EEG changes and neuroimaging abnormalities in relevance to severity of autism

Abstract

Background: Autism is currently viewed as a genetically determined neurodevelopmental disorder although its defi nite underlying etiology remains to be established.
Aim of the Study: Our purpose was to assess autism related morphological
neuroimaging changes of the brain and EEG abnormalities in correlation to the degree of disease severity.
Patients and Methods: Seventeen cases with classic autism, 13 males and 4 females were included in the study. Severity of the disease was assessed both clinically and by Childhood Autism Rating Scale (CARS). MRI changes and EEG abnormalities were detected in seven patients, mostly severely and moderately affected.
Results: Hypoplasia of cerebellar vermian lobules is the most replicated MRI abnormality in our patients (18%). Periventricular white matter dysmyelination is detected in 12% of studied cases. 29% of the cases have EEG abnormalities. Head circumference above 97th centiles is detected in 18% of cases. The increased head circumference, when in combination with EEG abnormalities, positively correlates with the degree of disease severity. Conclusion: Although, no defi nite correlation could be established between the studied parameters and disease severity, most patients in the present study who exhibited MRI abnormality, EEG changes and/or increased head circumference (H.C) manifested severe form of autism. The absence of correlation may be attributed to lack of statistical power, resulting from small sample size. However, the correlation was not solidly excluded therefore, the recommendation of further neuroradiological evaluation as well as the implementation of
newer techniques, might help future elucidating the etiology of autism.

Keywords: Autism, MRI, EEG, brain development.