The importance of Epilepsy in Autism Spectrum Disorder
ABSTRACT Background: Studies report high prevalence of epilepsy in autism spectrum disorder (ASD) and vice versa. However, few studies have examined if the association alters the phenotypical expression. Objectives: (1) To describe the impact of epilepsy on ASD symptomatology and (2) to investigate whether symptomatic expression of ASD in individuals with epilepsy differs from individuals with ASD but without epilepsy. Methods: The data came from The Child and Adolescent Twin Study (CATSS) a longitudinal Swedish study in which parents of twins are interviewed about the somatic and mental health of their children. The present study included 26,863 twins that were classified into different groups depending on the presence and level of ASD symptomatology, and the presence of epilepsy. Two-way ANOVAs with Bonferroni correction was used to compare mean values and variation within the groups and then a ranking of the symptoms was conducted. Results: More subjects (7.4%) with epilepsy screened positive for ASD (p-value<0.001) compared to 0.9% in the general population, and 6.1% of all subjects with ASD had epilepsy (p-value<0.001) compared to 0.8% of the general population. The presence of epilepsy was associated with significantly elevated difficulties within the language domain in individuals with ASD (p-value = 0.004). Stereotyped and repetitive behavior and social interaction difficulties in individuals with ASD were largely unaffected by the presence of epilepsy. Individuals who had Epilepsy with or without ASD more frequently had problems with language and social interaction symptoms while individuals with ASD without epilepsy more frequently endorsed symptoms of stereotyped and repetitive behavior. Discussion and conclusion: This study confirms that Epilepsy and ASD often coexist. The association tends to increase language difficulties. Moreover, symptoms of ASD seem to display a somewhat different profile conditioned on the presence of epilepsy. This may have meaningful implications in diagnostic, treatment and follow up settings for children with ASD with or without epilepsy. Keywords: Autism, Autism spectrum disorder, Epilepsy.