Mayo Clinic continues to examine neurostimulator device for epilepsy

Monday, March 19, 2007

JACKSONVILLE, Fla. — Neurologists at Mayo Clinic in Jacksonville, Fla., are enrolling patients with epilepsy in the next phase of a clinical research trial to further determine the safety and efficacy of a surgically implanted device that detects seizure activity in the brain and may suppress seizures before they start.

The device, called a responsive neurotransmitter (RNS), acts like a pacemaker for the brain. It may be implanted in some patients with frequent, disabling seizures who have failed treatment with at least two anti-epileptic medications. A treatment team works with patients who wish to be part of this research trial, called the RNS System Pivotal Clinical Investigation, to determine eligibility.

A Mayo Clinic neurosurgeon implants the self-contained device, not much bigger than a watch, under the scalp of eligible patients. The neurosurgeon then connects the responsive neurostimulator to wires placed in the region or regions of the brain where seizure activity occurs. The neurostimulator constantly monitors the brain's electrical activity for onset of seizure activity. When seizure activity is detected, the neurostimulator delivers mild electrical stimulation through the wires in an attempt to stop the seizure before the patient experiences symptoms.

Dr. Jerry Shih, Director of the Comprehensive Epilepsy Clinic at Mayo is one of trial's co-principal investigators. "The RNS concept is a potentially revolutionary step in the treatment of epilepsy," Shih says. "Whereas previous treatments with medications or vagus nerve stimulation alter the brain environment so that it is harder for seizures to begin, the RNS is the first potential epilepsy treatment to detect and abort seizures before the abnormal electrical activity can spread to other brain regions."

The Mayo treatment team will follow participants for at least two years after the device is implanted. Each month the team will assess the patient's seizure type and frequency and regularly asses each patient's physical and emotional health.

RNS is still considered an investigational treatment. Some patients may experience adverse reactions to the device, some may not experience fewer seizures and, as with any surgical procedure, there are associated risks.

Epilepsy is a chronic disorder of the brain that causes recurrent seizures and affects nearly 3 million people in the United States. Anti-epileptic medication can leave most patients free from seizures or lessen their frequency and intensity. Those who do not respond to medications may be candidates for surgical removal of the brain tissue responsible for triggering the seizure. In most cases, these patients still require medication to control seizures. The neurostimulator would eliminate the need to remove brain tissue from these patients.

This trial is sponsored by NeuroPace, Inc. Mayo Clinic Jacksonville researchers and patients participated in the previous phase of this trial. Mayo Clinic in Jacksonville is one of about 28 medical centers conducting this next phase.

Those interested in participating will need to undergo a comprehensive Mayo Clinic epilepsy evaluation before being considered as a candidate for this study. For an appointment, call (904) 953-6847.

# # #

To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news2007-jax. MayoClinic.com (www.mayoclinic.com) is available as a resource for your health stories.

###

To obtain the latest news releases from Mayo Clinic, go to www.mayoclinic.org/news. MayoClinic.com is available as a resource for your health stories.