Rate of White Matter Development During Childhood Also Linked to ASD
Two new studies from UC Davis’ MIND Institute point to possible subtypes of autism associated with brain size and white matter development. The first research involved a longitudinal study that followed the same children from diagnosis to adolescence. The study’s authors used magnetic resonance imaging (MRI) to measure brain size in 294 children with autism and compared their MRI scans to 135 children without the disorder. The brain scans showed evidence of large-sized brains in children with autism compared to the neurotypical children. Previous autism research recognized larger brains in younger children with autism but theorized that there was a period of size normalization later in their development. However, this new study shows this older hypothesis to be incorrect. The MIND Institute researchers were able to prove the error made by the other study by examining the same cohort of children over a long period of time (15 years) versus different children at different points of development like the previous study did. The longitudinal aspect of MIND Institute study enabled the researchers to measure IQ growth within the same individuals making their findings concrete. The second MIND Institute study associated changes in the brain’s white matter growth to levels of severity of autism in some children. White matter allocates the structural connections in the brain which allows different regions of the brain to communicate with each other. This study’s authors found that children who had slower white matter development were more likely to suffer severe symptoms of autism, while children whose white matter developed more quickly had decreased autism severity over time.
