What best describes Myasthenia Gravis?

• A. Bacterial infection of the lungs
• B. Autoimmune or congenital neuromuscular disease
• C. Degenerative brain disorder
• D. Vascular cognitive impairment

Answer: (B)

Myasthenia Gravis is an autoimmune condition that affects the communication between nerves and muscles at the neuromuscular junction. Antibodies interfere with acetylcholine receptors or the transmission process, causing muscles to weaken with use and improve with rest. It can also be congenital in some rare forms, where genetic defects produce a similar disruption in transmission. The result is fluctuating, fatigable weakness that can involve the eyes, face, throat, and sometimes respiratory muscles.

This differs from a bacterial infection of the lungs (which would be pneumonia), a degenerative brain disorder (such as Alzheimer's disease), or vascular cognitive impairment (caused by reduced blood flow affecting thinking). The hallmark is the autoimmune or congenital disruption of neuromuscular transmission leading to weakness that worsens with activity.