多灶性运动神经病1例

Case Report of Multifocal Motor Neuropathy

目的探讨儿童多灶性运动神经病(MMN)的特点及临床与电生理诊断标准。方法对1例临床表现为慢性进行性、非对称性肢体无力的MMN患儿进行临床、肌电图神经传导检查及腓肠神经活检。结果该MMN患儿为8岁男童,临床主要表现为慢性非对称性、进行性肢体无力3a,以右上肢为重,受累肢体肌肉萎缩,肌容积减少,上肢重于下肢,远端重于近端,感觉检查未见异常。右尺神经和右胫神经复合肌肉动作电位负波面积近端较远端均减少50%以上,2条神经出现波形离散,提示运动神经传导阻滞。腓肠神经活检未见特征性病理改变,患儿经用大剂量IVIG治疗后右手力量增加,遗留有明显的肌肉萎缩和轻度握力减弱,但无明显感觉减退。结论 MMN虽多见于成人,但亦可在儿童起病,神经传导检查存在运动神经传导阻滞是确诊的重要依据,本病需与慢性炎症性脱髓鞘性多神经病、Lewis-Sumner综合征及轴索型MMN等鉴别,治疗上首选大剂量IVIG。

Objective To explore the clinical,electropnysiological characteristics and diagnosis criteria of multifocal motor neuropathy（MMN）in children.Methods One child with MMN was examined by clinical doctors and underwent electromyography,nerve conduction stu-dies with a standard method followed by a detailed analysis of compound muscle potentials（CMAP）.Sural nerve biopsy sample was examined under light and electromicroscopy.Results An 8-year-old boy presented recurrent,progressive,unsymmetrical weakness of limbs for 3 years.His right arm was most severely affected.The affected limbs appeared muscular atrophy and his upper extremities（and distal part）were worse than lower extremities（and proximal part）.No abnormality was found in all sensory nerves.The proximal negative CMAP area reduction than distal negative CMAP area exceeded 50% on lunar and tibial nerves and the other two nerves had temperal dispersion which were consisted with conduction block.His spine cord MRI and sural nerve biopsy were normal.High dose IVIG was given and the weakness was improved,but he remained in mild weakness and atrophy in his right arm.Conclusions MMN is a disease which was usually found in adults but could be found in childhood as well.Nerve conduction block is a key point to find conduction block and make the diagnosis.The differential diagnosis includes chronic inflammatory demyelinating polyradiculoneuropathy,Lewis-Sumner syndrome,axonal MMN.High dose IVIG is the first choice of treatment in MMN.