A Virtual Reality Four-Square Step Test for Quantifying Dynamic Balance Performance in People with Persistent Postural Perceptual Dizziness

Persistent-postural perceptual dizziness (PPPD) is a recently-defined diagnosis of chronic vestibular symptoms, which is exacerbated by exposure to moving objects and self-motion but is typically undetectable by clinical tests. The current work evaluates the feasibility of a novel paradigm for evaluation of dynamic balance within complex visual environments in people with PPPD-the Virtual Reality Four Step Square Test (FSST-VR). The FSSTVR measures spatiotemporal head kinematics while subjects perform the FSST pattern of 8 steps in a predefined sequence in a virtual environment of varying levels of visual complexity. Eight healthy individuals and 3 people diagnosed with PPPD were asked to perform the FSST-VR while spatiotemporal head kinematics and heartrate were measured. Additionally, participants reported their anxiety levels and cybersickness. Results indicated that performance of the FSST-VR is feasible and did not aggravate symptoms for people with PPPD. Descriptive statistics further may suggest that people with PPPD move less smoothly and perform smaller steps in anteroposterior direction, corresponding with the visual stimuli flow in the virtual environment. Data collection is ongoing and may provide further evidence as to dynamic balance in people with PPPD within complex virtual environments that mimic visual load in daily living.