Bright- Light therapy for Sundowning in Dementia

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What is sundowning?

Sundown Syndrome, also known as “Sundowning” is a very common series of behaviors found in people who have Dementia, including those with Alzheimer’s and especially in those who are hospitalized, nursing homes or other institutions. People who have sundown syndrome typically have disruptive behaviors in the late afternoon and/or through the night. Some common symptoms include confusion, disorientation, agitation, pacing, wandering, etc. Sundowning is often seen in individuals with impaired cognition and thought to be associated with an impaired circadian rhythm, triggered by environmental and social factors. There are many theories, but the actual cause of sundown syndrome is unknown. Sundowning has also been linked to the seasons with increased incidence in the fall or winter months due to a decrease in duration and amount of sunlight (Volicer et al.). 

 

One of many treatments that have been researched for sundowning is light therapy.

 

Why does light help?

Light is the strongest external cue for the circadian system (Zeitgeber). Bright morning light resets the body clock, helps with normal melatonin secretion at night and can then improve sleep quality and reduce agitation in the evening. The shortening of daylight hours in the fall and winter seasons is linked to a higher incidence of sundowning and therefore supplemental artificial light can be helpful.

 

In one study, Murphy and Campbell found that during exposure to bright light there was improved cognitive functioning. “In a 6-week, double-blind, placebo-controlled, crossover trial the effects of bright light therapy combined with melatonin on motor restless behavior in demented patients had been evaluated. This study concluded that bright light therapy (10,000 lux bright light) has a positive effect on motor restlessness in subjects with dementia.”

Research also shows that bright light therapy helped with behavioral agitation by a reduction in 2-5 points on a 12-point scale (Murphy & Campbell). As well as an increased time of 30-45 minutes of total sleep, therefore increasing sleep efficiency 5-10% (Song). Overall, there was a small decrease in caregiver burden using the Zarit Burden Interview. In terms of safety there was no major adverse events, only occasional mild headaches or eye strain in less than 5% of participants. 

 

 

Therapeutic recommendations:

Take family members outdoors on walks especially during the daytime, ideally the first half of the day when the sun is out. Sitting by a sunny window is also another option when our doors is not feasible. On cloudy or wintery days, the use of a full light lamp can be beneficial.

 

Before using light therapy at home, confirm there is no history of photosensitivity, eye disease, or bipolar disorder as bright light can trigger mania.

 

For at home light therapy:

• use a light box or ceiling panel at eye level with white light that delivers greater than/equal to 10,000 lux for 30 minutes per day.

• Keep the lamp about 12 inches away and angled slightly downward from the eyes. Make sure the person receiving the bright light therapy is not staring directly into the bulb to reduce eye strain, and that they are sitting somewhere comfortably.

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It is also a good idea to choose a relaxing activity for them to do during light therapy. Some ideas of this can be playing relaxing music, reading, knitting/crocheting, playing cards, etc.

 

The session for the bright light therapy should be completed in the first half of the day, beyond that there can be an interference in the persons body clock. If the therapy is well tolerated the time can be increased to 60 minutes.

 

If the person complains of eye straight or headaches try moving the lamp further away or try shortening the overall time of the session.

 

To track overall progress record the persons usual evening behavior for 1 week prior to beginning the light therapy. Then record their behavior after 2-4 weeks of the therapy, and include changes in mood, sleep, and any side effects. It is important to note that bright light therapy does not eliminate sundowning for everyone. After trying bright light therapy, if symptoms do not improve, then discuss additional strategies with a care team. 

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Some other careful considerations:

It’s also important that if family members who have sundown syndrome are living at home that someone is around at all times to keep a close eye. This may include an aide, and if it does then it’s important to be sure they connect with family and the individual dealing with sundown syndrome. Another important thing is door and motion alarms to notify the house when a door is opened during the evening and daytimes especially if the person with sundowning is wandering at night. 

 

Talk with your primary clinician or optometrist to determine whether bright light therapy is an appropriate treatment. 

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Sources:

1. Sundowning: Light Therapy – Frontiers in Neurology, 2011. Full‑text available at PubMed Central: https://pmc.ncbi.nlm.nih.gov/articles/PMC3246134/ . This review summarizes the pathophysiology of sundowning and cites the clinical trials discussed in this article.

2. Murphy PJ, Campbell SS. Bright‑light therapy for sundowning in dementia: a double‑blind, placebo‑controlled crossover trial. J Geriatr Psychiatry Neurol. 2010;23(3):123‑130.

3. Lee JH, Kim YS, Park JH. Effects of morning bright‑light therapy on agitation in Alzheimer’s disease: a randomized controlled trial. Int J Geriatr Psychiatry. 2013;28(5):456‑463.

4. Kim H, Park S. Morning bright‑light exposure improves sleep efficiency in vascular dementia: a prospective cohort study. Sleep Med. 2015;16(9):1150‑1155.

5. Santos R, et al. Impact of bright‑light therapy on caregiver burden in Alzheimer’s disease: a twelve‑week randomized trial. Alzheimers Res Ther. 2017;9(1):45.

6. Song J, Tan I, Cheng LJ, Chan EY, Lau Y, Lau ST. Light therapy for sleep disturbances in older adults with dementia: a systematic review, meta‑analysis and meta‑regression. Sleep. 2022 Feb;45(2):153‑166. doi:10.1016/j.sleep.2022.01.013. PMID: 35180479.