Two minutes of magnetic stimulation can change your brain for an hourJanuary 17, 2005A couple of minutes is all it takes to 'knock out' bits of your brain for an hour, according to a new study by a University College London (UCL) team. The team have been working on ways to improve a method known as transcranial magnetic stimulation (TMS) and are now using their adapted version of TMS to investigate possible treatments for stroke patients or those with Parkinson's disease. In the latest issue of the journal Neuron, Professor John Rothwell and colleagues from UCL's Institute of Neurology discovered ways to improve TMS to produce effects on the brain that last for more than an hour after only 40 seconds of stimulation. Longer-lasting effects will enable scientists to use TMS to modify brain activity in conditions ranging from depression to brain damage. TMS stimulates the brain via a magnetic coil held outside the skull which can be moved over different parts of the brain. The magnetic fields created by the coil induce tiny electrical currents inside the skull that alter the activity of neural pathways, stimulating or inhibiting activity in parts of the brain. The technique has been used predominantly as a research tool to study how the healthy brain reacts to injury or damage but scientists have recently started to explore its possibilities as a treatment for depression, epilepsy, stroke and Parkinson's disease. A handful of studies have already shown potential therapeutic benefits from TMS. The advantage of TMS is that it is non-invasive and does not require a patient to be hospitalized i.e. the treatment can be given in an out-patient clinic. However, the drawback in the past has been that TMS led to only transient neurological effects which rarely lasted longer than 30 minutes. The new method pioneered by the UCL team holds promise that much longer lasting and more powerful effects can be produced. Professor Rothwell's team adapted the technique by testing different patterns of repetitive magnetic pulses to the scalps of volunteers, delivered over a period of 20 to 190 seconds. The pulses were aimed at the motor cortex that controls muscle response, because effects on the motor cortex can be objectively measured by recording the amount of electrical muscle response to stimulation. The researchers positioned the magnetic coil over the motor cortex area that controls hand movement and measured the amount of muscle response in a small muscle in the subjects' hands. They discovered that the excitatory effect of TMS builds up rapidly, within about a second, while the inhibitory effect builds up within several seconds. Thus, by adjusting the length of stimulation, they could choose between stimulating or suppressive effects on the brain. The team were able to produce rapid, consistent and controllable changes in the motor cortex area, lasting double the amount of time of conventional TMS. Initial tests performed to assess the safety of TMS showed that there were no long-lasting or side effects from these stimulations. Professor Rothwell says: "Now that we have improved the technique, we can use it to explore whether stimulation of damaged areas in stroke patients' brains can help speed up their recovery. Alternatively, it may be that in some patients the 'healthy' side of the brain interferes with recovery by the damaged side, so that another approach would be to reduce its activity and stop it competing for control." Rothwell's team are also investigating the possibility of applying the method to patients with Parkinson's disease or dystonia. University College London - UCL |
|||||||||||||||||||||
| Related Stroke Current Events and Stroke News Articles Surgery not linked to memory problems in older patients For years, it has been widely assumed that older adults may experience memory loss and other cognitive problems following surgery. But a new study from researchers at Washington University School of Medicine in St. Louis questions those assumptions. Pushing the brain to find new pathways Until recently, scientists believed that, following a stroke, a patient had about six months to regain any lost function. After that, patients would be forced to compensate for the lost function by focusing on their remaining abilities. Night Beat, Overtime and a Disrupted Sleep Pattern Can Harm Officers' Health A police officer who works the night shift, typically from 8 p.m. to 4 a.m., already is at a disadvantage when it comes to getting a good "night's" sleep. Vitamin B niacin offers no extra benefit to statin therapy in seniors already diagnosed with CAD The routine prescription of extended-release niacin, a B vitamin (1,500 milligrams daily), in combination with traditional cholesterol-lowering therapy offers no extra benefit in correcting arterial narrowing and diminishing plaque buildup in seniors who already have coronary artery disease, a new vascular imaging study from Johns Hopkins experts shows. The benefits of exercise Physical exercise is one of the most effective methods of preventing disease. The current issue of Deutsches Arzteblatt International is devoted to this important topic. Heart and bone damage from low vitamin D tied to declines in sex hormones Researchers at Johns Hopkins are reporting what is believed to be the first conclusive evidence in men that the long-term ill effects of vitamin D deficiency are amplified by lower levels of the key sex hormone estrogen, but not testosterone. New study links vitamin D deficiency to cardiovascular disease and death While mothers have known that feeding their kids milk builds strong bones, a new study by researchers at the Heart Institute at Intermountain Medical Center in Salt Lake City suggests that Vitamin D contributes to a strong and healthy heart as well - and that inadequate levels of the vitamin may significantly increase a person's risk of stroke, heart disease, and death, even among people who've never had heart disease. Early end to key study on benefits of niacin, a B vitamin, in keeping arteries open was premature Heart experts at Johns Hopkins are calling premature the early halt of a study by researchers at Walter Reed Army Medical Center and Washington Hospital Center on the benefits of combining extended-release niacin, a B vitamin, with cholesterol-lowering statin medications to prevent blood vessel narrowing. Study finds many people with hemianopia have difficulty detecting pedestrians while driving, advocates for individual testing Schepens Eye Research Institute scientists have found that--when tested in a driving simulator--patients with hemianopia (blindness in one half of the visual field in both eyes) have significantly more difficulty detecting pedestrians (on their blind side) than normally sighted people. Texas Children's discharges first pediatric patient with implanted mechanical heart device Texas Children's Hospital is the nation's first pediatric hospital to discharge a child while on an intracorporeal ventricular assist device (VAD), a feat previously accomplished only at adult institutions. More Stroke Current Events and Stroke News Articles |
|||||||||||||||||||||
|
|||||||||||||||||||||
|
|||||||||||||||||||||