Douglas C Dean, III, PhD – Slide of the Week

Douglas C Dean, III, PhD - Slide of the Week

Title: Gray matter microstructure differences in autistic males: A gray matter based spatial statistics study

Citation: DiPiero, M. A., Surgent, O. J., Travers, B. G., Alexander, A. L., Lainhart, J. E., & Dean Iii, D. C. (2023). Gray matter microstructure differences in autistic males: A gray matter based spatial statistics study. NeuroImage. Clinical, 37, 103306.

Legend: GBSS NODDI Neurite Density Index (FICVF) Age-by-Group Interactions. GBSS analysis showed significant (p < 0.05, FWER- corrected) age-by-group interactions on FICVF in the right hemisphere middle frontal gyrus, precentral gyrus, and frontal pole with greater age-related increases in FICVF observed in the ASD group compared to TD group. Brain images on the right show neuroanatomical locations and level of significance in which the age-by-group interaction model was found to be significant. Scatter plots represent mean FICVF values of significant voxels from each individual.

Abstract: Background – Autism spectrum disorder (ASD) is a complex neurodevelopmental condition. Understanding the brain’s microstructure and its relationship to clinical characteristics is important to advance our understanding of the neural supports underlying ASD. In the current work, we implemented Gray-Matter Based Spatial Statistics (GBSS) to examine and characterize cortical microstructure and assess differences between typically developing (TD) and autistic males. Methods – A multi-shell diffusion MRI (dMRI) protocol was acquired from 83 TD and 70 autistic males (5-to-21-years) and fit to the DTI and NODDI models. GBSS was performed for voxelwise analysis of cortical gray matter (GM). General linear models were used to investigate group differences, while age-by-group interactions assessed age-related differences between groups. Within the ASD group, relationships between cortical microstructure and measures of autistic symptoms were investigated. Results – All dMRI measures were significantly associated with age across the GM skeleton. Group differences and age-by-group interactions are reported. Group-wise increases in neurite density in autistic individuals were observed across frontal, temporal, and occipital regions of the right hemisphere. Significant age-by-group interactions of neurite density were observed within the middle frontal gyrus, precentral gyrus, and frontal pole. Negative relationships between neurite dispersion and the ADOS-2 Calibrated Severity Scores (CSS) were observed within the ASD group. Discussion –  Findings demonstrate group and age-related differences between groups in neurite density in ASD across right-hemisphere brain regions supporting cognitive processes. Results provide evidence of altered neurodevelopmental processes affecting GM microstructure in autistic males with implications for the role of cortical microstructure in the level of autistic symptoms. Conclusion – Using dMRI and GBSS, our findings provide new insights into group and age-related differences of the GM microstructure in autistic males. Defining where and when these cortical GM differences arise will contribute to our understanding of brain-behavior relationships of ASD and may aid in the development and monitoring of targeted and individualized interventions.

About the Lab: Doug’s research in the Developing Brain Imaging Lab, focuses on the development and application of novel quantitative magnetic resonance imaging (MRI) methods to measure and evaluate the brain structure throughout early neurodevelopment and aging. He is particularly experienced in pediatric imaging, scanning more than 800 infants and young children (3 months to 12 years) during his graduate work. His current research is focused on examining how the white matter microstructure of the brain develops across the early development and how these microstructural processes are related to changes in cognition and behavior.

Investigator: Doug Dean III, PhD

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