title: Predictors of outcome in the surgical treatment for epilepsy.
abstract: BACKGROUND
  Knowledge about factors influencing the prognosis of resective epilepsy surgery can be used to identify which patients are most suitable for surgical treatment. The aim of this study was to identify preoperative prognostic factors associated with the chance of achieving long-term seizure freedom.
  
  
  METHODS
  We retrospectively reviewed seizure outcomes and clinical, electroencephalography (EEG), magnetic resonance imaging (MRI), histopathology, and surgical variables from 99 epilepsy surgery patients with at least one year of postoperative follow-up. Seizure outcomes were categorized based on the modified classification by the International League Against Epilepsy.
  
  
  RESULTS
  We found that the seizure-free rate was 27.9% after one year, and that it stabilized at about 20.0% between two and six years after surgery. Univariate analysis showed that medial temporal lobe epilepsy with hippocampal sclerosis, MRI with visible focal lesions concordant with EEG, and regional ictal EEG and electrocorticography patterns were associated with a favorable surgical outcome. On the other hand, seizure recurrence within six months, incomplete focus resection, and surgical complications were associated with a poor outcome. Multivariate analysis showed that medial temporal lobe epilepsy with hippocampal sclerosis and MRI with visible focal lesions were independent presurgical predictors of a favorable outcome (P < 0.01). Seizure recurrence within six months was the only significant independent predictor associated with a poor outcome (P < 0.01).
  
  
  CONCLUSIONS
  Hippocampal sclerosis and abnormal MRI findings are strongly associated with a favorable surgical outcome, whereas seizure recurrence within six months is associated with a poor outcome.
authors.affiliation: Department of Neurology, Renji Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200127, China.
authors.forename: Xiao-Lan
authors.initials: XL
authors.lastname: Yang
authors.forename: Qin-Chi
authors.initials: QC
authors.lastname: Lu
authors.forename: Ji-Wen
authors.initials: JW
authors.lastname: Xu
authors.forename: Gui-Song
authors.initials: GS
authors.lastname: Wang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Liu
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D004827:Epilepsy / Q000601:surgery*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012189:Retrospective Studies; D016896:Treatment Outcome; D055815:Young Adult