Myasthenia gravis

Myasthenia gravis, disease of the junctions between the peripheral nerves and the muscles, probably due to abnormal immunity and characterized by muscle fatigue. It commonly affects eye muscles, leading to drooping lids and double vision, but it may involve limb muscles. Weakness of the muscles of respiration, swallowing, and coughing may lead to respiratory failure and aspiration or bacterial pneumonia. Speech is nasal, regurgitation into the nose may occur, and the face is weak, lending a characteristic snarl to the mouth. It is associated with disorders of thymus and thyroid glands. Treatment is with cholinesterase inhibitors; steroids and thymus removal may control the causative immune mechanism.