FDA Approves New Treatment for Epilepsy

For patients who do not respond to medical treatment, a newly approved device, the RNS Stimulator by Neuropace, Inc., offers hope. 

The US. Food and Drug Administration has approved a device to help reduce the frequency of seizures in patients with epilepsy who have not responded well to medications.

According to the Epilepsy Foundation, epilepsy affects nearly 3 million people in the United States and is the third most common neurological disorder, after Alzheimer’s disease and stroke. Epilepsy produces seizures affecting varied mental and physical functions. Seizures happen when clusters of nerve cells in the brain signal abnormally, which may briefly cause a person to lose consciousness, and have uncontrolled movements or actions. Approximately 40%  of people with epilepsy are severely affected and continue to have seizures despite treatment.

How it Works

The newly approved device, the RNS Stimulator by Neuropace, Inc. of Mountain View, California, consists of a small neurostimulator implanted within the skull under the scalp. The neurostimulator is connected to one or two wires (called electrodes) that are placed where the seizures are suspected to originate within the brain or on the surface of the brain.

“The neurostimulator detects abnormal electrical activity in the brain and responds by delivering electrical stimulation intended to normalize brain activity before the patient experiences seizure symptoms,” said Christy Foreman, director of the Office of Device Evaluation in the FDA’s Center for Devices and Radiological Health.

Approval Process

The FDA’s approval is supported by a study of 191 patients with drug-resistant epilepsy.

The study showed that by 3 months after the implanted device was turned on (active use) patients experienced a nearly 38% reduction in the average number of seizures per month, compared to an approximately 17% reduction in the average number of seizures per month in patients who had the implanted device turned off (placebo). At the end of 3 months, the median reduction in seizures, which reflects a more typical patient experience, was 34% with active device compared with about 19% with the device turned off. During the trial, 29% of patients with an active device experienced at least a 50% reduction in the overall number of seizures, compared to 27% for those with the implanted device turned off.

Two years after the end of the trial, patients continued to demonstrated a persistent reduction in seizure frequency.


According to the FDA, patients with the stimulators cannot undergo magnetic resonance imaging (MRI) procedures, nor can they undergo diathermy procedures, electroconvulsive therapy (ECT) or transcranial magnetic stimulation (TMS). The energy created from these procedures can be sent through the neurostimulator and cause permanent brain damage, even if the device is turned off.

The most frequent adverse events reported were implant site infection and premature battery depletion.


Updated on: 11/14/13