Multiple Sclerosis

Background

Multiple Sclerosis (MS) is an autoimmune disease of the central nervous system which is made up of the brain, spinal cord and optic nerves. A fatty tissue called myelin surrounds and protects the nerve fibers of the central nervous system that helps nerve fibers conduct electrical impulses throughout the body. In MS, myelin is damaged in many areas — known as plaques or lesions — and the scar tissue that develops as a result is called sclerosis. When myelin or the nerve fiber is damaged, the ability of the nerves to conduct electrical impulses and tell the body what to do is disrupted.

MS affects approximately 250,000 to 350,000 people in the United States. Most people experience their first symptoms between 20 and 40 years of age. In general, women are twice as likely to develop MS than men. Whites are the most likely to develop MS, and the disease is five times more prevalent in temperate climates than in tropical regions.

There are four different disease courses in MS, referred to as Relapsing Remitting (RR), Primary Progressive (PP), Secondary Progressive (SP) and Progressive-relapsing (PR). About 20 percent of the MS population has a benign form of the disease where there is little to no progression of symptoms after the initial attack and patients remain functional.

Causes

Although scientists have learned a great deal about MS in recent years, the exact cause of MS is unknown. Many investigators believe that damage to myelin occurs as a result of an abnormal response by the body’s immune system, in which the body launches a defensive attack against its own tissues. Most agree that this autoimmune attack is a result of different factors, including a person’s genetics, along with exposure to an unknown environmental trigger such as a virus.

Symptoms

The range of symptoms in MS varies dramatically from person to person and depends on the area of the nervous systems that is affected. The initial symptom of MS is often blurred or double vision, red-green color distortion or even blindness in one eye. Most people with MS experience muscle weakness in their extremities and difficulty with coordination and balance. Often, these symptoms can be severe enough to impair walking or standing.

Additional symptoms of MS may include:

  • Fatigue
  • Tremors
  • Changes in speech
  • Loss of bladder control
  • Vision changes
  • Depression
  • Impairment of pain, temperature or touch senses

Diagnosis

Since there is no single test that detects MS, diagnosis can be difficult. Doctors use a variety of tools to rule out other possible disorders and rely on a person’s history of symptoms, clinical examination and laboratory tests to aid in diagnosing MS.

Specific laboratory tests used to diagnose MS include:

Magnetic Resonance Imaging (MRI) — This is a painless, noninvasive test that helps locate central nervous system lesions that occur when myelin is damaged. An abnormal MRI does not necessarily mean a person has MS, since there are other diseases that cause lesions in the brain that look like those caused by MS. In addition, a normal MRI does not rule out MS because lesions can also occur in the spinal cord, or there may be lesions that can’t be detected by MRI.

Visual Evoked Potential (VEP) — The speed of the brain’s response to visual stimuli is measured in this test and sometimes lesions can be detected. Just like the MRI test, however, VEP is helpful but cannot conclude if a person has MS because it cannot identify the cause of the lesions.

Cerebrospinal Fluid (the colorless liquid that circulates throughout the brain and spinal cord) — The examination of the CSF can show any cellular or chemical changes that are often associated with MS. These include high amounts of white blood cells, proteins such as myelin basic protein and an antibody called immunoglobulin G.

Treatment

Specialty drug list

There is no cure for MS; however, there are medications available to help manage the disease. The goals of therapy are to improve recovery from attacks, to prevent or lessen the number of relapses and to stop the disease from progressing.

There are different types of treatment a physician can prescribe for MS. In the past, physicians have prescribed steroids such as IV methylprednisolone as the principal medication for patients experiencing acute relapses. Steroids can reduce the time and severity of attacks in some patients. Interferons are another type of treatment that help to lower the number of exacerbations a patient may experience and may slow the progression of physical disability. Additionally, immunosuppressants and monoclonal antibodies are used to help alter a patient’s immune response to the disease.

Side Effects

Treatment can cause side effects, but it is important that a person never change their dosage or stop taking their medication without talking to their doctor or pharmacist.

Common side effects for the different treatment options for MS include:

Steroids
Weight gain, increased appetite, anxiety, nervousness and increased risk of infection
Interferons
Headache, fever, chills, injection site pain, depression and increased risk of infection
Immunosuppressants
Constipation, cough, diarrhea, loss of appetite, nausea, tiredness, vomiting and weakness
Monoclonal antibodies
Headache, feeling tired, joint pain, depression, diarrhea, stomach pain and increased risk of infection

Resources

There are many resources and organizations available to help, providing support, advocacy and information:

National Multiple Sclerosis Society

Multiple Sclerosis Foundation

Multiple Sclerosis Association of America

References

National Institutes of Health. NINDS. Multiple Sclerosis: Hope Through Research Handout. NIH Publication No. 96-75.August 19, 2011.