Abstract: Objective　To explore the clinical features，diagnosis，treatment and prognosis of rapidly progressive myasthenia gravis（MG） with pyramidal tract damage and nystagmus.Methods　We discussed the clinical manifestations，diagnosis，treatment and prognosis，and pathogenesis of MG with pyramidal tract damage and nystagmus on the basis of analyzing the clinical data of one case who visted Xuanwu Hospital Capital Medical University in March 28，2018 of this disease with rapidly progression treated by us as well as reviewing the related studies.Results　Our patient presented with ptosis and diplopia as the first symptoms.Then her conditions progressed rapidly to fatigable weakness of binocular and limb muscles which were mild in the morning but became severe in the afternoon or evening，with pyramidal tract damage and nystagmus.Further，positive neostigmine test results and decremental responses to low-frequency repetitive nerve stimulation test confirmed that she had MG.After being treated by pyridostigmine，intravenous immunoglobulin pulse therapy，hormone and methotrexate，the patient recovered completely after three months.Conclusion　MG may lead to other systemic damages besides injuries on the neuromuscular junction.So it may be an autoimmune disease related to anti-acetylcholine receptor antibody（AChR-Ab） that can involve the entire nervous system.Its pathogenesis may be associated with the combination of AChR-Ab and AChR in the central and peripheral nervous system.Early immunotherapy can achieve a good prognosis.Clinicians' understanding of this disease should be increased，in order to reduce the possibilities of misdiagnosis or missed diagnosis.

Key words: Myasthenia gravis；Pyramidal tracts；Nystagmus, pathologic；Signs and symptoms；Prognosis

摘要： 目的　探讨伴锥体束损害及眼震快速进展型重症肌无力（MG）的临床特点、诊断、治疗及预后。方法　通过分析1例2018-06-28于首都医科大学宣武医院就诊的伴锥体束损害及眼震快速进展型MG患者的临床资料，结合文献回顾性分析伴锥体束损害及眼震MG的临床特点、诊断、治疗过程及预后，并探讨其发病机制。结果　本例患者以双眼睑下垂及复视为首发症状，快速进展至球部及四肢无力，晨轻暮重，伴锥体束损害及眼震。新斯的明试验阳性，重频电刺激低频递减，确诊为MG。经溴吡斯的明、丙种球蛋白冲击、激素及甲氨蝶呤治疗后，患者于3个月后完全恢复。结论　MG可出现神经肌肉接头以外的其他系统损害，考虑MG可能是一种抗乙酰胆碱受体抗体（AChR-Ab）相关的全神经系统均可受累的自身免疫性疾病，而非单一神经肌肉接头受累所致。其发病机制可能与AChR-Ab与中枢及周围抗乙酰胆碱受体（AChR）结合有关，早期经免疫治疗预后较好，临床上需提高对该病认识，避免误诊漏诊。

关键词: 重症肌无力；锥体束；眼震, 病理性；体征和症状；预后