The Effects of Stochastic Vestibular Stimulation on Gait Dysfunction in Parkinson’s Disease

Abstract

Parkinson’s disease PD is the second most common neurodegenerative disorder [1] and, while pharmacological interventions are highly effective, gait dysfunction is often resistant to levodopa treatment [2]. The vestibular system detects information on balance and posture. Galvanic vestibular stimulation (GVS) has been shown to improve locomotor stability in healthy individuals [3]. This study therefore aims to investigate potential therapeutic effects of GVS in PD Patients as compared to healthy controls. Stimulation was applied with a white noise signature at an optimal amplitude to maximize gait velocity. Five PD subjects were compared to five healthy subjects at baseline and after stimulation onset. PD subjects also underwent thirty minutes of continuous white noise GVS and were revaluated at the middle and end of these thirty minutes to determine if the duration of stimulation affected the efficacy of the stimulation. GVS did not significantly affect spatiotemporal or bilateral coordination parameters of gait in either group. Furthermore, gait in PD subjects did not vary significantly from the gait characteristics of healthy controls. These results contradict current findings in the field but may be reconciled by considering the role of vestibular information in medicated PD subjects during walking. Prior findings show greater effects of GVS with balance perturbation, so while medicated PD subjects may not show improved gait dynamics with GVS, future studies are required to definitively show GVS is ineffective in improving gait dysfunction in PD.