同心轴针极肌电图运动单位电位多项参数定量分析

A quantitative analysis of motor unit potential multi-parameters in concentric needle electromyography

目的研究运动单位电位（ＭＵＰ）多项参数的特征、相互关系、正常值及其神经生理意义。方法１１６名健康成人和４５例神经原性疾病患者的拇短展肌、胫前肌和股四头肌的２６５８个ＭＵＰ，通过棘波触发平均技术得到记录。对ＭＵＰ大小指数（ＳＩ）等９项参数及其９５％或９９％可信限区间进行ＭＵＰ水平统计和显著性检验。结果在相互独立的参数中，以时限和波幅的相关性最为明显，这２种参数从不同角度反映了ＭＵＰ的特征。面积与波幅比值和波幅为相互独立的参数。在ＭＵＰ所有的参数中，以波幅／面积和波幅／ＳＩ比值的相关性最为明显，面积和ＳＩ同为波幅依赖性参数。经９５％或９９％可信限显著性检验证明，面积、ＳＩ、波幅和时限具有较其他参数更高的诊断敏感性。结论ＭＵＰ时限低于面积、ＳＩ的诊断作用，仍为一项重要参数。此种结果与传统肌电图和新近模式匹配肌电图均有所不同。

Objective To study the characteristics and the clinical significance of different parameters of the motor unit potentials (MUP) in spike-triggered averaging electromyography (EMG). Method From the vastus medialis, tibialis anterior and abductor pollicis brevis muscles 1903 MUP in 116 healthy adults (ranging from 17 to 72 years old) and 755 MUP in 45 neurogenic patients were registered with concentric needle electrodes. The normal values and the 95% or 99% confidence limits of the 9 parameters were calculated at the MUP level. Results In the independent parameters of the MUP, a fairly strong correlation (r=0.284～0.342) existed between the duration and the amplitude, which suggested that a common feature of the MUP could be reflected from the different points of view by these two parameters. Among all the parameters, the most significant correlation existed between the area and the amplitude (r=0.779, 0.786, 0.789) and between the size index and the amplitude (r=0.832, 0.864, 0.997), which indicated that both the area and the size index were amplitude dependent parameters. The area/amplitude ratio had a rather strong correlation with the duration, but they were different parameters. The standard deviations of the duration were smaller than those recorded with the template matching technique, which could offer a better diagnostic yield in neurogenic MUP. The area, the size index as well as the amplitude and the duration were considered to be the most important parameters at the 95% or 99% confidence level of significance analysis between normal and neurogenic MUP. Conclusion The findings were different from not only those of the conventional EMG but also those of the template matching EMG.