Thymectomy in late-onset myasthenia gravis.

Between 1977 and 1979, 12 consecutive patients with myasthenia gravis who were over the age of 55 years were treated by thymectomy. In all, their conditions improved clinically; 11 of the 12 became free of the generalized features of myasthenia gravis. Nine patients required no further medication. Acetylcholine-receptor antibody titers did not change significantly. Although five patients had atrophic thymus glands, their conditions also improved. We conclude that (1) thymectomy is a safe and effective therapy for patients with myasthenia gravis who are over the age of 55 years; (2) steroids and anticholinesterase agents are not essential in the management of late-onset myasthenia gravis; and (3) reduction in acetylcholine-receptor antibody titer is not essential for beneficial clinical response.