Paired corticospinal-motoneuronal stimulation increases maximal voluntary activation of human adductor pollicis
Paired corticospinal-motoneuronal stimulation increases maximal voluntary activation of human adductor pollicis
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DOI：
10.1152/jn.00919.2016
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发表时间：
2018-01-01
影响因子：
2.5
通讯作者：
Taylor, Janet L.
中科院分区：
文献类型：
--
作者：
D'Amico, Jessica M.;Donges, Siobhan C.;Taylor, Janet L.
配对皮质脊髓-运动神经元刺激（PCMS）是一种重复的双经颅磁刺激（TMS）和最大运动神经刺激，可以改变皮质脊髓向低阈值运动神经元的传递。为了确定高阈值运动神经元是否会发生类似的变化，我们测试了PCMS是否会影响健康个体的最大自主激活和力。在单独的两天，健康参与者（n = 14）在对照方案（仅TMS）或旨在促进皮质脊髓传递到内收肌政策的PCMS之前和之后进行了短暂的拇指内收最大自愿收缩（MVCs）。不单独进行外周神经刺激。在每一个MVC，一个叠加抽搐被传递到尺神经的最大刺激引起。当肌肉在最大收缩后放松时，类似的刺激会引起静息抽搐。自愿激活计算为（1 =叠加抽搐/静息抽搐）X 100%。尽管两种情况下自愿激活随时间的推移而下降，但PCMS后的下降幅度（-0.4 +/- 4.1%）小于对照方案后的下降幅度（-4.9 +/- 4.9%;P = 0.007）。PCMS后肌电反应比对照组增加（7 +/- 13% vs -3 +/- 10%; P = 0.043）。然而，最大力不受影响。研究结果表明，PCMS对最大内收肌的神经驱动有一定的影响，这表明PCMS可以影响皮质脊髓向高阈值运动神经元的传递。配对皮质脊髓-运动神经元刺激（PCMS）诱导人类脊髓的变化。迄今为止，报道的PCMS的影响仅限于健康和脊髓损伤个体的低阈值运动神经元和低力任务。我们首次表明，这些可塑性变化并不局限于低阈值运动神经元，而是发生在整个运动神经元池中，正如内收肌最大自愿收缩期间随意激活和肌肉活动的增加所证明的那样。
Paired corticospinal-motoneuronal stimulation (PCMS), which delivers repeated pairs of transcranial magnetic stimuli (TMS) and maximal motor nerve stimuli, can alter corticospinal transmission to low-threshold motoneurons in the human spinal cord. To determine whether similar changes occur for high-threshold motoneurons, we tested whether maximal voluntary activation and force can be affected by PCMS in healthy individuals. On 2 separate days, healthy participants (n = 14) performed brief thumb adduction maximal voluntary contractions (MVCs) before and after a control protocol (TMS only) or PCMS designed to facilitate corticospinal transmission to adductor pollicis. Peripheral nerve stimulation alone was not performed. During each MVC, a superimposed twitch was elicited by a supramaximal stimulus delivered to the ulnar nerve. With muscles relaxed following the maximal contraction, a similar stimulus elicited a resting twitch. Voluntary activation was calculated as (1 = superimposed twitch/resting twitch) X 100%. Although voluntary activation decreased over time in both conditions, the decrease was less after PCMS (-0.4 +/- 4.1%) than after the control protocol (-4.9 +/- 4.9%; P = 0.007). This was supported by a greater increase in electromyographic response after PCMS than control (7 +/- 13% vs. -3 +/- 10%; P = 0.043). However, maximal force was not affected. The findings indicate a modest effect of PCMS on maximal neural drive to adductor pollicis, suggesting that PCMS can affect corticospinal transmission to high-threshold motoneurons.NEW & NOTEWORTHY Paired corticospinal-motoneuronal stimulation (PCMS) induces changes in the human spinal cord. To date, the reported effects of PCMS have been limited to low-threshold motoneurons and low-force tasks in healthy and spinal cord injured individuals. For the first time, we show that these plastic changes are not limited to lower threshold motoneurons, but occur across the entire motoneuron pool as demonstrated by the increases in voluntary activation and muscle activity during maximal voluntary contractions of adductor pollicis.