Washington, Feb 18 : Significant differences in brain development can be seen in infants who later develop autism, in as little a time as six months' from birth, as compared to other infants who don't, a research has found.
The study, by scientists at Washington University School of Medicine in St Louis, the University of North Carolina at Chapel Hill and other centres, involved infants considered to be at high risk for autism because they had an older sibling with the diagnosis.
The new research, which relied on brain scans acquired at night while infants were naturally sleeping, suggests that autism doesn't appear abruptly, but instead develops over time during infancy.
"We were surprised that there were so many differences so early in infancy," said co-author Kelly N Botteron, MD, who is leading the effort at the Washington University study site.
"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," she said.
The new findings involved brain scans from 92 infants who had completed diffusion tensor imaging (DTI), a type of MRI scan, at 6 months and behavioural assessments at 24 months of age. Most also had additional scans at 12 months or 24 months or both.
By 24 months, 28 of the infants (30 percent) met the diagnostic criteria for autism spectrum disorders. Scans of the infants with autism revealed changes in the pathways that connect brain regions to one another. In particular, the researchers found changes in multiple fibre pathways in the brain's white matter.
"The idea that connections may be less organized in children with autism fits with our hypothesis.
"These children may have some changes in the brain's gray matter, too, but the way their neurons speak to each other clearly seems to be disrupted," said Botteron, a Washington University child psychiatrist at St. Louis Children's Hospital.
The findings of the study are published online in the American Journal of Psychiatry. (ANI)