Sleep, rest -activity fragmentation and structural brain changes related to the ageing process

Increasing evidence suggests an association between typical age-related changes in sleep and brain structure. Here we review studies exploring the association between human histo-pathological and in vivo neuroimaging markers of brain structure and sleep-wake parameters in healthy older adults. Evidence from both large-scale epidemiological studies and in-lab quantification of specific sleep signatures are reviewed and advantages and pitfalls highlighted. Overall, the results point to an association between sleep-wake disruption and both local and diffuse changes in brain structure. The associative strength largely varies between studies and seems to partially depend on the sleep trait under investigation. The role of specific sleep-wake regulating mechanisms on human cognitive and brain fitness and more particularly their causal relationship remains to be disentangled. © 2019 Elsevier Ltd