title: Independent predictors and a prognostic model for surgical outcome in refractory frontal lobe epilepsy.
abstract: OBJECTIVE
  Refractory frontal lobe epilepsy (FLE) remains one of the most challenging surgically remediable epilepsy syndromes. Nevertheless, definition of independent predictors and predictive models of postsurgical seizure outcome remains poorly explored in FLE.
  
  
  METHODS
  We retrospectively analyzed data from 70 consecutive patients with refractory FLE submitted to surgical treatment at our center from July 1994 to December 2006. Univariate results were submitted to logistic regression models and Cox proportional hazards regression to identify isolated risk factors for poor surgical results and to construct predictive models for surgical outcome in FLE.
  
  
  RESULTS
  From 70 patients submitted to surgery, 45 patients (64%) had favorable outcome and 37 (47%) became seizure free. Isolated risk factors for poor surgical outcome are expressed in hazard ratio (H.R.) and were time of epilepsy (H.R.=4.2; 95% C.I.=1.5-11.7; p=0.006), ictal EEG recruiting rhythm (H.R.=2.9; 95% C.I.=1.1-7.7; p=0.033); normal MRI (H.R.=4.8; 95% C.I.=1.4-16.6; p=0.012), and MRI with lesion involving eloquent cortex (H.R.=3.8; 95% C.I.=1.2-12.0; p=0.021). Based on these variables and using a logistic regression model we constructed a model that correctly predicted long-term surgical outcome in up to 80% of patients.
  
  
  CONCLUSIONS
  Among independent risk factors for postsurgical seizure outcome, epilepsy duration is a potentially modifiable factor that could impact surgical outcome in FLE. Early diagnosis, presence of an MRI lesion not involving eloquent cortex, and ictal EEG without recruited rhythm independently predicted favorable outcome in this series.
authors: Ribeirão Preto Epilepsy Surgery Center, Department of Neuroscience and Behavioral Science, Ribeirão Preto School of Medicine, University of São Paulo, Ribeirao Preto, Brazil. anapaulamartins@usp.br
authors: Ana P
authors: AP
authors: Pinheiro-Martins
authors: Marino M
authors: MM
authors: Bianchin
authors: Tonicarlo R
authors: TR
authors: Velasco
authors: Vera C
authors: VC
authors: Terra
authors: David
authors: D
authors: Araújo
authors: Lauro
authors: L
authors: Wichert-Ana
authors: João A
authors: JA
authors: Assirati
authors: Hélio R
authors: HR
authors: Machado
authors: Carlos G
authors: CG
authors: Carlotti
authors: Américo C
authors: AC
authors: Sakamoto
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography / Q000379:methods; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis* / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D011379:Prognosis; D012189:Retrospective Studies; D016896:Treatment Outcome; D014741:Video Recording / Q000379:methods; D055815:Young Adult