Myasthenia Gravis (MG) : FAQ, Part 2

by Women's Health Information Center

(Page 2 of 2)

Edrophonium test. When this drug is injected, the weak eye muscles of people with MG will briefly get stronger.

Nerve conduction test/repetitive stimulation. This is a test of specific muscle fatigue by repetitive nerve stimulation.

Single fiber electromyography (EMG). In this test, pairs of single muscle fibers are stimulated by electrical impulses. It can detect impaired nerve-to-muscle transmission.

Computed tomography (CT) or magnetic resonance imaging (MRI). These tests can help identify an abnormal thymus gland or a thymus gland tumor.

What is the treatment for MG?

Today, MG can be controlled. There are several therapies available to help reduce muscle weakness. Most persons with MG have good results from treatment. In some people MG, like many other autoimmune diseases, may go into remission (a period of time without symptoms) and muscle weakness may disappear completely.

Remission or improvement can occur without treatment in some cases. According to the Muscular Dystrophy Association, up to 20 percent of person with MG may have complete remission of symptoms without any treatment, and another 20 percent may improve without treatment. These spontaneous improvements are more likely to occur during early stages of MG.

Treatment of MG may include:

Medications. Drugs used include cholinesterase inhibitors such as neostigmine and pyridostigmine. These drugs help improve nerve signals to muscles and increase muscle strength. Immunosuppressive drugs such as prednisone, cyclosporine, and azathioprine may also be used to suppress the production of abnormal antibodies. They must be used with careful medical followup because they can be associated with major side effects.

Thymectomy, the surgical removal of the thymus gland (which is abnormal in most persons with MG). This surgery is done for persons with MG who have tumors, as well as for individuals without tumors. It improves symptoms in more than half of individuals without tumors. It may cure some people with MG, possibly by re-balancing the immune system.

Other therapies sometimes used to treat MG during especially difficult periods of weakness include:

Plasmapheresis or plasma exchange. This is a procedure that removes abnormal antibodies from the blood.

High-dose intravenous immune globulin. This treatment temporarily interferes with the ability of the immune system to damage the nerve muscle junction. Treatment options for a person with MG depend on the severity of the weakness, which muscles are affected, and the person's age and other medical problems.

In a few cases, MG may cause severe weakness resulting in acute respiratory failure. But most people can expect to lead normal or nearly normal lives.

What is a myasthenic crisis?

A myasthenic crisis occurs when weakness affects the muscles that control breathing. This can create a medical emergency requiring a respirator to help the person breathe or measures to prevent a person from taking in, or aspirating, too much air into their lungs. In individuals whose respiratory muscles are weak, infection, fever, a reaction to medication, or emotional stress can trigger a crisis.

How can I help take care of myself if I have MG?

You can follow a few simple steps to help cope with the condition in your daily life. Plenty of rest and a well balanced, potassium-rich diet can help ease fatigue. Good sources of potassium include oranges, orange juice, and bananas. It is important to avoid overexertion, and if necessary, to rest the eyes or to lie down briefly a few times a day.

Is MG associated with other conditions?

Since it is an autoimmune disease, it may occur in combination with other autoimmune conditions such as rheumatoid arthritis, Sjorgrens syndrome, lupus, pernicious anemia, or autoimmune thyroiditis.

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