title: Vagal nerve stimulation for the treatment of medically refractory epilepsy: a review of the current literature.
abstract: OBJECTIVE
  The authors conducted a study to evaluate the published results of vagal nerve stimulation (VNS) for medically refractory seizures according to evidence-based criteria.
  
  
  METHODS
  The authors performed a review of available literature published between 1980 and 2010. Inclusion criteria for articles included more than 10 patients evaluated, average follow-up of 1 or more years, inclusion of medically refractory epilepsy, and consistent preoperative surgical evaluation. Articles were divided into 4 classes of evidence according to criteria established by the American Academy of Neurology.
  
  
  RESULTS
  A total of 70 publications were reviewed, of which 20 were selected for review based on inclusion and exclusion criteria. There were 2 articles that provided Class I evidence, 7 that met criteria for Class II evidence, and 11 that provided Class III evidence. The majority of evidence supports VNS usage in partial epilepsy with a seizure reduction of 50% or more in the majority of cases and freedom from seizure in 6%-27% of patients who responded to stimulation. High stimulation with a gradual increase in VNS stimulation over the first 6 weeks to 3 months postoperatively is well supported by Class I and II data. Predictors of positive response included absence of bilateral interictal epileptiform activity and cortical malformations.
  
  
  CONCLUSIONS
  Vagal nerve stimulation is a safe and effective alternative for adult and pediatric populations with epilepsy refractory to medical and other surgical management.
authors.affiliation: Department of Neurosurgery, Louisiana State University Health Sciences Center-Shreveport, Louisiana 71130-3932, USA.
authors.forename: David E
authors.initials: DE
authors.lastname: Connor
authors.forename: Menarvia
authors.initials: M
authors.lastname: Nixon
authors.forename: Anil
authors.initials: A
authors.lastname: Nanda
authors.forename: Bharat
authors.initials: B
authors.lastname: Guthikonda
mesh_terms: D001921:Brain / Q000502:physiology; D046690:Deep Brain Stimulation / Q000379:methods; D004827:Epilepsy / Q000628:therapy*; D006801:Humans; D016032:Randomized Controlled Trials as Topic; D014630:Vagus Nerve / Q000502:physiology*; D055536:Vagus Nerve Stimulation / Q000379:methods*