一次性同心圆针电极记录的单纤维肌电图对重症肌无力的诊断价值

The diagnostic value of single fiber electromyography recorded by single-use concentric needle electrodes in myasthenia gravis

目的:探讨一次性同心圆针电极记录的单纤维肌电图(SFEMG)对重症肌无力(MG)的诊断价值。方法:将76例诊断为MG的患者及匹配正常对照组进行重复神经电刺激(RNS)、SFEMG、乙酰胆碱受体抗体(AChR-Ab)以及常规肌电图测定。结果:MG组jitter平均值(46.6±21.5)μs,jitter>42μs者平均(19.5±16.8)%,阻滞平均(5.3±10.2)%,均显著高于正常对照组(P<0.001);SFEMG异常的阳性率86.8%,RNS异常的阳性率34.2%,AChR-Ab异常的阳性率71.1%,SFEMG与RNS、AChR-Ab的阳性率差异均有统计学意义(P值均<0.005)。结论:一次性同心圆针电极记录SFEMG在MG的诊断中价值较高,对比于RNS、AChR-Ab,具有较高的阳性率,但需注意三者互补并结合临床表现来提高确诊率。

Objective:To evaluate the diagnostic value of single fiber electromyography recorded by single-use concentric needle electrodes in myasthenia gravis(MG).Methods:76 patients clinically diagnosed as myasthenia gravis and the matched control group were subjected to repetitive nerve stimulation(RNS),SFEMG,antibody to the acetylcholine receptor(AChRAb)and electromyography.Results:In the group of MG,the mean jitter ranged(46.6±21.5)μs,and the ratios of jitter>42μs and blocking were(19.5±16.8)%and(5.3±10.2)%respectively,which were all significantly higher than those in the control group(P<0.001).The abnormal positive rate of SFEMG,RNS and AChRAb was 86.8%,34.2%and 71.1%respectively,the difference being significant(P<0.005).Conclusion:The value of SFEMG recorded by single-use concentric needle electrodes in the diagnosis of MG is high.Compared with RNS and AChRAb,there was a higher positive rate,but the three should be complemented on the basis of clinical manifestations to improve the diagnosis rate.