What Is Myasthenia Gravis (MG)?

Myasthenia gravis (MG) is an illness that causes muscles in the eyes, face, throat, arms, and legs to get weak and tired. Muscles that control breathing may also be affected. The worst weakness usually occurs during the first 3 years.

MG affects people of both sexes, all ages, and all ethnic groups. Women usually get MG in the late teens and 20s, and men usually get it after age 60. Progression of MG is extremely slow and most people lead full lives.

What Causes MG?

MG is an autoimmune disease. This means that the body’s immune system attacks itself. MG isn’t contagious or passed from parents to children. MG is more common in people with tumors of the thymus gland called thymoma. The thymus gland is located in the chest and is part of the immune system.

What Are the Symptoms of MG?

Symptoms may get better (remission) and then worsen (exacerbation). The time between remission and exacerbation varies. The major symptom is muscle weakness that gets worse when people are more active. Temperature, menstrual periods, illness, and stress can affect the weakness. Other symptoms are eye problems (double vision, droopy eyelids); problems chewing, speaking, or swallowing; drooling; and arm and leg weakness. One symptom, shortness of breath, can be very frightening.

How Is MG Diagnosed?

The health care provider will make a diagnosis from a complete physical examination, with tests of lungs, reflexes, and muscle weakness. A specialist may do more tests, including electromyography, Tensilon® test, blood test, and computed tomography (CT). Electromyography measures muscle electrical activity as they contract after nerve stimulation. In the Tensilon® test, medicine temporarily improves muscle strength in people with MG. CT will check for a tumor or enlargement of the thymus gland.

How Is MG Treated?

The treatment depends on how severe symptoms are, age, sex, and physical activity level. Medicines such as steroids and anticholinesterase drugs can help symptoms. Lifestyle changes such as eating a good diet and getting enough rest can also help. Rest briefly during the day (about 10 to 15 minutes), and avoid strenuous work that may make fatigue worse. Try to exercise daily, as advised by the health care provider and physical therapist. For double or blurred vision, see an eye health care provider, and don’t drive or use heavy equipment. If swallowing is a problem, try foods of different consistency to find out which is best. Often thin liquids such as juice and water are harder to swallow than thick ones. Manage stress better. Regular exercise may help with stress management. Avoid smoke and dust.

DOs and DON’Ts in Managing MG:
  • DO try to find a balance between rest and physical activity to prevent muscle weakness.
  • DO get physical therapy to keep muscles strong.
  • DO wear a medical alert bracelet or necklace that says you have myasthenia gravis.
  • DO take medicines as prescribed. Call your health care provider if you have problems with your medicines.
  • DO call your health care provider if you have shortness of breath or your symptoms worsen to include double vision, blurred vision, or weakness.
  • DON’T gain weight and become inactive.
  • DON’T use tobacco. It may worsen shortness of breath.

Contact the following source:

  • Myasthenia Gravis Foundation of America
    Tel: (651)917-6256, (800)541-5454
  • American Academy of Neurology

Copyright © 2016 by Saunders, an imprint of Elsevier, Inc

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