伴自发电位重症肌无力的临床及电生理特点

目的探究伴自发电位重症肌无力患者的临床及电生理特点。方法收集重症肌无力住院患者共90例,均行重复神经电刺激、针电极肌电图检查,其中6例出现自发电位,回顾性分析6例病例临床及电生理特点。结果 6例患者均确诊为全身型重症肌无力,其中胸腺瘤合并率为3/6。乙酰胆碱受体抗体均阳性且多数滴度较高,其他重症肌无力抗体均阴性。针电极肌电图可见自发电位,均伴运动单位时限缩窄,重复神经电刺激均见低频波幅递减、高频未见递增。结论本研究揭示了全身型重症肌无力患者的一种少见电生理表现,即以正锐波及纤颤电位为主的自发电位,可为严重神经肌肉接头异常所致。

The clinical and electrophysiological features of myasthenia gravis with spontaneous potential

Objective To investigate the clinical and electrophysiological features of patients with myasthenia gra?vis associated with spontaneous activity. Method Repetitive nerve stimulation and needle electromyography were per?formed on a total of 90 inpatients with myasthenia gravis. A retrospective analysis of clinical and electrophysiological fea?tures was conducted on 6 patients with abnormal spontaneous activity. Result All 6 patients were diagnosed as the general type myasthenia gravis. Three patients had thymoma. All the patients showed positive for acetylcholine receptor antibodies but not for other MG antibodies..The amplitude was decrement on low frequency (3~5 Hz) repetitive nerve stimulation whereas remained unchanged on high frequency (10~20 Hz) repetitive nerve stimulation. Electromyography demonstrated spontaneous activity accompanied by short-duration motor unit action potential. Conclusion This study has revealed a rare electrophysiological manifestation of patients with generalized myasthenia gravis, that is, spontaneous activity includ?ing positive sharp wave and fibrillation potential which may result from severe abnormality of neuromuscular joint.