Alzheimer's Disease: Understanding Sundowning Syndrome
In previous articles, I have discussed challenging behaviors in Alzheimer's disease, such as wandering, that cause families distress and result in the patient being institutionalized and in this article I will address Sundowning syndrome, a behavior concerning disruption of the sleep-wake cycle, one that results in increased confusion, restlessness, agitation, and anxiety—especially after dusk—and may continue throughout the night. It has been documented to occur in 20 percent of all patients with Alzheimer's disease, and has been appropriately named sundowning as it coincides with "the sun going down."1 Sundowning syndrome is also known as Sundowner's syndrome. Sundowning can be especially difficult for caregivers as it is, in effect, wandering after dark.
When Does Sundowning Occur?
When I refer to the sleep-wake cycle, I am referring to a patient's circadian rhythm. Circadian rhythmicity is what regulates all of our bodily processes, including body temperature, secretion of hormones, heart rate, and so on, and is controlled by the brain. We see behavioral changes in these patients because Alzheimer's disease causes damage to the brain resulting in brain cell death, and shrinkage of the organ. Most of the behavioral issues concerning this dementia are caused by ongoing changes in the brain (see the FAST scale, which identifies loss of function). We tend to see sundowning in the Moderately Severe or Mid-stage of this disease, which we call Stage 6 (there are seven distinct stages of Alzheimer's disease). Sundowning syndrome occurs while the patient is still ambulatory. While this behavior is challenging for families and staff, the good news is it tends to peak in this stage and then diminish as Alzheimer's progresses.
