Brucellosis or Typhoid Fever

A bone marrow biopsy and aspiration may also be ordered at intervals when a person is being treated for a cancer to evaluate whether marrow function is being suppressed and if it is, when its function begins to recover.

What does the test result mean?
With a bone marrow biopsy and aspiration the doctor is evaluating what is in the marrow in order to determine whether the cells found are normal and present in typical quantities, to determine whether there are cells present that shouldn’t be there (such as abnormal cells that are characteristic of specific cancers or disorders such as the Gaucher cell found with Gaucher’s disease or the foamy lipid-filled Niemann-Pick cell found with Niemann-Pick disease), and to determine what is missing.

The training and expertise of the pathologist or hematologist evaluating the marrow samples allows him to sort through the marrow clues and tell the doctor what is happening in the marrow. In most cases, this information can confirm or rule out a diagnosis and bone marrow involvement, but it can also point out the need for further investigation. For instance, if there are a decreased number of RBCs in the blood and an increased number of reticulocytes, and a marrow evaluation shows that RBC production appears normal but increased, then the doctor knows that marrow production of RBCs has increased appropriately to meet a RBC demand. What she still doesn’t know is the reason for the demand. It could be due to an acute or chronic loss of RBCs (such as may occur with gastrointestinal bleeding) or due to acute or chronic RBC destruction (such as sometimes occurs with an artificial heart valve).

A patient with few RBCs and no increase in reticulocytes may have aplastic anemia (suppressed RBC production in the marrow). An evaluation of the bone marrow may confirm this condition but it does not necessarily tell the doctor whether it is due to a bone marrow disorder, radiation, exposure to certain chemicals, some cancers, cancer treatment, or due to a tuberculosis infection.
The doctor takes the information that she receives from the marrow evaluation and combines it with information from a clinical examination, blood tests, and a variety of other tests, such as imaging scans and X-rays, to reach a final diagnosis. It can be a straightforward process or it can be a complex diagnostic puzzle. Patients should stay involved in this process by talking to their doctor before and after a bone marrow biopsy and/or aspiration, asking her what her suspicions are, what kind of information she is hoping to obtain from the evaluation, and what follow-up tests might be indicated.

Is there anything else I should know?
Complications from the bone marrow aspiration and/or biopsy procedure are rare, but some patients may have excessive bleeding at the collection site or develop an infection. Patients should tell the doctor about any allergies they have, and about any medications or supplements they are taking prior to the procedure and should contact their doctor promptly if they experience persistent or spreading redness or bleeding at the site, a fever, or increasing pain.

Cardiac angiography animation

2008-01-25T03:57:00.000-08:00

Alternative Names

Cardiac angiography; Angiography - heart; Angiogram - coronary

Definition

Coronary angiography is a procedure that uses a special dye (contrast material) and x-rays to see how blood flows through your heart.

How the Test is Performed

Coronary angiography is usually done in conjunction with

Before the test starts, you will be given a mild sedative to help you relax.

An area of your body, usually the arm or groin, is cleaned and numbed with a local anesthetic. An IV (intravenous) line will be inserted into the area. A thin hollow tube called a catheter is placed through the IV and carefully moved up into one of the heart's arteries. X-ray images help the doctor see where the catheter should be placed.

Once the catheter is in place, the dye (contrast material) is injected into the IV. X-ray images are taken to see how the dye moves through the artery. The dye helps highlight any blockages in blood flow.

How to Prepare for the Test

e the test starts. You may need to stay in the hospital the night before the test. Otherwise, you will check in to the hospital the morning of the test.

You will wear a hospital gown. You must sign a consent form before the test. Your health care provider will explain the procedure and its risks.

Tell your doctor if you are allergic to seafood, if you have had a bad reaction to contrast material in the past, if you are taking Viagra, or if you might be pregnant.

How the Test Will Feel

The procedure may last from 1 to several hours. You are awake during the test. You may feel some discomfort when the IV is placed into your arm and some pressure at the site when the catheter is inserted.

Occasionally, a flushing sensation occurs after the dye is injected.

After the test, the catheter is removed. You might feel a firm pressure at the insertion site, used to prevent bleeding. If the IV is placed in your groin, you will usually be asked to lie flat on your back for a few hours after the test to avoid bleeding. This may cause some mild back discomfort.

Why the Test is Performed

Coronary angiography is done to find a blockage in the coronary arteries, which can lead to heart attack. It may be done if you have unstable angina, atypical chest pain, aortic stenosis, or unexplained heart failure.

Normal Results Return to top

There is a normal supply of blood to the heart and no blockages.

What Abnormal Results Mean

An abnormal result may mean you have a blocked artery. The test can show how many coronary arteries are blocked, where they are blocked, and the severity of the blockage(s).

Risks

Cardiac catheterization carries a slightly increased risk when compared with other heart tests. However, the test is very safe when performed by an experienced team.

Generally the risk of serious complications ranges from 1 in 1,000 to 1 in 500. Risks of the procedure include the following:

Cardiac arrhythmias
Cardiac tamponade
Trauma to the artery caused by hematoma
Low blood pressure
Reaction to contrast medium
Hemorrhage
Stroke
Heart attack

Considerations associated with any type of catheterization include the following:

In general, there is a risk of bleeding, infection, and pain at the IV site.
There is always a very small risk that the soft plastic catheters could actually damage the blood vessels.
Blood clots could form on the catheters and later block blood vessels elsewhere in the body.
The contrast material could damage the kidneys (particularly in patients with diabetes).

Considerations

If a blockage is found, your health care provider may perform a percutaneous coronary intervention (PCI) to open the blockage. This can be done during the same procedure.

cpr

2007-12-29T10:58:00.001-08:00

Indications
1. Inadequate oxygenation (decreased arterial PO2, etc.) that is not corrected by supplemental oxygen supplied by mask or nasal prongs.
2. Inadequate ventilation (increased arterial PCO2).
3. Need to control and remove pulmonary secretions (bronchial toilet).
4. Need to provide airway protection in an obtunded patient or a patient with a depressed gag reflex (for example during a general anesthesia).
Contraindications
The following are only relative contraindications to tracheal intubation:
1. Severe airway trauma or obstruction that does not permit safe passage of an endotracheal tube. Emergency cricothyrotomy is indicated in such cases.
2. Cervical spine injury, in which the need for complete immobilization of the cervical spine makes endotracheal intubation difficult.
Preparing the Procedure
When intubating a patient, there are certain bare essentials that must be present to ensure a safe intubation. They can be remembered by the mnemonic SALT
Suction. This is extremely important. Often patients will have material in the pharynx, making visualization of the vocal cords difficult. Pulmonary Aspiration should be avoided.
Airway. the oral airway is a device that lifts the tongue off the posterior pharynx, often making it easier to mask ventilate a patient. The inability to ventilate a patient is bad. Also a source of O2 with a delivery mechanism (ambu-bag and mask) must be available.
Laryngoscope. This lighted tool is vital to placing an endotracheal tube.
Tube. Endotracheal tubes come in many sizes. In the average adult a size 7.0 or 8.0 oral endotracheal tube will work just fine.
Equipment Required
1. Self-refilling bag-valve combination (eg, Ambu bag) or bag-valve unit (Ayres bag), connector, tubing, and oxygen source. Assemble all items before attempting intubation.
2. Laryngoscope with curved (Macintosh type) and straight (Miller type) blades of a size appropriate for the patient.
3. Endotracheal tubes of several different sizes. Low-pressure, high-flow cuffed balloons are preferred.
4. Oral airways.
5. Tincture of benzoin and precut tape.
6. Introducer (stylets or Magill forceps).
7. Suction apparatus (tonsil tip and catheter suction).
8. Syringe, 10-mL, to inflate the cuff.
9. Mucosal anesthetics (eg, 2% lidocaine)
10. Water-soluble sterile lubricant.
11. Gloves.
Position of the patient
The height of the table where the patient is lied, should be adjusted so that the patient's face is at the level of the xiphoid cartilage of the standing person who is performing the procedure. Elevating the patient's head about 10 cm with pads under the occiput and extension of the head at the atlanto-occipital joint (sniffing position) serve to align the oral, pharyngeal, and laryngeal axis, so that the passage from the lips to the glottic opening is almost a straight line. This position permits better visualization of the glottis and vocal cords and allows easier passage of the endotracheal tube. For children under 1 month of age, the head should be in a neutral position. See Figure 1.
Figure 1:Letter A shows the wrong and letter B shows the correct position of patient's head.
Technique
A. Mask ventilation: (Oxygen delivered with a face mask at a rate of 10-15 L/min.):
1. Select the proper-sized mask; it should cover the mouth and nose and fit snugly against the cheeks.
2. Place the patient in the sniffing position.
3. Place the mask over the patient's mouth and nose with the right hand.
4. With the left hand, place the small and ring fingers under the patient's mandible, and lift up to open the airway. Grasp the mask with the thumb and index finger, and press it to the patient's face while lifting the mandible with the ring and small fingers.
5. Compress the bag with the right hand.
6.The chest should rise with each breath, and airflow should be unimpeded. If not, reposition the mask , and try again. Occasionally, insertion of an oral or nasal airway facilitates ventilation by mask. Because of the lack of support for the lips, elderly edentulous patients may be especially hard to ventilate using a mask.
B. Topical Anesthesia: Anesthetize the mucosa of the oropharynx, and upper airway with lidocaine 2%, if time permits and the patient is awake.
C. Direct Laryngoscopy:
1. Place the patient in the sniffing position.
2. Check the laryngoscope and blade for proper fit, and make sure that the light works.
3. Make sure that all materials are assembled and close at hand.
4. Curved blade technique:
a. Open the patient's mouth with the right hand, and remove any dentures.
b. Grasp the laryngoscope in the left hand as shown in Figure 2.
c. Spread the patient's lips, and insert the blade between the teeth, being careful not to break a tooth.
d. Pass the blade to the right of the tongue, and advance the blade into the hypopharynx, pushing the tongue to the left.
e. Lift the laryngoscope upward and forward, without changing the angle of the blade, to expose the vocal cords. See Figure3.
Figure 2:Technique of direct laryngoscopy and orotracheal intubation.
Figure 3:Curved blade placement in orotracheal intubation.
5. Straight blade technique:
Follow the steps outlined for curved blade technique, but advance the blade down the hypopharynx, and lift the epiglottis with the tip of the blade to expose the vocal cords. The tip of the laryngoscope blade fits below the epiglottis, which is no longer visible with the blade in position.See Figure 4.
Figure 4:Straight blade placement in orotracheal intubation.
D. Orotracheal Intubation:
1. Select the proper-sized tube.
2. With the 10-mL syringe, inflate the balloon with 5-8 mL of air. Make sure that the balloon is functional and intact.
3. Lubricate the end of the tube (optional).
4. Insert the stylet, and bend the tube and stylet gently into a crescent shape so that the tip of the stylet is at least 1 cm proximal to the end of the tube.
5. Ventilate the patient with the bag-valve combination for 1-2 minutes with 100% oxygen.
6. Proced the direct laryngoscopy (as explained above), and when visualizing the glottis and vocal cords (Figure 5), gently pass the tube next the laryngoscope blade through the vocal cords into trachea, far enough so that the balloon is just beyond the cords. Occasionally, gently pressing posteriorly on the anterior neck at the level of the larynx will help to bring an anteriorly placed larynx into view and facilitate intubation.
7. Withdraw the stylet.
8. Connect the bag-valve combination, and begin ventilation with 100% oxygen.
9. Confirm that the tube is properly positioned. First, listen over the stomach with a stethoscope while ventilating the patient. If sounds of airflow are heard or if distension of the stomach occurs, the tube is in the esophagus. If the esophagus has been intubated instead of the trachea, remove the tube and try again.
10. Listen to each side of the chest, be sure that breath sounds are equal in both sides of the thorax. If not, reposition the tube. When breath sounds are equal on both sides and the thorax rises equally on both sides with each inspiration, note the position of the tube (mark the tube at patient's mouth), and inflate the cuff with the 10-mL syringe until there is no air leak around the tube when positive pressure is applied.
11. Apply tincture of benzoin to the cheeks, upper lip, and endotracheal tube.
12. Wrap adhesive tape around the tube where it comes out of the mouth. Then carry the tape over the cheek and around the back of the head onto the other cheek. Fasten the end of the tape around the tube.
13. Obtain a chest x-ray film immediately to check tube placement, and also obtain arterial blood gas measurements to assess the adequacy of ventilation.

ecg simulator

2007-12-29T02:14:00.000-08:00

cadaver dissection room and videos

2007-12-28T05:30:00.000-08:00

heart animation

2007-12-17T12:07:00.000-08:00

Actinic Keratosis

2007-12-16T06:37:00.000-08:00

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Acne animation

2007-12-16T06:35:00.000-08:00

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Alzheimers Disease

2007-12-09T12:26:00.001-08:00

Alzheimer's Disease Fact Sheet

Introduction

Dementia is a brain disorder that seriously affects a person’s ability to carry out daily activities. The most common form of dementia among older people is Alzheimer’s disease (AD), which initially involves the parts of the brain that control thought, memory, and language. Although scientists are learning more every day, right now they still do not know what causes AD, and there is no cure.

Scientists think that as many as 4.5 million Americans suffer from AD. The disease usually begins after age 60, and risk goes up with age. While younger people also may get AD, it is much less common. About 5 percent of men and women ages 65 to 74 have AD, and nearly half of those age 85 and older may have the disease. It is important to note, however, that AD is not a normal part of aging.

AD is named after Dr. Alois Alzheimer, a German doctor. In 1906, Dr. Alzheimer noticed changes in the brain tissue of a woman who had died of an unusual mental illness. He found abnormal clumps (now called amyloid plaques) and tangled bundles of fibers (now called neurofibrillary tangles). Today, these plaques and tangles in the brain are considered signs of AD.

Scientists also have found other brain changes in people with AD. Nerve cells die in areas of the brain that are vital to memory and other mental abilities, and connections between nerve cells are disrupted. There also are lower levels of some of the chemicals in the brain that carry messages back and forth between nerve cells. AD may impair thinking and memory by disrupting these messages.
What Causes AD?

Scientists do not yet fully understand what causes AD. There probably is not one single cause, but several factors that affect each person differently. Age is the most important known risk factor for AD. The number of people with the disease doubles every 5 years beyond age 65.

Family history is another risk factor. Scientists believe that genetics may play a role in many AD cases. For example, early-onset familial AD, a rare form of AD that usually occurs between the ages of 30 and 60, is inherited. The more common form of AD is known as late-onset. It occurs later in life, and no obvious inheritance pattern is seen in most families. However, several risk factor genes may interact with each other and with non-genetic factors to cause the disease. The only risk factor gene identified so far for late-onset AD is a gene that makes one form of a protein called apolipoprotein E (ApoE). Everyone has ApoE, which helps carry cholesterol in the blood. Only about 15 percent of people have the form that increases the risk of AD. It is likely that other genes also may increase the risk of AD or protect against AD, but they remain to be discovered.

Scientists still need to learn a lot more about what causes AD. In addition to genetics and ApoE, they are studying education, diet, and environment to learn what role they might play in the development of this disease. Scientists are finding increasing evidence that some of the risk factors for heart disease and stroke, such as high blood pressure, high cholesterol, and low levels of the vitamin folate, may also increase the risk of AD. Evidence for physical, mental, and social activities as protective factors against AD is also increasing.

What Are the Symptoms of AD?

AD begins slowly. At first, the only symptom may be mild forgetfulness, which can be confused with age-related memory change. Most people with mild forgetfulness do not have AD. In the early stage of AD, people may have trouble remembering recent events, activities, or the names of familiar people or things. They may not be able to solve simple math problems. Such difficulties may be a bother, but usually they are not serious enough to cause alarm.

However, as the disease goes on, symptoms are more easily noticed and become serious enough to cause people with AD or their family members to seek medical help. Forgetfulness begins to interfere with daily activities. People in the middle stages of AD may forget how to do simple tasks like brushing their teeth or combing their hair. They can no longer think clearly. They can fail to recognize familiar people and places. They begin to have problems speaking, understanding, reading, or writing. Later on, people with AD may become anxious or aggressive, or wander away from home. Eventually, patients need total care.

How is AD Diagnosed?

An early, accurate diagnosis of AD helps patients and their families plan for the future. It gives them time to discuss care while the patient can still take part in making decisions. Early diagnosis will also offer the best chance to treat the symptoms of the disease.

Today, the only definite way to diagnose AD is to find out whether there are plaques and tangles in brain tissue. To look at brain tissue, however, doctors usually must wait until they do an autopsy, which is an examination of the body done after a person dies. Therefore, doctors can only make a diagnosis of “possible” or “probable” AD while the person is still alive.

At specialized centers, doctors can diagnose AD correctly up to 90 percent of the time. Doctors use several tools to diagnose “probable” AD, including:

* questions about the person’s general health, past medical problems, and ability to carry out daily activities,
* tests of memory, problem solving, attention, counting, and language,
* medical tests—such as tests of blood, urine, or spinal fluid, and
* brain scans.

Sometimes these test results help the doctor find other possible causes of the person’s symptoms. For example, thyroid problems, drug reactions, depression, brain tumors, and blood vessel disease in the brain can cause AD-like symptoms. Some of these other conditions can be treated successfully.

How is AD Treated?

AD is a slow disease, starting with mild memory problems and ending with severe brain damage. The course the disease takes and how fast changes occur vary from person to person. On average, AD patients live from 8 to 10 years after they are diagnosed, though some people may live with AD for as many as 20 years.

No treatment can stop AD. However, for some people in the early and middle stages of the disease, the drugs tacrine (Cognex, which is still available but no longer actively marketed by the manufacturer), donepezil (Aricept), rivastigmine (Exelon), or galantamine (Razadyne, previously known as Reminyl) may help prevent some symptoms from becoming worse for a limited time. Another drug, memantine (Namenda), has been approved to treat moderate to severe AD, although it also is limited in its effects. Also, some medicines may help control behavioral symptoms of AD such as sleeplessness, agitation, wandering, anxiety, and depression. Treating these symptoms often makes patients more comfortable and makes their care easier for caregivers.

New Areas of Research

The National Institute on Aging (NIA), part of the National Institutes of Health (NIH), is the lead Federal agency for AD research. NIA-supported scientists are testing a number of drugs to see if they prevent AD, slow the disease, or help reduce symptoms. Researchers undertake clinical trials to learn whether treatments that appear promising in observational and animal studies actually are safe and effective in people. Some ideas that seem promising turn out to have little or no benefit when they are carefully studied in a clinical trial.

Neuroimaging. Scientists are finding that damage to parts of the brain involved in memory, such as the hippocampus, can sometimes be seen on brain scans before symptoms of the disease occur. An NIA public-private partnership—the AD Neuroimaging Initiative (ADNI)—is a large study that will determine whether magnetic resonance imaging (MRI) and positron emission tomography (PET) scans, or other imaging or biological markers, can see early AD changes or measure disease progression. The project is designed to help speed clinical trials and find new ways to determine the effectiveness of treatments. For more information on ADNI, call the NIA’s Alzheimer’s Disease Education and Referral (ADEAR) Center at 1-800-438-4380, or visit www.alzheimers.nia.nih.gov.

AD Genetics. The NIA is sponsoring the AD Genetics Study to learn more about risk factor genes for late onset AD. To participate in this study, families with two or more living siblings diagnosed with AD should contact the National Cell Repository for AD toll-free at 1-800-526-2839. Information may also be requested through the study’s website: http://ncrad.iu.edu.

Mild Cognitive Impairment. During the past several years, scientists have focused on a type of memory change called mild cognitive impairment (MCI), which is different from both AD and normal age-related memory change. People with MCI have ongoing memory problems, but they do not have other losses such as confusion, attention problems, and difficulty with language. The NIA-funded Memory Impairment Study compared donepezil, vitamin E, or placebo in participants with MCI to see whether the drugs might delay or prevent progression to AD. The study found that the group with MCI taking donepezil were at reduced risk of progressing to AD for the first 18 months of a 3-year study, when compared with their counterparts on placebo. The reduced risk of progressing from MCI to a diagnosis of AD among participants on donepezil disappeared after 18 months, and by the end of the study, the probability of progressing to AD was the same in the two groups. Vitamin E had no effect at any time point in the study when compared with placebo.

Inflammation. There is evidence that inflammation in the brain may contribute to AD damage. Some studies have suggested that drugs such as nonsteroidal anti-inflammatory drugs (NSAIDs) might help slow the progression of AD, but clinical trials thus far have not demonstrated a benefit from these drugs. A clinical trial studying two of these drugs, rofecoxib (Vioxx) and naproxen (Aleve) showed that they did not delay the progression of AD in people who already have the disease. Another trial, testing whether the NSAIDs celecoxib (Celebrex) and naproxen could prevent AD in healthy older people at risk of the disease was suspended due to concerns over possible cardiovascular risk. Researchers are continuing to look for ways to test how other anti-inflammatory drugs might affect the development or progression of AD.

Antioxidants. Several years ago, a clinical trial showed that vitamin E slowed the progress of some consequences of AD by about 7 months. Additional studies are investigating whether antioxidants—vitamins E and C—can slow AD. Another clinical trial is examining whether vitamin E and/or selenium supplements can prevent AD or cognitive decline, and additional studies on other antioxidants are ongoing or being planned, including a study of the antioxidant treatments—vitamins E, C, alpha-lipoic acid, and coenzyme Q—in patients with mild to moderate AD.

Ginkgo biloba. Early studies suggested that extracts from the leaves of the ginkgo biloba tree may be of some help in treating AD symptoms. There is no evidence yet that ginkgo biloba will cure or prevent AD, but scientists now are trying to find out in a clinical trial whether ginkgo biloba can delay cognitive decline or prevent dementia in older people.

Estrogen. Some studies have suggested that estrogen used by women to treat the symptoms of menopause also protects the brain. Experts also wondered whether using estrogen could reduce the risk of AD or slow the disease. Clinical trials to test estrogen, however, have not shown that estrogen can slow the progression of already diagnosed AD. And one study found that women over the age of 65 who used estrogen with a progestin were at greater risk of dementia, including AD, and that older women using only estrogen could also increase their chance of developing dementia.

Scientists believe that more research is needed to find out if estrogen may play some role in AD. They would like to know whether starting estrogen therapy around the time of menopause, rather than at age 65 or older, will protect memory or prevent AD.

Participating in Clinical Trials

People with AD, those with MCI, or those with a family history of AD, who want to help scientists test possible treatments may be able to take part in clinical trials. Healthy people also can help scientists learn more about the brain and AD. The NIA maintains the AD Clinical Trials Database, which lists AD clinical trials sponsored by the Federal government and private companies. To find out more about these studies, contact the NIA’s ADEAR Center at 1-800-438-4380 or visit the ADEAR Center website at www.nia.nih.gov/Alzheimers/ResearchInformation/ClinicalTrials. You also can sign up for e-mail alerts on new clinical trials as they are added to the database. Additional clinical trials information is available at www.clinicaltrials.gov.

Many of these studies are being done at NIA-supported Alzheimer’s Disease Centers located throughout the United States. These centers carry out a wide range of research, including studies of the causes, diagnosis, treatment, and management of AD. To get a list of these centers, contact the ADEAR Center.
Advancing Our Understanding

Scientists have come a long way in their understanding of AD. Findings from years of research have begun to clarify differences between normal age-related memory changes, MCI, and AD. Scientists also have made great progress in defining the changes that take place in the AD brain, which allows them to pinpoint possible targets for treatment.
These advances are the foundation for the NIH Alzheimer’s Disease Prevention Initiative, which is designed to:

* understand why AD occurs and who is at greatest risk of developing it,
* improve the accuracy of diagnosis and the ability to identify those at risk,
* discover, develop, and test new treatments, and

discover treatments for behavioral problems in patients with AD.
Is There Help for Caregivers?

Most often, spouses and other family members provide the day-to-day care for people with AD. As the disease gets worse, people often need more and more care. This can be hard for caregivers and can affect their physical and mental health, family life, job, and finances.

The Alzheimer’s Association has chapters nationwide that provide educational programs and support groups for caregivers and family members of people with AD. Contact information for the Alzheimer’s Association is listed at the end of this fact sheet.

Alzheimer's disease (AD) is the most common form of dementia among older people. Dementia is a brain disorder that seriously affects a person's ability to carry out daily activities.

AD begins slowly. It first involves the parts of the brain that control thought, memory and language. People with AD may have trouble remembering things that happened recently or names of people they know. Over time, symptoms get worse. People may not recognize family members or have trouble speaking, reading or writing. They may forget how to brush their teeth or comb their hair. Later on, they may become anxious or aggressive, or wander away from home. Eventually, they need total care. This can cause great stress for family members who must care for them.

AD usually begins after age 60. The risk goes up as you get older. Your risk is also higher if a family member has had the disease.

No treatment can stop the disease. However, some drugs may help keep symptoms from getting worse for a limited time.

Examination of Eyes and Ears

2007-12-09T12:25:00.003-08:00

the HEENT, or Head, Eye, Ear, Nose and Throat Exam is usually the initial part of a general physical exam, after the vital signs. Like other exam it begins with inspection, and then proceeds to palpation. It requires the use of several special instruments in order to inspect the eyes and ears, and special techniques to assess their special sensory function. This Physical diagnostic movies reviews some of the relevant surface anatomy and describes the basic HEENT exam.

ntroduction

For 2 years, Jim suffered the excruciating pain of cluster headaches. Night after night he paced the floor, the pain driving him to constant motion. He was only 48 years old when the clusters forced him to quit his job as a systems analyst. One year later, his headaches are controlled. The credit for Jim's recovery belongs to the medical staff of a headache clinic. Physicians there applied the latest research findings on headache, and prescribed for Jim a combination of new drugs.

Joan was a victim of frequent migraine. Her headaches lasted 2 days. Nauseous and weak, she stayed in the dark until each attack was over. Today, although migraine still interferes with her life, she has fewer attacks and less severe headaches than before. A specialist prescribed an antimigraine program for Joan that included improved drug therapy, a new diet and relaxation training.

An avid reader, Peggy couldn't put down the new mystery thriller. After 4 hours of reading slumped in bed, she knew she had overdone it. Her tensed head and neck muscles felt as if they were being squeezed between two giant hands. But for Peggy, the muscle-contraction headache and neck pain were soon relieved by a hot shower and aspirin.

Understanding why headaches occur and improving headache treatment are among the research goals of the National Institute of Neurological Disorders and Stroke (NINDS). As the leading supporter of brain research in the Federal Government, the NINDS also supports and conducts studies to improve the diagnosis of headaches and to find ways to prevent them.
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Why Does it Hurt?

What hurts when you have a headache? The bones of the skull and tissues of the brain itself never hurt, because they lack pain-sensitive nerve fibers. Several areas of the head can hurt, including a network of nerves which extends over the scalp and certain nerves in the face, mouth, and throat. Also sensitive to pain, because they contain delicate nerve fibers, are the muscles of the head and blood vessels found along the surface and at the base of the brain.

The ends of these pain-sensitive nerves, called nociceptors, can be stimulated by stress, muscular tension, dilated blood vessels, and other triggers of headache. Once stimulated, a nociceptor sends a message up the length of the nerve fiber to the nerve cells in the brain, signaling that a part of the body hurts. The message is determined by the location of the nociceptor. A person who suddenly realizes "My toe hurts," is responding to nociceptors in the foot that have been stimulated by the stubbing of a toe.

A number of chemicals help transmit pain-related information to the brain. Some of these chemicals are natural painkilling proteins called endorphins, Greek for "the morphine within." One theory suggests that people who suffer from severe headache and other types of chronic pain have lower levels of endorphins than people who are generally pain free.
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When Should You See a Physician?

Not all headaches require medical attention. Some result from missed meals or occasional muscle tension and are easily remedied. But some types of headache are signals of more serious disorders, and call for prompt medical care. These include:

* Sudden, severe headache
* Sudden, severe headache associated with a stiff neck
* Headache associated with fever
* Headache associated with convulsions
* Headache accompanied by confusion or loss of consciousness
* Headache following a blow on the head
* Headache associated with pain in the eye or ear
* Persistent headache in a person who was previously headache free
* Recurring headache in children
* Headache which interferes with normal life

A headache sufferer usually seeks help from a family practitioner. If the problem is not relieved by standard treatments, the patient may then be referred to a specialist - perhaps an internist or neurologist. Additional referrals may be made to psychologists.
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What Tests Are Used to Diagnose Headache?

Diagnosing a headache is like playing Twenty Questions. Experts agree that a detailed question-and-answer session with a patient can often produce enough information for a diagnosis. Many types of headaches have clear-cut symptoms which fall into an easily recognizable pattern.

Patients may be asked: How often do you have headaches? Where is the pain? How long do the headaches last? When did you first develop headaches? The patient's sleep habits and family and work situations may also be probed.

Most physicians will also obtain a full medical history from the patient, inquiring about past head trauma or surgery, eye strain, sinus problems, dental problems, difficulties with opening and closing of the jaw, and the use of medications. This may be enough to suggest strongly that the patient has migraine or cluster headaches. A complete and careful physical and neurological examination will exclude many possibilities and the suspicion of aneurysm, meningitis, or certain brain tumors. A blood test may be ordered to screen for thyroid disease, anemia, or infections which might cause a headache.

A test called an electroencephalogram (EEG) may be given to measure brain activity. EEG's can indicate a malfunction in the brain, but they cannot usually pinpoint a problem that might be causing a headache. A physician may suggest that a patient with unusual headaches undergo a computed tomographic (CT) scan and/or a magnetic resonance imaging (MRI) scan. The scans enable the physician to distinguish, for example, between a bleeding blood vessel in the brain and a brain tumor, and are important diagnostic tools in cases of headache associated with brain lesions or other serious disease. CT scans produce X-ray images of the brain that show structures or variations in the density of different types of tissue. MRI scans use magnetic fields and radio waves to produce an image that provides information about the structure and biochemistry of the brain.

If an aneurysm-an abnormal ballooning of a blood vessel-is suspected, a physician may order a CT scan to examine for blood and then an angiogram. In this test, a special fluid which can be seen on an X-ray is injected into the patient and carried in the bloodstream to the brain to reveal any abnormalities in the blood vessels there.

A physician analyzes the results of all these diagnostic tests along with a patient's medical history and examination in order to arrive at a diagnosis.

Headaches are diagnosed as

* Vascular
* Muscle contraction (tension)
* Traction
* Inflammatory

Vascular headaches - a group that includes the well-known migraine - are so named because they are thought to involve abnormal function of the brain's blood vessels or vascular system. Muscle contraction headaches appear to involve the tightening or tensing of facial and neck muscles. Traction and inflammatory headaches are symptoms of other disorders, ranging from stroke to sinus infection. Some people have more than one type of headache.
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What Are Migraine Headaches?

The most common type of vascular headache is migraine. Migraine headaches are usually characterized by severe pain on one or both sides of the head, an upset stomach, and at times disturbed vision.

Former basketball star Kareem Abdul-Jabbar remembers experiencing his first migraine at age 14. The pain was unlike the discomfort of his previous mild headaches.

"When I got this one I thought, 'This is a headache'," he says. "The pain was intense and I felt nausea and a great sensitivity to light. All I could think about was when it would stop. I sat in a dark room for an hour and it passed."

Symptoms of migraine. Abdul-Jabbar's sensitivity to light is a standard symptom of the two most prevalent types of migraine-caused headache: classic and common.

The major difference between the two types is the appearance of neurological symptoms 10 to 30 minutes before a classic migraine attack. These symptoms are called an aura. The person may see flashing lights or zigzag lines, or may temporarily lose vision. Other classic symptoms include speech difficulty, weakness of an arm or leg, tingling of the face or hands, and confusion.

The pain of a classic migraine headache may be described as intense, throbbing, or pounding and is felt in the forehead, temple, ear, jaw, or around the eye. Classic migraine starts on one side of the head but may eventually spread to the other side. An attack lasts 1 to 2 pain-wracked days.

Common migraine - a term that reflects the disorder's greater occurrence in the general population - is not preceded by an aura. But some people experience a variety of vague symptoms beforehand, including mental fuzziness, mood changes, fatigue, and unusual retention of fluids. During the headache phase of a common migraine, a person may have diarrhea and increased urination, as well as nausea and vomiting. Common migraine pain can last 3 or 4 days.

Both classic and common migraine can strike as often as several times a week, or as rarely as once every few years. Both types can occur at any time. Some people, however, experience migraines at predictable times - for example, near the days of menstruation or every Saturday morning after a stressful week of work.

The migraine process. Research scientists are unclear about the precise cause of migraine headaches. There seems to be general agreement, however, that a key element is blood flow changes in the brain. People who get migraine headaches appear to have blood vessels that overreact to various triggers.

Scientists have devised one theory of migraine which explains these blood flow changes and also certain biochemical changes that may be involved in the headache process. According to this theory, the nervous system responds to a trigger such as stress by causing a spasm of the nerve-rich arteries at the base of the brain. The spasm closes down or constricts several arteries supplying blood to the brain, including the scalp artery and the carotid or neck arteries.

As these arteries constrict, the flow of blood to the brain is reduced. At the same time, blood-clotting particles called platelets clump together-a process which is believed to release a chemical called serotonin. Serotonin acts as a powerful constrictor of arteries, further reducing the blood supply to the brain.

Reduced blood flow decreases the brain's supply of oxygen. Symptoms signaling a headache, such as distorted vision or speech, may then result, similar to symptoms of stroke.

Reacting to the reduced oxygen supply, certain arteries within the brain open wider to meet the brain's energy needs. This widening or dilation spreads, finally affecting the neck and scalp arteries. The dilation of these arteries triggers the release of pain-producing substances called prostaglandins from various tissues and blood cells. Chemicals which cause inflammation and swelling, and substances which increase sensitivity to pain, are also released. The circulation of these chemicals and the dilation of the scalp arteries stimulate the pain-sensitive nociceptors. The result, according to this theory: a throbbing pain in the head.

Women and migraine. Although both males and females seem to be equally affected by migraine, the condition is more common in adult women. Both sexes may develop migraine in infancy, but most often the disorder begins between the ages of 5 and 35.

The relationship between female hormones and migraine is still unclear. Women may have "menstrual migraine" - headaches around the time of their menstrual period - which may disappear during pregnancy. Other women develop migraine for the first time when they are pregnant. Some are first affected after menopause.

The effect of oral contraceptives on headaches is perplexing. Scientists report that some women with migraine who take birth control pills experience more frequent and severe attacks. However, a small percentage of women have fewer and less severe migraine headaches when they take birth control pills. And normal women who do not suffer from headaches may develop migraines as a side effect when they use oral contraceptives. Investigators around the world are studying hormonal changes in women with migraine in the hope of identifying the specific ways these naturally occurring chemicals cause headaches.

Triggers of headache. Although many sufferers have a family history of migraine, the exact hereditary nature of this condition is still unknown. People who get migraines are thought to have an inherited abnormality in the regulation of blood vessels.

"It's like a cocked gun with a hair trigger," explains one specialist. "A person is born with a potential for migraine and the headache is triggered by things that are really not so terrible."

These triggers include stress and other normal emotions, as well as biological and environmental conditions. Fatigue, glaring or flickering lights, changes in the weather, and certain foods can set off migraine. It may seem hard to believe that eating such seemingly harmless foods as yogurt, nuts, and lima beans can result in a painful migraine headache. However, some scientists believe that these foods and several others contain chemical substances, such as tyramine, which constrict arteries - the first step of the migraine process. Other scientists believe that foods cause headaches by setting off an allergic reaction in susceptible people.

While a food-triggered migraine usually occurs soon after eating, other triggers may not cause immediate pain. Scientists report that people can develop migraine not only during a period of stress but also afterwards when their vascular systems are still reacting. For example, migraines that wake people up in the middle of the night are believed to result from a delayed reaction to stress.

Other forms of migraine. In addition to classic and common, migraine headache can take several other forms:

Patients with hemiplegic migraine have temporary paralysis on one side of the body, a condition known as hemiplegia. Some people may experience vision problems and vertigo - a feeling that the world is spinning. These symptoms begin 10 to 90 minutes before the onset of headache pain.

In ophthalmoplegic migraine, the pain is around the eye and is associated with a droopy eyelid, double vision, and other problems with vision.

Basilar artery migraine involves a disturbance of a major brain artery at the base of the brain. Preheadache symptoms include vertigo, double vision, and poor muscular coordination. This type of migraine occurs primarily in adolescent and young adult women and is often associated with the menstrual cycle.

Benign exertional headache is brought on by running, lifting, coughing, sneezing, or bending. The headache begins at the onset of activity, and pain rarely lasts more than several minutes.

Status migrainosus is a rare and severe type of migraine that can last 72 hours or longer. The pain and nausea are so intense that people who have this type of headache must be hospitalized. The use of certain drugs can trigger status migrainosus. Neurologists report that many of their status migrainosus patients were depressed and anxious before they experienced headache attacks.

Headache-free migraine is characterized by such migraine symptoms as visual problems, nausea, vomiting, constipation, or diarrhea. Patients, however, do not experience head pain. Headache specialists have suggested that unexplained pain in a particular part of the body, fever, and dizziness could also be possible types of headache-free migraine.
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How is Migraine Headache Treated?

During the Stone Age, pieces of a headache sufferer's skull were cut away with flint instruments to relieve pain. Another unpleasant remedy used in the British Isles around the ninth Century involved drinking "the juice of elderseed, cow's brain, and goat's dung dissolved in vinegar." Fortunately, today's headache patients are spared such drastic measures.

Drug therapy, biofeedback training, stress reduction, and elimination of certain foods from the diet are the most common methods of preventing and controlling migraine and other vascular headaches. Joan, the migraine sufferer, was helped by treatment with a combination of an antimigraine drug and diet control.

Regular exercise, such as swimming or vigorous walking, can also reduce the frequency and severity of migraine headaches. Joan found that whirlpool and yoga baths helped her relax.

During a migraine headache, temporary relief can sometimes be obtained by applying cold packs to the head or by pressing on the bulging artery found in front of the ear on the painful side of the head.

Drug therapy. There are two ways to approach the treatment of migraine headache with drugs: prevent the attacks, or relieve symptoms after the headache occurs.

For infrequent migraine, drugs can be taken at the first sign of a headache in order to stop it or to at least ease the pain. People who get occasional mild migraine may benefit by taking aspirin or acetaminophen at the start of an attack. Aspirin raises a person's tolerance to pain and also discourages clumping of blood platelets. Small amounts of caffeine may be useful if taken in the early stages of migraine. But for most migraine sufferers who get moderate to severe headaches, and for all cluster headache patients (see section "Besides Migraine, What Are Other Types of Vascular Headaches?"), stronger drugs may be necessary to control the pain.

Several drugs for the prevention of migraine have been developed in recent years, including serotonin agonists which mimic the action of this key brain chemical. One of the most commonly used drugs for the relief of classic and common migraine symptoms is sumatriptan, which binds to serotonin receptors. For optimal benefit, the drug is taken during the early stages of an attack. If a migraine has been in progress for about an hour after the drug is taken, a repeat dose can be given.

Physicians caution that sumatriptan should not be taken by people who have angina pectoris, basilar migraine, severe hypertension, or vascular, or liver disease.

Another migraine drug is ergotamine tartrate, a vasoconstrictor which helps counteract the painful dilation stage of the headache. Other drugs that constrict dilated blood vessels or help reduce blood vessel inflammation also are available.

For headaches that occur three or more times a month, preventive treatment is usually recommended. Drugs used to prevent classic and common migraine include methysergide maleate, which counteracts blood vessel constriction; propranolol hydrochloride, which stops blood vessel dilation; amitriptyline, an antidepressant; valproic acid, an anticonvulsant; and verapamil, a calcium channel blocker.

Antidepressants called MAO inhibitors also prevent migraine. These drugs block an enzyme called monoamine oxidase which normally helps nerve cells absorb the artery-constricting brain chemical, serotonin. MAO inhibitors can have potentially serious side effects - particularly if taken while ingesting foods or beverages that contain tyramine, a substance that constricts arteries.

Many antimigraine drugs can have adverse side effects. But like most medicines they are relatively safe when used carefully and under a physician's supervision. To avoid long-term side effects of preventive medications, headache specialists advise patients to reduce the dosage of these drugs and then stop taking them as soon as possible.

Biofeedback and relaxation training. Drug therapy for migraine is often combined with biofeedback and relaxation training. Biofeedback refers to a technique that can give people better control over such body function indicators as blood pressure, heart rate, temperature, muscle tension, and brain waves. Thermal biofeedback allows a patient to consciously raise hand temperature. Some patients who are able to increase hand temperature can reduce the number and intensity of migraines. The mechanisms underlying these self-regulation treatments are being studied by research scientists.

"To succeed in biofeedback," says a headache specialist, "you must be able to concentrate and you must be motivated to get well."

A patient learning thermal biofeedback wears a device which transmits the temperature of an index finger or hand to a monitor. While the patient tries to warm his hands, the monitor provides feedback either on a gauge that shows the temperature reading or by emitting a sound or beep that increases in intensity as the temperature increases. The patient is not told how to raise hand temperature, but is given suggestions such as "Imagine your hands feel very warm and heavy."

"I have a good imagination," says one headache sufferer who traded in her medication for thermal biofeedback. The technique decreased the number and severity of headaches she experienced.

In another type of biofeedback called electromyographic or EMG training, the patient learns to control muscle tension in the face, neck, and shoulders.

Either kind of biofeedback may be combined with relaxation training, during which patients learn to relax the mind and body.

Biofeedback can be practiced at home with a portable monitor. But the ultimate goal of treatment is to wean the patient from the machine. The patient can then use biofeedback anywhere at the first sign of a headache.

The antimigraine diet. Scientists estimate that a small percentage of migraine sufferers will benefit from a treatment program focused solely on eliminating headache-provoking foods and beverages.

Other migraine patients may be helped by a diet to prevent low blood sugar. Low blood sugar, or hypoglycemia, can cause headache. This condition can occur after a period without food: overnight, for example, or when a meal is skipped. People who wake up in the morning with a headache may be reacting to the low blood sugar caused by the lack of food overnight.

Treatment for headaches caused by low blood sugar consists of scheduling smaller, more frequent meals for the patient. A special diet designed to stabilize the body's sugar-regulating system is sometimes recommended.

For the same reason, many specialists also recommend that migraine patients avoid oversleeping on weekends. Sleeping late can change the body's normal blood sugar level and lead to a headache.
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Besides Migraine, What Are Other Types of Vascular Headaches?

After migraine, the most common type of vascular headache is the toxic headache produced by fever. Pneumonia, measles, mumps, and tonsillitis are among the diseases that can cause severe toxic vascular headaches. Toxic headaches can also result from the presence of foreign chemicals in the body. Other kinds of vascular headaches include "clusters," which cause repeated episodes of intense pain, and headaches resulting from a rise in blood pressure.

Chemical culprits. Repeated exposure to nitrite compounds can result in a dull, pounding headache that may be accompanied by a flushed face. Nitrite, which dilates blood vessels, is found in such products as heart medicine and dynamite, but is also used as a chemical to preserve meat. Hot dogs and other processed meats containing sodium nitrite can cause headaches.

Eating foods prepared with monosodium glutamate (MSG) can result in headache. Soy sauce, meat tenderizer, and a variety of packaged foods contain this chemical which is touted as a flavor enhancer.

Headache can also result from exposure to poisons, even common household varieties like insecticides, carbon tetrachloride, and lead. Children who ingest flakes of lead paint may develop headaches. So may anyone who has contact with lead batteries or lead-glazed pottery.

Artists and industrial workers may experience headaches after exposure to materials that contain chemical solvents. These solvents, like benzene, are found in turpentine, spray adhesives, rubber cement, and inks.

Drugs such as amphetamines can cause headaches as a side effect. Another type of drug-related headache occurs during withdrawal from long-term therapy with the antimigraine drug ergotamine tartrate.

Jokes are often made about alcohol hangovers but the headache associated with "the morning after" is no laughing matter. Fortunately, there are several suggested treatments for the pain. The hangover headache may also be reduced by taking honey, which speeds alcohol metabolism, or caffeine, a constrictor of dilated arteries. Caffeine, however, can cause headaches as well as cure them. Heavy coffee drinkers often get headaches when they try to break the caffeine habit.

Cluster headaches. Cluster headaches are a rare form of headache notable for their extreme pain and their pattern of occurring in "clusters", usually at the same time(s) of the day for several weeks. A cluster headache usually begins suddenly with excruciating pain on one side of the head, often behind or around one eye. In some individuals, it may be preceded by a migraine-like "aura." The pain usually peaks over the next 5 to 10 minutes, and then continues at that intensity for up to an hour or two before going away.

People with cluster headaches describe the pain as piercing and unbearable. The nose and the eye on the affected side of the face may also get red, swollen, and runny, and some people will experience nausea, restlessness and agitation, or sensitivities to light, sound, or smell. Most affected individuals have one to three cluster headaches a day and two cluster periods a year, separated by periods of freedom from symptoms.

A small group of people develop a chronic form of the disorder, characterized by bouts of cluster headaches that can go on for years with only brief periods (2 weeks or less) of remission.

Cluster headaches generally begin between the ages of 20 and 50, although the syndrome can also start in childhood or late in life. Males are much more likely than females to develop cluster headaches. Alcohol (especially red wine) provokes attacks in more than half of those with cluster headaches, but has no effect once the cluster period ends. Cluster headaches are also strongly associated with cigarette smoking.

Scientists aren't sure what causes the disorder. The tendency of cluster headaches to occur during the same time(s) from day to day, and more often at night than during the daylight hours, suggests they could be caused by irregularities in the body’s circadian rhythms, which are controlled by the brain and a family of hormones that regulate the sleep-wake cycle.

There are medications available to lessen the pain of a cluster headache and suppress future attacks. Oxygen inhalation and triptan drugs (such as those used to treat migraine) administered as a tablet, nasal spray, or injection can provide quick relief from acute cluster headache pain. Lidocaine nasal spray, which numbs the nose and nostrils, may also be effective. Ergotamine and corticosteroids such as prednisone and dexamethasone may be prescribed to break the cluster cycle and then tapered off once headaches end. Verapamil may be used preventively to decrease the frequency and pain level of attacks. Lithium, valproic acid, and topiramate are sometimes also used preventively.

Painful pressure . Chronic high blood pressure can cause headache, as can rapid rises in blood pressure like those experienced during anger, vigorous exercise, or sexual excitement.

The severe "orgasmic headache" occurs right before orgasm and is believed to be a vascular headache. Since sudden rupture of a cerebral blood vessel can occur, this type of headache should be evaluated by a doctor.
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What Are Muscle-Contraction Headaches?

It's 5:00 p.m. and your boss has just asked you to prepare a 20-page briefing paper. Due date: tomorrow. You're angry and tired and the more you think about the assignment, the tenser you become. Your teeth clench, your brow wrinkles, and soon you have a splitting tension headache.

Tension headache is named not only for the role of stress in triggering the pain, but also for the contraction of neck, face, and scalp muscles brought on by stressful events. Tension headache is a severe but temporary form of muscle-contraction headache. The pain is mild to moderate and feels like pressure is being applied to the head or neck. The headache usually disappears after the period of stress is over. Ninety percent of all headaches are classified as tension/muscle contraction headaches.

By contrast, chronic muscle-contraction headaches can last for weeks, months, and sometimes years. The pain of these headaches is often described as a tight band around the head or a feeling that the head and neck are in a cast. "It feels like somebody is tightening a giant vise around my head," says one patient. The pain is steady, and is usually felt on both sides of the head. Chronic muscle-contraction headaches can cause sore scalps - even combing one's hair can be painful.

In the past, many scientists believed that the primary cause of the pain of muscle-contraction headache was sustained muscle tension. However, a growing number of authorities now believe that a far more complex mechanism is responsible.

Occasionally, muscle-contraction headaches will be accompanied by nausea, vomiting, and blurred vision, but there is no preheadache syndrome as with migraine. Muscle-contraction headaches have not been linked to hormones or foods, as has migraine, nor is there a strong hereditary connection.

Research has shown that for many people, chronic muscle-contraction headaches are caused by depression and anxiety. These people tend to get their headaches in the early morning or evening when conflicts in the office or home are anticipated.

Emotional factors are not the only triggers of muscle-contraction headaches. Certain physical postures that tense head and neck muscles - such as holding one's chin down while reading - can lead to head and neck pain. So can prolonged writing under poor light, or holding a phone between the shoulder and ear, or even gum-chewing.

More serious problems that can cause muscle-contraction headaches include degenerative arthritis of the neck and temporomandibular joint dysfunction, or TMD. TMD is a disorder of the joint between the temporal bone (above the ear) and the mandible or lower jaw bone. The disorder results from poor bite and jaw clenching.

Treatment for muscle-contraction headache varies. The first consideration is to treat any specific disorder or disease that may be causing the headache. For example, arthritis of the neck is treated with anti-inflammatory medication and TMD may be helped by corrective devices for the mouth and jaw.

Acute tension headaches not associated with a disease are treated with analgesics like aspirin and acetaminophen. Stronger analgesics, such as propoxyphene and codeine, are sometimes prescribed. As prolonged use of these drugs can lead to dependence, patients taking them should have periodic medical checkups and follow their physicians' instructions carefully.

Nondrug therapy for chronic muscle-contraction headaches includes biofeedback, relaxation training, and counseling. A technique called cognitive restructuring teaches people to change their attitudes and responses to stress. Patients might be encouraged, for example, to imagine that they are coping successfully with a stressful situation. In progressive relaxation therapy, patients are taught to first tense and then relax individual muscle groups. Finally, the patient tries to relax his or her whole body. Many people imagine a peaceful scene - such as lying on the beach or by a beautiful lake. Passive relaxation does not involve tensing of muscles. Instead, patients are encouraged to focus on different muscles, suggesting that they relax. Some people might think to themselves, Relax or My muscles feel warm.

People with chronic muscle-contraction headaches my also be helped by taking antidepressants or MAO inhibitors. Mixed muscle-contraction and migraine headaches are sometimes treated with barbiturate compounds, which slow down nerve function in the brain and spinal cord.

People who suffer infrequent muscle-contraction headaches may benefit from a hot shower or moist heat applied to the back of the neck. Cervical collars are sometimes recommended as an aid to good posture. Physical therapy, massage, and gentle exercise of the neck may also be helpful.
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When is Headache a Warning of a More Serious Condition?

Like other types of pain, headaches can serve as warning signals of more serious disorders. This is particularly true for headaches caused by traction or inflammation.

Traction headaches can occur if the pain-sensitive parts of the head are pulled, stretched, or displaced, as, for example, when eye muscles are tensed to compensate for eyestrain. Headaches caused by inflammation include those related to meningitis as well as those resulting from diseases of the sinuses, spine, neck, ears, and teeth. Ear and tooth infections and glaucoma can cause headaches. In oral and dental disorders, headache is experienced as pain in the entire head, including the face. These headaches are treated by curing the underlying problem. This may involve surgery, antibiotics, or other drugs.

Characteristics of the various types of more serious traction and inflammatory headaches vary by disorder:

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Brain tumor . As they grow, brain tumors sometimes cause headache by pushing on the outer layer of nerve tissue that covers the brain or by pressing against pain-sensitive blood vessel walls. Headache resulting from a brain tumor may be periodic or continuous. Typically, it feels like a strong pressure is being applied to the head. The pain is relieved when the tumor is treated by surgery, radiation, or chemotherapy.
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Stroke. Headache may accompany several conditions that can lead to stroke, including hypertension or high blood pressure, arteriosclerosis, and heart disease. Headaches are also associated with completed stroke, when brain cells die from lack of sufficient oxygen.

Many stroke-related headaches can be prevented by careful management of the patient's condition through diet, exercise, and medication.

Mild to moderate headaches are associated with transient ischemic attacks (TIA's), sometimes called "mini-strokes,"which result from a temporary lack of blood supply to the brain. The head pain occurs near the clot or lesion that blocks blood flow. The similarity between migraine and symptoms of TIA can cause problems in diagnosis. The rare person under age 40 who suffers a TIA may be misdiagnosed as having migraine; similarly, TIA-prone older patients who suffer migraine may be misdiagnosed as having stroke-related headaches.
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Spinal tap. About one-fourth of the people who undergo a lumbar puncture or spinal tap develop a headache. Many scientists believe these headaches result from leakage of the cerebrospinal fluid that flows through pain-sensitive membranes around the brain and down to the spinal cord. The fluid, they suggest, drains through the tiny hole created by the spinal tap needle, causing the membranes to rub painfully against the bony skull. Since headache pain occurs only when the patient stands up, the "cure" is to remain lying down until the headache runs its course - anywhere from a few hours to several days.
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Head trauma. Headaches may develop after a blow to the head, either immediately or months later. There is little relationship between the severity of the trauma and the intensity of headache pain. In most cases, the cause of the headache is not known. Occasionally the cause is ruptured blood vessels which result in an accumulation of blood called a hematoma. This mass of blood can displace brain tissue and cause headaches as well as weakness, confusion, memory loss, and seizures. Hematomas can be drained to produce rapid relief of symptoms.
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Temporal arteritis. Arteritis, an inflammation of certain arteries in the head, primarily affects people over age 50. Symptoms include throbbing headache, fever, and loss of appetite. Some patients experience blurring or loss of vision. Prompt treatment with corticosteroid drugs helps to relieve symptoms.
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Meningitis and encephalitis headaches are caused by infections of meninges-the brain's outer covering-and in encephalitis, inflammation of the brain itself.
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Trigeminal neuralgia. Trigeminal neuralgia, or tic douloureux, results from a disorder of the trigeminal nerve. This nerve supplies the face, teeth, mouth, and nasal cavity with feeling and also enables the mouth muscles to chew. Symptoms are headache and intense facial pain that comes in short, excruciating jabs set off by the slightest touch to or movement of trigger points in the face or mouth. People with trigeminal neuralgia often fear brushing their teeth or chewing on the side of the mouth that is affected. Many trigeminal neuralgia patients are controlled with drugs, including carbamazepine. Patients who do not respond to drugs may be helped by surgery on the trigeminal nerve.
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Sinus infection. In a condition called acute sinusitis, a viral or bacterial infection of the upper respiratory tract spreads to the membrane which lines the sinus cavities. When one or more of these cavities are filled with fluid from the inflammation, they become painful. Treatment of acute sinusitis includes antibiotics, analgesics, and decongestants. Chronic sinusitis may be caused by an allergy to such irritants as dust, ragweed, animal hair, and smoke. Research scientists disagree about whether chronic sinusitis triggers headache.

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What Causes Headache in Children?

Like adults, children experience the infections, trauma, and stresses that can lead to headaches. In fact, research shows that as young people enter adolescence and encounter the stresses of puberty and secondary school, the frequency of headache increases.

Migraine headaches often begin in childhood or adolescence. According to recent surveys, as many as half of all schoolchildren experience some type of headache.

Children with migraine often have nausea and excessive vomiting. Some children have periodic vomiting, but no headache - the so-called abdominal migraine. Research scientists have found that these children usually develop headaches when they are older.

Physicians have many drugs to treat migraine in children. Different classes that may be tried include analgesics, antiemetics, anticonvulsants, beta-blockers, and sedatives. A diet may also be prescribed to protect the child from foods that trigger headache. Sometimes psychological counseling or even psychiatric treatment for the child and the parents is recommended

Childhood headache can be a sign of depression. Parents should alert the family pediatrician if a child develops headaches along with other symptoms such as a change in mood or sleep habits. Antidepressant medication and psychotherapy are effective treatments for childhood depression and related headache.
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Conclusion

If you suffer from headaches and none of the standard treatments help, do not despair. Some people find that their headaches disappear once they deal with a troubled marriage, pass their certifying board exams, or resolve some other stressful problem. Others find that if they control their psychological reaction to stress, the headaches disappear.

"I had migraines for several years," says one woman, "and then they went away. I think it was because I lowered my personal goals in life. Today, even though I have 100 things to do at night, I don't worry about it. I learned to say no."

For those who cannot say no, or who get headaches anyway, today's headache research offers hope. The work of NINDS-supported scientists around the world promises to improve our understanding of this complex disorder and provide better tools to treat it.

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Where can I get more information?

For more information on neurological disorders or research programs funded by the National Institute of Neurological Disorders and Stroke, contact the Institute's Brain Resources and Information Network (BRAIN) at:

BRAIN
P.O. Box 5801
Bethesda, MD 20824
(800) 352-9424
http://www.ninds.nih.gov

Information also is available from the following organizations:
American Council for Headache Education
19 Mantua Road
Mt. Royal, NJ 08061
achehq@talley.com
http://www.achenet.org
Tel: 856-423-0258 800-255-ACHE (255-2243)
Fax: 856-423-0082
Non-profit patient-health professional partnership dedicated to advancing the treatment and management of headache and to raising public awareness of headache as a valid, biologically-based illness.

National Headache Foundation
820 N. Orleans
Suite 217
Chicago, IL 60610-3132
info@headaches.org
http://www.headaches.org
Tel: 312-274-2650 888-NHF-5552 (643-5552)
Fax: 312-640-9049
Non-profit organization dedicated to service headache sufferers, their families, and the healthcare practitioners who treat them. Promotes research into headache causes and treatments and educates the public.

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Glossary

angiography-an imaging technique that provides a picture, called an angiogram, of blood vessels.

aura-a symptom of classic migraine headache in which the patient sees flashing lights or zigzag lines, or may temporarily lose vision

basilar artery migraine-migraine, occurring primarily in young women and often associated with the menstrual cycle, that involves a disturbance of a major brain artery. Symptoms include vertigo, double vision, and poor muscular coordination.

benign exertional headache-headache brought on by running, lifting, coughing, sneezing, or bending.

biofeedback-a technique in which patients are trained to gain some voluntary control over certain physiological conditions, such as blood pressure and muscle tension, to promote relaxation. Thermal biofeedback helps patients consciously raise hand temperature, which can sometimes reduce the number and intensity of migraines.

cluster headaches-intensely painful headaches-occurring suddenly and lasting between 30 and 45 minutes-named for their repeated occurrence in groups or clusters. They begin as minor pain around one eye and eventually spread to that side of the face.

computer tomography (CT)-an imaging technique that uses X-rays and computer analysis to provide a picture of body tissues and structures.

dihydroergotamine-a drug that is given by injection to treat cluster headaches. It is a form of the antimigraine drug ergotamine tartrate.

electroencephalogram (EEG)-a technique for recording electrical activity in the brain.

electromyography (EMG)-a special recording technique that detects electric activity in muscle. Patients are sometimes offered a type of biofeedback called EMG training, in which they learn to control muscle tension in the face, neck, and shoulders.

endorphins-naturally occurring painkilling chemicals. Some scientists theorize that people who suffer from severe headache have lower levels of endorphins than people who are generally pain free.

ergotamine tartrate-a drug that is used to control the painful dilation stage of migraine.

hemiplegic migraine-a type of migraine causing temporary paralysis on one side of the body (hemiplegia)

inflammatory headache-a headache that is a symptom of another disorder, such as sinus infection, and is treated by curing the underlying problem.

magnetic resonance imaging (MRI)-an imaging technique that uses radio waves, magnetic fields, and computer analysis to provide a picture of body tissues and structures.

migraine-a vascular headache believed to be caused by blood flow changes and certain chemical changes in the brain leading to a cascade of events - including constriction of arteries supplying blood to the brain and the release of certain brain chemicals - that result in severe head pain, stomach upset, and visual disturbances.

muscle-contraction headaches-headaches caused primarily by sustained muscle tension or, possibly, by restricted blood flow to the brain. Two forms of muscle-contraction headache are tension headache, induced by stress, and chronic muscle-contraction headache, which can last for extended periods, involves steady pain, and is usually felt on both sides of the head.

nociceptors-the endings of pain-sensitive nerves that, when stimulated by stress, muscular tension, dilated blood vessels, or other triggers, send messages up the nerve fibers to nerve cells in the brain, signaling that a part of the body hurts.

ophthalmoplegic migraine-a form of migraine felt around the eye and associated with a droopy eyelid, double vision, and other sight problems.

prostaglandins-naturally occurring pain-producing substances thought to be implicated in migraine attacks. Their release is triggered by the dilation of arteries. Prostaglandins are extremely potent chemicals involved in a diverse group of physiological processes.

serotonin-a key neurotransmitter that acts as a powerful constrictor of arteries, reducing the blood supply to the brain and contributing to the pain of headache.

sinusitis-an infection, either viral or bacterial, of the sinus cavities. The infection leads to inflammation of these cavities, causing pain and sometimes headache.

sumatriptan-a commonly used migraine drug that binds to receptors for the neurotransmitter serotonin.

status migrainosus-a rare, sustained, and severe type of migraine, characterized by intense pain and nausea and often leading to hospitalization of the patient.

thermography-a technique sometimes used for diagnosing headache in which an infrared camera converts skin temperature into a color picture, called a thermogram, with different degrees of heat appearing as different colors.

temporomandibular joint dysfunction-a disorder of the joint between the temporal bone (above the ear) and the lower jaw bone that can cause muscle-contraction headaches.

tic douloureux-see trigeminal neuralgia

traction headaches-headaches caused by pulling or stretching pain-sensitive parts of the head, as, for example, when eye muscles are tensed to compensate for eyestrain.

trigeminal neuralgia-a condition resulting from a disorder of the trigeminal nerve. Symptoms are headache and intense facial pain that comes in short, excruciating jabs.

vascular headaches- headaches caused by abnormal function of the brain's blood vessels or vascular system. Migraine is a type of vascular headache

Physical Diagnostic (Series 1 : Emergency)

2007-12-09T12:25:00.001-08:00

"Emergency medicine is a medical specialty -- a field of practice based on the knowledge and skills required for the prevention, diagnosis and management of acute and urgent aspects of illness and injury affecting patients of all age groups with a full spectrum of undifferentiated physical and behavioral disorders. It further encompasses an understanding of the development of pre-hospital and in-hospital emergency medical systems and the skills necessary for this development."

International Federation for Emergency Medicine 1991 (wikipedia)

Hypertension

2007-12-09T12:24:00.004-08:00

Hypertension is defined as the presence of a blood pressure (BP) elevation to a level that places patients at increased risk for target organ damage in several vascular beds, including the retina, brain, heart, kidneys, and large conduit arteries.

Etiology Of all hypertensive patients, 90% have essential hypertension; the remainder
have hypertension secondary to causes such as renal parenchymal disease, renovascular disease, pheochromocytoma, Cushing syndrome, primary hyperaldosteronism, coarctation of the aorta, and uncommon autosomal-dominant or -recessive diseases of the adrenalâ€“renal axis that result in salt retention.
Blood pressure readings are measured in millimeters of mercury (mmHg) and usually given as 2 numbers. For example, 140 over 90 (written as 140/90).
* The top number is your systolic pressure, the pressure created when your heart beats. It is considered high if it is consistently over 140.
* The bottom number is your diastolic pressure, the pressure inside blood vessels when the heart is at rest. It is considered high if it is consistently over 90.
Patient education is an essential component of the treatment plan and promotes patient compliance. Physicians should emphasize that:
Lifelong treatment usually is required.
Symptoms are an unreliable gauge of severity of hypertension.
Prognosis improves with proper management.

Physical Diagnostic (Series 1 : Neurology Exam)

2007-12-09T12:24:00.003-08:00

Let See how the initial patient encounter and greeting provides important information for the neurological evaluation. In this medical movie/video will explain about Orientation, Cranial Nerves, Power/Sensory/Gait

Physcal Diagnostic (Series 1 : Pulmunary Exam)

2007-12-09T12:24:00.001-08:00

Medical Video examination of pulmonary

Physical Diagnostic (Series 1 : Cardiology Exam)

2007-12-09T12:23:00.005-08:00

Medical Video Physical exam of Cardiology System

Physical Diagnostic Series 1 (Abdominal Exam)

2007-12-09T12:23:00.003-08:00

This Medical Movie will so You about examination about abdominal

Pysical Diagnostic Series (HEENT)

2007-12-09T12:23:00.001-08:00

In this section of Physical Diagnositic video will telll about Head, Eye, Ear, Nose and Throat Examination (HEENT).
i hope u enjoy this medical movie guide. thanks

Amniocentesis

2007-12-09T12:22:00.003-08:00

Amniocentesis is a diagnostic procedure performed by inserting a hollow needle through the abdominal wall into the uterus and withdrawing a small amount of fluid from the sac surrounding the fetus.
Now U can view this animation of Amniocentesis ......

Physical Diagnostic Series 1 (Integrative)

2007-12-09T12:22:00.001-08:00

this is the last one of series 1 Physical Exam movie. hope this medical movie can help u to learning physical diagnositic.
see u in the next episode of physical examination movie

Physical Examination (Abodminal Exam Part 1)

2007-12-09T12:21:00.002-08:00

I'm soryy for late update my blog, this is because i have trouble with my internet.
now i will upload another version of physcical diagnostic/examination hope u enjoy and keep visit my blog, don't forget to feedback if u dont mind.
Thank for visit my blog

Abodominal Exam (part 1)

Abdomina Exam (part 2)

To be continue ....

Physical Examination (Abodminal Exam Part 2)

2007-12-09T12:21:00.001-08:00

Now in this medical movie series will Learn about auscultation anda percusion of abdominal...

Abdominal Examination part 3

Abdominal Examination part 4

to be continued ....
Hope u Like it, see You

Physical Examination (Abodminal Exam Part 3)

2007-12-09T12:20:00.001-08:00

learn more form this medical movie how to palpation abdomen include hepar

Abdominal Examination Part 5
Palpation of abdomen

Abdominal Examination Part 6
this medical movie will see u how to Palpation of hepar

To be continue...

Physical Examination (Abdominal end)

2007-12-09T12:19:00.002-08:00

Abdominal Exam Part 7

Abdominal Exam Part 8

Summary

Parasternal Blocks

2007-12-09T12:19:00.001-08:00

It has been the key step in my consistent use of on-table extubation and the movie shows how perform the parasternal blocks. There are 4 main points:1) A large needle (18 guage) 2) 50:50 mixture of plain bupivicaine 0.25% and lidocaine 1%. No epinephrine is used 3) Infusion into the chest tube tracts, and 4) Infusion into each interspace along (http://www.hsforum.com/stories/storyReader$3700)

Atelectasis

2007-12-09T11:44:00.001-08:00

Atelectasis is the collapse of part or all of a lung. It is caused by a blockage of the air passages (bronchus or bronchioles) or by pressure on the lung.

Symptoms

* cough, but not prominent
* chest pain (rare)
* breathing difficulty
* low oxygen saturation
* fever--debatable; no evidence to support this, although it is widely accepted
* pleural effusion (transudate type)
* cyanosis (late sign)
* increased heart rate

Allergic Rhinitis

2007-12-09T11:43:00.002-08:00

Allergic rhinitis is an inflammation of the nasal passages, usually associated with watery nasal discharge and itching of the nose and eyes.
Allergic rhinitis is a collection of symptoms, predominantly in the nose and eyes, caused by airborne particles of dust, dander, or plant pollens in people who are allergic to these substances.

Myocardia Infraction

2007-12-09T11:43:00.001-08:00

Physical Examination of Neck Vessels and Heart

2007-12-09T11:42:00.001-08:00

See U again, in physical examination series now U will learn about Physical Exam of Neck Vessels and Heart
lets started

Introduction

Examination of the Neck Vessels

Physical Examination (Examination of the Heart)

2007-12-09T11:41:00.001-08:00

The major elements of the cardiac exam include observation, palpation and, most importantly, auscultation (percussion is omitted). As with all other areas of the physical exam, establishing adequate exposure and a quiet environment are critical

Physical Examination (Review of Heart Sounds)

2007-12-09T11:40:00.001-08:00

Ten heart sounds to listen to including a normal heart to compare sounds.

Review of Heart Sounds

Physical Examination (Auscultation of the Heart)

2007-12-09T11:39:00.002-08:00

Auscultation is that part of the physical examination involving the act of listening with a stethoscope to sounds made by the heart, lungs, and blood.

Physical Examination (Heart Sounds: S1, S2)

2007-12-09T11:39:00.001-08:00

Normal heart sounds are called S1 and S2. They are the "lubb-dupp" sounds that are thought of as the heartbeat. These sounds are produced when the heart valves close.

Physical Examination (Heart Sounds: S3, S4, murmurs)

2007-12-09T11:26:00.000-08:00

Third Heart Sound S3 : Low frequency sound in early diastole, 120 to 180 ms after S2
Fourth Heart Sound S4 : Low frequency sound in presystolic portion of diastole