An MRI study of the basal ganglia in autism

1. High-resolution MRI scans were obtained from 35 relatively high-function ing persons with autism and 36 healthy controls, comparable in age, gender, and IQ. 2. Volumetric measurements were obtained from manual tracing of the bilater al caudate, putamen, and globus pallidus. 3. An increased volume of the caudate nuclei was found in subjects with aut ism. Caudate enlargement was proportional to increased total brain volume i n subjects with autism. 4. Caudate volume was associated with compulsions and rituals, difficulties with minor change, and complex motor mannerisms in autism. 5. Based on evidence of caudate abnormalities, a second MRI study was compl eted which replicated the finding of caudate enlargement in autism using an independent sample. 6. The caudate may be part of an abnormal distributed neural network in aut ism and involved in the ritualistic - repetitive behaviors of the disorder.