Abstracts

Rationale: We aim to systematically review the literature to determine the incidence and prevalence of autism in epilepsy and epilepsy in autism, two conditions that are often comorbid. Methods: We adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses standards. MEDLINE, EMBASE, PsycINFO, and the Cochrane Database of Systematic Reviews were searched from inception until July 4, 2016.  Studies were included if they reported an incidence or prevalence of autism in epilepsy or epilepsy in autism. These estimates were described using mean, standard deviation (SD), median, and interquartile range (IQR). Results: Seventy-one studies reporting on 283,151 patients were included. The median overall period prevalence of epilepsy in people with autism was 11.9% compared to a period prevalence of 0.6% in the general population. The median overall period prevalence of autism in people with epilepsy was 9.0% compared to a period prevalence of 0.8% in the general population. We observed trends for sex as the prevalence of autism in epilepsy was higher in males while the prevalence of epilepsy in autism was higher in females. It is important to interpret these estimates with caution as there was significant heterogeneity between studies. Conclusions: Despite the heterogeneity between studies,the prevalence of epilepsy in people with autism, and vice-versa, was consistently higher than the prevalence of each of these conditions in the general population. These findings highlight the importance of screening for autism in people who have epilepsy and epilepsy in people who have autism. Funding: This study was in part funded by the Hotchkiss Brain Institute at the University of Calgary.  N. Jette is the holder of a Canada Research Chair in Neurological Health Services Research.