Chicago-New electronic techniques provide experimental new treatments for epilepsy, according to epilepsy expert Dr. Michael C. Smith. Smith spoke today at an American Medical Association media briefing on advances in neurology in New York.

Nine new medications for epilepsy have been introduced in the last 10 years, greatly improving the physician’s armamentarium against the disease according to Smith, director of the Epilepsy Center at Rush University Medical Center in Chicago. But there remains a large population of patients with hard-to-control epilepsy. Medical centers have begun recruiting patients for two new FDA-approved trials of direct electrical stimulation of the brain designed to control seizures in patients whose epilepsy can’t be controlled with medication.

For these patients, vagal nerve stimulation has been another option. In vagal nerve stimulation, a pulse generator, similar to a heart pacemaker, is linked via an under-the-skin cable to an electrode inserted into an opening at the side of the neck. This electrode is then fitted around the vagal nerve in the neck, one of the many nerves that carry messages to and from the brain.

The new trial treatments take advantage of technical innovations in miniaturization and computer technology to place electrodes directly into the brain. "These electrodes actually act much like the heart defibrillator implanted in Vice President Dick Cheney—keeping the heart beating in a normal rhythm and shocking it when it goes out of sync," said Dr. Smith. "While the rhythm of the brain is much more complicated than a heart beat, we have become very sophisticated in our ability to read complicated EEG [electroencephalogram – a graphic representation of the electrical activity in the brain] patterns, distinguishing normal brain rhythms from the abnormal rhythms of a seizure."

"In perhaps the most technically exciting trial, the area in the brain where the seizures originate is identified and both recording and stimulating electrodes are then implanted," explained Smith. "These electrodes are connected to a computer chip that can actually read the EEG, recognize the beginning of a seizure and then send a shock that will restore the normal brain rhythm. The computer chip and battery together approach the size of a hearing aid and are implanted behind the ear."

Physicians are often able to determine the location in the brain where seizures originate using EEGs, improved neuro-imaging and clinical signs, according to Smith. "For example, I had a patient who always heard an advertising jingle before the seizure. It turned out the seizures were occurring in a portion of the brain responsible for hearing," he said.

But some patients have hard-to-identify seizure centers or have multi-focal epilepsy with seizures originating in several areas. "In the other new trial, stimulation of the brain will be delivered to a ‘relay station’ in the brain, the thalamus, where, it is hoped, it will be able to keep brain rhythms normal by delivering pulsed, on and off, brief stimulation, much like a heart pacemaker," said Smith.

"It’s very important to continue to look for more and better treatments for epilepsy," said Smith. "One percent of the population of the United States, or 2.8 million people, have epilepsy now and 30 to 40 percent of those (840,000 to 1.2 million) have hard-to-control epilepsy."

"These targeted electronic therapies may prove very valuable. Medications that affect the brain are particularly likely to have unwanted side-effects," said Smith. "With electronic stimulation, we aren’t affecting the whole brain all the time, as we may be with medications. And, because the brain can not feel electronic stimulation, it is likely to be very well-tolerated."