title: Outcome of surgery in children with focal cortical dysplasia younger than 5 years explored by stereo-electroencephalography.
abstract: OBJECTIVE
  Focal cortical dysplasia (FCD) is the most frequent etiology for drug-resistant epilepsy in young children. Complete removal of the lesion is mandatory to cure the epilepsy. Stereo-EEG (SEEG) is an excellent method to delimitate the zone to be resected in older children and adults. We studied its feasibility in younger children.
  
  
  METHODS
  We retrospectively studied 19 children under 5 years of age who underwent SEEG between January 2009 and December 2012 and were subsequently operated on. FCD was diagnosed in all. We reviewed magnetic resonance imaging (MRI), electrophysiological and clinical data, as well as postoperative seizure outcome. We also included fluoro-deoxyglucose positron emission tomography (FDG-PET) studies, which had been systematically performed before invasive recording in 16 of the 19 children.
  
  
  RESULTS
  The mean patient's age at the time of SEEG was 38.6 months, and the mean age at seizure onset was 8 months. Three patients had normal MRI. No SEEG-associated complications occurred. We were able to delineate the epileptogenic zone in all children, and electrode stimulation localized the motor area when necessary (12 patients). Hypometabolic areas on FDG-PET included the epileptogenic zone in 13 of the 16 children, with a lobar concordance in 9 (56 %) and the same anatomical extent in 6 (38 %). Twelve children subsequently underwent focal or sublobar resection, six had multilobar resection, and one had hemispherotomy. The etiology was FCD type 2 in 15 and FCD type 1 or type 3 in three children. Eighty-four percent of our population have remained seizure-free at a mean follow-up of 29 months (12-48 months).
  
  
  CONCLUSIONS
  Although children with FCD can successfully undergo resective surgery without invasive EEG, poor seizure semiology at this age inclines to perform SEEG when the dysplastic lesion is ill-defined and/or the electroclinical correlation is unclear. In cases with normal imaging as well as with suspected huge malformations, as was the case in 52 % of our patients, we consider it to be indispensable.
authors.affiliation: Department of Pediatric Neurosurgery, Fondation Rothschild, Paris, France, georg.dorfmuller@gmail.com.
authors.forename: G
authors.initials: G
authors.lastname: Dorfmüller
authors.forename: S
authors.initials: S
authors.lastname: Ferrand-Sorbets
authors.forename: M
authors.initials: M
authors.lastname: Fohlen
authors.forename: C
authors.initials: C
authors.lastname: Bulteau
authors.forename: F
authors.initials: F
authors.lastname: Archambaud
authors.forename: O
authors.initials: O
authors.lastname: Delalande
authors.forename: M
authors.initials: M
authors.lastname: Chipaux
authors.forename: D
authors.initials: D
authors.lastname: Taussig
mesh_terms: D001921:Brain / Q000000981:diagnostic imaging / Q000503:physiopathology; D058256:Brain Waves / Q000502:physiology*; D002675:Child, Preschool; D004569:Electroencephalography; D005260:Female; D006801:Humans; D007223:Infant; D008137:Longitudinal Studies; D008297:Male; D054220:Malformations of Cortical Development / Q000473:pathology / Q000503:physiopathology / Q000601:surgery*; D059906:Neuroimaging; D019635:Neurosurgical Procedures / Q000379:methods*; D011859:Radiography; D011877:Radionuclide Imaging; D012189:Retrospective Studies; D016896:Treatment Outcome