(900) Vestibular Perception Performance and Relation with Falls, Balance and Gait in Older Adults

Introduction: Current clinical techniques for vestibular assessment rely primarily on assessing the strength of the vestibulo-ocular reflex. There are no universally available measures of vestibular perception. Understanding perception and vestibular contributions to spatial orientation may define clinical phenotypes of aging and disease. Here, we describe a novel vestibular-driven spatial orientation task that is clinically accessible and its performance in older adults.

Methods: This study is part of an on-going observational case-control study (Feb 2024-present). 158 adults >60 years of age with (n=82) or without a fall (n=76) in the last year underwent a series of measurements aimed at understanding their perception of spatial orientation about the yaw axis via a rotary chair by rating their maximum angular displacement. Visual and auditory input were eliminated via vision-denied goggles and broadband noise via headphones.

Results: Mean percent error across condition was 34.9 (SD=21.1), 19.7 (21.0), and 14.5% (15.8) for small, medium, and large displacements respectively. Repeated measures MANOVA revealed no significant difference between fallers and non-fallers (p>0.05); however, a main within subject effect of spatial orientation condition was observed (F=4.1, p=0.02) with larger percent error for smaller displacements. There was no significant correlation observed between spatial orientation conditions and FGA scores, gait speed, or the activity specific balance confidence score. In linear regression modelling, only cognition and age predicted each of the functional outcomes.

Conclusions: Despite, spatial orientation being multi-sensory, participants were able to estimate their spatial orientation using primarily vestibular cues with relative precision. No differences in performance based on falls status was observed and no correlation to broad measures of physical function. These results underscore the complex relation between perception and physical function and highlight a need for further investigation of multisensory integration and performance among those with vestibular disease.