Effect of transcranial direct current stimulation on hemodynamic parameters in resistant hypertensive subjects

Abstract

Resistant hypertension (RH) is a multifactorial condition defined as high blood pressure (BP) in spite of concurrent use of three or more antihypertensive drugs of different classes, combined at optimal doses and including a diuretic. The mechanisms of resistance to antihypertensive treatment are not fully elucidated, but it has been associated to hyperactivity of sympathetic nervous system (SNS). Invasive therapies have been development for the treatment of RH, but SNS hyperactivity remains as a challenge in clinical practice. Thus, the use of cerebral stimulation techniques, such as non-invasive transcranial direct current stimulation (tDCS) on cortex in RH subjects seems promising due to potential modulation of BP. Moreover, previous studies have shown the reduction of both systolic and diastolic BP after tDCS on cerebral cortex. This study aims primarily to get the essential training for the DC Stimulation Plus-SHAM mode (NeuroConn GmbH, Germany), which will be performed on Laboratory of Neuromodulation (Harvard Medical School). Secondly, we aim to evaluate whether the use of tDCS is able to regulate hemodynamic parameters, such as BP levels in RHTN. This double blind crossover study will included 20 patients allocated into two groups (1) placebo-sham follow by tDCS intervention for 1 week and (2) tDCS intervention follow by placebo-sham for 1 week, with 1-week period between both procedures. The office BP will be assessed in the pre- and post-period of tDCS and placebo-sham, but hemodynamic parameters (Finometer System) will be simultaneously evaluated during tDCS and placebo protocol. We hypothesize that the tDCS treatment after 1 week reduces BP levels in RH patients.