Imaging sheds light on mechanisms behind autistic behavior
Chinese researchers announced this week that, using diffusion tensor imaging (DTI), they have been able to identify abnormal connections between brain networks in preschoolers with autism spectrum disorder (ASD), further shedding light on the mechanisms at work behind autistic behavior.
“While developments in brain imaging have enabled the discovery of abnormal brain connectivity in younger children with ASD, the phenomenon has not yet been fully investigated at the brain network level,” study leader and co-author Lin Ma, MD, said in an RSNA release.
Ma and his team at Chinese PLA General Hospital in Beijing said identifying ASD early in life can be crucial to the success of a patient’s treatment—and most cases of autism can be identified within the first few years of a child’s life. Early diagnosis means early treatment, the authors said, and a better chance at being able to function more readily as an adult.
Though scientists don’t necessarily understand the underlying pathophysiology or neurologic basis of autism right now, they do know altered brain connectivity is a key feature.
The researchers compared 21 preschool boys and girls for their trial, all of whom had been diagnosed with autism prior to the study, to 21 of their peers with typical development. All children underwent DTI, and Ma et al. applied graph theory to the imaging results to measure relationships between highly connected areas of the brain.
They found that children with ASD showed significant differences in their basal ganglia and paralimbic-limbic networks, two systems responsible for behavior. The global topologic patterns of white matter networks in this group were also altered, particularly the bilateral caudate, putamen and pallidum nodes in the basal ganglia network and bilateral hippocampus, parahippocampal gyrus, left temporal pole of the superior temporal gyrus and right amygdala nodes in the paralimbic-limbic networks.
“The observed increase in connections between the paralimbic-limbic system and the occipital network demonstrated the important role of the paralimbic-limbic system in childhood ASD,” Ma said. “Disconnections between these networks may be associated with an aberrant observation and imitation capacity in childhood ASD.”
Ma and colleagues noted the areas with significantly altered white matter connectivities were in the brain’s left hemisphere, which could support the “left hemisphere” hypothesis for autism.
“There were correlations between the white matter network’s topologic alterations and the clinical scales of the Childhood Autism Rating Scale, suggesting delayed or stunted maturation processes in the children with ASD,” Ma said. “The imaging finding of those ‘targets’ may be a clue for future diagnosis and even for therapeutic intervention in preschool children with ASD.”
The researchers’ work was published in Radiology this week.
After graduating from Indiana University-Bloomington with a bachelor’s in journalism, Anicka joined TriMed’s Chicago team in 2017 covering cardiology. Close to her heart is long-form journalism, Pilot G-2 pens, dark chocolate and her dog Harper Lee.