Objective: The autistic spectrum disorder (ASD) is a lifelong disorder characterized by a defect in communication, social interaction and stereotype patterns of behavior. The etiology of ASD is probably heterogenous. EEG abnormalities were observed in autistic patients, but these findings are mostly based on the visual analysis and scarce studies used quantified EEG parameters. Changes in connectivity of various parts of brain cortex were described in some studies and that is why we decided to investigate an EEG measure which is capable to evaluate the connectivity: The coherence. Study aims are to,Assess the hypothesis of connectivity changes; Assess the impact of epileptiform discharges on neuropsychological development.
Methods: We present a small study of 24 children with ASD who underwent complex neuropsychological, neurological, sleep video-EEG (whole night and part-day) and MRI of brain investigations. The video EEG and MRI data are compared with quasi-normal EEG and MRI data from the control group. The EEG data were evaluated by experienced EEG reader and then the parts of EEG in relaxed wakefulness were quantified in terms of inter-channel coherence in several EEG channels.
Results: A coherence analysis across several EEG channels revealed a statistically significant correlation between inter hemispheric coherence of the rear temporal regions (T5-T6) at 16-31 Hz and Childhood Autism Rating Scale raw scores.
Conclusion: The changes in connectivity measured by the coherence might be a part of pathophysiology of the ASD.