Preliminary VNS Study Produces Encouraging Results

Of the millions of Americans suffering from clinical depression, experts estimate that more 20 percent experience no relief through existing pharmaceutical treatments. Those patients are left with an uncertain combination of drug, hormone and electroconvulsive treatments, said Francisco Moreno, M.D., assistant professor of psychiatry at the University of Arizona College of Medicine.

Vagus nerve stimulation, an effective epilepsy treatment, has produced encouraging preliminary results for patients suffering from "treatment-resistant depression", and a study beginning at University Medical Center (Univ. of Arizona) and a handful of other U.S. sites may verify the promising new therapy.

The study patients are implanted with a NeuroCybernetic Prosthesis (NCP) System, which consists of a battery-powered generator implanted in the chest and a lead attached, at neck level, to the vagus nerve leading to the brain. The device delivers an automatic, periodic electrical stimulation to the vegus nerve. A physician can adjust the intensity, duration and frequency of the stimulation, which may be minimally noticeable by the patient, in follow-up visits.

David Labiner, M.D., associate professor of neurology at the UA College of Medicine, was principal investigator of a UMC study of the NCP system's effectiveness in the treatment of epilepsy in 1994-95. The device received approval for general use in epilepsy treatment by the U.S. Food and Drug Administration in 1997.

"During the epilepsy study we noticed many patients felt better emotionally," Dr. Labiner said. "Even the patients who did not have a reduction in the number of seizures they were experiencing felt better." NCP therapy, produced by Cyberonics Inc. of Houston, already has completed an initial study of the depression treatment. The current study could be completed in the next two years at which time the FDA could approve the treatment for general use.

Source: Univ. of Arizona College of Medicine, Oct. 2000

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