What is multiple sclerosis?

Multiple sclerosis (MS) is a chronic autoimmune disease of the central nervous system — where the immune system attacks myelin (the protective sheath around nerve fibres), causing plaques of demyelination in the brain and spinal cord. This disrupts nerve signal transmission, causing variable symptoms: vision disturbance (optic neuritis), limb weakness, sensory disturbance, fatigue, bladder dysfunction and cognitive problems. MS affects 2.9 million people globally and is a leading cause of non-traumatic neurological disability in young adults.

What are the types of MS?

Relapsing-remitting MS (RRMS, 85%): discrete relapses with recovery periods; the most treatable form. Secondary progressive MS (SPMS): follows RRMS after years, with steady neurological worsening ± relapses. Primary progressive MS (PPMS, 15%): continuous worsening from onset without clear relapses; more common in men and older adults; harder to treat. Clinically isolated syndrome (CIS): a first MS-like episode — approximately 50% convert to MS within 10 years.

MS is multifactorial — genetic predisposition plus environmental triggers. Genetic: HLA-DRB1*15:01 is the strongest risk gene; >200 genetic variants contribute small risks. Environmental: low vitamin D (strong evidence for sun exposure protection); Epstein-Barr virus (EBV) — landmark 2022 study showed EBV exposure preceded virtually all MS cases; smoking (1.5x risk); obesity in adolescence; salt intake. MS is NOT directly inherited — risk in first-degree relatives is approximately 20-fold above background (2-3%).

MS diagnosis uses the McDonald Criteria (2017) — requiring evidence of demyelinating disease disseminated in space (multiple CNS regions) and time (multiple episodes or MRI activity). Key tools: MRI brain and spinal cord (white matter plaques, gadolinium-enhancing lesions); CSF analysis (oligoclonal bands — present in 95% of MS); visual evoked potentials; and exclusion of mimics. Early diagnosis is critical — treatment started early prevents significant disability.

What treatments are available?

Acute relapses: high-dose IV or oral methylprednisolone. Disease-modifying therapies (DMTs) by efficacy tier: moderate-efficacy (interferons beta, glatiramer acetate, dimethyl fumarate, teriflunomide); high-efficacy (natalizumab, ocrelizumab, ofatumumab, cladribine, alemtuzumab — 65-96% relapse rate reduction). For PPMS: ocrelizumab (first approved treatment). Symptomatic management: physiotherapy, fatigue management, bladder care, pain management. New oral BTK inhibitors are in Phase 3 trials.

MS itself is rarely directly fatal. However, it significantly reduces life expectancy by approximately 7-10 years — primarily from complications: infections (urinary tract infections, aspiration pneumonia in advanced disease), suicide (2-3 times higher risk than general population), and cardiovascular disease. Highly active disease in early MS predicts worse long-term outcomes — emphasising the importance of early high-efficacy treatment.

What is Epstein-Barr virus's role in MS?

A landmark 2022 study in Science (Bjornevik et al.) analysed 10 million US military personnel — finding that EBV infection PRECEDED virtually all MS cases, with a 32-fold increased MS risk after EBV infection. This provides the strongest causal evidence yet for a single environmental trigger of MS. It suggests EBV may initiate the autoimmune process via molecular mimicry (EBV proteins resembling myelin proteins triggering cross-reactive immunity). EBV-directed vaccines and monoclonal antibodies are now in MS clinical trials.

What is the access to MS treatment globally?

MS DMTs are among the most expensive chronic disease medications — $50,000-100,000/year in high-income countries. Generic interferons and glatiramer acetate are available at lower cost. In LMICs, most MS patients receive no DMT. MS prevalence is rising in previously low-prevalence regions (Africa, Asia, Latin America) where treatment is least accessible. WHO has called for MS inclusion in UHC essential packages.

Can people with MS lead normal lives?

With modern high-efficacy DMT and proper support, many people with MS lead full working and family lives — particularly those with relapsing forms diagnosed early. Disability varies enormously: approximately 50% will need walking aids after 15 years without effective treatment; with high-efficacy DMT started early, this proportion is substantially lower. Comprehensive multidisciplinary care — neurologist, physiotherapist, occupational therapist, psychologist, specialist nurse — optimises outcomes.

What is progressive MS and is it treatable?

Progressive MS (both primary and secondary) is the more disabling form — characterised by steady neurological worsening driven by neuroaxonal loss and CNS-resident inflammation (microglia). It responds less well to traditional DMTs than relapsing MS. Ocrelizumab (for PPMS), siponimod and ozanimod (for active SPMS) have modest effects on slowing progression. BTK inhibitors — targeting CNS-resident immune cells — are the most promising emerging approach for progressive MS.

How does GMJ News cover MS?

GMJ News covers MSIF Atlas data, DMT clinical trial results, EBV research advances, BTK inhibitor development and MS treatment access equity. MS is a significant neurological burden in Georgia — directly relevant to PHIG's neurological health priorities and the Georgian Medical Journal.

Home › Topics › Multiple Sclerosis

Multiple Sclerosis

GMJ News knowledge hub · last reviewed September 2026 · Georgian Medical Journal

Summary Statistics Glossary GMJ news FAQ Documents Organizations Research

Multiple sclerosis (MS) is the most common immune-mediated demyelinating disease of the central nervous system — affecting approximately 2.9 million people globally and the fastest-growing neurological condition after Parkinson's disease, driven by increasing incidence particularly in women and in previously low-prevalence regions (WHO / MS International Federation 2023). MS is caused by immune-mediated destruction of myelin sheaths in the brain and spinal cord, causing progressive disability through relapses and — in many patients — eventual secondary progression. The disease-modifying therapy (DMT) revolution — from interferons to high-efficacy monoclonal antibodies and emerging oral BTK inhibitors — has transformed MS from a uniformly progressive disease to one manageable for decades.

Key messages

2.9 million people

Multiple sclerosis affects 2.9 million people globally — and is the fastest-growing neurological condition after Parkinson's, with incidence rising particularly in women and in historically low-prevalence regions (MS International Federation 2023).

Immune-mediated demyelination

MS is caused by immune-mediated destruction of myelin sheaths in the brain and spinal cord, causing plaques that disrupt nerve signal transmission — leading to relapses and progressive disability affecting movement, vision, cognition and bladder function.

Three main types

Relapsing-remitting MS (RRMS — 85% of cases) causes discrete attacks followed by recovery; secondary progressive MS (SPMS) follows RRMS with steady worsening; primary progressive MS (PPMS — 15%) worsens from onset without relapses.

DMT revolution

Disease-modifying therapies (DMTs) have transformed MS from a uniformly progressive disease. High-efficacy agents (natalizumab, ocrelizumab, ofatumumab) reduce relapse rates by 65-96% and slow disability progression significantly.

Women affected 3:1

MS disproportionately affects women — the female:male ratio has risen from 2:1 to nearly 3:1 over 50 years, reflecting changes in environmental exposures, lifestyle factors and possibly hormonal influences on immune function.

Access gap

MS DMTs cost $50,000-100,000/year in high-income countries. Access in LMICs is extremely limited — most patients receive no disease-modifying treatment. The WHO Essential Medicines List includes only glatiramer acetate and interferon beta.

Key statistics

2.9M

people with MS globally (2023)

MS International Federation

3:1

female to male ratio

MS International Federation

20-40yr

typical age of onset

WHO

85%

have relapsing-remitting MS

WHO/MSIF

96%

relapse rate reduction with top DMTs

Cochrane/ECTRIMS

+30%

increase in MS prevalence over 20 years

MSIF 2023

MS prevalence per 100,000 population by region — MS International Federation Atlas 2023

Source: MS International Federation Atlas 2023. Highest prevalence in Northern Europe and North America.

Glossary of key terms

Myelin
Neuroscience/WHOThe fatty insulating sheath surrounding nerve fibres, enabling rapid electrical signal transmission. In MS, the immune system attacks and destroys myelin (demyelination), slowing or blocking nerve signals and causing MS symptoms.

Relapse (exacerbation)
WHO/EANAn episode of new or worsening MS symptoms lasting more than 24 hours, in the absence of fever or infection — caused by acute inflammation in the CNS. Treated with high-dose corticosteroids to reduce duration.

Ocrelizumab (Ocrevus)
FDA/EMAA humanised anti-CD20 monoclonal antibody — the first DMT approved for both RRMS and PPMS. Given IV every 6 months; reduces relapse rates by 96% (vs placebo) in RRMS and slows disability in PPMS.

MRI in MS
WHO/ECTRIMSMagnetic resonance imaging is essential for MS diagnosis — showing white matter plaques (T2 hyperintensities) and active inflammation (gadolinium-enhancing lesions). McDonald Criteria incorporate MRI findings for diagnosis.

BTK inhibitors
ResearchBruton tyrosine kinase (BTK) inhibitors — fenebrutinib, tolebrutinib, evobrutinib (in trials) — represent a potential next-generation oral MS therapy targeting both peripheral immune cells and CNS-resident microglia, potentially addressing progressive MS.

McDonald Criteria
ECTRIMS/AANThe international diagnostic criteria for MS (2017 revision) — requiring demonstration of dissemination in space (different CNS locations) and dissemination in time (attacks at different time points) through clinical, MRI and CSF evidence.