Alzheimer’s disrupts circadian rhythms of plaque-clearing brain cells

Alzheimer’s disease is notorious for scrambling patients’ daily rhythms. Restless nights with little sleep and increased napping during the day are early indicators of disease onset, while sundowning, or confusion later in the day, is typical for later stages of the disease. These symptoms suggest a link between the progression of the disease and the circadian system — the body’s internal clock that controls our sleep and wake cycle — but scientists did not know the full nature of the connection.