Cerebellar Grey Matter and Lobular Measures and Their Relationship with Core Autistic Symptoms

Structural differences in the cerebellum are among the most consistent neuroanatomical findings in autism spectrum disorder (ASD). We investigated grey matter (GM) and volumetric measurements of the cerebellum in ASD children compared to typically developing (TD) children, and examined the relationship between cerebellar structure and core ASD symptoms. Voxel-based morphometry (VBM) was used to compare whole-brain GM volumes in 33 ASD and 33 TD children (mean age 10.6±4.4 years; range 8-13 years). The cerebellar SUIT atlas was used to compute volumetric measurements of individual cerebellar lobules. Correlations were calculated between scores on autism diagnostic scales and the VBM and volumetric data. Using two analytic approaches, we showed reduced cerebellar Crus I/II GM in ASD, a region which connects to prefrontal and parietal association areas. Importantly, cerebellar GM volume and lobular volumes significantly correlated with ASD symptomology, providing further evidence of a role for the cerebellum in ASD etiology.