A systematic review of MRI studies examining the relationship between physical fitness and activity and the white matter of the ageing brain

Abstract

Higher levels of physical fitness or activity (PFA) have been shown to have beneficial effects on cognitive function and grey matter volumes in older adults. However, the relationship between PFA and the brain's white matter (WM) is not yet well established. Here, we aim to provide a comprehensive and systematic review of magnetic resonance imaging studies examining the effects of PFA on the WM of the ageing brain. Twenty-nine studies were included in the review: eleven examined WM volume, fourteen WM lesions, and nine WM microstructure. While many studies found that higher levels of PFA were associated with greater WM volumes, reduced volume or severity of WM lesions, or improved measures of WM microstructure, a number of negative findings have also been published. Meta-analyses of global measures of WM volume and WM lesion volume yielded significant, but small, effect sizes. Overall, we found evidence for cautious support of links between PFA and WM structure, and highlighted key areas for future research including the extent to which the relationship between PFA and WM structure is anatomically specific, the influence of possible confounding factors, and the relationship between PFA, WM and cognition.

Imaging and neuropsychological correlates of white matter lesions in different subtypes of Mild Cognitive Impairment: A systematic review

“…The findings of the studies reviewed in this article concur with the consensus in the literature on MCI, in which the microstructural change in the white matter of MCI are extensive and affects various brain regions (Radanovic et al, 2013;Sexton et al, 2016). For instance, significant changes in the white matter microstructure were reported in the corpus callosum, fornix, cingulum, parahippocampal region, and longitudinal and uncinate fasciculus in both AD and MCI individuals (Clerx, Visser, Verhey, & Aalten, 2012).…”

White Matter Integrity Declined Over 6-Months, but Dance Intervention Improved Integrity of the Fornix of Older Adults

“…The small deviations in magnitude of change seem to depend on analysis method of the diffusion data: skeleton-based used by Sexton et al (2016), Voss et al (2013b), and current study, tract-based used by Storsve et al (2016) and Rieckmann et al (2016). In addition, sample's age may influence the observed FA decline.…”

Aging and Alzheimer’s disease: Comparison and associations from molecular to system level

“…A combination of exercise and cognitive enrichment in mice increases protective effects against synaptotoxicity of Aβ in the hippocampus (Li et al, 2013). However, the benefits from exercise or cognitive stimulation are not consistent across studies (Sexton et al, 2016), and thus, standardized protocols and outcome measures are needed for this field (Duzel, van Praag, & Sendtner, 2016). …”