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multiple sclerosis Images (Click to view larger image)
Alternative Names
MS, demyelinating disease
Definition
Multiple sclerosis or MS is a lifelong autoimmune disorder that can cause severe disability. An autoimmune disorder is one in which the body produces antibodies that attack its own tissue. The antibodies produced in people with multiple sclerosis attack the brain and spinal cord. About 15,000 people in the Australia and 1.1 million people worldwide have MS.
What is going on in the body?
In multiple sclerosis the coating of nerve fibres, called myelin, becomes inflamed. The inflammation damages the myelin, and signals cannot be passed along to the nerve, which can also be damaged. Axons or the nerves themselves also become damaged. The disease is progressive, in other words, it is expected to get worse over time. In some people, the disease progresses quickly. In others, it progresses very slowly. There may be remissions, or periods when MS does not get worse, alternating with relapses, or periods when the disease worsens. The disease eventually causes irreversible disabilities. Multiple sclerosis cannot be cured and never goes away.
What are the signs and symptoms of the disease?
The symptoms are varied, depending on which nerves are affected. Early signs of multiple sclerosis may be subtle and can include: As the disease gets worse, other symptoms may develop, such as: - muscle spasms, which can be quite painful
- slurred speech and difficulty swallowing
- chronic pain, such as back and muscle pain
- visual loss, including blindness
- bowel and bladder problems
- sexual dysfunction
- paralysis
- trouble with thinking and memory
- depression
In a mild case of disease, the symptoms may be so subtle that others cannot even tell that anything is wrong. When the disease progresses and is severe, the person can become quite disabled, losing the ability to walk and take care of himself or herself.
What are the causes and risks of the disease?
The cause of multiple sclerosis is not known. There are 4 major scientific theories about the cause of MS: - Immunologic. It is generally accepted that multiple sclerosis is an autoimmune disorder.
- Environmental. Worldwide, MS seems to be more common around the 40th parallel in the Northern and Southern hemispheres and is more prevalent in northern Europe. A person who is born in one of these areas but moves to another area before adolescence has a lower risk of developing MS.
- Viral. It is possible that a viral infection can trigger MS.
- Genetic. Having a parent or sibling with MS significantly increases a person's risk of MS.
Some neurologists believe that multiple sclerosis develops because a person is born with a genetic predisposition to react to an environmental agent. When that person comes into contact with the environmental agent, the contact triggers an autoimmune response that causes multiple sclerosis.
What can be done to prevent the disease?
There is no known prevention for multiple sclerosis.
How is the disease diagnosed?
Multiple sclerosis is diagnosed when symptoms are noticed by the person or his or her doctor. There is no test that can specifically diagnose multiple sclerosis. A cranial MRI may show damage to the myelin coating in the brain. But some people with MS have a normal MRI.
A spinal tap may be done to obtain cerebrospinal fluid, which surrounds the spinal cord and brain. The fluid is examined for evidence of immune system problems. An evoked potential test, which studies electrical impulses, can be done to look for slowing of messages in different parts of the brain.
Multiple sclerosis is sometimes diagnosed by ruling out all other possible causes for the symptoms. The basic rule for diagnosing MS has 2 criteria: - 2 attacks of multiple sclerosis symptoms, at least 1 month apart
- more than one area of damage to the myelin sheath of the nerve, without evidence of other disease that could damage the myelin
What are the long-term effects of the disease?
Over the long term, the level of disability increases. People who have periods when the disease gets worse, then stabilises, may notice sudden changes in function. People who have a slow steady progression of the disease will have a gradual loss of function. With proper treatment, people may recover some lost function when the disease goes into remission.
A recent study showed that irreversible disability occurred earlier in individuals who had steady progression of the disease from the onset. People who had alternating relapses and remissions went longer before having irreversible disabilities. Once the irreversible disabilities started, however, they progressed at the same rate in both groups.
What are the risks to others?
Multiple sclerosis is not contagious and poses no risk to others, but it does tend to run in families.
What are the treatments for the disease?
Treatment has two main goals. The first is to stop or slow the immune system's attack on the myelin coating of the nerves. The second is to relieve the symptoms and help the person function as normally as possible.
The immune system is treated with medications. Some of the most commonly used medications for ongoing treatment of MS are: - glatiramer acetate
- interferon beta 1-a
- interferon beta 1-b
Other treatments include: - high doses of corticosteroids such as methylprednisolone to relieve inflammation during relapses
- plasmapheresis, or removal of plasma, which is then treated and put back or retransfused into the body
- medications for muscle spasms, including baclofen, diazepam, or botulism toxin
- medications for loss of bladder control, including oxybutynin
- medications for nerve pain, such as carbamazepine, diphenylhydantoin, or valproate
A rehabilitation program is important to maintain as much function as possible and prevent symptoms that can occur if the person is inactive. Rehabilitation may include physiotherapy, occupational therapy, and speech therapy. Physiotherapy can help a person regain strength and movement, and prevent injury from falls. Occupational therapy can help a person do things independently. For example, the person with MS can learn how to use specialised tools or devices, or to conserve energy. Speech therapy can help a person communicate more clearly and help with difficulty swallowing.
What are the side effects of the treatments?
Side effects vary, depending on the medication used, but may include drowsiness, stomach upset, and allergic reaction to the medication. Corticosteroids may cause a variety of side effects, particularly when used long term. Water retention, swelling, and increased blood sugar levels can occur.
There are no side effects from rehabilitation therapy, except for some temporary fatigue and muscle soreness. This is a normal part of a therapy program and does not mean that the multiple sclerosis is getting worse.
What happens after treatment for the disease?
Monitoring and treatment of multiple sclerosis is lifelong. The progression of MS can be slowed quite a bit with the medications. Treatment of symptoms, including medications and therapy, can help reduce disability.
How is the disease monitored?
Blood tests, including a full blood count or FBC and liver function tests, are used to monitor people who are taking certain medications. An individual with MS will have regular visits to a doctor, as well as various specialists. Any new or worsening symptoms should be reported to the appropriate doctor.
Author: Gerald C. McIntosh, MD
Reviewer: HealthAnswers Australia Medical Review Panel
Editor: Dr David Taylor, Chief Medical Officer HealthAnswers Australia
Last Updated: 1/10/2001
Contributors
Potential conflict of interest information for reviewers available on request |
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