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Date: Wednesday, July 16, 1997
FOR IMMEDIATE RELEASE 
FOOD AND DRUG ADMINISTRATION, Sharon Snider:(301) 443­3285, Broadcast Media: (301) 827­3434, Consumer Hotline: (800) 532­4440

FDA Approves Medical Device For Epilepsy

The approval came just 19 days after the positive recommendation of the Neurological Devices Panel of FDA's Medical Devices Advisory Committee. FDA received an application to market the product on Jan. 27 and expedited its review because of its potential importance for reducing seizures in people who lack effective, alternative treatment.

The device, called a vagus nerve stimulator, consists of a generator which is implanted under the collar bone like a pacemaker and connected by wire to the vagus nerve in the neck where it delivers electrical signals to the brain to control seizures. It includes an external programming system which is used by the physician to change stimulation settings. Patients can turn the stimulator on and off with a hand­held magnet by holding it over the stimulator.

The NeuroCybernetic Prosthesis System, made by Cyberonics, of Houston, was approved for use in conjunction with drugs or surgery in adults and adolescents with partial onset seizures, the type of seizures that begin in one part of the brain and may remain localized or become generalized to the entire brain.

"Vagus nerve stimulators offer people with uncontrolled seizures a new type of treatment," said Bruce Burlington, director of FDA's Center for Devices and Radiological Health. "While this device will not help everyone, it will reduce the frequency of seizures in many people."

Approximately 1.7 million Americans have epilepsy. Most seizures can be controlled by medication. However, about 200,000 people have seizures that cannot be fully or adequately controlled with drugs or surgery. Severe, ongoing seizures can lead to death.

FDA's approval of the device was based on a review of clinical studies on safety and effectiveness submitted by the manufacturer and on the recommendation of the Neurological Devices Panel.

In the studies, the device was implanted in 454 patients with poorly controlled seizures at 45 medical centers in the United States, Canada and Europe. The patients continued to take anti­seizure medication during the study.

In the most recent study, most patients showed at least some improvement with the vagus nerve stimulator. Half the patients treated had at least a 20 percent reduction in the number of seizures per day. In about 1 in 4, the frequency of seizures decreased by more than 50 percent. In about 1 in 5, however, the number of seizures actually increased.

Side effects during stimulation included cough (50%), hoarseness (100%), voice alteration (73%), and shortness of breath (25%).

However, these side effects were considered tolerable by most patients.

Nine patients died during the studies, but none of the deaths were believed by the clinical investigators to be caused by the device. Four deaths were classified as Sudden Unexpected Death in Epilepsy. The others resulted from drownings, pneumonia, liver failure and blood disease.

Although the death rate was not statistically higher than that expected for people with severe, poorly controlled seizures, FDA has asked Cyberonics to continue to provide detailed information about any further deaths, particularly any sudden unexpected deaths. The agency has also asked the company to further evaluate its study data to find out whether any factors predict which patients are the most likely and least likely to benefit from use of the device.