Brain differences evident at 6 months in infants who develop autism
A new UNC-led study has discovered major changes take place in the brains of infants who are later diagnosed with autism.
As early as 6 months of age, imaging scans showed significant differences in brain development between children who later developed autism and those who did not. Follow up scans on the toddlers through to 24 months old continued to find ongoing differences.
“It’s a promising finding,” said Jason J. Wolff, Ph.D., study lead author and a postdoctoral fellow at UNC’s Carolina Institute for Developmental Disabilities. “At this point, it’s a preliminary albeit great first step towards thinking about developing a biomarker for risk in advance of our current ability to diagnose autism.”
The study also suggests, Wolff said, that autism does not appear suddenly in young children, but instead develops over time during infancy. This raises the possibility “that we may be able to interrupt that process with targeted intervention.”
Dr. Joseph Piven, director of the institute, is senior author of the study.
The findings were published online Friday, Feb. 17 by the American Journal of Psychiatry. They are the latest results from the ongoing Infant Brain Imaging Study (IBIS) Network, which is funded by the National Institutes of Health and headquartered at UNC.
Researchers followed 92 children considered at high risk of developing autism because they have older siblings with the condition. Using brain imaging scans, scientists measured development of the infants’ white matter fiber tracts – pathways that connect brain regions. They found significant differences in 12 of the 15 pathways examined. Furthermore, infants who later developed autism spectrum disorders (30 percent of the group) had elevated white matter measurements at 6 months of age, but then experienced slower change over time; by 24 months, they had lower measures than infants without autism.
“This evidence, which implicates multiple fiber pathways, suggests that autism is a whole-brain phenomenon not isolated to any particular brain region,” Wolff said.
(Above: A visualization of white matter pathways in the brains of infants at-risk for autism. Warmer colors represent levels of white matter organization and development. Image created by Jason Wolff.)