Myasthenia Gravis

Myasthenia gravis (MG), the most common of several diseases in which impairment has been localized to the neuromuscular junction, is an autoimmune disease that results in the defective transmission of nerve impulses to the muscles. Specifically, antibodies destroy, block, or alter the receptors for acetylcholine, a neurotransmitter. Without adequate acetylcholine, the muscle is unable to contract, and so individuals with MG present with physical and psychological impairments that impact daily functioning. Complaints include weakness without accompanying pain in the muscles that control eye and eyelid movement, swallowing, limb movement, breathing, and speech. If respiratory muscles weaken to a point where mechanical ventilation is needed to sustain life, an individual is considered to be in myasthenic crisis. The name, referring to grave muscle weakness (Latin and ...