Links for Keyword: Movement Disorders
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Myasthenia gravis finding may lead to cure and shine light on other autoimmune diseases such as type 1 diabetes and rheumatoid arthritis GALVESTON, Texas-Researchers here have identified a critical element in the molecular process responsible for the neuromuscular disease myasthenia gravis. The discovery could lead to a possible cure for the muscle-weakening disease and to important insights into other autoimmune disorders such as rheumatoid arthritis, type 1 diabetes, lupus and multiple sclerosis. Myasthenia gravis, which afflicts about 36,000 Americans, causes a loss of muscle strength, which at worst can make even the smallest movements difficult. It occurs when the immune system mistakenly attacks molecules called acetylcholine receptors that muscle cells use to receive chemical signals from nerves. In an article appearing April 15 in The Journal of Clinical Investigation, scientists Premkumar Christadoss, Huan Yang, Elzbieta Goluszko, Teh-Sheng Chan and Mathilde Poussin, all of the University of Texas Medical Branch at Galveston (UTMB), pinpoint the specific part of the human acetylcholine receptor that evokes the strongest response from the human immune cells initiating such "friendly fire" attacks. Copyright © 2001, 2002 The University of Texas Medical Branch.
Related chapters from BP6e: Chapter 11: Motor Control and Plasticity; Chapter 15: Emotions, Aggression, and Stress
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 11: Emotions, Aggression, and Stress
Link ID: 1865 - Posted: 06.24.2010
Paralysis partly overcome by spinal stimulation. HELEN PEARSON A partially paralysed man has walked to the shops with the help of tiny electric shocks to his spine. With training, doctors hope to help other paraplegics walk again. Richard Herman and his colleagues helped a wheelchair-bound quadriplegic follow a walking rhythm by holding him over a moving treadmill. He paced 50 metres slowly - but the effort was exhausting. Zapping his spine while he was walking, slashed his pace time. The team planted pen-width electrodes in his lower back and gave low-level electrical stimulation1. "He began to walk 100, 200 metres," says Herman, of Arizona State University in Tempe. * Herman, R. et al. Spinal cord stimulation facilitates functional walking in a chronic incomplete spinal cord injured. Spinal Cord, 39, (2002). © Nature News Service / Macmillan Magazines Ltd 2002
A gene that causes a fatal childhood brain disorder can also cause adults to develop peripheral neuropathy, a condition resulting in weakness and decreased sensation in the hands and limbs, according to a study by researchers at the National Institutes of Health and other institutions. The study is the first to show that different mutations in the same gene cause the two seemingly unrelated disorders. Inherited peripheral neuropathies are a diverse group of disorders that cause loss of muscle tissue in the hands, feet, and lower legs of affected patients, usually starting in adulthood. Various genetic causes have been identified for Charcot-Marie-Tooth disease (CMT) (http://www.nature.com/ejhg/journal/v17/n6/pdf/ejhg200931a.pdf.), the broad category of inherited peripheral neuropathy that affects approximately 125,000 people in the United States. The peripheral nervous system consists of nerves that reside or extend outside of the brain and spinal cord. In the current study, the researchers determined that persons with a CMT-like neuropathy have a mutation in the same gene that causes Menkes disease, a severe brain disorder that begins in infancy and is fatal if not treated. This gene, called ATP7A, codes for a protein needed to move the trace metal copper between different compartments within the body's cells, or out of cells altogether. "The findings provide insight into how peripheral nerves function and may ultimately lead to new treatments for some peripheral neuropathies," said Alan E. Guttmacher, M.D., acting director of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), the NIH Institute that collaborated in the study.
Related chapters from BP6e: 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: 13867 - Posted: 03.15.2010
Scientists believe they have made a breakthrough in the treatment of a severe muscle disease that causes floppy baby syndrome. Most babies born with the rare disorder are severely paralysed and the majority die before the age of one. The Australian team was able to cure affected mice by replacing a missing muscle protein. A UK expert said the findings, in the Journal of Cell Biology, could lead to improved movement for affected babies. The team focussed on proteins called actins. A gene called ACTA1 controls the production of actin in skeletal muscles. It is key to allowing muscles to contract, but children with this disease have flawed versions of the gene and so the protein is not produced. However, the scientists had seen that some children with floppy baby syndrome were not totally paralysed at birth. When these children were studied, it was found that heart actin - another form of the protein - was "switched on" in their skeletal muscles, when that would not normally be the case. Heart actin is found in skeletal muscles while the baby is developing in the womb, but has almost completely disappeared by birth. The researchers found it was possible to cure mice genetically engineered to have the recessive form of the muscle disorder by replacing the missing skeletal muscle actin with heart actin. Dr Kristen Nowak, of the Western Australian Institute for Medical Research, who led the study, said: "The mice with floppy baby syndrome were only expected to live for about nine days, but we managed to cure them so they were born with normal muscle function, allowing them to live naturally and very actively into old age. This is an important step towards one day hopefully being able to better the lives of human patients - mice who were cured of the disease lived more than two years, which is very old age for a mouse." (C)BBC
The race to create more human-like robots stepped up a gear this week as scientists in Spain set about building an artificial cerebellum. The end-game of the two-year project is to implant the man-made cerebellum in a robot to make movements and interaction with humans more natural. The cerebellum is the part of the brain that controls motor functions. Researchers hope that the work might also yield clues to treat cognitive diseases such as Parkinson's. The research, being undertaken at the Department of Architecture and Computing Technology at the University of Granada, is part of a wider European project dubbed Sensopac Sensopac brings together electronic engineers, physicists and neuroscientists from a range of universities including Edinburgh, Israel and Paris with groups such as the German Aerospace Centre. It has 6.5m euros of funding from the European Commission. Its target is to incorporate the cerebellum into a robot designed by the German Aerospace Centre in two year's time. The work at the University of Granada is concentrating on the design of microchips that incorporate a full neuronal system, emulating the way the cerebellum interacts with the human nervous system. Implanting the man-made cerebellum in a robot would allow it to manipulate and interact with other objects with far greater subtlety than industrial robots can currently manage, said researcher Professor Eduardo Ros Vidal, who is co-ordinating work at the University of Granada. (C)BBC
Walking while holding a conversation and writing a letter whilst thinking about its content: we perform many actions without even thinking about them. This is possible due to the cerebellum. It regulates the automation of our movements and as a result the cerebrum can perform other tasks. However, how the cerebellum performs this task is not clear. Dutch researcher Angelique Pijpers reconstructed a part of cerebellar functioning in rats and investigated how it mediates in the control of hind limb muscles. Such research might in future provide a better understanding of how the elderly move. Pijpers and her colleagues investigated which processes took place inside and outside of the cerebellum: how does it channel information and process this into a signal to the muscles? Subsequently they investigated which parts of the cerebellum are involved in regulating the activity of a single muscle. Furthermore, they examined the consequences of inactivation of one or more parts of the cerebellum on the functioning of this muscle. Nerve cells in the cerebellum receive two types of signals. Through the climbing fibres, signals from a specific structure in the brain stem are transmitted to Purkinje cells located in the cerebellar cortex. Mossy fibres transmit signals from various parts of the central nervous system to the granule cells of the cerebellar cortex. Pijpers reconstructed the modular anatomy of the cerebellum by injecting small quantities of traceable substances. This allowed mapping of different 'stations' of the information pathway.
By Michael Purdy -- An epilepsy drug that has been on the market for decades can ease the symptoms of adult sufferers with a genetic disorder that seriously weakens muscles. Scientists at Washington University School of Medicine in St. Louis retrospectively reviewed results from off-label use of the drug valproate to treat seven adult spinal muscular atrophy (SMA) patients. Clinicians offered the drug to patients on the basis of research conducted elsewhere that showed the drug increased levels of a key protein in cell cultures. "The treatment has been fairly successful," says lead author Chris Weihl, M.D., Ph.D., a postdoctoral fellow in neurology. "The drug appeared to be well-tolerated and increased the strength of the patients who took it." The study, now available online, will appear in the August 8 issue of Neurology. Weihl notes that a larger, prospective trial is needed to firmly establish valproate as a treatment of choice for sufferers of this type of SMA. Such trials are already underway elsewhere in pediatric patients who suffer from a different type of SMA that begins earlier in life. Weihl and his colleagues are concerned that valproate may not work as well in those patients. They wanted to make sure that researchers did not discard the possibility that valproate could help older sufferers even if the trials in pediatric patients went poorly.
Researchers at the University of Minnesota Medical School have discovered the gene responsible for a type of ataxia, spinocerebellar ataxia type 5 (SCA5), an incurable degenerative brain disease affecting movement and coordination. This is the first neurodegenerative disease shown to be caused by mutations in the protein â-III spectrin which plays an important role in the maintaining the health of nerve cells. The scientific discovery has historical implications as well--the gene was identified in an 11-generation family descended from the grandparents of President Abraham Lincoln, with the President having a 25 percent risk of inheriting the mutation. "We are excited about this discovery because it provides a genetic test that will lead to improved patient diagnoses and gives us new insight into the causes of ataxia and other neurodegenerative diseases, an important step towards developing an effective treatment," said Laura Ranum, Ph.D., senior investigator of the study and professor of Genetics, Cell Biology and Development at the University of Minnesota. Understanding the effects of this abnormal protein, which provides internal structure to cells, will clarify how nerve cells die and may provide insight into other diseases, including amyotrophic lateral sclerosis (Lou Gehrig's disease) and Duchenne muscular dystrophy. The research will be published in the February print issue of Nature Genetics, and posted online Jan. 22, 2006.
A Devon scientist is developing a test to diagnose and monitor brain disorders in children using eye movements. Professor Chris Harris, from the University of Plymouth, has been seeing youngsters with some of the country's rarest diseases. Damage in various parts of the brain often leads to eye movement disorders. He hopes to develop a standard test so that babies and the most seriously ill children - who are often the most uncooperative - can be diagnosed. The earlier some conditions are treated, especially those with diseases that are only going to get worse, the better the possible outcome for the children involved. A test would also mean new types of medication can be monitored for clinical trials. Prof Harris' research has been funded by a charity called Cerebra, for brain-injured children. He is particularly interested in diagnosing so-called neurometabolic diseases, which are very difficult to diagnose. They are a group of 1,500 often terminal diseases that can be caused by chemical imbalances in the body which ultimately cause brain cells to die. He uses a computer-controlled chair with electrodes attached to the patient's head to see how "flicks" of the eye are affected by various medical conditions. He said: "The way we control our eye movements depends on brain function. Damage in various parts of the brain often leads to eye movement disorders. So by looking at abnormal eye movements we can pick up on problems before they become too severe. (C)BBC
Related chapters from BP6e: 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: 8199 - Posted: 11.21.2005
By JANE E. BRODY Paula Schneider was 38 when she developed what doctors first thought was carpal tunnel syndrome. But soon the trouble she had moving her right arm spread to her neck and back and then the whole body. She lost control of her limbs, head and torso, leaving her unable to walk, sit, eat or do much of anything. It was as if her entire body had been inhabited by jitterbugs that determined her every move. More Personal Health Columns "I couldn't eat like a normal person, brush my teeth or drink from a glass because it would break when I tried to put it down," Ms. Schneider recalled recently at a demonstration on movement disorders at Beth Israel Hospital in New York. The cause, she eventually learned, was a severe movement disorder called generalized dystonia. Various medications helped for a while. So did multiple localized injections of Botox to disrupt the flow of nerve impulses to muscles that were spastic or excessively contracted. But the benefits were limited and short-lived. She said she spent 12 years in excruciating pain. Copyright 2005 The New York Times Company
A brain area presumed to be involved only in co-ordinating movement also controls higher functions, such as vision, mounting evidence suggests. Traditionally, higher mental processing has been seen as the cerebrum's job - the evolutionary newest and largest part of the brain. The cerebellum or "little brain", which sits below the cerebrum, was thought to control balance and movement. A study of brain-injured infants shows this view is too simplistic. The research in Pediatrics looked at 74 babies born prematurely who had varying degrees of brain damage. The Harvard team from the Children's Hospital in Boston used magnetic resonance imaging (MRI) brain scans to look at the injuries in detail. When there was injury to the cerebrum, the cerebellum also failed to grow to a normal size. When the cerebral injury was confined to one side, it was the opposite half of the cerebellum that failed to grow normally. Similarly, when injury occurred in one cerebellar hemisphere, the opposite side of the cerebrum was smaller than normal, which the researchers said suggested there was an important developmental link between the two parts of the brain. Other work by Dr Catherine Limperopoulos and her colleagues suggests in addition to motor problems, children born with cerebellar injuries have problems with higher cognitive processes such as communication, social behaviour and visual perception. (C)BBC
Related chapters from BP6e: Chapter 2: Functional Neuroanatomy: The Nervous System and Behavior; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 2: Cells and Structures: The Anatomy of the Nervous System; Chapter 5: The Sensorimotor System
Link ID: 8016 - Posted: 10.10.2005
(Embargoed) CHAPEL HILL -- Scientists at the University of North Carolina at Chapel Hill may have identified the genetic basis underlying essential tremor disease, the most common human movement disorder. The discovery comes from studies involving a strain of genetically altered mice that show the same types of tremor and similar lack of coordination as people affected by essential tremor. This animal model of the disease might prove useful for screening potential treatments, said Dr. A. Leslie Morrow, associate director of UNC's Bowles Center for Alcohol Studies and professor of psychiatry and pharmacology in UNC's School of Medicine. "We believe that these mice could explain one etiology, or origin, of essential tremor disease in humans because of the marked similarities between the mouse model and the human disease," said Morrow, who led the study team. A report of the findings will appear in the March issue of the Journal of Clinical Investigation. An estimated 5 million Americans are affected by essential tremor, a neurological disease characterized by an uncontrollable shaking of the limbs, in particular the arms and head. Unlike resting tremor associated with Parkinson's disease, symptoms of essential tremor are noticeable during movement, such as lifting a cup of coffee.
By SANDRA BLAKESLEE Cheryl Schiltz vividly recalls the morning she became a wobbler. Seven years ago, recovering from an infection after surgery with the aid of a common antibiotic, she climbed out of bed feeling pretty good. "Then I literally fell to the floor," she said recently. "The whole world started wobbling. When I turned my head, the room tilted. My vision blurred. Even the air felt heavy." The antibiotic, Ms. Schiltz learned, had damaged her vestibular system, the part of the brain that provides visual and gravitational stability. She was forced to quit her job and stay home, clinging to the walls to keep from toppling over. But three years ago, Ms. Schiltz volunteered for an experimental treatment - a fat strip of tape, placed on her tongue, with an array of 144 microelectrodes about the size of a postage stamp. The strip was wired to a kind of carpenter's level, which was mounted on a hard hat that she placed on her head. The level determined her spatial coordinates and sent the information as tiny pulses to her tongue. The apparatus, called a BrainPort, worked beautifully. By "buzzing" her tongue once a day for 20 minutes, keeping the pulses centered, she regained normal vestibular function and was able to balance. Ms. Schiltz and other patients like her are the beneficiaries of an astonishing new technology that allows one set of sensory information to substitute for another in the brain. Copyright 2004 The New York Times Company
Related chapters from BP6e: 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: 6466 - Posted: 11.23.2004
Method may help halt A-T, cancer, other genetic diseases UCLA scientists have devised a novel way to repair one of the genetic mutations that cause ataxia-telangiectasia, (A-T), a life-shortening disorder that devastates the neurological and immune systems of one in 40,000 young children. Reported Oct. 18 in the Proceedings of the National Academy of Sciences, the findings could hold far-reaching implications for treating A-T, cancer and other genetic diseases. Often misdiagnosed as cerebral palsy, A-T usually strikes children before age 2 and confines them to a wheelchair by age 10. Many lose their ability to speak and die in childhood. One in three children also develop lymphoma or leukemia. Adults who carry the mutated A-T gene (ATM), including up to 15 percent of breast-cancer patients, are eight times more likely to develop cancer than the general population. Dr. Richard Gatti, professor of pathology and laboratory medicine, and Chih-Hung Lai, Ph.D., a postdoctoral researcher at the David Geffen School of Medicine at UCLA, created a new strategy for tricking the ATM gene into overlooking certain types of mutations called premature termination codons (PTCs). "PTCs are like irregular stop signs located in the middle of the block," explained Gatti. "They stop traffic before it reaches the intersection. We made these stop signs invisible, so traffic continues until it sees the proper stop sign at the end of the corner."
Few have heard of the degenerative, deadly disease called Ataxia-telangiectasia (A-T) but a University of Alberta researcher is hoping to provide clues to this mysterious disorder. Dr. Shelagh Campbell, from the U of A's Department of Biological Sciences, is a basic researcher who studies how normal cell cycles are regulated, by analyzing genes that are responsible for repairing DNA damage that offer insights into human diseases like cancer and A-T. A-T is a progressive, degenerative disease that affects a startling number of body systems. Children with A-T appear normal at birth but at around the age of two, some of the first signs--walking and balance is wobbly caused by ataxia or lack of muscle control--start appearing. "Kids are often misdiagnosed with cerebral palsy but what distinguishes A-T is it gets worse," said Campbell. "Sadly, many of the people with A-T end up in wheelchairs and most die young (I think there is a fair range).
A new genetic model for a motor disorder that confines an estimated 10,000 people in the United States to walkers and wheelchairs indicates that instability in the microscopic scaffolding within a key set of nerve cells is the cause of this devastating disability. The study, which is published in the July 13 issue of the journal Current Biology, provides a provocative new insight into the molecular basis of the disease called hereditary spastic paraplegia (HSP) and suggests a new way to treat the inherited genetic disorder. HSP--also known as familial spastic paraparesis and Strumpell-Lorrain syndrome--causes the ends of the nerves that control muscle activity to deteriorate. These nerve cells run from the brain's cerebral cortex to the spinal cord where they connect to "downstream" nerve cells that excite muscles throughout the body to control coordinated movement. HSP causes weakness, spasms and loss of function in the muscles in the lower extremities. More than 20 genes have been linked to HSP. However, more than 40 percent of all cases have been traced to a single gene (SPG4) that produces an enzyme called spastin. Previous studies have shown that this enzyme interacts with microtubules, the tiny protein tubes that provide structural support and transport avenues within most cells. Microtubules are dynamic structures, continually growing and shrinking, and their stability is closely regulated by a number of associated proteins. In nerve cells, microtubules carry cellular components to distant regions of the cell, regulate the growth of cellular branches and provide a substrate for important protein interactions. All of these functions are critically dependent on dynamic changes in microtubule stability.
By Pat Hagan Hearing a skilled musician play a piece note-perfect is one of the joys of life. But do some professional musicians pay a terrible price for their talent? A team of British researchers has recently embarked on a study that they hope will shed light on a mysterious condition that can affect the brains of up to one in ten musical artists. Aided by a grant of over £92,000 from the charity Action Medical Research, experts from the Institute of Neurology and the National Hospital for Neurology and Neurosurgery in London hope to come up with a treatment for a condition called occupational dystonia - which leaves many experienced players with involuntary muscle spasms of the hand. The disorder can affect people in many occupations that involve high levels of skill in performing certain types of movement. But it appears to be particularly striking in musicians and for some, the consequences for their performing career can be catastrophic. Experts believe the root cause of occupational dystonia is that the brain somehow becomes "overspecialised" in carrying out very specific movements. In short, part of the brain becomes permanently "rewired" so that it is highly adept at the skills it has been using for years but unable to learn new, more flexible movements. (C)BBC
MADISON - With a slight tweak of temperature, geneticist Barry Ganetzky's flies drop like, well, flies. For 25 years, Ganetzky has been identifying, breeding and studying a raft of fly mutants that, when exposed to minor temperature change, become completely paralyzed. The flies, which quickly recover when returned to room temperature, are now finding many uses in studies of human neurological disorders, drug discovery and insecticide development. Ganetzky, a University of Wisconsin-Madison professor of genetics, and his colleagues have become the undisputed champions of finding such mutants, raising the tally to upward of 100 such strains over the years.
ST. PAUL, MN ? A 33-year study of all births by women in Norway with Myasthenia Gravis (MG) confirms that MG is associated with an increased risk for complications during pregnancy, including a threefold higher incidence of preterm rupture of the amniotic membranes, and twice the occurrence of delivery by cesarean section. The study is reported in the November 25 issue of Neurology, the scientific journal of the American Academy of Neurology. Data for the study was collected from the Medical Birth Registry of Norway, based on compulsory notification of all births in the country. The study included 127 births by women with MG and the 1.9 million births by women without MG. Women with MG had twice the rate of cesarean section (17.3 percent) when compared to the control group (8.6 percent). Preterm rupture of amniotic membranes occurred three times more often ? or 5.5 percent ? compared to 1.7 percent of the general population.
Related chapters from BP6e: 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: 4594 - Posted: 11.25.2003
By HARRIET McBRYDE JOHNSON My father died when I was 2, and I lost my mother when I was 5.'' Throughout my childhood, that's what Grandmother says. She's a fine storyteller with rare gifts for gross delicacy and folksy pomposity, but she doesn't give the details, and we don't ask. To me, it's enough knowing that she's an orphan, like Heidi -- like Tarzan even! What else is worth knowing? Eventually our cousins tell us. When Grandmother was 5, her mother didn't die. She was placed in an asylum. There she lived until Grandmother was in her 20's. There she died. The news seems to answer some questions about Grandmother. Why does an independent thinker set such store on conventional behavior? Why did she marry a ridiculously steady Presbyterian? Copyright 2003 The New York Times Company
Related chapters from BP6e: Chapter 1: Biological Psychology: Scope and Outlook; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 1: An Introduction to Brain and Behavior; Chapter 5: The Sensorimotor System
Link ID: 4584 - Posted: 11.23.2003