title: Early seizure onset and dysplastic lesion extent independently disrupt cognitive networks.
abstract: OBJECTIVE
  To determine the most important factors influencing neuropsychological performance in children with intractable epilepsy due to focal cortical dysplasia and the nature of the interaction among significant variables.
  
  
  METHODS
  Surgical patients with histologically verified focal cortical dysplasia were retrospectively evaluated to determine the impact of histopathology, extent of lobar involvement, hemispheric laterality, age at onset, and duration of epilepsy on cognitive functioning. A composite neuropsychological variable was obtained by transforming data from 5 major cognitive domains using principal components analysis. Multiple regression was used to examine the unique contributions of predictor variables on composite cognition and Full Scale IQ. Data were qualitatively evaluated for nonstatistical trends.
  
  
  RESULTS
  Poor cognitive outcomes were associated with early age at onset of epilepsy (AOE) and widespread dysplastic involvement. Extent of dysplasia and AOE together accounted for 35% of Full Scale IQ variance, and 21% of composite cognitive performance. Each factor contributed independently to cognitive dysfunction.
  
  
  CONCLUSIONS
  Early AOE disrupts critical periods of development and leads to poor cognitive outcome, but children with multilobar dysplasia are likely to have diminished cognitive skills regardless of AOE. Later AOE is not expected to mitigate deficits because of widespread pathology, nor would a localized lesion be likely to mollify the developmental deficits resulting from early AOE.
authors.affiliation: Brain Institute, Miami Children's Hospital, FL, USA. bkorman@mch.com
authors.forename: Brandon
authors.initials: B
authors.lastname: Korman
authors.forename: Pavel
authors.initials: P
authors.lastname: Krsek
authors.forename: Michael
authors.initials: M
authors.lastname: Duchowny
authors.forename: Bruno
authors.initials: B
authors.lastname: Maton
authors.forename: Esperanza
authors.initials: E
authors.lastname: Pacheco-Jacome
authors.forename: Gustavo
authors.initials: G
authors.lastname: Rey
mesh_terms: D000293:Adolescent; D002540:Cerebral Cortex / Q000503:physiopathology*; D002648:Child; D002675:Child, Preschool; D003071:Cognition; D003072:Cognition Disorders / Q000209:etiology / Q000503:physiopathology*; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D054220:Malformations of Cortical Development / Q000150:complications / Q000503:physiopathology*; D009415:Nerve Net / Q000503:physiopathology*; D012640:Seizures / Q000150:complications / Q000503:physiopathology*; D055815:Young Adult