Department of Neurology, University of Munich, Munich, Germany.
Clin Neurophysiol. 2010 Jun;121(6):957-61. doi: 10.1016/j.clinph.2010.01.014. Epub 2010 Feb 11.
Transcranial direct current stimulation induces long-lasting changes in cortical excitability in humans depending on the current used. Further, transcutaneous spinal application of direct current (tsDCS) induces plastic changes in spinal conduction properties, tested by somatosensory evoked potentials. To verify this thesis on plastic changes in spinal circuitry, we investigated the effects of tsDCS on H-reflex size and post-activation depression.
Ten healthy subjects participated in the study. The H(max)/M(max) ratio and H-reflex post-activation depression were evaluated before, at current offset, and 15 min after anodal, cathodal or sham tsDCS. Stimulation of the spinal cord (2.5 mA, 0.063 mA/cm(2), 0.056 C/cm(2)) was applied for 15 min at Th11 level.
Anodal tsDCS induced a lasting decrease in H-reflex post-activation depression, while cathodal stimulation resulted in a sustained increase. Sham stimulation had no significant effects. The H(max)/M(max) ratio remained unchanged throughout all conditions.
Anodal and cathodal tsDCS is a non-invasive and painless method that is able to induce lasting changes in the efficacy of the Ia fibre-motoneurone synapse.
Transcutaneous spinal DC stimulation might be a valuable new tool in modulating spinal motor pathways.
经颅直流电刺激可根据所使用的电流在人体中诱导皮质兴奋性的持久变化。此外，经皮脊髓直流电刺激（tsDCS）可通过体感诱发电位测试诱导脊髓传导特性的塑性变化。为了验证脊髓回路可塑性变化的这一理论，我们研究了 tsDCS 对 H 反射大小和后激活抑制的影响。
10 名健康受试者参与了这项研究。在阳极、阴极或假 tsDCS 之前、电流截止时和 15 分钟后，评估 H(max)/M(max)比值和 H 反射后激活抑制。在 Th11 水平应用脊髓刺激（2.5 mA、0.063 mA/cm(2)、0.056 C/cm(2))，持续 15 分钟。
阳极 tsDCS 诱导 H 反射后激活抑制持续降低，而阴极刺激导致持续增加。假刺激没有显著影响。在所有条件下，H(max)/M(max)比值保持不变。
阳极和阴极 tsDCS 是一种非侵入性和无痛的方法，能够诱导 Ia 纤维-运动神经元突触效能的持久变化。
经皮脊髓直流电刺激可能是调节脊髓运动通路的一种有价值的新工具。
