About Multiple Sclerosis

Multiple sclerosis (MS) is a chronic disease in which the immune system attacks myelin (the fatty coating around neurons) in the brain and spinal cord, damaging the neurons and impairing signal transmission. 

Multiple Sclerosis Facts and Figures

In the U.S., there are approximately 913,000 people living with MS 1

Rates of MS are higher further from the equator 2

RRMS is the most common type of MS. Approximately 85% of people receive an initial diagnosis of RRMS 2

Untreated, about 50% of people with RRMS will transition to SPMS within a decade of initial diagnosis 2

PPMS is diagnosed in about 15% of people with MS 2

The cost of living with MS depends on the degree of disability of the patient. One way to measure disability is through the Expanded Disability Status Scale (EDSS). Using the EDSS score, and the results from a 2016 study published on MS costs, Optum Rx estimated that: 3,4

the cost for treating patients with mild to moderate disability (3.0 to 3.5 on the EDSS) is $30,000 per year

the cost for treating patients with moderate disability (3.5 to 6.5 on the EDSS) is $50,000 per year; and

the cost for treating patients with severe disability (6.5 to 10 on the EDSS) is over $100,000 per year

Current Treatments and Unmet Needs

There is no cure for MS. Approved therapy for MS can be divided into several categories.

1. Treatment of acute attacks

2. Treatment with disease modifying agents that slow

progression of the disease

3. Treatment of MS symptoms

What are the types of Multiple Sclerosis?

Clinically isolated syndrome involves one episode of symptoms lasting at least 24 hours. These symptoms are due to demyelination in the central nervous system (CNS). Typical symptoms of CIS are optic neuritis (experienced by poor vision, blind spots, double vision), transverse myelitis (experienced by muscle weakness, numbness, tingling, bladder issues) and Lhermitte’s sign (experienced by an electric shock feeling in the neck). There are two types of CIS episodes: monofocal and multifocal. A monofocal episode means one lesion causes one symptom. A multifocal episode means the patient has more than one lesion and more than one symptom. 

Note: although these episodes are characteristic of MS, they aren’t enough to prompt a diagnosis of MS.

If lesions similar to those that occur with MS are present, a patient is more likely to receive a diagnosis of relapsing-remitting MS. If these lesions aren’t present, a patient is less likely to develop MS.

Relapsing-remitting MS involves clear relapses of disease activity followed by remissions. During remission periods, symptoms are mild or absent and there’s no disease progression. RRMS is the most common form of MS at onset and accounts for approximately 85% of all cases.

In people with PPMS, neurological function becomes progressively worse from the onset of symptoms. Over time it becomes increasingly difficult for signals from the brain to get through to the rest of the body. The rate of progression can vary. It’s possible for people to maintain a steady state without new or worsening symptoms for extended periods. There are no clear relapses and remissions like those of RRMS. Common early symptoms of PPMS include weakness in the legs and problems with walking.

Secondary progressive MS occurs when RRMS transitions into the progressive form. A patient may still have noticeable relapses in addition to disability or gradual worsening of function.


  1. Wallin, M.T., Culpepper, W.J., Campbell, J.D., Nelson, L.M., Langer-Gould, A., Marrie, R.A., Cutter, G.R., Kaye, W.E., Wagner, L., Tremlett, H., et al. (2019). The prevalence of MS in the United States. Neurology 92, e1029–e1040.Source: National MS Society and NCBI.
  2. Multiple Sclerosis Insight Report. https://www.optum.com/content/dam/optum/resources/whitePapers/M53018_G_MS_Insight_Report_ORx_FINAL.pdf. Accessed March 17, 2020.
  3. Owens, G.M. (2016). Economic burden of multiple sclerosis and the role of managed care organizations in multiple sclerosis management. Am J Manag Care 22, s151-158. 
  4. Hauser, S., and Josephson, S.A. (2016). Harrison’s Neurology in Clinical Medicine, 4th Edition (New York: McGraw-Hill Education / Medical).