An MRI study of increased cortical thickness in autism.

Objective: The purpose of this study was to examine cortical thickness in autism in light of the postmortem evidence of cortical abnormalities of the disorder. Method: Magnetic resonance imaging (MRI) scans were acquired from 17 children with autism and 14 healthy comparison subjects, and sulcal and gyral thickness were measured for the total brain and for all lobes. Results: Increases in total cerebral sulcal and gyral thickness were observed in children with autism relative to comparison subjects. Similar findings were noted in the temporal and parietal lobes but not in the frontal and occipital lobes. Conclusions: These preliminary findings indicate that increased cortical thickness may contribute to the increased gray matter volume and total brain size that have been observed in autism and may also be related to anomalies in cortical connectivity.