New Device Reduces Seizures in Epilepsy by 50%

The FDA recently approved a new implantable neurostimulation device shown to reduce seizures in patients with medication-resistant epilepsy by as much as 50%.

Now physicians at Rush Epilepsy Center in Chicago suggest that this device—the NeuroPace RNS System—could help to completely eliminate seizures when paired with an electrode-placement planning system they developed.
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They succeeded in completely eliminating seizures in almost half of the Rush patients who had been enrolled in decade-long clinical trials of the device. “This device will benefit a significant portion of the approximately 400,000 to 500,000 patients with medication-resistant epilepsy, who were not previously considered epilepsy brain surgery candidates,” says Marvin A. Rossi, MD, PhD, co-principal investigator of the NeuroPace Pivotal Clinical Trial and assistant professor of neurology at the Rush Epilepsy Center.

It is the first responsive or ‘on-demand’ device that delivers direct cortical stimulation therapy to receive FDA approval for the adjunctive treatment of medication-resistant focal-onset epilepsy.

Surgically implanted within the skull, the device connects to electrodes strategically placed within the brain where the seizures originate. The system detects abnormal electrical activity in the brain and delivers small amounts of electrical stimulation to suppress seizures before they begin.

The device can also record EEG segments of the seizures and send the information to a HIPAA-compliant central computer database at NeuroPace. Treating physicians can then log in and identify seizure frequency, location of seizures, and their timing.

“Patient diaries are notoriously inaccurate,” Rossi says. “Now a system exists for remotely providing a more objective method of measuring seizure frequency, duration, and even brain location of seizure onset, as well as stimulator settings.”

“One can even use this system for chronic brain monitoring to potentially take the patient to brain resection after many months or years of intracranial EEG monitoring to potentially further improve seizure control,” he says.

Post-approval FDA criteria recommend that candidate patients experience at least 3 disabling seizures per month. “Those patients with 1 or 2 identifiable seizure sources or foci located in the temporal lobes of the cerebral cortex were best suited for the RNS, and demonstrated the best outcomes when compared to those with seizure foci in cortical regions located outside of the temporal lobe,” Rossi says.

The seizures also must last long enough for the device to identify the seizure-onset signature and deliver electrical current; therefore, Rossi says patients who experience sudden-onset drop (atonic) seizures, or brief tonic or myoclonic seizures are typically not candidates.

Clinical trials indicated that risks of the NeuroPace RNS (i.e., brain hemorrhage, infection, skin erosion) were significantly lower than those seen with a deep brain stimulator used to treat movement disorders.

At this time, Rossi says it is expected that Medicare and many private insurers will reimburse for the device; however, its costs are significant. “In the end, the cost to the health care system will be the determining factor,” he says. “For example, during the clinical trials, some of the participating centers observed a significant decrease in utilization of health care resources and readmissions for this very refractory patient population.”

—Colleen Mullarkey

Reference

Dilorenzo DJ, Mangubat EZ, Rossi MA, Byrne RW. Chronic unlimited recording electrocorticography-guided resective epilepsy surgery: technology-enabled enhanced fidelity in seizure focus localization with improved surgical efficacy. J Neurosurg. 2014 Mar 21. [Epub ahead of print].