重症肌无力患者电生理检查的特点

Electrophysiological characteristics of patients with myasthenia gravis

目的分析重症肌无力（myasthenia gravis,MG）患者重复神经刺激（repetitive nerve stimulation,RNS）和针电极肌电图（needle electrode electromyography,NEMG）检查结果的特点,探求电生理检查结果对于MG诊断的临床意义。方法收集2009年-2013年南京鼓楼医院神经科住院的50例MG患者的电生理资料进行分析研究。结果 50例MG患者中RNS检查结果阳性者40例（80%）。其中Ⅱ、Ⅲ和Ⅳ型阳性率较高,均超过90%;而Ⅰ型阳性率远低于其余3型,仅为40%,其差异有统计学意义（P〈0.01）。对不同神经RNS结果进行分析发现,刺激腋神经、面神经和尺神经时RNS阳性率分别为：60%、58%和16%;腋神经、面神经阳性率远高于尺神经,其差异有统计学意义（P〈0.01）。NEMG检查结果示,58%的患者呈肌源性损害表现,且随年龄增长,异常率升高。结论 RNS技术是诊断MG可靠的电生理方法,以面神经及近端腋神经异常率较高;MG患者容易出现肌源性损害,且与年龄有关,NEMG的使用有利于发现MG患者的肌源性损害,为临床诊断和治疗提供帮助。

Objective To analysis the characteristics of repetitive nerve stimulation（repetitive nerve stimulation,RNS） and needle electrode electromyography（ NEMG） in patients with myasthenia gravis（ MG）,and to explore the clinical significance of electrophysiological examination results for MG. Methods Analyze electrophysiological and clinical data of 50 patients with MG from 2009 to 2013 in Nanjing Drum Tower Hospital. Results RNS findings in 50 cases of patients with MG were 40 cases（ 80%） positive. Ⅱ,Ⅲ and Ⅳ type positive rate was higher,more than 90%; While the positive rate withⅠ type was far lower than that in the rest 3 types,was only 40%,the difference was statistically significant（ P〈0. 01）. This study also found that the RNS positive rate of stimulating the axillary nerve,facial nerve and ulnar nerve was60%,58% and 16%,respectively. The RNS positive rate of Axillary andfacial nerve was much higher than that of ulnar nerve,the difference was statistically significant（ P〈0. 01）. We also showed that most patients had shorter motor unit action potential（ motor unit action potential,MUAP） time,reduced raise abnormal phase and amplitude and a few patients with impaired muscle performance or with spontaneous potential by NEMG test. Conclusion RNS technology is a reliable electrophysiological method for diagnosis of MG. RNS diagnostic sensitivity of patients with MG belongs to the clinical types and detection area. NEMG examination in patients with MG,the main results of MUAP time shortened,raise phase anomalies and reduce volatility.