Transcranial direct current stimulation modulates autonomic nervous system and reduces ambulatory blood pressure in hypertensives

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.

KEYWORDS:

• Hypertension
• Autonomic Modulation
• Transcranial Direct Current Stimulation (tDCS)
• Ambulatory Blood Pressure Measurement

Disclosure statement

The authors declare that they no have a potential conflict of interest.

Additional information

Funding

This study was supported by São Paulo Research Foundation (FAPESP) [grant #2017/21320/4; #2017/24726-1; #2016/18104-5]. This study was financed in part by the Coordenação de Aperfeiçoamento de Pessoal de Nível Superior – Brasil (CAPES) – Finance Code 001. BR and HMJ are fellowships from CNPq (BPQ-CNPq, #307646/2019-0).