In a randomized, double-blind, multicenter trial, researchers are studying the effect of the Responsive Neurostimulator System (RNS) to help patients with uncontrolled epilepsy. Through electrodes implanted in the brain, the device detects seizure activity and delivers stimulation via a low-level electric current to stop it.

The device is placed within the skull and connected by leads to two electrodes implanted in the brain where the main seizure activity occurs. The device continuously monitors the brain's electrical activity. When the device senses electrical activity that signals the start of a seizure, it sends electrical stimulation through the leads to the seizure focus to suppress the seizure. It delivers stimulation to the brain only after sensing seizure activity.

An earlier study of the RNS in 65 adults with uncontrolled epilepsy indicated that the device is safe. The current trial aims to determine if the device is effective in adults with partial-onset seizures refractory to treatment with two or more antiepileptic drugs.

Usually treated with antiepileptic drugs, epilepsy is poorly controlled in 30% to 40% of more than 2 million people in the United States with the condition.

For more information on the device, visit the manufacturer's Web site at http://www.neuropace.com/.