Effect of vagus nerve stimulation on adults with pharmacoresistant generalized epilepsy syndromes

Abstract

Introduction: Although vagus nerve stimulation (VNS) therapy is approved for the treatment of partial onset seizures, its efficacy for generalized seizures has not been fully evaluated. This Investigational Device Exemption assessed the outcome of VNS therapy among patients with generalized epilepsy syndromes. Methods: Sixteen patients with pharmacoresistant generalized epilepsy syndromes and stable antiepileptic drug (AED) regimens were implanted with the VNS therapy device and were evaluated for changes in seizure frequency and type between baseline and follow-up of 12–21 months. Results: The patients experienced a statistically significant overall median seizure frequency reduction of 43.3% ( P=0.002, Wilcoxon signed rank test) after 12–21 months of VNS therapy. Types of seizures that may involve a fall or collapse decreased with reductions in the frequency of myoclonic (60% reduction, n=9; P=0.016, Wilcoxon signed rank test), tonic (75% reduction, n=8, NS), atonic (98.6%, n=3, NS), and clonic seizures (86.7%, n=1, NS). Conclusion: The benefits of reduced seizure frequency and reduced risk of injury merit consideration of VNS therapy for patients with pharmacoresistant generalized seizure syndromes.