Multiple sclerosis affects approximately 400,000 people across the United States and over 2 million people worldwide. [Munoz-Culla 2013; Buchanan 2011] Symptoms of MS include focal signs such as weak motor and sensory deficits, visual disorders, spasticity, bladder and bowel dysfunction, and dysphagia, as well as generalized symptoms, including depression, pain, cognitive difficulties, and fatigue. [Kahn 2015] While the onset of disease is typically between the ages of 20 and 50 years of age, the average age of onset is 34 years. Although the cause of MS is still unknown, it is believed to be associated with both genetic and environmental factors. While there is no cure for MS, there are therapies available to help alleviate symptoms and modify the disease course.
Although MS has classically been thought of as a disease that primarily affects white non-Hispanics, but the myth that black people don’t get MS is being debunked. In multiple studies, African Americans have been found to have an increased incidence of MS, with one study finding that blacks had a 47% increased risk, as compared with whites. [Deussing 2012; Wallin 2012; Langer-Gould 2013] This misperception may possibly be tied to the lack of representation of African Americans in large studies of MS. Khan and colleagues found that out of 60,000 published articles on MS, only 113 focused on African Americans. [Kahn 2015]
African American MS patients have also been found to have differing disease progression and severity, as compared to white patients with MS. African Americans are more likely to have an older age at disease onset. [Cree 2009] Once the disease is diagnosed, African Americans are found to have more severe disease and to experience more frequent relapses. This subgroup also experiences greater disability from MS, requiring ambulatory assistance earlier in their disease course and have been found to be admitted to nursing homes at a younger age than Caucasians with MS. [Amezcua 2011; Marrie 2006; National MS Society 2018; Kister 2010] African Americans have also been found to die from MS at a younger age than their white counterparts. [Amezcua 2018]
Once MS has been diagnosed, it can be categorized into four basic types, commonly called phenotypes, which include clinically isolated syndrome, relapsing remitting, secondary progressive and primary progressive. These four phenotypes refer both to symptoms experienced by the patient and to the approximate disease course that patients follow. African Americans have higher rates of primary progressive subtype and lower rates of the more common relapsing remitting phenotype. African Americans are also more likely to present with opticospinal MS, which is a distinct form of MS restricted to the optic nerves and spinal cord and are more likely to experience acute optic neuritis and transverse myelitis. These variations in clinical presentation and disease progression found among patients with MS have suggested that there are fundamental differences in both the clinical phenotype and the natural history of the disease among African Americans. [Naismith 2016; Cree 2009; Cree 2014]
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