Our bodies naturally follow a 24-hour rhythm known as the circadian cycle—a built-in clock that helps us know when to sleep, eat, and stay alert. For someone living with Alzheimer’s Disease, that clock often starts to break down, causing not only sleep problems but also behavioral changes known as sundowning.
Recent research from Washington University School of Medicine in St. Louis has revealed that Alzheimer’s Disease doesn’t just affect memory, it also disrupts the brain’s internal brain clock system. This new study, published in Nature Neuroscience, found that the buildup of amyloid plaques disrupts the normal daily rhythms in the brain’s key support cells:
- Microglia (the brain’s immune and cleanup crew)
- Astrocytes (cells that help neurons function and communicate)
In a healthy brain, these cells work on a strict schedule, clearing away waste (like amyloid) during sleep. The research found that Alzheimer’s scrambles this schedule. The cells’ “on-off” switches for hundreds of genes get confused, weakening their ability to do their jobs. When these cells lose their rhythm, this creates a vicious cycle: the disease disrupts sleep, and the resulting poor sleep prevents the brain from clearing away amyloid waste, which in turn allows the plaques to build up and worsen the disease.
Although there’s no cure for sundowning, maintaining a healthy daily rhythm can make a meaningful difference. Here are some ways to support better rest and reduce confusion:
Manage the Environment
- A clean, uncluttered space is inherently more relaxing.
- Turn off or lower the TV and music. A quiet environment can prevent overstimulation.
- Adjust the Lighting, as the sun begins to set, close the curtains and switch from bright overhead lights to softer lamps. This creates a clear visual cue that day is ending and nighttime is beginning.
Build a Daily Rhythm
- Create a Simple Schedule: A predictable routine for waking, meals, and activities provides a sense of security and structure.
- Get Sunlight Exposure: Spend time outside or near a bright window every day, if possible. Exposure to daylight is essential for regulating the internal clock.
- Encourage Activity: A daily walk or other physical activities can help burn off excess energy and improve nighttime sleep.
- Keep Naps Short: If naps are necessary, keep them brief and earlier in the day. Long naps can make it much harder to sleep through the night.
