Abstract Details

Title Ethnoracial Disparities in Grey Matter Atrophy in Multiple Sclerosis Are Mediated by Structural Disconnectivity

Topic Multiple Sclerosis

Presentation(s) P9 - Poster Session 9 (11:45 AM-12:45 PM)

Poster/Presentation
Number 1-002

Objective To investigate ethnoracial disparities in grey matter (GM) atrophy in multiple sclerosis (MS), and the contribution of white matter lesions and consequent structural disconnectivity.

Background Significant ethnoracial disparities were highlighted in different MS outcomes. GM atrophy is a chief correlate of physical disability and cognitive decline in MS.

Design/Methods This retrospective study included 297 people with MS (PwMS) divided into 3 self-identified age- and sex-matched groups: 82 Non-Hispanic Black (BA), 117 Non-Hispanic White (WA), 98 Hispanic (HA) PwMS. Included subjects underwent clinical evaluation and magnetic resonance imaging at an academic MS center. We assessed GM atrophy using univariate (voxel-based morphometry) and multivariate (source-based morphometry) techniques, as well as white matter hyperintense lesion burden and distribution. Lesion distributions were used to estimate the consequent structural disconnectivity patterns. Mediation analyses explored the relationships between ethnoracial groups, white matter lesions, structural disconnectivity, and grey matter atrophy.

Results The groups did not show significant differences in disease duration (P=0.4), disability severity (P=0.3), clinical phenotype (P=0.2), or disease-modifying therapy (P=0.4). BA and HA exhibited greater global grey matter atrophy compared to WA (P=0.02), particularly in temporal, precuneus, occipital, and cingulate GM. Lesion burden was significantly higher in BA and HA compared to WA (P<0.001), and structural disconnectivity was most prominent in hippocampal, cingulate, precuneus, and deep grey matter regions. Mediation analyses showed that lesion load significantly mediated group differences in global GM atrophy (Percent mediated=52.4%), while structural disconnectivity mediated group differences notably in deep grey matter, insular, and cingulate regions.

Conclusions Significant ethnoracial disparities exist in GM atrophy and its patterns among diverse MS patients, partially mediated by white matter lesions and consequent structural disconnectivity. These findings underscore the importance of considering ethnoracial factors in MS research and clinical practice, potentially informing personalized treatment strategies and emphasizing the need for diverse representation in clinical trials.

Authors/Disclosures
Ahmed A. Bayoumi, MD (McGovern Medical School) PRESENTER	Dr. Bayoumi has nothing to disclose.
Joseph Thomas	Mr. Thomas has nothing to disclose.
John A. Lincoln, MD, PhD (McGovern Medical School, UTHealth)	The institution of Dr. Lincoln has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Sanofi-Genzyme. Dr. Lincoln has received personal compensation in the range of $5,000-$9,999 for serving on a Speakers Bureau for Biogen. The institution of Dr. Lincoln has received research support from Deaprtment of Defense. The institution of Dr. Lincoln has received research support from National Institutes of Health. The institution of Dr. Lincoln has received research support from EMD-Serono. Dr. Lincoln has received intellectual property interests from a discovery or technology relating to health care.

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