A simple eye test may offer a fast and easy way to monitor patients with multiple sclerosis (MS), medical experts say in the journal Neurology. Optical Coherence Tomography (OCT) is a scan that measures the thickness of the lining at the back of the eye - the retina. It takes a few minutes per eye and can be performed in a doctor's surgery. In a trial involving 164 people with MS, those with thinning of their retina had earlier and more active MS. The team of researchers from the Johns Hopkins University School of Medicine say larger trials with a long follow up are needed to judge how useful the test might be in everyday practice. The latest study tracked the patients' disease progression over a two-year period. Unpredictable disease Multiple sclerosis is an illness that affects the nerves in the brain and spinal cord causing problems with muscle movement, balance and vision. In MS, the protective sheath or layer around nerves, called myelin, comes under attack which, in turn, leaves the nerves open to damage. There are different types of MS - most people with the condition have the relapsing remitting type where the symptoms come and go over days, weeks or months. Usually after a decade or so, half of patients with this type of MS will develop secondary progressive disease where the symptoms get gradually worse and there are no or very few periods of remission. BBC © 2012

Keyword: Multiple Sclerosis; Vision
Link ID: 17639 - Posted: 12.27.2012

Scientists say they have found a way to distinguish between different types of dementia without the need for invasive tests, like a lumbar puncture. US experts could accurately identify Alzheimer's disease and another type of dementia from structural brain patterns on medical scans, Neurology reports. Currently, doctors can struggle to diagnose dementia, meaning the most appropriate treatment may be delayed. More invasive tests can help, but are unpleasant for the patient. Despite being two distinct diseases, Alzheimer's and frontotemporal dementia, share similar clinical features and symptoms and can be hard to tell apart without medical tests. Both cause the person to be confused and forgetful and can affect their personality, emotions and behaviour. Alzheimer's tends to attack the cerebral cortex - the layer of grey matter covering the brain - where as frontotemporal dementia, as the name suggests, tends to affect the temporal and frontal lobes of the brain, which can show up on brain scans, but these are not always diagnostic. A lumbar puncture - a needle in the spine - may also be used to check protein levels in the brain, which tend to be higher in Alzheimer's than with frontotemporal dementia. BBC © 2012

Keyword: Alzheimers; Brain imaging
Link ID: 17638 - Posted: 12.27.2012

By DAVID DOBBS Psychological trauma dims tens of millions of lives around the world and helps create costs of at least $42 billion a year in the United States alone. But what is trauma, exactly? Both culturally and medically, we have long seen it as arising from a single, identifiable disruption. You witness a shattering event, or fall victim to it — and as the poet Walter de la Mare put it, “the human brain works slowly: first the blow, hours afterward the bruise.” The world returns more or less to normal, but you do not. In 1980, the Diagnostic and Statistical Manual of Mental Disorders defined trauma as “a recognizable stressor that would evoke significant symptoms of distress in almost everyone” — universally toxic, like a poison. But it turns out that most trauma victims — even survivors of combat, torture or concentration camps — rebound to live full, normal lives. That has given rise to a more nuanced view of trauma — less a poison than an infectious agent, a challenge that most people overcome but that may defeat those weakened by past traumas, genetics or other factors. Now, a significant body of work suggests that even this view is too narrow — that the environment just after the event, particularly other people’s responses, may be just as crucial as the event itself. The idea was demonstrated vividly in two presentations this fall at the Interdisciplinary Conference on Culture, Mind and Brain at the University of California, Los Angeles. Each described reframing a classic model of traumatic experience — one in lab rats, the other in child soldiers. © 2012 The New York Times Company

Keyword: Stress; Learning & Memory
Link ID: 17637 - Posted: 12.27.2012

Becky Summers Monkeys might not be known for their generosity, but when they do seem to act selflessly, a specific area in their brains keeps track of these kindnesses. The discovery of this neuronal tally chart may help scientists to understand the neural mechanisms underlying normal social behaviour in primates and humans, and might even provide insight into disorders such as autism, in which social processing is disrupted. Steve Chang and his colleagues from Duke University in Durham, North Carolina, used electrodes to directly record neuronal activity in three areas of the brain prefrontal cortex that are known to be involved in social decision-making, while monkeys performed reward-related tasks. When given the option either to drink juice from a tube themselves or to give the juice away to a neighbour, the test monkeys would mostly keep the drink. But when the choice was between giving the juice to the neighbour or neither monkey receiving it, the choosing monkey would frequently opt to give the drink to the other monkey. The researchers found that in two out of the three brain areas being recorded, neurons fired in the presence or absence of the juice reward only. By contrast, the third area — known as the anterior cingulate gyrus — responded only when the monkey allocated the juice to the neighbour and observed it being received. The authors suggest the neurons in the ACG respond to and record the act simultaneously. The study's results are published today in Nature Neuroscience1. © 2012 Nature Publishing Group,

Keyword: Emotions
Link ID: 17636 - Posted: 12.27.2012

By GRETCHEN REYNOLDS Anyone whose resolve to exercise in 2013 is a bit shaky might want to consider an emerging scientific view of human evolution. It suggests that we are clever today in part because a million years ago, we could outrun and outwalk most other mammals over long distances. Our brains were shaped and sharpened by movement, the idea goes, and we continue to require regular physical activity in order for our brains to function optimally. The role of physical endurance in shaping humankind has intrigued anthropologists and gripped the popular imagination for some time. In 2004, the evolutionary biologists Daniel E. Lieberman of Harvard and Dennis M. Bramble of the University of Utah published a seminal article in the journal Nature titled “Endurance Running and the Evolution of Homo,” in which they posited that our bipedal ancestors survived by becoming endurance athletes, able to bring down swifter prey through sheer doggedness, jogging and plodding along behind them until the animals dropped. Endurance produced meals, which provided energy for mating, which meant that adept early joggers passed along their genes. In this way, natural selection drove early humans to become even more athletic, Dr. Lieberman and other scientists have written, their bodies developing longer legs, shorter toes, less hair and complicated inner-ear mechanisms to maintain balance and stability during upright ambulation. Movement shaped the human body. But simultaneously, in a development that until recently many scientists viewed as unrelated, humans were becoming smarter. Their brains were increasing rapidly in size. Copyright 2012 The New York Times Company

Keyword: Evolution; Learning & Memory
Link ID: 17635 - Posted: 12.27.2012

By Rachel Ehrenberg Outfitted with a bionic eye, arm, legs and fantastic ’70s hair, Steve Austin was a cyborg whose implants allowed him to recover stolen atomic weapons, fight aliens and protect cryptographers in distress. Finally, real life is starting to catch up with the Six Million Dollar Man. In one of this year’s bionic breakthroughs, a paralyzed woman carried out her own superhuman feat: Using an implanted brain chip, she controlled a robotic arm with her mind (SN: 6/16/12, p. 5). She used the arm to grasp a cuppa joe and take a long, satisfying sip of coffee through a straw, an act she hadn’t done on her own for nearly 15 years. “We’re entering a really exciting area where we can develop all sorts of very complicated technologies that can actually have biomedical applications and improve the quality of life for people,” says bioengineer Grégoire Courtine of the Swiss Federal Institute of Technology in Lausanne. “It’s a revolution.” After her groundbreaking sip, Cathy Hutchinson, who had been paralyzed years earlier by a stroke, smiled and then laughed. A roomful of scientists burst into applause. This was a big year for prosthetic parts, both in and out of the lab. Athletes in London for the Paralympics and the Olympics sprinted on high-tech carbon blades and hurled javelins while balancing on the microprocessor-controlled C-Leg. People in wheelchairs used battery-powered robotic suits to keep their lower limbs in shape. A young man who lost his right leg in a motorcycle accident climbed the 103 flights of stairs in Chicago’s Willis Tower with a thought-controlled limb. That technology is still in development. But some bionic add-ons are starting to come out of the lab and into the clinic for the first time, though costs remain prohibitive for many potential users. © Society for Science & the Public 2000 - 2012

Keyword: Robotics
Link ID: 17634 - Posted: 12.27.2012

Cannabis makes pain more bearable rather than actually reducing it, a study from the University of Oxford suggests. Using brain imaging, researchers found that the psychoactive ingredient in cannabis reduced activity in a part of the brain linked to emotional aspects of pain. But the effect on the pain experienced varied greatly, they said. The researchers' findings are published in the journal Pain. The Oxford researchers recruited 12 healthy men to take part in their small study. Participants were given either a 15mg tablet of THC (delta-9-tetrahydrocannabinol) - the ingredient that is responsible for the high - or a placebo. The volunteers then had a cream rubbed into the skin of one leg to induce pain, which was either a dummy cream or a cream that contained chilli - which caused a burning and painful sensation. Each participant had four MRI scans which revealed how their brain activity changed when their perception of the pain reduced. Dr Michael Lee, lead study author from Oxford University's Centre for Functional Magnetic Resonance Imaging of the Brain, said: "We found that with THC, on average people didn't report any change in the burn, but the pain bothered them less." BBC © 2012

Keyword: Pain & Touch; Drug Abuse
Link ID: 17633 - Posted: 12.22.2012

by Karl Gruber Cigarettes leave you with more than a smoky scent on your clothes and fingernails. A new study has found strong evidence that tobacco use can chemically modify and affect the activity of genes known to increase the risk of developing cancer. The finding may give researchers a new tool to assess cancer risk among people who smoke. DNA isn't destiny. Chemical compounds that affect the functioning of genes can bind to our genetic material, turning certain genes on or off. These so-called epigenetic modifications can influence a variety of traits, such as obesity and sexual preference. Scientists have even identified specific epigenetic patterns on the genes of people who smoke. None of the modified genes has a direct link to cancer, however, making it unclear whether these chemical alterations increase the risk of developing the disease. In the new study, published in Human Molecular Genetics, researchers analyzed epigenetic signatures in blood cells from 374 individuals enrolled in the European Prospective Investigation into Cancer and Nutrition. EPIC, as it's known, is a massive study aimed at linking diet, lifestyle, and environmental factors to the incidence of cancer and other chronic diseases. Half of the group consisted of people who went on to develop colon or breast cancer 5 to 7 years after first joining the study, whereas the other half remained healthy. © 2010 American Association for the Advancement of Science.

Keyword: Drug Abuse; Genes & Behavior
Link ID: 17632 - Posted: 12.22.2012

By Liz Kowalczyk Health officials investigating the national fungal meningitis outbreak caused by tainted steroid injections had thought that the worst was over. The number of new cases was dwindling. Then came patients like Anna Adair. An avid gardener and dog-breeder, Adair was rolled into a Michigan emergency room in a wheelchair Nov. 15. She had been bedridden for days, and that morning a bolt of pain in her lower back had caused her to tumble to the bathroom floor. Doctors quickly reached a disturbing realization: An infection caused by black mold had infiltrated her spine, near where she had received an injection made by a Massachusetts pharmacy, and spread into the bone. It was not the ­meningitis that sickened hundreds of others in late summer and early fall, but part of a frightening second wave of ­fungal infections caused by contaminated drugs. Dozens more people have now been diagnosed with excruciating abscesses or inflamed nerves in their backs that are proving formidable to cure. In a health alert issued Thursday, the federal Centers for Disease Control and Prevention said it is worried that some patients with spinal infections may not even be aware of their condition because the symptoms mimic the very back pain they originally sought to treat with steroids. The agency is now recommending that doctors consider performing MRI scans to screen all patients who have persistent back pain and received steroids from one of three contaminated batches. Previously, it advised scanning just those with new or worsening pain. © 2012 NY Times Co.

Keyword: Pain & Touch
Link ID: 17631 - Posted: 12.22.2012

Analysis by Sheila Eldred This spring, it's likely there will be a new diet pill on the market. Belviq (lorcaserin) won approval from the FDA last spring, making it the first weight-loss drug approved in 13 years, and the DEA proposed this week that the drug be classified as a Schedule IV controlled substance. Belviq is an appetite suppressant. The new chemical entity works by activating the brain's response to serotonin. Serotonin is a neuro-transmitter known for evoking happy moods; some anti-depressants work by keeping serotonin levels elevated. Belviq works specifically with the serotonin receptors involved with appetite, according to Time. In trial, patients who took Belviq lost 3 to 3.7 percent more weight than those taking a placebo; after taking it for one or two years, 47 percent lost at least 5 percent of their body weight (compared to 23 percent of those who took a placebo), WebMD reports. Another new weight loss drug, Qsymia, is already on the market, although sales have been slow. Belviq is approved for obese people and overweight people who have another weight-related disease or risk factor. Side effects include headache, dizziness, fatigue, nausea, dry mouth and constipation; in patients with diabetes, additional side effects include low blood sugar, back pain, and coughing. © 2012 Discovery Communications, LLC.

Keyword: Obesity
Link ID: 17630 - Posted: 12.22.2012

Fighting may have shaped the evolution of the human hand, according to a new study by a US team. The University of Utah researchers used instruments to measure the forces and acceleration when martial artists hit a punch bag. They found that the structure of the fist provides support that increases the ability of the knuckles to transmit "punching" force. Details have been published in the Journal of Experimental Biology. "We asked the question: 'can you strike harder with a fist than with an open palm?'," co-author David Carrier told BBC News. "We were surprised because the fist strikes were not more forceful than the strikes with the palm. In terms of the work on the bag there is really no difference." Of course, the surface that strikes the target with a fist is smaller, so there is more stress from a fist strike. "The force per area is higher in a fist strike and that is what causes localised tissue damage," said Prof Carrier. BBC © 2012

Keyword: Aggression; Evolution
Link ID: 17629 - Posted: 12.22.2012

By RON LIEBER Insurance covers more mental health care than many people may realize, and more people will soon have the kind of health insurance that does so. But coverage goes only so far when there aren’t enough practitioners who accept it — or there aren’t any nearby, or they aren’t taking any new patients. In the days after the Newtown, Conn., school shooting, parents and politicians took to the airwaves to make broad-based proclamations about the sorry state of mental health care in America. But a closer look reveals a more nuanced view, with a great deal of recent legislative progress as well as plenty of infuriating coverage gaps. The stakes in any census of mental health insurance coverage are high given how many people are suffering. Twenty-six percent of adults experience a diagnosable mental disorder in any given year, and 6 percent of all adults experience a seriously debilitating mental illness, according to the National Institute of Mental Health. Twenty-one percent of teenagers experience a severe emotional disturbance between the ages of 13 and 18. According to this year’s Society for Human Resource Management survey of 550 employers of all sizes, including nonprofits and government entities, 85 percent offer at least some mental health insurance coverage. A 2009 Mercer survey found that 84 percent of employers with more than 500 employees covered both in-network and out-of-network mental health and substance abuse treatments. © 2012 The New York Times Company

Keyword: Depression
Link ID: 17628 - Posted: 12.22.2012

Julian Richards, deputy editor, newscientist.com Let's take it from the top again... Human singing stars these days rely on Auto-Tune technology to produce the right pitch, but this songbird does it the old way - by listening out for its own mistakes. And it's also smart enough to ignore notes that are too far off to be true. Brains monitor their owners' physical actions via the senses, and use this feedback to correct mistakes in those actions. Many models of learning assume that the bigger the perceived mistake, the bigger the correction will be. Samuel Sober at Emory University in Atlanta, Georgia, and Michael Brainard of the University of California, San Francisco, suspected that the system is a bit cleverer than that - otherwise, for instance, a bird might over-correct its singing if it confused external sounds with its own voice, or if its brain made a mistake in processing sounds. They decided to fool Bengalese finches into thinking that they were singing out of tune, and measured what happened at different levels of this apparent tone-deafness. To do this, they fitted the birds with the stylish headphones shown in the photo above and fed them back the sound of their own singing, processed to sound sharper than it really was. The researchers sharpened the birdsong by degrees ranging from a quarter-tone to one-and-a-half tones. They found that the birds learned to "correct" their pitch more accurately and more quickly when they heard a smaller mistake than when they heard a large one. It was also clear that the bird brains took "errors" seriously when they fell within the normal range of pitches in the bird's song: the birds seemed to ignore errors outside this range. © Copyright Reed Business Information Ltd

Keyword: Hearing; Learning & Memory
Link ID: 17627 - Posted: 12.22.2012

Posted by Monya Baker Plaques and tangles pockmark the brains of people with Alzheimer’s disease. The extracellular protein amyloid-β makes plaques, and the intracellular protein tau makes tangles, but how exactly these might kill neurons is unclear. Work presented at the annual meeting of the American Society for Cell Biology in San Francisco, California, this week starts to connect some of these dots. George Bloom, of the University of Virginia in Charlottesville, and his colleagues began by following up on work that neurons exposed to amyloid-β die not from direct poisoning, but because amyloid-β prompts inappropriate cell behaviour. They re-enter the cell cycle but never divide, and die instead. “The framework of the process has now been defined,” he says. “We think we’ve stumbled upon one of the seminal events in the transition of healthy neurons into Alzheimer neurons.” The work identifies several potential very early biomarkers of Alzheimer’s disease and suggests new ideas to treat it. Within 24 hours of exposing neurons to amyloid-β, Bloom and his students could see that the neurons had begun to duplicate DNA — an early preparation for division. When they repeated the experiment with neurons that lacked tau, however, the neurons did not respond this way. Guessing that a cell-signaling cascade could explain these observations, Bloom’s then-student Matt Seward began listing potential protein mediators. He identified enzymes called kinases that had been implicated in Alzheimer’s disease, cell-cycle regulation or tau modification. © 2012 Nature Publishing Group

Keyword: Alzheimers
Link ID: 17626 - Posted: 12.21.2012

By Daisy Yuhas At least 1 in 4000 infants is born without a corpus callosum. This powerful body of connective white matter serves as the primary bridge between the brain’s hemispheres, allowing us to rapidly integrate complex information. “It’s a hidden disability,” says University of California Institute of Technology psychologist Lynn Paul. Many born without this structure go undiagnosed for years—only neuroimaging can confirm the agenesis, or failed development, of this brain area. Instead people are diagnosed with disorders such as autism, depression, or ADHD. People born without a corpus callosum face many challenges. Some have other brain malformations as well—and as a result individuals can exhibit a range of behavioral and cognitive outcomes, from severe cognitive deficits to mild learning delays. Paul is also the founding president of the National Organization of Disorders of the Corpus Callosum, a non-profit that offers resources and support to those affected and their families. She believes psychologists and neuroscientists can learn much from this disorder, including how varied biological problems can result in the same behavioral outcomes. But what may be most remarkable is how the acallosal brain adapts to its limitations and finds new connective routes. Precisely how the brain does this is a biological mystery, but there are several possible routes of compensation, which effectively re-route the brain’s connections in novel ways. Similarly, each individual born with this condition must find his or her own way to overcome unique challenges. As is clear from their stories, individuals often find strength in one another and in sharing their experiences. © 2012 Scientific American

Keyword: Laterality; Language
Link ID: 17625 - Posted: 12.21.2012

By ADAM NAGOURNEY LOS ANGELES — Let Colorado and Washington be the marijuana trailblazers. Let them struggle with the messy details of what it means to actually legalize the drug. Marijuana is, as a practical matter, already legal in much of California. A man panhandled for pot recently on the boardwalk in Venice Beach, Calif., where a variety of marijuana-themed items are for sale. No matter that its recreational use remains technically against the law. Marijuana has, in many parts of this state, become the equivalent of a beer in a paper bag on the streets of Greenwich Village. It is losing whatever stigma it ever had and still has in many parts of the country, including New York City, where the kind of open marijuana use that is common here would attract the attention of any passing law officer. “It’s shocking, from my perspective, the number of people that we all know who are recreational marijuana users,” said Gavin Newsom, the lieutenant governor. “These are incredibly upstanding citizens: Leaders in our community, and exceptional people. Increasingly, people are willing to share how they use it and not be ashamed of it.” Marijuana can be smelled in suburban backyards in neighborhoods from Hollywood to Topanga Canyon as dusk falls — what in other places is known as the cocktail hour — often wafting in from three sides. In some homes in Beverly Hills and San Francisco, it is offered at the start of a dinner party with the customary ease of a host offering a chilled Bombay Sapphire martini. © 2012 The New York Times Company

Keyword: Drug Abuse; Development of the Brain
Link ID: 17624 - Posted: 12.21.2012

Continued high use of marijuana by the nation's eighth, 10th and 12th graders combined with a drop in perceptions of its potential harms in this year's Monitoring the Future survey, an annual survey of eighth, 10th, and 12th-graders conducted by researchers at the University of Michigan. The survey was carried out in classrooms around the country earlier this year, under a grant from the National Institute on Drug Abuse (NIDA), part of the National Institutes of Health. The 2012 survey shows that 6.5 percent of high school seniors smoke marijuana daily, up from 5.1 percent five years ago. Nearly 23 percent say they smoked it in the month prior to the survey, and just over 36 percent say they smoked within the previous year. For 10th graders, 3.5 percent said they use marijuana daily, with 17 percent reporting past month use and 28 percent reporting use in the past year. The use escalates after eighth grade, when only 1.1 percent reported daily use, and 6.5 percent reported past month use. More than 11 percent of eighth graders said they used marijuana in the past year. The Monitoring the Future survey also showed that teens' perception of marijuana’s harmfulness is down, which can signal future increases in use. Only 41.7 percent of eighth graders see occasional use of marijuana as harmful; 66.9 percent see regular use as harmful. Both rates are at the lowest since the survey began tracking risk perception for this age group in 1991. As teens get older, their perception of risk diminishes. Only 20.6 percent of 12th graders see occasional use as harmful (the lowest since 1983), and 44.1 percent see regular use as harmful, the lowest since 1979.

Keyword: Depression; Development of the Brain
Link ID: 17623 - Posted: 12.21.2012

By Yevgeniy Grigoryev and Spoonful of Medicine The recent tragedy in Newtown, Connecticut, perpetrated by 20 year-old Adam Lanza, has intensified the discussion about how mental health is handled and documented in the US. Officials have not provided information about Lanza’s motivation and state of mind, and many are rightfully quick to point out that it is wrong to equate mental illness with the fatal sociopathic actions of a small group of individuals. The conversation about access to mental health care should, however, take into account new data showing an increasing contribution of mental and behavioral disorders to deterioration in the health-related quality of life among teenagers in the US and Canada over the last two decades, and increases elsewhere around the globe. The estimation of ‘years lived with disabilities’, or YLDs, is used as a collective metric to determine how much a particular disorder deprives the population of healthy years of life during a particular window of time. In 2010 just as in 1990, depression ranked as the number two contributor of YLDs, affecting 4% of the global population, eclipsed only by back pain that affected almost 10% of population worldwide. Among 10 to 14 year olds, the top contributor worldwide is iron deficiency. Asthma had been the largest contributor to YLDs for youths in that age range in the US and Canada in 1990, but the study published in The Lancet on Thursday led by researchers at the Institute of Health Metrics and Evaluation (IHME) at the University of Washington, Seattle showed that in this group depression surpassed asthma to claim the number one spot in 2010. In that group, the collective number of ‘years lost to disability’ grew from about 140,000 in 1990 to almost 180,000 in 2010, a 30% increase. Notably, global figures for the same age group show that the number of years lost to disability from depression grew from 4.9 million in 1990 to 5.5 million in 2010, a 13% increase as shown in the graphs below. © 2012 Scientific American

Keyword: Depression; Development of the Brain
Link ID: 17622 - Posted: 12.21.2012

By Scicurious Depression is a disease with a difficult set of symptoms. Not only are the symptoms difficult to describe (how do you really describe anhedonia, before you know the word for it?), symptoms of depression manifest in different ways for different people. One person will eat more, sleep all the time, move slowly. Another will eat almost nothing, never sleep, and be irritable and nervous. They are both depressed. The only universal symptom is the feeling of…depression, and the need for successful treatment. Treatments which often take several weeks to work, are often ineffective, and which come with a host of side effects. So I was particularly intrigued when Nature published two papers this week looking at the role of dopamine in depressive-like behavior. What I particularly like is that these two papers have somewhat opposite results, due to different behavioral methods, something which I think highlights some of the problems associated with studying depression. Ed Yong covered both of the studies together fabulously over at Not Exactly Rocket Science, but I’d like to look at them both separately, to take a deeper look at each one, see what they’ve achieved, and what other questions they raise. Today we are on the second of the two papers, one which has a similar angle to the first paper, but an entirely different result. Yesterday’s paper looked at how changes in dopamine cell firing from the ventral tegmental area (which projects to areas like the prefrontal cortex and the nucleus accumbens) can impact depressive-like behaviors in mice and rats. Today’s paper looks at the ventral tegmental area as well, but instead of cutting on or turning “off” cell firing, the authors of this study looked at different types of neuronal activity, and the effects in socially defeated mice. © 2012 Scientific American

Keyword: Depression
Link ID: 17621 - Posted: 12.19.2012

Daniel Cressey The search for a drug to treat Alzheimer’s disease could be being undermined by flaws in a test used in clinical trials to assess patients. And though few experts would blame the test for the recent failures of potential new drugs, a major push is now on to produce more sensitive ways of measuring the progress of the disease. During the past few years, a number of clinical trials have produced disappointing results for high-profile drugs, and some pharmaceutical companies have abandoned Alzheimer’s disease altogether, frustrated by the high costs and difficulty of producing a drug with a measurable effect. Jeremy Hobart, a neurologist at the Plymouth University Peninsula Schools of Medicine and Dentistry, UK, says that flaws in the ADAS-Cog test could be partly responsible. In many trials branded ‘failures’, the ADAS-Cog (Alzheimer’s Disease Assessment Scale — Cognitive Behaviour section) has been used as the key test of whether a drug is working. The test scores patients on 11 components using a variety of tasks relating to memory, language and praxis (the planning of movement to achieve a purpose), such as word recognition and remembering instructions. Lower scores indicate better cognitive performance and so less severe disease. There is, says Hobart, an argument that any study that has used ADAS-Cog may have underestimated changes in and differences between patients given the drug and controls. In two papers in Alzheimer’s & Dementia, Hobart and his colleagues detail flaws in the test that undermine its utility. © 2012 Nature Publishing Group

Keyword: Alzheimers
Link ID: 17620 - Posted: 12.19.2012