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🦠microbiology review

Myasthenia gravis

Written by the Fiveable Content Team • Last updated September 2025
Written by the Fiveable Content Team • Last updated September 2025

Definition

Myasthenia gravis is an autoimmune disorder where antibodies attack acetylcholine receptors at the neuromuscular junction, leading to muscle weakness. It primarily affects voluntary muscles, especially those controlling eye and eyelid movement, facial expression, and swallowing.

5 Must Know Facts For Your Next Test

  1. Myasthenia gravis is caused by autoantibodies against nicotinic acetylcholine receptors or other proteins in the postsynaptic membrane.
  2. Symptoms include ptosis (drooping eyelids), diplopia (double vision), and generalized muscle weakness that worsens with activity.
  3. Diagnosis often involves tests like the edrophonium test, repetitive nerve stimulation, or anti-acetylcholine receptor antibody assay.
  4. Thymomas (tumors of the thymus gland) are associated with myasthenia gravis in some patients.
  5. Treatment options include anticholinesterase medications, immunosuppressive drugs, plasmapheresis, and thymectomy.

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