What is myasthenia gravis?

• A. Autoimmune neuromuscular disease affecting motor cranial nerves
• B. Degenerative brain disease
• C. Inflammatory spinal cord disease
• D. Muscular dystrophy

Answer: (A)

Myasthenia gravis is an autoimmune condition that disrupts communication between nerves and skeletal muscles at the neuromuscular junction. Antibodies attack acetylcholine receptors on the muscle side, so nerve signals don’t produce strong contractions. This causes fatigable weakness that worsens with activity and improves with rest, and it often first appears with the muscles around the eyes and face, sometimes extending to swallowing and speaking.

It’s not a brain disease, nor an inflammatory spinal-cord condition, nor a primary muscular dystrophy. The hallmark is autoimmune damage at the neuromuscular junction, leading to impaired transmission to the muscles rather than degeneration of brain tissue, the spinal cord, or the muscles themselves.