Resource Library

Multiple sclerosis is an autoimmune disease that affects the brain and spinal cord (central nervous system).

MS; Demyelinating disease

Multiple sclerosis (MS) affects woman more than men. The disorder most commonly begins between ages 20 and 40, but can be seen at any age.

MS is caused by damage to the myelin sheath, the protective covering that surrounds nerve cells. When this nerve covering is damaged, nerve impulses are slowed down or stopped.

MS is a progressive disease, meaning the nerve damage (neurodegeneration) gets worse over time. How quickly MS gets worse varies from person to person.

The nerve damage is caused by inflammation. Inflammation occurs when the body's own immune cells attack the nervous system. Repeated episodes of inflammation can occur along any area of the brain and spinal cord.

Researchers are not sure what triggers the inflammation. The most common theories point to a virus or genetic defect, or a combination of both.

MS is more likely to occur in northern Europe, the northern United States, southern Australia, and New Zealand than in other areas. Geographic studies indicate there may be an environmental factor involved.

People with a family history of MS and those who live in a geographical area with a higher incidence rate for MS have a higher risk of the disease.

Symptoms vary, because the location and severity of each attack can be different. Episodes can last for days, weeks, or months. These episodes alternate with 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.

Because nerves in any part of the brain or spinal cord may be damaged, patients with multiple sclerosis can have symptoms in many parts of the body.

Muscle symptoms:

• Loss of balance
• Muscle spasms
• Numbness or abnormal sensation in any area
• Problems moving arms or legs
• Problems walking
• Problems with coordination and making small movements
• Tremor in one or more arms or legs
• Weakness in one or more arms or legs

Bowel and bladder symptoms:

• Constipation and stool leakage
• Difficulty beginning to urinate
• Frequent need to urinate
• Strong urge to urinate
• Urine leakage (incontinence)

Eye symptoms:

• Double vision
• Eye discomfort
• Uncontrollable rapid eye movements
• Vision loss (usually affects one eye at a time)

Numbness, tingling, or pain

• Facial pain
• Painful muscle spasms
• Tingling, crawling, or burning feeling in the arms and legs

Other brain and nerve symptoms:

• Decreased attention span, poor judgment, and memory loss
• Diffulty reasoning and solving problems
• Depression or feelings of sadness
• Dizziness and balance problems
• Hearing loss

Sexual symptoms:

• Problems with erections
• Problems with vaginal lubrication

Speech and swallowing symptoms:

• Slurred or difficult-to-understand speech
• Trouble chewing and swallowing

Fatigue is a common and bothersome symptoms as MS progresses. It is often worse in the late afternoon.

Symptoms of MS may mimic those of many other nervous system disorders. The disease is diagnosed by ruling out other conditions.

People who have a form of MS called relapsing-remitting may have a history of at least two attacks, separated by a period of reduced or no symptoms.

The health care provider may suspect MS if there are decreases in the function of two different parts of the central nervous system (such as abnormal reflexes) at two different times.

A neurological exam may show reduced nerve function in one area of the body, or spread over many parts of the body. This may include:

• Abnormal nerve reflexes
• Decreased ability to move a part of the body
• Decreased or abnormal sensation
• Other loss of nervous system functions

An eye examination may show:

• Abnormal pupil responses
• Changes in the visual fields or eye movements
• Decreased visual acuity
• Problems with the inside parts of the eye
• Rapid eye movements triggered when the eye moves

Tests to diagnose multiple sclerosis include:

• Lumbar puncture (spinal tap) for cerebrospinal fluid tests, including CSF oligoclonal banding
• MRI scan of the brain and MRI scan of the spine are important to help diagnose and follow MS
• Nerve function study (evoked potential test)

For additional information, see multiple sclerosis resources.

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 continue to walk and function at work with minimal disability for 20 or more years.

The following typically have the best outlook:

• Females
• People who were young (less than 30 years) 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 you have attacks
• How severe they 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. Over time, many require a wheelchair to get around and have a more difficult tijme transferring out of the wheelchair.

Those with a support system are often able to remain in their home.

• Depression
• Difficulty swallowing
• Difficulty thinking
• Less and less ability to care for self
• Need for indwelling catheter
• Osteoporosis or thinning of the bones
• Pressure sores
• Side effects of medications used to treat the disorder
• Urinary tract infections

Call your health care provider if:

• You develop any symptoms of MS
• Symptoms get worse, even with treatment
• The condition deteriorates to the point where home care is no longer possible

Calabresi P. Multiple sclerosis and demyelinating conditions of the central nervous system. In: Goldman L, Ausiello D, eds. Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 436.

Goodin DS, Cohen BA, O'Connor P, et al. Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Assessment: the use of natalizumab (Tysabri) for the treatment of multiple sclerosis (an evidence-based review): report of the Therapeutics and Technology Assessment Subcommittee of the American Academy of Neurology. Neurology. 2008:71(10):766-73.

Farinotti M, Simi S, Di Pietrantonj C, McDowell N, Brait L, Lupo D, Filippini G. Dietary interventions for multiple sclerosis. Cochrane Database Syst Rev. 2007 Jan 24;(1):CD004192.

Kappos L, Freedman MS, Polman CH, et al. Effect of early versus delayed interferon beta-1b treatment on disability after a first clinical event suggestive of multiple sclerosis: a 3-year follow-up analysis of the BENEFIT study. Lancet. 2007:370(9585):389-97.

Miller DH, Leary SM. Primary-progressive multiple sclerosis. Lancet Neurol. 2007;6:903-912.