title: Age at onset of epilepsy, pharmacoresistance, and cognitive outcomes: a prospective cohort study.
abstract: OBJECTIVE
  Increasing evidence suggests that uncontrolled seizures have deleterious effects on cognition and behavior, particularly in the developing brain.
  
  
  METHODS
  In a community-based cohort, 198 children, aged <8 years with new-onset epilepsy were followed prospectively and reassessed with the Wechsler Intelligence Scales for Children, Third Edition (WISC-III) 8-9 years later. Linear regression analyses with interactions between age at onset (age) and pharmacoresistance (PR) were used to test whether earlier onset conveyed greater vulnerability to the effects of uncontrolled seizures. Full-scale IQ (FSIQ) and the 4 subdomain scores were examined. Adjustment for adaptive behavior scores in a subset was performed. A dichotomous indicator for IQ <80 or ≥80 was used to permit inclusion of children who were not tested, particularly those who were untestable.
  
  
  RESULTS
  FSIQ was not correlated with age. PR was associated with an 11.4 point lower FSIQ (p = 0.002) and similar decrements in each WISC-III domain. There were substantial age-PR interactions for FSIQ (p = 0.003) and 3 domain scores, indicating a lessening impact of PR with increasing age. The dichotomous IQ indicator was strongly correlated with age at onset in the pharmacoresistant group (p < 0.0001) and not in the non-pharmacoresistant group (p = 0.61). Adjustment for adaptive behavior measured near onset did not alter the conclusions.
  
  
  CONCLUSIONS
  Uncontrolled seizures impair cognitive function with effects being most severe in infancy and lessening with increasing age at onset. These findings further emphasize the need for early aggressive treatment and seizure control in infants and young children.
authors.affiliation: Epilepsy Center, Ann and Robert H. Lurie Children's Hospital of Chicago, IL, USA. atberg@luriechildrens.org
authors.forename: Anne T
authors.initials: AT
authors.lastname: Berg
authors.forename: Frank A
authors.initials: FA
authors.lastname: Zelko
authors.forename: Susan R
authors.initials: SR
authors.lastname: Levy
authors.forename: Francine M
authors.initials: FM
authors.lastname: Testa
mesh_terms: D017668:Age of Onset; D002648:Child; D002675:Child, Preschool; D003072:Cognition Disorders / Q000188:drug therapy / Q000453:epidemiology / Q000209:etiology*; D015331:Cohort Studies; D004351:Drug Resistance; D004827:Epilepsy / Q000150:complications* / Q000188:drug therapy* / Q000453:epidemiology; D005260:Female; D006801:Humans; D007360:Intelligence; D008297:Male; D011446:Prospective Studies; D016896:Treatment Outcome