Main Article Content
Objective : To study prevalence and clinical features of myasthenia gravis (MG) and myasthenia gravis with hyperthyroidism (MGHT)
Design : Case review study
Setting : Srinagarind hospital, Faculty of Medicine, Khon Kaen University
Patienes : One hundred and four patients who were diagnosed as MG and MGHT in Department of Internal Medicine service between Januay 1891 and May 1992.
Measurement : Prevalence of MGHT, history of fatigability, fluctuation, staging, symptoms and signs, prostigmine test and treatment by thymectomy in MG and MGHT by percentage and Z – test ( P = 0.05)
Results : One hundred and four records were available for review, there were 85 cases of MG and 19 cases of MGHT that made the prevalence of MGHT of 18.3%. Regarding the staging of disease, in MG group of patients only 8.2% were in stage I compared to 31.6% in MGHT group( P = 0.003). Ninty four percent of MGHT patients seeked medical attention within 1 year after having MG, but there were only 77.2% in MG patients ( P = 0.048). Concerning thymectomy, in the patients who had stage IIA and above, 58 / 78 (74.4%) were thymectized in MG group. There were only 5/13 (38.5%) in MGHT group went for thymectomy (p = 0.048). The other clinlical features were comparable. The pathological findings of 50 patients in MG group were thymic hyperplasia 34 cases (68%) , htymoma 2 cases, malignant thymoma 1 case atrophic change 5 cases and normal 8 cases. In MGHT goup were thymic hyperplasia 4 cases and involuted 1 case.
Concludions : The prevalence of myasthenia gravis with hyperthyroidism in our study is 18.3%, which probably is the highest among all series. There were differences in some clinical features between MG and MGHT. MGHT patients were in stage 1 more frequent, seeked medical aedical altention earlier and MGHT patients went for thymectomy less frequent.