Myasthenia gravis

Myasthenia gravis

Myasthenia gravis produces sporadic but progressive weakness and abnormal fatigability of striated (skeletal) muscles, which are exacerbated by exercise and repeated movement but improved by anticholinesterase therapy. Usually, this disorder affects muscles innervated by the cranial nerves (face, lips, tongue, neck, and throat), but it can affect any muscle group.

Myasthenia gravis follows an unpredictable course of periodic exacerbations and remissions. (See Coping with lifelong myasthenia gravis.) There is no known cure. Drug treatment has improved the prognosis and allows patients to lead relatively normal lives, except during exacerbations. When the disease involves the respiratory system, it may be life-threatening.


Myasthenia gravis causes a failure in transmission of nerve impulses at the neuromuscular junction. Such impairment may result from an autoimmune response, ineffective acetylcholine release, or inadequate muscle fiber response to acetylcholine.

Myasthenia gravis affects 3 in 10,000 people at any age and is more
common in young women and older men.

This disease may coexist with immune and thyroid disorders; about 15% of myasthenic patients have thymomas. Remissions occur in about 25% of patients.

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Jun 16, 2016 | Posted by in GENERAL & FAMILY MEDICINE | Comments Off on Myasthenia gravis

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