多发性肌炎和皮肌炎38例的临床与肌电图分析

目的 探讨多发性肌炎（PM）和皮肌炎（DM）患者的临床与肌电图特征.方法 对38例PM和DM患者的临床与肌电图的特征进行回顾分析.结果 临床症状以肌肉无力最为多见（88.0%）,其他依次为皮肤损害（31.0%）,发热（10.5%）.肌电图检查示肌源性损害32例,神经源性损害1例,异常率为86.8%.主要表现为插入电位延长（9.5%）、出现自发电位（52.3%）;MUP时限缩短（74.6%）、MUP波幅降低（6.3%）,多相波增多（34.1%）;重收缩时波型异常（44.4%）及峰值波幅降低（37.3%）.股四头肌、胫前肌及胸锁乳突肌阳性率显著高于拇短展肌组.胫前肌组MUP时限缩短的阳性率及多相波增多阳性率均表现最高.结论 肌电图检查是诊断PM和DM的重要手段,选择胸锁乳突肌、胫前肌及股四头肌进行EMG检查阳性率最高.

Analysis of clinical manifestation and EMG in 38 patients with polymyositis and Dermatomyositis

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 38 patients with PM and DM. Resuits The most common first onset symptoms were muscular weakness in limbs （88.0%） in patients with PM,DM, the other symptoms were orderly dermal damage （31.0%） and fever （ 10. 5% ） and EMG showed myogenic changes in 32 cases and neurogenic damages in 1 case. The abnormality rate was 86. 8%. EMG abnormalities mainly showed prolonged insertion potential （ 9. 5% ）, increased spontaneous potential （ 52. 3% ）, decreased MUP duration （74. 6% ） and amplitude （6. 3% ） as well as increased polyphasie ware （34. 1% ）. The abnormality rate of waveform was 44. 4%, and the positive rate of decreased peak amplitude was 37.3% in heavy contraction. The positive rate of spontaneous activity of quadriceps, sernodeidomastoid and ante-riot tibial muscles was aignificanfly higher than that of short abductor mnsdes of thumb. The highest positive rate of decreased MUP duration and increased polyphasic waves was found in anterior tibial mnseIes. Conclusion EMG might be an important mean of diagnosing PM and DM. Sdection of quadfieeps, sernocleidomastoid and tefiofibial muscles for EMG might be helpful in increasing the positive rate of EMG.