Sleep disorders and Alzheimer's disease pathophysiology: The role of the Glymphatic System. A scoping review.

ABSTRACT

BACKGROUND: Alzheimer's disease (AD) is highly intertwined with sleep disturbances throughout its whole natural history. Sleep consists of a major compound of the functionality of the glymphatic system, as the synchronized slow-wave activity during NREM facilitates cerebrospinal and interstitial long-distance mixing. OBJECTIVE: The present study undertakes a scoping review of research on the involvement of the glymphatic system in AD-related sleep disturbances. DESIGN: we searched Medline, Embase, PsychInfo and HEAL-link databases, without limitations on date and language, along with reference lists of relevant reviews and all included studies. We included in vivo, in vitro and post-mortem studies examining glymphatic implications of sleep disturbances in human populations with AD spectrum pathology. A thematic synthesis of evidence based on the extracted content was applied and presented in a narrative way. RESULTS: In total, 70 original research articles were included and were grouped as following a) Protein aggregation and toxicity, after sleep deprivation, along with its effects on sleep architecture, b) Glymphatic Sequalae in SDB, yielding potential glymphatic markers c) Circadian Dysregulation, d) Possible Interventions. CONCLUSIONS: this review sought to provide insight into the role of sleep disturbances in AD pathogenesis, in the context of the glymphatic disruption.