title: Efficacy of vagus nerve stimulation in posttraumatic versus nontraumatic epilepsy.
abstract: OBJECTIVE
  In the US, approximately 500,000 individuals are hospitalized yearly for traumatic brain injury (TBI), and posttraumatic epilepsy (PTE) is a common sequela of TBI. Improved treatment strategies for PTE are critically needed, as patients with the disorder are often resistant to antiepileptic medications and are poor candidates for definitive resection. Vagus nerve stimulation (VNS) is an adjunctive treatment for medically refractory epilepsy that results in a ≥ 50% reduction in seizure frequency in approximately 50% of patients after 1 year of therapy. The role of VNS in PTE has been poorly studied. The aim of this study was to determine whether patients with PTE attain more favorable seizure outcomes than individuals with nontraumatic epilepsy etiologies.
  
  
  METHODS
  Using a case-control study design, the authors retrospectively compared seizure outcomes after VNS therapy in patients with PTE versus those with nontraumatic epilepsy (non-PTE) who were part of a large prospectively collected patient registry.
  
  
  RESULTS
  After VNS therapy, patients with PTE demonstrated a greater reduction in seizure frequency (50% fewer seizures at the 3-month follow-up; 73% fewer seizures at 24 months) than patients with non-PTE (46% fewer seizures at 3 months; 57% fewer seizures at 24 months). Overall, patients with PTE had a 78% rate of clinical response to VNS therapy at 24 months (that is, ≥ 50% reduction in seizure frequency) as compared with a 61% response rate among patients with non-PTE (OR 1.32, 95% CI 1.07-1.61), leading to improved outcomes according to the Engel classification (p < 0.0001, Cochran-Mantel-Haenszel statistic).
  
  
  CONCLUSIONS
  Vagus nerve stimulation should be considered in patients with medically refractory PTE who are not good candidates for resection. A controlled prospective trial is necessary to further examine seizure outcomes as well as neuropsychological outcomes after VNS therapy in patients with intractable PTE.
authors.affiliation: Comprehensive Epilepsy Center, University of California, San Francisco, California 94143-0112, USA. EnglotDJ@neurosurg.ucsf.edu
authors.forename: Dario J
authors.initials: DJ
authors.lastname: Englot
authors.forename: John D
authors.initials: JD
authors.lastname: Rolston
authors.forename: Doris D
authors.initials: DD
authors.lastname: Wang
authors.forename: Kevin H
authors.initials: KH
authors.lastname: Hassnain
authors.forename: Charles M
authors.initials: CM
authors.lastname: Gordon
authors.forename: Edward F
authors.initials: EF
authors.lastname: Chang
mesh_terms: D000293:Adolescent; D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use; D001930:Brain Injuries / Q000150:complications*; D016022:Case-Control Studies; D003131:Combined Modality Therapy; D003625:Data Collection; D004567:Electrodes, Implanted; D004827:Epilepsy / Q000209:etiology* / Q000628:therapy*; D005260:Female; D006801:Humans; D008297:Male; D012042:Registries; D012189:Retrospective Studies; D012640:Seizures / Q000453:epidemiology; D012959:Socioeconomic Factors; D016896:Treatment Outcome; D055536:Vagus Nerve Stimulation; D055815:Young Adult
chemical_list: D000927:Anticonvulsants