Excitability properties of human median axons measured at the motor point
Excitability properties of human median axons measured at the motor point
复制标题
在运动点测量的人类中位轴突的兴奋性特性
作者：
S. Kuwabara;H. Bostock;K. Ogawara;J. Sung;S. Misawa;Yukiko Kitano;K. Mizobuchi;C. Lin;T. Hattori
阈值跟踪用于测量短拇外展肌运动点的兴奋性指数（强度-持续时间特性、阈值电张力和电流-阈值关系），并将结果与手腕正中神经的结果进行比较。使用放置在拇指尖的加速度计，运动相关电位被记录为目标反应。当在同一部位刺激时，当目标反应是运动而不是肌肉动作电位时，兴奋性测量结果没有不同，其变异性也没有更大。与腕部刺激相比，运动点刺激显著缩短了强度-持续时间常数和提高了流变酶。此外，潜在加法技术显示，运动点的慢速分量比手腕处的慢速分量小得多。在阈值电张力中，运动点对去极化和超极化调节电流的阈值变化明显小于手腕。强度-持续时间常数和潜加法的差异表明，静息电位下的持续Na+电流在运动点处较小。阈值电张力的差异可能部分取决于纤维几何形状的改变，但表明向内和可能向外的整流在远端增加。运动点兴奋性测试可以为各种周围神经病变和运动神经元疾病的神经末梢病理生理学提供新的见解。中国机械工程学报（英文版），2004
Threshold tracking was used to measure excitability indices (strength–duration properties, threshold electrotonus, and the current‐threshold relationship) at the motor point of the abductor pollicis brevis, and the results were compared with those of the median nerve at the wrist. Using an accelerometer placed at the thumb tip, movement‐related potentials were recorded as target responses. When stimulating at the same site, excitability measurements were no different, and their variability no greater, when the target responses were movements rather than muscle action potentials. Motor point stimulation resulted in significantly shorter strength–duration time‐constant and higher rheobase than wrist stimulation. In addition, the technique of latent addition showed that a slow component was much smaller at the motor point than at the wrist. In threshold electrotonus, threshold changes in response to depolarizing and hyperpolarizing conditioning currents were significantly smaller at the motor point than at the wrist. The differences in strength–duration time‐constant and latent addition suggest that persistent Na+ current at the resting potential is smaller at the motor point. The differences in threshold electrotonus may depend in part on altered fiber geometry but suggest that inward and possibly outward rectification are increased distally. Motor point excitability testing may provide new insights into the pathophysiology of the nerve terminals in a variety of peripheral neuropathies and motor neuron disorders. Muscle Nerve 29: 227–233, 2004
影响因子：
5.5
作者：
LINDGREN, CA;MOORE, JW
通讯作者：
MOORE, JW