Differences in the association between white matter hyperintensities and gait performance among older adults with and without cognitive impairment.

AIM: Gait impairment implies subtle cognitive impairment (CI) and is associated with severity of white matter hyperintensities (WMHs). However, cognitive differences in such an association are not yet fully understood. This study examined the association between WMHs and gait performance among three cognitively different older groups. METHODS: Gait performance and WMHs were assessed in 150 community-dwelling older adults, comprising 53 with CI (Mini-Mental State Examination [MMSE] score <24), 63 with mild CI (MMSE score ≥24 and Montreal Cognitive Assessment [MoCA] score <25), and 34 who were cognitively normal or preserved (MMSE ≥24 and MoCA score ≥25). Gait velocity and variability were assessed on a 5-m electronic walkway. Furthermore, WMH volume was derived by automated segmentation using 1.5 T magnetic resonance imaging. RESULTS: Adjusted multiple regression analyses showed that greater WMHs were associated with slower gait velocity and greater temporal (stride time) and spatial (stride and step lengths) variabilities among older adults with CI. In contrast, WMH was only associated with spatial variability in older adults with mild CI and in cognitively normal or preserved older adults. CONCLUSIONS: Our findings suggest that gait variability measures are more sensitive to subtle underlying neurological pathologies including WMHs in older adults. The cognitive-dependent differences found in the association between WMHs and gait performance suggests that the level of cognitive function interferes with the association between WMH and gait performance. Geriatr Gerontol Int 2021; ••: ••-••.