Autism Spectrum Disorder With and Without Epilepsy: A Comparative Study

Background: Autism spectrum disorder (ASD) and epilepsy have shared neurobiology. Limited literature exists on the differentiating features of ASD and ASD with epilepsy (ASD-E) phenotypes. This study was conducted to compare the clinical, electrophysiological and radiological profiles among them. Methods: This is a retrospective descriptive study of ASD patients who attended our hospital between 2011 and 2021. The demographic, clinical, developmental, electroencephalography (EEG) and neuroimaging parameters were compared between ASD-E and ASD groups using Pearson’s chi square test and t test. Logistic regression analysis with variables of p value < 0.05 was performed to identify factors associated with epilepsy in ASD. Results: There were 441 ASD patients, with mean age 7.3 ± 4.6 years, 319 (72%) were males. ASD- E phenotype was present in 191 (43.3%) patients. Global developmental delay (GDD) (78% vs 22%, p< 0.001 ), psychomotor regression (34.3% vs 10.3%, p<0.001), background activity (BGA) slowing (62% vs 17%, p<0.001), interictal epileptiform discharges (IEDs) (81% vs 35%, p< 0.001) and structural abnormality in neuroimaging ( 48% vs 32%, p 0.013) were higher in ASD-E than in ASD group. In multivariate analysis, female sex [odd’s ratio (OR) 2.744, 95%CI 1.145-6.576, p 0.024], GDD (OR 2.852, 95% CI 1.185-6.862, p 0.019), BGA slowing (OR 4.141, 95% CI 1.621-10.581, p 0.003) and IEDs (OR 4.282, 95% CI 1.641-11.171, p 0.003) showed higher odds for ASD-E phenotype. Conclusion: There was significant differences between demographic, developmental and EEG profile among ASD and ASD-E. Female sex, GDD and IEDs were strongly associated with ASD-E phenotype.