Chapter 11. Motor Control and Plasticity
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By Karen Weintraub Essential tremor is involuntary shaking – usually of the hands, but sometimes also of the neck, jaw, voice or legs. “Any fine tasks with the hands can be very difficult when the tremor is pronounced,” said Dr. Albert Hung, center director of the Massachusetts General Hospital National Parkinson Foundation Center of Excellence. Essential tremor can affect balance, walking, hearing and cognition, and can get worse over time, said Dr. Elan Louis, chief of the division of movement disorders at Yale School of Medicine. People with essential tremor run almost twice the risk of developing Alzheimer’s as the general population. Essential tremor appears with movement; if people let their hands sit still, they don’t tremble. That is the big difference between an essential tremor and the tremor of Parkinson’s disease, which can occur while at rest, Dr. Louis said. Essential tremor also tends to strike both hands while Parkinson’s is more one-sided at first, said Dr. Hung. The cause of essential tremor remains a mystery, though it seems to run in families. People of any age or sex can have the condition, though it is more common as people grow older. Roughly 4 percent of 40-year-olds have essential tremor, compared with about 20 percent of 90-year-olds, Dr. Louis said. Available treatments “aren’t great,” Dr. Louis said. Two medications – the beta blocker propranolol and the epilepsy drug primidone, sold under the brand name Mysoline – can reduce tremors by 10 to 30 percent, he said, but they work only in about half of patients. Deep brain stimulation – implanting electrodes into the brain to override faulty electrical signals – has been shown to markedly reduce hand tremor severity, he said. But the treatment can worsen cognitive and balance problems and “doesn’t cure the underlying disease. It merely and temporarily lessons a single symptom, which is the tremor.” © 2015 The New York Times Company
Keyword: Movement Disorders
Link ID: 21653 - Posted: 11.24.2015
By Gretchen Reynolds Sturdy legs could mean healthy brains, according to a new study of British twins. As I frequently have written in this column, exercise may cause robust improvements in brain health and slow age-related declines in memory and thinking. Study after study has shown correlations between physical activity, muscular health and mental acuity, even among people who are quite old. But these studies have limitations and one of them is that some people may be luckier than others. They may have been born to have a more robust brain than someone else. Their genes and early home environment might have influenced their brain health as much as or more than their exercise habits. Their genes and early home environment also might have influenced those exercise habits, as well as how their bodies and brains responded to exercise. In other words, genes and environment can seriously confound experimental results. That problem makes twins so valuable for scientific purposes. (Full disclosure, I am a twin, although not an identical one.) Twins typically share the same early home environment and many of the same genes, and if they are identical, all their genes are the same. So if one twin’s body, brain and thinking abilities begin to differ substantially over the years from their twin’s, the cause is less likely to be solely genetic or the early environment, and more likely to be attributable to lifestyle, including exercise habits. It was that possibility that recently prompted Claire Steves, a senior lecturer in twin research at King’s College London, to consider twins and their thighs. © 2015 The New York Times Company
Link ID: 21641 - Posted: 11.18.2015
Ewen Callaway Ringo, a golden retriever born in 2003 in a Brazilian kennel, was never expected to live long. Researchers bred him and his littermates to inherit a gene mutation that causes severe muscular dystrophy. They hoped that the puppies would provide insight into Duchenne muscular dystrophy (DMD), an untreatable and ultimately fatal human disease caused by inactivation of the same gene. But Ringo’s muscles didn't waste away like his littermates', and researchers have now determined why: he was born with another mutation that seems to have protected him from the disease, according to a paper published in Cell1. Scientists hope that by studying Ringo’s mutation — which has never before been linked to muscular dystrophy — they can find new treatments for the disease. As many as 1 in 3,500 boys inherit mutations that produce a broken version of a protein called dystrophin, causing DMD. (The disease appears in boys because the dystrophin gene sits on the X chromosome, so girls must inherit two copies of the mutated gene to develop DMD.) The protein helps to hold muscle fibres together, and its absence disrupts the regenerative cycle that rebuilds muscle tissue. Eventually, fat and connective tissue replace muscle, and people with DMD often become reliant on a wheelchair before their teens. Few survive past their thirties. Some golden retriever females carry dystrophin mutations that cause a similar disease when passed onto male puppies. Dog breeders can prevent this through genetic screening. But Mayana Zatz, a geneticist at the University of São Paulo in Brazil, and her colleagues set out to breed puppies with the mutation to model the human disease. © 2015 Nature Publishing Group,
By Emily Underwood Researchers have found a way to increase how fast, and for how long, four paralyzed people can type using just their thoughts. The advance has to do with brain-machine interfaces (BCI), which are implanted in brain tissue and record hundreds of neurons firing as people imagine moving a computer cursor. The devices then use a computer algorithm to decode those signals and direct a real cursor toward words and letters on a computer screen. One of the biggest problems with BCIs is the brain itself: When the soft, squishy organ shifts in the skull, as it frequently does, it can displace the electrode implants. As a result, the movement signal extracted from neuronal firing is constantly being distorted, making it impossible for a patient to keep the cursor from drifting off course without a researcher recalibrating the instrument every 10 minutes or so. In the new study, part of a clinical trial of BCIs called BrainGate, researchers performed several software tweaks that allow the devices to self-correct in real time by calculating the writer’s intention based on the words they’ve already written. The devices can now also correct for neuronal background noise whenever a person stops typing. These improvements, demonstrated in the video above, allow BCI users to type faster and for longer periods of time, up to hours or days, the team reports today in Science Translational Medicine. Though the technology still needs to be miniaturized and wireless before it can be used outside of the lab, the new work is a big step towards BCIs that paralyzed people can use on their own at home, the scientists say. © 2015 American Association for the Advancement of Science
Link ID: 21626 - Posted: 11.12.2015
By Diana Kwon Six years before her husband was diagnosed with Parkinson’s disease, a progressive neurodegenerative disorder marked by tremors and movement difficulties, Joy Milne detected a change in his scent. She later linked the subtle, musky odor to the disease when she joined the charity Parkinson’s UK and met others with the same, distinct smell. Being one of the most common age-related disorders, Parkinson’s affects an estimated seven million to 10 million people worldwide. Although there is currently no definitive diagnostic test, researchers hope that this newly found olfactory signature will lead help create one. Milne, a super-smeller from Perth, Scotland, wanted to share her ability with researchers. So when Tilo Kunath, a neuroscientist at the University of Edinburgh, gave a talk during a Parkinson’s UK event in 2012, she raised her hand during the Q&A session and claimed she was able to smell the disease. “I didn’t take her seriously at first,” Kunath says. “I said, ‘No, I never heard of that, next question please.’” But months later Kunath shared this anecdote with a colleague and received a surprising response. “She told me that that lady wasn’t wrong and that I should find her,” Kunath says. Once the researchers found Milne, they tested her claim by having her sniff 12 T-shirts: six that belonged to people with Parkinson’s and six from healthy individuals. Milne correctly identified 11 out of 12, but miscategorized one of the non-Parkinson’s T-shirts in the disease category. It turned out, however, she was not wrong at all—that person would be diagnosed with Parkinson’s less than a year later. © 2015 Scientific American
By Diana Kwon | In the human form of mad cow disease, called Creutzfeldt-Jakob, a person's brain deteriorates—literally developing holes that cause rapidly progressing dementia. The condition is fatal within one year in 90 percent of cases. The culprits behind the disease are prions—misfolded proteins that can induce normal proteins around them to also misfold and accumulate. Scientists have known that these self-propagating, pathological proteins cause some rare brain disorders, such as kuru in Papua New Guinea. But growing evidence suggests that prions are at play in many, if not all, neurodegenerative disorders, including Alzheimer's, Huntington's and Parkinson's, also marked by aggregations of malformed proteins. Until recently, there was no evidence that the abnormal proteins found in people who suffer from these well-known diseases could be transmitted directly from person to person. The tenor of that discussion suddenly changed this September when newly published research in the journal Nature provided the first hint such human-to-human transmission may be possible. (Scientific American is part of Springer Nature.) For the study, John Collinge, a neurologist at University College London, and his colleagues conducted autopsies on eight patients who died between the ages of 36 and 51 from Creutzfeldt-Jakob. All the subjects had acquired the disease after treatment with growth hormone later found to be contaminated with prions. The surprise came when the researchers discovered that six of the brains also bore telltale signs of Alzheimer's—in the form of clumps of beta-amyloid proteins, diagnostic for the disease—even though the patients should have been too young to exhibit such symptoms. © 2015 Scientific American,
By Hanae Armitage CHICAGO, ILLINOIS—Huntingtons disease, a neurological condition caused by brain-destroying mutant proteins, starts with mood swings and twitching and ends in dementia and death. The condition, which afflicts about 30,000 Americans, has no cure. But now, a new gene-editing method that many believe will lead to a Nobel Prize has been shown to effectively halt production of the defective proteins in mice, leading to hope that a potent therapy for Huntingtons is on the distant horizon. That new method is CRISPR, which uses RNA-guided enzymes to snip out or add segments of DNA to a cell. In the first time it has been applied to Huntingtons disease, CRISPR’s results are “remarkably encouraging,” says neuroscientist Nicole Déglon of the University of Lausanne in Switzerland, who led the mouse study, results of which she and her co-researcher Nicolas Merienne shared yesterday at the Society for Neuroscience Conference in Chicago, Illinois. As neurological diseases go, Huntingtons is an ideal candidate for CRISPR therapy, because the disease is determined by a single gene, Déglon notes. A mutation in the gene, which codes for a normally helpful brain protein called huntingtin, consists of different numbers of “tandem repeats,” repeating segments of DNA that cause the protein to fold into a shape that is toxic to the brain. Déglon and her team wondered whether CRISPR could halt production of this dangerous molecule. Using a virus as a delivery vehicle, the researchers infected two separate groups of healthy adult mice with a mutant huntingtin gene, but only one group received the therapy: a CRISPR “cassette,” which includes DNA for the gene-editing enzyme Cas9 and the RNA to target the huntingtin gene. © 2015 American Association for the Advancement of Science
Link ID: 21538 - Posted: 10.21.2015
Alan Hoffman says nilotinib has changed his life. Just weeks after he started taking the drug in a clinical trial, he began to feel himself recovering from his Parkinson’s disease. The retired professor of social science first started to show the signs of Parkinson’s in 1997. Over the years, his symptoms worsened. “I couldn’t get out of bed without my wife,” Hoffman says. Once a prolific reader, devouring four or five books a week, Hoffman found himself unable to keep his attention on even a short magazine article. His body became increasingly rigid, and he started to lose his sense of balance. “I fell a lot,” he says. And it affected his social life. The disorder was such a struggle, Hoffman says he considered taking his own life. He tried a range of medications, which eased his symptoms to varying degrees. In 2008, he had surgery to implant an electrode into his brain. The deep brain stimulation that followed helped with the rigidity, he says. But deep brain stimulation doesn’t offer a cure – the brain cells continue to die. So Hoffman agreed to join a six-month clinical trial of nilotinib – a drug typically used to treat leukaemia. Nilotinib blocks a protein that interferes with lysosomes – cell structures that destroy harmful proteins. Researchers behind the trial think that nilotinib can free up lysosomes to do a better job of clearing out proteins associated with Parkinson’s disease. (For a full report on the effect of the drug see “People with Parkinson’s walk again after promising drug trial”.) © Copyright Reed Business Information Ltd.
Link ID: 21537 - Posted: 10.21.2015
An expensive cancer drug may reverse late-stage Parkinson’s disease, enabling participants in a small clinical trial to speak and walk again for the first time in years. While there are several treatments for the symptoms of Parkinson’s, if confirmed this would be the first time a drug has worked on the causes of the disease. “We’ve seen patients at end stages of the disease coming back to life,” says Charbel Moussa of Georgetown University Medical Center in Washington DC, who led the trial. The drug, called nilotinib, works by boosting the brain’s own “garbage disposal system” to clear proteins that accumulate in the brains of people with Parkinson’s disease, says Moussa. These proteins are thought to trigger the death of brain cells that make molecules like dopamine that are needed for movement and other functions. Nilotinib is already approved to treat cancer – it blocks a protein that drives chronic myeloid leukaemia. It also blocks another protein that interferes with lysosomes – cell structures that destroy harmful proteins. Moussa thinks that nilotinib can free up lysosomes to do a better job of clearing out proteins associated with Parkinson’s disease. Tests in animals showed promise, so Moussa, his colleague Fernando Pagan and their team set up a small trial of 12 volunteers with Parkinson’s disease or a similar condition called dementia with Lewy bodies. The trial was designed to test only the safety of the oral drug, which was given as a daily dose for six months. © Copyright Reed Business Information Ltd.
Link ID: 21528 - Posted: 10.20.2015
Three teams of scientists supported by the National Institutes of Health showed that a genetic mutation linked to some forms of amyotrophic lateral sclerosis (ALS) and frontotemporal degeneration (FTD) may destroy neurons by disrupting the movement of materials in and out of the cell’s nucleus, or command center where most of its DNA is stored. The results, published in the journals Nature and NatureNeuroscience, provide a possible strategy for treating the two diseases. “This research shines a spotlight on the role of nuclear transport in the health of neurons,” said Amelie Gubitz, Ph.D., program director at the NIH’s National Institute of Neurological Disorders and Stroke (NINDS). “The results provide new insights into how this mutation derails an essential process in neurons and opens new avenues for therapy development.” Both ALS and FTD are caused by the death of specific neurons. In ALS, this leads to movement difficulties and eventually paralysis, while in FTD, patients experience problems with language and decision making. Past research has connected a specific mutation in the C9orf72 gene to 40 percent of inherited ALS cases and 25 percent of inherited FTD cases, as well as nearly 10 percent of non-inherited cases of each disorder. The recent experiments, conducted in yeast, fruit flies, and neurons from patients, found that the mutation prevents proteins and genetic material called RNA from moving between the nucleus and the cytoplasm that surrounds it. “At the end of the day, this culminates in a defect in the flow of genetic information, which leads to problems expressing genes in the right place at the right time,” said J. Paul Taylor, M.D., Ph.D., a researcher at St. Jude’s Children’s Research Hospital in Memphis, Tennessee, and the senior author of one of the papers.
Keyword: ALS-Lou Gehrig's Disease
Link ID: 21524 - Posted: 10.17.2015
By Gretchen Reynolds Can a shot of salt water make you a faster runner? The answer appears to be a resounding yes, if you believe that the salt water contains something that should make you a faster runner, according to a new study of the power of placebos in athletic performance. Anyone who exercises knows from experience that our minds and mental attitudes affect physical performance. Who hasn’t faced a moment when, tiring at the end of a strenuous workout or race, we are about to quit before suddenly being passed on the path or shown up in the gym by someone we know we should outperform, and somehow we find an extra, unexploited gear and spurt on? This phenomenon is familiar to physiologists, many of whom believe that our brains, in order to protect our bodies, send out signals telling those bodies to quit before every single resource in our muscles and other tissues is exhausted. We think we are at the outer limits of our endurance or strength, when, in reality, we may still have a physical reserve available to us, if we can find a way to tap it. Past studies have shown that lying to people is one way to exploit that reserve. Telling athletes that they are moving slower than in fact they are, for instance, often results in their speeding up past the pace that they thought they could maintain. Or give them a sugar pill that they think contains caffeine or steroids and they will run more swiftly or lift more weight than before. But none of these studies tested the effects of placebos and deception in relatively real-world competitive situations, which have their own effects on mental responses. People are almost always faster during competitive races than in training, studies show, even when they are trying to replicate race pace. © 2015 The New York Times Company
Keyword: Pain & Touch
Link ID: 21509 - Posted: 10.14.2015
Laura Sanders Scribes usually have pretty good handwriting. That’s not the case for one prolific 13th century writer known to scholars only as the Tremulous Hand of Worcester. Now scientists suggest the writer suffered from a neurological condition called essential tremor. Neurologist Jane Alty and historical handwriting researcher Deborah Thorpe, both of the University of York in England, made the retrospective diagnosis August 31 in Brain after studying the spidery wiggles that pervade the scribe’s writing. Essential tremor can cause shaking of the hands, head and voice and is distinct from other tremor-causing conditions such as Parkinson’s disease. Here, the anonymous writer’s peculiar script is evident (lighter portion of text) in an early Middle English version of the Nicene Creed, a summary of the Christian faith. Buried in the manuscript are clues that helped the researchers conclude that essential tremor plagued the Tremulous Hand. The Tremulous Hand of Worcester’s writing appeared in more than 20 books, including the Nicene Creed, a summary of the Christian faith. The writer’s distinctive script is the lighter portion of the text, about a third of the way down the page. Several clues led researchers to diagnose the scribe with essential tremor (see following images). © Society for Science & the Public 2000 - 2015.
Keyword: Movement Disorders
Link ID: 21482 - Posted: 10.07.2015
By Jon Cohen A virus that long ago spliced itself into the human genome may play a role in amyotrophic lateral sclerosis (ALS), the deadly muscle degenerative disease that crippled baseball great Lou Gehrig and ultimately took his life. That’s the controversial conclusion of a new study, which finds elevated levels of human endogenous retrovirus K (HERV-K) in the brains of 11 people who died from the disease. “This certainly is interesting and provocative work,” says Raymond Roos, a neurologist at the University of Chicago in Illinois who treats and studies ALS but who was not involved with the finding. Still, even the scientists behind the work caution that more research is needed to confirm the link. “I’m very careful to say HERV-K doesn’t cause the disease but may play a role in the pathophysiology,” says study leader Avindra Nath, a neuroimmunologist at the National Institute of Neurological Disorders and Stroke in Bethesda, Maryland. “The darn thing is in the chromosomes to begin with. It’s going to be very hard to prove causation.” It was another retrovirus, HIV, that led Nath to first suspect a connection between viruses and ALS. In 2006, he was helping a patient control his HIV infection with antiretroviral drugs when he noticed that the man’s ALS also improved. “That intrigued me, and I looked in the ALS literature and saw that people had reported they could see reverse transcriptase in the blood.” Reverse transcriptase, an enzyme that converts RNA to DNA, is a hallmark of retroviruses, which use it to insert copies of their genes into chromosomes of their hosts. © 2015 American Association for the Advancement of Science
James Hamblin Mental exercises to build (or rebuild) attention span have shown promise recently as adjuncts or alternatives to amphetamines in addressing symptoms common to Attention Deficit Hyperactivity Disorder (ADHD). Building cognitive control, to be better able to focus on just one thing, or single-task, might involve regular practice with a specialized video game that reinforces "top-down" cognitive modulation, as was the case in a popular paper in Nature last year. Cool but still notional. More insipid but also more clearly critical to addressing what's being called the ADHD epidemic is plain old physical activity. This morning the medical journal Pediatrics published research that found kids who took part in a regular physical activity program showed important enhancement of cognitive performance and brain function. The findings, according to University of Illinois professor Charles Hillman and colleagues, "demonstrate a causal effect of a physical program on executive control, and provide support for physical activity for improving childhood cognition and brain health." If it seems odd that this is something that still needs support, that's because it is odd, yes. Physical activity is clearly a high, high-yield investment for all kids, but especially those attentive or hyperactive. This brand of research is still published and written about as though it were a novel finding, in part because exercise programs for kids remain underfunded and underprioritized in many school curricula, even though exercise is clearly integral to maximizing the utility of time spent in class.
A 26-year-old man who is paralysed in both legs has walked for the first time in five years – just by thinking about it. He is the first person to have his brain activity recorded and used to control a muscle-stimulating device in his legs. Every year, 250,000 to 500,000 people worldwide suffer spinal cord injuries, which can leave them partially or completely paralysed below the site of damage. Many rehabilitation clinics already offer functional electric stimulation (FES) devices, which activate the nerves that innervate leg muscles at the push of a button. But people with upper-body paralysis are not always able to operate the FES in this way. The new system bypasses the button and returns control to the brain. “We want to re-establish the connection between the brain and the leg muscles, to bring back the function that was once present,” says Zoran Nenadic at the University of California Irvine. To do that, Nenadic and his colleagues combined an FES system with a brain-computer interface. The team developed an electrode cap that picks up the brainwaves created when a person thinks specifically about walking or standing still. They tailored the device to pick up brain signals from their volunteer – a man who has had little sensation below his shoulder blades for five years. © Copyright Reed Business Information Ltd.
Link ID: 21437 - Posted: 09.24.2015
By Kristin Ozelli Four years ago writer and producer Jon Palfreman was diagnosed with Parkinson’s disease. He has chronicled his experience and that of many other “Parkies,” as patients sometimes call themselves, in two books, the latest of which is Brain Storms: The Race to Unlock the Mysteries of Parkinson’s Disease, published this year by Scientific American / Farrar, Straus and Giroux, which traces some of the recent progress of medical researchers in treating this disease. He shared with Scientific American MIND senior editor Kristin Ozelli some of the insights he gleaned while working on this book. You wrote an earlier book about Parkinson’s and produced a prize-winning documentary, The Case of the Frozen Addicts, and have experienced the disease personally. While you were researching Brain Storms, was there anything new you learned about the disease that really surprised you? What is truly surprising is just how long biomedical research takes to deliver life-changing therapies. The promising therapies around when I wrote my first book 20 years ago, like neural grafting and growth factors—therapies designed to replace, revive or protect dopamine neurons—well they haven’t panned out. On the other hand, since my first involvement with Parkinson’s, there have been some extraordinary advances in basic science. In a sense, the disease has been rebranded from a movement disorder (resulting from damage to a very small part of the brain) to a systemic condition involving not only tremor and rigidity but also a whole host of symptoms—from depression to sleep disorders, from constipation to dementia. Indeed, there’s an entirely new theory of the disease that sees it as being driven by a protein alpha-synuclein that goes rogue and, prionlike, jumps from neuron to neuron creating havoc. © 2015 Scientific American
Link ID: 21435 - Posted: 09.23.2015
Nathan Seppa For a historically mistrusted drink, coffee is proving to be a healthy addiction. Scientific findings in support of coffee’s nutritional attributes have been arriving at a steady drip since the 1980s, when Norwegian researchers reported that coffee seemed to fend off liver disease. Since then, the dark brown beverage has shown value against liver cancer, too, as well as type 2 diabetes, heart disease and stroke. Coffee even appears to protect against depression, Parkinson’s and Alzheimer’s diseases. Taken as a whole, these results might explain the most astonishing finding of all. People who drink two or more cups of coffee a day live longer than those who don’t, after accounting for behavioral differences, U.S. researchers reported in 2012. Studies in Japan, Scotland and Finland agree. Talk about a twofer. Coffee not only picks you up, it might put off the day they lower you down. Yet coffee has had trouble shaking its bad-for-you reputation. It may be one of the most widely consumed drinks in the world, but people have long assumed that, at least in its energizing caffeinated version, coffee comes with a catch. “People notice the caffeine,” says cardiologist Arthur Klatsky, who has researched coffee for decades at the Kaiser Permanente Northern California Division of Research in Oakland. “And there is this general feeling that anything that has some effect on the nervous system has to have something bad about it.” It doesn’t help that caffeine is mildly addictive.
By Larry Greenemeier Advanced prosthetics have for the past few years begun tapping into brain signals to provide amputees with impressive new levels of control. Patients think, and a limb moves. But getting a robotic arm or hand to sense what it’s touching, and send that feeling back to the brain, has been a harder task. The U.S. Defense Department’s research division last week claimed a breakthrough in this area, issuing a press release touting a 28-year-old paralyzed person’s ability to “feel” physical sensations through a prosthetic hand. Researchers have directly connected the artificial appendage to his brain, giving him the ability to even identify which mechanical finger is being gently touched, according to the Defense Advanced Research Projects Agency (DARPA). In 2013, other scientists at Case Western Reserve University also gave touch to amputees, giving patients precise-enough feeling of pressure in their fingertips to allow them to twist the stems off cherries. The government isn’t providing much detail at this time about its achievement other than to say that researchers ran wires from arrays connected to the volunteer’s sensory and motor cortices—which identify tactile sensations and control body movements, respectively—to a mechanical hand developed by the Applied Physics Laboratory (APL) at Johns Hopkins University. The APL hand’s torque sensors can convert pressure applied to any of its fingers into electrical signals routed back to the volunteer’s brain. © 2015 Scientific American
A choir of Canadians with Parkinson's disease is helping researchers test how well the performers regain facial movement to express emotions. Tremors and difficulty walking are often the most noticeable symptoms of Parkinson's disease, which affects about one in 500 people in Canada. Those with the disease may also have limited facial movement, which hampers the ability to express themselves. For people with Parkinson's who have "masked face syndrome," it can be difficult for others to decipher how they're feeling. That's because we unknowingly mimic or mirror each other during interaction to connect. "Within a hundred milliseconds of seeing someone else smile or frown, we are smiling or frowning," said Frank Russo, a psychology professor at Ryerson University in Toronto. "We're mirroring what the other person is doing. And that's one of the things that is absent in Parkinson's. It's the absence of mirroring that is leading to some of the deficit in understanding other people's emotions." Having a static face can leave people with Parkinson's seem cold and aloof as they also show deficits in understanding other people's emotions. The patient can then become emotionally disconnected from others. Studying the 28 members of the Parkinson's choir has bolstered Russo's thinking that singing, facial expressions and social communications are interconnected. So far Russo has found that mirroring effect or mimicry was restored among choir participants who sang for 13 weeks. ©2015 CBC/Radio-Canada.
Ever waited for a bus rather than take the short walk to work? Headed for the escalator instead of the stairs? Humans clearly harbour a deep love of lethargy – and now we know how far people will go to expend less energy. We will change our walking style on the fly when our normal gait becomes even a little more difficult. The finding could have implications for the rehabilitation offered to people with spinal injuries. Jessica Selinger and her colleagues at Simon Fraser University in Burnaby, British Columbia, Canada, strapped volunteers into a lightweight robotic exoskeleton and put them on a treadmill. Initially, the team let the volunteers find their preferred walking rhythm – which turned out to be 1.8 steps per second, on average. Then the researchers switched on the exoskeleton, programming it to make it more difficult for the volunteers to walk at their preferred pace by preventing the knee from bending – and leg swinging – as freely. The exoskeleton didn’t interfere with the human guinea pigs’ ability to walk faster or slower than they preferred. Within minutes the volunteers had found a walking style that the exoskeleton would allow without offering resistance. Remarkably, though, they did so despite the fact that the exoskeleton only ever offered minimal resistance. By using breathing masks to analyse the volunteers’ metabolic activity, Selinger’s team found that subjects would shift to an awkward new gait even if the energy saving was only 5 per cent. “People are able to adapt and fine-tune in order to move in the most energetically optimal way,” says Selinger. “People will change really fundamental characteristics of their gait.” © Copyright Reed Business Information Ltd.
Keyword: Movement Disorders
Link ID: 21398 - Posted: 09.11.2015