中文摘要：

目的探讨以上运动神经元损害为主要表现的肌萎缩侧索硬化（UMN-DALS）的临床和神经电生理特点。方法回顾分析76例UMN-DALS患者及19例原发性侧索硬化（PLS）患者，对其临床表现和神经电生理特点进行总结、比较。神经电生理研究主要包括四肢神经传导速度和延髓、颈、胸、腰骶4个区的肌肉肌电图检测，每隔6个月复查1次。结果8例初诊为PLS的患者随访中出现下运动神经元损害的表现，转入UMN—DALS组，此组患者增为84例。〉40岁的UMN-DALS患者中女性更多（男：女=1：1．37）。32例（38．1％）延髓部起病，从首发症状到肌电图提示神经源性改变平均为30个月，77例（91．6％）在病程4年内出现下运动神经元损害的表现。随访4年时，UMN-DALS组修改版ALS神经功能评分（分）由40±3下降为32±4（t=1．83，P〈0．05）；UMN—DALS组与PLS组第一骨间肌运动单位动作电位波幅、时限相比[（1003．7±25．2）μV和（353．5±21．5）txV，t=2．34，P〈0．05；（19．8±2．3）ms和（9．6±1．3）ms，t=1．85，P〈0．05]差异有统计学意义。结论UMN．DALS患者中女性、以延髓部起病患者比例较高，比PLS进展快，肌电图神经源性损害局限。

英文摘要：

Objective To investigate the clinical and electrophysiological characteristics of upper motor neuron-dominant amyotrophic lateral sclerosis （UMN-D ALS ）. Methods The clinical and electrophysiological characteristics were analyzed retrospectively in 76 patients with UMN-D ALS and 19 patients with primary lateral sclerosis （PLS）. Electrophysiological study included the examination of median nerve, ulnar nerve, tihial nerve, peroneal nerve and sural nerve except for the electromyogram of bulbar region, cervical region, thoracic region and lumbosacral region. Results The diagnosis in 8 PLS patients were changed to UMN-D ALS after detailed review. In UMN-D ALS patients, there were more females in age group of older than 40 （ male ： female = 1 ： 1.37 ） and 32 patients （ 38. 1% ） had onset with hulbar dysfunction. UMN-D ALS patients showed electromyograph evidence of denervation at 30 months （median） after onset, and clinical lower motor neuron （LMN） signs 6 months later. Seventy-seven patients （91.6%） developed LMN sign by 4 years from symptom onset. ALS functional rating score-revised changed from 40 ± 3 to 32 ±4 in 4 years in UMN-D ALS patients （t = 1.83,P 〈 0. 05 ）. The amplitude of motor unit action potential （MUAP） on the first interosseus dorsalis was higher （（ 1003.7 ± 25.2 ） μV vs （353.5 ± 21.5） μV, t=2.34, P〈0.05） and the duration of MUAP was longer （（19.8 ±2.3） ms vs （9.6 ± 1.3 ） ms, t = 1.85, P 〈 0. 05） in UMN-D ALS patients than in PLS patients. Conclusions UMN-D ALS occurs more in female cases, with more bulbar onset and with faster progression than PLS does. It also presents focal denervation in electromyograph.