Prevalence of Unrecognized Autism Spectrum Disorders in Epilepsy: A Clinic-Based Study

To assess prevalence of unrecognized autism spectrum disorders (ASDs) in children with epilepsy using Diagnostic and Statistical Manual IV (DSM-IV) criteria and to evaluate factors affecting it in this population. It was a cross-sectional study conducted at a teaching hospital. It included randomly selected 106 children in the age 4-12 years with epilepsy, and without any structural anomaly identifiable on computed tomography/magnetic resonance imaging. Children already diagnosed with ASD were excluded.

Detailed clinical evaluation was carried out. Intelligence quotient (IQ) was assessed using Development Profile-II for all and Binet and Kulshrestha test, wherever possible. Participants were screened using Social Communication Questionnaire (SCQ). Those with SCQ score of ≥15 were evaluated for ASD using DSM-IV criteria. Childhood Autism Rating Scale was administered to assess the severity of autism. Data were analyzed with univariate and logistic regression analyses.

A total of nine children were screened positive, of them, eight were diagnosed with ASD using DSM-IV criteria. The prevalence of unrecognized ASD was 7.5/100. On univariate analysis, intellectual disability (P < 0.01) and young age of onset of epilepsy (P = 0.03) were significantly associated with ASD. On multivariable analysis, only intellectual disability was significantly associated with ASD (P < 0.01). There was no significant association with gender, seizure type, frequency of seizures, intractability of epilepsy, or the number of antiepileptic drugs used.

ASDs are more prevalent in children with epilepsy than in general population. In cases with associated intellectual disability, co-occurrence of ASD is further increased. All children with epilepsy, particularly those with IQ ≤ 50, irrespective of age of onset of epilepsy, seizure type, frequency of seizures, or intractability of epilepsy, should be screened for ASD.