Vagus Nerve Stimulation for Intractable Seizures: One Year Follow-Up

Abstract

Even with the best health care available, many patients with epilepsy still suffer from poorly controlled seizures. Patients with intractable partial seizures are often inhibited from realizing their full potential and may experience a less than optimal quality of life. Vagus nerve stimulation (VNS) is being studied in a double-blind, controlled, randomized trial at 17 epilepsy centers throughout the U.S. and Europe as a potential therapy for patients with refractory seizures. During a 14-week controlled phase in three of the centers, the therapeutic group (N = 10) experienced a mean seizure frequency percent reduction (SFPR) of 33.1% as compared to baseline (p = 0.0084) while the subtherapeutic group (N = 12) experienced an SFPR of 0.6% as compared to baseline (p = 0.9183). After the controlled phase, all patients were switched into the therapeutic group in an open extension phase. Results after one year of therapeutic stimulation (N = 15) reveal a mean SFPR of 35.6% (p = 0.0088) with 6 of the 15 patients (40%) achieving at least a 50% seizure reduction. Adverse effects included hoarseness, coughing and nausea. There were no deaths or serious injuries related to the device. Based on these limited data, VNS appears to be a safe and efficacious new therapy for refractory partial seizures.