AN MRI STUDY OF BRAIN SIZE IN AUTISM

Objective: This study tons undertaken to obtain detailed measurements of the volume of the brain, using magnetic resonance imaging (MRI), In a carefully selected group of autistic subjects and comparison subjec ts. Method: Twenty-two male autistic subjects and 20 male volunteer co mparison subjects were examined with detailed (1.5-mm slices) MRI thro ughout the entire brain. Total brain, total brain tissue, and total la teral ventricle volumes were measured by using manual tracing and auto mated techniques. Results: After height and performance IQ were contro lled, autistic subjects had significantly greater total brain, total t issue, and total lateral ventricle volumes than comparison subjects. C onclusions: These findings suggest that male autistic subjects have en larged brains and that enlargement is a result of both greater brain t issue volume and greater lateral ventricle volume.