Myasthenia Gravis

WHAT YOU SHOULD KNOW

In this rare disease, the nerves controlling the muscles suffer a decline in their ability to stimulate movement, leading to muscle weakness and fatigue. Typically, the problem first appears in the muscles of the face and throat, including those that control eye movements, chewing, swallowing and coughing. Later, the weakness may spread to the limbs. Although the muscles do not wither and waste away as they do in other neuromuscular disorders, such as Lou Gehrig's disease, they do slowly become paralyzed over time.

The severity of this condition varies from day to day, even hour to hour. Severe weakness, for example, may be followed by a period of remission a few hours later. In most people, the weakness tends to be worse at night.

This disorder most commonly strikes women between the ages of 20 and 40, and men older than 40.

Causes

The culprit in this disease is the immune system, which for some unknown reason attacks and incapacitates certain receptors in the muscle tissue. The receptors it targets respond to the energizing chemical messenger acetylcholine. Without the stimulus of this chemical, the muscles become weak or immobile.

Some experts suspect that the disease may be linked to thyroid disorders. In addition, some people who develop myasthenia gravis also have a tumor in their thymus gland, which may contribute to the problem. This gland, located at the base of the neck, plays a vital role in the immune system.

Signs/Symptoms

In most sufferers, the eye muscles are the first to be affected. Early warning signs include drooping eyelids and double vision. Problems with speaking and swallowing are also common. As the disease progresses, you're likely to begin experiencing weakness in the arms and legs. In severe cases, the muscles needed for breathing may be affected.

Care

Although there is no cure for this disease, the symptoms can be relieved by drugs that increase the level of acetylcholine and restore nerve transmission to the muscles. However, these drugs often produce unpleasant side effects, such as abdominal cramps and diarrhea, resulting in the need for additional drugs to treat the adverse reactions. If you do not respond fully to the acetylcholine therapy, you may be put on steroids or other drugs that regulate the immune system.

When the disease begins to affect the entire body, surgery to remove the thymus gland (thymectomy) is usually recommended. It produces improvement in 4 out of 5 cases. During severe episodes, another option is a procedure called plasmapheresis. This treatment filters abnormal antibodies from your blood through a vein.

Risks

If the disease reaches the muscles that control breathing, the condition can be life-threatening.

WHAT YOU SHOULD KNOW

• Ensure that all the healthcare providers you deal with, including dentists, are aware that you have myasthenia gravis. Certain drugs may aggravate your condition. Antibiotics, narcotics, muscle relaxants, heart regulators, and anesthetics, for example, can make the weakness worse.
• Soften or blend foods as much as possible. Weak mouth and throat muscles make eating and drinking difficult.
• Raise the head of the bed, even during sleep, to make breathing and swallowing easier.

If You Are Undergoing Plasmapheresis...

• Get plenty of rest. This may require some bed rest and naps during the day in addition to at least seven hours of sleep at night.
• Avoid strenuous activities and over-exerting yourself until the treatments are completed.
• Ensure you get plenty of protein in your diet. Good sources include meats such as beef, turkey, and chicken, and diary products such as eggs and cheese.
• Avoid people with colds or other contagious viruses. This type of treatment can suppress your immune system.

Call Your Doctor If...

• You develop signs of hepatitis, such as fever, itchy skin, or a yellowing of the skin or whites of the eyes.
• You develop signs of low blood pressure such as dizziness.
• You develop signs of infection, such as red, itchy, or inflamed skin, around your plasmapheresis puncture site.

Seek Care Immediately If...

• It becomes difficult to breath or swallow
• You begin to have episodes of apnea (no breathing).
• You start to experience irregular heartbeats.

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