A diffusion tensor imaging study of the cerebellar pathways in children with autism spectrum disorder.

Children with autistic spectrum disorder are known to have histopathological abnormalities in the cerebellum. Diffusion tensor imaging has been utilized to study abnormalities in connectivity and microintegrity in brains of such children. A region of interest approach was adopted to study cerebellar outflow and inflow pathways in 27 children (24 males; mean age, 5.0 years) with autism, and comparison was made with 16 normally developing controls. An increase in the mean diffusivity of bilateral superior cerebellar peduncles in those with autistic spectrum disorder was noted, as was a reversal of the asymmetry pattern in fractional anisotropy of the middle cerebellar peduncle and the inferior cerebellar peduncle in the autistic spectrum disorder group, compared with controls. This study reiterates the underconnectivity between the cerebellum and neocortex, using diffusion tensor imaging.