Vagus nerve stimulation: clinical experience in drug-resistant pediatric epileptic patients

Abstract

Introduction: Vagus nerve stimulation (VNS) is an effective alternative treatment for patients with partial refractory epilepsy. Nevertheless, information regarding VNS in children is still limited.

Materials and methods: The clinical efficacy, safety and neuropsychological effects of VNS in 34 children (mean age 11.5 years) with drug-resistant epilepsy were studied. Mean follow-up was 30.8 months. Nine patients have been diagnosed with Lennox-Gastaut Syndrome, nine patients were affected by severe partial epilepsy with bisynchronous EEG and drop attacks, and 16 patients suffered from partial epilepsy without bisynchronous EEG and fall seizures. Forms were designed for prospective data collection on each patient's history, seizures, implants, device settings, quality of life (QOL), neuropsychological assessment and adverse events. Surgical technique was performed both by standard two incisions and single neck incision.

Results: Mean reduction in total seizures was 39% at 3 months, 38% at 6 months, 49% at 12 months, 61% at 24 months and 71% at 36 months. Significant better results were obtained in partial epilepsy, with and without drop attacks, than in Lennox-Gastaut syndrome--three patients being seizure-free. No operative morbidity was reported. Side-effects were minor and transient--the most common were voice alteration and coughing during stimulation. In two patients, electrode breakage occurred 3 years after surgical procedure; in both cases, a new device was implanted after removing the vagal electrode coils and generator.

Conclusion: VNS can be considered an appropriate strategy as an add-on treatment in children affected by drug-resistant partial epilepsy and ineligible for resective epilepsy surgery.