Carl Zimmer In 1998, Dr. Philip A. Starr started putting electrodes in people’s brains. A neurosurgeon at the University of California, San Francisco, Dr. Starr was treating people with Parkinson’s disease, which slowly destroys essential bits of brain tissue, robbing people of control of their bodies. At first, drugs had given his patients some relief, but now they needed more help. After the surgery, Dr. Starr closed up his patients’ skulls and switched on the electrodes, releasing a steady buzz of electric pulses in their brains. For many patients, the effect was immediate. “We have people who, when they’re not taking their meds, can be frozen,” said Dr. Starr. “When we turn on the stimulator, they start walking.” First developed in the early 1990s, deep brain stimulation, or D.B.S., was approved by the Food and Drug Administration for treating Parkinson’s disease in 2002. Since its invention, about 100,000 people have received implants. While D.B.S. doesn’t halt Parkinson’s, it can turn back the clock a few years for many patients. Yet despite its clear effectiveness, scientists like Dr. Starr have struggled to understand what D.B.S. actually does to the brain. “We do D.B.S. because it works,” said Dr. Starr, “but we don’t really know how.” In a recent experiment, Dr. Starr and his colleagues believe they found a clue. D.B.S. may counter Parkinson’s disease by liberating the brain from a devastating electrical lock-step. The new research, published on Monday in Nature Neuroscience, may help scientists develop better treatments for Parkinson’s disease. It may also help researchers adapt D.B.S. for treatment of such brain disorders as depression and obsessive compulsive disorder. © 2015 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 20817 - Posted: 04.18.2015

Jane Brody The Holy Grail in any progressive disease is to find it early enough to start effective treatment before irreversible damage has occurred. For Parkinson’s disease, which afflicts 1.5 million Americans and growing, a new study has brought this goal a little closer. The study, conducted among more than 54,000 British men and women, identified a slew of symptoms that were more likely to be present in people who years later were diagnosed with Parkinson’s. The findings underscore the prevailing view among neurologists that the damage caused by this disease begins long before classic symptoms like tremors, rigidity and an unsteady gait develop and a definite diagnosis can be made. The study, by Dr. Anette Schrag and fellow neurologists at the University College London, was published in The Lancet in January. As many as five years before a diagnosis of Parkinson’s, those who developed it were more likely to have experienced tremor, balance problems, constipation, low blood pressure, dizziness, erectile and urinary dysfunction, fatigue, depression and anxiety. In addition, Dr. Claire Henchcliffe, director of the Parkinson’s Disease and Movement Disorders Institute at Weill Cornell Medical Center, said that REM sleep behavior disorder, characterized by a tendency to act out one’s dreams while asleep, is one of the strongest prediagnostic symptoms, along with a lost sense of smell and subtle changes in cognition. Dr. Melissa J. Nirenberg, a Parkinson’s disease specialist at New York University Medical Center, said, “Up to 80 percent of people with the sleep disorder get Parkinson’s or a similar neurodegenerative disease.” © 2015 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 14: Biological Rhythms, Sleep, and Dreaming
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 10: Biological Rhythms and Sleep
Link ID: 20698 - Posted: 03.19.2015

By JON PALFREMAN EUGENE, Ore. — FOUR years ago, I was told I had Parkinson’s disease, a condition that affects about one million Americans. The disease is relentlessly progressive; often starting with a tremor in one limb on one side of the body, it spreads. The patient’s muscles become more rigid, frequently leading to a stooped posture, and movements slow down and get smaller and less fluid. As the disease advances — usually over a number of years — the patient becomes more and more disabled, experiencing symptoms from constipation to sleep disorders to cognitive impairment. Can Parkinson’s be slowed, stopped or even reversed? Can the disease be prevented before it starts, like polio and smallpox? More than at any time in history, success seems possible. Having sequenced the human genome, biomedical researchers have now set their sights on the ultimate frontier — the human brain. The formidable puzzle is to figure out how a three-pound lump of mostly fatty matter enables us to perform a seemingly endless number of tasks, like walking, seeing, hearing, smelling, tasting, touching, thinking, loving, hating, speaking and writing ... and why those awesome abilities break down with neurological disease. Many scientists view Parkinson’s as a so-called pathfinder. If they can figure out what causes Parkinson’s, it may open the door to understanding a host of other neurodegenerative diseases — and to making sense of an organ of incredible complexity. In Parkinson’s, the circuitry in a tiny region of the brain called the basal ganglia becomes dysfunctional. Along with the cerebellum, the basal ganglia normally acts as a kind of adviser that helps people learn adaptive skills by classic conditioning — rewarding good results with dopamine bursts and punishing errors by withholding the chemical. Babies rely on the basal ganglia to learn how to deploy their muscles to reach, grab, babble and crawl, and later to accomplish many complex tasks without thinking. For example, when a tennis player practices a stroke over and over again, the basal ganglia circuitry both rewards and “learns” the correct sequence of activities to produce, say, a good backhand drive automatically. © 2015 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20606 - Posted: 02.24.2015

By Lenny Bernstein Parkinson's Disease patients secretly treated with a placebo instead of their regular medication performed better when told they were receiving a more expensive version of the "drug," researchers reported Wednesday in an unprecedented study that involved real patients. The research shows that the well-documented "placebo effect" -- actual symptom relief brought about by a sham treatment or medication -- can be enhanced by adding information about cost, according to the lead author of the study. It is the first time that concept has been demonstrated using people with a real illness, in this case Parkinson's, a progressive neurological disease that has no cure, according to an expert not involved in the study. "The potentially large benefit of placebo, with or without price manipulations, is waiting to be untapped for patients with [Parkinson's Disease], as well as those with other neurologic and medical diseases," the authors wrote in a study published online Wednesday in the journal Neurology. But deceiving actual patients in a research study raised ethical questions about violating the trust involved in a doctor-patient relationship. Most studies in which researchers conceal their true aims or other information from subjects are conducted with healthy volunteers. This one was subjected to a lengthy review before it was allowed to proceed, and, in an editorial that accompanied the article, two other physicians wrote that "the authors do not mention whether there was any possible effect (reduction) on trust in doctors or on willingness to engage in future clinical research."

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 8: General Principles of Sensory Processing, Touch, and Pain
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 5: The Sensorimotor System
Link ID: 20542 - Posted: 02.02.2015

By SAM ROBERTS When he was just 5 years old, Thomas Graboys declared that he intended to become a doctor. As a young physician, he visited a nephew serving in the Peace Corps in Mauritania and remained for two months, treating dozens of patients a day. He skied and played tennis and joined fellow cardiologists as the drummer in a rock band called the Dysrhythmics. In Boston, he was famous as a member of the team that diagnosed the Celtics star Reggie Lewis’s heart defect before he died abruptly on a basketball court. In short, “he was a medical version of one of Tom Wolfe’s masters of the universe,” one reviewer concluded after Dr. Graboys (pronounced GRAY-boys) published his autobiography. But barely 60, after experiencing horrific nightmares, frequently flailing in bed, losing his memory, suffering tremors and finally collapsing on his wedding day, he acknowledged that he was suffering from Parkinson’s disease and the onset of dementia. He informed his patients that he had no choice but to close his practice. “My face is often expressionless, though I still look younger than my 63 years,” he recalled in the autobiography, “Life in the Balance: A Physician’s Memoir of Life, Love, and Loss With Parkinson’s Disease and Dementia,” which was published in 2008. “I am stooped,” he continued. “I shuffle when I walk, and my body trembles. My train of thought regularly runs off the rails. There is no sugarcoating Parkinson’s. There is no silver lining here. There is anger, pain, and frustration at being victimized by a disease that can to some extent be managed but cannot be cured.” After managing for more than a decade, Dr. Graboys died on Jan. 5 at his home in Chestnut Hill, Mass., his daughter, Penelope Graboys Blair, said. The cause was complications of Lewy Body Dementia, which was diagnosed after his Parkinson’s. He was 70. © 2015 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20485 - Posted: 01.15.2015

Stem cells can be used to heal the damage in the brain caused by Parkinson's disease, according to scientists in Sweden. They said their study on rats heralded a "huge breakthrough" towards developing effective treatments. There is no cure for the disease, but medication and brain stimulation can alleviate symptoms. Parkinson's UK said there were many questions still to be answered before human trials could proceed. The disease is caused by the loss of nerve cells in the brain that produce the chemical dopamine ,which helps to control mood and movement. To simulate Parkinson's, Lund University researchers killed dopamine-producing neurons on one side of the rats' brains. They then converted human embryonic stem cells into neurons that produced dopamine. Parkinson's Disease Parkinson's is one of the commonest neurodegenerative diseases These were injected into the rats' brains, and the researchers found evidence that the damage was reversed. There have been no human clinical trials of stem-cell-derived neurons, but the researchers said they could be ready for testing by 2017. Malin Parmar, associate professor of developmental and regenerative neurobiology, said: "It's a huge breakthrough in the field [and] a stepping stone towards clinical trials." A similar method has been tried in a limited number of patients. It involved taking brain tissue from multiple aborted foetuses to heal the brain. Clinical trials were abandoned after mixed results, but about a third of the patients had foetal brain cells that functioned for 25 years. BBC © 2014

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 20292 - Posted: 11.08.2014

by Flora Graham This glowing blue web of neurons is usually what researchers examine when searching for a cure for Parkinson's. But a new study, part-funded by Parkinson's UK, hones in on the tiny yellow dots. These are the connections between brain cells known as synapses, has discovered a killer that targets these links, potentially paving the way for new treatments. Soledad Galli at University College London and her colleagues have found that the death of synapses in mice may be due to malfunctioning proteins called Wnt proteins. "If we confirm that Wnt is involved in the early stages of Parkinson's, this throws up exciting possibilities, not just for new treatment targets, but also for new ways to identify people with Parkinson's early on in their condition," says Galli. Most patients currently depend on the drug levodopa, which is over 50 years old and can have severe side-effects, in addition to becoming less effective over time. Moreover, it only masks the symptoms: there is no cure for Parkinson's and no way to stop its progression. Journal reference: Nature Communications, DOI: 10.1038/ncomms5992 © Copyright Reed Business Information Ltd

Related chapters from BN: 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 4: Development of the Brain
Link ID: 20214 - Posted: 10.18.2014

Posted by Rachel Dolhun, MD, The ability to quit smoking, especially “cold turkey” or on the first attempt, has been heralded as a marker of strong willpower and determination. But could the ease with which one eschews cigarettes also serve as an early sign of Parkinson’s disease (PD)? This is the conclusion drawn by Beate Ritz, MD, PhD, and colleagues from the University of California, Los Angeles in a recent study published in Neurology. Researchers compared lifelong tobacco use, use of nicotine substitutes, and individual’s rating of their difficulty in trying to quit tobacco among 1,808 Danish people with PD and 1,876 control volunteers. They found that those with PD were less inclined to ever pick up the smoking habit, but, even if they did, they were less likely to need nicotine replacement therapies and able to more effortlessly stop smoking cigarettes. Therefore, ease of quitting smoking may be a sign of early PD. This joins a short list of other symptoms — smell loss, constipation and REM sleep behavior disorder — that usually predate diagnosis and are strongly associated with PD. Physicians rely heavily on such information to help confirm the diagnosis of Parkinson’s, given that biomarkers, objective measurements of disease, are currently lacking. Research led by The Michael J. Fox Foundation is ongoing to identify biological markers of PD, which could help diagnose and treat people earlier. In the meantime, doctors must look for symptoms and behaviors to help identify Parkinson’s. Researchers have long known that tobacco use was linked to a lower risk of PD. An ongoing Foundation-funded study is investigating whether nicotine might guard against or slow the progression of PD.

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 4: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 3: The Chemistry of Behavior: Neurotransmitters and Neuropharmacology
Link ID: 20189 - Posted: 10.11.2014

By Lenny Bernstein Comedian Robin Williams was grappling with severe depression when he committed suicide Monday, and on Thursday we learned that he also was in the early stages of Parkinson's disease. Sadly, the two conditions are often found together. In a 2012 study conducted by the National Parkinson Foundation, 61 percent of 5,557 Parkinson's patients surveyed reported that they also suffered from depression, with symptoms that ranged from mild to severe. Both conditions are associated with a shortage of dopamine, a neurotransmitter that helps regulate movement and control the brain's pleasure center. "Dopamine is a feel-good chemical. If you are low in dopamine, you are not going to feel so good," said Joyce Oberdorf, president and CEO of the National Parkinson Foundation. "There are [also] other neurotransmitters that can be low." A separate study published Friday found that newly-diagnosed Parkinson's patients have higher rates of depression, anxiety, fatigue, and apathy than a control group of people without Parkinson's. Researchers from the Raymond and Ruth Perelman School of Medicine at the University of Pennsylvania found that 13.9 percent of patients had symptoms of depression when they were diagnosed with Parkinson's, a proportion that rose to 18.7 percent after 24 months. Just 6.6 percent of people without the disease had depression, and that dropped to just 2.4 percent after 24 months. Despite their depressive symptoms, most of the Parkinson's patients who also had that condition were not treated with anti-depressants at any point in the two-year study. The findings were published in the journal Neurology.

Related chapters from BN: Chapter 16: Psychopathology: Biological Basis of Behavior Disorders; Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 12: Psychopathology: The Biology of Behavioral Disorders; Chapter 5: The Sensorimotor System
Link ID: 19961 - Posted: 08.16.2014

Using data from over 18,000 patients, scientists have identified more than two dozen genetic risk factors involved in Parkinson’s disease, including six that had not been previously reported. The study, published in Nature Genetics, was partially funded by the National Institutes of Health (NIH) and led by scientists working in NIH laboratories. A gene chip. Scientists used gene chips to help discover new genes that may be involved with Parkinson's disease “Unraveling the genetic underpinnings of Parkinson’s is vital to understanding the multiple mechanisms involved in this complex disease, and hopefully, may one day lead to effective therapies,” said Andrew Singleton, Ph.D., a scientist at the NIH’s National Institute on Aging (NIA) and senior author of the study. Dr. Singleton and his colleagues collected and combined data from existing genome-wide association studies (GWAS), which allow scientists to find common variants, or subtle differences, in the genetic codes of large groups of individuals. The combined data included approximately 13,708 Parkinson’s disease cases and 95,282 controls, all of European ancestry. The investigators identified potential genetic risk variants, which increase the chances that a person may develop Parkinson’s disease. Their results suggested that the more variants a person has, the greater the risk, up to three times higher, for developing the disorder in some cases.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19889 - Posted: 07.29.2014

Maggie Fox NBC News Walking is an almost magic elixir, doctors like to say. It can reverse diabetes, lower blood pressure, and help people keep the fat off. Now a study shows it can also help people with Parkinson’s disease. Parkinson’s patients who walked just three times a week felt less tired, less depressed and they found their Parkinson’s symptoms improved, also. “The results of our study suggest that walking may provide a safe and easily accessible way of improving the symptoms of Parkinson’s disease and improve quality of life,” Dr. Ergun Uc of the University of Iowa and the Veterans Affairs Medical Center of Iowa City, who led the study. The findings would only apply to Parkinson’s patients who can still walk easily. Parkinson’s is caused by the loss of brain cells that produce a message carrying-chemical, or neurotransmitter, that is important for movement. Symptoms can start with a barely noticeable trembling but worsen to difficulty walking and talking, depression and other disability. There’s no cure and the drugs used to treat the condition usually stop helping over time. Some people have trouble walking. But for those who don’t, the study found, walking can help their symptoms. And other research suggests that regular exercise can help slow down the progression of Parkinson’s. Various programs show that dancing,cycling, Pilates and even boxing can help. But walking has a big advantage – people can do it anywhere, without special equipment, and on their own schedules.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19786 - Posted: 07.03.2014

by Laura Sanders Transplanted cells can flourish for over a decade in the brain of a person with Parkinson’s disease, scientists write in the June 26 Cell Reports. Finding that these cells have staying power may encourage clinicians to pursue stem cell transplants, a still-experimental way to counter the brain deterioration that comes with Parkinson’s. Penelope Hallett of Harvard University and McLean Hospital in Belmont, Mass., and colleagues studied postmortem brain tissue from five people with advanced Parkinson’s. The five had received stem cell transplants between four and 14 years earlier. In all five people’s samples, neurons that originated from the transplanted cells showed signs of good health and appeared capable of sending messages with the brain chemical dopamine, a neurotransmitter that Parkinson’s depletes. Results are mixed about whether these transplanted cells are a good way to ease Parkinson’s symptoms. Some patients have shown improvements after the new cells stitched themselves into the brain, while others didn’t benefit from them. The cells can also cause unwanted side effects such as involuntary movements. P. J. Hallett et al. Long-term health of dopaminergic neuron transplants in Parkinson’s disease patients. Cell Reports. Vol. 7, June 26, 2014. doi: 10.1016/j.celrep.2014.05.027. © Society for Science & the Public 2000 - 2013

Related chapters from BN: 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 4: Development of the Brain
Link ID: 19707 - Posted: 06.07.2014

Scientists may have discovered how the most common genetic cause of Parkinson’s disease destroys brain cells and devastates many patients worldwide. The study was partially funded by the National Institutes of Health’s National Institute of Neurological Disorders and Stroke (NINDS); the results may help scientists develop new therapies. The investigators found that mutations in a gene called leucine-rich repeat kinase 2 (LRRK2; pronounced “lark two” or “lurk two”) may increase the rate at which LRRK2 tags ribosomal proteins, which are key components of protein-making machinery inside cells. This could cause the machinery to manufacture too many proteins, leading to cell death. “For nearly a decade, scientists have been trying to figure out how mutations in LRRK2 cause Parkinson’s disease,” said Margaret Sutherland, Ph.D., a program director at NINDS. “This study represents a clear link between LRRK2 and a pathogenic mechanism linked to Parkinson’s disease.” Affecting more than half a million people in the United States, Parkinson’s disease is a degenerative disorder that attacks nerve cells in many parts of the nervous system, most notably in a brain region called the substantia nigra, which releases dopamine, a chemical messenger important for movement. Initially, Parkinson’s disease causes uncontrolled movements; including trembling of the hands, arms, or legs. As the disease gradually worsens, patients lose ability to walk, talk or complete simple tasks.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19477 - Posted: 04.12.2014

|By Bret Stetka The data confirm it: farmers are more prone to Parkinson’s than the general population. And pesticides could be to blame. Over a decade of evidence shows a clear association between pesticide exposure and a higher risk for the second most common neurodegenerative disease, after Alzheimer's. A new study published in Neurology proposes a potential mechanism by which at least some pesticides might contribute to Parkinson’s. Regardless of inciting factors — and there appear to be many — Parkinson’s ultimately claims dopamine-releasing neurons in a small, central arc of brain called the “substantia nigra pars compacta.” The nigra normally supplies dopamine to the neighboring striatum to help coordinate movement. Through a series of complex connections, striatal signals then find their way to the motor cortex and voila, we move. But when nigral neurons die, motor function goes haywire and the classic symptoms set in, including namely tremors, slowed movements, and rigidity. Pesticides first came under suspicion as potentially lethal to the nigra in the early 1980s following a tragic designer drug debacle straight out of Breaking Bad. Patients started showing up at Northern California ERs nearly unresponsive, rigid, and tremoring — in other words, severely Parkinsonian. Savvy detective work by neurologist Dr. William Langston and his colleagues, along with the Santa Clara County police, traced the mysterious outbreak to a rogue chemist and a bad batch. He’d been trying to synthesize a “synthetic heroin” — not the snow cone flavorings he claimed — however a powder sample from his garage lab contained traces of an impurity called MPTP. MPTP, it turned out, ravages dopaminergic neurons in the nigra and causes what looks like advanced Parkinson’s. All of the newly Parkinsonian patients were heroin users who had injected the tainted product. And MPTP, it also turned out, is awfully similar in structure to the widely used herbicide paraquat, leading some neurologists to turn their attention to farms and fields. © 2014 Scientific American

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19463 - Posted: 04.09.2014

by Catherine de Lange Why wait for the doctor to see you? A smart patch attached to your skin could diagnose health problems automatically – and even administer drugs. Monitoring movement disorders such as Parkinson's disease or epilepsy relies on video recordings of symptoms and personal surveys, says Dae-Hyeong Kim at the Seoul National University in South Korea. And although using wearable devices to monitor the vital signs of patients is theoretically possible, the wearable pads, straps and wrist bands that can do this are often cumbersome and inflexible. To track the progression of symptoms and the response to medication more accurately would require devices that monitor cues from the body, store recorded data for pattern analysis and deliver therapeutic agents through the human skin in a controlled way, Kim says. So Kim and his team have developed an adhesive patch that is flexible and can be worn on the wrist like a second skin. The patch is 1 millimetre thick and made of a hydrocolloid dressing – a type of thin flexible bandage. Into it they embedded a layer of silicon nanoparticles. These silicon nanomembranes are often used for flexible electronics, and can pick up the bend and stretch of human skin and convert these into small electronic signals. The signals are stored as data in separate memory cells made from layers of gold nanoparticles. The device could be used to detect and treat tremors in people who have Parkinson's disease, or epileptic seizures, says Kim. If these movements are detected, small heaters in the patch trigger the release of drugs from silicon nanoparticles. The patch also contains temperature sensors to make sure the skin doesn't burn during the process. © Copyright Reed Business Information Ltd.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19428 - Posted: 03.31.2014

Helen Shen For Frank Donobedian, sitting still is a challenge. But on this day in early January, he has been asked to do just that for three minutes. Perched on a chair in a laboratory at Stanford University in California, he presses his hands to his sides, plants his feet on the floor and tries with limited success to lock down the trembling in his limbs — a symptom of his Parkinson's disease. Only after the full 180 seconds does he relax. Other requests follow: stand still, lie still on the floor, walk across the room. Each poses a similar struggle, and all are watched closely by Helen Bronte-Stewart, the neuroscientist who runs the lab. “You're making history,” she reassures her patient. “Everybody keeps saying that,” replies the 73-year-old Donobedian, a retired schoolteacher, with a laugh. “But I'm not doing anything.” “Well, your brain is,” says Bronte-Stewart. Like thousands of people with Parkinson's before him, Donobedian is being treated with deep brain stimulation (DBS), in which an implant quiets his tremors by sending pulses of electricity into motor areas of his brain. Last October, a team of surgeons at Stanford threaded the device's two thin wires, each with four electrode contacts, through his cortex into a deep-seated brain region known as the subthalamic nucleus (STN). But Donobedian's particular device is something new. Released to researchers in August 2013 by Medtronic, a health-technology firm in Minneapolis, Minnesota, it is among the first of an advanced generation of neurostimulators that not only send electricity into the brain, but can also read out neural signals generated by it. On this day, Bronte-Stewart and her team have temporarily turned off the stimulating current and are using some of the device's eight electrical contacts to record abnormal neural patterns that might correlate with the tremors, slowness of movement and freezing that are hallmarks of Parkinson's disease. © 2014 Nature Publishing Group,

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19387 - Posted: 03.20.2014

by Ashley Yeager With a little help from implanted electrodes, Parkinson's patients make fewer driving errors, at least on a computer. When steering a simulator, patients with active brain stimulators averaged 3.8 driving errors, compared with 7.5 for healthy people and 11.4 for those with Parkinson's disease who did not have implants. The Parkinson’s patients’ driving skills were also more accurate when receiving deep brain stimulation than when taking levodopa, a common treatment for the disease, researchers report December 18 in Neurology. © Society for Science & the Public 2000 - 2013

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 19054 - Posted: 12.19.2013

Scientists at the National Institutes of Health have used RNA interference (RNAi) technology to reveal dozens of genes which may represent new therapeutic targets for treating Parkinson’s disease. The findings also may be relevant to several diseases caused by damage to mitochondria, the biological power plants found in cells throughout the body. “We discovered a network of genes that may regulate the disposal of dysfunctional mitochondria, opening the door to new drug targets for Parkinson’s disease and other disorders,” said Richard Youle, Ph.D., an investigator at the National Institute of Neurological Disorders and Stroke (NINDS) and a leader of the study. The findings were published online in Nature. Dr. Youle collaborated with researchers from the National Center for Advancing Translational Sciences (NCATS). Mitochondria are tubular structures with rounded ends that use oxygen to convert many chemical fuels into adenosine triphosphate, the main energy source that powers cells. Multiple neurological disorders are linked to genes that help regulate the health of mitochondria, including Parkinson’s, and movement diseases such as Charcot-Marie Tooth Syndrome and the ataxias. Some cases of Parkinson’s disease have been linked to mutations in the gene that codes for parkin, a protein that normally roams inside cells, and tags damaged mitochondria as waste. The damaged mitochondria are then degraded by cells’ lysosomes, which serve as a biological trash disposal system. Known mutations in parkin prevent tagging, resulting in accumulation of unhealthy mitochondria in the body.

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 18975 - Posted: 11.26.2013

Helen Shen Long used to treat movement disorders, deep-brain stimulation (DBS) is rapidly emerging as an experimental therapy for neuropsychiatric conditions including depression, Tourette’s syndrome, obsessive–compulsive disorder and even Alzheimer’s disease. But despite some encouraging results in patients, it remains largely unknown how the electrical pulses delivered by implants deep within the brain affect neural circuits and change behaviour. Now there is a prototype DBS device that could provide some answers, researchers reported on 10 November at the Society for Neuroscience’s annual meeting in San Diego, California. Called Harmoni, the device is the first DBS implant to monitor electrical and chemical responses in the brain while delivering electrical stimulation. “That’s new data that we haven’t really had access to in humans before,” says Cameron McIntyre, a biomedical engineer at Case Western Reserve University in Cleveland, Ohio, who is not involved in the work. Researchers hope that the device will identify the electrical and chemical signals in the brain that correlate in real time with the presence and severity of symptoms, including the tremors experienced by people with Parkinson’s disease. This information could help to uncover where and how DBS exerts its therapeutic effects on the brain, and why it sometimes fails, says Kendall Lee, a neurosurgeon at the Mayo Clinic in Rochester, Minnesota, who is leading the project. The results come at a time of great excitement in the DBS field. Last month, the US government's Defense Advanced Research Projects Agency (DARPA) announced a 5-year, US$70-million initiative to support development of the next generation of therapeutic brain-stimulating technologies. © 2013 Nature Publishing Group,

Related chapters from BN: Chapter 11: Motor Control and Plasticity; Chapter 3: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Related chapters from MM:Chapter 5: The Sensorimotor System; Chapter 2: Neurophysiology: The Generation, Transmission, and Integration of Neural Signals
Link ID: 18922 - Posted: 11.13.2013

By PAM BELLUCK It is probably no accident that the pivotal object in Martin Cruz Smith’s newest detective thriller, “Tatiana,” is a notebook nobody can read. Early on, Mr. Smith worried that his novel, being published Tuesday by Simon & Schuster, would be unreadable too — or wouldn’t be written at all. Author of the 1981 blockbuster “Gorky Park” and many acclaimed books since, Mr. Smith writes about people who uncover and keep secrets. But for 18 years, he has had a secret of his own. In 1995, he received a diagnosis of Parkinson’s disease. But he kept it hidden, not only from the public, but from his publisher and editors. He concealed it, although for years, tremors and stiffness have kept him from taking detailed notes and sketching people, places and objects for his research — and even as he became unable to type the words he needed to finish his 2010 best seller “Three Stations.” “I didn’t want to be judged by that,” Mr. Smith, 71, explained recently in his light-filled Victorian home north of San Francisco. “Either I’m a good writer or I’m not. ‘He’s our pre-eminent Parkinson’s writer.’ Who needs that?” In talking about his Parkinson’s odyssey, including a relatively new but promising treatment, Mr. Smith is opening a window on the still incurable disorder affecting four million people worldwide, a disease that is becoming increasingly prevalent as baby boomers age. His experience reflects a common desire to conceal often-stigmatizing symptoms, like shaking, slowness, and rigidity. (He mostly didn’t mind his Parkinsonian hallucinations: a black cat in his lap, whirlwinds spiraling from computer keys, a butler, a British military officer in full regalia. “Having hallucinations for a fiction writer is redundant,” he said.) Copyright 2013 The New York Times Company

Related chapters from BN: Chapter 11: Motor Control and Plasticity
Related chapters from MM:Chapter 5: The Sensorimotor System
Link ID: 18914 - Posted: 11.12.2013