title: Epilepsy surgery outcomes in temporal lobe epilepsy with a normal MRI.
abstract: OBJECTIVE
  To determine the long-term efficacy of anterior temporal lobectomy for medically refractory temporal lobe epilepsy in patients with nonlesional magnetic resonance imaging (MRI).
  
  
  METHODS
  We identified a retrospective cohort of 44 patients with a nonlesional modern "seizure protocol" MRI who underwent anterior temporal lobectomy for treatment of medically refractory partial epilepsy. Postoperative seizure freedom was determined by Kaplan-Meyer survival analysis. Noninvasive preoperative diagnostic factors potentially associated with excellent surgical outcome were examined by univariate analysis in the 40 patients with follow-up of >1 year.
  
  
  RESULTS
  Engel class I outcomes (free of disabling seizures) were observed in 60% (24 of 40) patients. Preoperative factors associated with Engel class I outcome were: (1) absence of contralateral or extratemporal interictal epileptiform discharges, (2) subtraction ictal single photon emission computed tomography (SPECT) Coregistered to MRI (SISCOM) abnormality localized to the resection site, and (3) subtle nonspecific MRI findings in the mesial temporal lobe concordant to the resection.
  
  
  CONCLUSIONS
  In carefully selected patients with temporal lobe epilepsy and a nonlesional MRI, anterior temporal lobectomy can often render patients free of disabling seizures. This favorable rate of surgical success is likely due to the detection of concordant abnormalities that indicate unilateral temporal lobe epilepsy in patients with nonlesional MRI.
authors.affiliation: Department of Neurology and Division of Epilepsy and Electroencephalography, Mayo Clinic, Rochester, Minnesota 55905, USA.
authors.forename: Michael L
authors.initials: ML
authors.lastname: Bell
authors.forename: Satish
authors.initials: S
authors.lastname: Rao
authors.forename: Elson L
authors.initials: EL
authors.lastname: So
authors.forename: Max
authors.initials: M
authors.lastname: Trenerry
authors.forename: Noojan
authors.initials: N
authors.lastname: Kazemi
authors.forename: S Matt
authors.initials: SM
authors.lastname: Stead
authors.forename: Gregory
authors.initials: G
authors.lastname: Cascino
authors.forename: Richard
authors.initials: R
authors.lastname: Marsh
authors.forename: Fredric B
authors.initials: FB
authors.lastname: Meyer
authors.forename: Robert E
authors.initials: RE
authors.lastname: Watson
authors.forename: Caterina
authors.initials: C
authors.lastname: Giannini
authors.forename: Gregory A
authors.initials: GA
authors.lastname: Worrell
mesh_terms: D000293:Adolescent; D000328:Adult; D038481:Anterior Temporal Lobectomy / Q000379:methods*; D004567:Electrodes, Implanted; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000706:statistics & numerical data*; D008297:Male; D009483:Neuropsychological Tests; D017063:Outcome Assessment, Health Care; D011300:Preoperative Care; D011379:Prognosis; D012189:Retrospective Studies; D016019:Survival Analysis; D013702:Temporal Lobe / Q000601:surgery; D016896:Treatment Outcome
chemical_list: D019788:Fluorodeoxyglucose F18