OPTOKINETIC STIMULATION IN THE REHABILITATION OF VISUALLY INDUCED DIZZINESS IN PEOPLE WITH VESTIBULAR DISORDERS: A SYSTEMATIC REVIEW

J.H.J. Law¹, H.Y. Koh¹, A.H. Kua¹

¹National University Hospital, Singapore, Singapore

Background: Visually Induced Dizziness (VID) is defined by the Bárány Society as symptoms triggered by a complex, distorted, large field or moving visual stimulus. It has been found that people with VID have increased visual dependence and difficulty in resolving conflict between visual and vestibulo-proprioceptive inputs.They have been shown to display abnormally large sway responses to visual motion.This reduces the ability to participate in activities, leading to a reduced quality of life and psychological wellbeing. Optokinetic stimulation (OKS) has been found to be effective in treating people with VID by providing graded exposure to visual motion, resulting in a decreased over-reliance on visual input in favour of vestibular and proprioceptive input.

Purpose: There are currently no recommendations on the optimum method of OKS in people with vestibular disorders, in terms of mode of delivery and dosage. The aim of this systematic review is to determine the effect of OKS on symptoms in people with vestibular disorders, with a specific focus on people with VID.

Methods: A systematic review was conducted using 3 electronic databases, CINAHL, PubMed and PEDRO, from 2000 up to Dec 2021. Outcome measures evaluating subjective symptoms were extracted from the studies. The methodological quality of the included studies was assessed using the Physiotherapy Evidence Database (PEDro) scale.

Results: Eleven randomised control trials, reported in 12 records, fulfilled the inclusion criteria. All of the studies were considered to have ‘good’ methodological quality according to the PEDro scale. All studies showed significant improvement in symptoms in the intervention and comparison groups. Three of the included studies found that additional exposure to OKS further reduced symptoms for people with unilateral vestibular dysfunction. In the 5 studies that specifically evaluated subjects with VID, no significant differences were found between the addition of OKS to conventional vestibular rehabilitation.
All modes of OKS evaluated in the studies were found to be effective in reducing symptoms, including affordable and commercially available options like video playback or virtual reality headsets. Regardless of treatment period or duration of exposure to OKS, vestibular symptoms were significantly improved in the included studies. OKS was also found to be safe to use for vestibular rehabilitation with little to no side effects and adverse events reported across the included studies.

Conclusions: The use of OKS alone is as effective as conventional vestibular rehabilitation in improving vestibular symptoms for people with vestibular disorders.
Further research comparing different dosages of OKS should be done to determine the optimal duration and frequency. More research should also be done to evaluate the use of commercially available devices and games to improve the translation of research findings into clinical practice.

Implications: In recent years, especially with the advent of COVID-19, there is an increase in digitalization and teledelivery of rehabilitation, with high acceptance rates amongst therapists. Devices such as immersive virtual reality headsets are now more commercially accessible, allowing for usage as part of home exercise programs. OKS could be a useful adjunct for traditional vestibular rehabilitation. OKS could also increase enjoyment levels and adherence towards therapy, overcoming barriers to exercise.

Funding acknowledgements: No funding was received.

Keywords:
Optokinetic Stimulation
Vestibular rehabilitation
Visually induced dizziness

Topics:
Neurology
Disability & rehabilitation
Health promotion & wellbeing/healthy ageing/physical activity

Did this work require ethics approval? No

Reason: Ethical approval was not requiredbecause this submission involves a systematic review, where data was retrieved and synthesised from already published studies. There was no direct interaction or interference with subjects.