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This is your brain on electricity
This is the title of an excellent article by Noah Shachtman, a NY-based freelance writer, published online in Wired Magazine. Maybe the whole point is well characterized by a statement made by Dr Rodolfo Llinás, chairman of the physicology and neuroscience department at the New York University School of Medicine: "All brain activity is basically electrical chattering between cells". Shachtman says that Dr Rajesh Pahwa, associate professor of neurology at University of Kansas Medical Center, has implanted hundreds of brain pacemakers, which by emitting electrical impulses into the brain - a process known as Deep Brain Stimulation (DBS) - are supposed to wake up particular cell groups which start "talking" too slowly, developing a sluggish, sleep-like rhythm. This waking up minimizes the effects of diseases such as Parkinson´s, obsessive-compulsive disorder and depression. Dr Pahwa says that 80 percent of his pacemakered patients with Parkinson´s showed significant improvement - with a 40 percent reduction in need for medication and a 40 to 50 percent reduction of symptoms. He has other stats, though. These devices are implanted incorrectly about 20 percent of the time, necessitating repeat surgery. Another 10 percent of the time , the hardware fails. There is also about a 3 percent risk of bleeding in the brain, which in very rare circumstances can cause a stroke or a coma. That´s why Llinás says he´s against electrode implantation. Carol Carey, a 48-year-old retired teacher in Leavenworth, Kansas, was "tremoring all of the time", and the medicines designed to remove the tremors would send her into uncontrolled twitching and bouts of hyperactivity. So surgeons implanted two pager-sized battery packs near her collarbone and wires into her brain´s subthalamic nucleus. Electric pulses from these devices have quieted her tremors enough to allow her to cut her medical intake in half and to start driving and eating on her own again. But these 5-10-hour surgeries must be done while the patient is awake - and unmedicated. Shachtman says that another model of pacemaker attempts to sidestep the complications described by Dr Pahwa by implanting the wires into the vagus nerve, one of the brain´s major pathways to and from the uppper torso, which is located around the neck, near the brain stem. Known as Vagus Nerve Stimulation (VNS), this procedure has been approved in the U. S. for the treatment of epilectic seizures. Many researchers across the country are investigating the effects of VNS on people with long-term medication-resistant depression. Some researchers at Lenox Hill Hospital in NY are looking into VNS as a treatment for obesity, since many scientists believe the vagus nerve passes along information from the stomach to the brain. The precise mechanisms behind why VNS works are still largely a mystery, and Dr Mitchel Kling, a psychiatry professor at the University of Maryland School of Medicine, says that "we´re only guessing at what the chemical basis for this thing might be", and that´s why, in contrast,. Dr Llinás prefers chemical therapies, because drugs like dopamine are "incredibly precise" as they only interact with the cells that have receptors for the chemical. Surgeons at Cornell University seem to be doing the most interesting experiment with Deep Brain Stimulation: they use the pacemaker to try to revive people in minimally conscious states, a procedure that in the future can lead to something odd (and hopefuly wonderful) in the presence of cerebral death. Related news:
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