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

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 (R), 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 (Delta = -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 (Delta = -8.4 +/- 6.2; P = .0022) and 24hs-diastolic blood pressure (Delta = -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.

Automated summary

The study suggests that transcranial direct current stimulation (tDCS) can lead to positive acute adjustments in cardiac autonomic control and reduced 24-hour blood pressure values in hypertensive patients. These results may indicate a potential future application of brain stimulation (tDCS) in treating refractory hypertension syndromes.