中文摘要：

目的：揭示诊断时运动单位估数（motor unit number estimate，MUNE）的线性变化率与生存时间的相关性。方法：收集2002年1月至2005年12月肌萎缩侧索硬化（amyotrophic lateral sclerosis，ALs）患者129例，全部患者记录临床资料、用力肺活量（forced vital capacity，FVC）、电生理指标和神经功能等级评分（ALS functional rating scale，ALSFRS），每3个月对患者进行1次面访或电话随访，直至终点事件（死亡或进行气管切开）。结果：患者的平均发病年龄为（52．19±11．00）岁，中位生存时间为45．71个月（95％的可信区间为35～51个月）。用Kaplan-Meier单因素分析方法，发现MUNE的线性变化率是影响生存时间的重要因素（P〈0．05）。进一步用Cox风险比例模型分析，MUNE的线性变化率为生存时间的重要预后因子（P〈0．01）。用2．9／月作为分界点，诊断时MUNE线性变化率超过此值的生存时间较短，反之较长（P〈0．05），其下降一个单位，死亡风险下降34．2％。结论：基于MUNE的线性估测方法可以从疾病进展的某一点判断病情，从而将患者分层，有力地影响生存时间。MUNE的线性估测值是较年龄、起病部位、确诊时间更为重要的影响生存时间的因素。

英文摘要：

Objective：To identify the correlation between the progression rate of motor unit number estimate （MUNE） at diagnosis and survival. Methods： We included 129 patents with amyotrophic lateral sclerosis （ALS） enrolled in our hospital from January 2002 to December 2005. We recorded clinical features, ALS functional rating scale （ALSFRS）, forced vital capacity （FVC） and electrophysiological data at diagnosis. The patients were monitored every 3 months from visit to death or tracheotomy. Results： Mean age at onset was （52. 19 ± 11.00） years. The median survival time from symptom onset was 45.71 months （95% CI = 35 to 51 ）. In univariate analysis of Kaplan-Meier method, outcome was significantly related to progression rate of MUNE （ P 〈 0. 05 ）. In the Cox multivariate model, progression rate of MUNE was a significant prognostic factor of survival （P 〈 0. 01 ）. Using 2.9/month as cutoff point, the value beyond this point at diagnosis tended to have a shorter survival （ P 〈 0. 05 ）. A 1-unit decrease in the progression rate of MUNE was associated with a 34. 2% decrease risk of death. Conclusion： Progression rate of MUNE at diagnosis can provide the information of disease progression at one particular point, which may help to stratify patients and affect survival. It is the strongest prognostic factor of survival in patients with ALS compared with age, onset site and time from onset to diagnosis.