Current opinion: Racial and ethnic health disparities in multiple sclerosis: considering the social determinants of health.

PURPOSE OF REVIEW: We discuss racial and ethnic disparities in multiple sclerosis (MS), outcomes, and social determinants of health (SDoH). We also provide essential considerations needed to bridge the gap in inequalities, including broader representation of racial and ethnic people in clinical trials and research in general and the inclusion of better measures of living conditions. RECENT FINDINGS: The incidence and prevalence of MS have become more diverse in the USA. There is increased recognition that racial and ethnic health disparities and inequities exist due to adverse social conditions. Clinical trials have failed to be inclusive and diverse. Training in health disparity is an essential priority of funding sources, and designing clinical trials that consider the barriers these populations face can close significant gaps. SUMMARY: The incidence, prevalence, and awareness of MS have seen an incline in diverse racial and ethnic populations. Health disparities exist in MS with Black, Hispanic, and indigenous populations appearing to have worse outcomes. SDoH play a significant role in causing these health disparities. Accessibility to clinical trials and treatment are barriers these populations face. Strategic and earnest interventions considering SDoH are critically needed to develop solutions that collectively improve health and MS care for all.

Dimethyl Fumarate Delays Multiple Sclerosis in Radiologically Isolated Syndrome.

OBJECTIVE: The radiologically isolated syndrome (RIS) represents the earliest detectable pre-clinical phase of multiple sclerosis (MS). This study evaluated the impact of therapeutic intervention in preventing first symptom manifestation at this stage in the disease spectrum. METHODS: We conducted a multi-center, randomized, double-blinded, placebo-controlled study involving people with RIS. Individuals without clinical symptoms typical of MS but with incidental brain MRI anomalies consistent with central nervous system (CNS) demyelination were included. Within 12 MS centers in the United States, participants were randomly assigned 1:1 to oral dimethyl fumarate (DMF) 240 mg twice daily or placebo. The primary endpoint was the time to onset of clinical symptoms attributable to a CNS demyelinating event within a follow-up period of 96 weeks. An intention-to-treat analysis was applied to all participating individuals in the primary and safety investigations. The study is registered at ClinicalTrials.gov, NCT02739542 (ARISE). RESULTS: Participants from 12 centers were recruited from March 9, 2016, to October 31, 2019, with 44 people randomized to dimethyl fumarate and 43 to placebo. Following DMF treatment, the risk of a first clinical demyelinating event during the 96-week study period was highly reduced in the unadjusted Cox proportional-hazards regression model (hazard ratio [HR] = 0.18, 95% confidence interval [CI] = 0.05-0.63, p = 0.007). More moderate adverse reactions were present in the DMF (34 [32%]) than placebo groups (19 [21%]) but severe events were similar (DMF, 3 [5%]; placebo, 4 [9%]). INTERPRETATION: This is the first randomized clinical trial demonstrating the benefit of a disease-modifying therapy in preventing a first acute clinical event in people with RIS. ANN NEUROL 2023;93:604-614.

The impact of medical insurance on health care access and quality for people with multiple sclerosis in the United States: A scoping review.

BACKGROUND: In the United States, health insurance coverage and quality mediate access to health care, a key social determinant of health. OBJECTIVE: To perform a scoping review regarding the impact of insurance coverage and benefit design on health care access and both clinical and quality of life outcomes in people with MS (pwMS). METHODS: Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews (PRISMA-ScR) guidelines were followed. A literature search was conducted from January 2010 to February 2022. Included studies were in English, peer-reviewed, US-based, and evaluated elements of insurance and their relationship with access and quality outcomes for adult pwMS. RESULTS: Our search identified 1619 articles, of which 32 met inclusion criteria. Privately insured pwMS were more likely to be on disease-modifying therapy (DMT). Increased out-of-pocket spending was associated with lower DMT adherence and greater discontinuation rates. Access to specialty pharmacy programs was associated with improved DMT adherence. CONCLUSION: Health insurance coverage and design strongly influences health care for pwMS in the United States and may be a modifiable social determinant of health. Increased pharmaceutical cost-sharing is associated with declines in DMT utilization and adherence. Further study is needed to better characterize the impacts of other core elements of health insurance, including prior authorization requirements and step therapy.

Inclusion of optic neuritis in dissemination in space improves the performance of McDonald 2017 criteria in Hispanic people with suspected multiple sclerosis.

BACKGROUND: Hispanic people compared to White people with multiple sclerosis (MS) are two times more likely to present with optic neuritis (ON). ON in dissemination in space (DIS) after a single attack is not part of the current McDonald 2017 criteria. OBJECTIVE: To evaluate if adding ON in DIS (ON-modified criteria) improves the performance of the McDonald 2017 criteria in the diagnosis of MS after a single attack of ON. METHODS: Retrospective study of 102 patients of Hispanic background. Cases were reviewed between 2017 and 2021. Clinical ON was reported for 35 cases. ON in DIS was verified for 28 patients via MRI, optical coherence tomography, and/or visual evoked potential. We investigated the performance of the McDonald 2017 criteria and ON-modified criteria and calculated sensitivity, specificity, positive and negative predictive values, and accuracy. RESULTS: The ON-modified criteria significantly improved the performance of the McDonald 2017 criteria (p = 0.003) and identified an additional nine patients. Both sensitivity and accuracy increased from 64% to 74% and 62% to 71%, respectively, while specificity remained unchanged (40% (95% confidence interval (CI): 0.10, 0.70)). CONCLUSION: This study provides evidence that the inclusion of ON in DIS improved the overall performance of the McDonald 2017 criteria among Hispanic people.

Enhancing diversity of clinical trial populations in multiple sclerosis.

BACKGROUND: Demographic characteristics, social determinants of health (SDoH), health inequities, and health disparities substantially influence the general and disease-specific health outcomes of people with multiple sclerosis (MS). Participants in clinical trials do not represent all people with MS treated in practice. OBJECTIVE: To provide recommendations for enhancing diversity and inclusion in clinical trials in MS. METHODS: We held an international workshop under the Auspices of the International Advisory Committee on Clinical Trials in MS (the "Committee") to develop recommendations regarding diversity and inclusivity of participants of clinical trials in MS. Workshop attendees included members of the Committee as well as external participants. External participants were selected based on expertise in trials, SDoH, health equity and regulatory science, and diversity with respect to gender, race, ethnicity, and geography. RESULTS: Recommendations include use of diversity plans, community engagement and education, cultural competency training, biologically justified rather than templated eligibility criteria, adaptive designs that allow broadening of eligibility criteria over the course of a trial, and logistical and practical adjustments to reduce study participant burden. Investigators should report demographic and SDoH characteristics of participants. CONCLUSION: These recommendations provide sponsors and investigators with methods of improving diversity and inclusivity of clinical trial populations in MS.

Internuclear Ophthalmoplegia Characterizes Multiple Sclerosis Rather Than Neuromyelitis Optica Spectrum Disease.

BACKGROUND: Neuromyelitis optica spectrum disease (NMOSD) and multiple sclerosis (MS) share clinical presentations including optic neuritis and brainstem syndromes. Internuclear ophthalmoplegia (INO) is characterized by slowed ipsilateral adduction saccades and results from a lesion in the medial longitudinal fasciculus (MLF). Although INO is a common clinical finding in MS, its prevalence in NMOSD is unknown. The objective of this work is to determine the comparative frequencies of INO in patients with NMOSD and MS and compare clinical features of both disease processes. METHODS: This is a retrospective study of patients 18 years and older who have an established diagnosis of NMOSD or MS and were evaluated by both neuro-ophthalmology and neuro-immunology specialists between 2014 and 2020. Electronic medical records were screened for documentation of an acute INO at any time during follow-up. Incidence rates were calculated from number of cases of new-onset INO and patient years observed. Logistic regression was used to evaluate the likelihood of developing an INO at any time point for NMOSD vs MS patients. Multivariable analysis was performed by adjusting for age, race, gender, and length of follow-up. RESULTS: Two hundred eighty patients (80 NMOSD, 200 MS) were included. Age range was 18-79 years with a mean age of 35.14 (SD ± 12.41 years). Average length of follow-up in MS and NMOSD patients was 4.18 years vs 3.79 years, respectively (P > 0.05), and disease duration before the start of the study in MS and NMOSD was 8.76 years vs 4.65 years, respectively (P < 0.01). Mean disease duration and follow-up time of both groups was 7.58 years and 4.07 ± 2.51 years, respectively. NMOSD patients were predominantly seropositive for AQP4 antibody (61.25%, n = 49). Individuals who had MOG antibody but also met NMOSD criteria were also included (18.75%, n = 15). The frequency of INO at any time point was 1.25% (n = 1) in NMOSD compared with 16% (n = 32) in MS. The incidence rate of new-onset INO in NMOSD (excluding MOGAD) was 3.8/1,000 person years and 23.9/1,000 person years in MS. Adjusted analysis showed that NMOSD patients were 13.89 times (odds ratio [OR] 0.07, 95% confidence interval [CI] 0.01-0.598, P = 0.015) less likely to develop an INO compared with those with MS when including MOGAD patients, 12.5 times less likely (OR 0.08, 95% CI: 0.10-0.67, P = 0.02) when excluding MOGAD patients and 9.62 times less likely (OR 0.10, 95% CI: 0.01-0.87, P = 0.036) for AQP4+ patients. CONCLUSIONS: Our study shows that the incidence of new INO (3.8 vs 23.9 per 1,000 person years), and the odds of having INO at any time point are significantly lower in NMOSD than MS. This suggests that INO and consequently MLF lesions are less common in NMOSD. The presence of an INO may help in the differentiation of NMOSD from MS and may aid in earlier implementation of disease appropriate therapy.

Clinical and MRI characteristics of multiple sclerosis in patients of Middle Eastern and North African ancestry residing in Ontario, Canada.

BACKGROUND: Multiple sclerosis (MS) incidence is rising in traditionally low-burden regions, including the Middle East and North Africa (MENA). OBJECTIVES: Our objective was to evaluate disease characteristics in MS patients of MENA descent (MENA-MS). METHODS: MENA-MS patients and age- and sex-matched MS patients of European descent (EUR-MS) were identified through the MS Clinic Registry of St. Michael's Hospital in Toronto, Canada. Disease activity and severity were evaluated by the annualized relapse rate (ARR), magnetic resonance imaging (MRI) activity, change in the Expanded Disability Status Scale (EDSS), progression index (PI), and MS Severity Score (MSSS). RESULTS: All MS patients within the registry identified to be of MENA origin (n = 192), and age- and sex-matched EUR-MS patients were included. Mean age was 42.9 years, 67% female. A total of 25% and 24% of EUR-MS and MENA-MS had progressive disease, with similar mean disease durations (11.5 and 11.4 years, respectively). Clinical and radiological disease activity (ARR, proportion with new/enlarging MRI lesions) was similar. MENA-MS showed greater disability progression over time (EDSS change = 0.24 vs. 0.06, p = 0.01), a higher MSSS (3.12 vs. 2.67, p = 0.04), and higher PI (0.34 vs. 0.27, p = 0.07). CONCLUSION: MENA-MS patients demonstrate higher disease severity compared to EUR-MS patients, despite having similar inflammatory measures of disease activity, with disability progression in the absence of relapses. These observations illustrate the importance of the intersections of environmental, socioeconomic, and genetic determinants in optimizing individualized MS care.

Hypertension and hypertension severity in Hispanics/Latinx with MS.

BACKGROUND: Vascular comorbidities (VCs) including hypertension (HTN) are associated with worse multiple sclerosis (MS) outcomes. HTN is common in Latinx, but the prevalence and relationship with disability are unknown in Latinx with MS. METHODS: Latinx (n = 451) from the Alliance for Research in Hispanic MS (ARHMS) seen between 2007 and 2019 were included. HTN, diabetes (DM), hyperlipidemia (HLD), ischemic events, and smoking were considered VC. Blood pressures (BPs) were classified using the American Heart Association (AHA) criteria. Logistic regression determined associations between VC and ambulatory disability accounting for age, sex, and disease duration. RESULTS: Medical comorbidities were found in 41.9% and VC in 24.2%. Smoking (13.6%) and HTN (7.3%) were the most common. HTN was the most common over the age of 40 (12.6%). The odds of having severe disability were three times higher for those with HTN (odds ratio [OR], 3.12; 95% confidence interval (CI), 1.37-7.12). Stage II HTN according to AHA also tripled the odds (OR, 2.89; 95%CI, 1.11-7.55). AHA BP confirmed HTN in 27.5% (compared to 7.3% with established diagnosis). CONCLUSION: HTN diagnosis and stage II HTN defined by AHA were independently associated with severe ambulatory disability in Latinx with MS. HTN was underdiagnosed. Future studies should assess whether HTN treatment control would prevent disability in MS.

Race and ethnicity on MS presentation and disease course.

Multiple sclerosis (MS) has a strong racial and ethnic component and disproportionately affects whites of European background. Recent incidence reports suggest an increasing rate of MS among African Americans compared with whites. Despite this recent increase in MS in African Americans, Hispanics and Asians are significantly less likely to develop MS than whites of European ancestry. MS-specific mortality trends demonstrate distinctive disparities by race/ethnicity and age, suggesting that there is an unequal burden of disease. Inequalities in health along with differences in clinical characteristics that may be genetic, environmental, and social in origin may be contributing to disease variability and be suggestive of endophenotypes. The overarching goal of this review was to summarize the current understanding on the variability of disease that we observe in selected racial and ethnic populations: Hispanics and African Americans. Future challenges will be to unravel the genetic, environmental, and social determinants of the observed racial/ethnic disparities.

Multiple Sclerosis Mortality by Race/Ethnicity, Age, Sex, and Time Period in the United States, 1999-2015.

BACKGROUND: Multiple sclerosis (MS) carries high morbidity and shortens life span. While there is recent recognition of other US minority populations such as blacks and Hispanics being affected with MS, examination of MS-specific mortality trends by race/ethnicity has been lacking. OBJECTIVE: To investigate MS mortality rates and trends in the United States by sex, age, and race/ethnicity. METHODS: We used the Compressed Mortality data file for 1999-2015 in the Wide-ranging online Data for Epidemiological Research system developed by the Center for Disease Control and Prevention to calculate the age-adjusted (US 2000 standard population) and age-specific MS mortality rate (per 100,000) by race/ethnicity and sex over time. Five mutually exclusive racial/ethnic groups were included in the analysis: non-Hispanic (NH) white, NH black, NH Asian or Pacific Islander (API), NH American Indian or Alaska Native, and Hispanic. RESULTS: The average annual age-adjusted MS mortality rate was highest among NH whites (0.90 for males and 1.50 for females) immediately followed by NH blacks (0.75 for males and 1.42 for females), and lowest among APIs (0.05 for males and 0.12 for females). Statistically significant, increasing trend in age-adjusted MS mortality was observed during 1999-2015 among NH whites and NH blacks regardless of sex, more substantially in the latter. Age-specific MS mortality patterns showed NH blacks had the highest rate under age 55 and NH whites had the highest rate after that age point. For these 2 groups, MS mortality increased with age in both sexes and peaked at ages 55-64 for NH blacks and 65-74 for NH whites before declining substantially, while for Hispanic and API groups the risk plateaued after age 55. CONCLUSION: MS-specific mortality trends demonstrate distinctive differences by race/ethnicity and age. The observations that whites and females are more likely to die from MS is in line with the overall understanding that these groups are affected more by MS. However, the findings of blacks dying at an earlier age and having more substantially increasing mortality trends than whites suggest that MS burden weighs unequally by race. Further investigation into these trends may provide additional evidence into risk or protective factors within each group.

Pregnancy and fetal outcomes following natalizumab exposure in pregnancy. A prospective, controlled observational study.

BACKGROUND: Safety data on first-trimester natalizumab exposure are scarce, as natalizumab is usually withdrawn three months before pregnancy. OBJECTIVE: The objective of this paper is to investigate the fetal safety of exposure to natalizumab (Tysabri(®)) during the first trimester of pregnancy using disease-matched (DM) and healthy control (HC) comparison groups. METHODS: A total of 101 German women with RRMS exposed to natalizumab during the first trimester of pregnancy were identified. Birth outcomes in the exposed group were compared to a DM group (N = 78) with or without exposure to other disease-modifying drugs, and an HC group (N = 97). RESULTS: A total of 77, 69 and 92 live births occurred in the Exposed, DM and HC groups, respectively. The rates of major malformations (p = 0.67), low birth weight (<2500 grams) (p = 1.0) and premature birth (p = 0.37) did not differ among groups. Higher miscarriage rates (p = 0.002) and lower birth weights (p = 0.001) occurred among the Exposed and DM groups, as compared to the HC; however, there was no significant difference between the Exposed and DM groups. CONCLUSION: Exposure to natalizumab in early pregnancy does not appear to increase the risk of adverse pregnancy outcomes in comparison to a DM group not exposed to natalizumab.

Multiple sclerosis: review of eye movement disorders and update of disease-modifying therapies.

PURPOSE OF REVIEW: To review important eye movement disorders in multiple sclerosis (MS) and update the ophthalmologist on disease-modifying therapies in MS, from the perspective of expert neurologists. RECENT FINDINGS: A large study confirmed that eye movement abnormalities in MS can be commonly identified by bedside examination. Identifying such ocular motility disturbances can assist in the diagnosis and prognosis for patients with MS. Articles published on such agents as oral teriflunomide and the biologics, natalizumab and alemtuzumab, have defined emerging roles of these treatments in the management of MS. SUMMARY: Many patients with MS suffer from isolated or a combination of eye movement disorders. Understanding their ocular motility disturbance patterns can help diagnose MS and correlate with the progression of MS. Exciting advances in MS disease-modifying treatments have been developed. Patients have more options than ever before of injectable, infusion and oral therapies. The therapeutic efficacy in lowering relapse rates is counterbalanced by these drugs' side-effects.

Tuberculous Meningitis or Neurosarcoidosis-a Diagnostic Quandary. From the National Multiple Sclerosis Society Case Conference Proceedings

Distinguishing granulomatous diseases remains diagnostically challenging. Clinical phenotypes and neuroimaging findings resemble many infectious and noninfectious disorders. We describe a Hispanic/Latino man diagnosed with tuberculous meningitis who deteriorated neurologically after treatments. Additional workup revealed a pathology more consistent with neurosarcoidosis. Care access delays and social circumstances likely complicated his diagnosis.

Disparities by Race in Pregnancy Care and Clinical Outcomes in Women With Multiple Sclerosis: A Diverse Multicenter Cohort

BACKGROUND AND OBJECTIVES: Racial disparities exist in both neurologic and obstetric populations, underscoring the importance of evaluating pregnancy outcomes in diverse women with multiple sclerosis (MS). The objective of this multicenter retrospective study was to compare pregnancy care and outcomes between Black and Hispanic (underrepresented) and White women with MS. METHODS: Demographic and clinical data were extracted from medical records of 9 US MS centers for women with MS/clinically isolated syndrome who delivered live births between 2010 and 2021. Sites identified at last 15 consecutive Black/Hispanic women and a matching number of White women. Socioeconomic factors, pregnancy, and MS care/outcomes were compared between groups (underrepresented and White and then Black and Hispanic) using Wilcoxon rank sum (U statistic and effect size r reported), χ2, t tests and logistic regressions as appropriate to data type. Multiple imputation by chained equation was used to account for missing data. RESULTS: Overall, 294 pregnancies resulting in live births were analyzed ( 81 Black, 67 Hispanic, and 146 White mothers). Relative to underrepresented women, White women lived in areas of higher median (interquartile range [IQR]) Child Opportunity Index (79 [45.8] vs 22 [45.8], U = 3,824, r = 0.56, p < 0.0001) and were more often employed (84.9% vs 75%, odds ratio [OR] 2.57, CI 1.46-4.50, p = 0.0008) and privately insured (93.8% vs 56.8%, OR 11.6, CI 5.5-24.5, p < 0.0001) and more received a 14-week ultrasound (98.6% vs 93.9%, OR 4.66, CI 0.99-21.96, p = 0.027). Mode of delivery was significantly different between the three groups (X2(10,294) = 20.38, p = 0.03); notably, Black women had the highest rates of emergency cesarean deliveries, and Hispanic women highest rates of uncomplicated vaginal deliveries. Babies born to underrepresented women had lower median (IQR) birthweights than babies born to White women (3,198 g [435.3 g] vs 3,275 g [412.5 g], U = 9,255, r = 0.12, p = 0.04) and shorter median (IQR) breastfeeding duration (4.5 [3.3] vs 6.0 [4.2] months, U = 8,184, r = 0.21, p = 0.003). While underrepresented women were younger than White women (mean [SD] 30.9 [4.8] vs 33.8 [4.0], t = 1.97, CI 1.96-3.98, p < 0.0001), their median (Q1-Q3, IQR) Expanded Disability Status Scale was higher (1.5 [1-2.5, 1.5] vs 1 [0-1.5, 1.5], U = 7,260, r = 0.29, p < 0.0001) before pregnancy. Finally, medical records were missing more key data for Black women (19.7% missing vs 8.9% missing, OR 2.54, CI 1.25-5.06, p = 0.008). DISCUSSION: In this geographically diverse multicenter cohort, underrepresented women entered pregnancy with higher disability and fewer health care resources. Pregnancy represents a pivotal window where structural factors affect maternal and fetal health and neurologic trajectories; it is a critical period to optimize care and health outcomes.

Impact of adherence to disease modifying therapies on long-term clinical and economic outcomes in multiple sclerosis: A claims analysis of real-world data.

BACKGROUND: Multiple sclerosis (MS) is a chronic neurodegenerative inflammatory disease that requires long-term commitment to treatment for optimal outcomes. A variety of disease-modifying therapies (DMTs) are now available that reduce relapses and delay disease progression in people with MS. However, adherence remains a significant issue, with a variety of mental, physical, and emotional factors contributing to non-adherence. In a large number of studies, non-adherence has been associated with worse clinical outcomes (relapses and disease severity), a higher economic burden, and loss of work productivity. However, many of these studies were short-term (1-2 years) or cross-sectional studies; thus, more data are needed on the long-term clinical and economic impacts of DMT non-adherence. The objective of this study was to determine the longer-term impact of adherence to DMTs on disease activity and healthcare resource utilization (HCRU) in people with MS. The study hypothesis was that non-adherence to DMTs would be associated long-term with worse clinical outcomes and a higher economic burden. METHODS: A retrospective administrative claims analysis of the US MarketScan® Commercial database (2011-2017) in individuals (18-65 years) with MS (based on International Classification of Disease coding) was conducted. Adherence was classified by proportion of days covered (PDC) ≥0.8 and non-adherence by PDC <0.8; sensitivity analyses helped further categorize as moderately (PDC ≥0.6-<0.8) or highly (PDC <0.6) non-adherent. Cohorts were matched using propensity score matching. Time to first relapse, annualized relapse rate (ARR), time to use of assistive devices (cane/walker or wheelchair), and annual HCRU (inpatient, emergency room [ER], outpatient, and MRI visits and costs) were compared between cohorts. RESULTS: 10,248 MS cases were identified; 58% met adherence criteria, and 42% met non-adherence criteria. Mean follow-up from diagnosis or first DMT claim was 5.3 years. Adherent individuals had a longer time to first relapse (hazard ratio [HR] 0.83; 95% confidence interval [CI]: 0.77-0.90; p<0.0001), a lower ARR (0.13 vs. 0.18, respectively; rate ratio [RR] 0.75 [95% CI: 0.71-0.79]; p<0.0001), and longer lag times to cane/walker use (HR 0.79 [95% CI: 0.66-0.94]; p=0.0067) and wheelchair use (HR 0.68 [95% CI: 0.55-0.83]; p=0.0002) than non-adherent individuals. Adherent individuals had fewer annual inpatient and ER visits and lower total costs than those who were non-adherent (p<0.0001). Sensitivity analyses showed that differences in disease activity and HCRU were generally more pronounced between matched adherent and highly non-adherent pairs than between matched adherent and moderately non-adherent pairs. CONCLUSION: Significant differences in MS disease activity and HCRU were observed based on adherence to DMTs. Our study underscores the negative impact of non-adherence to DMTs on long-term clinical and economic outcomes in MS.

Multiple sclerosis in Indigenous Peoples of the Americas: A systematic review of incidence, prevalence, and outcomes.

INTRODUCTION: The incidence, prevalence and outcomes of multiple sclerosis (MS) are unclear in Indigenous Peoples (IP) who are more likely to be underrepresented in research. We completed a systematic review of MS in IP of the Americas. METHODS: A systematic review was conducted using PubMed, Web of Science, and Cochrane databases as well as references of retrieved papers. Inclusion criteria were: peer-reviewed publications (January 1990- December 2021), incidence, prevalence, or clinical outcome measures of MS in self-identified IP in the Americas. Incidence, prevalence, morbidity and mortality data were summarized and stratified by location and year of publication. Study quality was evaluated by risk of bias or confounding. RESULTS: Out of 416 titles, thirteen studies met inclusion criteria. Four studies evaluated incidence, seven prevalence, three clinical outcomes and one mortality. Most studies were completed in Canada or the United States (US). Incidence rates per 100,000 ranged from 0.48 (in US Indian Health Service records) to 8.15 (First Nations Manitoban Canadians). Prevalence ranged from 0 (Lacandonian Mexicans and Panamanians) to 188.5 (First Nations Manitoban Canadians). Incidence and prevalence are consistently lower in IP than comparator White populations. IP with MS were reported to have higher disability and faster disability progression than non-Indigenous comparators. MS-related mortality is low compared to White people. CONCLUSION: There is an absence of high-quality studies evaluating MS in IP. Available evidence indicates low, but increasing incidence and prevalence of MS in IP of the Americas. IP with MS may have worse disability than non-Indigenous comparators. Future studies should evaluate the factors influencing the increases in incidence and prevalence as well as better characterize possible disparities in MS care among IP.

Diversity, Equity, and Inclusion in the Multiple Sclerosis Community: A Call to Action.

Many medical organizations have begun to confront the longstanding problem of inequalities in health care delivery and the undeniable effect of disparities on health outcomes. The Consortium of Multiple Sclerosis Centers (CMSC) recognizes that disparities affect the lives of many people with multiple sclerosis (MS) and acknowledges the need to address this as an organization. The CMSC recently (1) appointed a task force, (2) conducted a survey of its membership, (3) commissioned this review article and call to action, and (4) formulated a mission statement on diversity, equity, and inclusion (DEI), which was adopted by the CMSC's Board of Governors in March 2023. This paper summarizes recent literature on health care disparities in MS, particularly those relating to race/ethnicity, sexual orientation, and gender identity. It presents findings from CMSC's survey of members' awareness of DEI issues, the need for education and resources for MS care providers, and existing institutional policies on DEI in the members' practice settings. It also presents the task force's recommendations for next steps, which includes the goal of greater diversity in the MS workforce of the future. The CMSC will continue to revisit DEI policies and practices over time with the goal of motivating greater awareness, momentum, and positive changes within the MS community.

Health Disparities Research Curricula and Training Development: Recommendations From a National Institute of Neurological Disorders and Stroke Workgroup.

The national mandate to improve health equity in the United Sates is advancing. Racial and ethnic disparities in various aspects of health care have been clearly delineated, and sources of such disparities have been identified. However, implementing solution-focused interventions to eradicate such disparities, thereby achieving health equity in all US communities, has remained a daunting challenge, and no area more so, than with neurologic diseases. To assure success with bridging prominent disparities in neurologic outcomes, the pipeline of neurologic disparities researchers needs to be broadened, numbers of mid-career and senior disparities scientists sustained, partnerships with community stakeholders enhanced, incentivization of academic organizations pursued, education of all neurologic researchers conducted, and exemplary training of funding agency staff prioritized. To improve the current state of neurologic disparities, the National Institute of Neurological Disorders and Stroke assembled a working group of its advisory council. (2020-2022) to examine the state of health disparity training and research. Through consensus building, we present identified gaps and recommendations to the current state of underrepresented groups in medicine in health disparity research and its training and curricula in the United States.

Understanding humoral immunity and multiple sclerosis severity in Black, and Latinx patients.

People identified with Black/African American or Hispanic/Latinx ethnicity are more likely to exhibit a more severe multiple sclerosis disease course relative to those who identify as White. While social determinants of health account for some of this discordant severity, investigation into contributing immunobiology remains sparse. The limited immunologic data stands in stark contrast to the volume of clinical studies describing ethnicity-associated discordant presentation, and to advancement made in our understanding of MS immunopathogenesis over the past several decades. In this perspective, we posit that humoral immune responses offer a promising avenue to better understand underpinnings of discordant MS severity among Black/African American, and Hispanic/Latinx-identifying patients.