by Ewen Callaway Even at the tender age of 3, children who will go on to be convicted of a crime are less likely to learn to link fear with a certain noise than those who don't. This may mean that an insensitivity to fear could be a driving force behind criminal behaviour. Adult criminals tend to be fearless, but whether this characteristic emerges before or after they commit a crime wasn't clear, says Adrian Raine, a psychologist at the University of Pennsylvania in Philadelphia. To find out, Raine and colleague Yu Gao turned to data from a 1970s study, collected as part of a decades-long project to understand the biological and environmental factors underlying mental illness. Back then, researchers led by Raine's former research supervisor had measured the sweat response of about 1800 3-year-olds in Mauritius when they were exposed to two different sounds. One sound was always followed by a noisy blare, the other by nothing. The children learned to anticipate which sound preceded the blare, and sweated in response to it – an indicator of fear. Decades later, Raine's own team looked to see if any of the subjects had criminal records and found 137 that did. The team discovered that, as toddlers, these people had sweated significantly less in anticipation of the blare compared with subjects of similar race, gender and background for whom no criminal record was found. © Copyright Reed Business Information Ltd

Keyword: Emotions; Aggression
Link ID: 13481 - Posted: 06.24.2010

by Carl Zimmer Numbers make modern life possible. “In a world without numbers,” University of Rochester neuroscientist Jessica Cantlon and her colleagues recently observed in the journal Trends in Cognitive Sciences, “we would be unable to build a skyscraper, hold a national election, plan a wedding, or pay for a chicken at the market.” The central role of numbers in our world testifies to the brain’s uncanny ability to recognize and understand them—and Cantlon is among the researchers trying to find out exactly how that skill works. Traditionally, scientists have thought that we learn to use numbers the same way we learn how to drive a car or to text with two thumbs. In this view, numbers are a kind of technology, a man-made invention to which our all-purpose brains can adapt. History provides some support. The oldest evidence of people using numbers dates back about 30,000 years: bones and antlers scored with notches that are considered by archaeologists to be tallying marks. More sophisticated uses of numbers arose only much later, coincident with the rise of other simple technologies. The Mesopotamians developed basic arithmetic about 5,000 years ago. Zero made its debut in A.D. 876. Arab scholars laid the foundations of algebra in the ninth century; calculus did not emerge in full flower until the late 1600s. Despite the late appearance of higher mathematics, there is growing evidence that numbers are not really a recent invention—not even remotely. Cantlon and others are showing that our species seems to have an innate skill for math, a skill that may have been shared by our ancestors going back least 30 million years.

Keyword: Miscellaneous
Link ID: 13480 - Posted: 06.24.2010

Frequent use of ketamine - a drug popular with clubbers - is being linked with memory problems, researchers say. The University College London team carried out a range of memory and psychological tests on 120 people. They found frequent users performed poorly on skills such as recalling names, conversations and patterns. Previous studies said the drug might cause kidney and bladder damage. The London team and charity Drugscope said users should be aware of the risks. Ketamine - or Special K as it has been dubbed - acts as a stimulant and induces hallucinations. It has been increasing in popularity, particularly as an alternative to ecstasy among clubbers, as the price has fallen over recent years. A gram now costs about £20 - half the price of cocaine. In response, the drug was made illegal three years ago - it is currently graded class C - although it still remains legal for use as an anaesthetic and a horse tranquiliser. The study split the participants into five groups - those using the drug each day, recreational users who took the drug once or twice a month, former users, those who used other drugs and people who did not take any drugs. All of the people took part in a series of memory tests as well as completing questionnaires and were then followed up a year later, the Addiction journal reported. Researchers found the frequent users group performed significantly worse on the memory tests - in some they made twice as many errors. The study also showed performance worsened over the course of the year. There was no significant difference between the other groups. However, all groups of ketamine users showed evidence of unusual beliefs or mild delusions, such as conspiracy theories, the psychological questionnaires showed. (C)BBC

Keyword: Drug Abuse; Learning & Memory
Link ID: 13479 - Posted: 11.17.2009

By Christof Koch Surely there must have been times in high school or college when you laid in bed, late at night, and wondered where your “free will” came from? What part of the brain—if it is the brain—is responsible for deciding to act one way or another? One traditional answer is that this is not the job of the brain at all but rather of the soul. Hovering above the brain like Casper the Friendly Ghost, the soul freely perturbs the networks of the brain, thereby triggering the neural activity that will ultimately lead to behavior. Although such dualistic accounts are emotionally reassuring and intuitively satisfying, they break down as soon as one digs a bit deeper. How can this ghost, made out of some kind of metaphysical ectoplasm, influence brain matter without being detected? What sort of laws does Casper follow? Science has abandoned strong dualistic explanations in favor of natural accounts that assign causes and responsibility to specific actors and mechanisms that can be further studied. And so it is with the notion of the will. Over the past decade psychologists such as Daniel M. Wegner of Harvard University amassed experimental evidence for a number of conscious sensations that accompany any willful action. The two most important are intention and agency. Prior to voluntary behavior lies a conscious intention. When you decide to lift your hand, this intention is followed by planning of the detailed movement and its execution. Subjectively, you experience a sensation of agency. You feel that you, not the person next to you, initiated this action and saw it through. If a friend were to take your hand and pull it above your head, you would feel your arm being dragged up, but you would not feel any sense of being responsible for it. The important insight here is that the consciously experienced feelings of intention and agency are no different, in principle, from any other consciously experienced sensations, such as the briny taste of chicken soup or the red color of a Ferrari. © 1996-2009 Scientific American Inc

Keyword: Attention
Link ID: 13478 - Posted: 06.24.2010

By Michael Torrice Some people can read your face and know you've had a bad day. Others seem oblivious. Now, researchers have pinpointed a genetic explanation for why some people are better empathizers than others. Empathy is crucial for our everyday social interactions. Neuroscientists have focused on a possible role for oxytocin, a hormone that seems to help us get along. Human volunteers trust others more to dole out money fairly when under the influence of the hormone, for example. And recently, scientists have linked a variation, or polymorphism, in the gene that codes for the oxytocin receptor to autism, a disorder defined by impaired social interactions. Neuropsychologist Sarina Rodrigues of Oregon State University in Corvallis and colleagues decided to look for a connection between this polymorphism, called rs53576, and empathy differences in the general population. To measure empathy in 192 college students, the researchers used a standard evaluation called the Reading the Mind in the Eyes Test. Each subject looks at images of a movie still cropped to show only the actor's eyes. For each image, the researchers display four words, such as "playful" or "comforting," and ask the students to pick the word that best matches what the person is thinking or feeling. Autistic patients score poorly on this test, and past studies have shown that people who receive a snort of oxytocin perform better than those who receive a placebo. © 2009 American Association for the Advancement of Science

Keyword: Emotions; Autism
Link ID: 13477 - Posted: 06.24.2010

By DENISE GRADY Dr. Howard Riina threaded a slender tube through a maze of arteries in Dennis Sugrue’s brain, watching X-ray images on a monitor to track his progress. At the site where a previous operation had removed a malignant tumor, he infused a drug called mannitol and unleashed a flood of the cancer drug Avastin. Doctors and nurses watched intently, worried that the Avastin could cause brain swelling, a hemorrhage or a seizure. But Mr. Sugrue emerged unscathed. A half hour after the procedure, he woke up from anesthesia mumbling, “More is better,” and wishing aloud that he could have had a bigger dose. It was an experiment. Mr. Sugrue, 50, who works for a hedge fund and has two teenage children, was in a study for people with glioblastoma — the same type of brain tumor that killed Senator Edward M. Kennedy of Massachusetts in August — and was only the second person ever to have Avastin sprayed directly into his brain. Getting drugs into the brain has always been a major challenge in treating tumors and other neurological diseases, because the blood-brain barrier, a natural defense system, keeps many drugs out. The study that Mr. Sugrue is in, at NewYork-Presbyterian/Weill Cornell, combines old technologies in a new way to open the barrier and deliver extraordinarily high doses of Avastin straight to these deadly tumors — without soaking the rest of the brain in the drug and exposing it to side effects. Copyright 2009 The New York Times Company

Keyword: Miscellaneous
Link ID: 13476 - Posted: 06.24.2010

By Emily Sohn Insects may have tiny brains, but they can perform some seriously impressive feats of mental gymnastics. According to a growing number of studies, some insects can count, categorize objects, even recognize human faces -- all with brains the size of pinheads. Despite many attempts to link the volume of an animal's brain with the depth of its intelligence, scientists now propose that it's the complexity of connections between brain cells that matters most. Studying those connections -- a more manageable task in a little brain than in a big one -- could help researchers understand how bigger brains, including those of humans, work. Figuring out how a relatively small number of cells work together to process complex concepts could also lead to "smarter" computers that do some of the same tasks. "The question is: If these insects can do these things with such little brains, what does anything need a big brain for?" said Lars Chittka, who presented his arguments along with colleague Jeremy Niven in the journal Current Biology. "Bigger isn't necessarily better, and in some cases it could be quite the opposite." Because we are intelligent animals with big brains, people have long assumed that big brains are smarter brains. Yet, scientists have found scant evidence to support that view, Chittka said. Studies that have made those connections are fraught with problems. "If you try many measurements," he said, "Eventually you will find one that shows a correlation." © 2009 Discovery Communications, LLC

Keyword: Intelligence; Evolution
Link ID: 13475 - Posted: 06.24.2010

By Rita Rubin, USA TODAY Steve Ballou, an ex-smoker for more than a decade, started slipping back into his old ways with cigars. He'd have one when he was out with the guys, then when he was driving home from work, then one after dinner. This went on for several years, but he thought of himself as a cigar aficionado, not a relapsed smoker, since cigarettes were never on the menu. Until he vacationed in the City of Lights. Ballou will forever associate Paris' nickname with the act of lighting a cigarette. Over lunch one day, he realized he'd forgotten to buy a cigar to savor after the meal. So he bummed a cigarette from his wife, an occasional smoker. "I smoked half her pack that afternoon, and from that point on, I was a smoker," says Ballou, 54, a Sherborn, Mass., resident who works in financial services. He had a smoker's typical love/hate relationship with cigarettes. "I really did want to quit, but I was a nicotine addict. I needed something to help me get over this." That something was a nicotine vaccine. Researchers are investigating whether the same approach used to prevent infectious diseases could treat addictions to such drugs as nicotine and cocaine. None is yet on the market, but in late September, the National Institute on Drug Abuse (NIDA) released a $10 million stimulus grant to Nabi Pharmaceuticals to help pay for the first Phase III trial – a large study designed to confirm effectiveness and monitor side effects – of a smoking-cessation vaccine. Company spokesman Greg Fries says Nabi, based in Rockville, Md., expects to begin enrolling patients in the NicVax study by year's end. Copyright 2009 USA TODAY,

Keyword: Drug Abuse
Link ID: 13474 - Posted: 06.24.2010

Hypnosis has a "very real" effect that can be picked up on brain scans, say Hull University researchers. An imaging study of hypnotised participants showed decreased activity in the parts of the brain linked with daydreaming or letting the mind wander. The same brain patterns were absent in people who had the tests but who were not susceptible to being hypnotised. One psychologist said the study backed the theory that hypnosis "primes" the brain to be open to suggestion. Hypnosis is increasingly being used to help people stop smoking or lose weight and advisers recently recommended its use on the NHS to treat irritable bowel syndrome. It is not the first time researchers have tried to use imaging studies to monitor brain activity in people under hypnosis. But the Hull team said these had been done while people had been asked to carry out tasks, so it was not clear whether the changes in the brain were due to the act of doing the task or an effect of hypnosis. In the latest study, the team first tested how people responded to hypnosis and selected 10 individuals who were "highly suggestible" and seven people who did not really respond to the technique other than becoming more relaxed. The participants were asked to do a task under hypnosis, such as listening to non-existent music, but unknown to them the brain activity was being monitored in the rest periods in between tasks, the team reported in the journal Consciousness and Cognition. In the "highly suggestible" group there was decreased activity in the part of the brain involved in daydreaming or letting the mind wander - also known as the "default mode" network. BBC © MMIX

Keyword: Attention; Brain imaging
Link ID: 13473 - Posted: 06.24.2010

Chemicals in plastics alter the brains of baby boys making them "more feminine", say US researchers. Males exposed to high doses in the womb went on to be less likely to play with boys' toys like cars or to join in rough and tumble games, they found. The University of Rochester team's latest work adds to concerns about the safety of phthalates, found in vinyl flooring and PVC shower curtains. The findings are reported in the International Journal of Andrology. Phthalates have the ability to disrupt hormones, and have been banned in toys in the EU for some years. However, they are still widely used in many different household items, including plastic furniture and packaging. There are many different types and some mimic the female hormone oestrogen. The same researchers have already shown that this can mean boys are born with genital abnormalities. Now they say certain phthalates also impact on the developing brain, by knocking out the action of the male hormone testosterone. Dr Shanna Swan and her team tested urine samples from mothers over midway through pregnancy for traces of phthalates. The women, who gave birth to 74 boys and 71 girls, were followed up when their children were aged four to seven and asked about the toys the youngsters played with and the games they enjoyed. They found that two phthalates DEHP and DBP can affect play behaviour. BBC © MMIX

Keyword: Sexual Behavior; Neurotoxins
Link ID: 13472 - Posted: 06.24.2010

Lizzie Buchen A once-mysterious neural pathway may have a crucial role in making injured areas overly sensitive to touch, a study in mice suggests. When a person has any kind of injury — a broken shin, for example, or a sunburn — the pain system becomes hypersensitized, firing up in response to normally painless sensations induced by, for instance, walking or a gentle massage. Normally, this tenderness protects the vulnerable tissue as it heals. But occasionally the pain can overstay its usefulness, becoming chronic in conditions such as arthritis. Now, neuroscientists Robert Edwards and Allan Basbaum from the University of California, San Francisco, and their colleagues have found that a small subset of nerve fibres, the function of which remained a puzzle since their discovery decades ago1, could be routing innocuous touch sensations to the pain pathway when there's an injury. "Surprise would be an understatement," says Basbaum, referring to the findings. "No one knew anything about what these fibres were doing." The team's findings are published by Nature2. The researchers found that the fibres, called unmyelinated low-threshold mechanoreceptors (C-LTMRs), are easily stimulated, unlike classic pain fibres, which respond only when the sensation is intense. But C-LTMRs aren't usually used to detect light touch — this falls to another another major group of sensory neurons — so their role was unclear. The small population of cells have remained enigmatic because they have been difficult to target specifically. © 2009 Nature Publishing Group

Keyword: Pain & Touch
Link ID: 13471 - Posted: 06.24.2010

HONG KONG - People of Japanese and European descent who have mutant versions of five genes may be at higher risk of developing Parkinson's disease, two large teams of researchers have found. The two independent studies, published in the latest issue of Nature Genetics, involved more than 25,000 participants in total and are the largest studies to date to try to uncover genetic associations behind Parkinson's disease. A study in Japan looked only at ethnic Japanese while a second study, in the United States, focused only on people of European heritage. In the first study, Tatsushi Toda of Japan's Kobe University and colleagues sequenced the genes of 2,011 participants with the disease and 18,381 others without the disease. They found that those with the disease had variants of the genes PARK16, BST1, SNCA and LRRK2. In the second study, researchers led by Andrew Singleton at the National Institutes of Health's (NIH) laboratory of neurogenetics in the United States analyzed the genes of more than 5,000 patients of European ancestry who suffer from the disease and detected strong links between Parkinson's and variants of the genes SNCA and MAPT. The two teams later compared their data and found that variants of PARK16, SNCA and LRRK2 carry risk of Parkinson's in both Japanese and European populations, while variants of BST1 and MAPT were population-specific. Copyright 2009 Reuters.

Keyword: Parkinsons; Genes & Behavior
Link ID: 13470 - Posted: 06.24.2010

By Bruce Bower Unlike most Western guys and gals looking for love, Africa’s Hadza foragers pair up without regard to each other’s size and strength, a new study finds. And that stature-may-care approach underscores the often unappreciated variety of human mating strategies, the researchers say. Hadza marriages don’t tend to consist of individuals with similar heights, weights, body mass indexes, body-fat percentages or grip strengths, say behavioral ecologist Rebecca Sear of the London School of Economics and anthropologist Frank Marlowe of Florida State University in Tallahassee. Neither do Hadza couples feature a disproportionate percentage of husbands taller than their wives, as has been documented in some Western nations, the researchers report in the Oct. 23 Biology Letters. Almost no Hadza individuals mention height or size when asked to explain what makes for an attractive mate, Sear and Marlowe add. People everywhere seek healthy, fertile marriage partners, Sear proposes. “But I suspect there may not be a preference for one particular signal of health in mates across every population,” she says. Among the roughly 1,000 Hadza scraping out a living in rural Tanzania, knowledge of a potential mate’s health history may render that person’s height and weight irrelevant, the researchers suggest. Also, any health benefits of being big may get nullified by the difficulty of maintaining a large body during periodic food shortages endured by the Hadza. © Society for Science & the Public 2000 - 2009

Keyword: Sexual Behavior; Evolution
Link ID: 13469 - Posted: 06.24.2010

By Kay Lazar The word teasers flashing on his computer screen seemed tuned to his personal abilities. And the accompanying voice track prodded or consoled - “it actually congratulates you,’’ he said - based on his answers. Now, the 92-year-old former management executive, an engineer by training and crossword puzzler by hobby, is scheduling computer time for fellow residents at the Fox Hill Village retirement community in Westwood. The facility just purchased a couple of these newfangled brain games and residents are lining up for 20-minute sessions. The products are spreading like kudzu through retirement communities and senior centers, as older Americans search for ways to stay mentally sharp. Researchers, however, have yet to determine whether these brain games, targeted to seniors and now an $80 million-a-year market, deliver what they promise. “The jury is still very much out,’’ said Peter Snyder, a brain researcher at Brown University’s Alpert Medical School, who analyzed 10 studies on the issue and came away unimpressed by the quality and quantity of research. In an article published earlier this year in the journal Alzheimer’s & Dementia, Snyder concluded there was no evidence the products, typically computer software costing several hundred to a couple of thousand dollars, stave off dementia in healthy elders. Snyder did not delve into the effect of brain exercises on adults who already have cognitive impairments. © 2009 NY Times Co

Keyword: Learning & Memory; Alzheimers
Link ID: 13468 - Posted: 06.24.2010

By Nick Triggle Needless use of anti-psychotic drugs is widespread in dementia care and contributes to the death of many patients, an official review suggests. About 180,000 patients a year are given the drugs in care homes, hospitals and their own homes to manage aggression. But the expert review - commissioned by ministers - said the treatment was unnecessary in nearly 150,000 cases and was linked to 1,800 deaths. The government in England has agreed to take steps to reduce use of the drugs. The review - and the government pledge to take action - comes after long-running concerns about the use of anti-psychotic drugs. Over the past 30 years, the NHS has increasingly turned to the treatment, which was originally aimed at people with schizophrenia, as it has struggled to cope with the rise in people with dementia. There are currently 700,000 people in the UK with the condition, but this is expected to rise to one million in the next 10 years because of the ageing population. The review, led by King's College London expert Professor Sube Banerjee, accepted that for some people anti-psychotic drugs would be necessary. But it said they should be used only for a maximum of three months and when the person represented a risk to themselves or others. Professor Banerjee estimated that of the 180,000 people given the drugs each year, only 36,000 benefited. He said health and social care services needed to develop a "different mindset". (C)BBC

Keyword: Alzheimers; Schizophrenia
Link ID: 13467 - Posted: 11.14.2009

Patients complaining of grinding their teeth in their sleep are being given mild electric shock treatment. A chain of private dental practices in Hull is trialling a device which delivers a tiny electrical impulse when it detects grinding is about to begin. Teeth grinding - or bruxism - is a common and usually harmless habit induced by stress. It can, however, cause headaches and stiff necks, as well as irritating a sleeping partner. Traditional treatments involve wearing a plastic device at night which prevents the top and bottom teeth from meeting. With this new device, Grindcare , developed in Denmark, a small electrode is placed on the temple which then monitors the movement of facial muscles. When it detects tension mounting, it delivers a tiny electrical impulse - or biofeedback. This is not consciously detected by the sleeping patient but still serves to relax the muscles. The device is said to reduce grinding by as much as 80% within two months. Other ways of tackling bruxism include counselling and relaxation therapies to resolve the initial source of stress and tension. But Dr David Vivian, the dentist trialling the device, said that grinding could worsen existing anxieties. "The broken sleep pattern caused by grinding can exacerbate any stresses or worries already being felt by the patient, and add an extra layer of anxiety to their lives. They may also be resorting to over-the-counter painkillers to treat side effects, such as headaches, and finding that they are having to increase the dosage all the time. (C)BBC

Keyword: Sleep
Link ID: 13466 - Posted: 11.14.2009

By RONI CARYN RABIN There are probably better ways to start the day, but a new study suggests that early morning is an ideal time to schedule a colonoscopy. Physicians detected 20 percent more polyps during the first procedures of the day than they did during procedures performed later in the morning and the early afternoon, the study found. “Hour by hour, there were fewer polyps found as the day progressed,” said Dr. Brennan M. R. Spiegel, an assistant professor of medicine at U.C.L.A. and an author of the study, which appears in the November issue of the journal Clinical Gastroenterology and Hepatology. “It’s a small effect, very small, but very measurable and definitely there.” A study done at the Cleveland Clinic and published this year found similar results, noting that 29.3 percent of morning procedures resulted in detection of at least one polyp, compared with 25.3 percent of the afternoon procedures. The new study looked at the results from colonoscopies performed on 477 patients at the West Los Angeles Veterans Medical Center in 2006 and 2007. Most of the procedures were performed by a physician training in gastroenterology who was supervised by a faculty member. Procedures were performed between 7:45 a.m. and 1 p.m., and though they were done only in the early hours of the day, the analysis found that 20 percent more polyps were detected during the earliest colonoscopies. The researchers tried to control for other factors that might have affected the results, including the fact that patients usually came in with better bowel preparation for morning procedures. Copyright 2009 The New York Times Company

Keyword: Biological Rhythms; Attention
Link ID: 13465 - Posted: 06.24.2010

By Charles Q. Choi Evolution in humans is commonly thought to have essentially stopped in recent times. But there are plenty of examples that the human race is still evolving, including our brains, and there are even signs that our evolution may be accelerating. Comprehensive scans of the human genome reveal that hundreds of our genes show evidence of changes during the past 10,000 years of human evolution. "We know the brain has been evolving in human populations quite recently," said paleoanthropologist John Hawks at the University of Wisconsin at Madison. Surprisingly, based on skull measurements, the human brain appears to have been shrinking over the last 5,000 or so years. "When it comes to recent evolutionary changes, we currently maybe have the least specific details with regard the brain, but we do know from archaeological data that pretty much everywhere we can measure — Europe, China, South Africa, Australia — that brains have shrunk about 150 cubic centimeters, off a mean of about 1,350. That's roughly 10 percent," Hawks said. "As to why is it shrinking, perhaps in big societies, as opposed to hunter-gatherer lifestyles, we can rely on other people for more things, can specialize our behavior to a greater extent, and maybe not need our brains as much," he added. © 2009 LiveScience.com.

Keyword: Evolution
Link ID: 13464 - Posted: 06.24.2010

By Bruce Bower For chimpanzees living in a forest surrounding the village of Bossou in Guinea, cracking nuts is a serious task with important steps. They are: First, lug large rocks to a spot near a nut-bearing tree, such as an oil palm. Next, gather the nuts and place them on the rocks. Then, obtain a smaller, graspable rock. Finally, smash the armored treats and let the shells fly. As clutches of apes pound away with devastating precision, these nut bashers create an unholy din akin to a human rock band. In fact, these West African chimps rock out in a surprising way. In this corner of the jungle, chimps appear to think more carefully about implements and how to assemble them than many scientists had assumed. A team led by anthropologist Susana Carvalho set up a nut-cracking lab in the forest near Bossou by placing seven piles of nuts and several dozen stones of various sizes, shapes and types inside a clearing. Over five field seasons, 14 of 17 chimps that regularly visited the clearing consistently reused the same pairs of stones, the scientists report in a special October issue of Animal Cognition. Most chimps, Carvalho says, used the stones together as one tool, a nutcracker. Carvalho suspects that watching the Bossou chimps at work will provide clues to the origins of the Stone Age, the 2.6 million years during which members of the human evolutionary family are known to have used and made stone tools of increasing complexity. She is one researcher participating in a scientific movement to merge strains of archaeology, anthropology, primatology and psychology into a hybrid field dubbed primate archaeology: the study of current and past material culture among apes and perhaps other nonhuman animals. © Society for Science & the Public 2000 - 2009

Keyword: Evolution; Intelligence
Link ID: 13463 - Posted: 06.24.2010

By RONI CARYN RABIN Many strokes cannot be explained by known risk factors like high blood pressure and smoking, and scientists have speculated that infection could play a role. Now a new study is linking cumulative exposure to five common pathogens with an increased risk for stroke. The infections in order of significance are Chlamydia pneumoniae, Helicobacter pylori, cytomegalovirus and herpes simplex viruses 1 and 2, according to the study, published online on Nov. 9 in The Archives of Neurology. The report will appear in the print edition of the journal in January. “Each of these common pathogens may persist after an acute infection and contribute to perpetuating a state of chronic low-level infection,” said the paper’s lead author, Dr. Mitchell S. V. Elkind, an associate professor of neurology at Columbia University Medical Center. Dr. Elkind said the low-level infection and inflammation in the vessel walls might be leading to disease. The researchers followed an ethnically diverse group of 1,625 residents from northern Manhattan whose average age was 68 and who had been stroke-free at the beginning of the study. After almost 8 years, 67 of the participants had suffered strokes. Copyright 2009 The New York Times Company

Keyword: Stroke; Neuroimmunology
Link ID: 13462 - Posted: 06.24.2010