Myasthenia gravis complicated with polymyositis: a report of three cases and literature review

Three female patients admitted with elevated creatine kinase, impaired muscle on electromyogram, and positive repetitive nerve stimulation and neostigmine tests were diagnosed as polymyositis (PM) with myasthenia gravis (MG). Twenty five more cases were retrieved by literature search, and the clinical data of total 28 cases were analyzed. There were 10 males and 18 females with an average age of 56 years. The clinical manifestations include dyspnea(43%), dysphagia(43%), ptosis(43%), dysarthria(29%), diplopia(18%), cough after drinking(14%), myalgia(11%). Thirteen out of 26 cases (50%) had positive results in repetitive nerve stimulation (RNS) and 10/11 showed positive reaction in neostigmine test. Serum positive anti-acetylcholine receptor was detected in 21 out 23 patients (91%). Key words: Polymyositis; Myasthenia Gravis