Children with autism spectrum disorders (ASD) experience an extra burst in brain size before reaching 2 years old, new research shows.
Scientists already know that children with autism have larger brains compared to other children without the disorders. Now that researchers understand when brain enlargement occurs, they can focus on why it happens and even try to develop treatments for the disorders before they take hold. Although doctors diagnose autism at 2 years of age at the earliest, there are behavioral signs of ASD beginning at six months.
In a study published in the Archives of General Psychiatry, researchers focused on 59 children with ASD and 38 control children with typical developmental patterns and others with developmental delay, or kids who reach milestones such as learning to talk later than others.
Kids with developmental delay were included because they had IQs similar to the ASD group, which allowed for more detailed comparisons, the researchers write.
The brains of children with ASD were scanned with a functional MRI machine when they were 2 years old. Researchers found these children’s brains, specifically their cerebral areas, were larger than those of other kids. But roughly two to three years later, when the same group was between 4 and 5 years old, the children’s brains were scanned again to assess whether they continued to grow at faster rates.
This wasn’t the case. At this age, kids’ brains with ASD were still larger than other children without the disorder, but appeared to grow at normal rates from the previous time they were imaged with fMRI.
Authors of the paper admit their sample size is small and more research needs to be done. In general, though, the research furthers our understanding of ASDs and may open the door to ways to address or treat them.
Doctors describe ASDs as developmental disabilities that give rise to communication problems and issues socializing with others. Because symptoms of ASDs vary, they’re now diagnosed on a spectrum rather under a single disorder. Out of every 1,000 children in the United States, experts estimate that six will develop an ASD, according to the National Institute of Neurological Disorders and Stroke.
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