Effects of Noisy Galvanic Vestibular Stimulation on Blood Pressure and Postural Sway in Healthy Adults: A Pilot Study.

BACKGROUND: Noisy galvanic vestibular stimulation (nGVS) has been shown to influence postural control, but its cardiovascular safety remains uncertain. Establishing tolerability and hemodynamic neutrality is essential for potential clinical use. OBJECTIVE: To examine the effects of nGVS on mean blood pressure (MBP) and postural sway in healthy young adults during upright standing. METHODS: Twenty-one healthy volunteers stood with eyes closed on a rubber mat for one minute while receiving sham or real nGVS (1 mA, 40 seconds). Postural sway was recorded with a force plate to obtain total path length (CoP-L), anteroposterior velocity (Vel-AP), and mediolateral velocity (Vel-ML). MBP was measured immediately after each trial with an automated sphygmomanometer. Outcomes were normalized to baseline, averaged within participants, and compared between conditions using paired analyses. Mixed-effects models explored associations between MBP and sway velocity. RESULTS: All participants reported no pain or dizziness (numeric rating scale, or NRS = 0), confirming tolerability. No significant differences were observed between sham and real nGVS for MBP or sway parameters (all p > 0.05, Cohen's dz < 0.4). Exploratory analyses suggested a weak correlation between MBP and Vel-ML under real nGVS, but this association was not significant when repeated measures were modeled. CONCLUSIONS: Brief 1 mA nGVS was imperceptible, safe, and produced no detectable changes in blood pressure or sway in healthy young adults. These findings provide preliminary evidence of cardiovascular safety and support further studies in clinical populations at risk of autonomic dysfunction or balance impairment.