Circadian Rhythms, Sleep, and Disorders of Aging

Sleep–wake cycles are known to be disrupted in people with neurodegenerative disorders. These findings are now supported by data from animal models for some of these disorders, raising the question of whether the disrupted sleep/circadian regulation contributes to the loss of neural function. As circadian rhythms and sleep consolidation also break down with normal aging, changes in these may be part of what makes aging a risk factor for disorders like Alzheimer's disease (AD). Mechanisms underlying the connection between circadian/sleep dysregulation and neurodegeneration remain unclear, but several recent studies provide interesting possibilities. While mechanistic analysis is under way, it is worth considering treatment of circadian/sleep disruption as a means to alleviate symptoms of neurodegenerative disorders.

TrendsSleep and circadian dysfunction are increasingly being associated with neurodegenerative disorders. Earlier studies with human subjects are now supported by findings in genetic models.Circadian and sleep circuits are damaged in disorders like Huntington's and Parkinson's disease and disrupted sleep/circadian rhythms may exacerbate disease pathology. Thus, these two processes may feed back on each other.Metabolic factors may provide a mechanistic link between circadian rhythms, sleep, and neurodegenerative disorders.Sleep and circadian dysregulation could provide a screening tool to identify populations at risk for neurodegenerative disorders.