Neuropsychological correlates of electroencephalograms in children with epilepsy.

Introduction: This study examined the degree to which neurophysiological activity on routine clinical EEG is associated with neuropsychological deficiencies in children with epilepsy.

Methods: Ninety-five children with epilepsy (58 chronic, 37 recent-onset; mean age = 10.41 years, S.D. = 2.87 years; mean age at onset = 5.86 years, S.D. = 3.46 years) completed a neuropsychological battery. Neurophysiological data were collected from the most recent EEG.

Results: In the recent-onset sample, no neuropsychological scores were related to any EEG variable. In the chronic sample, however, presence of slow-wave activity was related to memory impairment (p < 0.01). Post-hoc analyses on other neuropsychological measures showed localization of epileptiform activity (EA) might be related to verbal learning.

Discussion: Children with slow-wave activity on EEG might be at increased risk for developing neuropsychological deficits. When these abnormalities are observed on a child's EEG, closer monitoring of cognitive and academic functioning seems warranted. Differences between these findings and past research suggest that conclusions drawn from adult surgical studies cannot be generalized to pediatric patients, especially recent-onset samples, without qualification. Differences between the recent-onset and chronic samples in this cross-sectional study raise the possibility that neurophysiological abnormalities have a cumulative effect on cognitive development.