Multiple Sclerosis

Multiple sclerosis (MS) is a disease of the brain and spinal cord. The condition can cause problems with muscle control and strength, vision, balance and sensation (such as numbness or tingling in the feet or hands).

Symptoms of MS are caused by inflammation in the brain and spinal cord and destruction of the protein coating (myelin) that surrounds and protects nerve fibers. This process is called demyelination. The damage from demyelination disrupts the normal flow of messages (nerve impulses) through the brain, spinal cord and nerves that control how a person moves and feels. In many cases, the nerve fibers (axons) are also destroyed.

MS affects individuals in different ways. For people who have mild symptoms now and then, the disease may not have much impact on their day-to-day lives. People with more severe MS have ongoing symptoms and may become disabled within a few years. Most people with MS are somewhere between these two extremes. For them, MS involves a series of attacks that cause symptoms of the disease. These attacks are called relapses, flares or exacerbations. They may last for days or weeks and then go away partially or completely. Relapses may be mild or severe and tend to recur over a period of years. They may become worse and more frequent over time, with the person's symptoms becoming more severe and disabling. For most people with MS, the disease follows a relapsing-remitting (come-and-go) course, at least at first. Some people with relapsing-remitting MS may later develop secondary progressive MS (ongoing damage to the nerves in the brain and spinal cord).

In the United States, multiple sclerosis affects 250,000 to 350,000 people, two-thirds of which are women. The disease varies with geographic location, family characteristics and age. Dealing with the physical, practical and emotional demands of MS is not easy, either for those affected by the disease or for their families and caregivers. With treatment, however, many people with MS can and do find ways to cope with their disease.

People who have MS do not all have the same symptoms. Symptoms vary according to the parts of the brain or spinal cord damaged by the disease. Symptoms may come and go or become more or less severe from day-to-day and hour-to-hour. Symptoms may become more severe with changes in body temperature or after a viral infection. The most common early symptoms of MS include:

Muscle (motor) symptoms, such as weakness, leg dragging, stiffness, a tendency to drop things, a feeling of heaviness, clumsiness or a lack of coordination (ataxia)
Visual symptoms, such as blurred, foggy or hazy vision, eyeball pain (especially with movement), blindness or double vision. At some point in the course of the disease, about 40% of people have an attack of optic neuritis, which causes sudden vision loss and eye pain, usually in only one eye.

Less common early symptoms include:

Sensory symptoms, such as tingling, pins-and-needles sensation, numbness, a band-like tightness around the trunk or limbs or electrical sensations moving down the back and limbs
Balance symptoms, such as lightheadedness or dizziness, a spinning feeling (vertigo), nausea or vomiting
Bladder symptoms, such as an inability to hold urine (urinary incontinence), inability to completely empty the bladder, loss of bladder sensation (the inability to sense the bladder becoming full until there is a sudden, urgent need to urinate) or a loss of male sexual function. These problems are not common in the early stages of the disease.

As MS progresses, symptoms may become more severe, including:

Stiff, mechanical movements or uncontrollable shaking
Pain and other sensory symptoms
Inability to control urination or an inability to urinate
Constipation and other bowel disorders
Impotence (erectile dysfunction)

Thinking (cognitive) and emotional problems are common in people who have had MS for some time. Since thinking and emotional problems may be treatable or may be caused by conditions other than MS, patients should always mention any new symptoms to the doctor.

Thinking problems may include memory loss, difficulty in concentration or speech problems. Emotional symptoms may include depression or mood disorders. A rare symptom is excessive cheerfulness that seems inappropriate.

Causes

The cause of multiple sclerosis is unknown. Because the risk of MS is significantly higher when a parent has the disease, genetic factors may play a role.

The unusual relationship between a person's geographic location during childhood and the risk of MS later in life suggests that there may be environmental factors at work in the disease. Some researchers think that these may be viral illnesses or other infectious diseases. However, there is no clear proof that any specific infection causes MS.

Furthermore, a childhood viral illness or other environmental factor is by itself not enough to explain why some people later develop MS. More and more research suggests that a problem with the body's natural defense system (immune system) occurring later in life may trigger the onset of MS in people who were exposed to certain factors during childhood. The trigger may be an autoimmune reaction in which the immune system attacks the protein coating (myelin) that protects nerve fibers.

Diagnosis

Multiple sclerosis (MS) is diagnosed when one or both of the following are present without another explanation for the symptoms:

The person has at least two neurologic episodes of signs and symptoms that could be caused by MS (weakness or clumsiness, vision problems, tingling or numbness or balance problems). Each episode must last at least 24 hours, and the episodes must occur at least one month apart.
There is at least one symptom that indicates an injury to one part of the central nervous system, and laboratory testing shows abnormal findings in at least one other area of the central nervous system.

Confirming a diagnosis of MS may take several years from the time the first symptoms appear. A medical history and neurologic examination, which can identify possible nervous system problems, are usually enough to give strong evidence of MS. Other tests may help confirm the diagnosis, including:

Magnetic resonance imaging (MRI) scan of the brain and spinal cord. More than 90% of people who have MS have an abnormal MRI. For people already diagnosed with multiple sclerosis, MRI scans may also be used to follow the progression of the disease.
Lumbar puncture (sometimes called a spinal tap) and cerebrospinal fluid analysis. Most people with MS have abnormal results on this test, such as elevated levels of a protein called immunoglobulin (Ig), the presence of a certain type of protein (oligoclonal banding of Ig) or a mild increase in white blood cells in the spinal fluid.
Evoked potential testing. This can often reveal problems in the brain and spinal cord (central nervous system) that a neurologic exam and other tests may not find.
Urinary tract tests may be needed to help diagnose an MS sufferer who has problems with bladder control.
Neuropsychologic tests may be needed to identify thinking or emotional problems. Typically, these tests are in a question-and-answer format. Doctors recognize that problems may be present that the patient has not noticed.

It is important that people who have MS be reexamined when new problems arise. New symptoms may be caused by other, treatable conditions, or they may signal a change in the person's disease that could affect treatment decisions.

Treatment

Multiple sclerosis has no cure. However, there are new medications (such as interferon beta and glatiramer acetate) that can reduce the number and seriousness of attacks in people with relapsing-remitting (come-and-go) MS and may slow the progression of the disease in people with secondary progressive MS. There is also some evidence to suggest that interferon beta may reduce or delay future disability.

Treatment can make living with the disease easier. The level of treatment needed and wanted by a person who has MS often depends on how severe symptoms are and how much the disease affects daily living. Treatment may focus on making a relapse shorter or less severe, altering the course of the disease and relieving symptoms.

When a person has an attack of MS, corticosteroids are usually given to shorten the relapse and limit how severe it is. However, these do not prevent disability from MS and have not been shown to delay or prevent worsening of the disease.

Therapies to modify the course of the disease usually involve drugs that hold off or change the activity of the immune system. These therapies are based on evidence that MS is, at least in part, a result of an abnormal action of the immune system that makes it attack normal tissues (in this case, the myelin coating around nerve fibers). There are several types of disease-modifying medications for treating MS.

Although these medications do not cure MS, they may reduce the overall number, frequency and seriousness of relapses in some people who have the relapsing-remitting form of MS. Interferon beta (but not glatiramer acetate or mitoxantrone) may also reduce or delay disability. Interferon beta-1b (Betaseron) and mitoxantrone (Novantrone) have been shown to benefit some people with secondary progressive MS.

Symptoms, such as spasticity (stiff, tight muscles), pain, fatigue, tremor, depression and bladder problems, often can be relieved by medications. Physical therapy, occupational therapy and home treatment methods may also help a person manage symptoms and adjust to living and working situations.

Many other treatments have been tried by people with MS, including electric stimulation of the brain or spinal cord, manipulation of the blood and lymph systems, special diets and nutritional supplements. None of these treatments have been scientifically proven to be effective in the treatment of MS.