全身型重症肌无力的临床和电生理特点分析

Analysis of clinical and electrophysiological characteristics of generalized myasthenia gravis

目的探讨不同亚型全身型重症肌无力(Myasthenia gravis,MG)临床和电生理特点之间的区别,并分析电生理结果与疾病严重程度的相关性。方法回顾性分析2016年7月至2020年7月在香港大学深圳医院神经内科就诊或住院的101例全身型MG患者的临床和电生理资料,按照其临床特点,分为早发乙酰胆碱受体(Acetylcholine receptor,AchR)抗体阳性全身型MG组(52例)、晚发AchR抗体阳性全身型MG组(23例)、胸腺瘤型MG组(22例)和肌肉特异性受体酪氨酸激酶(Muscle-specific receptor tyrosine kinase,MuSK)抗体阳性型MG组(4例),比较不同亚组MG患者的人口学特点、重症肌无力评分(Quantitative Myasthenia Gravis score,QMGs)、美国重症肌无力协会(MG Foundation America,MGFA)临床分级、重复神经电刺激(Repetitive nerve stimulation,RNS)结果,分析RNS结果与QMGs之间的相关性。结果非MuSK抗体阳性全身型MG中,早发AchR抗体阳性全身型MG女性患者所占比率最高(71.2%vs 65.2%vs 36.4%,P<0.05),胸腺瘤型MG呼吸肌/球部肌肉受累为主患者所占比率最高(28.8%vs 43.5%vs 63.6%,P<0.05),早发AchR抗体阳性全身型MG被检肌肉RNS均为阳性患者所占比率最高(44.2%vs 17.4%vs 22.7%,P<0.05),QMGs与RNS最大波幅下降比率、RNS总波幅下降比率呈明显正相关关系(P<0.01);MuSK抗体阳性全身型MG,其中重度受累患者所占比率、呼吸肌/球部肌肉受累为主患者所占比率均较高(均为75%),而被检肌肉RNS均为阳性患者所占比率较低(0%)。结论不同亚型全身型MG的人群分布、性别占比、主要受累肌肉、受累肌肉受累程度及分布范围均具有显著的差别,这在全身型MG的分型诊断方面具有很大的参考价值;其RNS结果与疾病严重程度具有高度相关性,提示RNS在全身型MG的病情评估方面具有重要临床价值。

Objective To explore the differences of clinical and electrophysiological characteristics of different subgroups of generalized myasthenia gravis(MG),and analyze the correlation between electrophysiological results and disease severity.Methods A retrospective analysis of 101 generalized MG patients who accepted diagnosis and treatment in the department of neurology of Shenzhen Hospital of Hongkong University from July 2016 to July 2020 was performed.According to their clinical feature,these patients were divided into early-onset generalized MG group with Acetylcholine receptor(AchR)antibodies(52 cases),late-onset generalized MG group with AchR antibodies(23 cases),thymoma-associated MG group(22 cases)and MuSK associated MG group(4 cases).We compared the demographic characteristic,Quantitative Myasthenia Gravis score(QMGs),MG Foundation America(MGFA)Clinical Classification,repetitive nerve stimulation(RNS)results of different subgroups and analyze the correlation between RNS results and QMGs.Results In different subgroups of generalized MG without positive MuSK antibodies,the rate of female patients of early-onset MG with AchR antibodies was highest(71.2%vs 65.2%vs 36.4%,P<0.05),the rate of patients with respiratory/bulbar muscles dominantly impaired of thymoma-associated MG was highest(28.8%vs 43.5%vs 63.6%,P<0.05),the rate of patients with RNS positive of whole muscles detected of early-onset MG with AchR antibodies was highest(44.2%vs 17.4%vs 22.7%,P<0.05),the positive correlation between QMGs and highest or whole RNS decrement was demonstrated(P<0.05);In MuSK associated MG,the rate of patients with respiratory/bulbar muscles dominantly impaired or moderately and severely impaired were relatively higher(both 75%),the rate of patients with RNS positive of whole muscles detected were relatively lower(0%).Conclusion The population distribution,gender proportion,dominantly impaired muscles and severity and distribution of impaired muscles of different subgroups of generalized MG were significantly different,which would be valuable in the classification diagnosis of generalized MG;The high correlation between RNS results and disease severity existed,which demonstrated the significant values of RNS in severity evaluation of generalized MG.