Vagal nerve stimulation for refractory epilepsy: Eight years of experience on 183 Iraqi patients

Abstract

Background: Vagus nerve stimulation has been broadly known as one of treatment lines for refractory epilepsy, especially in poor applicants for resection surgeries or in whom resection has failed. Its use for different seizure-types control is increasing. Aims: We aimed to assess the efficacy of Vagal nerve stimulation (VNS) therapy outcome predictive aspects utilizing subgroup analysis. Materials and Methods: From 2008 until 2016, 183/190 refractory epilepsy cases with specific inclusion criteria were selected. All underwent pre- and postimplantation assessment of response utilizing Engel criteria and Chalfont seizure severity scoring system for 2 years. Descriptive and statistical data analysis was accomplished for the data of age at epilepsy start and VNS insertion, seizures nature, device stimulation parameters, and peri-surgical antiepileptic medicines. Results: At 12 months follow-up period (29.5%), patients were assigned to a Class I and II outcome (representing very good seizure outcome) especially among patients with G. T. C seizure. 38.8% had a “worthwhile” improvement and consigned as Class III outcome mostly among P. S. G patients. The response was better at 24 months' follow-up period. Patients <10 years of age with pre surgery mean duration of epilepsy of 10 (+5) years and mean age at onset of epilepsy of 7 (+5) years showed better response. Mean seizure frequency reduction was 69.8% (+18). Conclusions: Stimulation parameters needed was lower for class I and II with significant reduction of required anti-epileptic drugs (AED). Our study may help to provide response predictive characteristics.