Finding a Balance: A Systematic Review of the Biomechanical Effects of Vestibular Prostheses on Stability in Humans

Abstract

The vestibular system is located in the inner ear and is responsible for maintaining balance in humans. Bilateral vestibular dysfunction (BVD) is a disorder that adversely affects vestibular function. This results in symptoms such as postural imbalance and vertigo, increasing the incidence of falls and worsening quality of life. Current therapeutic options are often ineffective, with a focus on symptom management. Artificial stimulation of the vestibular system, via a vestibular prosthesis, is a technique being explored to restore vestibular function. This review systematically searched for literature that reported the effect of artificial vestibular stimulation on human behaviours related to balance, using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) technique. A total of 21 papers matched the inclusion criteria of the literature search conducted using the PubMed and Web of Science databases (February 2019). The populations for these studies included both healthy adults and patients with BVD. In every paper, artificial vestibular stimulation caused an improvement in certain behaviours related to balance, although the extent of the effect varied greatly. Various behaviours were measured such as the vestibulo-ocular reflex, postural sway and certain gait characteristics. Two classes of prosthesis were evaluated and both showed a significant improvement in at least one aspect of balance-related behaviour in every paper included. No adverse effects were reported for prostheses using noisy galvanic vestibular stimulation, however, prosthetic implantation sometimes caused hearing or vestibular loss. Significant heterogeneity in methodology, study population and disease aetiology were observed. The present study confirms the feasibility of vestibular implants in humans for restoring balance in controlled conditions, but more research needs to be conducted to determine their effects on balance in non-clinical settings.

Vestibular prosthesis: from basic research to clinics

“…In addition, it is essential to consider the postural responses related to maintaining static and dynamic equilibrium and cognitive processes that are fundamental elements of locomotor behavior in humans ( Hitier et al, 2014 ). A systematic review of the biomechanical outcome of invasive and non-invasive electrical vestibular stimulation, including 19 Q1 and 2 Q2 research papers, found just one publication on postural evaluation after VI ( Haxby et al, 2020 ).…”

Leveraging Technology for Vestibular Assessment and Rehabilitation in the Operational Environment: A Scoping Review

“…Is intralabyrinthine medication delivery also possible in combination with vestibular implantation? Systematic reviews have found that vestibular implants can restore VOR function [67] and balance [68] in patients with bilateral vestibular loss. In the future, technological advances may enable an externally applied device to similarly replace lost vestibular function to expedite an injured service member's return to duty.…”

Scoping out noisy galvanic vestibular stimulation: a review of the parameters used to improve postural control

“…To our knowledge, this is the first scoping review to collate, summarize and report on the different nGVS parameters used to improve postural control. Consensus on the optimum parameters has been identified as a critical next step to further this research ( Herssens and McCrum, 2019 ; Haxby et al, 2020 ; Stefani et al, 2020 ; Lajoie et al, 2021 ; Pires et al, 2022 ). In this review, we look at the current evidence around parameter choice and give recommendations on future reporting to add rigor to nGVS research and facilitate meaningful comparison between studies.…”