Myasthenia gravis is a rare condition, affecting only 1/7500. 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 1991, and Blalock was the first to report the
efficiency
of thymectomy in the treatment of myasthnia gravis in 1939. Since that time, thymectomy has become increasingly important in managing patients with myasthenia gravis.
Fourteen patients with myasthenia gravis underwent thymectomy between September 1987 and
@ES March 1994 and got the following results;
@EN 1. The sex distribution was 10 females and 4 males with ages ranging from 15 to 51 years(mean, 34.8 years).
2. Clinical manifestation of ocular symptoms were seen in all cases, dysphagia in 12(85.7%), extremity weakness in 11(78.6%), and dyspnea in 3(21.4%).
3. According to the modified Osserman's classification, 8 patients were in group IIb, 3 in IIa, 2 in I and 1 in IIc, respectively.
4. Histopathologic examination of the resected thymuses revealed hyperplasia in 8 patients, benign thymoma in 3, and malignant thymoma in 3.
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, 11 patients(78.6%) showed clinical improvement. Among them, 4 cases(28.6%) showed complete remission, 3(21.4%) showed marked improvement, and 4(28.6%) showed subjective improvement.
7. Among the 8 patients with thymic hyperplasia, clinical improvement was noticed in 7 patients (5%). Among the 6 patients with thymoma, 4 patients(66.7%) showed improvement. (Korean J Thoracic Cardiovas Surg 1994; 27:610-6)
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