(ORDO NEWS) — A brain structure called the amygdala grows too fast in children who are diagnosed with autism by the age of two, a new study says.
The researchers found that this overgrowth occurs between 6 and 12 months of age, before children are usually diagnosed with autism.
“Our study suggests that the optimal time to start intervention and support for children who are most likely to develop autism may be in the first year of life,” said study senior author Dr. Joseph Piven, professor of psychiatry and pediatrics at the University of North Carolina at Chapelle. Hill.
The amygdala is an amygdala-shaped structure deep in the brain that is involved in processing emotions, including feelings of fear, as well as interpreting facial expressions.
Researchers already knew that the amygdala in school-age children with autism is larger than in children without autism, but exactly when this enlargement begins was unknown.
In the new study, scientists scanned the brains of more than 400 infants, including 270 children at increased risk of developing autism because they had an older sibling with the condition; 109 children with typical development; and 29 children with Fragile X syndrome, a genetic disorder that causes developmental delay and mental retardation.
The children underwent MRI at six months, 12 months and 24 months. By 24 months, 58 (or about 21 percent) of the at-risk children were diagnosed with autism.
The researchers found that at six months of age, all babies had the same size tonsils. But by 12 months, children who subsequently developed autism had enlarged tonsils compared to children who did not develop autism and children with Fragile X syndrome. What’s more, children at risk had enlarged tonsils.
What’s more, the children with the fastest growing tonsils had the most severe autism symptoms.
The faster the amygdala grew in infancy, the more social difficulties the child showed when he was diagnosed with autism a year later, said first study author Mark Shen, assistant professor of psychiatry and neurology at UNC Chapel Hill.
The researchers hypothesized that early visual and sensory processing problems in infancy may put stress on the amygdala, leading to overgrowth. (The amygdala receives signals from the brain’s visual system and other sensory systems to detect threats.)
Studies have shown that children who are later diagnosed with autism had trouble paying attention to visual stimuli in infancy.
Intervention in children at high risk of developing autism could be aimed at improving the processing of visual and other sensory information in infants, Piven says.
According to the National Institutes of Health, early intervention for autism usually begins between the ages of two and three, when a child is diagnosed with autism.
However, some studies have tested the intervention on children who were at risk for autism because they had a sibling with autism, or on children with early symptoms such as visual fixation on certain objects, according to autism news site Spectrum.
For example, a small 2014 study tested an intervention in children aged 6 to 15 months that taught parents new ways to interact with their children, such as ways to shift a child’s attention away from an obsessed object, and found that the therapy reduced symptoms. autism by age 3, Spektr reports.
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