Sleep. It’s something we spend about a third of our lives doing, but do we really understand what it’s all about?
Recent research may shed new light on this question. We’ve found that sleep may actually be a kind of elegant design solution to some of the brain’s most basic needs, a unique way that the brain meets the high demands and the narrow margins that set it apart from all the other organs of the body.
The first problem that every organ must solve is a continuous supply of nutrients to fuel all those cells of the body. In the brain, that is especially critical; its intense electrical activity uses up a quarter of the body’s entire energy supply, even though the brain accounts for only about two percent of the body’s mass. So the circulatory system solves the nutrient delivery problem by sending blood vessels to supply nutrients and oxygen to every corner of our body. The blood vessels form a complex network that fills the volume. They start at the surface of the brain, and then they dive down into the tissue itself, and as they spread out, they supply nutrients and oxygen to each and every cell in the entire brain.
Just as every cell requires nutrients to fuel it, every cell also produces waste as a byproduct, and the clearance of that waste is the second basic problem that each organ has to solve. The body’s lymphatic system has evolved to meet this need. It’s a second parallel network of vessels that extends throughout the body. It takes up proteins and other waste from the spaces between the cells, it collects them, and then dumps them into the blood so they can be disposed of. But there are no lymphatic vessels in the brain!
The brain’s solution to the problem of waste clearance was ingenious. The brain has this large pool of clean, clear fluid called cerebrospinal fluid. The CSF fills the space that surrounds the brain, and wastes from inside the brain make their way out to the CSF, which gets dumped, along with the waste, into the blood. So in that way, it sounds a lot like the lymphatic system? But what’s interesting is that the fluid and the waste from inside the brain don’t just percolate their way randomly out to these pools of CSF. Instead, there is a specialized network of plumbing that organizes and facilitates this process. The CSF on the outside of the brain doesn’t stay on the outside. Instead, the CSF was pumped back into and through the brain along the outsides of the blood vessels, and as it flushed down into the brain along the outsides of these vessels, it was actually helping to clear away, to clean the waste from the spaces between the brain’s cells. This is a solution that is entirely unique to the brain.
But the most surprising finding was that with all this fluid rushing through the brain, it’s see is that when the brain goes to sleep, the brain cells themselves seem to shrink, opening up spaces in between them, allowing fluid to rush through and allowing waste to be cleared out. When the brain is awake and is at its most busy, it puts off clearing away the waste from the spaces between its cells until later, and then, when it goes to sleep and doesn’t have to be as busy, it shifts into a kind of cleaning mode to clear away the waste from the spaces between its cells, the waste that’s accumulated throughout the day.
The waste product that these recent studies focused most on is amyloid-beta, which is a protein that’s made in the brain. So we measured how fast amyloid-beta is cleared from the brain when it’s awake versus when it’s asleep. We found the clearance of amyloid-beta is much more rapid from the sleeping brain.
A series of recent clinical studies suggest that the failure of the brain to keep its house clean by clearing away waste like amyloid-beta may contribute to the development of conditions like Alzheimer’s.
So what this new research tells us, then, is that the one thing that all of you already knew about sleep is that it refreshes and clears the mind.
This may actually be a big part of what sleep is all about. While our body is still and our mind is off walking in dreams somewhere, the elegant machinery of the brain is quietly hard at work cleaning and maintaining this unimaginably complex machine. In the brain, the consequences of failing to clean house may be the very health and function of the mind.
NEW TREATMENT FOR OSA IN WOMEN
by Alison Wimms, ResMed
Women make up nearly 40 percent of patients newly diagnosed with obstructive sleep apnea, but there has never been a treatment specifically designed to treat female characteristics of sleepdisordered breathing. ResMed has now introduced “AirSense™ 10 AutoSet for Her” providing more effective treatment to women with mild to moderate OSA at lower, comfortable pressures. How it works:
Women with OSA have significantly different sleep than men. Women tend to take longer to fall asleep than men. Women also have fewer apneas than men, specifically fewer full obstructive apneas meaning their upper airways don’t collapse as often. However, they do have more flow limitation which means the upper airway narrows and less air enters the lungs. Women also tend to have clusters of events during REM (dream stage) sleep. All of these aspects of sleep apnea can cause arousal and disrupted sleep. This can lead to symptoms such as insomnia, fatigue, reduced daytime cognitive function, headaches and depression.
The “for Her” was designed to treat femalespecific OSA. For example, It contains features to ensure that females are protected against clusters of events occurring during REM sleep. In addition, when it identifies flow limitation, it responds quickly but gently to make sure patients’ lungs are getting all the oxygen they need.
Why it matters:
More than half of former CPAP female users say they quit therapy partly because it made breathing uncomfortable or otherwise disturbed their sleep. The “for Her” contains new features which are designed to keep the average CPAP pressure lower and make pressure changes more gentle, and therefore more comfortable. In addition, women take longer to fall asleep then men, so they may be disturbed by the CPAP pressure increasing before they need it. The “for Her” features AutoRamp™, which automatically detects sleep at the beginning of the night and starts increasing the pressure after sleep is detected. By delivering effective therapy at lower pressures, this “for Her” mode treats femalespecific characteristics of sleep apnea while maximizing comfort, helping patients embrace treatment faster.
How to get it:
Ask your doctor or home medical equipment (HME) provider if the AirSense 10 AutoSet for Her is the best machine for you? More Information:
CPAP causes Dry mouth?
If you’ve ever felt dry mouth when you take your CPAP mask off in the morning, you’re not alone. Roughly 40% of patients on CPAP therapy experience dry mouth which can cause various side effects such as headaches, dizziness, bad breath, coughing and difficulty talking or eating.
Below are the three main causes of dry mouth:
Dry mouth cause #1: Medications
Before you blame your CPAP mask for your dry mouth, it’s important to rule out other culprits. The Mayo Clinic lists six potential non-CPAP causes that you should discuss with your doctor first:
- Oral medications that list dry mouth Aging
- Cancer drugs
- Nerve damage
- Tobacco use
- Other health conditions
Dry mouth cause #2: Non-heated air
If you and your doctor determine that your CPAP machine’s air is likely causing your dry mouth, you may benefit from added moisture through a heated humidifier and/or heated tubing These devices feed moisture into the air you breathe through your CPAP machine to prevent dryness. The heat level can be easily adjusted to provide more or less moisture – too much could create condensation in your air tube, a condition called “rainout” or “washout.”
Dry mouth cause #3: Mask leak
Whether or not your CPAP machine has humidification, severe mask leak can also cause dry mouth – as well as reduce the effectiveness of your sleep apnea treatment. Mask leak is a leading reason why 45% of former CPAP users quit their therapy. It is common among patients who:
Have an ill-fitting mask. Ask your doctor or mask provider to refit you. Never overtighten a mask just to prevent leak; the resulting pressure could cause discomfort, facial marks and pressure ulcers.
Are on a bilevel machine. Ask your doctor about the benefits of switching to a full face mask that covers the nose and mouth.
Are mouth breathers who are using a nasal or nasal pillows mask. As with bilevel users, ask your doctor about the benefits of switching to a full face mask that covers the nose and mouth.