Vestibular perception, balance impairment, and fall risk in community-dwelling older adults.

BACKGROUND: Vestibular complaints are common in older adults and are linked to imbalance and falls. Some older adults show impaired vestibular perception despite preserved peripheral-reflex ['vestibular agnosia (VA)']. Yet it remains unclear if VA is independently linked to imbalance and falls in otherwise healthy older adults. We therefore investigated the prevalence of VA in community-dwelling older adults, and examined its association to balance and prospective falls.

METHODS: Vestibular perceptual thresholds were measured during yaw-plane rotational chair testing. Postural sway and instrumented Timed-Up-and-Go were assessed using wearable sensors, and falls were recorded prospectively over six-months. VA was identified using K-means clustering. Multivariable regressions examined associations between perceptual thresholds and balance outcomes; logistic and negative binomial regressions evaluated associations with prospective falls.

RESULTS: Among 166 participants (75.4 years; 81.9% female), 18.7% were classified as having VA. These individuals had worse cognition and somatosensation, and higher anxiety. Elevated (i.e. worse) vestibular perceptual thresholds were independently associated with greater sway velocity when standing on foam with eyes-open (adjusted β = 0.002, P = .03). Associations with other balance outcomes were attenuated after adjustment. Vestibular perceptual thresholds were not associated with prospective falls (odds of ≥1 fall: adjusted OR = 0.99, P = .65; fall counts: adjusted IRR = 1.02, P = .35).

CONCLUSIONS: Approximately one-fifth of healthy older adults exhibit VA. While elevated perceptual thresholds are independently associated with poorer balance, they did not predict falls. Further research is needed to determine whether vestibular perceptual testing provides additional information beyond standard balance assessments for fall-risk prediction in community-dwelling healthy older adults.