Multiple sclerosis, abbreviated as 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. For reasons that are not fully understood, people with MS produce antibodies that attack the white matter in the brain and spinal cord.
What is going on in the body?
In multiple sclerosis, the myelin, the coating of the nerve fibers of the brain and spinal cord, becomes inflamed. The inflammation damages the myelin, stopping the signals from being passed along the nerve.
About 70% of the individuals with MS have what is called the relapsing-remitting ("RR" type) of MS. They have periodic relapses, or episodes where symptoms worsen. These relapses are followed by remissions, during which the person has partial or full relief from symptoms.
The remaining 30% of people with MS have chronic, progressive disease. Although there are several subgroups, most individuals with chronic, progressive disease have a disease course that worsens steadily over time.
What are the causes and risks of the disease?
The precise cause of multiple sclerosis is not known. There are four major components that are believed to play some role in the occurrence of MS:
Environmental. Worldwide, MS seems to be more common in North America, Europe, Australia, and New Zealand than elsewhere, and in Europe and North America it is more common north of the 40th parallel. A person who is born in one of these areas but moves to another area before adolescence has a lower risk of developing MS.
Genetic. Having a parent or sibling with MS significantly increases a person's risk of MS.
Immunologic. It is generally accepted that multiple sclerosis is an autoimmune disorder.
Viral. It is possible that a viral infection can trigger MS.
Some neurologists believe that MS develops because a person is born with a genetic predisposition to react to an environmental agent. When that person comes into contact with the agent, the contact triggers an autoimmune response that causes MS.
What can be done to prevent the disease?
There is no known prevention for multiple sclerosis.
How is the disease diagnosed?
Diagnosis of MS begins with a history and physical exam. There is no single test that can specifically diagnose MS. A MRI may show damage to the myelin coating in the brain or spinal cord. However, some people with MS have a normal MRI.
A spinal tap may be done to obtain cerebrospinal fluid, the fluid that surrounds the spinal cord and brain. The fluid is examined for evidence of inflammation. Various proteins and cells in the CSF, in combination with symptoms and signs, can help make the diagnosis of MS.
An evoked potential test studies electrical impulses. It can be done to look for slowing of messages in different parts of the brain. MS is sometimes diagnosed by ruling out all other possible causes for the symptoms.
The basic rule for diagnosing MS has two criteria:
Long Term Effects
What are the long-term effects of the disease?
Over the long term, the level of disability increases. People with the relapsing-remitting form of MS may notice sudden changes in function. People who have chronic, progressive MS will have a gradual loss of function. A recent study showed that irreversible disability occurred earlier in individuals who had chronic, progressive MS than those with the relapsing-remitting form.
Once the irreversible disabilities started, which they eventually do in almost everyone with MS, they progressed at the same rate in both groups. Death in people with MS is generally related to complications of their disabilities.
Common causes of death include:
bedsores that become infected
pulmonary embolus, or a blood clot that blocks the blood supply to the lungs
What are the risks to others?
Multiple sclerosis is not contagious and poses no risk to others. However, 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.
Some of the common immune system-enhancing medicines for ongoing treatment of MS are:
- glatiramer acetate
- interferon beta 1-a
- interferon beta 1-b
Other treatments include:
- antidepressant medicines to relieve depression and reduce the risk for suicide
- high doses of corticosteroids such as methylprednisolone to relieve inflammation during relapses
- medicines for loss of bladder control, including oxybutynin or tolterodine
- medicines for muscle spasms, including baclofen, tizanidine, or botulism toxin
- medicines for nerve pain, such as carbamazepine, diphenylhydantoin, or gabapentin
- plasmapheresis, or removal of plasma, which is then treated and put back or retransfused into the body
A rehabilitation program is important to maintain as much function as possible and prevent complications of disability. Rehabilitation may include physical therapy, occupational therapy, and speech therapy.
What are the side effects of the treatments?
Side effects vary depending on the medicine used. They may include drowsiness, stomach upset, and allergic reaction to the medicine. Corticosteroids may cause a variety of side effects, particularly when used long term. Water retention, swelling, and increased blood glucose levels can occur.
The only side effects from rehabilitation therapy are some temporary fatigue and muscle soreness. This is a normal part of a therapy program and does not mean that the MS 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 considerably with medicines. Treatment of symptoms, including medicines and therapy, can help reduce disability.
How is the disease monitored?
Blood tests, including a complete blood count (CBC) and liver function tests, are used to monitor people who are taking certain medicines. An individual with MS needs to make regular visits to a primary healthcare professional as well as to various specialists. Any new or worsening symptoms should be reported to the appropriate healthcare professional.