Department of Neuroscience, Uppsala University, Uppsala, Sweden.
J Pain Res. 2013 Jun 24;6:479-86. doi: 10.2147/JPR.S44648. Print 2013.
Electric motor cortex stimulation has been reported to be effective for many cases of neuropathic pain, in the form of epidural stimulation or transcranial direct current stimulation (tDCS). A novel technique is transcranial random noise stimulation (tRNS), which increases the cortical excitability irrespective of the orientation of the current. The aim of this study was to investigate the effect of tRNS on neuropathic pain in a small number of subjects, and in a case study explore the effects of different stimulation parameters and the long-term stability of treatment effects.
THE STUDY WAS DIVIDED INTO THREE PHASES: (1) a double-blind crossover study, with four subjects; (2) a double-blind extended case study with one responder; and (3) open continued treatment. The motor cortex stimulation consisted of alternating current random noise (100-600 Hz), varying from 0.5 to 10 minutes and from 50 to 1500 μA, at intervals ranging from daily to fortnightly.
One out of four participants showed a strong positive effect (also compared with direct-current-sham, P = 0.006). Unexpectedly, this effect was shown to occur also for very weak (100 μA, P = 0.048) and brief (0.5 minutes, P = 0.028) stimulation. The effect was largest during the first month, but remained at a highly motivating level for the patient after 6 months.
The study suggests that tRNS may be an effective treatment for some cases of neuropathic pain. An important result was the indication that even low levels of stimulation may have substantial effects.
电刺激运动皮层已被报道对多种神经性疼痛有效，形式包括硬膜外刺激或经颅直流电刺激（tDCS）。一种新的技术是经颅随机噪声刺激（tRNS），它可以增加皮质兴奋性，而与电流方向无关。本研究的目的是在少数受试者中研究 tRNS 对神经性疼痛的影响，并通过病例研究探索不同刺激参数的效果和治疗效果的长期稳定性。
该研究分为三个阶段：（1）四例患者的双盲交叉研究；（2）一例应答者的双盲扩展病例研究；（3）开放继续治疗。运动皮层刺激由 100-600Hz 的交流电随机噪声组成，持续时间从 0.5 分钟到 10 分钟，电流强度从 50μA 到 1500μA，间隔从每日到每两周不等。
四名参与者中有一名表现出强烈的积极效果（与直流电假刺激相比，P=0.006）。出乎意料的是，这种效果也出现在非常弱（100μA，P=0.048）和短暂（0.5 分钟，P=0.028）的刺激中。效果在第一个月最大，但在 6 个月后对患者仍保持在高度激励的水平。
该研究表明，tRNS 可能是治疗某些神经性疼痛的有效方法。一个重要的结果是表明即使是低水平的刺激也可能有显著的效果。
