Reduced thalamocortical facilitation of the motor cortex in PD leads to characteristic motor deficits such as bradykinesia. Recent research has highlighted improved motor function following tDCS, but a lack of neurophysiological evidence limits the progress of tDCS as an adjunctive therapy. Here, we tested the hypothesis that tDCS may modulate M1 hemodynamic activity in PD and healthy using functional near-infrared spectroscopy (fNIRS). In this randomized crossover experiment, fourteen PD and twelve healthy control participants attended three laboratory sessions and performed a regulated (3 Hz) right index finger tapping task before and after receiving tDCS. On each visit, participants received either anodal, cathodal, or sham tDCS applied over M1. Hemodynamic activity of M1 was quantified using fNIRS. Significant task related activity was observed in M1 and the inferior parietal lobe in PD and healthy (p < 0.05). PD additionally recruited the dorsal premotor cortex. During tDCS, while at rest, anodal and cathodal tDCS significantly increased the oxygenated hemoglobin concentration of M1 compared to sham (t₆₂ = 4.09 and t₆₂ = 4.25, respectively). Task related hemodynamic activity was unchanged following any tDCS intervention (p > 0.05). Task related hemodynamic activity of M1 is not modulated by tDCS in PD or healthy. During tDCS, both anodal and cathodal stimulation cause a significant increase of M1 oxygenation, the clinical significance of which remains to be clarified.

PD 中运动皮层的丘脑皮质促进作用降低会导致特征性运动缺陷，例如运动迟缓。最近的研究强调 tDCS 后运动功能得到改善，但缺乏神经生理学证据限制了 tDCS 作为辅助治疗的进展。在这里，我们使用功能性近红外光谱 (fNIRS) 测试了 tDCS 可能调节 PD 和健康人的 M1 血流动力学活动的假设。在这项随机交叉实验中，14 名 PD 和 12 名健康对照参与者参加了 3 次实验室会议，并在接受 tDCS 之前和之后执行了受调节的 (3 Hz) 右手食指敲击任务。每次访视时，参与者均接受在 M1 上应用的阳极、阴极或假 tDCS。M1 的血流动力学活动使用 fNIRS 进行量化。在 PD 和健康人的 M1 和顶下叶中观察到显着的任务相关活动（p < 0.05）。PD还招募了背侧前运动皮层。在 tDCS 期间，在休息时，与假手术相比，阳极和阴极 tDCS 显着增加了 M1 的氧合血红蛋白浓度（分别为 t ₆₂  = 4.09 和 t ₆₂  = 4.25）。任何 tDCS 干预后，任务相关的血流动力学活动均未改变 (p > 0.05)。在 PD 或健康人中，任务相关的 M1 血流动力学活动不受 tDCS 调节。在 tDCS 期间，阳极和阴极刺激都会导致 M1 氧合显着增加，其临床意义仍有待阐明。