Epilepsy in adolescents and young adults with autistic disorder.

Since the first description by Kanner (1943) the association between autistic disorder (AD) and epilepsy has been observed in 4-42% of patients. Some authors reported that seizures prevailed in adolescence but a systematic investigation has never been undertaken. We examined retrospectively 60 patients divided into two groups (with and without epilepsy and EEG paroxysmal abnormalities) with AD unrelated to a congenital or acquired encephalopathy (mean age 17 years 2 months). The aim was to investigate epilepsy, EEG paroxysmal abnormalities and possible etiological factors. The prevalence of epilepsy was 38.3%, much higher than that in a normal population of a similar age (6.6 per thousand). The prevalence of EEG paroxysmal abnormalities without epilepsy was 6.7%, higher than that in a population of adolescents and adults with psychiatric pathologies (2. 6%). Seizure onset was after age 12 years in 66.7% of cases. The most common type of epilepsy was partial in 65.2% and four patients (17.4%) had a benign childhood epilepsy with centro-temporal spikes. At the last observation 44.4% of patients had been seizure-free for 2 years or more. There were no organic factors influencing the development of epilepsy but familial and personal antecedents, mental retardation and CT scan/MRI data may suggest an early brain dysfunction responsible for AD and epilepsy.