title: Surgical Treatment of Nonlesional Neocortical Epilepsy: Long-term Longitudinal Study.
abstract: The proportion of surgery for nonlesional neocortical epilepsy has recently increased, with a decrease in surgery for mesial temporal lobe epilepsy. However, there are only a few studies regarding the long-term surgical outcome and the potential prognostic factors for patients with nonlesional neocortical epilepsy.
  
  
  
  To evaluate the long-term surgical outcome and to identify possible prognostic factors in patients with nonlesional neocortical epilepsy.
  
  
  
  In a surgical cohort from September 1995 to December 2005 at the Seoul National University Hospital, we included 109 consecutive patients without lesions identifiable by magnetic resonance imaging who underwent focal surgical resection for drug-resistant neocortical epilepsy. Follow-up information for at least 10 years was available for all but 1 patient.
  
  
  
  Univariate and standard multiple logistic regression analyses were performed to identify the predictors of surgical outcomes, and a generalized estimation equation model was used for the longitudinal multiple logistic regression analysis of up to 21 years of follow-up.
  
  
  
  The patients consisted of 64 men and 45 women with ages at surgery ranging from 7 to 56 years (mean [SD], 27.1 [7.8] years). At 1 year after surgery, 59 of 109 patients (54.1%) achieved seizure freedom, and 64 of 108 patients (59.3%) achieved seizure freedom at the last follow-up. Only 11 of 108 patients (10.2%) experienced definite changes in postoperative seizure status. Localizing patterns in functional neuroimaging (strongest odds ratio [OR], 0.30 [95% CI, 0.14-0.66] for fluorodeoxyglucose-positron emission tomography; 0.37 [95% CI, 0.15-0.87] for ictal single-photon emission computed tomography), concordant results in presurgical diagnostic evaluations (OR, 3.15 [95% CI, 1.42-7.02]), the presence of aura (OR, 3.49 [95% CI, 1.54-7.92]), and complete resection of areas of ictal onset with frequent interictal spikes during the intracranial electroencephalographic study (OR, 0.37 [95% CI, 0.16-0.85]) were favorable surgical outcome predictors.
  
  
  
  Our study showed that nearly 60% of patients with nonlesional neocortical epilepsy achieved freedom from long-term seizure, and that changes in postoperative seizure status were rarely observed. Several predictors of favorable surgical outcomes were identified, which can help select optimal candidates for surgical treatment among patients with nonlesional neocortical epilepsy.
authors.affiliation: Department of Neurology, Konkuk University School of Medicine, Seoul, Korea.
authors.forename: Dong Wook
authors.initials: DW
authors.lastname: Kim
authors.affiliation: Department of Neurology, College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Sang Kun
authors.initials: SK
authors.lastname: Lee
authors.affiliation: Department of Neurology, Dongsan Medical Center, Keimyung University School of Medicine, Daegu, Korea.
authors.forename: Hye-Jin
authors.initials: HJ
authors.lastname: Moon
authors.affiliation: Department of Neurology, College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Ki-Young
authors.initials: KY
authors.lastname: Jung
authors.affiliation: Department of Neurology, College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Kon
authors.initials: K
authors.lastname: Chu
authors.affiliation: Department of Neurosurgery, College of Medicine, Seoul National University Hospital, Seoul, Korea.
authors.forename: Chun-Ki
authors.initials: CK
authors.lastname: Chung
mesh_terms: D000293:Adolescent; D000328:Adult; D002648:Child; D015331:Cohort Studies; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D019579:Neocortex / Q000000981:diagnostic imaging / Q000473:pathology*; D019635:Neurosurgical Procedures / Q000379:methods*; D049268:Positron-Emission Tomography; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18