[Mental deterioration in childhood epilepsy. I. Neuropsychological and electroencephalographic studies].

To clarify the pathogenesis of mental deterioration in epilepsy, neuropsychological and electroencephalographic studies were performed. Thirty-seven children were classified into two groups: group I consisted of 24 children with mental deterioration during the clinical course of their epilepsy, and group II consisted of 13 children without mental deterioration. Mental deterioration was assessed on the basis of the intelligence test scores during follow-up studies. The mean intelligence quotient of 24 children in group I decreased from 91.8 +/- 11.5 to 64.3 +/- 15.4 during a mean period of 4.4 years. Significant differences were found between the two groups in the levels of both representation (association function) and automation (auditory closure, visual recognition and visual-motor function). There were also significant differences between the two groups in the continuation of epileptic discharges on EEG, in the persistence of epileptic attacks at the final visit, and in the numbers of antiepileptic drugs at the neuropsychological examination. The degree of mental deterioration was correlated with the defect in the association function and, eleven children in group I showed mental deterioration even after their attacks had been suppressed.