Scientists have detected differences in the brains of six month old babies who later go on to be diagnosed with autism.
They say changes in brain development that underlie autism spectrum disorder (ASD) may be seen in children as young as six months, according to research reported online in the American Journal of Psychiatry.
While core behaviours associated with autism spectrum disorder (ASD), such as impaired social communication and repetitive behaviours, tend to be identified after a baby’s first birthday, researchers found clear differences in brain communication pathways as early in six month olds.
As part of the Infant Brain Imaging Study (IBIS), senior author Joe Piven, from the University of North Carolina, and his colleagues studied early brain and behaviour development in 92 infants.
These infants had older siblings on the autism spectrum and, so, were at elevated risk of developing ASD themselves.
“These results offer promise that we may one day be able to identify infants at risk for autism before the behavioural symptoms are present,” said study co-author Geri Dawson, Autism Speaks chief science officer. “The goal,” she adds, “is to intervene as early as possible to prevent or reduce the onset of disabling symptoms.”
In their report, the researchers describe using a magnetic resonance imaging technology called diffusion tensor imaging to evaluate the brains of infants at six months, one year and two years of age. This allowed them to create three-dimensional pictures showing changes over time in each infant’s “white matter.” White matter represents the part of the brain that is particularly rich in the nerve fibres that form major information pathways between different brain regions.
The 28 infants who went on to develop ASD showed different white matter development for 12 of the 15 major brain pathways studied compared with 64 infants who did not go on to develop ASD. At six months, there was evidence that the white matter fibre tracts were different in infants who later developed ASD from those of infant siblings who did not develop ASD, and over time it appears that there is a slowing in white matter development.
It is a brain marker that differs in children who go on to be classified with autism. These developmental differences may suggest slower white matter development during early childhood, when the brain is making and strengthening vital connections.