why light/regular sleep AHI is 6.5, deep sleep AHI 1.1 ??

the same person, the same sleep settings, no medication difference, no alchol, all the same

but light sleep or regular sleep AHI is around 6 , but when I stayed up almost 20 hours so I slept very deeply, my AHI for my surprise came as 1.1

is there a reason for that? I thought the opposite would happen, when we are in deep sleep this is when we have more apnea !!

williamco wrote:... is there a reason for that? I thought the opposite would happen, when we are in deep sleep this is when we have more apnea !!

Normally yes. But there are some of us (join the crowd) who have more apnea events during N1 and N2 (Non-REM Stage 1 and Stage 2) sleep than during N3 and REM sleep. Normally during REM sleep the body switches off our interface to our muscles. This normally makes sleep apnea worse then. But from what I've read today in a small number of individuals the increased "physical" activity seems to improve their apnea events during N3 and REM sleep.

Though it is unlikely that either of us have CCHS (Ondine's Curse), I suspect a similar mechanism is driving the same behavior for a small number of people. If you want to go deep into this, you might want to read:

http://chestjournal.chestpubs.org/conte ... l.pdf+html

In that article it notes:

Unlike OSA, ventilation in CCHS tends to be more stable during REM compared to non-REM sleep,34 presumably due to the presence of additional respiratory stimulation during REM.

The very good news for you is that even an AHI of 6 is considered almost normal.

Of course, thinking about it, you possibly just meant that it felt deeper or less deep. IN that case, then it could be that during what you felt as deeper sleep you in fact hit a lot more REM sleep and/or stayed in REM sleep longer. So, it would only prove that your sleep pattern was very normal. What we feel as deep sleep often does not indicate when and where we hit REM sleep, since we should normally cycle through the various stages of sleep throughout the night.

JohnBFisher wrote: What we feel as deep sleep often does not indicate when and where we hit REM sleep, since we should normally cycle through the various stages of sleep throughout the night.

Not only that, but humans have great difficulty stating how many hours they were asleep or awake the previous night and certainly cannot state accurately what sleep stages they were in.

Reviewing the results of one of my sleep studies, the doctor quizzed me on what hours I was asleep and which ones awake. It became obvious I did not have a good grasp of my "sleep history" when he showed me the EEG results.

The doc said it is common for patients to wrongly estimate the number of hours they slept and the number of hours they were awake.

JohnBFisher wrote:

williamco wrote:... is there a reason for that? I thought the opposite would happen, when we are in deep sleep this is when we have more apnea !!

Normally yes. But there are some of us (join the crowd) who have more apnea events during N1 and N2 (Non-REM Stage 1 and Stage 2) sleep than during N3 and REM sleep. Normally during REM sleep the body switches off our interface to our muscles. This normally makes sleep apnea worse then. But from what I've read today in a small number of individuals the increased "physical" activity seems to improve their apnea events during N3 and REM sleep.

Though it is unlikely that either of us have CCHS (Ondine's Curse), I suspect a similar mechanism is driving the same behavior for a small number of people. If you want to go deep into this, you might want to read:

http://chestjournal.chestpubs.org/conte ... l.pdf+html

Add CSDB/CompSAS as another population presenting their apneas largely in NREM.

John, I caught mention of a brain stem etiology in one of your posts. Wondering if your doctor(s) managed to pin down an etiology yet? Are Chiari Malformation or excessive cerbral spinal fluid (CSF) pressure under consideration?

Guys: what is deep sleep ? is REM considered deep sleep? N3 and N4 are deep sleep?
N1 and N2 are light?
what are the classifications?

where /what sleep stage will the most OSA versus Central apnea fall?

if according to you that we cycle around from stage to stage throughout the night, then sleep stage has no factor in having AHI of 1.1, so still I am asking why when I was tired and slept deeply I had that good numbers?

-SWS wrote:... Add CSDB/CompSAS as another population presenting their apneas largely in NREM. ...

Thanks. I'm coming up to speed as quickly as possible on all of this. So, I'm all ears! In my case there did not appear to be any CompSAS events. Just plain jane central apneas.

-SWS wrote:... John, I caught mention of a brain stem etiology in one of your posts. Wondering if your doctor(s) managed to pin down an etiology yet? Are Chiari Malformation or excessive cerbral spinal fluid (CSF) pressure under consideration?

Many moons ago (over 10 years ago), based on the symptoms, it was classified as Sporadic OPCA. But if you read the literature, it is mostly considered a "holding pattern" until more symptoms emerge.

Unfortunately, about six months ago, more symptoms did emerge. I now struggle with sleep onset central apnea with arousal. Though sleep onset central apneas are fairly common, they are not as frequent and pronounced as what I experience. So, I have a horrible time getting to sleep. And once I fall asleep the central apneas now occur six times as frequently as obstructive apneas. Needless to say, I often feel horrible when I awaken.

I am extremely pleased with my neurologist / sleep specialist. We both felt that the sleep issue was the most urgent issue to address. Normally, I would just manage the symptoms of whatever I have. However, along with the other symptoms, I now struggle with sensory overload. It makes going into busy environments (resturants, church, airports, etc) difficult for me. So, we will aggressively look into this further.

Fortunately, the symptoms at this point do not point to Multiple Systems Atrophy (MSA), toward which some patients with Sporadic OPCA symptoms eventually evolve. There are some similarities, but the central apnea in NREM points away from MSA. I can not completely rule out that as an option since MSA can present in so many very, very strange ways. Plus, it appears I've developed some other classic symptoms, such as swallowing problems.

Thanks for the suggestion of Chiari Malformation or excessive cerbral spinal fluid (CSF) pressure. I had already found the possibilty of Chiari Malformation. I had not run across the excessive CSF pressure. I will do more research into it before my next scheduled appointment with him at the end of February. The good news for both of those is that they offer the chance to improve my situation.

Additionally, we need to explore Obesity Hypoventilation Syndrome (OHS). Though I am not as heavy as most people with OHS, it can not be dismissed. I tend to think it is not OHS since my symptoms worsened as I lost about forty pounds. Due to very poor sleep (and a resulting complete lack of energy), I've regained much of that weight.

Nor can I entirely dismiss diabetic autonomic neuropathy. My blood glucose levels were quite high when diagnosed with type 2 diabetes. However, two things tend to argue against this as the cause. I developed the neurological conditions before I developed type 2 diabetes. And I did have my blood glucose levels and tolerance tested several times during the initial diagnosis of the neurological issues (all normal). Also, my conditions worsened while my blood glucose levels were under good control.

Fortunately, I see this as more of a puzzle than anything else. And I love to solve puzzles. As I tell the customers with whom I work, if it's a new and interesting problem it is good for them, since I am more motivated to solve it.

williamco wrote:... if according to you that we cycle around from stage to stage throughout the night, then sleep stage has no factor in having AHI of 1.1, so still I am asking why when I was tired and slept deeply I had that good numbers? ...

Sorry, I did drag this away from your original question.

I fear it's not as easy as "when I slept deeply". If you just felt that you slept deeply, it's hard to know in which stages of sleep you spent the most time. For an explanation of the stages of sleep, see:

http://www.sleepdisorderchannel.com/stages/index.shtml

Normally, you will cycle through the stages of sleep every 90 to 120 minutes:

The period of non-REM sleep (NREM)is comprised of Stages 1-4 and lasts from 90 to 120 minutes, each stage lasting anywhere from 5 to 15 minutes. Surprisingly, however, Stages 2 and 3 repeat backwards before REM sleep is attained. So, a normal sleep cycle has this pattern: waking, stage 1, 2, 3, 4, 3, 2, REM. Usually, REM sleep occurs 90 minutes after sleep onset.

Stages 1 and 2 of non-REM (NREM) sleep are considered the light stages of sleep. Stages 3 and 4 are considered deep stages of sleep. REM sleep is a special condition that actually mimics being awake. However, in REM sleep you are (obviously) not conscious. Also, your body "disconnects" your ability to move during REM sleep. That "disconnect" process actually tends to increase the number of obstructive apneas, since your muscles are COMPLETELY relaxed.

Without the various leads to measure your brain pattern during when you "slept deeply", I am just guessing. However, I suspect you probably spent more time in NREM sleep when you were very tired than in REM sleep. As a result, you probably had fewer apnea or hypopnea events when you "slept deeply".

Don't you just hate it when someone answers the question with "It depends!"? Unfortunately, it does. But that's my best guess as to why the numbers were better.

Don't you just hate it when someone answers the question with "It depends!"?

Not at all, you answered the question very informatively. I appreciate your answer

I understand that nothing is universal in all patients.
Thanks again

do I understand this correctly: majority have their most apniac attacks in REM, some have their most attacks in N1 + N2
but N3 +N4 are most immune from attacks. ??
does this apply on both types of apnea OSA and central??

williamco wrote:... do I understand this correctly:

majority have their most apniac attacks in REM,
some have their most attacks in N1 + N2
but N3 +N4 are most immune from attacks. ??

does this apply on both types of apnea OSA and central??

Well, it's more like this:

• Most people have more apnea and hypopnea events during REM sleep, due to normal atonia during REM sleep (the "disconnection" of muscles during REM sleep).
• Some people tend to have more apnea and hypopnea events during lighter NREM sleep (Stages 1 and 2), but have little or none during deeper NREM stages (Stages 3 and 4) as well as REM sleep.
• Some people tend to only have apnea and hypopnea events during NREM sleep (all stages), but have none during REM sleep.

The normal atonia during REM sleep is the cause of the increased apnea and hypopnea events. This is very normal. It is also one reason I think an APAP unit makes more sense than a CPAP unit.

A very small number of people experience apnea and hypopnea events during NREM sleep, but almost none during REM sleep. In general, this indicates a decreased control of normal respiratory mechanisms. This can be caused by physical issues such as heart failure, extreme obesity, and problems with the mechanisms to regulate the blood chemistry (which triggers breathing). It can also be due to a neurological issue. Rarely, brain stem problems interfere with regulation of breathing.

But let me be very, very clear. It appears to be rare that someone has increased problems with apnea (obstructive or central) outside of REM sleep. That is why I feel fairly confident when you felt that you slept more deeply and had fewer events, you probably spent less time in REM sleep. Fewer events would tend to indicate less time in REM sleep. It is just a logic puzzle:

• Almost everyone has more events during REM sleep.
• Without indication you might be an exception, the above rule should apply to this case.
• You had fewer events when you "slept deeply".
• You had more events when you "slept lightly/normally".
• Therefore you spent less time in REM sleep when you "slept deeply" compared to "slept lightly/normally".