Multiple Sclerosis (MS)

Overview

Multiple sclerosis (MS) is a chronic disorder of the central nervous system. MS is an autoimmune disease. This means the immune system, which normally fights off germs, viruses, bacteria, and other threats, mistakenly attacks the body instead. In MS, the immune system attacks the myelin (the fatty protective coating around nerve fibers), as well as the nerve cells themselves.

Signs and Symptoms

MS affects people differently. A small number of people with MS will have mild symptoms with little disability, while others experience worsening symptoms that lead to increased disability over time. Most people with MS have short periods of symptoms that resolve fully or partially, followed by stretches with more minor or sometimes no noticeable symptoms. Symptoms usually begin between ages 20 and 40 but can begin in childhood or later in adulthood.

MS is one disease, but it can look different person to person. Doctors describe four main disease patterns of MS:

1. Relapsing-remitting MS: Symptoms come in recurrent attacks with total or partial recovery. Periods between attacks are called remission.
2. Secondary-progressive MS: Relapsing-remitting MS can gradually evolve into secondary-progressive MS. Attacks become less common, but people gradually develop steady symptoms that worsen over time.
3. Primary-progressive MS: This less common course has progressively worsening symptoms from the beginning, with no noticeable acute attacks.
4. Radiologically isolated syndrome: A person has abnormal MRI results that look like MS but has no MS symptoms. MS symptoms may develop in the future.

Early MS symptoms can include:

• Vision problems, such as double vision or vision loss (often with pain when the eyes move)
• Muscle weakness, often in the arms and legs, and muscle stiffness with painful muscle spasms
• Tingling, numbness, or pain in the arms, legs, trunk, or face
• Clumsiness, especially difficulty staying balanced when walking
• Bladder control problems, including more frequent urination, loss of bladder control, and constipation
• Dizziness

Muscle weakness, stiffness, and spasms may be severe enough to affect walking or standing. In some cases, MS leads to partial or complete paralysis.

MS may also cause:

• Mental or physical fatigue
• Mood changes such as depression or difficulty with emotional expression or control
• Cognitive changes, including problems concentrating, multitasking, thinking, or learning, or difficulties with memory or judgment
• Sexual dysfunction
• Tremor

Many people with MS find that their preexisting symptoms worsen when they have a fever, are exposed to heat, or experience common infections. This is called “pseudo-relapse.”

Causes and Risk Factors

In MS, the immune system attacks the myelin (the fatty protective coating around nerve fibers), as well as the nerve cells themselves. Risk factors for MS include the following:

Sex and Race

Women are more likely to develop MS than men, though men often have a more aggressive clinical course. People of all races and ethnicities can develop MS.

Family History and Genetics

Having a parent or sibling with MS increases the chances of developing MS. Research suggests that hundreds of genes and gene variants may work together to raise a person’s risk of MS. Some of the known genes are similar to those identified in people with other autoimmune diseases, such as inflammatory bowel disease, celiac disease, type 1 diabetes, rheumatoid arthritis, or lupus.

Viral Exposure

Several viruses have been found in people with MS. The virus most consistently linked to the development of MS is the Epstein-Barr virus (EBV), which causes infectious mononucleosis. Most people get EBV at some point in their lives. The small number of people who have never had EBV are actually less likely to get MS. People who acquired EBV during childhood are at lower risk of developing MS than people infected in adolescence or adulthood. However, the vast majority of people who acquire EBV will not develop MS.

Vitamin D and Sun Exposure

Research indicates that people who spend more time in the sun and have higher vitamin D levels are less likely to develop MS. They also tend to have a less severe disease course and fewer relapses. People from regions near the equator, where there is a great deal of bright sunlight, generally have a much lower risk of MS than people from temperate areas such as the United States and Canada.

Smoking

Studies have found that people who smoke are more likely to develop MS and have a more aggressive disease course. They also tend to have more severe damage to their brain and more brain shrinkage than nonsmokers.

Diagnosis

There is no single test to diagnose MS. Doctors use different tests to rule out or confirm the diagnosis. In addition to a complete medical history, physical examination, and detailed neurological examination, a doctor may recommend the following:

• Magnetic resonance imaging (MRI) scans of the brain, spinal cord, and sometimes optic nerves is used to look for the characteristic damage caused by MS. This is the most important test in the work-up of possible MS, and in most cases, doctors can diagnose MS by considering a person’s symptoms and identifying characteristic MS findings on an MRI. Doctors may inject a special dye into a vein to help spot new areas of damage. An MRI can also find damage in other parts of the nervous system that has no symptoms. Finding the damage can help doctors diagnose MS even after one attack.
• Lumbar puncture (sometimes called a spinal tap) is used to obtain a sample of cerebrospinal fluid (CSF) and examine it for proteins and inflammatory cells associated with the disease. This can also test for diseases that may look like MS.
• Evoked potential tests uses small sensors (electrodes) to measure how the brain responds to sights, touch, and sounds.
• Optical coherence tomography (OCT) detects optic nerve damage.

Treatment and Management

There is no cure for MS, but treatments can reduce the number and severity of relapses and slow the accumulation of MS-related disability. Most people with MS have a normal life expectancy.

Short-Term Treatment with Corticosteroids

Doctors can prescribe a short course of corticosteroids, usually injected into a vein. Corticosteroids quickly and effectively suppress the immune system and reduce inflammation. Clinical trials have shown that these medicines make recovery from MS attacks faster, but they do not alter the long-term outcome of the disease.

Long-Term Treatments

Current therapies approved by the U.S. Food and Drug Administration (FDA) for MS are designed to regulate or suppress the inflammatory reactions of the disease. They are most effective for relapsing-remitting MS or secondary-progressive MS with attacks.

Highly effective antibody treatments include:

• Ocrelizumab treats adults with relapsing-remitting or active secondary-progressive MS and is currently the only FDA-approved disease-modifying therapy for primary-progressive MS. Side effects include infusion-related reactions and increased risk of infections. Ocrelizumab may slightly increase the risk of cancer and reduce the effectiveness of some vaccines.
• Ublituximab is similar to ocrelizumab but is not approved for primary-progressive MS.
• Ofatumumab is similar to ocrelizumab and ublituximab but is injected under the skin rather than into the veins.
• Natalizumab works by preventing some immune system cells in the blood from entering the central nervous system. It is very effective but is associated with an increased risk of a serious and potentially fatal brain infection called progressive multifocal leukoencephalopathy (PML). Regular blood tests for antibodies to the virus that causes PML can help address this risk.
• Alemtuzumab targets proteins on the surface of immune cells. Because this drug increases the risk of autoimmune disorders, it is usually used in those who have not responded well enough to two or more MS therapies.

Oral treatments include:

• Fingolimod reduces the MS relapse rate in adults and children. It is the first FDA-approved drug to treat MS in adolescents and children aged 10 and older. It may result in a slow heart rate and eye problems when first taken and can increase the risk of infections.
• Siponimod, Ponesimod, and ozanimod have a similar mechanism of action to fingolimod.
• Dimethyl fumarate treats relapsing forms of MS. Side effects include flushing, diarrhea, nausea, and lowered white blood cell count.
• Diroximel fumarate and monomethyl fumarate are similar to dimethyl fumarate.
• Teriflunomide reduces the rate of growth in the number of activated immune cells. Side effects can include nausea, diarrhea, liver damage, and hair loss.
• Cladribine targets certain types of white blood cells that drive immune attacks in MS.

Older injectable medicines include:

• Beta interferon drugs, which were once the most commonly used treatments for MS but are less used now. Potential side effects include flu-like symptoms, depression, or elevation of liver enzymes.
• Glatiramer acetate, which can reduce the frequency of attacks in relapsing-remitting MS.

Living With MS

Many symptoms of MS can be treated or managed. The following approaches may help:

Eyes and Vision

Vision therapy exercises, special eyeglasses, and resting the eyes may be helpful.

Muscles and Mobility

Physical inactivity can contribute to worsening stiffness, weakness, pain, fatigue, and other symptoms, so it is very important that people with MS stay physically active. Stretching and exercising muscles through water therapy, yoga, or physical therapy can help manage muscle tightness and spasms. Assistive devices are sometimes helpful for people with tremor. Deep brain stimulation and medicines may also help.

People with severe movement coordination problems generally benefit from the use of a cane, walker, or other assistive device. In addition, occupational therapy can help people learn how to walk using an assistive device or in a way that saves physical energy. The FDA has also approved the drug dalfampridine to improve walking speed in people with MS.

Fatigue

Daily physical activity programs of mild to moderate intensity may reduce fatigue, although people should avoid excessive physical activity and minimize exposure to high temperatures. Physical therapy and occupational therapy can sometimes help manage fatigue. Stress management programs or relaxation training may help some people.

Bladder Control and Constipation

Medical treatments are available for bladder-related problems. Constipation can be treated with a high-fiber diet, laxatives, and stool softeners.

Sexual Dysfunction

Some problems can be corrected with medicines, and counseling may be helpful.

Depression

Depression is often treated with talk therapy and a type of antidepressant drug called SSRIs, which are less likely than other antidepressants to cause fatigue.

Thinking and Memory

If depression causes cognitive impairment, treating the depression may help.

Find Clinical Trials

Clinical trials uncover better ways to prevent, diagnose, treat, and understand diseases and conditions. To ensure results apply to everyone, volunteers of all ages, sexes, and backgrounds, including both healthy individuals and those with specific medical conditions, are needed. Find clinical trials on multiple sclerosis.

Community Support

The following organizations provide information and support for people with MS and their families:

• Accelerated Cure Project for Multiple Sclerosis
• Autoimmune Association
• Multiple Sclerosis Association of America (MSAA)
• Multiple Sclerosis Foundation (MS Focus)
• Myelin Repair Foundation (MRF)
• National Ataxia Foundation (NAF)
• National Multiple Sclerosis Society
• National Organization for Rare Disorders (NORD)
• National Rehabilitation Information Center (NARIC)
• Paralyzed Veterans of America

Note: This resource list is for informational purposes only. It is not comprehensive, and an organization’s inclusion does not constitute an endorsement by NIH. 

Research Information

The National Institutes of Health (NIH) is the largest public funder of biomedical research in the world. NIH invests most of its budget in medical research seeking to enhance life and to reduce illness and disability. NIH-funded research has led to breakthroughs and new treatments helping people live longer, healthier lives, and building the research foundation that drives discovery.

NIH is the leading federal funder of research on the brain and nervous system, including MS. Although researchers have not yet identified the exact causes of MS, there has been excellent progress, especially in the development of new treatments to slow the disease’s course.

NIH-supported research covers a wide range of topics, including:

• Biomarkers to accurately diagnose MS and monitor disease progression and treatment response, including blood and imaging tests
• Genetic and environmental risk factors for MS
• The role of diet in MS, as well as the influence of the bacteria and other microbes living in the digestive system, known as the gut microbiome
• Why MS affects men and women differently
• How a person’s environment, income, and other social factors, affect MS outcomes
• The role of the immune system in MS, including its function in the central nervous system
• How MS damages nerve fibers and their protective coatings, and how to stop that damage

Find NIH-funded research projects using NIH RePORTER, a searchable database of current and past research projects supported by NIH and other federal agencies.