Performance of children with epilepsy and normal age-matched controls on the WISC-III

Research findings regarding the effects of childhood epilepsy on general intelligence have produced variable results. The aim of this study was to investigate the effects of epilepsy, age of seizure onset, and Antiepileptic Drugs (AED) on intellectual ability as assessed by the Wechsler Intelligence Scale for Children, 3rd Edition (WISC-III; Wechsler, 1991). This study included children with epilepsy assessed with the WISC-III who achieved either a Full Scale, Verbal Scale, or Performance Scale IQ score >or= 70. A clinical sample of children diagnosed with epilepsy (n = 32) were age- and gender-matched with subjects from the normative standardization sample for the WISC-III, yielding a total sample of 64 subjects. Comparison using a MANOVA revealed significant differences across WISC-III Index standard scores (p = 0.0005) and subtest scaled scores (p = 0.0013), with control participants performing better than epileptic participants. Secondary analyses were also conducted considering monotherapy (n = 14) versus polytherapy (n = 11), and age of seizure onset (<6 years, n = 12; 6 > years, n = 15). MANOVA comparisons revealed no significant differences between groups across WISC-III Index standard scores.