"About 1.5 percent of the population suffers from epilepsy, and about 25 percent of patients do not respond to medication," said Dr. Bradley Vaughn, assistant professor of neurology at the UNC-CH School of Medicine. "We were part of a multicenter study involving 20 sites around the country that evaluated the implant device in more than 200 patients. We were very pleased with the results because this is going to be a useful tool for treating epilepsy."
About 30 percent of patients studied nationwide had a greater than 50 percent reduction in the number of seizures they suffered, Vaughn said. A few have become free of seizures since the device was implanted, and some who had the same number as before reported their seizures were shorter or less severe.
The battery-operated device, called a vagus nerve stimulator, is about the size and shape of a small compact for women's face powder or a pocket watch, Vaughn said. Surgeons bury it beneath the skin just below the left collarbone, and it is programmed to send electric current every few minutes through a wire that wraps around the vagus nerve in the neck. After extensive clinical trials, the U.S. Food and Drug Administration approved the stimulator July 16. Cyberonics Inc. manufactures it.
By studying the device's effect on the vagus nerve, the UNC-CH team was able to show no changes in patients' heart rates, or cardiac cycles. That revealed no impairment of the body's control of heart rate, which could be dangerous.
The team will present some of its findings next month at an American
Clinical Neurophysiology Society meeting in Los Angeles. A report on the
research also will appear in an upcoming issue of the journal Seizu
Contact: David L. Williamson
University of North Carolina at Chapel Hill