Institut fur Neuroinformatik, Neural Plasticity Lab, Ruhr-University-Bochum, Germany.
Brain Stimul. 2012 Oct;5(4):647-51. doi: 10.1016/j.brs.2011.07.002. Epub 2011 Aug 16.
Electrical repetitive sensory stimulation (rSS) is a direct and effective means of inducing plasticity processes in human beings, and is increasingly being used as a therapeutic intervention. Suprathreshold intensities induce beneficial effects on tactile perception and sensorimotor abilities. However, it is not known whether there is an optimal range of stimulus intensity.
We investigated the effect of varied intensities (low, 1.19 ± 0.07 mA; intermediate, 3.33 ± 0.27 mA; and high, 4.42 ± 0.56 mA) on the outcome of a 30-minute electrical rSS applied to the index finger (intermittent high-frequency stimulation, 20 Hz and interburst interval, 5 seconds) in three groups (n = 10 each) of participants. As a marker of perceptual changes, we measured tactile spatial two-point discrimination on the stimulated finger and on the heel of the hand before and after the rSS.
rSS improved discrimination performance, with the gain being the highest in the high-intensity group and the lowest in the low-intensity group. Measurements on the heel of the hand revealed small improvements in the high-intensity group, indicative of recruitment processes.
rSS of maximal intensity induced the strongest effects, indicative of a monotonic intensity-gain characteristic with no U-shaped dependency.
电重复感觉刺激（rSS）是诱导人类可塑性过程的一种直接有效的手段，并且越来越多地被用作治疗干预措施。阈上强度可对触觉感知和运动能力产生有益影响。然而，尚不清楚是否存在最佳的刺激强度范围。
我们研究了不同强度（低强度，1.19 ± 0.07 mA；中强度，3.33 ± 0.27 mA；高强度，4.42 ± 0.56 mA）对三组（每组 10 人）参与者的食指接受 30 分钟电 rSS（间歇性高频刺激，20 Hz 和爆发间隔，5 秒）后的结果的影响。作为感知变化的标志物，我们在刺激手指和手部脚跟之前和之后测量了触觉空间两点辨别力。
rSS 改善了辨别性能，高强度组的增益最高，低强度组的增益最低。手部脚跟的测量结果显示高强度组有较小的改善，表明存在募集过程。
最大强度的 rSS 诱导出最强的效果，表明存在单调强度增益特征，不存在 U 形依赖性。
