MRI scans of the same brain slice at monthly intervals reveal bright spots within the brain tissue indicating active lesions. MRI scans of participants in a recent study show that African Americans with MS had more damage to brain tissue and had less normal white and grey matter compared to whites with the disease. (Courtesy: U.S. Brookhaven National Laboratory)

U. BUFFALO (US)—Compared to Caucasians, fewer African Americans develop multiple sclerosis, but researchers say their disease progresses more rapidly and therapies are less effective.

“Black patients showed more brain tissue damage and accumulated brain lesions faster than whites, along with rapid clinical deterioration,” says Bianca Weinstock-Guttman, associate professor of neurology at the University at Buffalo School of Medicine and Biomedical Sciences.

“The results provide further support that black patients experience a more severe disease, calling for individualized therapeutic interventions for this group of MS patients.”

Magnetic resonance images (MRI) of a cohort of 567 consecutive MS patients showed that blacks with MS had more damage to brain tissue and had less normal white and grey matter compared to whites with the disease. The study was published in the journal Neurology.

“White matter,” which refers to the parts of the brain that contain nerve fibers sheathed in a white fatty insulating protein called myelin, is responsible for communication between the various grey matter regions, where nerve cells are concentrated and where cognitive processing occurs.

“Initially, multiple sclerosis was considered primary a white-matter disease,” says Weinstock-Guttman, “but today we know that the gray matter may be more affected than white matter.”

In general, black MS patients tend to have more severe and more frequent attacks, followed by an incomplete recovery even after the first episode, Weinstock-Guttman says.

Studies on signs and symptoms of MS among populations have shown that blacks experience gait problems sooner after their diagnosis, show faster cognitive decline than whites with MS, and become dependent on a wheelchair sooner, she notes.

Seventy-nine black patients and 488 white patients older than 18 participated in the study. All had been scanned within 90 days of their most recent clinical visit.

Black participants were significantly younger, and their disease was more severe than white patients, despite having MS for a shorter amount of time, Weinstock-Guttman says..

“Results of the MRI scans showed that the aggressive disease process in blacks appears to be associated with increased macroscopic and microscopic tissue damage, as measured by specific MRI parameters,” says Weinstock-Guttman.

“Based on our MRI findings, a plausible hypothesis that would explain the more aggressive disease in blacks compared to whites with MS may be that blacks have a reduced capacity for remyelination, the brain’s ability to repair the protective myelin sheath. However, to confirm this hypothesis, we will need to conduct more longitudinal studies.”

The study was supported by grants from the National Multiple Sclerosis Society and the UB Pediatric MS Center of Excellence.

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