Deep white matter hyperintensities, microstructural integrity and dual task walking in older people

Abstract

To examine neural, physiological and cognitive influences on gait speed under single and dual-task conditions. Sixty-two community-dwelling older people (aged 80.0 ± 4.2 years) participated in our study. Gait speed was assessed with a timed 20-meter walk under single and dual-task (reciting alternate letters of the alphabet) conditions. Participants also underwent tests to estimate physiological fall risk based on five measures of sensorimotor function, cognitive function across five domains, brain white matter (WM) hyperintensities and WM microstructural integrity by measuring fractional anisotropy (FA). Univariate linear regression analyses showed that global physiological and cognitive measures were associated with single (β = 0.594 and β=-0.297, respectively) and dual-task gait speed (β = 0.306 and β=-0.362, respectively). Deep WMHs were associated with dual-task gait speed only (β = 0.257). Multivariate mediational analyses showed that global and executive cognition reduced the strength of the association between deep WMHs and dual-task gait speed by 27% (β = 0.188) and 44% (β = 0.145) respectively. There was a significant linear association between single-task gait speed and mean FA values of the genu (β=-0.295) and splenium (β=-0.326) of the corpus callosum, and between dual-task gait speed and mean FA values of Superior Cerebellar Peduncle (β=-0.284), splenium of the Corpus Callosum (β=-0.286) and Cingulum (β=-0.351). Greater deep WMH volumes are associated with slower walking speed under dual-task conditions, and this relationship is mediated in part by global cognition and executive abilities specifically. Furthermore, both cerebellum and cingulum are related to dual-task walking due to their role in motor skill performance and attention, respectively.

Associations between handgrip strength and mild cognitive impairment in middle‐aged and older adults in six low‐ and middle‐income countries

“…8,9 This may be due to several mechanisms. 12 Finally, participation in physical activity improves muscular fitness 13 while it may be useful for maintaining neuronal health, 14 indicating that a person's lifestyle serves as a mediating factor to offset potential cognitive decline and physical frailty. 6 Second, white matter hyperintensities, which are a common neuropathological characteristic of MCI, 10 have been associated with greater cognitive 10 and muscular mass decline 11 and slowing of gait speed.…”

“…6 Second, white matter hyperintensities, which are a common neuropathological characteristic of MCI, 10 have been associated with greater cognitive 10 and muscular mass decline 11 and slowing of gait speed. 12 Finally, participation in physical activity improves muscular fitness 13 while it may be useful for maintaining neuronal health, 14 indicating that a person's lifestyle serves as a mediating factor to offset potential cognitive decline and physical frailty. From a public health and clinical perspective, the assessment of handgrip strength is of particular relevance as it is an objective measure of muscular fitness that is easily measurable at a low cost.…”

Heart Rate Variability Mainly Relates to Cognitive Executive Functions and Improves Through Exergame Training in Older Adults: A Secondary Analysis of a 6-Month Randomized Controlled Trial

“…Six temporal and spatial gait parameters were selected to identify associations with HRV indices, including “step time variability” and “step length variability” at preferred walking speed, as well as gait velocity under single- (ST) and dual-task (DT) conditions and at preferred and fast walking speeds: “velocity preferred-ST,” “velocity fast-ST,” “velocity preferred-DT,” and “velocity fast-DT.” The parameters were chosen based on findings, which have demonstrated their relation to brain functional or structural aspects (Tian et al, 2017 ; Ghanavati et al, 2018 ; Lucas et al, 2018 ). The GAITRite electronic walkway (CIR Systems, Havertown, PA, USA) with Platinum Version 4.0 software was used to assess gait parameters.…”

Understanding the association between psychomotor processing speed and white matter hyperintensity: A comprehensive multi‐modality MR imaging study

“…This phenomenon can be explained by WMH in different locations that are associated with white matter damage on different fibers. Further studies found that FA changes in the anterior thalamus radiata, corpus callosum, and cingulum are related to impaired executive functions in patients with cerebral small vessel disease (Bender, Völkle, & Raz, ; Ghanavati et al, ; Johnson et al, ; Papma et al, ; Tuladhar et al, ). Based on these findings, it has been proposed that slower processing speeds caused by WMH are a result of “disconnection,” arguing that disrupted fiber integrity slows information flow among different brain regions, leading to brain activity alterations.…”