Alzheimer’s and Sleep: Too Little, Too Much and Just Right

Part 1 of a Two-Part Series on Alzheimer’s and Sleep

Dementia can run the gamut in terms of sleep disturbances. From excessive sleep, in often late-stage patients (see further on), to insomnia, Alzheimer’s patients may experience some sort of disordering of their slumber.

What’s Wrong With Not Getting Enough Sleep?

Lack of adequate sleep is correlated with mood disorders such as anxiety and depression. It’s linked with obesity. It’s associated with premature aging – no wonder some call it “beauty rest.” In relation to the present topic, though, I note that not getting enough sack time can also have a pronounced and negative effect on cognitive function.

If it is anything, Alzheimer’s Disease is a condition characterized by suboptimal brain function. It is tempting, therefore, to think that something that, when missing, drives down your cognition will also ramp up your risk of dementia. Contrariwise, if getting plenty of rest helps you to maintain optimal mental functionality, then it is reasonable to think (or hope!) that it might lower your risk of Alzheimer’s.

As I have stated elsewhere, I do not suggest that this is, without exception, a true causal statement. I think of this rather as a bet. Let me put it this way. Personally, I am betting on my health and trying to avoid Alzheimer’s. If I think that there is even the slightest chance that I can stack the deck in my favor by making a little lifestyle tweak, then I will do it! So, if something is correlated with optimal brain function, and the lack of that same thing is correlated with substandard function, then that’s good enough to prompt me to bet on that thing – whatever it is.

And there’s just such a correlation with sleep.[1]

Why Might Sleep Be Important for Dealing With or Avoiding Alzheimer’s?

But the inability to get some restful shuteye can afflict almost anyone. And one concern is that this inability could be a possible dementia risk factor. Still thinking in terms of placing wagers, then, I am interested in treating seriously – and addressing – my own, periodic sleep interruptions.

To put it directly and simply, sleep is important for healthy brain function. It seems to relate especially to how nerve cells communicate.

Despite outward appearances, our brains and bodies are active even when we are sleeping. Recent studies lend credence to the idea that the body repairs, and cleans out toxins from, the brain while we are asleep.[2] Some scientists believe that this “drainage” or elimination system fixes the wear and tear on the brain that due to the stresses of daily living. It supposedly restores our neural command center to peak performance.[3]

The brains of Alzheimer’s sufferers tend to display accretions of amyloid plaques, proteins and other junk. It is intriguing to consider the possibility that these telltale indications of a dementia-plagued brain accumulate, in part, due to something as basic as a breakdown in the sufferer’s power to sleep.

What Is Sleep?

It sounds like a silly question. But, as one recent news headline put it: sleep is a bona fide mystery.[4] Obviously, sleep is more than just lying down and closing your eyes. Some of you can perhaps to relate to the frustrating experience of doing both of those things – maybe for hours on end – without ever actually falling asleep. Delving into the information available on these topics, I read that there are two main “types” of sleep: Non-rapid-eye-movement sleep and rapid-eye-movement sleep. The former is termed non-REM and the latter REM.

Apparently, we go from “deep” sleep into “lighter,” or REM, sleep, in approximately 90-minute cycles. Presumably, each of us may have cycles of varying lengths. Moreover, it may be that an individual’s cycles vary depending on health and other factors. In light of this, the 90-minute interval is probably best thought of as an average. On average, people sleep in cycles of an hour and a half.

The deep-sleep period is, at least according to one prominent sleep theory,[5] supposedly the restorative time. This deeper sleep, however, is claimed to occur more at the beginning of the night[6] than at the end. As the sleeper proceeds from cycle to cycle, REM becomes more frequent and longer-lasting, climaxing in the predawn hours.

Sidebar: Sleep Affects Learning

Since sleep is vital for proper brain function, it is unsurprising (indeed, virtually tautological) that every brain activity is affected by the quantity and quality of sleep that we get.

Consider, for instance, our ability to learn. It seems obvious that dementia sufferers eventually lose this fundamental human power. Yet our capacity for learning is intimately connected to the caliber of our sleep.

On one simple model, the learning process (at least in behavioral terms) may be imagined as consisting of three distinct functions.[7]

1. Acquisition – Or the period during, and process by, which the brain “takes in” some emotion or piece of information. In more computational terms, “acquisition” is a data-input operation.
2. Consolidation – “Consolidation” is a word for the interim stage when the brain converts certain bits of data (emotional, informational, what have you) into long-term, recoverable memories. Thinking along the lines of a computer analogy, perhaps we can say that this second learning function is akin to the act of “saving” data on a hard drive or other storage device.
3. Recall – This is the time at, or means by, which the brain retrieves a piece of stored information or acts upon an associated emotional (or other) state. Crudely carrying forward our PC comparison, we might envision “recall” as an “output” mechanism.

Acquisition and recall are accomplished while we are awake. However, consolidation, which is the somewhat mysterious time when our brain forms ideational and neural connections[8] (some of which we term “long-term memories”), happens while we sleep. (Or so it seems to some researchers.)

Why Does My Alzheimer’s-Affected Relative Sleep So Much?

The thrust of a lot of research on sleep, and certainly a main point of what has been written herein, is that – on average – we need more sleep than we get. It’s easy to think that we should grab as many “winks” as we can.

But a fair number of people who have spent time around Alzheimer’s patients might wonder: Why do many dementia-afflicted persons sleep so much? Why would this be, if sleep is restorative and helpful for maintaining brain function? Would an Alzheimer’s sufferer be chronically sleep-deprived?

Answering these questions presents us with many difficulties. There are several complexities that arise.

Firstly, it is far from obvious that all Alzheimer’s patients do sleep a lot. True, many frequently seem to be asleep. But others – e.g., the so-called “Sundowners” – appear to be awake at all hours of the night.

Secondly, getting restful, restorative sleep involves more than merely reclining with your eyes closed – even if you don’t respond to your name being called. And this exposes another problem: many Alzheimer’s patients are elderly people whose auditory (and other) sensory abilities have dulled. Do grandma or grandpa not react because they are in deep sleep, or because of a lack of awareness that you are trying to communicate? Or is it somewhere in between?

Thirdly, and relatedly, sleep studies[9] (like studies of many other sorts) depend crucially on self-reporting. For example, a person’s nighttime sleep might be monitored and then, upon waking, the person many be asked how rested he or she feels. Thus, the researchers associate being rested or tired with particular patterns of observed sleep behavior (at least partially) on the basis of what the test subject reports.[10]

Once Alzheimer’s is far enough advanced, however, it is apparent that it would be futile to ask the sufferer much of anything, meaningfully. Either the patient’s language capabilities have eroded to a point that makes any verbal communication difficult to impossible, or else the patient’s cognition and memory have decline below the threshold of reliability.

In other words, either the dementia patient can say nothing, or nothing that they say can be accepted at face value. But this bodes ill for the success of any sleep study based on the collection of self-reports.[11]

Despite these difficulties, we may be on at least semi-solid ground if we speculate along the following lines. It certainly seems that some Alzheimer’s sufferers sleep a lot. Several possible explanations are available.

One is that this initial appearance is (at least sometimes) deceptive. Although the dementia-afflicted person might appear to be asleep a lot, this is (again, at least sometimes) not the case. I grant that this suggestion might seem far-fetched at first blush. However, given that we are dealing with often aged individuals whose sensory faculties have diminished and who often revert to childlike (or childish) states of mind, I submit that it cannot be ruled out. If the Alzheimer’s-afflicted person is (at least sometimes) not actually sleeping at all, this would explain why he or she is not getting the restorative benefits of sleep.

But if you don’t care for that possibility, here is another. We have seen that “sleep” is a generic term. There are (at least) two subtypes of “sleep.” Let’s call them deep sleep and shallow sleep. Therefore, even if an Alzheimer’s patient is observed to be “asleep,” it doesn’t follow that the person is cycling from deep to shallow sleep as he or she should. It remains possible that dementia sufferer is “stuck,” as it were, in shallow sleep. This would explain why the person could be observed to be “sleeping” but also why the person is not enjoying the restorative benefits. Restorative benefits only attend to deep sleep, and, for some reason, the Alzheimer’s sufferer only manages to sleep shallowly.

Finally, it must be kept in mind that the brain of an Alzheimer’s patient is basically damaged at a neural-physical level. This damage affects cognition, memory, reasoning, and so on. It is possible, then, that while the restorative process that we sketched above is associated with, or occurs during, deep sleep, it is handled by an isolated or separate “mechanism” within the brain. It may be something like this. The Alzheimer’s sufferer can manage “deep” sleep but, unfortunately, some other neural mechanism is essential for restoration and that mechanism has already been destroyed.

Any of these three suggestion may help explain why some Alzheimer’s patients are, or seem to be, asleep without showing signs of sleep’s purported restorative benefits.[12]

What’s the Right Amount of Sleep?

So, proceeding on the assumption that sleep is both good and restorative, the next obvious question has to do with the amount. This is quite an important question, both for Alzheimer’s sufferers and for anyone who desires to keep his or her body in healthy condition.

We have all heard the proverbial eight-hours-per-day recommendation. And, indeed, this is a good rough-and-ready figure to gauge whether your “hibernation” time is in the ballpark of adequacy.

But…what’s the precise “right” amount of sleep? The answer is: it depends.

It depends on your age. Children require much more sleep than do adults.[13] As we will see in a moment, elderly adults typically get less sleep than younger adults. Whether this is an indicator of a lesser “need” is, however, another question.

The amount of sleep that you need also depends on your health.[14] If you are ailing, you may well need a lot more sleep than you would need if you were healthy. Sleep seems to help our bodies fight infections and recover from illnesses. Moreover, people under stress might require more sleep than they would otherwise. If you’re changing jobs, moving, or going through a divorce, you might catch a few more “Zs” than usual. Likewise, women may sleep more often while pregnant than they do when not pregnant since pregnancy puts inordinate pressures on women’s bodies.

How Much Sleep Does an Alzheimer’s Patient Need?

In general, older adults tend to need between 6 to 8 hours of sleep each night. In general. But these numbers typically assume that we’re talking about older adults with more or less “normal” (for their age) health. When we focus on Alzheimer’s sufferers in specific, we hit another bumpy patch. (Why can’t anything ever be simple?!)

One immediate problem is somewhat indelicate. If John has a cold, we might say: “John, you need more rest.” But that phrase is some what elliptical. To put it another way, “you need more rest” is kind of a shorthand way to tell John that he “needs more rest so that he can get better.” Or again, when Jane is pregnant, we might tell her to go ahead and sleep more. What we mean is usually something like this: “Go ahead and sleep more so that your body can get through this pregnancy and deliver a healthy baby.”

As things currently stand, the first problem, then, is that a person with Alzheimer’s is not going to recover. If Bob suffers from Alzheimer’s and we notice that he’s only sleeping six hours a night, we can’t really say “You need more sleep” in the same way that we did to John and Jane. The clause following the word “so” isn’t curative. After all, the prevailing view is that Alzheimer’s is not like a cold virus that will pass it you just get more rest, eat right, and stay hydrated. Similarly, having Alzheimer’s is not like being pregnant. It’s not a temporary state-of-affairs that puts additional stress on your body, but will be over at a predictable time in the future.

Still, we might think that getting sufficient rest could help Bob (or his caretakers) to better manage his care. Maybe getting more sleep might even improve Bob’s mental clarity to some degree. True, he may never fully recover, but perhaps his decline can be slowed. Thus, there is something that we can put after the “so.” We can say something like, “Bob, you need to get more rest so that you can better cope with your condition.”

Here, we run into the second problem. It’s a practical matter of getting Bob to alter his behavior. If I tell John that he needs more rest, he may or may not agree. He may or may not try to get more rest. But whatever he does, presumably, will be a conscious decision on his part to either ignore or heed my advice. The case is similar with Jane. However she modifies her schedule (or not!) is presumably going to have been her own willful choice. Again, Bob is relevantly different.

Alzheimer’s patients may not be able to comprehend the idea of getting more sleep. It is debatable whether Bob will grasp what we are suggesting to him. Dementia clearly affects the brain’s linguistic abilities. Depending upon the Alzheimer’s stage that he is in, he may not understand part or any of the statement. Even if he does grasp the words, he may be unable to resolve to change his behaviors. For Alzheimer’s also effects a person’s volitional faculties.

Going further, in the case of a person who apprehends and resolves to do what is said, he or she may not remember to follow through with the necessary changes. The most obvious fact about Alzheimer’s is that it severely undercuts memory.

In light of these considerations, we may just have to shrug our shoulders and let Bob sleep as little or as much as he happens to do. The administration of relaxation and sleeping drugs to Alzheimer’s patients arguably has as much (if not more) to do with making the caretaker role more manageable than it does with making the patient more comfortable. It’s a bit of an ethical pickle. If Bob is awake at all hours of the night, is it really “bad” for Bob? Or is it just an inconvenience on his custodian?

It’s not my intention to definitely answer these questions as much as it is just to bring them to the surface. Speaking in broad terms, the human body seems to require between 6-10 hours of sleep, with 8 being the average. Insofar as a person’s nighttime sleep amount is less than 6 hours, it is probably a good bet that encouraging, recommending, suggesting, or otherwise supporting them to get more sleep would benefit their overall health. But for dementia patients, the process of “encouraging,” “recommending,” “suggesting,” and “supporting” might be fraught with practical difficulties or result in outcomes that offset or undermine the hypothetical advantages. The upshot? It might be better to let sleeping patients lie, and let awake patients just roam – focusing, of course, on ensuring that they have a safe environment in which to do so.

But…for those of us who take at least some of these sleep recommendations to heart, or for those early-stage patients who have an interest in enhancing up their own sleep experience, what can be done?

We turn to that question in part 2. See HERE.

Notes:

[1] Numerous online sources highlight diet and sleep as two of the most important health categories to start with for to try to maintain – or improve – your neurological health, both now and in the future. Diet requires its own separate treatment, which you can find here: “Alzheimer’s-Proof Your Diet, Part 1” and “Alzheimer’s-Proof Your Diet, Part 2.”

[2] The National Institutes of Health report that toxins are “flushed” during sleep. See “How Sleep Clears the Brain,” Oct. 28, 2013, <https://www.nih.gov/news-events/nih-research-matters/how-sleep-clears-brain>.

[3] Interestingly enough, I encountered one article that stated sleeping on your side facilitated this drainage and cleansing better than sleeping on your back. On August 4, 2015, Stony Brook University’s online Newsroom posted this suggestion under the heading “Could Body Posture During Sleep Affect How Your Brain Clears Waste?” The article, itself a summary of findings published in the Journal of Neuroscience by researchers Helene Benveniste, Hedok Lee, et al., describes the role of something termed the “glymphatic pathway” – named after the body’s “glial” cells – in “the clearance of amyloid from the brains” under scrutiny. The study, which was performed on mice and is admittedly speculative, nevertheless suggested to investigators that sleeping on your side is superior, for waste-removal purposes, to sleeping on your back or front. For the full report, see: Helene Benveniste, Hedok Lee, Rashid Deane, Tian Feng, Hongyi Kang, Jean Logan, Maiken Nedergaard, Mei Yu, and Lulu Xie, “The Effect of Body Posture on Brain Glymphatic Transport,” Journal of Neuroscience, vol. 35, no. 31, Aug. 5, 2015, pp. 11034-11044; online at <https://doi.org/10.1523/JNEUROSCI.1625-15.2015>.

[4] See Sarah Klein, “The Mystery of Sleep,” Huffington Post, Oct. 27, 2013, updated Dec. 6, 2017, <https://www.huffingtonpost.com/2013/10/27/why-do-we-need-sleep_n_4149438.html>.

[5] Ibid.

[6] I am assuming that we are talking about sleeping at night and being awake during the day. I understand that for some people, due to scheduling demands, this is not the order of events. There is some evidence to suggest that human beings are “made,” so to speak, to be awake during the day and asleep at night. Pursuing this line of thought, you might read that if you go to bed once the nighttime is far advanced, or if you sleep during the day, then you may not be getting much of the sort of sleep that restores your brain and body. Some writers label specific times the “best hours for deep sleep.” One source suggested that this most-advantageous period may be 10 pm to 2 am.

[7] This is all simplistic. It may also be that this particular model is specific to certain branches of psychology. Again, my aim is not to teach a psychological course, but to simply avoid Alzheimer’s. Perhaps the point, then, is this: The brain is important in the learning process, and sleep is important to the brain. Conversely, we might say: Sleep is important in the learning process, and the learning process is important to the brain. I’m just going for intuitive plausibility. I think the statements have that much going for them.

[8] Those in the teaching profession attest to the importance, in improving the retention of newly learned information, of forming “connections.” However, these connections are arguably subsumed under the heading of “acquisition” in our threefold schema. To put it another way, acquisition of information can be enhanced when conscious emphasis is placed upon associations existing among the relevant pieces of information. The operative idea seems to be that these associations, or connections, encourage consolidation.

[9] At least sleep studies involving human beings.

[10] This is overly simplistic. Many studies could be designed to run subjects through various tasks. A subject’s time and accuracy in completing the tasks could then be used to draw conclusions about how rested or alert they are. Still, in Alzheimer’s patients, the nature of the affliction practically guarantees that assigned tasks may be done incorrectly – whether the subject is fully awake and alert, or not.

[11] It is arguable that even studies that utilize brain-scanning technology still bottom out, as it were, with self-reporting. This is more controversially, philosophically. But one attractive picture is that brain states and mental states “come apart.” A neurologist plausibly has direct access to your brain states – via imagining and scanning equipment. So, suppose that Dr. Alpha scans Miss Omega and observes that Region 1 of Miss Omega’s brain displays marked neural activity. Still, Dr. Alpha has only one way to know what is going on in Miss Omega’s private, mental state. He must ask her.

[12] Of course, there is a also the possibility that sleep doesn’t have restorative benefits. But this flies in the face of the empirical evidence surveyed above.

[13] Newborns may sleep upwards of 15 hours a day. This declines a bit to around 12 hours per day when children become toddlers. Even older children and teenagers might require between 9 and 11 hours of slumber every night.

[14] It is worth noting, at least for people who get into or believe in “biorhythms,” is worth noting that a person’s placement on the various (allegedly) cycles (e.g., physical, emotional, intellectual)