重症肌无力患者针电极肌电图肌源性受损表现的临床意义

目的分析重症肌无力(myasthenia gravis,MG)患者针电极肌电图(needle electrode electromyography,NEMG)检查结果的临床意义。方法回顾性分析2011-01-01—2013-12-31期间在解放军第309医院神经内科住院治疗的335例确诊MG患者的NEMG检查结果和临床资料,根据NEMG检查是否出现肌源性受损表现将患者分为两组,对比分析两组患者的临床特点。结果29例(8.7%)NEMG出现肌源性受损表现,异常NEMG均无自发电位,仅表现为运动单位电位(motor unit potential,MUP)波幅降低、时限缩短。NEMG检查有肌源性受损表现组临床绝对评分(20.8±7.3)高于无肌源性受损表现组(14.9±9.0,t=1.79,P0.05)。NEMG检查无肌源性受损表现者多以眼外肌无力为首发症状(85.62%),以肢体和球部肌肉起病者比例较低(14.38%);与无肌源性受损表现者相比,有肌源性受损表现者以眼外肌为首发症状者比例较低(55.17%),多以肢体和球部肌肉受累起病(44.83%),两组差异有统计学意义(χ2=9.79,P0.01)。两组间比较,性别、发病年龄、病程、Osserman分型及胸腺病理类型差异均无统计学意义(均P0.05)。结论 NEMG检测表现为肌源性受损者病情较无肌源性受损表现者重。电生理检查可在一定程度上提示MG病情的严重程度。

The clinical significance of myogenic damage in needle electrode electromyography for patients with myasthenia gravis

Objective To investigate the clinical significance of needle electrode electromyography (NEMG)test for myasthenia gravis (MG).Methods This retrospective study analyzed the results of NEMG and clinical data of 335 inpatients with definite MG who were treated at the 309th hospital of Chinese PLA between 2011 and 2013. The patients enrolled were divided into 2 groups according to whether the results of NEMG showed myopathic damage. And the clinical character of the 2 groups were compared.Results NEMG demonstrated that 29 patients (8.7%)showed myopathic changes,and none had spontaneous potentials. The myogenic damage only presented shorter durations and lower amplitude of motor unit potentials (MUP). Patients with myogenic damage had higher clinical absolute scores (20.8±7.3)than those without such changes (14.9± 9.0,t = 1.79,P < 0.05 ). Patients without myogenic damage usually got initial symptoms only involving extraocular muscles (85.62%) but limbs and bulbar muscles (14.38%). While, the ratio of extraocular muscles onset was relatively low (55.17%)in patients with myogenic damage,and most patients involved limbs and bulbar muscles at the onset of the disease (44.83%). There was statistical difference between the 2 groups (χ2 =9.79,P <0.01). Otherwise,there was no statistical difference in gender,ages at onset,course of disease,Osserman classification or thymus types. Conclusions Some patients with MG may show myogenic damage in NEMG test. Patients with myogenic damage showed more sever clinical symptoms. Electrophysiological tests can indicate MG severity to some extent.