AUTHOR=Demnitz Naiara , Zsoldos Enikő , Mahmood Abda , Mackay Clare E. , Kivimäki Mika , Singh-Manoux Archana , Dawes Helen , Johansen-Berg Heidi , Ebmeier Klaus P. , Sexton Claire E. TITLE=Associations between Mobility, Cognition, and Brain Structure in Healthy Older Adults JOURNAL=Frontiers in Aging Neuroscience VOLUME=9 YEAR=2017 URL=https://www.frontiersin.org/journals/aging-neuroscience/articles/10.3389/fnagi.2017.00155 DOI=10.3389/fnagi.2017.00155 ISSN=1663-4365 ABSTRACT=

Mobility limitations lead to a cascade of adverse events in old age, yet the neural and cognitive correlates of mobility performance in older adults remain poorly understood. In a sample of 387 adults (mean age 69.0 ± 5.1 years), we tested the relationship between mobility measures, cognitive assessments, and MRI markers of brain structure. Mobility was assessed in 2007–2009, using gait, balance and chair-stands tests. In 2012–2015, cognitive testing assessed executive function, memory and processing-speed; gray matter volumes (GMV) were examined using voxel-based morphometry, and white matter microstructure was assessed using tract-based spatial statistics of fractional anisotropy, axial diffusivity (AD), and radial diffusivity (RD). All mobility measures were positively associated with processing-speed. Faster walking speed was also correlated with higher executive function, while memory was not associated with any mobility measure. Increased GMV within the cerebellum, basal ganglia, post-central gyrus, and superior parietal lobe was associated with better mobility. In addition, better performance on the chair-stands test was correlated with decreased RD and AD. Overall, our results indicate that, even in non-clinical populations, mobility measures can be sensitive to sub-clinical variance in cognition and brain structures.