Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by varying degrees of weakness of the skeletal (voluntary) muscles of the body. Symptoms vary in type and intensity. The hallmark of myasthenia gravis is muscle weakness that increases during periods of activity and improves after periods of rest. Muscles that control eye and eyelid movements, facial expression, chewing, talking, and swallowing are often, but not always, involved. The muscles that control breathing and neck and limb movements may also be affected. Myasthenia gravis is caused by a defect in the transmission of nerve impulses to muscles. Normally when impulses travel down the nerve, the nerve endings release a neurotransmitter substance called acetylcholine. In myasthenia gravis, antibodies produced by the body's own immune system block, alter, or destroy the receptors for acetylcholine. The first noticeable symptoms of myasthenia gravis may be weakness of the eye muscles, difficulty in swallowing, or slurred speech. Myasthenia gravis is an autoimmune disease because the immune system--which normally protects the body from foreign organisms--mistakenly attacks itself.. It is not directly inherited nor is it contagious.
|Myasthenia Gravis Foundation of America, Inc.
355 Lexington Avenue
New York, NY 10017-6603
Tel: 800-541-5454 212-297-2156
|American Autoimmune Related Diseases Association
22100 Gratiot Avenue
Eastpointe, MI 48021-2227
Tel: 586-776-3900 800-598-4668
|Muscular Dystrophy Association
3300 East Sunrise Drive
Tucson, AZ 85718-3208
Tel: 520-529-2000 800-572-1717
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Last updated December 4, 2012