Breakthrough Epilepsy Therapy Prevents Seizures in Patients Without Other Options

January 8, 2018

A middle-age woman suffered with intractable, idiopathic epilepsy for decades. High doses of several antiepileptic drugs were ineffective, and she underwent three unsuccessful surgical procedures to treat her seizures at another facility. After a massive stroke, the patient remained with debilitating neurological deficits, including cognitive problems and language struggles; her seizures continued.

A common, chronic neurological disorder, epilepsy affects an estimated 3 million Americans and 50 million people, worldwide.1 Although a host of antiepileptic drugs have been introduced over the past decade, seizures in an estimated one-third of these patients cannot be controlled with medication. What’s more, the mortality rate among epilepsy patients is two-to-three times higher than the general population.1

“Individuals, such as this woman with medication-resistant epilepsy, who also fail conventional epilepsy surgery, now have other options, including neurostimulation,” said neurosurgeon Brian Snyder, MD, NYU Winthrop Hospital’s Director of Functional and Restorative Neurosurgery. “Options to reduce the brain’s potential to generate abnormal seizure activity include, vagus nerve stimulation and the latest break-through in the treatment of patients with uncontrolled seizures — responsive neurostimulation.”

The NeuroPace® Responsive Neurostimulator System (RNS)®, which recently received FDA approval, is the first closed-loop brain stimulation technology. The programmable, microprocessor-controlled device comprises implantable and external components, including an implanted neurostimulator, as well as detection and stimulation electrodes attached to the cortical surface or within deeper structures (e.g., hippocampus). The system is designed to identify and treat medically refractory, partial-onset seizures by detecting specific types of electrical activity in the brain through the electrodes placed near the patient’s seizure focus or foci. When detection thresholds are met, small, brief electrical charges aimed at terminating ictal discharges and reducing seizure frequency are delivered.

The system’s external components include a programmer, laptop computer with proprietary software and a wand; the programmer communicates with the implanted neurostimulator. “RNS continuously records the patient’s EEG, enabling us to download real-time data, detect abnormal brain activity and respond by delivering electrical stimulation to normalize brain activity before the patient experiences seizures,” explained Dr. Snyder. “The ongoing intracranial EEG recording helps us better localize the region of disease and safely treat once-untreatable patients whose foci were located in the eloquent cortex. This technology has the ability to stop the wave of seizure propagation. It is a treatment game changer.”

Use of RNS is restricted by the FDA to Comprehensive Epilepsy Centers — such as Winthrop’s — that meet the qualifications for the highest level of epilepsy care and have completed required training necessary to be able to implant the RNS System.

The patient who was suffering from unremitting seizures met all the criteria for the use of neurostimulation with RNS. She had several epileptogenic foci, was refractory to two or more antiepileptic medications and was experiencing frequent, disabling seizures. “Using advanced intracranial EEG monitoring, we were able to localize the epileptogenic areas and implant the RNS neurostimulator,” Dr. Snyder explained.

“Now, two months later, we have continuous EEG access to her brain activity. Her neurologist can download the data and refine the technology’s ability to interfere with the propagation of abnormal cell firings. She continues to be seizure-free, her cognitive problems have improved and her language difficulties have eased. She’s also more alert and definitely enjoying a better quality of life.”

1 Epilepsy Foundation