皮肌炎患者的临床表现与肌电图观察

目的 探讨皮肌炎（DM）患者的临床表现与肌电图特征。方法 对临床确诊的42例DM的临床与肌电图特征进行分析。结果 首发症状以皮肤损害为最多见（占40％），其它依次为肌肉无力、发热。血清酶检测以肌肉磷酸激酶（CPK）升高最明显，肌电图检查示肌源性损害34例，神经源性损害2例，异常率为86％。主要表现为插入电位延长（10％）、出现自发电位（53％），MUP时限缩短（76％）、MUP波幅降低（8％），多相波增多（35％），重收缩时波形异常（46％）及峰值波幅降低（38％）。股四头肌、胫前肌及肱二头肌组阳性率显著高于外展拇短肌（P〈0．05），胫前肌组MUP时限缩短阳性率最高，多相波增多阳性率胫前肌组最高。结论 肌电图检查是诊断DM的重要手段，选择股四头肌、胫前肌及肱二头肌进行EMG检查阳性率最高。

Analysis of clinical manifestation and EMG in patients with dermatomyositis

Objective To investigate the clinical and EMG features in patients with dermatomyositis (DM). Methods The clinical and EMG features were analyzed in 42 patients with DM. Results The most common first onset symptoms were dermal damage (40%) in patients with DM, and the other symptoms were orderly muscular weakness in limbs and fever. CPK was most highest enzyme in blood serum. EMG showed myogenic changes in 34 cases and neurogenic damages in 2 ones. The abnormality rate was 86%. EMG abnormalities mainly showed prolonged insertion potential (10%), increased spontaneous potential (53%), decreased MUP duration (76%) and amplitude (8%) as well as increased polyphasic potential. The abnormal rate of waveform was 46%,and the positive rate of decreased peak amplitude was 38% in heavy contraction. The positive rate of spontaneous activity of quadriceps, biceps and anterior tibial muscles was significantly higher than that of short abductor muscles of thumb respectively. The highest positive rate of decreased MUP duration and increased polyphasic waves was found in anterior tibial muscles. Conclusion EMG may be an important means of diagnosing DM. Selection of quadriceps, biceps and anterior tibial muscles for EMG may be helpful in increasing the positive rate of EMG.