Multiple Sclerosis

What is Multiple Sclerosis (MS)?

MS is a disabling neurologic disorder of young adults, affecting at least 300,000 Americans. The average age at diagnosis is 30, typically starting between ages of 15 and 50. Women are affected at least twice as often as men. It is more common in persons of northern European heritage and those living furthest from the equator. MS involves inflammation within the central nervous system followed by the loss of the protective myelin sheaths that surround nerve fibers. When myelin is damaged, nerve impulses are not quickly and efficiently transmitted. Besides damage to the myelin sheaths, it is now recognized that the nerve fibers, called axons, also are damaged in MS to varying extent. Lesions develop in the brain and spinal cord and can cause the symptoms of MS listed below.

What are the symptoms?

There are several types of MS. Most people with MS begin with relapsing-remitting disease. This means that the symptoms come and go, often leaving the person feeling nearly normal until another relapse, or MS attack, occurs. Symptoms associated with relapses usually develop over a period of days. The problems can last for a matter of days or weeks and then go away, sometimes even without any treatment. New attacks occur at irregular intervals, usually one attack every 1 to 2 years. Common symptoms include the following:

• Vision loss
• Numbness
• Weakness or fatigue
• Unsteadiness in walking
• Double vision
• Heat intolerance
• Partial or complete paralysis
• Electric shock sensations when bending neck

About 50% of patients with relapsing-remitting MS develop a progressive form of MS, called secondary progressive MS, in which there is continual worsening. In this phase of the disease, patients may continue to have relapses or may stop having them altogether. About 15% of patients have progressive worsening from the beginning of their MS and do not experience relapses of MS. This form of MS is called primary progressive MS.

How is MS diagnosed?

The diagnosis of MS is based on a history of multiple attacks over time of neurologic lesions that affect different parts of the central nervous system. A neurologist will order tests that will help confirm the diagnosis. Usually a magnetic resonance imaging (MRI) scan of the brain is ordered to find evidence of abnormal areas. Lumbar puncture is also helpful to detect specific problems with the cerebrospinal fluid.

What causes MS?

The cause of MS is unknown. There is strong evidence that MS is immune mediated. This means that the person's own immune system attacks the central nervous system.

What are the treatments?

Currently, there is no prevention or cure for MS. However, this is a promising time for people with MS, as several new medications that affect the underlying disease process have been approved or are awaiting approval by the US Food and Drug Administration (FDA). You should ask your neurologist about the best treatment options for you. Current treatments are divided into three categories:

1. Medications that treat the symptoms of MS. These include medications to treat depression, decrease muscle stiffness, reduce fatigue, control bladder symptoms, reduce pain, and address sexual dysfunction.
2. Medications that modify attacks when they occur. These are primarily corticosteroids that can shorten an attack.
3. Medications that modify disease activity. These are taken on a regular basis to help reduce the frequency of attacks and the long-term damage to brain caused by MS. FDA-approved disease modifying therapies for treating MS include recombinant B-interferons and immunosuppressant/chemotherapy drug, mitoxantrone.

© American Academy of Neurology