Multivariate Analyses of Balance Test Performance, Vestibular Thresholds, and Age

Abstract

We previously published vestibular perceptual thresholds and performance in the Modified Romberg Test of Standing Balance in 105 healthy humans ranging from ages 18 to 80 (1). Self-motion thresholds in the dark included roll tilt about an earth-horizontal axis at 0.2 and 1 Hz, yaw rotation about an earth-vertical axis at 1 Hz, y-translation (interaural/lateral) at 1 Hz, and z-translation (vertical) at 1 Hz. In this study, we focus on multiple variable analyses not reported in the earlier study. Specifically, we investigate correlations (1) among the five thresholds measured and (2) between thresholds, age, and the chance of failing condition 4 of the balance test, which increases vestibular reliance by having subjects stand on foam with eyes closed. We found moderate correlations (0.30–0.51) between vestibular thresholds for different motions, both before and after using our published aging regression to remove age effects. We found that lower or higher thresholds across all threshold measures are an individual trait that account for about 60% of the variation in the population. This can be further distributed into two components with about 20% of the variation explained by aging and 40% of variation explained by a single principal component that includes similar contributions from all threshold measures. When only roll tilt 0.2 Hz thresholds and age were analyzed together, we found that the chance of failing condition 4 depends significantly on both (p = 0.006 and p = 0.013, respectively). An analysis incorporating more variables found that the chance of failing condition 4 depended significantly only on roll tilt 0.2 Hz thresholds (p = 0.046) and not age (p = 0.10), sex nor any of the other four threshold measures, suggesting that some of the age effect might be captured by the fact that vestibular thresholds increase with age. For example, at 60 years of age, the chance of failing is roughly 5% for the lowest roll tilt thresholds in our population, but this increases to 80% for the highest roll tilt thresholds. These findings demonstrate the importance of roll tilt vestibular cues for balance, even in individuals reporting no vestibular symptoms and with no evidence of vestibular dysfunction.

Age-related reweighting of visual and vestibular cues for vertical perception

“…Interestingly, they found this value to double when comparing older subjects (60 -80 yr) to younger subjects (18 -40 yr; see their Table 4), which is a pattern consistent with the present observations. Karmali et al (2017) reported a significant correlation between the roll tilt thresholds, age, and the outcome of the modified Romberg balance test, in which a subject must stand on foam with eyes closed for 30 s. The larger the thresholds, the larger the chance of failing the test, even in individuals reporting no vestibular symptoms and with no evidence of vestibular dysfunction. These findings demonstrate the importance of roll-tilt vestibular cues for balance.…”

Variability in the Vestibulo-Ocular Reflex and Vestibular Perception

“…For example, perceptual motion thresholds (e.g., did I perceive a leftward or rightward motion?) in the dark (Benson et al, 1986, Gu et al, 2007, Grabherr et al, 2008, Butler et al, 2010, Roditi and Crane, 2012) are sensitive to disease (Lewis et al, 2011, Valko et al, 2012, Cousins et al, 2013), balance performance (Bermudez Rey et al, 2016, Karmali et al, 2017) and age (Bermudez Rey et al, 2016). Similarly, eye movement thresholds elicited in response to head motion (the vestibulo-ocular reflex; VOR) are affected by vestibular damage (Cousins et al, 2013).…”

Association between Bone Metabolism and Vestibular Problems in the Modified Romberg Test: Data from the 2009–2010 Korean National Health and Nutrition Examination Survey

“…Thus, the potential of misdiagnosis could not be completely excluded in this study. However, a modified Romberg test condition of four has been found to detect vestibular dysfunction with high test performance, since examinees are made to stand on memory foam with their eyes closed, forcing them to rely on their vestibular functions to maintain balance [41,42]. Lastly, the unconcerned confounders, such as inner ear diseases cannot be accessed in this study.…”