EEG abnormalities and epilepsy in autistic spectrum disorders: clinical and familial correlates

Our aim was to examine the characteristics of EEG findings and epilepsy in autistic spectrum disorders (ASD) and the associated clinical and familial risk factors. Fifty-seven children (86% male) with ASD, mean age 82+/-36.2 months, were included in the study. Thirty-nine (68.4%) children had the diagnosis of autism, 15 (26.3%) had Pervasive Developmental Disorder Not Otherwise Specified, and 3 (5.3%) had high-functioning autism. One hour of sleep and/or awake EEG recordings was obtained for each child. All patients were evaluated with respect to clinical and familial characteristics and with the Childhood Autism Rating Scale, the Autism Behavior Checklist, and the Aberrant Behavior Checklist. The frequency of interictal epileptiform EEG abnormalities (IIEAs) was 24.6% (n=14), and the frequency of epilepsy was 14.2% (n=8). IIEAs were associated with a diagnosis of epilepsy (P=0.0001), Childhood Autism Rating Scale Activity scores (P=0.047), and a history of asthma and allergy (P=0.044). Epilepsy was associated with a family history of epilepsy (P=0.049) and psychiatric problems in the mother during pregnancy (P=0.0026). Future studies with larger samples will help to clarify the possible associations of epilepsy/IIEAs with asthma/allergy, hyperactivity, and familial factors in ASD.