Background. Approximately one third of the parents of children with pervasive developmental disorders or autistic spectrum disorders reports an early regression of unknown cause in their children's language, sociability, and play. Seizures or an epileptiform electroencephalogram (EEG) are associated with language regression in acquired epileptic aphasia (Landau–Kleffner syndrome) and some other pediatric epileptic syndromes. The importance of epilepsy or epileptic EEGs as contributors to autistic regression is not known.

Method. Subjects were 482 boys and 103 girls on the autistic spectrum seen consecutively in consultation by one child neurologist. Data on autistic regression, seizures, sleep EEGs, and cognitive function were entered prospectively into a data base.

Results. Of the 585 children, 176 (30%) had a history of regression, and 66 children (11%) had a history of epilepsy, defined as two or more unprovoked seizures. Among 392 children with available sleep EEGs, the EEG was epileptiform in 59% of the 66 epileptic children and 8% of the 335 nonepileptic children. Regression had occurred equally among children without seizures and in those with epilepsy. Regression was associated with an epileptiform EEG in 14% of 155 nonepileptic children who had undergone a regression, as opposed to 6% of 364 children with neither regression nor epilepsy. Mean age at regression was 21 months. There was no difference in the proportion of children with epilepsy or epileptiform EEGs who had regressed before or after 2 years of age. Approximately half of the epileptiform discharges were centrotemporal, whether or not the child was epileptic or had regressed. Children with lower cognitive function were more likely to have undergone regression than those with better cognitive skills (34% vs 20%).

Conclusion. Epilepsy or epileptiform EEGs occur in a significant minority of autistic children with a history of regression and in a smaller minority without regression. Prompt recognition of regression and recording of prolonged sleep EEGs is recommended, even though information on the potential efficacy of antiepileptic treatment to improve language and behavior in autistic children with epilepsy or an epileptiform EEG is still lacking.

You do not currently have access to this content.