Department of Neurology, Franz Tappeiner Hospital, Merano, Italy; Department of Neurology, Christian Doppler Medical Center, Paracelsus Medical University, Salzburg, Austria.
Department of Neurorehabilitation, Hospital of Vipiteno, Italy.
Brain Res Bull. 2019 May;148:1-9. doi: 10.1016/j.brainresbull.2019.03.001. Epub 2019 Mar 9.
Several studies have applied transcranial magnetic stimulation (TMS) in the attempt to further explore the pathophysiological mechanisms of phantom-limb pain (PLP) and non-painful phantom sensations (PS). We performed a systematic review of available evidence of this emerging technology in this indication. We identified studies which report a reduced intracortical inhibition and increased intracortical facilitation in the hemisphere contralateral to the PLP. TMS mapping revealed a significant lateralization of the center of gravity and an enlargement of the excitable area on the hemisphere contralateral to the amputation. N-Methyl-d-Aspartate-mediated mechanisms influence the changes of intracortical inhibition and facilitation occurring after limb amputation; however, these cortical excitability changes and PLP are independent of each other. TMS can also influence brain function if applied repetitively. A few studies have begun to therapeutically use repetitive TMS (rTMS) to relief PLP and non-painful PS. rTMS of the contralateral parietal cortex lead to a transient reduction in pain intensity. High frequency rTMS applied over the contralateral motor cortex (M1) or low frequency rTMS over the unaffected hemisphere might also induce significant clinical improvement in PLP. On the other hand, serum beta-endorphin increased significantly after real stimulation over contralateral M1. This systematic review illustrates that TMS technique is an emerging tool to gain insights to pathophysiological aspects of pain and non-painful phantom phenomena. Moreover, TMS could support appropriate patient selection for different therapies and may also have therapeutic utility in subjects with PLP or PS, though the evidence is still very preliminary and well-designed studies in larger cohort of patients are warranted.
几项研究应用经颅磁刺激（TMS）来进一步探索幻肢痛（PLP）和无痛性幻肢感觉（PS）的病理生理机制。我们对该新兴技术在该适应证中的现有证据进行了系统评价。我们确定了报告对侧大脑半球皮质内抑制减少和皮质内易化增加的研究。TMS 映射显示，在截肢对侧半球，重心明显偏侧化，可兴奋区扩大。N-甲基-D-天冬氨酸介导的机制影响肢体截肢后皮质内抑制和易化的变化；然而，这些皮质兴奋性变化与 PLP 是相互独立的。如果重复应用 TMS，也可以影响大脑功能。一些研究已开始将重复经颅磁刺激（rTMS）用于缓解 PLP 和无痛性 PS。对侧顶叶皮质的 rTMS 可导致疼痛强度短暂降低。对侧运动皮质（M1）的高频 rTMS 或未受影响半球的低频 rTMS 也可能导致 PLP 显著临床改善。另一方面，在对侧 M1 进行真实刺激后，血清β-内啡肽显著增加。这项系统评价表明，TMS 技术是一种新兴工具，可以深入了解疼痛和无痛性幻肢现象的病理生理方面。此外，TMS 可能支持对不同治疗方法的适当患者选择，并且对 PLP 或 PS 患者也可能具有治疗作用，尽管证据仍非常初步，需要对更大患者队列进行精心设计的研究。
