Multiple sclerosis (MS) is a chronic, potentially debilitating disease that affects your brain and spinal cord (central nervous system). The illness is probably an autoimmune disease, which means your immune system responds as if part of your body is a foreign substance.In MS, your body directs antibodies and white blood cells against proteins in the myelin sheath surrounding nerves in your brain and spinal cord. This causes inflammation and injury to the sheath and ultimately to your nerves. The result may be multiple areas of scarring (sclerosis). The damage slows or blocks muscle coordination, visual sensation and other nerve signals.The disease varies in severity, ranging from a mild illness to one that results in permanent disability. Treatments can modify the course of the disease and relieve symptoms.An estimated 400,000 Americans have MS. It generally first occurs in people between the ages of 20 and 50. The disease is twice as common in women as in men.

How is Multiple Sclerosis Diagnosed?

MS is not easy to diagnose. There is no single conclusive test for MS. Other conditions may need to be ruled out. A GP should always refer a patient to a neurologist to make or confirm the diagnosis. The neurologist will not usually diagnose MS until there have been at least two occurrences of symptoms involving different areas of the central nervous system, at least a month apart and each lasting for at least 24 hours. This means that there is always a delay between the appearance of the first symptom and a diagnosis of MS. A clinical diagnosis, made by a doctor after seeing you for various MS-type symptoms over a period of time, needs to be backed up by tests. It may be necessary to have several different tests to identify MS. The following are the most commonly The following are the most commonly used tests for MS.

Neurological examination
This tests for abnormalities in nerve pathways involved in movement or sensation. The neurologist looks for changes in eye movements, co-ordination of legs or hands, balance, sensation, speech or reflexes, as well as any signs of weakness.

Evoked potentials
Evoked potentials test the time it takes for the brain to receive and interpret messages. This is a non-invasive and painless test. Small electrodes are placed on the head to monitor brain waves responding to what you see or hear. In a healthy person, responses are virtually instantaneous. If myelin damage has occurred, messages may take longer to get through.

MRI scan
The MRI (Magnetic Resonance Imaging) scanner is used in most areas of the country to diagnose MS. Linked to a computer, it takes detailed pictures of the brain and spinal cord. It is very accurate and can pinpoint the exact location and size of plaques. Over 90 per cent of people with MS have plaques that show up on MRI scans, but some people's scans show no myelin damage.

Lumbar puncture
This test has been used to diagnose MS for many years. A needle is inserted into the lower back, under local anaesthetic, and a small sample of cerebrospinal fluid (which flows around the brain and spinal cord) is taken from the spinal cord. This fluid is tested for abnormalities in protein patterns.

Other tests
Conditions that mimic MS can be ruled out by using MRI or other tests. These include CAT (Computer Axial Tomography) scans, which give a crosssectional image of the brain; tests to reveal certain antibodies in the blood; and inner ear tests to check balance.

What Causes MS?

Many factors are involved in MS, but no single cause has been identified.

An environmental agent such as a virus or bacterial infection may be involved. Some scientists argue that a virus disturbs the immune system or indirectly sets off a process whereby the immune system attacks itself. No single virus has been identified as being responsible for MS, but some researchers think that a common childhood virus may act as a trigger. Environmental factors seem to be influential in the first 15 years of life. Many people with MS have had viral illnesses such as measles, chickenpox, flu, herpes or glandular fever as children or teenagers.

Genetic factors
Some people with MS seem to have particular genes which give them a 'genetic predisposition' to MS; in other words, they make it more likely that they will develop the condition. These genes are also common in the general population, however. There is no single gene linked to MS.

Family links
MS is not hereditary (ie passed directly from parent to child), but it can occur in more than one member of a family. However, in the UK the chance of a child having MS when a parent is affected is very small; it is estimated to be three in 100, which is much lower than that for developing cancer or heart problems. The risk of being affected by MS for the UK population in general is one in 800.

Climate and geography
Countries with temperate climates have a higher incidence of MS cases, and the condition is more common in areas in northern latitudes such as Scotland. No one knows why this is the case. Some studies suggest that people who migrate to areas with temperate climates after the age of about 15 retain the likelihood of taking on MS corresponding to their country of origin, rather than taking on the increased likelihood associated with temperate climates.

Are there different types of MS?

There are four main types of MS, and a great deal of variation within each.
MS shows up differently in each person. Some people are only mildly affected throughout their lives. A few people deteriorate rapidly from the beginning and may die early. Most people with MS experience something in between these two extremes.

Benign MS
This type starts with a small number of mild attacks followed by complete recovery. It does not worsen over time and there is no permanent disability. The first symptoms usually affect sensation or sight. People are only classified as having benign MS when they have little sign of disability 10 to 15 years after the first onset of symptoms. However, disability may occasionally develop after many years in which the disease has been inactive. Around 20 per cent of people with MS have the benign form.

Relapsing-remitting MS
For most people MS starts as the relapsing-remitting type. This means they have relapses (a flare-up of symptoms), followed by remissions (periods of recovery). Relapses (also known as attacks or exacerbations) tend to be unpredictable and their causes are unclear. They can last for hours, days, weeks or months, and vary from mild to severe. During a relapse new symptoms may occur, previous symptoms may return. At their worst, acute relapses may need hospital treatment. Remissions can last any length of time - even years. No one knows exactly what makes MS go into remission. Even during remission there may still be plaques visible on MRI scans. In the early stages of relapsingremitting MS, symptoms usually disappear during remissions. However, after several attacks there may be some residual damage to myelin, resulting in the person being slightly more affected than before the relapse. Around 25 per cent of people with MS have the relapsing-remitting form.

Secondary progressive MS
Many people who start out with relapsing-remitting MS later develop a form known as secondary progressive. This means that disability does not go away after a relapse and progressively worsens between attacks, or that the cycle of attack followed by remission is replaced by a steady progression of disability. Around 40 per cent of people with MS develop the secondary progressive form, usually about 15 to 20 years after the initial onset of MS.

Primary progressive MS
Some people with MS never have distinct relapses and remissions. From the start they experience steadily worsening symptoms and progressive disability. This may level off at any time or may continue to get worse. Around 15 per cent of people with MS have the primary progressive form of the disease, which is also known as chronic progressive.

Symptoms of MS?

MS varies from person to person. No one experiences every symptom.

MS can cause a wide variety of symptoms. Many people only experience a few symptoms and no one has all of them. People can have different symptoms at different times, and although some are very common, there is no typical set that applies to everyone. Symptoms vary in severity and duration. They can range from mild and short-lived to severe and longer-lasting. Some symptoms are obvious to other people. Others (such as pain or fatigue) are hidden or 'silent', and may be harder for people unfamiliar with MS to understand.

Certain triggers can seem to make symptoms worse. The most common triggers tend to be overdoing things, exercise which raises core body temperature, fever, heat and humidity. Symptoms may start with double or blurred vision, pain at the back of the eye or nerve pain in the face. Some people experience ringing in the ears or hearing problems, tingling ('pins and needles') or numbness in the legs, feet, arms or hands. Others experience giddiness and loss of balance, especially in the dark. Some people may find it hard to concentrate, become forgetful, or experience anxiety, depression or mood swings.

Other symptoms may include fatigue (especially in hot weather), pain, weakness or difficulty in walking. Some people experience problems with speech or bladder or bowel control. Sexual function or sensation can be affected, and a person with MS may need more stimulation to become or stay aroused. These problems can come and go, like any other MS symptom. Symptoms are not necessarily unique to MS, and can be associated with other conditions. Effective treatments are available for most MS symptoms, and in some cases can reduce relapses. They should be discussed with your doctors or an MS nurse.

Help and support
You may feel upset at being told that you have MS. It may be hard to believe that the good health you had before has been taken away from you. You may feel a sense of loss or bereavement, which may take some time to understand. You may experience shock or bewilderment and feel angry and want to deny the diagnosis, carrying on as though nothing has happened. All these reactions are normal, but some people will experience them more acutely than others. See our booklet Making the most of life with MS for more information on coping with these reactions. Talking through your emotions and questions with someone else can be helpful. The freephone MS Helpline, telephone counselling lines and local contacts are there to support you. Details are included on the back page.

If your attacks are mild or infrequent, your doctor may advise a wait-and-see approach, with counseling and observation. However, if your diagnosis is a relapsing form of the disease, the form that affects the great majority of people with MS, your doctor may recommend treatment with disease-modifying medications as soon as possible.These medications include: Beta interferons. Interferon beta-1b (Betaseron) and interferon beta-1a (Avonex, Rebif) are genetically engineered copies of proteins that occur naturally in your body. They help fight viral infection and regulate your immune system. If you use Betaseron, you inject yourself under your skin (subcutaneously) every other day. If you use Rebif, you inject yourself subcutaneously three times a week. Avonex is self-injected into your muscle (intramuscularly) once a week. These medications reduce flares of MS. It's uncertain which of their many actions lead to a reduction in disease activity and what their long-term benefits are. Beta interferons should never be used in combination with one another. Only one of these medications should be used at a time. The Food and Drug Administration (FDA) has approved beta interferons only for people with relapsing forms of MS who can still walk. Beta interferons don't reverse damage and haven't been proved to prevent permanent disability.

Some people develop antibodies to beta interferons, which may make them less effective. Other people can't tolerate the side effects, which may include symptoms similar to those of the flu (influenza).Mayo Clinic neurologists generally recommend beta interferons for people who have more than one attack of MS a year and for those who don't recover well from flare-ups. The treatment may also be used for people who have a significant buildup of new lesions as seen on an MRI scan, even when there may not be major new symptoms of disease activity.

Glatiramer (Copaxone). This medication is an alternative to beta interferons if you have relapsing remitting MS. Glatiramer shouldn't be used at the same time as beta interferons. Glatiramer is as effective as beta interferons in curbing MS attacks. Doctors believe that glatiramer works by blocking your immune system's attack on myelin. You must inject glatiramer subcutaneously once daily. Side effects may include flushing and shortness of breath after injection.

Medications to relieve symptoms in progressive MS may include:

Corticosteroids. Doctors most often prescribe oral or intravenous corticosteroids to reduce inflammation in nerve tissue and shorten the duration of flare-ups. Prolonged use of these medications, however, may cause side effects such as osteoporosis and high blood pressure (hypertension).

Muscle relaxants. Tizanidine (Zanaflex) and baclofen (Lioresal) are oral treatments for muscle spasticity. If you have MS, you may experience muscle stiffening or spasms, particularly in your legs, which can be painful and uncontrollable. Lioresal often increases weakness in the legs. Zanaflex appears to control muscle spasms without leaving your legs feeling weak but can be associated with drowsiness or a dry mouth.

Medications to reduce fatigue. These may include the antidepressant medication fluoxetine (Prozac), the antiviral drug amantadine (Symmetrel) or a medication for narcolepsy called modafinil (Provigil). All appear to work because of their stimulant properties.

Many medications are used for the muscle stiffness, depression, pain and bladder control problems often associated with MS. Drugs for arthritis and medications that suppress the immune system may slow MS in some cases.

In addition to medications, these treatments may relieve symptoms of MS:

Physical and occupational therapy. The goal is to preserve independence by having you do strengthening exercises and use devices to ease daily tasks.

Counseling. Individual or group therapy may help you and your family cope with MS and relieve emotional stress.

Plasma exchange. Researchers are evaluating plasma exchange as an experimental approach to treating MS. This procedure involves removing some of your blood and mechanically separating the blood cells from the fluid (plasma). Your blood cells then are mixed with a replacement solution, typically albumin, or a synthetic fluid with properties like plasma. The solution with your blood is then returned to your body. It's uncertain why plasma exchange works. Replacing your plasma may dilute the activity of the destructive factors in your immune system and help you to recover. This treatment is only for people with sudden, severe attacks of MS-related disability who don't respond to high doses of steroid treatment. The treatment is most helpful for people with a mild pre-existing disability before the attack. Plasma exchange has no proven benefit beyond three months from the onset of the neurologic symptoms.