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Study identifies lifespan differences in brain connectivity in autism

Individuals with autism spectrum disorder exhibited abnormal brain morphometry in cognitive and affective parts of the striatum, frontal cortex and temporal cortex, with greatest differences in adolescence.

“Several recent studies have used the anatomical differences in [autism spectrum disorder (ASD)] as the basis for multivariate analyses with the ultimate goal of using these differences as a tool for categorizing ASD. These efforts, however, are yet to be validated in clinical settings. The heterogeneity of anatomical differences in the various samples may also underlie the lack of consistent results in this line of research,” Daan van Rooij, PhD, of Radboud University Medical Center, Nijmegen, the Netherlands, and colleagues wrote.

To assess brain morphometry differences between individuals with ASD and healthy individuals across the lifespan, researchers evaluated a large multinational sample from the Enhancing Neuroimaging Genetics Through Meta-Analysis ASD working group. Study participants with ASD (n = 1,571) and healthy controls (n = 1,651) underwent MRI scans. Researchers used mega-analyses to identify case-control differences in subcortical volumes, cortical thickness and surface area.

ASD was associate with smaller subcortical volumes of the pallidum, putamen, amygdala and nucleus accumbens and increased cortical thickness in the temporal cortex, according to case-control mega-analyses.

Analyses of age effects indicated altered development of cortical thickness in ASD, with greatest differences in adolescence.

Researchers did not observe age-by-ASD interactions in subcortical partitions.

“This study showed the abnormal development of cortical thickness and subcortical volumes in ASD in the largest sample to date, as obtained by the ENIGMA ASD working group... Our age analyses show that subcortical differences in ASD remain relatively stable over the lifespan, while cortical alterations in ASD show a peak in childhood and early adolescence and taper off over adulthood,” the researchers wrote. “Future functional activation and resting-state connectivity studies will want to take into account these differences in maturation and focus on unraveling how the balance between frontal, temporal, and subcortical alterations influences the expression of the ASD phenotype across the lifespan.” – by Amanda Oldt

Disclosures: Rooij reports no relevant financial disclosures. Please see the study for all other authors’ relevant financial disclosures.