Noisy galvanic vestibular stimulation has a greater ameliorating effect on posture in unstable subjects: a feasibility study

Abstract

Ameliorating effect of noisy galvanic vestibular stimulation (nGVS) on posture varies among subjects. In this feasibility study, we investigated the association between original postural instability and the ameliorating effect of nGVS on posture. Data were collected in a previously published study. Thirty healthy elderly were recruited. Two nGVS sessions (30 min or 3 h) were performed in a randomised order. The optimal intensity of nGVS, the most effective intensity for improving posture, was determined before each session. Posture was measured for 30 s during and after nGVS in the eyes-closed/foam rubber condition. The velocity, envelopment area, and root mean square of the centre of pressure movement without nGVS were significantly larger in the group with an optimal intensity than those in the group without an optimal intensity. There was a significant positive correlation between these values and the long-term ameliorating effects. The ratio of the values in the eyes-closed/foam rubber condition to those in the eyes-open condition was significantly larger in the group with an optimal intensity, and had a significant correlation with the long-term ameliorating effects. The ameliorating effects are greater in subjects who were originally unstable and in those whose postural stability was relatively independent of vestibular input.

Combining vestibular rehabilitation with noisy galvanic vestibular stimulation for treatment of bilateral vestibulopathy

“…There is so far no consensus about whether nGVS only acts during ongoing stimulation or whether it exhibits any plastic aftereffects after cessation of stimulation. In favor of the later assumption, Fujimoto et al reported in an uncontrolled study long-term effects of nGVS on postural stability that lasted up to 6 h after cessation of stimulation [ 7 ]. Later, placebo-controlled studies did not find any evidence for long-term effects of nGVS on vestibular function [ 14 , 20 ].…”

No Impact of Stochastic Galvanic Vestibular Stimulation on Arterial Pressure and Heart Rate Variability in the Elderly Population

“…Regarding the clinical significance of this study, our result provides evidence for the safety of using nGVS in elderly people. While previous studies report the effectiveness of nGVS ( Fujimoto et al, 2016 , 2018 , 2019 ; Inukai et al, 2018a , b ), they provide no evidence on its impact on AP and HR variability. In future studies, the effect of nGVS on AP and HR variability in patients with cardiocirculatory disorders, such as orthostatic hypotension, arrhythmia, and heart failure, should be tested further to ensure safety.…”

Noisy Galvanic Vestibular Stimulation Combined With a Multisensory Balance Program in Older Adults With Moderate to High Fall Risk: Protocol for a Feasibility Study for a Randomized Controlled Trial

“…This study is the first step toward determining whether noisy galvanic vestibular stimulation can effectively and safely enhance balance and stability in a balance retraining program. Preliminary evidence suggests that the use of subsensory noisy galvanic vestibular stimulation to enhance vestibular signals to the brain also improves stability during quiet standing and gait [ 4 , 20 , 21 , 25 , 26 ]. This study will assess the feasibility of administering a balance retraining program augmented by noisy galvanic vestibular stimulation for older adults at risk for falls.…”

“…However, this sustained effect has not been replicated consistently in other studies; Inukai et al [ 22 ] found a poststimulation effect in contrast to Nooristani et al [ 23 ] and Keywan et al [ 24 ] who did not. A secondary analysis by Fujimoto et al [ 21 ] discovered that noisy galvanic vestibular stimulation resulted in significantly greater improvements in participants who were more unsteady on initial assessment [ 25 ]. This suggests that either noisy galvanic vestibular stimulation has a greater effect on the hypofunctional vestibular system or that different noisy galvanic vestibular stimulation parameters and experimental designs play a role in these findings.…”