Alzheimer's disease and light therapy

Alzheimer's disease is the most common type of dementia, accounting for around half of all cases, and affects about 450,000 people in the UK.

The disease affects the structure of brain fibres, causing 'tangles' and hardening that disrupts the transmission of impulses between brain cells.

It's still unclear what causes Alzheimer's disease but it is possible to make life easier for the individual - and their carers - by treating some of the symptoms.

Symptoms

Alzheimer's is a progressive disease, which means that gradually, more and more parts of the brain are damaged and symptoms become more severe.

Lapses of memory, problems finding the right words.
Become confused, even forgetting the names of family members and other familiar people and places.
Experience mood swings. They may become aggressive or agitatedfeel sad or angry. They may feel scared and frustrated by their increasing memory loss.
Become more withdrawn, partly because it becomes difficult to communicate and also because they lose confidence.
Loss of mobility, clumsiness, they may begin to shuffle rather than walk.

Eventually individuals will require round-the-clock support and help with all their daily activities.

What is sundowning?

Sundowning is one of the symptoms more common in advanced cases of Alzheimers', possibly because the disease begins to affect the parts of the brain that control the circadian rhythms, the body clock and the sleep-wake cycle.

People with Alzheimer's disease (and many other forms of dementia) are often at their best early in the day. Sundowning is the term used to describe the increased agitation and confusion that typically occurs in the late afternoon and evening and sufferers are often found up and about in the middle of the night.

How light therapy can help

The combination of damaged nerve pathways caused by Alzheimer's disease and normal deterioration of the eyes due to ageing, means that levels of light (especially indoors) are not usually sufficient to signal that it is daytime. If the internal body clock is not tuned in to the usual daily pattern, this affects not only the wake-up process but also the activity and sleep cycles that come into force in the evening.

There are a growing number of studies to show that better and brighter lighting can help improve sundowning behaviour and reduce sleep/wake disturbances, particularly in the most severe cases. Morning sessions in front of a bright light can be particularly effective e.g. using 2,500lux lights for an hour or so and improving overall lighting conditions also had positive effects.

There is also some evidence to show that dawn/dusk simulation can be helpful in re-aligning the body clock to promote a better sleep/activity cycle.

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Comments on this article

Carl Otto
joined 21 Oct 2007
2 posts

Posted by Carl Otto, 10:06 21 October 2007

Interesting, I didn't know much about the light therapy for Alzheimers treatment before I stumbled on this post. I've read up on it and found a lot of evidence to support exactly what you say.
For anyone else interested in the subject of light therapy / Alzheimers disease, here are a few of the links I found:
Article in Sleepreview
Medicinal News Today article by Leslie H Lang
Sage Journals (need to register here)
Alzimers and light therapy, some info here
Paranoid delusions and hallucinations and bright light therapy in Alzheimer's disease

Carl Otto
joined 21 Oct 2007
2 posts