Very interesting article on new research that could help explain the causes of Sundowning in elders. Many caregivers have struggled with the symptoms of sundowning with their patients. Hopefully this new research will shed some new light on the subject.
New research provides the best evidence to date that the late-day anxiety and agitation sometimes seen in older institutionalized adults, especially those with dementia, has a biological basis in the brain. The findings could help explain “sundowning,” a syndrome in which older adults show high levels of anxiety, agitation, general activity and delirium in late afternoon and evening, before they would normally go to bed. “It’s a big problem for caregivers. Patients can get aggressive and very disruptive,” said Tracy Bedrosian, lead author of the study and a doctoral student in neuroscience at Ohio State University.
“There have been a few clinical studies documenting sundowning, but until now there hasn’t been research in animals to see what’s going on in the brain to explain this. ”The new study found that aged mice showed significantly more activity and more anxiety-like behaviors in the hours before they would normally sleep when compared to middle-aged mice – just like sundowning in humans. In these aged mice, the researchers found changes in parts of their brain associated with attention, emotions, and arousal, all of which could be associated with the behavior seen in sundowning. In addition, mice that were genetically engineered to have an Alzheimer’s-like disease also showed more anxiety before sleep than did other mice.
“Some people have argued that sundowning could be explained just by a buildup of frustration of older people who couldn’t communicate their needs over the course of the day, or by other factors,” said Randy Nelson, co-author of the study and professor of neuroscience and psychology at Ohio State. “But our findings suggest there is a real phenomenon going on here that has a biological basis.” The study appeared in the the Proceedings of the National Academy of Sciences. In the first experiment, researchers compared middle-aged adult mice (7 months old) with aged mice (29 months old) that would resemble humans in their 80s.
Results showed that the aged mice were significantly more active than middle-aged mice in the two to three hours before they would normally go to sleep. “The middle-aged mice had a distinct pattern of activity, with three peaks of activity during their waking hours,” Bedrosian said. “But the aged mice had a flattened rhythm in which they showed the same level of activity throughout their active period.” That means that in the evening, when the middle aged mice would slow down compared to their peak activity levels, the aged mice kept going.