Myasthenia Gravis

Myasthenia gravis is a rare disease characterized by excessive fatigability of muscles, especially marked in certain characteristic groups. The ocular muscles are usually first involved and there is unilateral or bilateral ptosis of the eyelids, diplopia, occasionally strabismus and a fixed eyeball, which makes it necessary for the patient to turn the body rather than the eyes in order to see objects at one side. The muscles of mastication and deglutition are frequently involved early, and the jaw sags soon after the patient starts to chew. There is strangling and difficulty in swallowing. The voice weakens rapidly, the muscles of expression tire and a masklike expression results. In more severe cases there are attacks of rapid, shallow breathing when the accessory respiratory muscles or the diaphragm are involved, and weakness of the cardiac muscle may result in palpitation and tachycardia. The involvement of the muscles of the trunk and upper