Electroencephalographic abnormalities and clinical phenotypes in children with autism spectrum disorder: a single center cohort study.

Background: Electroencephalographic (EEG) abnormalities are frequently observed in children with autism spectrum disorder (ASD), even in the absence of clinical seizures. However, the clinical significance of different EEG patterns in ASD remains incompletely understood. Objective: To investigate associations between EEG abnormalities and selected clinical characteristics in children with ASD. Methods: This study analyzed medical records of 180 children with ASD hospitalized at the Pediatric Neurology Department at the Upper Silesian Child Health Center in Katowice. Patients were stratified by epilepsy diagnosis and EEG characteristics (normal, non-paroxysmal changes, paroxysmal changes). Clinical variables analyzed included developmental milestones, intellectual disability severity, sleep disturbances, hyperactivity, sensory integration disorders, aggressive behaviors, and motor deficits. Statistical analysis employed Mann-Whitney Results: Sleep disorders showed significant association with EEG pattern type ( Conclusion: Non-paroxysmal EEG abnormalities may represent a distinct neurophysiological correlate of sleep disorders in children with ASD. Comorbid epilepsy is strongly associated with intellectual disability severity, supporting the need for comprehensive neurological evaluation in this population. While broad categorical EEG patterns did not reveal significant associations with most clinical manifestations in our sample, more granular EEG analysis may detect subtle correlations not apparent with our simplified classification approach.