Brain 'Pacemaker' Shows Good Results in Parkinson's Patients
July 26, 2000 -- More than half of the patients who had an electronic 'pacemaker' implanted in their brains to control their Parkinson's disease did so well that they were able to stop taking their medication entirely, according to a study published in the latest issue of Archives of Neurology. But Parkinson's patients shouldn't necessarily yet ask their doctor for the procedure, because it has a risk of serious side effects and it doesn't work for everyone, experts caution.
"This is not therapy everyone should run out and get," says Fred Wooten, MD, "There are complications." Wooten is chairman of the neurology department and director of the movement disorder program at the University of Virginia in Charlottesville.
Parkinson's disease is a chronic neurological condition named after James Parkinson, a London physician who first described the syndrome in 1817. The disease causes a reduction in dopamine, a chemical found in the brain. This decrease in dopamine can produce one or more of the classic signs of Parkinson's disease, including tremors, slow movement, stiffness, and walking or balance problems. It affects an estimated 1.5 million Americans, most of them over age 50.
There is no cure for Parkinson's, but for many years, the main treatment was a drug called levodopa, which is a chemical similar to dopamine. However, in the last 20 years, more and more research has focused on surgical treatments for Parkinson's. These involve removing small parts of the brain that that doctors believe aren't functioning properly and causing the Parkinson's symptoms. Many patients, including actor Michael J. Fox, have reported improvements in their symptoms after the surgery.
In this newest procedure, called subthalamic nucleus (STN) stimulation, surgeons implant a wire into the brain so that the tip of it sits in a region of the brain involved with movement. The other end of the wire is connected to a computer -- a small box about the size of a heart pacemaker -- that is placed under the skin in front of the chest. The computer is programmed to stimulate four or five different sites in the brain that are involved with Parkinson's.
In the new study, Jose L. Molinueva, MD, and colleagues at the University Hospital Clinic in Barcelona, Spain, used STN stimulation on 15 patients, average age 61, with advanced Parkinson's disease. All the patients were taking levodopa. The researchers wanted to see whether the procedure would work well enough to allow them to stop taking levodopa entirely.
In all patients, stiffness and tremor were significantly reduced after the surgery, and eight patients stopped taking levodopa or similar medications entirely at the end of the six-month follow-up period. Those patients who continued taking levodopa were able to greatly reduce the amount they needed to control their symptoms.