Myasthenia gravis is a rare condition, affecting only 1/75000. It is characterized by weakness and fatigue of the voluntary muscles due to impaired neuromuscular transmission at the acetylcholine receptor site. It is probably caused by an
autoimmune
mechanism leading to reduction of the available nicotinic acetylcholine receptors at the neuromuscular junction. A relationship between the thymus and myasthenia gravis was suggested by Weigert in 1901, and Blalock was the first to report the
efficiency
of thymectomy in the treatment of myasthenia gravis in 1939. Since that time, thymectomy has become increasingly important in managing patients with myasthenia gravis.
@ES Twelve patients with myasthenia gravis underwent thymectomy September 1987 and February 1993 and got the following results:
@EN 1. The sex distribution was 8 females and 4 males with ages ranging from 15 to 50 years(mean, 32.9 years).
2. Clinical manifestation of ocular symptoms were seen in all cases, dysphagia in 11(91.6%), extremity weakness in 10(83.3%), and dyspnea in 2(16.7%).
3. According to the modified Osserman's classification, 7 patients were in group IIb, 3 in IIa, 1 in I and IIc, respectively.
4. Histopathologic examination of the resected thymuses revealed thymic hyperplasia in 7 patients, benign thymoma in 3, and malignant thymoma in 2.
5. There were no perioperative or immediate postoperative deaths but one patient died about two months after the thymectomy due to respiratory failure.
6. During the follow-up period, 10 patients(83.3%) showed clinical improvement. Among them, 3 patients(25%) showed complete remission, 3(25%) showed marked improvement, and 4(33.3%) showed subjective improvement.
7. Among the 7 patients with thymic hyperplasia, clinical improvement was noticed in all cases. Among the 5 patients with thymoma, 3 patients showed improvement.
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