Physical performance and a test of gaze stabilization in older adults

Objective: The purpose of this study was to assess the feasibility of a standardized gaze stabilization test (GST) as an indicator of vestibular function in community-dwelling older adults and to examine the relationship between gaze stabilization and physical performance. Design: Descriptive, cross-sectional. Setting: Tertiary medical center. Subjects: Eighty-six healthy older adults (22 men) of mean (standard deviation [SD]) age 76.8 (5.8) years were recruited from the Pittsburgh community. Main Outcome Measures: Performance on the GST, measures of physical performance (standing balance, chair rises, and gait speed individually and combined into the Short Physical Performance Battery) and self-reported balance. Results: Whereas more than 90% of participants completed testing in the pitch and yaw planes, only 85% (73 of 86) had interpretable scores due to prolonged perception time independent of vestibulo-ocular reflex. The mean (SD) head movement velocity in the pitch plane was 94.5 (26.7) degrees per second, whereas the mean (SD) head movement velocity in the yaw plane was 95.5 (29.3) degrees per second. There was a strong association between age and GST performance in the pitch and yaw planes (r = 0.68; p < 0.001). Poor GST performance in the yaw plane was associated with balance capacity with eyes closed. Additionally, there was a trend toward an association between self-reported balance and GST performance in both pitch (p = 0.08) and yaw planes (p = 0.10). Conclusion:: Although most older adults completed GST testing, estimates were not interpretable in almost 15% due to prolonged perception time. Gaze stabilization test in the yaw plane was worse than previously reported in healthy older adults and was associated with poor ability to balance with eyes closed. Self-reported balance tended to be associated with an objective assessment of vestibulo-ocular reflex in this population of older adults.