Dancey Erin, Murphy Bernadette, Srbely John, Yielder Paul
Faculty of Health Sciences, University of Ontario Institute of Technology, 2000 Simcoe Street North, Oshawa, ON, L1H 7K4, Canada.
Exp Brain Res. 2014 Sep;232(9):2879-89. doi: 10.1007/s00221-014-3966-1. Epub 2014 May 13.
Experimental pain is known to affect neuroplasticity of the motor cortex as well as motor performance, but less is known about neuroplasticity of somatosensory processing in the presence of pain. Early somatosensory evoked potentials (SEPs) provide a mechanism for investigating alterations in sensory processing and sensorimotor integration (SMI). The overall aim of this study was to investigate the interactive effects of acute pain, motor training, and sensorimotor processing. Two groups of twelve participants (N = 24) were randomly assigned to either an intervention (capsaicin cream) or placebo (inert lotion) group. SEP amplitudes were collected by stimulation of the median nerve at baseline, post-application and post-motor training. Participants performed a motor sequence task while reaction time and accuracy data were recorded. The amplitude of the P22-N24 complex was significantly increased following motor training for both groups F(2,23) = 3.533, p < 0.05, while Friedman's test for the P22-N30 complex showed a significant increase in the intervention group [χ(2) (df = 2, p = 0.016) = 8.2], with no significant change in the placebo group. Following motor training, reaction time was significantly decreased for both groups F(1,23) = 59.575, p < 0.01 and overall accuracy differed by group [χ(2) (df = 3, p < 0.001) = 19.86], with post hoc testing indicating that the intervention group improved in accuracy following motor training [χ(2) (df = 1, p = 0.001) = 11.77] while the placebo group had worse accuracy [χ(2) (df = 1, p = 0.006) = 7.67]. The improved performance in the presence of capsaicin provides support for the enhancement of knowledge acquisition with the presence of nontarget stimuli. In addition, the increase in SEP peak amplitudes suggests that early SEP changes are markers of SMI changes accompanying motor training and acute pain.
已知实验性疼痛会影响运动皮层的神经可塑性以及运动表现，但对于疼痛存在时体感加工的神经可塑性了解较少。早期体感诱发电位（SEP）为研究感觉加工和感觉运动整合（SMI）的改变提供了一种机制。本研究的总体目的是调查急性疼痛、运动训练和感觉运动加工的交互作用。两组各12名参与者（N = 24）被随机分配到干预组（辣椒素乳膏）或安慰剂组（惰性洗剂）。在基线、涂抹后和运动训练后，通过刺激正中神经收集SEP波幅。参与者执行运动序列任务，同时记录反应时间和准确性数据。两组在运动训练后P22 - N24复合波的波幅均显著增加，F(2,23) = 3.533，p < 0.05，而对P22 - N30复合波进行的弗里德曼检验显示干预组有显著增加[χ(2)（自由度 = 2，p = 0.016）= 8.2]，安慰剂组无显著变化。运动训练后，两组的反应时间均显著缩短，F(1,23) = 59.575，p < 0.01，且总体准确性存在组间差异[χ(2)（自由度 = 3，p < 0.001）= 19.86]，事后检验表明干预组在运动训练后准确性提高[χ(2)（自由度 = 1，p = 0.001）= 11.77]，而安慰剂组准确性更差[χ(2)（自由度 =
