Why might advanced Alzheimer's patients develop sleep disturbances?

Advanced Alzheimer's patients may develop sleep disturbances due to a combination of factors, including changes in circadian rhythms, physical discomfort, and the effects of medications.

As Alzheimer's progresses, individuals often experience disruptions in their internal body clock, which can lead to irregular sleep patterns. This alteration in circadian rhythms can cause confusion about when to sleep and when to be awake, contributing to insomnia or fragmented sleep.

Additionally, physical discomfort is common in patients with advanced Alzheimer's, whether from coexisting medical conditions, lack of mobility, or side effects of medications that may impact sleep quality. Certain medications prescribed to manage symptoms of Alzheimer's or related health issues can also contribute to sleep disturbances.

Overall, the interplay of these elements—circadian rhythm changes, physical discomfort, and medication effects—makes option B the most comprehensive and accurate explanation for sleep disturbances in advanced Alzheimer's patients.