Healthy Kids : Baby Brains May Predict Autism

Michele Munz

Researchers have discovered that significant differences in brain development occur as early as 6 months old in children who develop autism.

"We didn't expect that almost every pathway we examined was going to show these differences," said Dr. Kelly Botteron, a Washington University child psychiatrist at St. Louis Children's Hospital. "That was very striking."

Washington University School of Medicine has joined with three other research centers to form the Infant Brain Imaging Study Network. Together, the scientists studied 92 infants who have older siblings with autism and are at higher risk for developing the disorder, marked by impairments in communication and social skills. The findings were published online last month in the American Journal of Psychiatry.

The study looked at the brain's white matter -- made up of nerve fibers that send information to different parts of the brain -- by conducting brain scans on the children after they fell asleep at night. The scans were done at the age of 6 months, 12 months and 24 months. Twenty-eight of the of the study participants were diagnosed with autism spectrum disorders by age 2.

While researchers expected some parts of the brain to show differences, they were surprised to find so many so early in infancy. Researchers analyzed 15 separate tracts of white matter and found the infants with autism showed differences in all but three of the tracts.

"As this study moves forward, we may want to scan babies at even younger ages so that we can try to see how early this pattern is emerging," Botteron said.

The brain changes were identified using fractional anisotropy, which measures the movement of water molecules through brain tissue. The molecules flow at particular speeds and directions depending on the tissue structure.

The researchers discovered that in infants with autism, the water movement is quicker and more organized -- meaning the development of their neural pathways is more advanced. "They are looking like they are developing mentally ahead of others," Botteron said.

But around 12 months, the movement is similar to that of other infants. And by 24 months, it becomes slower and more random.

The hope is that this information can lead to a way to diagnose children at younger ages because early intervention has been shown to improve symptoms. Children are often diagnosed around the age of 2 using behavioral and developmental tests, but many with milder forms are not diagnosed until later.

"At this point, it's preliminary, albeit a great, first step toward thinking about developing a biomarker for risk in advance of our current ability to diagnose autism," said the study's lead author Jason Wolff, a postdoctoral fellow at the Carolina Institute for Developmental Disabilities at the University of North Carolina at Chapel Hill.

Researchers are seeking more families with high-risk infants to participate in the study.

For information, contact Lisa Flake at 1-888-845-6786, or flakel@psychiatry.wustl.edu.

(c)2012 the St. Louis Post-Dispatch

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