Multiple sclerosis (MS) affects women more than men. The disorder is most commonly diagnosed between ages 20 and 40, but it can be seen at any age.
MS is caused by damage to the myelin sheath. This sheath is the protective covering that surrounds nerve cells. When this nerve covering is damaged, nerve signals slow down or stop.
The nerve damage is caused by inflammation. Inflammation occurs when the body's own immune cells attack the nervous system. This can occur along any area of the brain, optic nerve, and spinal cord.
It is unknown what exactly causes MS. The most common thought is that a virus or gene defect, or both, are to blame. Environmental factors may also play a role.
You are slightly more likely to develop this condition if you have a family history of MS or you live in a part of the world where MS is more common.
Symptoms vary because the location and severity of each attack can be different. Attacks can last for days, weeks, or months. Attacks are followed by periods of reduced or no symptoms (remissions). Fever, hot baths, sun exposure, and stress can trigger or worsen attacks.
It is common for the disease to return (relapse). However, the disease may continue to get worse without periods of remission.
Nerves in any part of the brain or spinal cord may be damaged. Because of this, MS symptoms can appear in many parts of the body.
There is no known cure for multiple sclerosis at this time. But, there are treatments that may slow the disease. The goal of treatment is to control symptoms and help you maintain a normal quality of life.
Medicines are often taken long-term. These include:
Medicines to slow the disease
Steroids to decrease the severity of attacks
Medicines to control symptoms such as muscle spasms, urinary problems, fatigue, or mood problems
Medicines are more effective for the relapsing-remitting form than for other forms of MS.
Social workers or other counseling services to help you cope with the disorder and get assistance
Vitamin D or other supplements (talk to your doctor first)
Complementary and alternative approaches, such as acupressure or cannabis, to help with muscle problems
Living with MS may be a challenge. You can ease the stress of illness by joining an MS support group. Sharing with others who have common experiences and problems can help you not feel alone.
The outcome varies, and is hard to predict. Although the disorder is chronic and incurable, life expectancy can be normal or almost normal. Most people with MS are active and function at work with little disability.
The following typically have the best outlook:
People who were young (less than 30 years old) when the disease started
People with infrequent attacks
People with a relapsing-remitting pattern
People who have limited disease on imaging studies
The amount of disability and discomfort depends on:
How often and severe the attacks are
The part of the central nervous system that is affected by each attack
Most people return to normal or near-normal function between attacks. Slowly, there is greater loss of function with less improvement between attacks.
The condition worsens to the point where home care is no longer possible
Houtchens MK, Lublin FD, Miller AE, Khoury SJ. Multiple sclerosis and other inflammatory demyelinating diseases of the central nervous system. In: Daroff RB, Fenichel GM, Jankovic J, Mazziotta JC, eds. Bradley's Neurology in Clinical Practice. 6th ed. Philadelphia, PA: Saunders Elsevier; 2012:chap 54.
Polman CH, Reingold SC, Banwell B, et al. Diagnostic criteria for multiple sclerosis: 2010 revisions to the McDonald criteria. Ann Neurol. 2011;69:292-302.
Rubin S. Management of multiple sclerosis: an overview. Dis Mon. 2013;59:253-260.
Joseph V. Campellone, MD, Department of Neurology, Cooper University Hospital, Camden, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Isla Ogilvie, PhD, and the A.D.A.M. Editorial team.