title: Good surgical outcome in discordant ictal EEG-MRI unilateral mesial temporal sclerosis patients.
abstract: OBJECTIVE
  Video electroencephalography (vEEG) monitoring of patients with unilateral mesial temporal sclerosis (uMTS) may show concordant or discordant seizure onset in relation to magnetic resonance imaging (MRI) evidence of MTS. Contralateral seizure usually leads to an indication of invasive monitoring. Contralateral seizure onset on invasive monitoring may contraindicate surgery. We evaluated long-term outcome after anteromesial temporal lobectomy (AMTL) in a consecutive series of uMTS patients with concordant and discordant vEEG findings, uniformly submitted to AMTL on the MRI evidence of MTS side without invasive monitoring.
  
  
  METHODS
  We compared surgical outcome of all uMTS patients undergoing vEEG monitoring between January 1999 and April 2005 in our service. Discordant cases were defined by at least one seizure onset contralateral to the MRI evidence of MTS. Good surgical outcome was considered as Engel's class I. We also evaluated ictal SPECT concordance to ictal EEG and surgical outcome.
  
  
  RESULTS
  Fifty-four patients had concordant (C) and 22 had discordant (D) scalp EEG and MRI. Surgical outcome was similar in both groups (C = 74% versus D = 86%). Duration of follow-up was comparable in both groups: C = 56.1 +/- 20.7 months versus D = 59.8 +/- 21.2 months (p = 0.83, nonsignificant). Discordant single-photon emission computed tomography (SPECT) results did not influence surgical outcome.
  
  
  CONCLUSIONS
  Surgical outcome was not influenced by contralateral vEEG seizure onset or contralateral increased flow on ictal SPECT. Although vEEG monitoring should still be performed in these patients, to rule out psychogenic seizures and extratemporal seizure onset, a potentially risky procedure such as invasive monitoring may not only not be indicated in this patient population, but may also lead to patients erroneously being denied surgery.
authors.affiliation: Department of Neurology, Hospital das Clínicas Faculdade de Medicina da Universidade de Sao Paulo, São Paulo, Brazil. castrolh@usp.br
authors.forename: Luiz H
authors.initials: LH
authors.lastname: Castro
authors.forename: Mauricio H
authors.initials: MH
authors.lastname: Serpa
authors.forename: Rosa M
authors.initials: RM
authors.lastname: Valério
authors.forename: Carmen L
authors.initials: CL
authors.lastname: Jorge
authors.forename: Carla R
authors.initials: CR
authors.lastname: Ono
authors.forename: Paula R
authors.initials: PR
authors.lastname: Arantes
authors.forename: Sergio
authors.initials: S
authors.lastname: Rosemberg
authors.forename: Hung Tzu
authors.initials: HT
authors.lastname: Wen
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D038481:Anterior Temporal Lobectomy / Q000379:methods; D002648:Child; D004569:Electroencephalography; D004833:Epilepsy, Temporal Lobe / Q000175:diagnosis / Q000209:etiology / Q000601:surgery; D005260:Female; D005500:Follow-Up Studies; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D012598:Sclerosis / Q000150:complications / Q000175:diagnosis / Q000601:surgery; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000473:pathology* / Q000601:surgery*; D015899:Tomography, Emission-Computed, Single-Photon; D016896:Treatment Outcome; D020535:Video-Assisted Surgery / Q000379:methods*