Zebra of the Week: Myasthenia gravis

Myasthenia gravis is a chronic autoimmune neuromuscular disease characterized by muscle weakness. The condition may be restricted to certain muscle groups, particularly those of the eyes (ocular myasthenia), or may become more generalized (generalized myasthenia gravis). Weakness tends to increase during periods of activity and improve after periods of rest. The condition results from a defect in the transmission of nerve impulses to muscles, which is due to the presence of antibodies against acetylcholine.