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------------------------------------------------------------------------ Brain Surgery Helps Parkinson's ------------------------------------------------------------------------ NEW YORK, Oct 08 (Reuters) -- An operation in which brain cells are destroyed by an electric current may offer at least two years of significant symptom relief in people with advanced Parkinson's disease, according to a study in The New England Journal of Medicine this week. The report from Canada says the operation, called pallidotomy, helped reduce the uncontrollable movements (dyskinesias), side effects of levodopa (L-dopa), an anti-Parkinson's medication. According to Dr. Anthony Lang, director of the Movement Disorders Centre at Toronto Hospital in Ontario, Canada, this is the largest and longest follow-up of pallidotomy in Parkinson's patients. "Pallidotomy is a very old treatment -- first performed in the 1960s -- that has been updated and reapplied to patients with Parkinson's disease, typically those who are suffering from a number of problems in the late stages of their illness that are either poorly resolved with the available medication or who have complications with the available medication," the neurologist says. Lang explains the surgery involves "mapping" a small area of the brain using very fine electrodes that are implanted into the brain to record nerve cell activity. Because the right motor regions of the brain control movement on the left side of the body, and vice versa, the surgery was performed on the side of the brain opposite the most affected side of the patient's body. Patients are awake during the procedure and move their bodies in response to the electrical stimulation to nerve cells supplied via the electrodes. This allows the surgeon to "localize" the areas associated with specific movements. "So using these microelectrodes, the surgeon maps the part of the brain of interest, and records where the parts of the brain that he wants to avoid are -- and they want desperately to avoid the part of the brain that controls vision, which is very close to this region, and part of the brain that controls strength or power," Lang says. After a few hours of mapping and localizing the area, the surgeon then delivers electrical current to destroy brain cells in the sensorimotor territory of globus pallidus. "This part of the brain, in simplistic terms, serves as a brake to movement," Lang says. "So if you've got a brake on excessively, you don't move normally." Slow movements and rigidity are key features in Parkinson's disease. Thirty-nine patients in the two-year study were evaluated before and after surgery when they were taking L-dopa and when they were off the drug. After surgery while patients were off the medication, the researchers found a 28% reduction in the stiffness, tremors, and slowness of movement typical of the disease. They also observed a 29% increase in the ability to perform activities of daily living such as feeding and dressing. "Approximately half the patients who had been dependent on assistance in activities of daily living... before surgery became independent after surgery," the researchers note. Benefits of surgery were also noted when patients were on medication. "Involuntary movements that the drugs cause are much improved, both on the side opposite to the surgery and, interestingly, on the side of the surgery," Lang says. Thus, "they changed from a state where they required help to a state where they no longer required help" with certain activities of daily living," the researcher adds. Specifically, the researchers found an 82% reduction in dyskinesias on the side of the body opposite the side of the brain operated on when patients were on their medication again. However, not all surgery benefits were long-lived. Improvements in walking and stability lasted only six months, while the reduction in dyskinesias on the same side of the surgery were lost between one and two years of follow-up. "This information will help doctors decide who will benefit most from this procedure," Lang says. "For instance, a patient whose symptoms affect one side of the body more than the other will benefit greatly. But the patient who has exclusive walking problems and minimal L-dopa-induced dyskinesia would be a poor candidate for pallidotomy." By Leslie Lang SOURCE: The New England Journal of Medicine (1997;337:1036-1042) Copyright 1997 Reuters Limited. <http://www.reutershealth.com/news/rhdn/199710/1997100809.html> ------------------------------------------------------------------------ [log in to unmask]