Association between visuospatial ability and vestibular function in the Baltimore Longitudinal Study of Aging

Objectives To investigate the relationship between vestibular loss associated with aging and age-related decline in visuospatial function. Design Cross-sectional analysis within a prospective cohort study. Setting Baltimore Longitudinal Study of Aging (BLSA). Participants Community-dwelling BLSA participants with a mean age of 72 (range 26-91) (N = 183). Measurements Vestibular function was measured using vestibular-evoked myogenic potentials. Visuospatial cognitive tests included Card Rotations, Purdue Pegboard, Benton Visual Retention Test, and Trail-Making Test Parts A and B. Tests of executive function, memory, and attention were also considered. Results Participants underwent vestibular and cognitive function testing. In multiple linear regression analyses, poorer vestibular function was associated with poorer performance on Card Rotations (P =.001), Purdue Pegboard (P =.005), Benton Visual Retention Test (P = 0.008), and Trail-Making Test Part B (P =.04). Performance on tests of executive function and verbal memory were not significantly associated with vestibular function. Exploratory factor analyses in a subgroup of participants who underwent all cognitive tests identified three latent cognitive abilities: visuospatial ability, verbal memory, and working memory and attention. Vestibular loss was significantly associated with lower visuospatial and working memory and attention factor scores. Conclusion Significant consistent associations between vestibular function and tests of visuospatial ability were observed in a sample of community-dwelling adults. Impairment in visuospatial skills is often one of the first signs of dementia and Alzheimer's disease. Further longitudinal studies are needed to evaluate whether the relationship between vestibular function and visuospatial ability is causal.