Stopping seizures

A small electronic device implanted in the skull that detects oncoming seizures then delivers a brief electrical stimulus to the brain to stop them is under study at the Medical College of Georgia (MCG).

MCG is among some dozen US centres participating in a study to determine if the neurostimulator device can help patients whose seizures are not well controlled by drugs.

“We really want another option for treating patients who are not effectively helped by existing treatments,” says Dr. Anthony Murro, neurologist, epileptologist and a principal investigator on the study.

“If this works out, it could represent a new way of treating epilepsy that is unlike drug treatment where people live with the side effects of drugs they take every day to prevent seizures.”

“If this works as well as we hope it works, it could absolutely revolutionize epilepsy surgery,” says Dr. Joseph Smith, MCG neurosurgeon specializing in stereotactic and functional surgery. Dr. Smith, who has performed epilepsy surgery at MCG Medical Center since 1985, says if the study proves the device is effective, he can see patients preferring the new approach to today’s standard that often includes removing areas of the brain where abnormal electrical activity originates, called the seizure focus.

At MCG Medical Center, the device will be used in about 20 patients aged between 18-65 who have not gotten their seizures controlled on at least two medications and have at least four seizures per month; seizure activity is closely monitored through a diary and monthly doctor visits for three months before patients are eligible.

“We use the patient’s seizure pattern which we record before surgery to develop the parameters we use to detect future seizures,” Dr. Smith says.

During the medical procedure, the device itself is placed inside the skull accompanied by two electrodes that are placed within the brain near the seizure focus. Afterward, a modified laptop computer is used to look at electrical activity picked up by the neurostimulator and to program the device to recognize the patient’s seizure activity.

Then if the neurostimulator detects abnormal activity, it sends an electrical stimulus to stop it, a stimulus that appears to go unnoticed by patients, the doctors say.

Study patients will be followed for about two years to assess how well the device works.

Doctors already have experience using electrical activity to help control seizures. A pacemaker-like device called the vagus nerve stimulator has been used for about six years that regularly electrically stimulates the vagal nerve in the neck, sending signals to the brain.

The vagus nerve stimulator has helped reduce seizure frequency but is unlikely to make many patients seizure-free.

“If they still have a seizure, even just one every several months, most patients still have trouble driving, getting and keeping a job and living a normal life,” Dr. Murro says. “So the goal is to stop all seizures.”