Vagus Nerve Stimulation as a Treatment for Refractory Epilepsy: A 15-Year Experience in an Italian Tertiary – Care Epilepsy Center

Chiara      Pizzanelli; Renato      Galli; Filippo      S. Giorgi; Alfonso      Iudice; Enrica      Bonanni; Veronica      Pelliccia; Stella      Jensen; Laura      Manca; Bruno      Lenzi; Ludovico      Lutzemberger; Giuliano      Parenti; Francesco      Fornai; Luigi      Murri

Abstract

Purpose: Vagus Nerve Stimulation (VNS) is indicated in the treatment of pharmacoresistant epilepsy. Albeit its general efficacy, the use of VNS remains undefined concerning two points: i) there are only a few long-term studies, none randomized; ii) there are no clinical markers which allow to predict VNS response. In order to explore these points, we report the long-term outcomes of VNS in 22 patients.

Methods: Twenty-two patients with refractory epilepsy, either symptomatic generalized or cryptogenic/symptomatic partial were treated with VNS and monitored up to 15 years (6.5±1.1).

Results: No significant adverse events were observed. VNS efficacy was enduring and increased significantly over time. Seizure frequency decreased by 34.3±3.9% after 1 year, 40.3±4.6% after 2 years, 48.0±5.4% after 3 years, 53.4±7.9% after 5 years and 48.1%±5.8 at maximum follow up. Data on syndrome-specificity were not significant (small number of patients in each group).

Conclusions: This study confirms sustained efficacy of VNS in epilepsy. Generalized symptomatic and temporal lobe epilepsy seem to be associated to a better outcome to VNS, but additional data are required.

Keywords: Alternative therapy, Epilepsy, Long-term study, Neurosurgery, Pharmacoresistance, Vagus nerve stimulation, Neurological Disorder, Antilepitic Drugs, Antilepitic effect, Rationale, Dosing, Epileptic Patient, Aetiologies, Epileptic Seizures, Lennox Gastaut syndrome lepsy