Functional Neural Correlates of Slower Gait among Older Adults with Mild Cognitive Impairment

Background Subtle, but observable, changes in mobility often exist among older adults with mild cognitive impairment (MCI). Notably, these changes are not inconsequential. Therefore, there is a strong interest to better understand the underlying neural correlates of gait slowing among older adults with MCI. In this study, we aimed to characterize patterns of functional connectivity associated with slower gait speed in older adults with MCI. Methods Forty-nine participants aged 60 years and older with MCI were included in the cross-sectional study. All participants underwent assessments of gait speed and resting state functional magnetic resonance imaging. Results In this sample of older adults with MCI, slower usual gait was characterized by altered connectivity between the sensorimotor network (SMN) and the frontoparietal network (FPN) (p <.05)-specifically, slower usual gait was associated with greater connectivity between the supplementary motor area (SMA) and the bilateral ventral visual cortices (p =.01); lower connectivity between the SMA and the bilateral superior lateral occipital cortex (p <.01); and lower connectivity between the SMA and the bilateral frontal eye field (p <.01). Conclusion Altered inter-network functional connectivity between the SMN and FPN may be a neural mechanism for slowing of gait in older adults with MCI.