Sun Chenjing, Ren Zhuangzhuang, Miao Xiuling, Zheng Yanxu, Zhang Jun, Qi Xiaokun, Liu Jianguo, Qiu Feng
Senior Department of Neurology, The First Medical Center of PLA General Hospital, Beijing, China.
Navy Clinical College, the Fifth School of Clinical Medicine, Anhui Medical University, Hefei, 230032, Anhui Province, China.
Heliyon. 2024 Mar 27;10(7):e28893. doi: 10.1016/j.heliyon.2024.e28893. eCollection 2024 Apr 15.
Late-onset myasthenia gravis (LOMG) often has comorbidities, and its initial symptoms may be ignored or misdiagnosed as other diseases. There were few large surveys on LOMG. Our study aimed to summarize clinical characteristics of LOMG to improve the rate of correct MG diagnosis.
A retrospective cohort study included 240 LOMG patients with onset age ≥65 years old who were treated at PLA General Hospital from January 1, 2003 to January 1, 2023.
The male to female ratio was 1:1.2 ( = 0.699). MGFA clinical classification: Class I 31.3%, Class IIa 12.9%, Class IIb 51.3%, Class IIIa 0.8%, Class IIIb 0.8%, Class IV 0.4%, Class V2.5%. The onset symptom was ptosis in 78.8% and diplopia was in 18.8%. Swallowing dysfunction in the stage of LOMG was in 41.7%. The incidence of thymoma in LOMG was 14.2%. 85.4% of patients antibodies against the muscle acetylcholine receptor (AChR) are detected. The overall incidence of supramaximal repetitive nerve stimulation (Jolly test) was 57.1%, among which the highest positive rate (50.7%) was in the facial nerve. Jolly test of Class IIb was tested in the highest positive rate and Class I was in the lowest one (χ2 = 7.023, = 0.030).
There was no significant difference in the incidence of LOMG between males and females. The clinical manifestations were mainly Class I and Class II, and severe MG was rare. The most common onset symptom was ptosis. The incidence of LOMG with thymoma was low. Supramaximal repetitive nerve stimulation (Jolly test) of the facial nerve was the easiest to detect and Jolly test of Class IIb was tested in the highest positive rate and Class I was in the lowest one.
晚发型重症肌无力（LOMG）常伴有合并症，其初始症状可能被忽视或误诊为其他疾病。关于LOMG的大型调查较少。我们的研究旨在总结LOMG的临床特征，以提高重症肌无力的正确诊断率。
一项回顾性队列研究纳入了2003年1月1日至2023年1月1日在中国人民解放军总医院接受治疗的240例发病年龄≥65岁的LOMG患者。
男女比例为1:1.2（P = 0.699）。MGFA临床分类：I类31.3%，IIa类12.9%，IIb类51.3%，IIIa类0.8%，IIIb类0.8%，IV类0.4%，V类2.5%。发病症状中睑下垂占78.8%，复视占18.8%。LOMG阶段吞咽功能障碍占41.7%。LOMG中胸腺瘤的发生率为14.2%。85.4%的患者检测到抗肌肉乙酰胆碱受体（AChR）抗体。超强重复神经刺激（乔利试验）的总体发生率为57.1%，其中面神经的阳性率最高（50.7%）。IIb类的乔利试验阳性率最高，I类最低（χ2 = 7.023，P = 0.030）。
LOMG的发病率在男性和女性之间无显著差异。临床表现主要为I类和II类，严重的重症肌无力很少见。最常见的发病症状是睑下垂。伴有胸腺瘤的LOMG发病率较低。面神经的超强重复神经刺激（乔利试验）最易检测到，IIb类的乔利试验阳性率最高，I类最低。
