title: Surgical outcome and prognostic factors of frontal lobe epilepsy surgery.
abstract: Frontal lobe epilepsy (FLE) surgery is the second most common surgery performed to treat pharmacoresistant epilepsy. Yet, little is known about long-term seizure outcome following frontal lobectomy. The aim of this study is to investigate the trends in longitudinal outcome and identify potential prognostic indicators in a cohort of FLE patients investigated using modern diagnostic techniques. We reviewed 70 patients who underwent a frontal lobectomy between 1995 and 2003 (mean follow-up 4.1 +/- 3 years). Data were analysed using survival analysis and multivariate regression with Cox proportional hazard models. A favourable outcome was defined as complete seizure-freedom, allowing for auras and seizures restricted to the first post-operative week. The estimated probability of complete seizure-freedom was 55.7% [95% confidence interval (CI) = 50-62] at 1 post-operative year, 45.1% (95% CI = 39-51) at 3 years, and 30.1% (95% CI = 21-39) at 5 years. Eighty per cent of seizure recurrences occurred within the first 6 post-operative months. Late remissions and relapses occurred, but were rare. After multivariate analysis, the following variables retained their significance as independent predictors of seizure recurrence: MRI-negative malformation of cortical development as disease aetiology [risk ratio (RR) = 2.22, 95% CI = 1.40-3.47], any extrafrontal MRI abnormality (RR = 1.75, 95% CI = 1.12-2.69), generalized/non-localized ictal EEG patterns (RR = 1.83, 95% CI = 1.15-2.87), occurrence of acute post-operative seizures (RR = 2.17, 95% CI = 1.50-3.14) and incomplete surgical resection (RR = 2.56, 95% CI = 1.66-4.05) (log likelihood-ratio test P-value < 0.0001). More than half of patients in favourable prognostic categories were seizure-free at 3 years, and up to 40% were seizure-free at 5 years, compared to <15% in those with unfavourable outcome predictors. These data underscore the importance of appropriate selection of potential surgical candidates.
authors.affiliation: Department of Neurology, Section of Epilepsy, Cleveland Clinic, Cleveland, OH 44195, USA. jehil@ccf.org
authors.forename: Lara E
authors.initials: LE
authors.lastname: Jeha
authors.forename: Imad
authors.initials: I
authors.lastname: Najm
authors.forename: William
authors.initials: W
authors.lastname: Bingaman
authors.forename: Dudley
authors.initials: D
authors.lastname: Dinner
authors.forename: Peter
authors.initials: P
authors.lastname: Widdess-Walsh
authors.forename: Hans
authors.initials: H
authors.lastname: Lüders
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D002675:Child, Preschool; D004569:Electroencephalography; D004812:Epidemiologic Methods; D017034:Epilepsy, Frontal Lobe / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005625:Frontal Lobe / Q000601:surgery*; D006801:Humans; D007223:Infant; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D018579:Patient Selection; D049268:Positron-Emission Tomography; D011379:Prognosis; D012008:Recurrence; D016896:Treatment Outcome