The recruitment order of electrically activated motor neurons investigated with a novel collision technique
The recruitment order of electrically activated motor neurons investigated with a novel collision technique
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DOI：
10.1016/j.clinph.2006.10.017
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发表时间：
2007-02-01
影响因子：
4.7
通讯作者：
Farina, Dario
中科院分区：
文献类型：
--
作者：
Hennings, Kristian;Kamavuako, Ernest Nlandu;Farina, Dario
目的：开发一种新的碰撞技术来评估电激活神经纤维的激活顺序，这是功能电疗或运动单位数估计结果解释的重要问题。方法：利用指外展肌腹腱结构记录复合肌动作电位。在10名健康男性受试者上应用了一种新颖的改进Hopf碰撞技术，以确定所有尺神经纤维和被电刺激激活的纤维的传导速度（DCV）的分布，这些电刺激引起20%、50%和80%的最大肌肉反应。结果：最大神经传导速度（mean SE）为64.1±0.85 m/s。估计DCV的传导速度中位数分别为58.9 +/- 0.97 m/s（刺激20%）、58.0 +/- 0.98 m/s（50%）、57.2 +/- 0.91 m/s（80%）和56.5 +/- 0.84 m/s（全神经），差异均有统计学意义，P < 0.001)。结论：所提出的碰撞技术可以评估最大和次最大刺激水平下的神经传导速度分布，并为电刺激下神经纤维的反向激活顺序提供证据。意义：神经电刺激引起的过度疲劳可以解释为大直径神经纤维优先激活。首先通过电刺激激活的运动单元可能不能代表肌肉中的运动单元池，这限制了一些提出的运动单元计数方法的可靠性。(c) 2006年国际临床神经生理学联合会。爱思唯尔爱尔兰有限公司出版。版权所有。
Objective: The development of a novel collision technique for assessment of the activation order of electrically activated nerve fibers, which is an important question in functional electrical therapy or for interpretation of results of motor unit number estimates.Methods: Compound muscle action potentials were recorded with the belly-tendon configuration from the abductor digiti minimi. A novel modified Hopf's collision technique was applied on ten healthy male subjects to determine the distributions of conduction velocities (DCV) of all ulnar nerve fibers and of the fibers activated by electrical stimuli eliciting 20%, 50%, and 80% of the maximal muscle response.Results: The maximum nerve conduction velocity was (means SE) 64.1 +/- 0.85 m/s. The median conduction velocity of estimated DCV was 58.9 +/- 0.97 m/s (stimulus at 20%), 58.0 +/- 0.98 m/s (50%), 57.2 +/- 0.91 m/s (80%), and 56.5 +/- 0.84 m/s (whole nerve) (all different between each other, P < 0.001).Conclusions: The proposed collision technique allows the assessment of nerve conduction velocity distributions at maximal and sub-maximal stimulation levels and provided evidence for an inverse activation order of nerve fibers with electrical stimulation.Significance: The excessive fatigue seen with nerve electrical stimulation can be explained by a preferential activation of large diameter nerve fibers. The motor units first activated with electrical stimulation are likely not representative of the motor unit pool in the muscle, which poses limitations in the reliability of some of the proposed methods for motor unit counting. (c) 2006 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.