Understanding Multiple Sclerosis (MS)
Last updated March 14, 2022, by Patricia Silva, PhD
Fact-checked by Ines Martins, PhD
What is MS?
Multiple sclerosis (MS) is a neurodegenerative disorder caused by the immune system mistakenly attacking the myelin sheath, a protective coating around nerve fibers. This results in inflammation, which further damages the myelin sheath, as well as the nerve cells themselves and the cells that produce myelin.
What are the types of MS?
There are four types of MS, broadly classified based on disease progression.
Clinically isolated syndrome
Clinically isolated syndromeĀ represents a single event, the first episode of neurological symptoms that typically precedes relapsing forms of MS. On its own, a single event is not enough to define MS, unless patients have evidence of several lesions in their brains. Thatās what the āmultipleā refers to in āmultiple sclerosis.ā
Relapsing-remitting multiple sclerosis
Relapsing-remitting multiple sclerosisĀ (RRMS) is the most common type of MS. Patients experience attacks of increasing neurological symptoms, called exacerbations or relapses, followed by periods of partial or complete recovery, called remissions. At various times, patients may have active, not active, or worsening neurological symptoms.
Secondary progressive multiple sclerosis
Secondary progressive multiple sclerosis (SPMS) is the secondary stage of MS that follows RRMS. Patients may have relapsing-remitting episodes initially, but then they experience a steady worsening of neurological symptoms over time that may be accompanied by occasional relapses.
Primary progressive multiple sclerosis
Primary progressive multiple sclerosisĀ (PPMS) affects about 15% of MS patients. Instead of periods of relapses followed by remission, people with PPMS experience a steady decline in neurological function without relapses from the onset of symptoms.
Quick Facts: Multiple sclerosis (MS) is an autoimmune disease in which the bodyās immune system attacks and destroys myelin, a fatty substance that covers and protects nerve fibers. This results in a variety of symptoms, including mobility issues, fatigue, cognitive problems, and chronic pain.
The exact cause of MS is unknown, but potential risk factors include:Ā
- Genetics
- Geography
- Vitamin D
- Smoking
- Biological sex
- Obesity
- Infections
MS is diagnosed through a variety of tests including MRIs, blood and cerebrospinal fluid tests, and evoked potential tests. No cure exists for MS yet, but there are treatments that can help manage the disease and its symptoms. These include:
- Disease-modifying therapies
- Relapse management therapies
- Symptomatic treatments