The Global Burden of MS: Moving Forward with Epidemiology, Early Diagnosis and Efficacious Treatment
Multiple sclerosis (MS) is the most common neurodegenerative disease of young adults worldwide and has been more frequently encountered in non-Western countries in recent years. Updates on the epidemiology, diagnosis and treatment of MS show both progress and gaps to address.
The MS International Federation estimates 2.8 million people were living with MS worldwide in 2020 (prevalence: 35.9 per 100,000 population). Since 1990, the prevalence of MS has increased in every major world region. Incidence of MS has been more stable, with selective increases for some geographic regions and demographic groups. Unfortunately, large data gaps exist for both MS prevalence and incidence in many world regions including sub-Saharan Africa, Asia, and Oceana. High-quality epidemiologic data are needed in these understudied regions to improve our understanding of MS risk factors, improve resource allocation, and support health policy and advocacy efforts.
Disparities in the diagnosis of MS in several regions of the world are related to a lack of neurological specialists and diagnostic resources (e.g., magnetic resonance imaging (MRI)) required to work-up and confirm a case of MS. The 2017 McDonald MS diagnostic criteria is the gold standard and allows one to make an early diagnosis after first symptom onset with the assistance of MRI and other paraclinical testing. Having access to MRI is critical for confirming a diagnosis. Equally important is a consistent brain MRI protocol that allows for the detection of new brain lesions over time and for easy comparison of MRIs for patients who move between cities or countries. To meet this need, North American and European imaging experts recently published a new standardized MS MRI protocol for optimal diagnosis, prognosis, and monitoring of patients with MS.
An explosion of MS disease modifying therapies (DMTs) has occurred over the past three decades, with most medications targeting the early inflammatory phase of the disease. Relapses and MRI lesions can be controlled for the majority of patients with relapsing forms of MS with the current choices. Based on a recent review, disability progression of MS in Latin America, Africa, Asia, and the Middle East have similarities to Western MS. In some regions and subpopulations, there is evidence of a more aggressive course, possibly due to a combination of genetic and environmental factors. MS neurological progression may contribute to absenteeism and presenteeism at work or loss of employment, all major non-medical costs of MS. When evaluating the direct medical burden of MS, the cost of DMTs is the most substantial, comprising 60% of all direct medical costs.
Based on the current landscape, the following steps should be initiated to address the global burden of MS. First, research studies should be funded to generate accurate data on the epidemiology of MS in locations where there is limited access to neurological care but no data or limited data. (e.g., sub-Saharan Africa). Second, increases to the pool of neurological disease specialists should be promoted where they are most needed through expanded residency training programs and targeted educational campaigns of physicians and advance practice providers. Third, educational programs for health care professionals, the public, and government policy experts should be made available about the burden, treatment, and impact of MS. Finally, access to cost-effective MS DMTs and rehabilitation care programs should be further promoted by politicians and advocacy groups. Many resources have been made available for epidemiologists, clinicians, and policy advocates involved with MS research, care, and advocacy in recent years. With a united effort, we can improve the future for those impacted by MS across the globe.
1. Walton C, King R, Rechtman L, et al. Rising prevalence of multiple sclerosis worldwide: Insights from the Atlas of MS, third edition. Mult Scler 2020;26:1816-1821.
2. GBD 2016 Multiple Sclerosis Collaborators. Global, regional, and national burden of multiple sclerosis 1990-2016: a systematic analysis for the Global Burden of Disease Study 2016. Lancet Neurol 2019;18:269-285.
3. Thompson AJ, Banwell BL, Barkhof F, et al. Diagnosis of multiple sclerosis: 2017 revisions of the McDonald criteria. Lancet Neurol 2018;17:162-173.
4. Wattjes M, Ciccarelli O, Reich D, et al. 2021 MAGNIMS-CMSC-NAIMS consensus recommendations on the use of MRI in patients with multiple sclerosis. Lancet Neurol 2021;20:653-670.
5. Disease Modifying Therapies for Multiple Sclerosis. https://www.nationalmssociety.org/Programs-and-Services/Resources/The-MS-Disease-Modifying-Medications-(-pdf).
6. Bonomi S, Jin S, Culpepper W, Wallin M. MS and Disability Progression in Latin America, Africa, Asia and the Middle East: A Systematic Review. Mult Scler Relat Disord. 2021;51:102885.
7. Bebo B, Cintina I, LaRocca N, et al. Economic Burden of Multiple Sclerosis in the United States: Estimate of Direct and Indirect Costs. Neurology. 2022;3;98:e1810-e1817.
Dr. Mitchell Wallin, MD, MPH is an Associate Professor of Neurology at the University of Maryland School of Medicine and the Director of the Veterans Affairs Multiple Sclerosis Centers of Excellence-East.