Don't Dismiss MS in the Differential Diagnosis for Minorities, Experts Warn

Pauline Anderson

March 01, 2023

SAN DIEGO ― Experts are leading a new initiative to drive home the message that clinicians must consider multiple sclerosis (MS) in the differential diagnosis of Black patients and those of other minorities who present with symptoms of demyelination.

Dr Lilyana Amezcua

One of the biggest barriers to accurately diagnosing MS in non-White patients is the "bias that MS does not affect these populations" or is less common, Lilyana Amezcua, MD, associate professor of neurology, Keck School of Medicine, University of Southern California, San Diego, told Medscape Medical News.

"Clinicians should definitely consider MS and not exclude it based on data supporting that MS is most common in Whites and those of European backgrounds," she added.

Amezcua is part of a task force on the differential diagnosis in MS that was convened by the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) to provide insight into factors to consider when encountering underrepresented populations.

She discussed the initiative here at the Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2023.

Delayed Diagnosis

Increased migration has resulted in more diversity in once predominantly White countries in which MS is highly prevalent, including the US, Canada, Northern Europe, and Australia, said Amezcua.

"MS should be considered in anyone irrespective of race and ethnicity who is presenting with a clinical demyelination syndrome," said Amezcua.

Black, Hispanic, East Asian and Middle Eastern populations are particularly vulnerable to diagnostic errors and delays, said Amezcua. Excessive reliance on "typical expectations and presentations" may explain this phenomenon, she said.

Delays in diagnosis can have a major impact, she said. She noted that to prevent disability requires rapid diagnosis and early administration of disease-modifying treatments.

Amezcua reviewed some differences in clinical characteristics of MS in underrepresented populations. For example, Hispanic and Black people are twice as likely to present with optic neuritis or transverse myelitis.

In addition, the age at symptom onset appears to vary. Among White patients, the average age of onset is 32.8 years, vs 28.6 years in Black, Asian, and Middle Eastern people.

Variation in Diagnostic Markers

Data also suggest that MS type may differ in these non-White populations. For example, said Amezuca, primary progressive and secondary progressive MS are more common in Black individuals compared with White patients.

There are also variations in cerebrospinal fluid markers, with some research showing higher IgG index and synthesis levels in Black patients. One study reported that an abnormal IgG index was more common among Hispanic patients than among White patients.

Amezcua also noted that physicians should be aware of the structural and social factors that can affect the diagnosis of MS in underrepresented populations.

In a separate presentation, Amezcua spoke on social determinants of health, which include healthcare access, economic stability, education, and neighborhood environment. She said these determinants "are shaped by the distribution of power, money and resources."

Those who are socially and economically disadvantage are at risk for worse health outcomes. Disadvantaged patients with MS face high drug costs, including steep copays, said Amezcua. She noted that high out-of-pocket costs for therapies contribute to poor adherence to treatment.

She cited research showing that disadvantaged individuals also have higher utilization rates for emergency departments and less access to specialist care. One study showed that Black and Hispanic patients with MS are 30% to 40% less likely to access specialty care.

Amezcua noted the importance of understanding and acknowledging these disadvantages and that engaging community leaders can help to develop strategies to address these disparities.

"Addressing social determinants of health and health disparities can reduce the burden of living with MS," she said.

Amezcua said she and her colleagues are "making progress" and are collecting more data and that clinicians should "eventually understand that MS is a global disease."

"Implicit Bias"

Commenting for Medscape Medical News, Andrew J. Solomon, MD, associate professor, Department of Neurological Sciences and chief of the Division of Multiple Sclerosis, University of Vermont, said that for years, the "prevailing thought" was that MS was less common in underrepresented populations.

"We thought alternative diagnoses that could mimic MS were more common," said Solomon.

That mindset can lead to "implicit bias" that affects which diagnoses clinicians consider most likely when seeing a new patient for MS evaluation, he said.

Recent data show that the incidence of MS may not vary by race or ethnicity "as much as we thought," said Solomon. "The risk of MS in Black patients in the US may be similar to that of White patients."

But lack of awareness among providers about these emerging data may mean unnecessary diagnostic delays for underrepresented patients, said Solomon.

In addition to education, more research is needed to "explore the diagnostic pathway" experienced by underrepresented patients with MS that might reveal more about "key barriers to accurate and timely diagnosis," said Solomon.

Addressing those barriers "may require both educational and system-level interventions," he said.

Amezcua and Solomon have disclosed no relevant financial relationships.

Americas Committee for Treatment and Research in Multiple Sclerosis (ACTRIMS) Forum 2023: Session on MS Differential Diagnosis, presented February 23, 2023; and session 6.4 (social determinants), presented February 25, 2023

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