Multiple Sclerosis

Multiple sclerosis affects 2.5 million people worldwide, including 400,000 Americans.

Multiple sclerosis (MS) is a serious chronic and progressive illness affecting your body's nerves to the point of complete disability.

MS is an autoimmune disease, whereby the body's immune system mistakenly attacks normal tissues. With MS, the immune system attacks the two components of the nervous system: the brain and spinal cord.

The central nervous system is made up of nerves that act as the body's messenger system. Each nerve is covered by a fatty substance called myelin.

Myelin is the white matter coating our nerves, enabling them to conduct impulses between the brain and other parts of the body. It consists of a layer of proteins packed between two layers of lipids.

Myelin insulates the nerves and helps in the transmission of nerve impulses, or messages, between the brain and other parts of the body. These messages control muscle movements, such as walking and talking.

MS gets its name from the buildup of scar tissue (sclerosis) in the brain and/or spinal cord. The scar tissue or plaques form when the protective and insulating myelin covering the nerves is destroyed, a process called demyelination. Without the myelin, electrical signals transmitted throughout the brain and spinal cord are disrupted or halted. The brain then becomes unable to send and to receive messages. It is this breakdown of communication that causes the symptoms of MS.

Although the nerves can regain myelin, this process is not fast enough to outpace the deterioration that occurs in MS. The types of symptoms, severity of symptoms, and the course of MS vary widely, partly due to the location of the scar tissue and the extent of demyelination.

Multiple sclerosis, with the exception of trauma, is the most frequent cause of neurological disability beginning in early to middle adulthood. MS is twice as common in females as in males and its occurrence is unusual before adolescence. A person has an increased risk of developing the disease from the teen years to age 35 with the risk gradually declining thereafter.

What Causes MS?

No one is sure what causes the body's immune system to go awry. Some scientists believe that it is a combination of genetics and something in the environment to which the person was exposed to early in life.

Epidemiological data show several interesting trends: Different populations and ethnic groups have a markedly different prevalence of MS. The disease is especially common in Scotland, Scandinavia, and throughout northern Europe. In the U.S. the prevalence of MS is higher in whites than in other racial groups. African blacks and Japanese people rarely (if ever) get MS, but African Americans and Japanese Americans do.

Studies show that MS is more common in certain parts of the world, but if you move from an area with higher risk to one of lower risk, you acquire the risk of your new home if the move occurs prior to adolescence. Such data suggest that exposure to some environmental agent encountered before puberty may predispose a person to MS.

Moreover, MS is a disease of temperate climates. In both hemispheres, its prevalence increases with distance from the equator.

Also there have been "epidemics" of MS -- for example, the group of people living off the coast of Denmark after WWII -- suggesting an environmental cause.

What Role Do Genetics Play in MS?

Researchers believe that MS may be inherited (passed on from parents to children). First, second and third degree relatives of people with MS are at increased risk of developing the disease. Siblings of an affected person have a 2%-5% risk of developing MS.

Researchers believe that there is more than one gene that makes a person more likely to get MS. Some scientists theorize that MS develops because a person is born with a genetic predisposition to react to some environmental agent, which, upon exposure, triggers an autoimmune response.

Sophisticated new techniques for identifying genes may help answer questions about the role of genetics in the development of MS.

What Viruses Are Linked to MS?

Some studies have suggested that many viruses such as measles, herpes, and the flu viruses may be associated with MS. To date, however, this belief has not been proven.

Are There Other Potential Factors That Cause MS?

There is growing evidence suggesting that hormones, including sex hormones, can affect and be affected by the immune system. For example, both estrogen and progesterone, two important female sex hormones, may suppress some immune activity. Testosterone, the primary male hormone, may also act as an immune response suppressor. During pregnancy, estrogen and progesterone levels are very high, which may help explain why pregnant women with MS usually have less disease activity. The higher levels of testosterone in men may partially account for the fact that women with MS outnumber men with MS by 2-3 to 1.

Diagnosing Multiple Sclerosis

There is no single test that is proof-positive for diagnosing multiple sclerosis. However, there are accepted criteria for making the diagnosis, but even this system is imperfect.

Since diagnosing MS can be very difficult, a neurologist who specializes in treating MS should evaluate your symptoms. As many as 10% of people diagnosed with multiple sclerosis actually have some other condition that mimics MS. Examples of other conditions that masquerade as MS include inflammation in the blood vessels, multiple strokes, vitamin deficiency, lupus, or brain infection. Sometimes stress-related disorders can lead to a misdiagnosis of MS.

How Is the Diagnosis Made?

An accurate diagnosis is based on your medical history and a neurological examination (examination of the function of the brain and spinal cord) using various tests. A lot depends on the skill of the doctor in asking the right questions to uncover information and to properly evaluate the signs and symptoms of a malfunctioning brain or spinal cord.

In addition to a thorough medical history and examination, a variety of specialized procedures are helpful -- although not always necessary -- to accurately diagnose MS. These include imaging techniques, such as MRI, spinal taps (examination of the cerebrospinal fluid that runs through the spinal column), evoked potentials (electrical tests to help determine if MS has affected a person's sensory nerve pathways), and laboratory analysis of blood samples.

What Are the Accepted Criteria for Diagnosis?

  • Onset usually occurs between 15 and 60 years of age
  • Symptoms and signs indicating disease of the brain or spinal cord
  • Evidence of two or more lesions upon examination by MRI scan
  • Objective evidence of disease of the brain or spinal cord on doctor's examination
  • A course following one of two patterns: two or more episodes lasting at least 24 hours and occurring at least one month apart, or a progressive course of signs and symptoms over at least six months
  • No other explanation for the symptoms

What Does an MRI Show?

MRI is the best test to view the changes caused by MS. The precise image produced by MRI gives the neurologist clear evidence of scar tissue in the deep parts of the brain or spinal cord that is characteristic of MS.

However, abnormal spots on the brain MRI can be caused by other conditions, so before making a diagnosis your doctor will consider all information including your symptoms and scan results. Similar lesions can be seen in elderly people or people with migraine headaches or high blood pressure.

Also, a normal MRI does not absolutely rule out a diagnosis of MS. About 5% of patients who are confirmed to have MS on the basis of other criteria, do not have lesions in the brain on MRI. These people may have lesions in the spinal cord or may have lesions that cannot be detected by MRI.

Will I Need a Spinal Tap?

Performing a spinal tap to examine the cerebrospinal fluid may be helpful in diagnosing MS in some people, but it is no longer considered necessary in all instances.

Experienced specialists will be able to determine if you need this test to confirm a suspected diagnosis of MS, particularly if your history and examination suggest the presence of the disease. Abnormalities that may appear in the cerebrospinal fluid can be very helpful in establishing a diagnosis but, like other tests, spinal taps are not foolproof in diagnosing MS.

What Other Tests Are Given?

Electrical tests of the nerve pathways, known as evoked potentials, are very helpful in confirming whether MS has affected the visual, auditory, or sensory pathways. These tests are done by placing wires on the scalp to test the brain's response to certain types of stimulation, such as watching a pattern on a video screen, hearing a series of clicks, or receiving electrical impulses in your arm or leg.

Your doctor may order a blood test to help rule out conditions that mimic (imitate) multiple sclerosis, but the presence of MS cannot be detected in the blood.

Accepting the Diagnosis

The diagnosis of multiple sclerosis can be a lengthy process. Upon hearing the diagnosis, you may feel a mixture of emotions, including denial, fear, relief, optimism, or hope. For some people, a diagnosis after months or years of symptoms is a relief, but for others it may be shocking. Even when a diagnosis of MS is made, the uncertainty is not over.

You may have some concerns about the unknown elements of the disease, its course and its impact. This is completely understandable. The course of MS is unpredictable; not knowing how the disease will affect you over the long term is probably the most difficult factor to deal with. Sharing your thoughts and emotions with others can help you cope with the diagnosis. Remember that MS affects everyone differently so what one person with MS experiences may not be what you will experience. To learn more about coping with a diagnosis of MS, visit Living With MS.

The MRI

To detect MS. MRI is considered the best test to help diagnose MS. However, 5% of people with MS do not have abnormalities detected on MRI, thus a "negative" scan does not completely rule out MS. In addition, some common changes of aging may look like MS on a MRI.

MRI's are also used to track the progress of disease. Although they aren't widely needed, sometimes someone with MS will get repeat scans to determine how fast the disease is progressing.

Spinal Tap

Your brain and spinal cord are bathed in spinal fluid. A spinal tap, also called a lumbar puncture, is a procedure that removes fluid from your spinal canal. Tests on this fluid may help your doctor diagnose disorders of the brain and spinal cord, including multiple sclerosis.

The fluid, called cerebrospinal fluid (CSF), contains glucose (sugar), proteins, and other substances that are also found in the blood. Analysis of the fluid includes looking at the number and types of white blood cells (infection fighting cells), the level of glucose, the types and levels of various proteins (especially immune system proteins called antibodies or immunoglobulins), and testing for bacteria, fungus, or other abnormal cells.

How Does a Spinal Tap Assist in the Diagnosis of MS?

A spinal tap that reveals a large number of immunoglobulins (antibodies) as well as oligoclonal bands (the pattern of immunoglobulins on a more specific test) or certain proteins that are the breakdown products of myelin is suggestive of MS. These findings indicate an abnormal autoimmune response within the brain and spinal cord, meaning that the body is attacking itself.

Over 90% of people with MS have oligoclonal bands in their CSF. While increased immunoglobulin in the CSF and oligoclonal bands are seen in many other brain and spinal cord conditions, their presence is often useful in helping to establish a diagnosis of MS.

However, a "negative" spinal tap does not rule out MS or other diseases. An abnormal autoimmune response in CSF is found in a number of other diseases, so the test is not specific for MS. Conversely, some 5%-10% of people with MS never show these CSF abnormalities. Therefore, analysis of the CSF by itself cannot confirm or rule out a diagnosis of MS. It must be part of the total clinical picture that takes into account other diagnostic procedures such as evoked potentials and magnetic resonance imaging.

After the spinal tap, your doctor may recommend that you lie down for several hours after the procedure to prevent a spinal headache. If you develop a headache, lie down as much as possible and drink plenty of caffeine-containing beverages. Drink 2 1/2 quarts of liquid the day of the test and the day after, even if you don't have a headache.

Avoid strenuous or vigorous exercise for a day or so following the spinal tap.

Treating MS

Sadly there is no cure for MS yet. Perhaps the most effective treatments currently available today deal with the autoimmune component of multiple sclerosis and work by regulating aspects of the immune system. They are known as the "ABC" treatments, where "A" stands for Avonex, "B" stands for Betaseron/Betaferon and "C" stands for Copaxone. A fourth drug Rebif has also been found essential in preventing relapse in treating RMMS.

Relapsing/Remitting Multiple Sclerosis (RRMS) is one of four internationally recognised forms of Multiple Sclerosis.

RRMS is characterised by relapses (also known as exacerbations) during which time new symptoms can appear and old ones resurface or worsen. The relapses are followed by periods of remission, during which time the person fully or partially recovers from the deficits acquired during the relapse.