重症肌无力两例误诊分析

Misdiagnosis Analysis of Myasthenia Gravis: Two Cases Report

背景重症肌无力(MG)是累及神经肌肉接头的自身免疫性疾病,临床典型表现为骨骼肌群波动性和易疲劳性的肌无力症状,不典型MG易被误诊,延误治疗时机。目的加强对不典型MG的认识,减少误诊率。方法对2例MG患者的临床特点、治疗、预后以及误诊情况进行分析。结果病例1,72岁女性,表现为急性起病的多组脑干症状,伴体位性眩晕和排尿异常,病初被误诊为后循环进展性卒中或高颈段脊髓病变,最终结合患者单纤维肌电图Jitter波增宽伴传导阻滞,胸部CT提示胸腺增生,溴吡斯的明及丙种球蛋白免疫治疗有效,诊断为MG;病例2,27岁男性,表现为面部感觉异常等多组颅神经支配区受累症状及脑脊液蛋白-细胞分离,多次被误诊为多颅神经炎,最终结合血清RyR抗体和Titin抗体阳性,单纤维肌电图Jitter波增宽伴传导阻滞,胸部CT及病理提示B3型胸腺瘤,诊断为MG。结论 MG肌无力以外的症状表现多样,值得临床医生关注,对这种不典型表现的分析有助于加深对MG发病机制的理解。

Background Myasthenia gravis（ MG） is an autoimmune disorder with predominantly neuromuscular junction involvement,the typical clinical manifestations were symptoms of muscle weakness,such as volatility and fatigability of skeletal muscles. Atypical MG can easily be misdiagnosed,thus the treatment is delayed. Objective To improve the understanding of atypical MG,so as to decrease the misdiagnosis rate. Methods The clinical manifestation,therapeutical and prognostic profile as well as misdiagnosis reasons of two MG patients were analyzed. Results Case 1,72- year old female,abrupt onset of multi- brainstem symptoms combined with positional vertigo and urination disorder,the case was diagnosed with progressive stroke for posterior circulation or high cervical spinal cord disorder initially. According to wide Jitter wave and conduction block of single fiber electromyography,chest CT suggests thymic hyperplasia,and immune therapy（ pyridostigmine bromide and intravous immunoglobulin） was effective,the case was diagnosed with MG; case 2,27- year old male,suffered from multi- cranial nerve disorder including facial paresthenia,along with protein- cell separation in cerebrospinal fluid,the case was diagnosed with multiple cranial neuropathy more than once. According to seropositive RyR antibody and Titin antibody,wide Jitter wave and conduction block of single fiber electromyography,as well as chest CT and pathology suggest B3 type thymoma,the case was diagnosed with MG. Conclusion MG has diverse clinical manifestations except for myasthenia,clinicians should pay more attention to these,analysis of atypical clinical manifestations may enhance understanding of the pathogenesis of MG.