Neurostimulator Used for Treatment of Epilepsy in Research Trial

Epilepsy is a common neurological disorder affecting about 2.5 million people of all ages in the U.S. As many as half of patients with epilepsy continue to have seizures or medication-related side effects despite best medical efforts to control their seizures. Some patients are candidates for epilepsy surgery to remove the seizure focus, but some types of epilepsy are unlikely to respond to surgery or may be at high risk for surgery-related neurological complications. Implantable brain stimulation devices to treat epilepsy may offer hope to those who are not adequately treated by antiseizure medication and are not candidates for safe and effective resective surgery.

Yale University School of Medicine and Yale-New Haven Hospital are participating in a multi-center, FDA-approved feasibility clinical investigation of a responsive brain neurostimulator device for the treatment of epilepsy. The neurostimulator is designed to detect seizures in patients with epilepsy and to deliver mild electrical stimulation to suppress seizures before the patient has any symptoms.

The neurostimulator is surgically placed within the skull and connected to electrode wires implanted within the brain or resting on the brain surface in the area of the seizure focus. The neurostimulator continuously monitors brain electrical activity and, after identifying the “signature” of a seizure’s onset, the device delivers brief and mild electrical stimulation to suppress the seizure. Prior to surgery to implant the neurostimulator system, the patient’s seizure focus is localized by tests that may include EEG (electroencephalography) and MRI, as well as other forms of evaluation.

Previous testing of responsive stimulation to control epilepsy has been conducted on a short-term basis in patients being evaluated for epilepsy surgery with surgically implanted electrodes. This early experience indicated that localized electrical stimulation in response to seizure-like brain electrical activity appears safe and can suppress some abnormal electrical discharges. These studies were conducted as part of a separate multi-center study. Dennis Spencer, MD--one of two neurosurgeons specializing in surgery to treat epilepsy--explains, “This is clearly very early in the investigation and it is not clear who the device may help or whether the stimulation will stop all seizures. However, this study ushers in a new era in the treatment of medically refractory epilepsy. Although surgery has been very successful for many of these patients, the possibility of stimulation therapy expands our ability to help the most severely affected patients and may help without having to remove the piece of the brain responsible for the seizures.”

During surgery to place the neurostimulator, the surgeon makes a small opening in the skull and places the device in a tray-like holder that is fastened to the surrounding bone. After surgery, a patient does not feel the device in his or her head. Recovery in the hospital is about three days.

Following surgery, a participant in the trial visits his or her epileptologist, who uses a modified laptop computer known as a Programmer to read electrical activity and diagnostics recorded by the implanted neurostimulator. The epileptologist programs the neurostimulator to recognize the participant’s seizures and deliver responsive stimulation. There are scheduled follow-up visits with the neurologist throughout the research trial. Those participating in this trial will continue in the study for at least two years.

Persons eligible to participate in this study have

• Partial (focal) onset seizures that have not been controlled on at least two antiseizure medications
• And at least four seizures each month

For more information regarding epilepsy and epilepsy treatment at Yale, contact Diane Giglio RN, program coordinator for the Epilepsy Surgery Program at (203) 785-4891.

For further reference please visit some of the links below:

Spotlight on The Epilepsy Program at Yale

Neurologists caring for patients with epilepsy at Yale

Neurosurgeons caring for patients with epilepsy at Yale

The physicians at Yale in the Epilepsy Program and their profiles

More about Epilepsy

Click for more about Robert Duckrow, MD, Dennis Spencer, MD, Susan Spencer, MD, or Kenneth Vives, MD.