title: Predicting long-term seizure outcome after resective epilepsy surgery: the multicenter study.
abstract: BACKGROUND
  In a seven-center prospective observational study of resective epilepsy surgery, the authors examined probability and predictors of entering 2-year remission and the risk of subsequent relapse.
  
  
  METHODS
  Patients aged 12 years and over were enrolled at time of referral for epilepsy surgery, and underwent standardized evaluation, treatment, and follow-up procedures. The authors defined seizure remission as 2 years completely seizure-free after hospital discharge with or without auras, and relapse as any seizures after 2-year remission. The authors examined type of surgery, seizure, clinical and demographic variables, and localization study results with respect to prediction of seizure remission or relapse, using chi2 and proportional hazards analysis.
  
  
  RESULTS
  Of 396 operated patients, 339 were followed over 2 years, and 223 (66%) experienced 2-year remission, not significantly different between medial temporal (68%) and neocortical (50%) resections. In multivariable models, only absence of generalized tonic-clonic seizures and presence of hippocampal atrophy were significantly and independently associated with remission, and only in the medial temporal resection group. Fifty-five patients relapsed after 2-year remission, again not significantly different between medial temporal (25%) and neocortical (19%) resections. Only delay to remission predicted relapse, and only in medial temporal patients.
  
  
  CONCLUSIONS
  Hippocampal atrophy and a history of absence of generalized tonic clonic seizures were the sole predictors of 2-year remission, and only for medial temporal resections.
authors.affiliation: Department of Neurology, Yale University School of Medicine, New Haven, CT 06520-8018, USA. susan.spencer@yale.edu
authors.forename: S S
authors.initials: SS
authors.lastname: Spencer
authors.forename: A T
authors.initials: AT
authors.lastname: Berg
authors.forename: B G
authors.initials: BG
authors.lastname: Vickrey
authors.forename: M R
authors.initials: MR
authors.lastname: Sperling
authors.forename: C W
authors.initials: CW
authors.lastname: Bazil
authors.forename: S
authors.initials: S
authors.lastname: Shinnar
authors.forename: J T
authors.initials: JT
authors.lastname: Langfitt
authors.forename: T S
authors.initials: TS
authors.lastname: Walczak
authors.forename: S V
authors.initials: SV
authors.lastname: Pacia
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001284:Atrophy / Q000473:pathology / Q000503:physiopathology; D001921:Brain / Q000503:physiopathology* / Q000601:surgery*; D002648:Child; D015331:Cohort Studies; D004827:Epilepsy / Q000503:physiopathology / Q000517:prevention & control* / Q000601:surgery*; D006624:Hippocampus / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D006801:Humans; D008875:Middle Aged; D019579:Neocortex / Q000473:pathology / Q000503:physiopathology / Q000601:surgery; D019635:Neurosurgical Procedures / Q000706:statistics & numerical data*; D011379:Prognosis; D011446:Prospective Studies; D055502:Secondary Prevention; D012640:Seizures / Q000453:epidemiology / Q000503:physiopathology; D016896:Treatment Outcome