目的

探讨1 例肯尼迪病（KD）合并血清抗体阴性重症肌无力（SNMG）患者的临床诊断特征。

方法

回顾性分析2024 年6 月25 日徐州医科大学附属徐州市立医院神经内科收治的1 例KD 合并SNMG 患者的临床资料，总结KD 合并SNMG 的临床诊断特征，并复习文献。

结果

患者男性，52 岁，间断性四肢无力2 年，症状呈慢性、进行性、波动性，由近端逐渐进展至远端，晨轻暮重，起病时即伴有肌肉痉挛，以双上肢为主，上肢平举时震颤明显。查体可见轻度男性乳腺发育，口周肌肉萎缩，舌肌纤颤，双手掌大鱼际肌萎缩，双上肢三角肌萎缩，双下肢纤细，双侧肢体肌力4 级，双上肢平举时可见姿势性震颤。血清肌酸激酶水平升高；肌电图提示慢性神经源性损害，脊髓前角细胞受损，累及上下肢肌肉、腹直肌及斜方肌；新斯的明试验阳性；雄激素受体基因的第1 外显子区域CAG 序列重复数目异常扩增；重症肌无力5 项抗体均阴性。考虑患者KD 合并SNMG。给予胆碱酯酶抑制剂溴吡斯的明、辅酶Q₁₀ 治疗，患者症状明显缓解。

结论

KD 合并SNMG 早期误诊率极高，需要临床医生更多地关注肌肉疲劳也可作为KD 的首发症状；基因检测对KD 诊断具有重要意义。

Objective

To investigate the clinical diagnostic features of a case of Kennedy disease（KD） with serum antibody-negative myasthenia gravis （SNMG）.

Methods

The clinical data of a patient with KD combined with SNMG admitted to the Department of Neurology，Xuzhou Municipal Hospital Affiliated to Xuzhou Medical University on June 25，2024 was retrospectively analyzed.The clinical diagnostic characteristics of KD with SNMG were summarized，and the literature was reviewed.

Results

The patient was male，52 years old，and had intermittent limb weakness for 2 years.The symptoms were chronic，progressive and fluctuating，gradually progressing from the proximal end to the distal end，with mild symptoms in the morning and severe symptoms in the evening，accompanied by muscle spasm at the onset of the disease，and tremor was obvious when the upper limbs were raised horizontally.Physical examination showed mild development of the male breast，perioral muscle atrophy，tongue muscle fibrillation，double palmar thenar muscle atrophy，double upper limb deltoid muscle atrophy，double lower limb slender，bilateral limb muscle strength grade 4，postural tremor when both upper limbs were raised horizontally.Serum creatine kinase increased.Electromyography indicated chronic neurogenic injury，with damage to the anterior horn cells of the spinal cord，involving the muscles of the upper and lower limbs，the rectus abdominis and the trapezius.Neostigmine test was positive.The number of CAG repeats in exon 1 region of androgen receptor gene was abnormally amplified.All 5 myasthenia gravis antibodies were negative.KD combined with SNMG was considered.Treatment with the cholinesterase inhibitor pyridostigmine bromide and coenzyme Q₁₀ resulted in significant remission of the patient′s symptoms.

Conclusion

The early misdiagnosis rate of KD combined with SNMG is very high，and clinicians should pay more attention to muscle fatigue as the first symptom of KD.Gene detection is important for the diagnosis of KD.