Examining the Boundary Sharpness Coefficient as an Index of Cortical Microstructure in Autism Spectrum Disorder.

TitleExamining the Boundary Sharpness Coefficient as an Index of Cortical Microstructure in Autism Spectrum Disorder.
Publication TypeJournal Article
Year of Publication2021
AuthorsOlafson E, Bedford SA, Devenyi GA, Patel R, Tullo S, Park MTae M, Parent O, Anagnostou E, Baron-Cohen S, Bullmore ET, Chura LR, Craig MC, Ecker C, Floris DL, Holt RJ, Lenroot R, Lerch JP, Lombardo MV, Murphy DGM, Raznahan A, Ruigrok ANV, Spencer MD, Suckling J, Taylor MJ, Lai M-C, Chakravarty MM
Corporate AuthorsMRC AIMS Consortium
JournalCereb Cortex
Volume31
Issue7
Pagination3338-3352
Date Published2021 06 10
ISSN1460-2199
Abstract

Autism spectrum disorder (ASD) is associated with atypical brain development. However, the phenotype of regionally specific increased cortical thickness observed in ASD may be driven by several independent biological processes that influence the gray/white matter boundary, such as synaptic pruning, myelination, or atypical migration. Here, we propose to use the boundary sharpness coefficient (BSC), a proxy for alterations in microstructure at the cortical gray/white matter boundary, to investigate brain differences in individuals with ASD, including factors that may influence ASD-related heterogeneity (age, sex, and intelligence quotient). Using a vertex-based meta-analysis and a large multicenter structural magnetic resonance imaging (MRI) dataset, with a total of 1136 individuals, 415 with ASD (112 female; 303 male), and 721 controls (283 female; 438 male), we observed that individuals with ASD had significantly greater BSC in the bilateral superior temporal gyrus and left inferior frontal gyrus indicating an abrupt transition (high contrast) between white matter and cortical intensities. Individuals with ASD under 18 had significantly greater BSC in the bilateral superior temporal gyrus and right postcentral gyrus; individuals with ASD over 18 had significantly increased BSC in the bilateral precuneus and superior temporal gyrus. Increases were observed in different brain regions in males and females, with larger effect sizes in females. BSC correlated with ADOS-2 Calibrated Severity Score in individuals with ASD in the right medial temporal pole. Importantly, there was a significant spatial overlap between maps of the effect of diagnosis on BSC when compared with cortical thickness. These results invite studies to use BSC as a possible new measure of cortical development in ASD and to further examine the microstructural underpinnings of BSC-related differences and their impact on measures of cortical morphology.

DOI10.1093/cercor/bhab015
Alternate JournalCereb Cortex
PubMed ID33693614
PubMed Central IDPMC8196259
Grant ListG0701919 / MRC_ / Medical Research Council / United Kingdom
ZIA MH002949 / ImNIH / Intramural NIH HHS / United States
400061 / MRC_ / Medical Research Council / United Kingdom
MOP-106582 / / CIHR / Canada
MOP119541 / / CIHR / Canada
MOP-142379 / / CIHR / Canada
GSB 171373 / / CIHR / Canada