Chapter 11. Motor Control and Plasticity
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By Nicholas Bakalar Exposure to pesticides may increase the risk for amyotrophic lateral sclerosis, also known as Lou Gehrig’s disease, a new study has found. The study, in JAMA Neurology, included 156 patients with A.L.S. and 128 controls. All participants completed questionnaires providing information on age, sex, ethnicity, education, marital status, residential history, occupational history, smoking and military service. The researchers used the information on residence and occupation to estimate long-term exposure to pesticides, and then took blood samples to determine serum levels of 122 persistent environmental pollutants. The scientists divided exposure into four time periods: ever exposed, exposed in the last 10 years, exposed 10 to 30 years ago, and exposed more than 30 years ago. Exposure to pesticides at any time was associated with a fivefold increased relative risk for A.L.S. compared to no exposure. Even exposure more than 30 years ago tripled the risk. Military service was associated with double the risk, confirming findings of previous studies. “This is an association, not causality,” cautioned the senior author, Dr. Eva L. Feldman, a professor of neurology at the University of Michigan. “We found that people with A.L.S. were five times more likely to have been exposed to pesticides, but we don’t want people to conclude that pesticides cause A.L.S.” © 2016 The New York Times Company
By Dan Kiefer I’m on the heavy bag, throwing left jabs, ignoring the relentless blare of Kanye’s “Drive Slow, Homie” played at a volume that would raise the dead. I punch to a one-two count: left jab, right cross. I’m working as hard as I’ve ever worked, and even in this unheated gym I sweat as if it’s a sauna. Finally, the bell rings. It feels as if I’ve been at it for an hour; actually, three minutes have passed. The ensuing one-minute break seems to last four seconds. Let’s be clear: Boxing, even when the opponent is only a heavy bag, is a brutal sport. But brutality is needed, even welcome, when you’re facing a progressive, incurable neurological disease. I have Parkinson’s disease, and it causes my body to just freeze up. Weirdly enough, boxing helps me get unstuck. All 12 of us in this class bear the unmistakable signs of Parkinson’s disease. I spot a dapper, cheerful white-haired fellow shaking like a leaf (tremor). Next, a balding, heavyset guy stumbling forward awkwardly on his toes (dystonia, or muscle cramping). Then I see myself in a mirror: a man in a white T-shirt, khaki shorts and Nike running shoes, standing still, seemingly paralyzed. I’m in the midst of a Parkinson’s freeze (an extreme form of bradykinesia, or slow movement). Although Parkinson’s is generally thought of as an old-person’s disease, I was diagnosed with a young-onset version 18 years ago, at age 35. Since then, I’ve taken every sort of medication known to science. I’ve had brain surgery — two tiny electrodes were implanted deep in my brain to stimulate an area affected by Parkinson’s — which unquestionably have helped treat some of my symptoms. But medicine and surgery have not cured my freezing and falling, my gait and balance issues that worsen as my disease progresses: When walking across a busy street, I may suddenly, inexplicably come to a full stop as the light is about to change. Even the slightest downhill slope of a path causes me to fall forward.
Link ID: 22198 - Posted: 05.10.2016
By Jocelyn Kaiser Gene therapy is living up to its promise of halting a rare, deadly brain disease in young boys. In a new study presented in Washington, D.C., yesterday at the annual meeting of the American Society of Gene and Cell Therapy, all but one of 17 boys with adrenoleukodystrophy (ALD) remained relatively healthy for up to 2 years after having an engineered virus deliver into their cells a gene to replenish a missing protein needed by the brain. The results, which expand on an earlier pilot study, bring this ALD therapy one step closer to the clinic. About one in 21,000 boys are born with ALD, which is caused by a flaw in a gene on the X chromosome that prevents cells from making a protein that the cells need to process certain fats—females have a backup copy of the gene on their second X chromosome. Without that protein, the fats build up and gradually destroy myelin sheaths that protect nerves in the brain. In the cerebral form of ALD, which begins in childhood, patients quickly lose vision and mobility, usually dying by age 12. The disease achieved some degree of fame with the 1992 film Lorenzo’s Oil, inspired by a family’s struggle to prolong their son’s life with a homemade remedy. The only currently approved treatment for ALD is a bone marrow transplant -- white blood cells in the marrow go to the brain and turn into glial cells that produce normal ALD proteins. But bone marrow transplants carry many risks, including immune rejection, and matching donors can’t always be found. As an alternative, in the late 2000s, French researchers treated the bone cells of two boys with a modified virus carrying the ALD gene. They reported in Science in 2009 that this halted progression of the disease. © 2016 American Association for the Advancement of Science
Laura Sanders Iron, says aging expert Naftali Raz, is like the Force. It can be good or bad, depending on the context. When that context is the human brain, though, scientists wrangle over whether iron is a dark force for evil or a bright source of support. Some iron is absolutely essential for the brain. On that, scientists agree. But recent studies suggest to some researchers that too much iron, and the chemical reactions that ensue, can be dangerous or deadly, especially to nerve cells in the vulnerable brain area that deteriorates with Parkinson’s disease. Yet other work raises the possibility that those cells die because of lack of iron, rather than too much. “There are a lot of surprises in this field,” says iron biologist Nancy Andrews of Duke University. The idea that too much iron is dangerous captivates many researchers, including analytical neurochemist Dominic Hare of the University of Technology Sydney. “All of life is a chemical reaction,” he says, “so the start of disease is a chemical reaction as well.” And as Raz points out, reactions involving iron are both life-sustaining and dangerous. “Iron is absolutely necessary for conducting the very fundamental business in every cell,” says Raz, of Wayne State University in Detroit. It helps produce energy-storing ATP molecules. And that’s a dirty job, throwing off dangerous free radicals that can cause cellular mayhem as energy is made. But those free radicals are not the most worrisome aspect of iron, Hare believes. “The reaction that is much more dangerous is the reaction you get when iron and dopamine come together,” he says. © Society for Science & the Public 2000 - 2016.
Link ID: 22173 - Posted: 05.03.2016
By ANDREW POLLACK In a confrontation between the hopes of desperate patients and clinical trial data, advisers to the Food and Drug Administration voted on Monday not to recommend approval of what would become the first drug for Duchenne muscular dystrophy. The negative votes came despite impassioned pleas from patients, parents and doctors who insisted that the drug, called eteplirsen, was prolonging the ability of boys with the disease to walk well beyond when they would normally be in wheelchairs. The problem was that the drug’s manufacturer, Sarepta Therapeutics, was trying to win approval based on a study involving only 12 patients without an adequate placebo control. The advisory panel voted 7 to 3, with three abstentions, that the clinical data did not meet the F.D.A. requirements for well controlled studies necessary for approval. However, some of the panel members had trouble reconciling the often compelling patient testimony with the F.D.A. legal requirements. “I was just basically torn between my mind and my heart,” said Richard P. Hoffmann, a pharmacist who was the consumer representative on the committee and who abstained. Dr. Bruce I. Ovbiagele, chairman of neurology at the Medical University of South Carolina, voted against approval but said, “Based on all I heard, the drug definitely works, but the question was framed differently.” On another question of whether the drug could qualify for so-called accelerated approval, a lower hurdle, the panel voted 7 to 6 against the drug. The F.D.A., which does not have to follow the advice of its advisory panels, is scheduled to decide whether to approve eteplirsen by May 26. © 2016 The New York Times Company
Melissa Davey Researchers have developed the world’s first blood test that can detect the abnormal metabolism of blood cells in people with Parkinson’s disease, which means the blood test could be used to diagnose the disorder. At present the only way to diagnose Parkinson’s disease, a degenerative neurological condition, is through ordering a range of tests and scans to rule out other disorders, combined with examining symptoms. Patients are often diagnosed only after they have developed symptoms and brain cells have already been destroyed. While there is no cure for Parkinson’s, early detection allows treatment with medication and physiotherapy to begin, which may slow the deterioration of motor functions in patients. Because diagnosing the disease is a process of elimination, and the symptoms mimic those of other neurological disorders, patients are also at risk being diagnosed and treated for the wrong disease. The group of Australian researchers from La Trobe University believe their blood test will enable doctors to detect Parkinson’s disease with unprecedented reliability and lead to earlier treatment. Their findings are under review by an international medical journal. © 2016 Guardian News and Media Limited
Link ID: 22120 - Posted: 04.20.2016
By BENEDICT CAREY Five years ago, a college freshman named Ian Burkhart dived into a wave at a beach off the Outer Banks in North Carolina and, in a freakish accident, broke his neck on the sandy floor, permanently losing the feeling in his hands and legs. On Wednesday, doctors reported that Mr. Burkhart, 24, had regained control over his right hand and fingers, using technology that transmits his thoughts directly to his hand muscles and bypasses his spinal injury. The doctors’ study, published by the journal Nature, is the first account of limb reanimation, as it is known, in a person with quadriplegia. Doctors implanted a chip in Mr. Burkhart’s brain two years ago. Seated in a lab with the implant connected through a computer to a sleeve on his arm, he was able to learn by repetition and arduous practice to focus his thoughts to make his hand pour from a bottle, and to pick up a straw and stir. He was even able to play a guitar video game. “It’s crazy because I had lost sensation in my hands, and I had to watch my hand to know whether I was squeezing or extending the fingers,” Mr. Burkhart, a business student who lives in Dublin, Ohio, said in an interview. His injury had left him paralyzed from the chest down; he still has some movement in his shoulders and biceps. The new technology is not a cure for paralysis. Mr. Burkhart could use his hand only when connected to computers in the lab, and the researchers said there was much work to do before the system could provide significant mobile independence. But the field of neural engineering is advancing quickly. Using brain implants, scientists can decode brain signals and match them to specific movements. Previously, people have learned to guide a cursor on a screen with their thoughts, monkeys have learned to skillfully use a robotic arm through neural signals and scientists have taught monkeys who were partly paralyzed to use an arm with a bypass system. This new study demonstrates that the bypass approach can restore critical skills to limbs no longer directly connected to the brain. © 2016 The New York Times Company
Link ID: 22106 - Posted: 04.14.2016
For decades, it was thought that scar-forming cells called astrocytes were responsible for blocking neuronal regrowth across the level of spinal cord injury, but recent findings challenge this idea. According to a new mouse study, astrocyte scars may actually be required for repair and regrowth following spinal cord injury. The research was funded by the National Institutes of Health, and published in Nature. “At first, we were completely surprised when our early studies revealed that blocking scar formation after injury resulted in worse outcomes. Once we began looking specifically at regrowth, though, we became convinced that scars may actually be beneficial,” said Michael V. Sofroniew, M.D., Ph.D., professor of neurobiology at the University of California, Los Angeles, and senior author of the study. “Our results suggest that scars may be a bridge and not a barrier towards developing better treatments for paralyzing spinal cord injuries.” Neurons communicate with one another by sending messages down long extensions called axons. When axons in the brain or spinal cord are severed, they do not grow back automatically. For example, damaged axons in the spinal cord can result in paralysis. When an injury occurs, astrocytes become activated and go to the injury site, along with cells from the immune system and form a scar. Scars have immediate benefits by decreasing inflammation at the injury site and preventing spread of tissue damage. However, long-term effects of the scars were thought to interfere with axon regrowth.
By Esther Hsieh Spinal implants have suffered similar problems as those in the brain—they tend to abrade tissue, causing inflammation and ultimately rejection by the body. Now an interdisciplinary research collaboration based in Switzerland has made a stretchable implant that appears to solve this problem. Like Lieber's new brain implant, it matches the physical qualities of the tissue where it is embedded. The “e-dura” implant is made from a silicone rubber that has the same elasticity as dura mater, the protective skin that surrounds the spinal cord and brain, explains Stéphanie Lacour, a professor at the school of engineering at the Swiss Federal Institute of Technology in Lausanne. This feature allows the implant to mimic the movement of the surrounding tissues. Embedded in the e-dura are electrodes for stimulation and microchannels for drug therapy. Ultrathin gold wires are made with microscopic cracks that allow them to stretch. Also, the electrodes are coated with a special platinum-silicone mixture that is stretchable. In an experiment that lasted two months, the scientists found that healthy rats with an e-dura spinal implant could walk across a ladder as well as a control group with no implant. Yet rats with a traditional plastic implant (which is flexible but not stretchable) started stumbling and missing rungs a few weeks after surgery. The researchers removed the implants and found that rats with a traditional implant had flattened, damaged spinal cords—but the e-dura implants had left spinal cords intact. Cellular testing also showed a strong immune response to the traditional implant, which was minimal in rats with the e-dura implant. © 2016 Scientific American
Sara Reardon Elite ski jumpers rely on extreme balance and power to descend the steep slopes that allow them to reach up to 100 kilometres per hour. But the US Ski and Snowboard Association (USSA) is seeking to give its elite athletes an edge by training a different muscle: the mind. Working with Halo Neuroscience in San Francisco, California, the sports group is testing whether stimulating the brain with electricity can improve the performance of ski jumpers by making it easier for them to hone their skills. Other research suggests that targeted brain stimulation can reduce an athlete’s ability to perceive fatigue1. Such technologies could aid recovery from injury or let athletes try 'brain doping' to gain a competitive advantage. Yet many scientists question whether brain stimulation is as effective as its proponents claim, pointing out that studies have looked at only small groups of people. “They’re cool findings, but who knows what they mean,” says cognitive psychologist Jared Horvath at the University of Melbourne in Australia. The USSA is working with Halo to judge the efficacy of a device that delivers electricity to the motor cortex, an area of the brain that controls physical skills. The company claims that the stimulation helps the brain build new connections as it learns a skill. It tested its device in an unpublished study of seven elite Nordic ski jumpers, including Olympic athletes. © 2016 Nature Publishing Group,
Keyword: Movement Disorders
Link ID: 21979 - Posted: 03.12.2016
By Amy Ellis Nutt Surgeons snaked the electrodes under the 65-year-old woman’s scalp. Thirty years of Parkinson’s disease had almost frozen her limbs. The wires, connected to a kind of pacemaker under the skin, were aimed at decreasing the woman’s rigidity and allowing for more fluid movement. But five seconds after the first electrical pulse was fired into her brain, something else happened. Although awake and fully alert, she seemed to plunge into sadness, bowing her head and sobbing. One of the doctors asked what was wrong. “I no longer wish to live, to see anything, to hear anything, feel anything,” she said. Was she in some kind of pain? “No, I’m fed up with life. I’ve had enough,” she replied. “Everything is useless.” The operating team turned off the current. Less than 90 seconds later, the woman was smiling and joking, even acting slightly manic. Another five minutes more, and her normal mood returned. The patient had no history of depression. Yet in those few minutes after the electrical pulse was fired, the despair she expressed met nine of the 11 criteria for severe major depressive disorder in the Diagnostic and Statistical Manual of Mental Disorders. Fascinated by the anomaly, the French physicians wrote up the episode for the New England Journal of Medicine. The year was 1999, and hers was one of the first documented cases of an electrically induced, instantaneous, yet reversible depression. © 1996-2016 The Washington Post
Laura Sanders For some adults, Zika virus is a rashy, flulike nuisance. But in a handful of people, the virus may trigger a severe neurological disease. About one in 4,000 people infected by Zika in French Polynesia in 2013 and 2014 got a rare autoimmune disease called Guillain-Barré syndrome, researchers estimate in a study published online February 29 in the Lancet. Of 42 people diagnosed with Guillain-Barré in that outbreak, all had antibodies that signaled a Zika infection. Most also had recent symptoms of the infection. In a control group of hospital patients who did not have Guillain-Barré, researchers saw signs of Zika less frequently: Just 54 out of 98 patients tested showed signs of the virus. The message from this earlier Zika outbreak is that countries in the throes of Zika today “need to be prepared to have adequate intensive care beds capacity to manage patients with Guillain-Barré syndrome,” writes study coauthor Arnaud Fontanet of the Pasteur Institute in Paris and colleagues, some of whom are from French Polynesia. The study, says public health researcher Ernesto Marques of the University of Pittsburgh, “tells us what I think a lot of people already thought: that Zika can cause Guillain-Barré syndrome.” As with Zika and the birth defect microcephaly (SN: 2/20/16, p. 16), though, more work needs to be done to definitively prove the link. Several countries currently hard-hit by Zika have reported upticks in Guillain-Barré syndrome. Colombia, for instance, usually sees about 220 cases of the syndrome a year. But in just five weeks between mid-December 2015 to late January 2016, doctors diagnosed 86 cases, the World Health Organization reports. Other Zika-affected countries, including Brazil, El Salvador and Venezuela, have also reported unusually high numbers of cases. © Society for Science & the Public 2000 - 2016. All rights reserved.
Mo Costandi People who are prone to falling and injuring and injuring themselves in middle age are at significantly increased risk of developing Parkinson’s Disease decades later, according to a new study by researchers in Sweden. The findings, published earlier this month in the open access journal PLoS Medicine, suggest that frailty – and especially an increased risk of falling and fracturing one’s hip – could be a marker for degenerative brain changes, which may occur decades before disease symptoms appear, and possibly aid in early diagnosis. Parkinson’s Disease is a progressive neurodegenerative disease characterised by the death of dopamine-producing neurons in a region of the midbrain called the substantia nigra. This causes the three main symptoms of tremor, muscle rigidity, and slow movements, which typically appear at around 60 years of age, and progress at varying rates. Although widely considered to be a movement disorder, Parkinson’s is also associated with cognitive impairments, which in severe cases can develop into full-blown dementia. Last year, Peter Nordström of Umeå University and his colleagues published the results of a large population study, in which they examined the medical records of all the approximately 1.35 million Swedish men conscripted at age 18 for compulsory military service between the years of 1969 and 1996. Looking specifically at measures of muscle strength, they found that those who scored lowest on handgrip and elbow flexion strength at the time of conscription were significantly more likely to develop Parkinson’s 30 years later. © 2016 Guardian News and Media Limited
Link ID: 21919 - Posted: 02.20.2016
By Gretchen Reynolds Some forms of exercise may be much more effective than others at bulking up the brain, according to a remarkable new study in rats. For the first time, scientists compared head-to-head the neurological impacts of different types of exercise: running, weight training and high-intensity interval training. The surprising results suggest that going hard may not be the best option for long-term brain health. As I have often written, exercise changes the structure and function of the brain. Studies in animals and people have shown that physical activity generally increases brain volume and can reduce the number and size of age-related holes in the brain’s white and gray matter. Exercise also, and perhaps most resonantly, augments adult neurogenesis, which is the creation of new brain cells in an already mature brain. In studies with animals, exercise, in the form of running wheels or treadmills, has been found to double or even triple the number of new neurons that appear afterward in the animals’ hippocampus, a key area of the brain for learning and memory, compared to the brains of animals that remain sedentary. Scientists believe that exercise has similar impacts on the human hippocampus. These past studies of exercise and neurogenesis understandably have focused on distance running. Lab rodents know how to run. But whether other forms of exercise likewise prompt increases in neurogenesis has been unknown and is an issue of increasing interest, given the growing popularity of workouts such as weight training and high-intensity intervals. So for the new study, which was published this month in the Journal of Physiology, researchers at the University of Jyvaskyla in Finland and other institutions gathered a large group of adult male rats. The researchers injected the rats with a substance that marks new brain cells and then set groups of them to an array of different workouts, with one group remaining sedentary to serve as controls. © 2016 The New York Times Company
Link ID: 21902 - Posted: 02.17.2016
By Sheena Goodyear, A brain implant the size of a paper-clip might one day help paralyzed people regain the ability to use their arms and legs via a wireless connection that will transmit their thoughts to an exoskeleton. It's not the first technology to allow paralyzed people to operate mechanical limbs with signals from their brain, but it has the potential to revolutionize the field because it's minimally invasive and totally wireless. It's made possible because of a matchstick-sized implant called a stentrode, crafted from nitinol, an alloy that is commonly used in brassiere underwires and eyeglass frames, according to a study published in the journal Nature Biotechnology. "It's really a new method for getting brain data out of the brain without performing brain surgery," Thomas Oxley, a neurologist at the University of Melbourne who designed the device, told CBC News. "Part of the reason that brain-machine interfaces have not been successful to this point is because they get rejected by the body, and the reason they get rejected is because they all require direct implantation into the brain. And to do that you have to take off the skull — you have to perform a craniotomy." ©2016 CBC/Radio-Canada.
Link ID: 21886 - Posted: 02.11.2016
Jo Marchant The brain cells of people with Parkinson’s disease can be trained to reliably respond to placebo drugs, Italian neuroscientists report. The training wears off after 24 hours but the effect shows it may be possible to reduce the medication needed to treat Parkinson’s by interspersing real drugs with inert injections or pills, says placebo researcher Fabrizio Benedetti at the University of Turin, Italy, who led the work. A few people with Parkinson’s disease do respond dramatically to placebos, but most do not1. People with the condition suffer characteristic tremors and stiff muscles because their dopamine-producing brain cells are gradually dying off. They alleviate their symptoms by taking drugs such as apomorphine, which activate receptors for dopamine. For some conditions — such as pain and immune disorders — trials have shown2 that it is possible to train people to respond to placebos, although this practice hasn’t made its way into clinical care. Benedetti and his colleagues wondered whether the same effect might be possible for neurological disorders. They studied 42 people with advanced Parkinson’s disease who were having electrodes implanted into their brains for a therapy called deep brain stimulation, which eases symptoms by stimulating affected brain areas directly. That surgery gave Benedetti’s team a rare opportunity to measure the activity of individual neurons in the thalamus, a brain region known to be inhibited by lack of dopamine in people with Parkinson's. © 2016 Nature Publishing Grou
Link ID: 21884 - Posted: 02.10.2016
Colombia says three people have died after contracting the Zika virus and developing a rare nerve disorder. Health Minister Alejandro Gaviria said there was a "causal connection" between Zika, the Guillain-Barre disorder and the three deaths. Earlier, Brazilian scientists said they had detected for the first time active samples of Zika in urine and saliva. However, it is not clear whether the virus can be transmitted through bodily fluids. Zika, a mosquito-borne disease, has been linked to cases of babies born in Brazil with microcephaly - underdeveloped brains. "We have confirmed and attributed three deaths to Zika," said the head of Colombia's National Health Institute, Martha Lucia Ospina. "In this case, the three deaths were preceded by Guillain-Barre syndrome." Guillain-Barre is a rare disorder in which the body's immune system attacks part of the nervous system. It isn't normally fatal. Ms Ospina said another six deaths were being investigated for possible links to Zika. "Other cases (of deaths linked to Zika) are going to emerge," she said. "The world is realising that Zika can be deadly. The mortality rate is not very high, but it can be deadly." Mr Gaviria said one of the fatalities took place in San Andres and the other two in Turbo, in Antioquia department. UK virologist Prof Jonathan Ball, of the University of Nottingham, told the BBC: "We have been saying Zika has been associated with Guillain-Barre. One of the complications of that could be respiratory failure. But it is still probably a very rare event." Although Zika usually causes mild, flu-like symptoms, it has been linked to thousands of suspected birth defects. However, it has not yet been proved that Zika causes either microcephaly or Guillain-Barre. © 2016 BBC
By Anne Pycha Future doctors may ask us to say more than “Ahhh.” Several groups of neuroscientists, psychiatrists and computer scientists are now investigating the extent to which patients' language use can provide diagnostic clues—before a single laboratory test is run. Increased computing power and new methods to measure the relation between behavior and brain activity have advanced such efforts. And although tests based on the spoken word may not be as accurate as gene sequencing or MRI scans, for diseases lacking clear biological indicators, language mining could help fill the gap. Psychiatrists at Columbia University interviewed 34 young adults at risk for psychosis, a common sign of schizophrenia that includes delusions and hallucinations. Two and a half years later five of the subjects had developed psychosis, and the remaining 29 remained free of the disorder. A specially designed algorithm combed the initial interviews collectively to look for language features that distinguished the two groups and found that psychosis correlated with shorter sentences, loss of flow in meaning from one sentence to the next and less frequent use of the words “that,” “what” and “which.” When later tested on each individual interview, the computer program predicted who did and who did not develop psychosis with 100 percent accuracy. The results were recently published in Schizophrenia, and a second round of testing with another group of at-risk subjects is now under way. Parkinson's Disease Twenty-seven subjects in a study at Favaloro University in Argentina listened to recorded sentences containing verbs associated with specific hand shapes (such as “applaud” or “punch”). As soon as they understood the sentence, participants pressed a button while keeping both hands in either a flat or clenched-fist position. © 2016 Scientific American
Videos just discovered show the first people ever to be treated for the symptoms of Parkinson’s disease. The footage, hidden for half a century, shows Chilean miners with severe movement problems improving on daily doses of L-dopa. The videos were filmed by George Cotzias at Brookhaven National Laboratory in Upton, New York. In 1963, while studying the toxic effects of manganese in human tissues, Cotzias learned of four workers in the Corral del Quemado mine in Andacollo, Chile, who had developed a syndrome called manganism – which resembled Parkinson’s – through inhaling manganese dust. Cotzias travelled to Chile to include the miners in a trial of leva-dopa, a chemical building block that the body converts into dopamine, low levels of which cause uncontrolled movements in people with Parkinson’s. L-dopa was being tested in Parkinson’s patients around the same time but with little success – even small amounts caused adverse side-effects that prevented a high enough dose reaching the brain. The footage clearly shows the severe problems with walking and turning miners had before treatment. After several months of receiving a daily dose of L-dopa, they were able to feed themselves, shave, tie their shoelaces, and run. “It’s a very important part of the history of neurology,” says Marcelo Miranda, a researcher at Clinica Las Condes in Santiago, Chile, who found the footage, some of which was shown at a conference in the 1960s, but hasn’t been seen since. “It’s the only available document of that period that shows the first patients with Parkinson’s symptoms treated with L-dopa and their extraordinary response.” © Copyright Reed Business Information Ltd.
Link ID: 21811 - Posted: 01.23.2016
The Chamorro people of the Pacific island of Guam know it as lytigo-bodig. For decades, they have been struck down by a mysterious illness that resembles the muscle-wasting disease amyotrophic lateral sclerosis (ALS), Parkinson’s disease and Alzheimer’s-like dementia. It now looks like we have a clue that could point to a way of slowing its development. Lytigo-bodig is a progressive disease. ALS symptoms arrive when people are in their mid-40s and early 50s. By the time they reach their 60s, they also have the shaking and lack of coordination that characterises Parkinson’s, before the cognitive problems associated with dementia also set in. “Initially they stumble a bit, but as their muscles wither, they need help with eating and going to the toilet, as well as having difficulty swallowing and breathing,” says Paul Cox of the Institute for Ethnomedicine in Wyoming. For a long time, a chemical called BMAA, found in the cycad seeds that the Chamorro grind up to make flour, has been suspected as the cause of the disease. The toxin builds up in the cyanobacteria that grow in the roots of cycad plants. It also accumulates in the tissue of seed-eating flying foxes, which the Chamorro hunt and eat. To see if they could confirm BMAA as the culprit, Cox fed fruit spiked with the toxin to vervet monkeys for 140 days. They estimated this was equivalent to the dose a typical islander might get over a lifetime. Although they didn’t show cognitive problems, the animals did develop brain abnormalities called tau tangles and deposits of amyloid plaque. The density and placement of these abnormalities were similar to those seen in the islanders. “The structure of the pathology is almost identical,” says Cox. “We were stunned.” © Copyright Reed Business Information Ltd.