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.

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.

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.

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.

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.