摘要目的 回顾分析全身型重症肌无力(gMG)患者在停用溴吡斯的明(PB)时间差异下(8h和18h以上)进行肌电图检测结果的不同特点.方法 收集2016年6月至2018年5月在中山大学附属第一医院住院的因疑诊为gMG进行肌电图检测,最终确诊为MG的患者111例,其中36例因病情危重仅停服PB8h,75例停服PB 18h以上,对两组的临床资料及肌电图检测数据进行分析.结果 (1)两组在首发部位(P=0.027)、电生理检测时受累部位(P=0.015)及QMG评分(P＜0.01)上差异有统计学意义.(2)电生理检测组内比较:停PB8h组面神经的低频RNS阳性率最高(94.4％);停PB 18h以上组副神经的低频RNS阳性率最高(60.0％).(3)电生理检测组间比较:停PB8h组的低频RNS阳性率(94.4％)高于停PB 18h以上组(70.7％),差异有统计学意义(x2=8.115,P=0.004).两组间面神经的RNS阳性率及面神经在不同频率(1 Hz、3 Hz、5 Hz)电刺激下波幅的递减值差异有统计学意义(P＜0.01).结论 (1)在gMG患者中,对面神经和副神经进行检测可提高RNS的阳性率.(2)PB在gMG患者不同肌群的敏感性有较大的差异,对面神经支配的眼轮匝肌影响最小.(3)病情危重的疑诊gMG患者需行低频RNS检测时,夜间服PB,服药后8h即次日早上行肌电图检测,病情恶化风险小,也可获得阳性结果.

abstractsObjective To retrospectively analyze the characteristics of the electromyography (EMG) study in generalized myasthenia gravis (gMG) patients.Methods A total of 111 gMG patients were enrolled.Patients were divided into two groups:36 severe patients discontinuing pyridostigmine bromide (PB) for 8 hours were included in 8 h group,and 75 g MG patients discontinuing PB for at least 18 hours were included in＞18 h group.The clinical information and EMG study data were collected and analyzed.Results There were statistically significant differences in the initial location of the myasthenia muscle (P=0.027),the affected muscle detected by the EMG (P=0.01S) and quantitative myasthenia gravis (QMG) score (P＜0.01) between the two groups.Comparisons in each group revealed that the highest positive rate of low-frequency repetitive nerve stimulation (RNS) of facial in 8 h group and＞18 h group was 94.4％ and 60.0％,respectively.Comparisons between the two groups showed that the positive rate of low-frequency RNS in 8 h group was significantly higher than that in＞l 8 h group (94.4％ vs 70.7％,X2=8.115,P=0.004).In particular,the positive rate of RNS in facial nerves and the extent of the amplitude decrease under different electrical stimulations (1 Hz,3 Hz,and 5 Hz) were dramatically higher in the 8 h group (P＜0.01).Conclusions For gMG patients,the facial and accessory nerve detection can improve the positive rate of RNS.Different muscles had various sensitivity to PB,and orbicularis oculi muscle seemed the least sensitive muscle to PB.For suspect MG patients in severe condition,only discontinuing PB medication for 8 h before low-frequency RNS testing can avoid the deterioration and also obtain similar positive rate.