Brain Enlargement in Autism due to Brain Changes Occurring Before Age 2

Source: 
Science Daily
Date Published: 
May 3, 2011
Abstract: 

In 2005, researchers from the University of North Carolina at Chapel Hill found that 2-year-old children with autism have brains up to 10 percent larger than children of the same age without autism. A follow-up study by UNC researchers has found that the children who had enlarged brains at age 2 continued to have enlarged brains at ages 4 and 5, but the amount of the enlargement was to the same degree found at age 2. This increased brain growth did not continue beyond 2 years of age and the changes detected at age 2 were due to overgrowth prior to that time point. In addition, the study found that the cortical enlargement was associated with increased folding on the surface of the brain (or increased surface area) and not an increase in the thickness of outer layer of the brain (or gray matter).