Poor Sleep and Alzheimer’s Disease

I’ve decided to offer classes in using hypnosis to get better sleep–the first is scheduled for March 24 at 10 am. It’s nearly full, so I’ve scheduled a second on April 21, also at 10 am. If you’re interested, contact me, and I’ll send you the details.

Today’s post is about just one of many reasons this topic concerns me.

An article by sleep scientist Matthew Walker* in the October 2017 issue of New Scientist describes a mechanism through which Alzheimer’s disease disrupts memory consolidation—and the mechanism has to do with the poor sleep experienced by people with the disease. The cause itself is not clear, but the connection is clearly established, and it’s a compelling reason for us to address any poor sleep habits we may have.

The connection has to do with the effect of the buildup of toxic amyloid proteins characteristic in the disease, which over time reduces the amount of NREM (non-rapid eye movement) slow wave sleep we typically get during the night. And although it’s common to get less NREM sleep as we age, normal aging doesn’t usually affect the slow wave sleep we get.

Slow wave sleep is responsible for saved memories; in other words it’s involved in the process of shifting memories from short-term to long-term storage. The research shows that more toxic amyloid buildup is correlated with more disruption of slow wave sleep, and more loss of memory consolidation.

It turns out that the area of the brain that is predominantly affected by the disease is the frontal lobe, which is also the part of the brain that is responsible for starting our slow wave sleep phases. The research has confirmed that it’s not just a coincidence that people with Alzheimer’s disease have poor sleep—their poor sleep is qualitatively different from normal sleep changes associated with healthy aging.

Here’s a weird bit of the Alzheimer’s puzzle: how do the toxic plaques cause memory loss?

It’s puzzling because even though amyloid deposits only accumulate in some parts of the brain, they don’t accumulate in the areas of the brain associated with memory. So what is the connection between the disease and memory loss?

It took a sleep scientist to come up with an answer. Here’s his theory, in his own words:

We already knew that in young healthy adults, the slow brainwaves of deep NREM sleep effectively hit the “save” button on new memories, helping us retain what we have recently learned. Sleep also helps us access and thus remember past experiences.

If amyloid was blocking deep NREM sleep in Alzheimer’s disease, then perhaps this loss of youthful deep sleep prevents older adults from being able to save new memories and hold on to experiences past?

He designed a study to test this theory, giving patients new information at night and then testing their recollection the next morning, after monitoring their sleep. The results? Patients with more amyloid deposits in the middle frontal regions of the brain had the most severe loss of deep sleep, and they were unable to remember the new material.

The connection is there—disrupted deep NREM sleep is the missing link between amyloid and memory loss. So far, studies of older adults with sleep disorders confirat treating sleep problems slows the onset of Alzheimer’s Disease by up to 10 years.

Again, although the research does not show a causal relationship between poor sleep and Alzheimer’s disease, clearly getting better sleep now can reduce our risk significantly. And further, since the symptoms so disrupt quality of life, it makes sense to me that we choose to do whatever we can to protect our sleep, and our memory.

By the way, the studies also showed that just as prescription medications for sleep do not work beyond a small placebo effect in helping people fall asleep, they do nothing to mitigate the loss of slow wave sleep.

Sleep well tonight. Do contact me if you’re interested in exploring hypnosis to help you get healthy sleep, either one-on-one, or as part of a group.

* This post is a summary of part of Dr. Walker’s article, and any errors are mine.  Do check out his article–he’s a good writer.

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