Deepen into sleep and wake patterns across Alzheimer's disease phenotypes.

Although, the clinical variants of Alzheimer's disease (AD) show distinct patterns of cognitive and behavioral decline, disease progression, and neuropathological features, it is unclear if this clinical heterogeneity extends to sleep-wake patterns. Sleep and wake disturbances are frequent in typical AD, often preceding memory loss and negatively impacting the quality of life of patients and caregivers alike. Still, sleep and wake disorders are often misdiagnosed and undertreated in typical AD. Better characterization of sleep-wake features in AD clinical variants is an unmet gap of high importance because these differing patterns may require tailored treatment strategies. Moreover, as wake-promoting neurons are located in subcortical nuclei and degenerate early in typical AD, contrasting the profiles of sleep-wake patterns in typical and atypical AD aids diagnosis and brings a unique opportunity to uncover the mechanisms underlying AD clinical variants at the subcortical level and mechanisms for selective neuronal vulnerability.