Compared to the general population, patients with newly diagnosed multiple sclerosis (MS)/clinically isolated syndrome (CIS) are more likely to have impaired cognitive function, a study in Neurology suggests. The study also found that being black and Hispanic, not having a university degree, and having a relatively low household income are predictors of cognitive performance.
A total of 1174 adults with MS/CIS (mean age, 40.7 years) who were enrolled in the MS Sunshine Study were included in this analysis. The researchers administered the oral Symbol Digit Modalities Test (SDMT) during a structured in-person assessment to identify cognitive impairment in incident cases of MS/CIS (n=554) and matched controls (n=620). Additionally, verbal fluency was also determined. A multivariable linear regression was used to examine the association between SDMT scores and race/ethnicity and MS. Multivariable analyses were adjusted for age at time of interview, sex, education, and household income.
Across all racial/ethnic groups, patients with MS/CIS had significantly lower mean SDMT scores compared to controls (52.2 vs 58.3, respectively; P <.0001). The multivariable linear regression analyses, independent predictors of lower oral SDMT scores included being black (β,−5.97; P <0.0001) or Hispanic (β,−3.06; P <0.0001), having MS (β,−6.04; P <.0001), lower educational attainment (high school, trade school, or less: β,−5.02; P <.0001), and having a household income ≤$65,000 (β,−5.02; P =.0007). The researchers observed no interaction between MS case status and race/ethnicity on SDMT scores.
The authors note that these analyses may have been limited by the inclusion of only participants from California and the lack of ethnic diversity among the black and Hispanic participants.
The investigators suggest that in addition to optimizing disease-modifying treatments to slow cognitive decline in patients with MS, interventions aimed at improving cognition may also be beneficial. “From a societal perspective, improving opportunities for higher educational attainment and higher incomes for black and Hispanic participants in the United States would likely reduce racial/ethnic disparities in cognitive performance.”
Disclosure: Several study authors declared affiliations with the pharmaceutical industry. Please see the original reference for a full list of authors’ disclosures.
Reference
Amezcua L, Smith JB, Gonzales EG, Haraszti S, Langer-Gould A. Race, ethnicity, and cognition in persons newly diagnosed with multiple sclerosis [published online March 9, 2020]. Neurology. doi: 10.1212/WNL.0000000000009210
