ABSTRACT

Purpose: Transcranial direct current stimulation (tDCS) seems to positively modulate the autonomic nervous system in different clinical conditions and healthy subjects; however, its effects on hypertensive (HTN) patients are not completely known. This study aimed to evaluate the effects of a tDCS or SHAM session (20 min) on blood pressure (BP) and autonomic variables of HTN patients.

Materials and Methods: Subjects (n = 13) were randomly submitted to SHAM and tDCS sessions (1 week of washout). Hemodynamic and autonomic variables were measured at baseline, during, and immediately after tDCS or SHAM stimulation (Finometer®, Beatscope). Ambulatory BP measurement (ABPM) was evaluated after the experimental period.

Results: Hemodynamic variables were not changed by tDCS, except for the fall in peripheral vascular resistance (Δ = −1696.51 ± 204.65 dyn.s/cm5). After the tDCS, sympathetic modulation was decreased (−61.47%), and vagal modulation was increased (+38.09%). Such acute autonomic changes may have evoked positive results observed in 24 hs-systolic blood pressure (Δ = −8.4 ± 6.2; P = .0022) and 24hs-diastolic blood pressure (Δ = −5.4 ± 4.2; P = .0010) in tDCS subjects compared with that in SHAM.

Conclusion: These findings suggest that the tDCS could promote positive acute adjustments on cardiac autonomic control and reduced values on 24-hs BP of HTN patients. More than a proof-of-concept, these results may point out to the future, where brain stimulation (tDCS) can be used to HTN syndromes, such as refractory HTN.

摘要

目的：经颅直流电刺激（tDCS）似乎在不同的临床情况和健康受试者中积极调节自主神经系统。但是，它对高血压（HTN）患者的作用尚不完全清楚。这项研究旨在评估tDCS或SHAM疗程（20分钟）对HTN患者的血压（BP）和自主变量的影响。

材料和方法：受试者（n = 13）随机接受SHAM和tDCS疗程（冲洗1周）。在基线，tDCS或SHAM刺激过程中和之后立即测量血流动力学和自主神经变量（Binscope）。实验期后评估动态血压测量（ABPM）。

结果：除了外周血管阻力下降（Δ= −1696.51±204.65 dyn.s / cm5）外，tDCS并未改变血流动力学变量。在tDCS之后，交感调节降低（-61.47％），迷走神经调节升高（+ 38.09％）。这种急性自主性改变可能诱发了在24hs收缩压（Δ= -8.4±6.2; P = .0022）和24hs舒张压（Δ= −5.4±4.2; P = .0010）的阳性结果tDCS受试者与SHAM中的受试者进行了比较。

结论：这些发现表明，tDCS可以促进HTN患者心脏自主神经控制的积极急性调整，并降低其24 h BP值。这些结果不只是概念验证，还可以指出未来，脑刺激（tDCS）可以用于HTN综合征，例如难治性HTN。