Links for Keyword: Movement Disorders

Follow us on Facebook and Twitter, or subscribe to our mailing list, to receive news updates. Learn more.


Links 21 - 40 of 108

By Sandra G. Boodman, For the first decade of his life, every doctor who saw Jack DeWitt inevitably zeroed in on the harrowing circumstances of his premature birth. Delivered by emergency Caesarean section in December 1999, doctors universally ascribed his developmental problems to his being born six weeks early, said his mother, Ruth DeWitt. “It always came back to that.” When Jack’s walking became odd at age 5, doctors chalked it up to a mild form of cerebral palsy that can occur in children born too soon. “We were okay with it,” his mother said, because mild cerebral palsy would not “affect the length of his life or his enjoyment of it.” Jack’s parents were also reassured by his ability to catch up; with help, he mastered various skills: jumping, walking and writing in cursive. But by age 10, when his ability to walk badly deteriorated, a reevaluation by his doctors resulted in a very different diagnosis and prognosis. “We had all those years of feeling that he was a normal, healthy kid with some challenges,” his mother recalled. Discovering what was really wrong has been a heavy blow, magnified by Jack’s perceptive awareness of its implications. Ruth DeWitt, who lives with her family in Howell, Mich., outside Ann Arbor, was in the hospital undergoing a test for preeclampsia, or pregnancy-induced hypertension, when she began hemorrhaging, a sign of placental abruption. The life-threatening condition occurs when the placenta prematurely detaches from a woman’s uterus. Rushed into surgery, Jack was born weighing 3 pounds, 9 ounces, and was transferred to the neonatal intensive care unit at the University of Michigan Medical Center. Small but strong, he needed oxygen but no ventilator, and he came home 15 days later. © 1996-2012 The Washington Post

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 17615 - Posted: 12.18.2012

By ANDREW POLLACK An experimental drug preserved and even improved the walking ability of boys with Duchenne muscular dystrophy in a clinical trial, raising hopes that the first effective treatment for the disease may be on the horizon. Boys with the disease who received the highest dose of the drug had a slightly improved ability to walk after 48 weeks of treatment, the drug’s developer, Sarepta Therapeutics, announced Wednesday. By contrast, the boys who received a placebo suffered a sharp decline in how well they could walk. The drug, called eteplirsen, also appeared to restore levels of the crucial protein that muscular dystrophy patients lack to about half of normal levels, Sarepta said. “I think this changes the entire playing field for muscular dystrophy,” said Dr. Jerry R. Mendell, director of the gene therapy and muscular dystrophy programs at Nationwide Children’s Hospital in Columbus, Ohio, and the lead investigator in the trial. There are many caveats. The trial had only 12 patients, with only four receiving the high dose and four the placebo, and the data has not been reviewed by experts. It is also unclear how long the effects of the drug would last or if safety issues would arise with longer treatment. Also, eteplirsen would be appropriate for only about 13 percent to 15 percent of Duchenne patients, those with the particular genetic mutation the drug is meant to counteract. However, a similar approach might work for some other mutations. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17331 - Posted: 10.04.2012

by Jessica Hamzelou When something goes wrong in your brain, you'd think it would be a good idea to get rid of the problem. Turns out, sometimes it's best to keep hold of it. By preventing faulty proteins from being destroyed, researchers have delayed the symptoms of a degenerative brain disorder. SNAP25 is one of three proteins that together make up a complex called SNARE, which plays a vital role in allowing neurons to communicate with each other. In order to work properly, all the proteins must be folded in a specific way. CSP alpha is one of the key proteins that ensures SNAP25 is correctly folded. Cells have a backup system to deal with any misfolded proteins – they are destroyed by a bell-shaped enzyme called a proteasome, which pulls the proteins inside itself and breaks them down. People with a genetic mutation that affects the CSP alpha protein – and its ability to correctly fold SNAP25 – can develop a rare brain disorder called neuronal ceroid lipofuscinosis (NCL). The disorder causes significant damage to neurons – people affected gradually lose their cognitive abilities and struggle to move normally. To find out what role proteasomes might play in NCL, Manu Sharma and his colleagues at Stanford University in California blocked the enzyme in mice that were bred to lack CSP alpha. "We weren't sure what would happen," says Sharma. Either the misfolded SNAP25 would accumulate and harm the cells, or some of the misfolded proteins may work well enough to retain some of their function. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17173 - Posted: 08.16.2012

by Nicola Guttridge Whether a tree branch or a computer mouse is the target, reaching for objects is fundamental primate behaviour. Neurons in the brain prepare for such movements, and this neural activity can now be deciphered, allowing researchers to predict what movements will occur. This discovery could help us develop prosthetic limbs that can be controlled by thought alone. To find out what goes on in the brain when we reach for things, biomedical engineers Daniel Moran and Thomas Pearce at Washington University in St Louis, Missouri, trained two rhesus macaques to participate in a series of exercises. When the monkeys reached for items, electrodes measured the activity of neurons in their dorsal premotor cortex, a region of the brain that is involved in the perception of movement. The monkeys were trained to reach for a virtual object on a screen to receive a reward. In some tasks the monkeys had to reach directly for an object, in others they had to reach around an obstacle to get to the target. Impulsive grab Moran and Pearce managed to identify the neural activity corresponding with several aspects of the planned movement, such as angle of reach, hand position and the final target location. The findings could one day allow the design of prosthetic limbs that can be controlled with thought alone, which is "one of the reasons we did the study", says Moran. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 17073 - Posted: 07.21.2012

By Scicurious Think about what happens when you walk. Really THINK about it. What does it take to walk? Well, your feet and legs have to move (far more complicated than they look), which means your muscles have to move, which means your nerves have to control your muscles, which means your brain has to send the signals in the first place. All of this is based on further information, knowing where you are in space and where you’re going, how fast you need to get there. And then there’s even more! How do you know where you are? How do you know how fast you’re going? How do you know which direction you’re headed? And behind all of this are thousands and millions of neurons firing, together and separately. And underlying THAT are thousands of biochemical processes which allow the neurons to fire… …now take that walking speed, and make it a run. The sheer number of neurobiological processes and number of things that need to happen to make you walk into your workplace every morning is the kind of thing that makes neuroscientists stop in their tracks with wonder. And today, we’re going to talk about a paper that may have worked out a tiny piece of how the brain might deal with things like increased speed. How does your brain keep up with your feet? By running a little faster. To understand how this works. We need to talk about two major things: place neurons, and oscillatory networks. © 2012 Scientific American

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 18: Attention and Higher Cognition
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 14: Attention and Consciousness
Link ID: 17059 - Posted: 07.18.2012

By Sandra G. Boodman, Liisa Ecola lay on the sofa in the living room of her Capitol Hill home counting the hours until she could see a specialist who, she fervently hoped, would tell her why she could no longer keep her eyes open. For several months, the 42-year-old transportation policy researcher for Rand had been squinting, even in the dark. Her puzzled optometrist had suggested she consult a neuro-ophthalmologist, a doctor who specializes in diseases of the eye originating in the central nervous system. Ecola had waited weeks to get an appointment, which was scheduled for Dec. 15, 2010. But the day before, Ecola recalled, “I opened my laptop and my eyes snapped shut.” To her horror, she discovered that her eyes would stay open only for a few minutes at a time. Panicked, she called the specialist to confirm the appointment, only to discover that she wouldn’t be seeing him at all. The office had no record of her. “I was really scared,” said Ecola, who called it the lowest moment in her quest for a diagnosis. “I was convinced I had a brain tumor.” Her problem turned out to be far less serious and far more easily treated. The following day she lucked into an appointment with another specialist, who explained the odd constellation of symptoms that had left her unable to leave her house. For several years, Ecola had suffered an unexplained, intermittent facial tic, in which she scrunched up her face as if she were tasting something awful. Because it seemed linked to stress, Ecola consulted a behavioral therapist in an effort to banish it through habit reversal training — using relaxation exercises and making a conscious effort to stop the tic. Until early 2010, the treatment usually worked, and Ecola seemed able to control it. © 1996-2012 The Washington Post

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 7: Vision: From Eye to Brain
Link ID: 16696 - Posted: 04.24.2012

By LISA SANDERS, M.D., Columnist On Thursday, we challenged Well readers to figure out the diagnosis for a 27-year-old woman with an odd walk and slowly progressive weakness of her hips and thighs. The correct diagnosis is… Adult-onset Tay-Sachs disease The first person to get it right was Jason Maley, a third-year medical student at Tulane University. His answer came in just after 1 a.m., an hour after the case was posted. He says that all the clues were there; he just had to put it all together. He’s planning to go into internal medicine. (I certainly hope that he will!) Tay-Sachs is an inherited disease in which the inability to get rid of discarded parts of the cell membrane causes the death of certain nerve cells. There are several forms of the disease. The most common affects infants. Babies born with this version of the disease usually die by age 4. Another form of the disease affects children who usually die before reaching adulthood. Late-onset Tay-Sachs, the form of the disease this patient has, doesn’t manifest itself until adolescence or young adulthood and causes a slow loss of strength and coordination. While the form seen in children was first described over a century ago, this version wasn’t recognized until the 1970s. Patients with this form of the disease can get rid of some but not all of the fatty components of the cell wall and so have a much slower rate of cell death and disability. The degree of disability varies widely in this group, and there are patients who have the disease but appear to be completely asymptomatic. For many with this disease, life expectancy is normal, but most eventually require a wheelchair. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16621 - Posted: 04.07.2012

By ABIGAIL ZUGER, M.D. Just when it seems long past time for the age of memoir to be over — just when it seems impossible that any ailing person with literary inclinations could find anything new to say about illness, and the list of not-to-be-missed “patients are people too” books should be closed and locked — yet another book comes along. And despite all the above, no one with even a passing interest in the experience of illness should miss Robert C. Samuels’s “Blue Water, White Water,” a memoir drafted about 30 years ago and published without fanfare a few months ago; it stands head and shoulders above the crowd. The details are slightly obsolete, to be sure: Mr. Samuels endured his many months of dire illness tethered to a respirator back in the 1980s, the Stone Age of modern intensive-care treatment. Nonetheless, his story from the wrong end of the tubes is timeless; the technology may evolve briskly, but the experience changes glacially, if at all. A former beat reporter for The New York World-Telegram & Sun, Mr. Samuels covers his own story like a pro. He was healthy, 44, just returned from a trip around the world in December 1981, when he got out of bed one morning with a weak left leg. He wandered into the local emergency room half convinced he was imagining things. By the next day he was completely paralyzed with a respirator breathing for him: Guillain-Barré syndrome, an autoimmune disease, was rapidly and efficiently stripping his motor nerves of their myelin sheathing, short-circuiting them all. Only his eyes still moved a little, from left to right. Nothing was wrong with his brain. © 2012 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 16511 - Posted: 03.13.2012

Scottish research has shown it could be possible to reverse the muscle damage seen in children with a form of motor neurone disease. Spinal muscular atrophy (SMA) - 'floppy baby syndrome' - is the leading genetic cause of death in children. It affects one in 6,000 births, but 50% of those with the most severe form die before the age of two. The University of Edinburgh mouse study suggests a drug could boost levels of a protein and so reverse muscle damage. Children with SMA experience progressive muscle wastage, loss of mobility and motor function. Now 13, he was diagnosed at the age of three. "My wife first knew there was something wrong when he was two. He was just walking funnily. "But he wasn't diagnosed until the third time she took him to the doctors. "Initially there was a question as to whether it was SMA or muscular dystrophy. "We'd heard of muscular dystrophy - but not SMA. BBC © 2012

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 16437 - Posted: 02.27.2012

By Scicurious Humans walk well. More to the point, we walk EFFICIENTLY. As we evolved to walk upright, we also evolved to do so with great economy, expending fewer calories at an optimal walking pace, but then expending more calories when we either speed up or slow down. We also may be economically efficient runners as well as walkers, we’re average for mammals, but our long legs and ability for those legs to take repeated strain suggests we may be on the efficient end of primates (and we’re some of the BEST long distance runners on the planet, so we can preen a bit over that one). The jury is still out on running, but as far as walking goes we are the most efficient at a moderate speed (roughly 5 km/hr, or 3.1 miles/hour for men, a relatively brisk walk of 20 min a mile). So we’re good walkers, or at least economic ones. But the question is, what MAKES for this efficiency? How exactly are we burning fewer calories at a specific walking pace? Ideally, this means that our muscles, like our bodies overall, are at their most efficient at a moderate walking pace. The calories burned over time are the result of the total metabolic rate of all the muscles that produce locomotion. So since your metabolism is minimized at a moderate walking pace, creating the most efficiency, it would make theoretical sense that your individual MUSCLES are also minimizing their metabolism at that moderate walking pace, and the cumulative effect is one of energy efficiency. Theoretically, it makes sense. At a certain pace, you’re overall burning fewer calories and not working as hard, so your individual muscles must also not be working as hard. Right? Well…possibly wrong. © 2012 Scientific American,

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16204 - Posted: 01.03.2012

by Curtis Abraham, Uganda Large areas of northern Uganda are experiencing an outbreak of nodding syndrome, a mysterious disease that causes young children and adolescents to nod violently when they eat food. The disease, which may be an unusual form of epilepsy, could be linked to the parasitic worm responsible for river blindness, a condition that affects some 18 million people, most of them in Africa. The current outbreaks are concentrated in the districts of Kitgum, Pader and Gulu. In Pader alone, 66 children and teenagers have died. More than 1000 cases were diagnosed between August and mid-December. Onchocerca volvulus, a nematode worm that causes river blindness, is known to infest all three affected districts. Nearly all the children with nodding syndrome are thought to live near permanent rivers, another hint of a connection with river blindness. The link is not clear cut, though. "We know that [Onchocerca volvulus] is involved in some way, but it is a little puzzling because [the worm] is fairly common in areas that do not have nodding disease," says Scott Dowell, who researches paediatric infectious diseases and is lead investigator into nodding syndrome with the US Centers for Disease Control and Prevention. There is no known cure for nodding syndrome, so Uganda's Ministry of Health has begun using anticonvulsants such as sodium valproate to treat its signs and symptoms. Meanwhile the disease is continuing to spread, say Janet Oola, Pader's health officer, and Sam William Oyet, the district's medical entomology officer. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 16177 - Posted: 12.23.2011

By Lonnae O’Neal Parker, That morning, I noticed first that I couldn’t spit. I was brushing my teeth, but I couldn’t close my lips around the toothbrush, and my mouth didn’t seem to work right. Weird, I thought, but I quickly put it out of my mind. I was on assignment for The Post and probably I was just tired from the overnight drive from Prince George’s County to Greensboro, N.C. Perhaps it was the two glasses of wine a couple of nights before. Maybe it was the flu. Whatever it was, I was sure I didn’t have time for it. I was traveling to Atlanta with two guys I was writing about, and as we grabbed breakfast before the second leg of our drive, my weird-face feeling intensified. Then my right eye began to ache, and a sudden fear iced my spine. I stepped outside the restaurant to stare at my reflection in the car window, and I couldn’t process what I was seeing. I couldn’t move the right side of my face, and my eye ached because I couldn’t close it. The parking lot started to swim, and I willed myself not to faint. “Something’s wrong with my face,” I told the guys haltingly. “I have to go to the emergency room when we get to Atlanta.” But they insisted on taking me immediately in Greensboro. I’m glad they did. “My face is paralyzed, and I can’t blink. I think I’m having a stroke,” I told the receptionist at the Moses Cone Urgent Care Center, though it all felt so surreal. I’m only 44, and I’m healthy! © 1996-2011 The Washington Post

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15859 - Posted: 10.01.2011

By JoNel Aleccia Health writer A cluster of cases of a rare illness that can lead to nerve damage and paralysis has been identified along a small stretch of the United States-Mexico border. An outbreak of food poisoning is the likely culprit, health officials in the two countries said. At least two dozen people in Yuma County, Ariz., and San Luis Rio Colorado, Sonora, Mexico, have been diagnosed with Guillain-Barré Syndrome in the past month, with some left drastically impaired by the illness that triggers the body's auto-immune reaction. “It’s really attacking the nerves,” said Shoana Anderson, office chief of infectious disease at the Arizona Department of Health Services. “All of the patients I’ve seen are not able to walk.” Most of the victims, including 17 from Mexico and seven from the U.S., are adults who range in age from 40 to 70, although younger people also have been affected, Anderson said. Some patients have muscle weakness in their upper bodies as well as in their legs, she added. It's not clear how quickly they may recover. Guillian-Barré Syndrome, or GBS, typically affects only about 1 in 100,000 people, according to government health statistics, so a cluster of 24 cases is cause for alarm, officials said. Although the condition often resolves on its own, recovery can be long and painful. And in rare cases, the illness can cause permanent disability and even death. © 2011 msnbc.com

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15599 - Posted: 07.26.2011

By Laura Sanders When a woman born without limbs watches someone else sew, copycat regions in her brain activate even though she can’t hold a needle herself. Additional brain regions also lend support, demonstrating how flexible the brain is when it comes to observing and understanding the actions of others. Scientists have known for over a decade about the mirror system, a network of brain regions usually activated by watching and performing an action. But just how the brain smoothly and quickly intuits what other people are doing, particularly when the action isn’t something the observer can do, has been unclear, says study coauthor Lisa Aziz-Zadeh of the University of Southern California in Los Angeles. In the study, a middle-aged, healthy woman born with no arms and legs underwent brain scans as she watched videos of people performing actions such as holding and eating an apple slice, sewing with a needle and tapping a finger. Actions that the woman was capable of performing herself activated the mirror system, including parts of the brain that control movement. Mirror areas kicked in even for tasks the woman accomplishes in a different way, such as picking up food using her mouth instead of hands. (The participant had prosthetics briefly as a teenager but hadn’t used them in the past 40 years.) When the woman witnessed actions that were impossible for her, such as using scissors, her brain’s mirror system still kicked in, but additional brain regions were recruited to help. These extra regions aren’t normally needed when people watch a task they’re able to perform, the researchers write in an upcoming Cerebral Cortex. These regions are thought to be involved in a process called “mentalizing,” in which a person tries to understand what someone else is thinking. © Society for Science & the Public 2000 - 2011

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 10: Vision: From Eye to Brain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 7: Vision: From Eye to Brain
Link ID: 15564 - Posted: 07.16.2011

By LISA SANDERS, M.D. Symptoms A healthy 10-year-old girl told her mother that she was losing a lot of hair when she showered. Her mother didn’t give it much thought, until one morning when she saw for herself how much hair remained on her hands after making a ponytail for her daughter. Looking at her child’s head in the sunlight later that morning, the mother thought that maybe her hair was thinning. She took her to see Dr. Kathryn Italia, their pediatrician in Exton, a suburb of Philadelphia, that afternoon. The Exam Although the child seemed well, the doctor was concerned. The girl’s mother, who had two other children, was not a big worrier. There were no other symptoms, but the mother reported that her daughter might have been a little more tired lately. Italia examined the child but found nothing unusual. Possible Diagnoses Thyroid disease: Can cause hair loss and fatigue. Lupus and other immune-system diseases: Can also cause hair loss. Metabolic disease: Can disrupt any of the multiple processes the body uses to get energy from food. Testing of blood, kidneys and liver will often reveal its presence. Results All tests were unremarkable except for two enzymes (ALT and AST) that signal liver injury and were four times higher than normal. The Follow-Up Italia ordered an ultrasound of the liver and a repeat of the liver-function tests. (A mild viral infection can frequently cause a transient elevation in these enzymes.) Additional tests looked for other common infections and diseases that can cause abnormal liver enzymes in children: Epstein-Barr virus (the infectious cause of mononucleosis); viral hepatitis; celiac disease, a disorder in which the immune system attacks the small intestine in response to a food component known as gluten. Results The tests revealed that only the liver enzymes were abnormal. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15198 - Posted: 04.09.2011

By KAREN BARROW It is classified as a rare disease, but the chronic condition called Charcot-Marie-Tooth is one of the most common inherited nerve-related disorders, with an estimated 150,000 patients in the United States. It can be devastating to patients and their families, with crippling effects on balance and the ability to walk and grasp objects. Nor does it help that few people have heard of it, unless they are directly affected. “It’s like the hidden secret,” said Allison Moore, chief executive of the Hereditary Neuropathy Foundation, who has the disease. “And when you mention, ‘I have C.M.T.,’ people look at you like you have three heads.” The disease — named for Jean-Martin Charcot, Pierre Marie and Howard Henry Tooth, the researchers who first described it in 1886 — is actually a group of neurodegenerative conditions that gradually degrade the nerves in the feet, legs, arms and hands, usually starting in childhood. There is no medical treatment, though orthopedic braces and corrective surgery can help. © 2011 The New York Times Company

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 15174 - Posted: 04.05.2011

Alison Abbott There is no cure for the group of hereditary muscle-wasting diseases known as muscular dystrophy. That is particularly alarming because one of its commonest forms — type 1 myotonic dystrophy — becomes more serious as it passes down the generations, manifesting earlier and acquiring pernicious extra symptoms, such as delays to mental development. A group of French scientists have now unravelled molecular pathways that may be responsible for some symptoms of type 1 myotonic dystrophy. They used a controversial source of material: disease-specific human embryonic stem (hES) cell lines. They hope that their results, published online today in Cell Stem Cell1, will influence a French political debate that threatens to restrict such work. The French Senate will vote on the issue on 5 April, in the first reading of new legislation to update the country's bioethics law (see France mulls embryo research reform). Type 1 myotonic dystrophy results from a defect in just one gene — dystrophia myotonica-protein kinase (DMPK) — but that damage affects the expression of other healthy genes. The team of researchers, led by Cécile Martinat, a geneticist at the Institute for Stem Cell Therapy in Evry, identified two such genes that are suppressed in the disease. They showed that the suppression prevented neurons from efficiently building connections with muscle cells. Unlike in most genetic diseases, the damaged DMPK gene is not mutated. Instead, its code is interrupted by a long and unstable string of 'triplet repeats', in which three of the four nucleotides that make up DNA repeat themselves more than fifty times. The string of repeats tends to get longer with each generation. © 2011 Nature Publishing Group

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 7: Life-Span Development of the Brain and Behavior
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 13: Memory, Learning, and Development
Link ID: 15163 - Posted: 04.02.2011

by Helen Thomson Too much of it will make you go blind – or so you might have been told. But for some, masturbation might have a real clinical benefit: it can ease restless leg syndrome (RLS). The insight could provide sweet relief for the 7 to 10 per cent of people in the US and Europe who suffer from the condition. RLS is a distressing neurologic disorder characterised by an urge to move the legs. It is usually associated with unpleasant sensations in the lower limbs such as tingling, aching and itching. The exact causes of RSL have yet to be pinpointed, but brain autopsies and imaging studies suggest one contributing factor is an imbalance of dopamine – a hormonal messenger that, among other things, activates the areas of the brain responsible for pleasure. It is suspected that dopamine imbalance is responsible for some of the symptoms of Parkinson's disease. Drugs that increase dopamine have been shown to reduce symptoms of RLS when taken at bedtime and are considered the initial treatment of choice. Although such drugs provided significant improvement of symptoms for a 41-year-old man with RLS, he found an even better treatment – complete relief after masturbation or sex. Luis Marin and colleagues at the Federal University of São Paulo, Brazil, who report on the novel treatment this month in Sleep Science, speculate that the release of orgasm-related dopamine might play a role in the alleviation of symptoms. © Copyright Reed Business Information Ltd.

Related chapters from BP7e: Chapter 14: Biological Rhythms, Sleep, and Dreaming; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 10: Biological Rhythms and Sleep; Chapter 5: The Sensorimotor System
Link ID: 15162 - Posted: 04.02.2011

Scientists are closer to understanding what triggers muscle damage in one of the most common forms of muscular dystrophy, called facioscapulohumeral muscular dystrophy (FSHD). FSHD affects about 1 in 20,000 people, and is named for progressive weakness and wasting of muscles in the face, shoulders and upper arms. Although not life-threatening, the disease is disabling. The facial weakness in FSHD, for example, often leads to problems with chewing and speaking. The new research was funded in part by the National Institutes of Health and appears in the journal Science. Until now, there were few clues to the mechanism of FSHD and essentially no leads for potential therapies, beyond symptomatic treatments, said John Porter, Ph.D., a program director at NIH's National Institute of Neurological Disorders and Stroke (NINDS). "This study presents a model of the disease that ties together many complex findings, and will allow researchers to test new theories and potential new treatments," Dr. Porter said. In the early 1990s, researchers found that FSHD is associated with a shortened DNA sequence located on chromosome 4. Experts predicted that discovery of one or more FSHD genes was imminent, but while a handful of candidate genes gradually emerged, none of them were found to have a key role in the disease. The mysteries surrounding FSHD deepened in 2002 when researchers, led by Silvere van der Maarel, Ph.D., at Leiden University in the Netherlands, found that the shortened DNA sequence on chromosome 4 is not enough to cause FSHD. They discovered that the disease occurs only among people who have the shortened DNA sequence plus other sequence variations on chromosome 4. That work was funded in part by NIH, the FSH Society and the Muscular Dystrophy Association.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 14375 - Posted: 08.20.2010

by Dolly J. Krishnaswamy Seven months ago, a 51-year-old woman known only to the public as patient LI1 suffered a severe stroke and lost her ability to communicate with the outside world. She couldn't even blink her eyes. But now, thanks to a new technology, the woman can write long, emotional e-mails to her loved ones just by sniffing. Like many quadriplegics, patient LI1's stroke damaged a region high up on her spinal column, paralyzing her from the neck down. But LI1's injury was so extensive that she also lost the ability to speak. Such patients are referred to as "locked-in" because they can't communicate with the outside world, even though their brain functions normally. Some can blink to answer simple yes or no questions or even string words together by picking out letters as someone recites them (as in the case of Jean-Dominique Bauby, author of The Diving Bell and the Butterfly). But this isn't an option for Patient LI1. So neurobiologist Noam Sobel of the Weizmann Institute of Science in Rehovot, Israel, turned to sniffing. He and colleagues had been studying the human sense of smell and had developed a device, which looks like the oxygen tubes patients wear in the hospital, that releases an odor when a subject sniffs forcefully. Sobel's team soon realized that the device could be configured to respond to various types of sniffing, such as sniffing harder or softer. And that meant it could have applications for locked-in patients. "We thought you could use this sniff to control anything, " Sobel says. "You could even fly a plane." © 2010 American Association for the Advancement of Science.

Related chapters from BP7e: Chapter 11: Motor Control and Plasticity; Chapter 9: Hearing, Vestibular Perception, Taste, and Smell
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 6: Hearing, Balance, Taste, and Smell
Link ID: 14291 - Posted: 07.27.2010