r Human Brain Mapping 33:1470–1489 (2012) r Brain Structure Anomalies in Autism Spectrum Disorder—A Meta-Analysis of VBM Studies Using Anatomic Likelihood Estimation

r r Abstract: Autism spectrum disorders (ASD) are pervasive developmental disorders with characteristic core symptoms such as impairments in social interaction, deviance in communication, repetitive and ster-eotyped behavior, and impaired motor skills. Anomalies of brain structure have repeatedly been hypothe-sized to play a major role in the etiopathogenesis of the disorder. Our objective was to perform unbiased meta-analysis on brain structure changes as reported in the current ASD literature. We thus conducted a comprehensive search for morphometric studies by Pubmed query and literature review. We used a revised version of the activation likelihood estimation (ALE) approach for coordinate-based meta-analysis of neuroimaging results. Probabilistic cytoarchitectonic maps were applied to compare the localization of the obtained significant effects to histological areas. Each of the significant ALE clusters was analyzed separately for age effects on gray and white matter density changes. We found six significant clusters of convergence indicating disturbances in the brain structure of ASD patients, including the lateral occipital lobe, the pericentral region, the medial temporal lobe, the basal ganglia, and proximate to the right parietal operculum. Our study provides the first quantitative summary of brain structure changes reported in liter-ature on autism spectrum disorders. In contrast to the rather small sample sizes of the original studies