Brain volume in autism

Increased brain size has been observed in individuals with autism with a wi de range of cognitive functioning. The purpose of this investigation was to obtain measurements of the brain volume in a sample of nonmentally retarde d autistic individuals. Magnetic resonance imaging scans from 16 nonmentall y retarded individuals with autism and 19 male volunteer comparison subject s were obtained and the following structures were measured: third, fourth, and lateral ventricles and intracranial and cerebral volumes. Mean cerebral and third ventricle volumes in the autistic subjects were significantly gr eater than in the controls when adjusted for intracranial volume. No other significant results were found. Our finding of increased brain volume in au tism is consistent with previous reports in the literature. Additional long itudinal neuroimaging and, more importantly, neuropathologic studies are wa rranted to provide a better understanding of the complexities underlying in creased brain size in autism.