title: Recurrent secondary generalization in frontal lobe epilepsy: Predictors and a potential link to surgical outcome?
abstract: OBJECTIVE
  Frontal lobe epilepsy (FLE) frequently leads to secondary generalized tonic-clonic seizures (SGTCS). However, little is known about the clinical, electrophysiologic, and radiologic correlates of SGTCS and whether these could influence diagnosis and treatment.
  
  
  METHODS
  A cohort of 48 patients with confirmed FLE was retrospectively identified and dichotomized into a group with and a group without SGTCS defined by history (≥1/year) or video-electroencephalography (vEEG). Demographics, seizure semiology, vEEG, neuroimaging data, and estimated seizure-onset zone were tabulated, and their association with the occurrence of SGTCS was evaluated with use of a chi-square test. Independent predictors of SGTCS were confirmed using a stepwise multivariate analysis. Similarly, these predictors as well as a history of SGTCS were tested as multivariate predictors of the postoperative International League Against Epilepsy (ILAE) score in the surgical subgroup (n = 25).
  
  
  RESULTS
  We identified three independent predictors of a history of SGTCS in FLE, including loss of responsiveness at seizure onset (corrected p = 0.04), a semiology involving early elementary motor signs (corrected p = 0.01), and multifocal spikes on EEG (corrected p = 0.02). A seizure-free outcome occurred in 57% of surgical cases and was more likely in the group without SGTCS (100%, p = 0.001). When considering only SGTCS occurring during video-EEG monitoring, the association with semiology and surgical outcome vanished, but the association with preserved awareness and a multifocal EEG persisted.
  
  
  CONCLUSIONS
  A history of SGTCS is related to a specific ictal semiology and interictal EEG, and may have a role in surgical risk stratification.
authors.affiliation: Department of Neurology, University of California San Francisco, San Francisco, California, U.S.A.
authors.forename: Maxime O
authors.initials: MO
authors.lastname: Baud
authors.affiliation: Epilepsy Center, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Serge
authors.initials: S
authors.lastname: Vulliemoz
authors.affiliation: Epilepsy Center, Geneva University Hospital, Geneva, Switzerland.
authors.forename: Margitta
authors.initials: M
authors.lastname: Seeck
mesh_terms: D000293:Adolescent; D000328:Adult; D015331:Cohort Studies; D004569:Electroencephalography; D017034:Epilepsy, Frontal Lobe / Q000601:surgery*; D005260:Female; D019788:Fluorodeoxyglucose F18; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D049268:Positron-Emission Tomography; D011237:Predictive Value of Tests; D012008:Recurrence; D012640:Seizures / Q000175:diagnosis*; D016896:Treatment Outcome; D055815:Young Adult
chemical_list: D019788:Fluorodeoxyglucose F18
keywords: Epilepsy imaging; Epilepsy surgery; Secondary generalized tonic-clonic seizure; Seizure semiology; Video-EEG