title: Outcome of temporal lobe epilepsy surgery evaluated with bitemporal intracranial electrode recordings.
abstract: Temporal lobe epilepsy (TLE) with unclear lateralization may require intracranial implantation of electrodes (IIE). We retrospectively assessed the association between the use of IIE and long-term outcomes in patients undergoing anterior temporal lobectomy (ATL).
  
  
  
  We retrospectively reviewed the records of 1,032 patients undergoing epilepsy surgery at our center from 1977 to 2006. Patients who underwent ATL were included. Seizure outcome was assessed through final follow-up. Those who underwent scalp and IIE (mostly evaluated with temporal subdural strip electrodes) were compared.
  
  
  
  From 497 patients who underwent ATL, 139 did so after IIE placement in the temporal lobes. Mean age at surgery was 32.3±12.3years and median duration of follow-up 24 months (range: 6-36). Fifty-three percent of those evaluated with IIE were seizure-free at their last available visit (vs. 68% evaluated with only scalp EEG, p=0.002). Patients with lesional TLE generally had a better outcome (65.5% seizure free) than those without lesions (56.3%, p=0.093), especially for unilateral TLE diagnosed with IIE. In a multivariate Cox regression analyses adjusted for gender, neuropsychological concordance, pathological findings, and post-operative seizures, bilateral TLE predicted seizure recurrence in IIE patients (HR=2.08, 95% CI: 1.08-4.0, p=0.029).
  
  
  
  More than a half of those who undergo IIE in suspected TLE are seizure free after ATL. IIE allows for the identification of surgical candidates.
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: Andreu
authors.initials: A
authors.lastname: Massot-Tarrús
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: David A
authors.initials: DA
authors.lastname: Steven
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: Richard S
authors.initials: RS
authors.lastname: McLachlan
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: Seyed M
authors.initials: SM
authors.lastname: Mirsattari
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: David
authors.initials: D
authors.lastname: Diosy
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: Andrew G
authors.initials: AG
authors.lastname: Parrent
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: Warren T
authors.initials: WT
authors.lastname: Blume
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada.
authors.forename: John P
authors.initials: JP
authors.lastname: Girvin
authors.affiliation: Epilepsy Program, Department of Clinical Neurological Sciences, Western University, London, Ontario, Canada. Electronic address: jorge.burneo@lhsc.on.ca.
authors.forename: Jorge G
authors.initials: JG
authors.lastname: Burneo
mesh_terms: D000328:Adult; D038481:Anterior Temporal Lobectomy; D000069279:Drug Resistant Epilepsy / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D000069280:Electrocorticography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D005260:Female; D005500:Follow-Up Studies; D007839:Functional Laterality; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D015999:Multivariate Analysis; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D012640:Seizures / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000601:surgery*; D016896:Treatment Outcome
keywords: Bitemporal epilepsy; Intracranial electrodes; Outcome; Seizures; Surgery; Temporal lobe epilepsy