New research has revealed subtle brain differences in men with autism spectrum disorder (ASD).
These differences may help explain the persistence of symptoms into adulthood in most people with the disorder, according to researchers at King’s College London.
For the study, researchers used Diffusion Tensor Imaging (DTI), a Magnetic Resonance Imaging (MRI) technique, to identify altered brain connections in people with ASD.
The brain imaging allowed the researchers to compare the networks of white matter in 61 adults with ASD and 61 healthy adults. White matter consists of large bundles of nerve cells that connect different regions of the brain and enable communication between them, the researchers explained.
The scans revealed that men with ASD had differences in brain connections in the frontal lobe, a part of the brain that is crucial to developing language and social interaction skills.
Specifically, these men had altered development of white matter connections in the left side of the brain, the arcuate bundle, which is involved in language, the researchers discovered.
The differences in the arcuate bundle, which connects areas of the brain involved in understanding words and regions related to speech production, were particularly severe in those who had a significant history of delayed echolalia. Very common in ASD, delayed echolalia manifests in the parrot-like repetition of words or sentences.
ASD was also associated with underdevelopment of white matter in the left uncinate bundle, which plays a significant role in face recognition and emotional processing. This also correlated with observations of inappropriate use of facial expressions in childhood, the researchers noted.
“White matter provides key insights which allow us to paint a precise picture of how different parts of the brain develop during critical periods in childhood,” said Dr. Marco Catani from the Institute of Psychiatry, Psychology & Neuroscience at King’s College London.
“We found subtle brain differences in men who at a very young age had severe problems with communication and social interaction. The differences appear to remain even if they have somehow learned to cope with these difficulties in adult life.
“It is worth noting that the brain differences are visible only with the special research techniques we now have at our disposal,” he continued. “These differences are very subtle and potentially reversible. Thanks to neuroimaging studies like this, it may one day be possible to stimulate the development of these faulty brain connections, or to predict how people with autism respond to treatment.”
Catani noted that the study did not include women or children, adding it would be “interesting to explore whether similar differences exist within these groups. For example, research has shown that women appear more resilient than men when it comes to autism, so it will be important if this is explained biologically in their brain development.”
The study was published in the journal Brain.
Source: King’s College London
PHOTO CREDIT: King’s College London.