“Sundowning” and sleep disorders in people with Alzheimer’s disease

 

SEPTEMBER IS WORLD ALZHEIMER’S MONTH.

The Centers for Disease Control and Prevention (CDC; Atlanta, GA) estimates that 5.8 million Americans have Alzheimer’s disease. People with Alzheimer’s disease frequently have sleep problems. A phenomenon that can be impacted by sleep problems in a loved one with Alzheimer’s disease is “sundowning.” A loved one experiencing sundowning begins to become restless (e.g., walking around aimlessly, rocking, pacing), belligerent (e.g., striking out at caregivers), confused, disoriented (e.g., cannot find his/her bedroom), or depressed in the early to late evening (i.e., when the sun is going down; hence, “sundowning”). These changes can last for hours or all night. The next day, the person is back to “normal”—until evening, when symptoms of sundowning return.

Why sundowning occurs is not fully clear. However, many people with dementia have advanced-sleep phase syndrome (ASPS) or delayed sleep- phase syndrome (DSPS). People with ASPS naturally want to go to bed early (e.g., 7:00 p.m.) and awaken early (e.g., 3:00 a.m.), whereas people with DSPS naturally want to go to bed late (e.g., 3:00 a.m.) and awaken late (e.g., 11:00 a.m.). If caregivers attempt to keep a loved one with ASPS awake in the evening with the hope he/she will sleep all night, the loved one may become belligerent because of the frustration at being prevented from going to sleep. If caregivers attempt to put a loved one with DSPS to bed at a “normal” time, he/she may become agitated, feeling forced to go to bed when not tired.

Some research indicates that bright light therapy can be helpful in shifting sleep/wake times to a later or earlier time in people with Alzheimer’s disease. Bright light therapy involves exposing a person to strong-intensity light for a short period (e.g., 30-90 minutes) in the evening before going to bed to shift the sleep phase to a later time (for people with ASPS) or in the morning soon after awakening to shift the sleep phase to an earlier time (for people with DSPS). However, using bright light therapy should be done under a physician’s care since applying it at the wrong time may create more problems with a loved one’s sleep-wake schedule.

Sundowning in some people with Alzheimer’s disease may be related to an undiagnosed sleep disorder such as restless leg syndrome or sleep apnea. People with restless leg syndrome begin to feel creepy, crawly, uncomfortable sensations in their legs in the evening. In the daytime, the symptoms do not occur. To relieve the sensations, a person may walk, pace, or repeatedly scratch or rub the legs. A person with Alzheimer’s disease may be unable to describe these sensations to a caretaker and thus begin to walk or pace restlessly in the evening to relieve them. Sleep apnea, a disorder in which a person stops breathing intermittently during sleep, causes frequent arousals from sleep, which can contribute to excessive sleepiness that worsens as the day progresses. Excessive sleepiness can manifest as confusion and mood changes (e.g., depression) noted in sundowning.

If your loved one has Alzheimer’s disease and experiences sundowning, you may want to consider having a sleep study done to determine whether an undiagnosed sleep disorder such as restless leg syndrome, ASPS, DSPS, or sleep apnea may be a contributing factor. Treating an underlying sleep disorder may improve sundowning in your loved one.

Regina Patrick, RPSGT, RST, is a freelance writer/editor and a registered sleep technologist. She has been involved in the sleep field for more than 30 years.

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