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Interrupted Sleep And Memory Loss

Remember the last time you forgot something? Did you forget about the last time this happened? Chances are, you were probably sleep deprived.

There are tons of studies showing that even mild sleep deprivation can have detrimental effects on memory and executive functioning. Now there’s new research from Stanford University showing that sleep fragmentation can be just as detrimental as sleep deprivation. The researchers figured out a way of fragmenting sleep in mice without causing any stress, using special lights to control genetically engineered brain neurons that control sleep and wake. By pulsing these cells with 10 second bursts of light, they could fragment sleep without significantly altering the quality and the composition of sleep, or the total sleep time.

Their conclusion was that “regardless of the total amount of sleep, a minimal unit of uninterrupted sleep is crucial for memory consolidation.”

Another research tool that’s used to measure deep sleep instability is what’s called cyclic alternating pattern (CAP) analysis. Cyclic patterns of brief brain wave arousals were found to be more common in people with upper airway resistance syndrome (UARS) and fibromyalgia.

These studies support the general observation that people with people with UARS, fibromyalgia, or idiopathic hypersomnias have increased levels of subtle arousals that don’t get scored on a routine sleep studies.

 

 

The Stroke Belt: Memory Loss From Sleep Apnea?

It’s already been shown that stroke and sleep apnea can go hand in hand: Untreated obstructive sleep apnea increases your chances of having a stroke by 2-3 times normal. Having a stroke can also increase your chances of developing or worsening sleep apnea. I’ve stated in the past that a stroke doesn’t happen all of a sudden—it’s the end result of a cumulative series of events that leads to a major brain artery blockage or hemorrhage. But even before this major stroke occurs, there’s already some degree of very mild or minor small vessel damage. Studies have shown that untreated sleep apnea patients have multiple area of damaged brian tissue, especially in areas that control memory, executive function and autonomic control. Other studies show numerous small microscopic strokes that are detectible on CT or MRI scans.

A recent article in the New York Times described an increased association between stroke and memory loss in people who live in the stroke belt (deep south). The researchers mention possible underlying risk factors, including hypertension, diabetes, high cholesterol, and obesity. Not surprisingly, they don’t mention obstructive sleep apnea at all. Yes, a good diet and regular exercise are important to address, but not treating obstructive sleep apnea is a recipe for failure. Not getting efficient sleep promotes weight gain, so it’s going to be a struggle to lose weight, no matter how healthy you eat or how much you exercise.

Brain Regeneration After CPAP Use for Sleep Apnea

I’ve written numerous times in the past about how various areas of the brain can be injured from untreated obstructive sleep apnea. Studies have shown that sleep apnea patients have lowered brain density levels in areas that control memory, executive function, and autonomic control. Despite all the bad news about the effects of untreated obstructive sleep apnea on the brain, here’s some good news: A recent study showed that the brain can regenerate even after 3 months of CPAP usage. Brain volume actually increased significantly, and neuropsychological tests improved significantly as well. The only caveat was that this study was supported by the Respironics Foundation (not that there’s anything wrong with that).

Did My Father Die From Sleep Apnea?

My father died a few months ago from metastatic prostate cancer. Looking back on the series of events that occurred before his death, I’m wondering if it was really from Alzheimer’s Disease aggravated by sleep apnea. Let me explain…

About 4 weeks before his death, my father was a vibrant and young 78. He took classes with undergraduates at Hunter College, performed in a musical theater group, sang in his church choir, played tennis, swam, and and went hiking up a mountain every week. He was originally diagnosed with prostate cancer over 10 years ago, but was in remission until recently, when it finally surfaced in his lower spine. He underwent radiation therapy, which was an ordeal for him, but he managed to fight through it.

One day, we got a call from the hospital ER saying that my father was admitted after begin found unconscious on the sidewalk. A CT of the brain was reported as being normal. Before this, he was completely coherent, and mentally very sharp. After this hospital admission, he kept going in and out, not being able to express himself, and not even remembering who his children were. Over the next 2 weeks, his condition deteriorated even further, and eventually passed away in a wonderful hospice, Calvary Hospital.

During his last few days, he would sometimes talk as if he were a 5 or 6 year old. He even stopped recognizing his family members. During these last two weeks, although not official, he had classic symptoms of Alzheimer’s-like dementia.

I’ve also always suspected that he had an undiagnosed sleep-breathing problem, with very loud breathing and an open mouth during sleep. We know that untreated obstructive sleep apnea can thicken your blood, making it much more viscous, and more likely to stagnate and clot. Sleep apnea patients have increased inflammatory markers such as TNF, IL-2, IL-6, and many others. Cancer is also thought to cause a hypercoagulable state. He also has two other risk factors for sleep apnea: older age and having an Asian facial structure.

Something must have happened that day when my father was walking down the street. He must have clotted or damaged a critical part of his brain that’s responsible for short term memory and face recognition. Whatever happened, it wasn’t large enough to show up on his head CT.

It’s been shown that untreated obstructive sleep apnea can cause brain damage in many different ways. This includes multiple mini-strokes throughout the brain, and lowered gray matter density in parts of the brain that includes memory, executive function, and autonomic nervous system control.

I’m convinced that all modern human’s inability to breathe properly as we get older is a major factor in how quickly we age or develop illnesses. Many of the chronic medical complications or conditions that we die from can be shown to be directly or indirectly related to sleep-breathing problems.

Lou Gehrig, Head Trauma, & Sleep Apnea

A recent study showed that head trauma can sometimes mimic Lou Gehrg’s disease (or amyotrophic lateral sclerosis – AML). This condition was named after the famous New York Yankees baseball player that develop muscle weakness, paralysis and eventually, death. The journalist displayed a vintage photo of Gehrig just after being knocked unconscious by a runaway pitch.

Knowing what we know about the effects of untreated obstructive sleep apnea, you could say that any type of brain injury, whether due to blunt head trauma, or small to large vascular events, cannot be good for memory, breathing, executive function, and motor control. But these are the same areas that are known to be affected when someone has untreated obstructive sleep apnea.

Chronic hypoxia causes inflammation and clotting in small vessels. One study showed that sleep apnea patients have much thicker blood, and that ear-brain reflexes where diminished, but improved after treatment. Hypoxic conditions in mice have been even shown to produce amyloid plaques—the same thing that’s seen in Alzheimer’s disease.

We also know that sleep apnea patients have much higher number of lacunar infarcts than people without, as well as having anywhere from 3-5 times increased risk of stroke. I would think numerous small strokes added together over years could lead to at least some degree of brain dysfunction.

It’s also safe to assume that if you have head trauma, having obstructive sleep apnea can prevent proper healing and regeneration.

Given all this, isn’t it possible that when a certain part of the brain is “injured” due to obstructive sleep apnea, depending on where it occurs, you’ll get various symptoms that correspond to where it’s happening? For example, we know that in sleep apnea patients, brain density, volume and metabolism are significantly diminished in areas that control breathing, respiration and autonomic control. What if you clotted a small vessel that feeds this area? Could it lead to central sleep apnea? What if you damage areas that produce dopamine, or hypocretin? Could this process lead to symptoms that mimic Parkinson’s or even narcolepsy? What if you had fluctuating areas of diminished blood flow that returns to normal? Could this lead to symptoms that are similar to multiple sclerosis?

I realize that much of this may be a stretch, but it never ceases to amaze me how devastating obstructive sleep apnea can be to the brain, no matter how mild it may be.

What do you think about my theory? Is it plausible, or too far fetched of an idea? I’d like to hear your opinions about this.

More Links Between Sleep Apnea & Alzheimer’s Disease

A patient happened to comment that her husband has Alzheimer's disease, and also has severe sleep apnea. She notices that for years, he stops breathing repeatedly at night, with multiple gasps for air and frequent awakenings. Unfortunately, he's not able to tolerate his CPAP machine. She's convinced that her husband's worsening brain function is aggravated, if not caused by his untreated sleep apnea. 

She's brought up this issue with numerous prominent Alzheimer's doctors and is usually told that there's no connection, and her idea is blown off. 

Knowing what we already know about sleep apnea and brain damage, I totally agree with her. Numerous studies have shown significant brain damage in multiple parts of the brain from untreated sleep apnea, including tissue volume loss, tissue density loss, lacunar infarcts, and decreased metabolism in critical areas of the brain. One recent study showed that CPAP therapy significantly increases brain gray matter volume after 3 months of usage. Executive functioning and short term memory were also significantly improved.

Should there be more research into the association between sleep apnea and Alzheimer's? What do you think?

Is Your Father Going Through Menopause?

Over the past year, ever since the birth of our third son, Brennan, I've been more tired than usual. Not too unexpected when you have a newborn, right? Add to this having to help my wife tend to the needs of our two older boys, who are 7 and 10. But even now when Brennan is sleeping well through the night, and I'm sleeping about 7 hours every night, I'm still more tired than I used to be, despite running 3 times per week, and being as fit as ever. Could I be going through male menopause?

The Facts of Male Menopause

I wrote last month about how mothers can suffer from poor sleep due to the effects of menopause on sleep quality, but what about fathers? You may have heard about male menopause, or more precisely, andropause. It's not that well known, and even if it happens, it's so slow and insidious that most men don't realize it's happening.

Well, it turns out that men go through a similar transition during the mid-life years. Not only does testosterone slowly drop, but thyroid levels as well. Our traditional medical culture and even holistic and alternative doctors sometimes argue that aging is a deficiency of certain hormones, vitamins or minerals, and that replacement using synthetic or natural supplements is the answer. But is  that the only answer?

Most people think that this is a natural part of aging, along with the typical memory loss, balding, wrinkles and lowered energy and stamina. But what if I told you that I routinely see even young to middle aged men who complain about hot flashes, night sweats, mood swings, insomnia and irritability—or all the prevailing symptoms of menopause?

Aging As A Consequence of Poor Sleep

In my book, Sleep, Interrupted, I describe a sleep-breathing paradigm where all modern humans are on a continuum, where we're all susceptible to sleep-breathing problems to various degrees.

As you age, it's expected that overall, you'll keep moving up this continuum to the point where sleep breathing problems become much more serious as in obstructive sleep apnea. Not only do we sag and bulge on the outside as we get older, it also happens on the inside, including your upper airway. And as your airway becomes narrower, the more trouble you'll have breathing while sleeping, and this in turn will make you wake up more and obstruct more.

Women experience more dramatic changes in hormone levels (particularly progesterone) that affect upper airway patency, but levels of testosterone and even small amounts of progesterone can also influence upper airway muscle tone in men as well; Not to mention the typical weight gain that occurs in the middle years, leading to even more narrowing of the upper airway. Adding any degree of inflammation to the upper airway (such as from a cold, allergies, or reflux) can cause more frequent obstructions and arousals. Poor sleep efficiency leads to weight gain, and weight gain narrows the throat.

Sleep Apnea And Aging

It's a given that as you age, your upper airway begins to narrow gradually, aggravated intermittently with additional narrowing from inflammation. This is also why men begin to develop cardiovascular disease as they get older. Women are somewhat protected before menopause, but afterwards, they begin to catch up when it comes to rates of heart disease. As you slowly move up the sleep-breathing continuum, your risk of developing obstructive sleep apnea increases, and once it begins, a vicious cycle begins, where poor sleep aggravates weight gain, and weight gain aggravates poor sleep.

Poor sleep (by causing a physiologic form of stress) also causes major hormonal changes by lowering your thyroid levels, as well as your reproductive hormones. So naturally, if you test for thyroid or testosterone levels, it may come back on the low side. Not too unexpectedly, supplementing with replacement hormones helps in some cases, but not all the time.

We know that untreated obstructive sleep apnea (OSA) can aggravate or cause routine medical conditions such as diabetes, high blood pressure, depression/anxiety, heart disease, heart attack and stroke. Your risk of car accidents also increases anywhere from 3 to 10 times normal if you have OSA. Add to this all the other common expected conditions that you may experience as you get older: frequent bathroom trips, balding, erectile dysfunction, hearing loss, and even Alzheimer's.

Taken at face value these seemingly disparate symptoms of old age aren’t all that unexpected. However, if you look at them from the perspective of my sleep breathing paradigm, you’ll begin to see how it’s your breathing and not necessarily your age that’s making you feel sick and tired.

Too Many Bathroom Trip—Risky For Your Health

It's been shown that going to the bathroom frequently at night is not because you're making too much urine, but because you stop breathing and you think you have to go to the bathroom. One recent study showed that going to the bathroom two or more times per night increases your chances of dying by 50%. There have even been many anecdotal reports of hair regrowth after definitive treatment for sleep apnea. Erectile dysfunction (ED) is a very well-known complication of sleep apnea. Having ED can predict the presence of sleep apnea in the majority of patients.

Brain Damage From Poor Breathing While Asleep

Untreated sleep apnea also increases your chances of microscopic strokes and small vessel blockages in multiple, critical areas of the brain. One recent study showed that sleep apnea patients have 20% smaller brain volume in the Mammary bodies. Another showed smaller brain tissue densities in critical areas of the brain that controls memory, executive function, breathing and respiration. Untreated sleep apnea patients have much more viscous (thick) blood that can stagnate and clot in small vessels in the brain. One area that's particularly sensitive are the small vessels that supply the high-frequency sensing areas of the inner ear.

All these issues begin when you're young, but begin to manifest in your middle years, progressing to full-blown medical complications when you reach your 60’s and 70’s. As you can see, how narrow you upper breathing passageways are determines how quickly you age or how often you become sick. Now that I'm in my mid-40s, if I don't get at least 7 hours of sleep, or if I eat later than usual, I definitely feel worse the next day. This is why it's important to do everything possible to breathe well at night while sleeping, in addition to a healthy lifestyle that includes a good diet, regular exercise and smart decisions when it comes to your sleep.

Sleep Apnea Causes Brain Damage

A new study in the journal Sleep revealed that using special MRI imaging techniques, untreated sleep apnea patients have significantly decreased concentrations of gray matter in certain predictable areas of the brain. This means that the density of neurons is much lower than normal. The average AHI was 52, and on initial inspection of the MRI, there were no obvious structural abnormalities, with no differences in the total volume. However, gray matter density was significantly lower for sleep apnea patients in various areas of the brain that serves important functions such as memory, breathing, cardiovascular function, and autonomic function.

This study complements a prior study that showed that OSA patients have multiple dysfunctional areas of the brain.

I think the implications of this study along with various other similar studies are profound. What this means is that if you have obstructive sleep apnea, you can literally kill off certain parts of  your brain, that preferentially control your memory, executive function, your breathing patterns, and even your your heart rate. Could this be an alternate explanation for central sleep apnea? Maybe this is also why not all patients that use CPAP feel significantly better—perhaps the damage is irreversible. What's frightening is that you can suffer permanent brain damage long before your sleep apnea is even picked up and treated. 

Take a look at the abstract and read the paper if possible. What do you think about these findings? Please enter your opinions in the text box below.

Sleep Apnea Can Cause Brain Damage

A recent review of the literature in the Journal of the American Dental Association concluded that episodes of hypoxia (low oxygen levels) due to sleep-breathing problems can lead to permanent brain damage, and can even occur in early childhood. These findings are not too surprising, with a number of studies in recent years that support this finding. What’s troubling, however, is that no one is making the possible connection between brain injury due to sleep apnea and other well known neurologic conditions such as ADHD and Alzheimer’s.

Numerous studies have shown that sleep apnea patients have more areas of injured or dead brain tissue than patients without sleep apnea. This can occur in the gray and white matter (which serve memory and cognition), and even in the lower areas that control breathing, sensation and movement. One sleep researcher at a meeting that I went to many years ago stated that in young children who undergo tonsillectomies for obstructive sleep apnea, they catch up pretty dramatically in terms of cognition, memory, reaction times and intelligence scores. But they never catch up fully with age matched control children that don’t have obstructive sleep apnea. What this implies is that there may be a slight, but permanent brain injury.

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