亚急性运动神经元病

Subacute Motor Neuronopathy

目的报告1例亚急性运动神经元病的临床、肌肉病理和临床随访结果,讨论其诊断。方法对1例亚急性运动神经元病进行临床资料收集、肌电图检测和活检肌肉的组织学、组织化学病理检查,并进行临床随访。结果患者16岁时诊断患急性淋巴细胞白血病(L1型),经化疗后一直处缓解期。18岁开始双下肢肌无力、肌萎缩,两上肢正常,病程呈亚急性。血清肌酸激酶轻度升高。肌电图显示广泛神经源性受损,神经传导速度正常。肌肉病理显示典型的神经源性肌萎缩,大量靶纤维和肌纤维群组化存在。两次皮质激素治疗均有明显效果,停药后症状加重。1年后患者死于白血病复发。1年临床随访期间,患者两下肢肌无力、肌萎缩无明显恶化,两上肢仍大致正常。结论亚急性运动神经元病是一种罕见的副肿瘤综合征类型。由于发病在肿瘤缓解期,且肌无力、肌萎缩相对稳定,因此易误诊。确诊依靠临床结合肌肉病理检查,并需临床随访。

Objective To report the clinical and myopathologicl features and the course of following-up of a patient with subacute motor neuronopathy （SMN）. Methods The clinical data of the case were collected and EMG was performed. A muscle biopsy was done with histologyical and histochemical staining and the course of following-up was investigated. Results At age of 16 years, the patient was diagnosed for acute lymphoblastic leukemia （type L1）. After chemotherapy, he was of the peried of complete remission all along. The onset of SMN was at 18 years old, the clinical findings were characterized by lower limbs muscles weakness and amyotrophy, but upper limbs were normal . The clinical course was subacute. The level of serum creatine kinase was slightly elevated. EMG presented neurogenic features widely, nerve conduction velocities were normal. Myopatholoical changes showed typical neurogenic atrophy, many target fibers and fiber type grouping were presented. He had dramatic responses to corticosteroid therapy twice and symptoms developed after withdrawal of medication. After 1 year, the patient died of the relapse of leukemia. Within the follow-up period of 1 year, lower limbs muscles weakness and amyotrophy were not obviously progressive, upper limbs were roughly normal still. Conclusion SMN is a rare type of paraneoplastic synodrome. As the onset was in the period of remission of tumour and muscles weakness and amyotrophy remains relatively stable, it is often misdiagnosed. The definite diagnosis of SMN depends on combining clinical data with muscle biopsy, and the course of following-up needs to be investigated.