多发性硬化中的周围神经异常

　　摘要：目的　探讨多发性硬化合并周围神经损害的临床特点和发病机制。方法　对2例多发性硬化患者进行临床观察及电生理检查，并作文献复习。结果　2例患者均有下运动神经元异常表现，膝、跟腱反射消失，神经传导速度减慢，电生理检查提示病变既没有损害前角细胞，也没有累及周围神经的髓内根，可能是周围神经受影响。结论　中枢神经系统和周围神经系统联合受累的机制可能在于自身免疫反应，有一种类似髓鞘碱性蛋白的抗原，由于它在中枢神经系统占优势，免疫反应造成神经系统受损程度不同，或者中枢神经系统损害严重，导致血脑屏障及血神经屏障受损，最后导致周围神经脱髓鞘和轴索变性。

　　　　ABSTRACT：Objective　To study the clinical characteristies and mechanisms of peripheral neuropathy in multiple sclerosis.Methods　It was to observe clinical signs and electrophysiologic testing of two patients with multiple sclerosis and combined with reviewing the literature.Results　The two patients with multiple sclerosis showed signs of lower motor neuron abnormalities, The knee and ankle muscle stretch reflexes of the two instance are lost, and peripheral never conduction was slowed. The electrodiagnostic and multiple sclerosis at autopsy indicated that lessions were involving neither the anterior horn nor entirely ventral exit Zones peripheries, It mighr affect the peripheral nerves, As if multiple sclerosis Combined with acute inflammatory demylinating polyradiculoneuropathies.Conclusion　The possibility of the mechanisms that assosiated central nervous system with peripheral nervous system involved were autoimmunity. There might be an antigen such as mylin basic protein. was predominant over central nervous system, So central nervous system and peripheral nervous system were involved differently, and central nervous system was damaged severely, It induced the lesion of the blood-brain and blood-nerve barriers. Finally peripheral nerve demylination and axonal degeneration had occured.

　　Key words：multiple sclerosis; demyelinating disease

　　经典的多发性硬化被描述为中枢神经系统脑白质的脱髓鞘改变，很少累及周围神经系统。本文报告2例合并周围神经损害的多发性硬化。

　　1　临床资料

　　例1：　患者，女性，25岁。主因胸部束带感1个月，双下肢无力，感觉障碍，尿潴留半个月入院。既往于5年前曾有同样病史，当时作胸椎MRI揭示T4髓内脱髓鞘改变，曾住院治疗。入院时体征：左下肢肌力V－级，右下肢肌力Ⅳ级，双膝腱反射亢进，右侧巴彬斯基征阳性，出院时双下肢感觉减退，双下肢肌力Ⅴ级，膝、跟腱反射正常，病理征未引出。此次住院查体： 双眼右视时有不持续眼震，双下肢肌力0级，肌张力降低，膝、跟腱反射消失。双侧巴彬斯基征阳性，T4以下深浅感觉消失。肌电图示所检肌肉运动单位时限、波幅大致均在正常范围，未见病理性自发电位。神经电检查所见：右正中神经、左腓神经、左胫神经运动传导速度轻度减慢、左正中神经感觉传导速度减慢，提示神经原性损害，轻度节段性脱髓鞘样改变。

　　例2：　患者，女性，28岁，干部。主因反复发作双下肢无力3年，加重半年，视物模糊1个月入院。3年内3次(分别于3年前、2年前、半年前)症状反复缓解复发，2年前作头颅及胸椎MRI示右额皮质下及T1-5脊髓长T2异常信号。此次住院查体：眼底双视乳头苍白，左视乳头边界不清，左眼失明，右眼视力可辨认指数(20cm)，左面部痛觉稍减退，舌不能伸出，双上肢肌力Ⅴ级，双下肢肌力0级，双下肢肌张力减弱，膝、跟腱反射消失，双下肢肌肉均匀一致萎缩，双侧霍夫曼征阳性，T2-L1深浅感觉减退，L1以下深感觉丧失，腹壁反射消失，巴彬斯基征(-)。肌电图示，所检肌肉未见病理性自发电位，右股四头肌运动单位时限延长，数量减少。神经电检查示，双腓神经及右胫神经运动传导速度均减慢，运动单位总电压均明显降低，右胫神经显示失神经传导，右腓肠神经感觉传导速度减慢。提示神经原性损害，双下肢轴索变性为主伴节段性脱髓鞘。