■神经肌肉电刺激(NMES)可诱导中枢神经系统(CNS)的神经可塑性,并改善CNS病变患者的运动功能。然而,NMES刺激持续时间的延长降低了其临床适用性。经皮脊髓直流电刺激(tsDCS),这增加了传入输入,可以增强效果并减少NMES的刺激持续时间。这项研究调查了运动皮层的兴奋性,体感皮层,NMES和tsDCS联合刺激后的脊髓运动神经元。
■在本研究的55名参与者中,将24个分配给实验1,将15个分配给实验2,将16个分配给实验3。他们在不同的日子接受了20分钟的干预:(1)NMES联合tsDCS(NMES+tsDCS),(2)NMES联合假tsDCS(NMES+假tsDCS),和(3)假NMES联合tsDCS(假NMES+tsDCS)。NMES以25Hz的强度传递到右腓总神经,强度为运动阈值的120%。对于tsDCS,阴极电极位于胸椎第10-12椎骨水平,阳极电极位于右肩。刺激强度为2.5mA。在实验1中,通过经颅磁刺激在刺激后60分钟内测量运动诱发电位(MEP)和短潜伏期内抑制(SICI)。在实验2中通过记录经皮脊髓刺激引起的后根肌反射(PRMR)来评估脊髓运动神经元的兴奋性,在实验3中通过记录体感诱发电位(SEP)来评估初级体感皮层的兴奋性。刺激后15分钟。
■与刺激前相比,NMES+tsDCS显着增加MEP持续60分钟或更长时间,后立即显著降低SICI。相反对比,PRMR立即显著下降,SEP保持不变。
■这些结果表明,来自不同刺激位置的同时传入输入会严重诱导初级运动皮层的可塑性。NMES与tsDCS的联合刺激可能会促进新的神经康复技术的发展。
UNASSIGNED: Neuromuscular electrical stimulation (NMES) induces neural plasticity of the central nervous system (CNS) and improves motor function in patients with CNS lesions. However, the extended stimulus duration of NMES reduces its clinical applicability. Transcutaneous spinal direct current stimulation (tsDCS), which increases afferent input, may enhance the effects and reduce the stimulus duration of NMES. This study investigated the excitability of the motor cortex, somatosensory cortex, and spinal motor neurons after the combined stimulation of NMES and tsDCS.
UNASSIGNED: Among the 55 participants in this study, 24 were allocated to experiment 1, 15 to experiment 2, and 16 to experiment 3. They received intervention for 20 min on different days: (1) NMES combined with tsDCS (NMES + tsDCS), (2) NMES combined with sham tsDCS (NMES + sham tsDCS), and (3) sham NMES combined with tsDCS (sham NMES + tsDCS). NMES was delivered to the right common peroneal nerve at 25 Hz with the intensity at 120% of the motor threshold. For tsDCS, the cathodal electrode was positioned on the thoracic 10th-12th vertebral levels, and the anodal electrode was located on the right shoulder. The stimulus intensity was 2.5 mA. In experiment 1, motor evoked potentials (MEPs) and short-latency intracortical inhibition (SICI) were measured by transcranial magnetic stimulation up to 60 min after stimulation. The spinal motor neurons\' excitability was assessed by recording the posterior root muscle reflex (PRMR) induced via transcutaneous spinal cord stimulation in experiment 2, and the primary somatosensory cortex excitability was evaluated by recording the somatosensory evoked potentials (SEPs) in experiment 3 up to 15 min after stimulation.
UNASSIGNED: Compared to before the stimulation, NMES + tsDCS significantly increased MEP for 60 min or more, and significantly decreased SICI immediately after. Conversely contrast, the PRMR significantly decreased immediately after, and SEPs were unchanged.
UNASSIGNED: These results suggest that simultaneous afferent inputs from different stimulus positions critically induce primary motor cortex plasticity. The combined stimulation of NMES with tsDCS may facilitate the development of a new neurorehabilitation technique.