Noisy vestibular stimulation increases gait speed in normals and in bilateral vestibulopathy

Abstract

Background: Galvanic vestibular stimulation delivered as zero-mean current noise (noisy GVS) has been shown to improve static and dynamic postural stability probably by enhancing vestibular information.

Objective: /Hypothesis: To examine the effect of an imperceptible level of noisy GVS on dynamic locomotion in normal subjects as well as in patients with bilateral vestibulopathy.

Methods: Walking performance of 19 healthy subjects and 12 patients with bilateral vestibulopathy at their preferred speed was examined during application of noisy GVS with an amplitude ranging from 0 to 1000 μA. The gait velocity, stride length and stride time were analyzed.

Results: Noisy GVS had significant effects on gait velocity, stride length and stride time in healthy subjects as well as in patients with bilateral vestibulopathy (p < 0.05). The optimal amplitude of noisy GVS improved gait velocity by 10.9 ± 1.2%, stride length by 5.7 ± 1.2% and stride time by 4.6 ± 7% (p < 0.0001) compared to the control session in healthy subjects. The optimal stimulus improved gait velocity by 12.8 ± 1.3%, stride length by 8.3 ± 1.1% and stride time by 3.7 ± 7% (p < 0.0001) in patients with bilateral vestibulopathy. The improved values of these parameters of locomotion by noisy GVS in the patients were not significantly different from those in healthy subjects in the control condition (p > 0.4).

Conclusion: Noisy GVS is effective in improving gait performance in healthy subjects as well as in patients with bilateral vestibulopathy.

Keywords: Bilateral vestibulopathy; Galvanic vestibular stimulation; Locomotion; Stochastic resonance.