MS is a chronic disease that causes inflammation in the white matter of the central nervous system and ultimately destroys myelin, which is the protective sheathing that insulates and protects nerve cell fibers in the brain, optic nerve, and spinal cord. This causes inflammation and injury to the sheath and ultimately to your nerves, resulting in multiple areas of scarring (sclerosis).

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. The exact cause of MS is not known, but the disease appears to be caused when the immune system mistakenly recognizes the body's own myelin as a foreign substance.

Most people with MS can continue to lead a normal life, with minimal restrictions on their daily living activities and a normal life expectancy. In some cases, however, MS can be very debilitating, with the nerve damage slowing or blocking muscle coordination, visual sensation and other nerve signals. Throughout the course of the disease, people with MS experience occasional relapses, called exacerbations, followed by periods of remission.

Risk Factors

People of Northern European descent, especially those of Scandinavian heritage, may be genetically predisposed to MS.

The disease appears to run in some families. As many as 20 percent of people with MS have at least one affected relative. If you're a child or sibling of someone with MS, your risk of eventually contracting MS increases 20 to 40 times.

Environmental factors, including viruses and bacteria, may trigger the disease if you're susceptible to MS. Scientists believe that an environmental trigger on top of a genetic predisposition may explain why in identical twins, only one twin develops MS 70 percent of the time.

Symptoms

Symptoms of MS may be mild or severe, and of varying durations. Vision problems, such as blurred or double vision, red-green color distortion, and blindness in one eye are often the first noticeable symptoms. Additional symptoms include muscle weakness in the arms and legs, coordination and balance problems, and occasional numbness or tingling, as well as cognitive impairment such as concentration, memory, and judgment problems.

Diagnosing MS

There is no definitive test for MS. However, a neurologist may conduct a complete medical history and neurological examination to rule out other neurological conditions. Imaging techniques such as computed tomography (CT) scanning or magnetic resonance imaging (MRI) can view the lesions caused by MS. Magnetic resonance spectoscopy (MRS) is another imaging technique that may gather information about the biochemistry of the brain. Laboratory tests that examine the patient's spinal fluid and presence of oligoclonal bands in cerebrospinal fluid also may help diagnose MS.

Treating MS

Currently, there is no cure for MS. 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. Symptoms associated with MS flares can be treated with short courses of steroids, muscle relaxants and antidepressants to reduce fatigue. In order to prevent relapses, interferon beta (Avonex or Betaseron) or colpaxone can be administered. These drugs are genetically engineered copies of proteins that occur naturally in your body. They help fight viral infection and regulate your immune system. 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. In severe cases, immunosupressants such as cyclophosphamide or mitoxantrone can be used.