多发性肌炎和皮肌炎患者的临床与肌电图分析

Analysis of clinical manifestation and EMG in patients with polymyositis and dermatomyositis

目的 :探讨多发性肌炎 (PM)和皮肌炎 (DM)病人的临床与肌电图特征。方法 :对 74例PM和DM临床与肌电图特征进行分析。结果 :首发症状以肌肉无力为最多见 (占 3 4% ) ,其他依次为皮肤损害 (占 3 1% ) ,发热 (占 13 % )。肌电图检查示肌原性损害 64例 ,神经原性损害 2例 ,异常率为 89%。主要表现为插入电位延长 (9% )、出现自发电位 (5 2 % ) ;MUP时限缩短 (74% )、MUP波幅降低 (6% ) ,多相波增多 (3 4% ) ;重收缩时波型异常 (4 5 % )及峰值波幅降低 (3 7% )。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组 (P <0 0 5 ) ,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PM和DM的重要手段 ,选择股四头肌。

Objective:To investigate the clinical and EMG features in patients with polymyositis(PM) and dermatomyositis(DM).Methods:The clinical and EMG features were analyzed in 74 patients with PM and DM.Results:The most common first onset symptoms were muscular weakness in limbs(34%) in patients with PM,DM,the other symptoms were orderly dermal damage(31%)and fever(13%) and EMG showed myogenic changes in 64 cases and neurogenic damages in 2 ones.The abnormality rate was 89%.EMG abnormalities mainly showed prolonged insertion potential(9%),increased spontaneous potential(52%),decreased MUP duration(74%)and amplitude(6%)as well as increased polyphasic potential.The abnormality rate of waveform was 45%,and the positive rate of decreased peak amplitude was 37% 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.The highest positive rate of decreased MUP duration and increased polyphasic waves was found in anterior tibial muscles.Conclusion:EMG might be an important means of diagnosing PM and DM.Selection of quadriceps,biceps and anterior tibial muscles for EMG might be helpful in increasing the positive rate of EMG.