Kobuch Sophie, Henderson Luke A, Macefield Vaughan G, Brown R
School of Medicine, Western Sydney University, Locked Bag 1797, Penrith, NSW, 2751, Australia.
Department of Anatomy and Histology, University of Sydney, Sydney, Australia.
Exp Brain Res. 2018 Jul;236(7):1919-1925. doi: 10.1007/s00221-018-5271-x. Epub 2018 Apr 25.
Pain elicited by intramuscular infusion of hypertonic saline solution causes muscle sympathetic nerve activity (MSNA) to increase in some subjects, yet decrease in others. Although the direction of the response is not predictable based on baseline physiological and psychological parameters, we know that it results from sustained functional changes in specific brain regions that are responsible for the behavioral and cardiovascular responses to psychological stressors, as well as those involved in attention. The aim of this study was to investigate whether MSNA responses to experimental muscle pain in humans could be altered with an audiovisual stimulus that served to distract them from the pain. MSNA was recorded from the left common peroneal nerve of 20 young healthy individuals during a 45-min intramuscular infusion of hypertonic saline solution into the ipsilateral tibialis anterior muscle. The distracting stimulus commenced 15 min after the start of the infusion and lasted for 15 min. Fifteen subjects showed an increase in mean burst amplitude of MSNA (to 176.4 ± 7.9% of baseline), while five showed a decrease (to 73.1 ± 5.2% of baseline); distraction had no effect on these profiles. These results indicate that even though the subjects were attending to the audiovisual stimulus, and were presumably distracted from the pain, it failed to alter the MSNA responses to muscle pain.
肌肉内输注高渗盐溶液引发的疼痛会使一些受试者的肌肉交感神经活动（MSNA）增加，而另一些受试者的MSNA则会减少。尽管根据基线生理和心理参数无法预测反应的方向，但我们知道这是由特定脑区持续的功能变化导致的，这些脑区负责对心理应激源的行为和心血管反应，以及与注意力有关的反应。本研究的目的是调查人类对实验性肌肉疼痛的MSNA反应是否可以通过视听刺激来改变，这种刺激可使他们分散对疼痛的注意力。在向20名年轻健康个体的同侧胫骨前肌进行45分钟的肌肉内高渗盐溶液输注期间，从左侧腓总神经记录MSNA。分心刺激在输注开始15分钟后开始，持续15分钟。15名受试者的MSNA平均爆发幅度增加（达到基线的176.4±7.9%），而5名受试者的MSNA平均爆发幅度减少（降至基线的73.1±5.2%）；分心对这些情况没有影响。这些结果表明，尽管受试者关注视听刺激，并且可能分散了对疼痛的注意力，但它未能改变对肌肉疼痛的MSNA反应。
