三重磁刺激技术对上运动神经元损伤的评价作用

Evaluation of the upper motor neuron lesions in motor neuron disorders with the triple stimulation technique

目的研究三重磁刺激技术(TST)的特点,探讨TST在评价运动神经元疾病患者上运动神经元(UMN)损害中的作用。方法选取肌萎缩侧索硬化(ALS)患者12例、下运动神经元综合征(LMNS)患者14例,分别进行双上肢小指展肌TST测定及运动诱发电位(MEP)潜伏期、中枢运动传导时间(CMCT)测定,并将TST波幅比与改良的医学研究委员会(MRC)评分、修订的肌萎缩侧索硬化功能评分量表(ALSFRS-R)评分、肺功能百分比、病程等进行相关性分析。结果 ALS患者12例均完成双侧TST检测,其尺神经TST波幅比为(55.8±32.6)%,较正常参考值下降(F=-3.448,P=0.002),TST波幅比阳性率为70.8%。LMNS患者共13例完成TST检测,其尺神经TST波幅比为(79.4±16.4)%,与正常参考值无统计学差异(F=0.215,P=0.832)。ALS组尺神经TST波幅比〔(55.8±32.6)%〕低于LMNS〔(79.4±16.4)%〕(F=-3.275,P=0.002)。TST波幅比评价UMN体征的敏感度76.5%,高于传统电生理指标;特异度为54.5%,低于传统电生理指标。TST波幅比与改良的MRC评分存在相关性(r=0.431,P=0.035),与ALSFRS-R评分、肺功能、病程、MEP潜伏期以及CMCT均无相关性。结论 TST可以发现亚临床UMN损害,其敏感性高于传统电生理观测指标。TST可以定量评估UMN受损程度,有可能用于ALS患者病情监测。

Objective To quantitatively estimate upper motor neuron （UMN） lesions with the triple stimulation technique （TST） in patients with motor neuron disorder. Methods Twelve amyotrophic lateral sclerosis （ALS） patients and fourteen patients with lower motor neuron syndromes （LMNS） were enrolled in the study. TST of abductor little finger, motor evoked potential （MEP）, central motor conduction time （CMCT） were examined on both sides among the patients respectively. The correlation between TST and modified medical research council （MRC）, score of amyotrophic lateral sclerosis functional rating scale revised （ALSFRS-R）, the percentage of forced vital capacity （FVC%） and duration were analyzed. Results The TST amplitude ratio significantly decreased in ALS patients [（55.8±32.6）%] compared with the controls and patients with LMNS （79. 4±16. 4）%] （F=-3.448, P=0.002; F=-3.275, P=0.002）, the positive ratio was 70.8%. But the values had no significant difference between the patients with LMNS [（79.4±16.4）%] and the controls （F= 0. 215, P=0. 832）. The sensitivity of the TST amplitude ratio （76.5%） in detecting UMN lesions was higher than other TMS parameters, but not the specificity （54.5%）. The TST amplitude ratio was significantly correlated with modified MRC （r=0. 431, P=0. 035）, but had no correlation with the scores of ALSFRS-R, FVC%, duration, MEP latency and CMCT. Conclusions TST appears to be more sensitive and useful in the diagnosis of subclinical UMN involvement in ALS than eonventional TMS technique. TST might quantitatively assess the UMN loss, and be used to monitor the progression of disease.