5-HTP : Modes of Action?

I've previously conducted two experiments with 5-HTP: 

5-HTP and its effect on my AHI and sleep in general (link)

5-HTP and its effect on my snoring profile (link) 

Both gave encouraging results. In fact they were so encouraging and surprising that I really would like to know more about how it has the effect that it does, and would it work for other people?

My studies are so small (as I am only experimenting on myself) and the potential for a pharmaceutical solution to Sleep Apnoea and Snoring so attractive that I would love to see further research and a larger trial for 5-HTP as it poses so many questions:

• Does it work for anyone other than me?
• Is it only effective for Mild Obstructive Sleep Apnoea?
• How dose-dependent are the effects? Does too high a dose limit the effectiveness (as with Melatonin)?
• Does the positive effect fade with long-term use?
• Are there any negative effects?
• Are the co-factors that I've been taking with this brand of 5-HTP (label from manufacturer's website here) partly responsible for the effect?

Although I can't find the results of any direct studies looking at AHI or snoring, there is a fair amount of medical literature relating to Serotonin (which 5-HTP is an immediate precursor to, that is 5-HTP is metabolised into Serotonin by the body).

From the existing literature I've tried to piece together possible mechanisms for the effects that I've observed.

THE EFFECTS OF SEROTONIN ANTAGONISTS IN AN ANIMAL MODEL OF SLEEP-DISORDERED BREATHING

By blocking serotonin activity in a breed of dog prone to obstructive apnea, it was possible to induce snoring whilst they were awake along with a collapse of the upper airway, which was reversed when serotonin activity was allowed to return.

Veasey SC, Panckeri KA, Hoffman EA, Pack AI, Hendricks JC
http://ukpmc.ac.uk/abstract/MED/8564132

"Veasey et al" blocked the action of serotonin (5-HT) in Bulldogs while they were awake (using agents known as 5-HT Antagonists). Daytime snoring was observed. Furthermore using live CT scanning a collapse of the upper airway was observed. These effects were reversed when the action of serotonin was unblocked.

This gives a clear indication that serotonin is essential for maintaining the muscle tone of the upper airway.

So, why does this tone drop off during sleep? During sleep (and especially during REM sleep) muscle tone is reduced. In REM sleep we undergo muscle atonia (deactivation of most muscles - this is also the cause of sleep paralysis). It is also shown that Serotonin activity is at its lowest during REM sleep. So a greatly reduced level of serotonin activity leads to a greatly reduced level of muscle activity during REM sleep.

It doesn't seem that simply activating certain Serotonin receptors can undo this muscle atonia. This is a bit of a leap on my part, but it seems that 5-HTP excites all types of serotonin receptors rather than just a few that are excited by various other pharmaceutical methods. Maybe this is because that by allowing the body to convert the extra 5-HTP to serotonin you are allowing natural metabolism of 5-HTP to 5-HT rather than just a localised or specific 5-HT receptor activity.

There are papers that support the fact that 5-HTP has an effect where 5-HT has none (albeit in motor function).

5-HT PRECURSOR LOADING, BUT NOT 5-HT RECEPTOR AGONISTS, INCREASES MOTOR FUNCTION AFTER SPINAL CORD CONTUSION IN ADULT RATS

Y. Hayashi, S. Jacob-Vadakot, E.A. Dugan, S. McBride, R. Olexa, K. Simansky, M. Murray, &  J.S. Shumsky

Exp Neurol Jan 2010

We conclude that selective 5-HT or 5-HT receptor activation was not effective in improving 2C1A hindlimb function after incomplete lesions. In contrast, the 5-HT precursor 5-hydroxytryptophan (L-5-HTP), which activates all classes of 5-HT receptors, increased both %WS and hindlimb activity

http://ukpmc.ac.uk/abstract/MED/19840787

In the following paper by Ling, Bach & Mitchell it is shown that 5-HTP has the ability to reveal and activate a latent pathway in the spinal cord in hemisected rats (similating an incomplete spinal injury).

SEROTONIN REVEALS INEFFECTIVE SPINAL PATHWAYS TO CONTRALATERAL PHRENIC MOTONEURONS IN SPINALLY HEMISECTED RAT 

Liming Ling, Karen B. Bach, Gordon S. Mitchell

Exp Brain (June 1994)

These results indicate that serotonin converts ineffective crossed phrenic pathways in the spinal cord to effective pathways. It remains to be determined whether serotonin is both necessary and sufficient in this modulatory process, or if it is a nonspecific result of increased phrenic motoneuron excitability.

http://ukpmc.ac.uk/abstract/MED/7843300

5-HYDROXYTRYPTOPHAN-INDUCED RESPIRATORY RECOVERY AFTER CERVICAL SPINAL CORD HEMISECTION IN RATS

Shi-Yi Zhou & Harry G. Goshgarian

J. Applied Physiol (June 2000)

Because experiments were conducted on animals subjected to C2 spinal cord hemisection, the recovery was most likely mediated by the activation of a latent respiratory pathway spared by the spinal cord injury. The results suggest that serotonin is an important neuromodulator in the unmasking of the latent respiratory pathway after spinal cord injury. 

http://ukpmc.ac.uk/abstract/MED/11007592

So we have two potential mechanisms by which 5-HTP could work: 

1. By loading with 5-HTP it allows the body to metabolise it to 5-HT activating all classes of 5-HT receptors thereby reducing the effects of muscle atonia in REM without completely inhibiting REM atonia.
2. By possibly activating a dormant pathway in the spine to the phrenic nerve (increasing breathing effort). 

As we've seen by my sleep-study results, my sleep apnoea is obstructive in nature, so it is unlikely that increasing breathing effort would reduce my AHI as I still make breathing movements but they are rendered ineffective by the obstruction in my upper airway.

If 5-HTP does work in these two ways then it's possible that 5-HTP may have a positive effect on both Obstructive and Central sleep apnoea as item 1 above relates to OSA while item 2 relates to some forms of CSA. 

Sleep Apnoea: A Family Thing?

Readers of this blog will know that both myself and my son have Obstructive Sleep Apnoea (OSA). My son was diagnosed first which encouraged me to look at my own sleep.

Before realising that I had OSA we'd just assumed that my son's OSA was related to his paralysis, but knowing that one of the risk factors for OSA is having a family member who has it, I imagine that he could well have had OSA anyway and that his paralysis is something that exacerbates it.

I wondered if either of my parents also had sleep apnoea, so I asked them if they'd mind having a simple sleep study in their respective homes in which I'd monitor pulse rate and oxygen saturations (SPO2) along with nasal airflow and the Zeo headband in order to get an idea of their sleep staging. 

Relevant histories:

My dad has long complained that he sleeps poorly with frequent awakenings. His wife confirms that he snores loudly regardless of sleeping position. So there is a fair chance that he has Obstructive Sleep Apnoea. Many years ago it was suggested by a doctor that he had narcolepsy without cataplexy (based on symptoms alone, no diagnostic studies were performed) and no more was said about it. He keeps irregular sleeping times and can often wake at 2am and remain awake until morning.

My mum keeps a fairly regular sleep schedule but complains of feeling tired in the mornings. She also describes a feeling of her "throat closing off" as she tries to sleep which repeatedly wakes her. She prefers to sleep prone. She also has high blood pressure which is controlled through medication. Her blood pressure is highest in the mornings. I wondered if these were signs of Obstructive Sleep Apnoea too.

The Results:

I looked at their AHI, and the breakdown of Apnoeas and Hypopneas. Although oxygen saturations alone aren't the "be all and end all" of sleep apnoea, (It's possible to have disrupted sleep and still have respectable saturations), I've included the graphs here for comparison.

To give an idea of what they should look like, here is a recent graph of my son's SPO2 whilst using his BiPAP. His AHI was 0.3:

For more details of his treatment see the "Non Invasive Ventilation" blog post.

My dad had an AHI of 35 (Severe). His oxygen saturations (SPO2) are shown below (they did drop to 53% at times, but I've left the lower scale of the graph at 70% to give a simple comparison between us, but it's clear to see where they dropped below 70%). Some nights that we recorded he had a lower AHI of around 25, so he would be placed in the "Moderate to Severe" category.

 

My mum had an AHI of 10 (Mild). Her oxygen saturations are shown below. My mum sleeps prone, so I suspect her supine AHI would be higher but the simple monitor that I used didn't measure body position (SPO2, Pleth, Pulse, Airflow only) so I am unable to see if she deviated from a prone position in the night).

My untreated SPO2 (Supine AHI of 15) (Mild to Moderate):

My son's untreated SPO2 (typical Supine AHI of 40) (Severe):

Ideally I'd like to monitor both my parents using Stowood's Black Shadow sleep monitor, to determine sleeping position (and hence Supine AHI - a measurement that I feel is a more reliable indicator) and an audio recording of any snores that take place.

Where now?

My dad doesn't currently feel the need to treat his condition (maybe because he has slept that badly for so long that it seems normal to him). This is a concern because there are so many other conditions that can arise from untreated sleep apnoea but I respect his right to choose. He is retired and doesn't drive so work and car safety aren't issues.

My mum has considered a range of treatments from side-sleeping to dental appliances but after (repeatedly) hearing how much my son and I like CPAP / BiPAP she decided to opt for a CPAP trial. This will take place shortly. We're both intrigued to see if CPAP will have a positive effect on her morning blood pressure along with improving sleep quality.

Based on the fact that so many of my immediate family have sleep apnoea I think that it would be prudent for my daughter to be tested too.

CPAP - It's well worth taking the time to get it right

Previously I'd used CPAP for a few days to try to get an idea of how my son felt as he started to use it.

Initially I tried it in the hospital where it was prescribed. I used it whilst awake using a variety of masks and pressures to see what high pressures felt like and to see how it responded to me exhaling, holding my breath, trying to talk and opening my mouth etc. Then I used it for a few nights. I wanted to know what problems he could encounter because he isn't able to move to correct them for himself, so I thought that if I were familiar with some of the problems it'd at the very least give me a frame of reference for when he told me what issues he was having.

For practical reasons I purchased an additional CPAP (technically an APAP machine - Auto CPAP). I chose the Resmed S9 Autoset, which to its credit doesn't look like a piece of medical kit; it looks more like a modern bedside clock radio. Yes, the pressures should be set by a professional and you need a prescription to buy one but it looks like a piece of consumer electronics, which is a great thing because it doesn't make your bedroom look like a High Dependency Unit.

Resmed also make coloured "skins" for the device which would be helpful when trying to introduce it to children as part of their therapy.

The S9 has a coloured display screen which allows the user to adjust the comfort settings and climate control and to allow them to see an instant indication of whether the mask is fitted properly along with a morning readout of your AHI (Apnoea Hypopnea Index).

The S9 records overnight summary data and detailed data to an SD card, which via the ResScan software allows you to see the following data: 

• Respiratory Events via flags on the timeline (Central Apnoeas, Obstructive Apnoeas and Hypopneas)
• Pressures chosen by the machine at any given time
• An indication of snoring level
• Flow (allowing individual breathing waveforms to be seen)
• Leak
• Flow Limitation (an indicator of the degree of obstruction)
• Compliance data (how long I used it for)

An example of the data from one of the nights that my son used it is shown below.

All of this is very useful to have access to because it lets you see a record of the choices that the machine makes which helped me to trust that the machine wasn't going to deliver a high pressure unless there was a good reason to. This is all recorded automatically while you sleep at home (or in the sleep lab). Compared to a one-night study in a sleep lab (especially a split night study) the data may be a more realistic representation of your sleep because you'll be sleeping in a familiar place and adhering to your usual routine.

The output that we collected from the ResScan software was viewed by my son's doctors during his initial trials with CPAP before changing over to Bi Level ventilation (BiPAP / VPAP / BPAP)

I chose Resmed's Swift FX Nasal pillows as they left a lot of my face free, they didn't feel trapping and are easy to remove if I really felt like it in the night.

My son uses them with Bi-Level PAP and prefers them over a wide range of masks that he's experimented with, although he can't move below his shoulders he has learned to remove the Swift FX pillows by a head movement, so he feels comfortable using them as he knows that he can take it off if needed.

The S9 has an "AutoSet" mode where it can alter the delivery pressures as it deems necessary. The machine can be forced to work within a range of pressures. I decided to let the machine have a free reign and didn't force it to choose between limits. 

I managed to keep the CPAP on for most of the night, but I remember waking frequently and moving the tubing and to keep checking the machine because... well to be honest... I was nervous. The machine is very quiet which was another reason to check it every time I stirred in the night in case I'd managed to turn it off in the same way that I snooze the alarm clock. 

Over the few days I was tired because, as I said above, I'd been awake due to my own anxiety and the strangeness of it all, also I managed to get caught up in the tubing one night! The following evening I arrived home from work and dived face down into bed without CPAP. Due to my sleep debt over the previous few nights I experienced sleep paralysis and a lucid dream, so it wasn't all bad.

...and that's where my trial with CPAP ended.

However, recently I've fallen in love with CPAP and in particular Resmed's S9 Autoset (the photo above is my S9 beside my bed), and here's how it happened...

There's a lot to get used to with strange tubes and masks on you and your bed plus a new machine on the bedside table - and that's without getting used to the pressures that the machine delivers... considering this, my experience wasn't really a fair trial for CPAP, especially since it is considered to be the "Gold Standard" in treating obstrucitve sleep apnoea.

In hindsight, I suspect it would have been better to begin by choosing a low pressure and just wearing it to get used to the mask and tubing - almost a dress rehearsal before the therapeutic pressures are used.

My CPAP experience was well over a year ago and before the time that I started this blog and before the time that I realised that I had mild to moderate obstructive sleep apnoea. Now that I have a better understanding of my own sleep and have found various ways to reduce my AHI without CPAP I decided to give it another go and compare the results, after all we now had my son's "old" (barely used) S9 Autoset sitting in a cupboard doing nothing because he actually needed Bi-Level PAP.

This time I paid a lot more attention to my own AHI.

I also decided to eliminate the uncertainty of whether the machine was going to wake me with a high pressure during the night, so I did a gradual titration over several nights using the "Straight CPAP" setting of my son's backup Respironics BiPAP S/T.

I found myself making slow deliberate breaths while I tried to sleep. This wasn't particularly helpful, because (even if you aren't wearing CPAP) when you think about your breathing you find yourself consciously taking over, and to be honest this is something that our bodies do better if we don't let consciousness interfere with it.

However, I found myself calmly waking up every now then wondering why I wasn't breathing and finding that I had to consciously take a breath, I listened to machine respond, then dropped back off to sleep. This happened maybe 5 or 6 times that I remember during the night and wasn't anything like waking with a snort or a choke, in fact it felt quite strange. 

In the mornings I took a look at the data (the BiPAP S/T also records data to an SD Card that is readable via the Respironics Encore Viewer or Encore Pro software. 

I found an explanation for the breathless awakenings...

Whilst the obstructive apnoeas were few and far between, the machine had detected "Central Apnoeas". These are when the airway is open yet no air flows. This can be from a variety of causes, but from my own baseline sleep studies I know that my apnoeas are usually obstructive in nature, so I knew that these new Central Apnoeas were because my chosen pressure was too high.

If breathing is too effective at clearing CO2 from the bloodstream then central apnoeas can occur because during normal breathing the brain sends a signal to breathe when CO2 in the bloodstream reaches a certain trigger level. We then breathe causing gas exchange, (taking oxygen in and exhaling CO2), after which our bodies produce more CO2 which reaches the trigger level and the cycle begins again.

If the CO2 level is too low then the brain doesn't need to clear it, so doesn't send a signal to breathe. Our oxygen levels then drop which wakes us up and allows us to consciously take a breath.

I adjusted the pressure down by 1 cmH2O the following night, but I still wanted more data. Were these really "centrals"? A night wearing the Black Shadow Sleep Monitor whilst on CPAP confirmed that they were.

I switched machines back to the Resmed S9 Autoset because it allows you to see a lot more data as opposed to the trend data given by the Respironics BiPAP S/T. It actually allows you to look at the data at a much higher resolution (you can see every breath taken) so I could then verify any detected apnoeas for myself.

Along with the lower pressure setting, I set the S9's EPR (Expiratory Pressure Relief) to full (3) which drops the pressure down by 3cmH2O (or 1 or 2 cmH2O, depending on your chosen setting) when it detects that you are exhaling. This is very helpful, even for psychological reasons as not only does it help you to exhale, but it provides a form of tactile feedback letting you know that the machine is "listening" to you and not trying to force a gale into your nostrils whether you like it or not.

One interesting thing that the S9's additional data allowed me to see was the moment that I stopped doing those forced breaths I that I mentioned above. This is the moment that I fell asleep. 

I fell asleep fairly quickly, and woke once when I turned onto my side and found that I needed to adjust the nasal-pillows slightly.

The following morning I checked the data and found that the central apnoeas had cleared and my AHI was a very respectable 0.4 which varied over the next few nights but still remained under 1.0.

One night I found that the S9 data showed that I'd been quietly snoring, it was also on this night that my AHI was the highest that I've had so far whilst on CPAP (0.9), although this is still a fantastically low AHI.

So the next night I crept the pressures up by 0.4 cmH2O, only to find that the snoring cleared but some central apnoeas returned, so I dropped the pressures again. It became obvious that finding a pressure that was perfect for every night was going to be a challenge.

Of course I realise that there is going to be some "natural variation" from night to night due to factors such as body position and time spent in each sleep stage but wouldn't it be good to be able to pin down what the other less obvious variables are?

My main factors are related to body position (apnoeas are more likely and frequent when I sleep supine) and REM sleep (when muscle tone is decreased in the airway), but I suspect that other factors during the day play a part.

This is where the S9 Autoset excels: In AutoSet mode it adjusts the pressure it delivers based on your need at the time, so where "Straight CPAP" is limited because it can only give me one pressure throughout the night meaning that 8cmH20 may be too much for me at some parts of the night (causing Central Apnoeas), yet not adequate for other parts of the night) where 10 or 11 cmH2O is more appropriate.

I set my S9 to "Autoset" mode and adjusted the settings so that the machine would work within fairly restrictive limits just to get me comfortable with the idea. In the morning I could see from the ResScan software that the machine had delivered the maximum permitted pressure at some points in the night, so I gradually extended the pressure range over a few nights until the machine didn't reach my ceiling limit and was able to deliver the necessary pressures.

The following graph of the pressure that the S9 delivered over one of the later nights illustrates how my requirement varies through the night. 

On the night above I woke myself up snoring after several hours (just before the red vertical line), so I raised the lower limit and went back to sleep, this is why the graph above shows the delivery of pressure that is lower than permitted minimum pressure at the start of the night.

Had I been prescribed straight CPAP based on the pressures titrated on this night then I would have had to have a constant pressure of between 10 and 11 cmH2O to eliminate all my obstructive apnoeas. However, the chances are that I would have then had more central apnoeas occurring. A compromise pressure of 9 cmH2O would have removed the majority of apnoeas but would have been inadequate when my obstructions were at their most severe. There could also have been central apnoeas occuring at this pressure for some of the night.

The textbook, "Sleep Medicine Pearls" by Richard Berry MD describes this well with a case study of a patient unable to tolerate the high pressures needed to treat his obstructive apnoea. If you have access to the book you can find the details under Patient #43. In fact the whole book is packed with case studies that provide a unique insight into treating sleep issues.

If high pressures can't be tolerated it may be preferable to have a lower than optimal pressure setting just to ensure that some benefit is obtained, although it is likely that these patients would benefit more from Bi-Level PAP which allows a much lower expiratory pressure.

In Autoset mode, the S9 allows low pressures but can deliver the higher pressures when necessary, giving you the flexibility (and comfort) of both in one setting. 

Some good news: my nose isn't as big as I thought...

I found that I woke up several times in the night and had to adjust the nasal pillows but each pack of Swift FX nasal pillows come with three sizes of pillows. I found that when I decreased the size of the nasal pillows to the medium size (although the large were comfortable and the leak minimal) the medium pillows were more comfortable and needed a lot less adjusting when I first put them on and hardly any throughout the night.  

I slept really well and took a look at the display screen on the S9 when I woke.

I was greeted by an AHI of 0.0 and a green smiling face telling me that the nasal pillows were a good fit and weren't excessively leaking.

The ResScan software also confirmed the Zero AHI. 

Now that I use the Autoset mode, my AHI is always under 1.0 regardless of what position I sleep in or even if I've had a glass of wine.

It actually feels good to sleep on my back again, I'd been using the Rematee side-sleeping belt for a while and found that I missed sleeping on my back. With CPAP I didn't ache when I woke up. CPAP was surprisingly unrestrictive and I soon learned a manoeuvre to clutch the hose and move it with me if I wanted to turn in the night.

To be fair I could have just let the S9 go on full unrestricted auto from day one and it would have delivered the same pressures, but from mine and my son's previous experience with Non-invasive Ventilation, a large factor in whether it is successful is down to whether the sleeper (patient) feels comfortable with it, yes the numbers are important (after all that is the whole point of the therapy), but the patient experience is also key as that alone will probably be the biggest factor in whether they are "compliant" with it (ie use it for 4 hours or more a night), after all many PAP machines don't allow the user to see their AHI data so they can only judge based on how it feels.  

Another part of the experience is the mask that is used. There is a wide choice of masks available, and it's important to find one that is right. Also humidification can help people feel more comfortable with PAP therapy, this is something else that should be available to them along with all manner of accesories such as hose holders - really anything that will prevent someone giving up. That said, CPAP therapy isn't right for everyone as my son's situation shows, so good communication with a committed Sleep Consultant is vital in order that the right treatment be offered. 

I think looking into things in this detail was necessary for me, although it was a rather involved way of getting used to CPAP and trusting it, it has been well worth it. I feel a lot more awake in the mornings (generally only sleeping for 7.5 hours now) and my AHI has been consistency the lowest it has been in probably 20 years.

I think the graph below speaks for itself.

CPAP is a clear winner and one that is likely going to be impossible to beat but that's not going to stop me trying out other apnoea remedies to see if they can come close.

CPAP has also made a huge difference to my snoring, the results of which I'll post in a few days. 

For the future: 

• I'd like to see if the pressure requirement decreases if I take a dose of 5-HTP at bedtime.
• Although I don't intend to change my nasal pillows, I would like to see what difference other masks make to the experience.

Useful Links

Michael F. Fitzpatrick, Christi E. D. Alloway, Tracy M. Wakeford, Alistair W. MacLean, Peter W. Munt and Andrew G. Day
Can Patients with Obstructive Sleep Apnea Titrate Their Own Continuous Positive Airway Pressure? 
(full text PDF available to non-subscribers via the link)

Gao W, Jin Y, Wang Y, Sun M, Chen B, Zhou N, Deng Y. 
Is automatic CPAP titration as effective as manual CPAP titration in OSAHS patients? A meta-analysis.

Sleep Onset Apnoeas / "Throat Closing"

One of the search terms that people find this blog with surprised me by how frequently people search for it, there are several variations but these two sum things up well:

• Throat closes as I go to sleep
• Choke as I fall asleep

I hadn't really considered this before but I really should have done because it happens to me, and one of my parents. Normally when I experience those throat-closing moments they are accompanied by the first snore / cluck / snort of the night, a flash of whatever broken dream images were going through my mind and the knowledge that I'll soon be asleep. I guess it's something that a lot of us experience but don't really talk about it because it sounds a little strange.

Polite and usual "sleep chat" is usually along the lines of "Did you sleep well?" and not much deeper than that which is a shame because it's such a fascinating subject that few of us speak about because many (wrongly) consider sleeping to be a waste of 8 hours and some even see it as a weakness ("Sleep is for wimps" etc etc).

I've been using CPAP for a month or so now and have been adjusting my own pressures based on the sleep study data that I record each night. When I reviewed each night's data, one of the things that stood out about breathing as we drop off to sleep was how it changes at sleep onset (the moment that a sleep lab would declare that we are now asleep).

This becomes more pronounced with CPAP (or at least for me as a relative newcomer to using CPAP for myself) because when I first switch the machine on at night I instantly become aware of my breathing and try to control it. Oddly, consciously controlling our breathing is something that we don't do very well and it is best left when our bodies do it for us automatically. Can you imagine the chaos that would result if we had to consciously take every breath or control every heartbeat?

The following is a few minutes of data representing my breathing as I was dropping off to sleep whilst wearing CPAP. It's taken from Resmed's ResScan software (click for a larger version).

The breathing on the left is when I was awake, it is clearly different to the smooth regular breaths on the right side of the graph. Falling asleep is what brought about the change as I "forgot" to consciously breathe and my body took over.

So far so good, but on several nights I noticed that the handover from from awake breathing to asleep breathing wasn't so smooth... 

Notice how there are gaps in my breathing? This is from a night where some apnoeas were still occuring; I remember that as I was falling asleep I experienced at least two of those "throat closing" moments. The apnoea briefly woke me as left me realising that a moment before I was asleep, which also seemed to shift the hypnagogia into my conscious mind and then into my memory because this night was also a night that I remembered a lot of it.

Several different images and phrases came and went as I drifted off to sleep. The Zeo recorded that I briefly entered REM as I fell asleep (possibly causing a loss in muscle tone resulting in apnoeas)...

This is something that I see on many nights when I look at my Zeo data, but in the interest of accuracy, Zeo do point out that if your sleep is generally healthy with 7-9 hours per night and no feelings of tiredness during the day that this brief period of REM could be wake being misinterpreted as REM. It could be that N1 sleep mixed with brief periods of wake (from my respiratory arousals) were interpreted as REM by the Zeo (as wake is so similar to REM). 

The following night my sleep looked very different and I achieved a lot more REM along with no apnoeas or hypopneas recorded at sleep onset, intriguingly the Zeo data doesn't show me passing through REM as I fell asleep. So this could actually be REM, although this could also be because there were no respiratory related arousals during the transition from wake to sleep.

With the Black Shadow Sleep Monitor I've seen that less significant respiratory events are linked with altered REM sleep, in my case a series of hypopneas leading to a Lucid Dream. This raises an interesting issue that may provide some insight into dream formation.

I used to be comfortable with those throat-closures before I knew I had Sleep Apnoea as they had become so familiar to me. I used to use them as a way of knowing that I'd soon be asleep. In a strange way I will be sad if they go because after each "cluck" or snort I'd briefly wake and commit the partial dream or hypnagogic image to memory and would be able to study sleep as I drifted off.

Famously people have used a technique that relies on waking from hypnagogia in order to remember it which involves napping in a chair whilst holding a metal spoon over a metal tray or plate. Once you drop off to sleep you automatically release the spoon, causing a clattering sound which then wakes you allowing you to recall what you saw and heard.

I see my sleep onset apnoeas as such a system, alebit a naturally occuring one. I think that during the times that I want the best of both worlds of having the apnoeas at sleep onset but sleeping safely for the remainder of the night that I will experiment with setting a RAMP on my CPAP which delays the maximum pressure by up to 45 minutes, giving me time to explore the hypnagogic world.

Knowing that I have obstructive sleep apnoea and that the first apnoeas of the night are usually at sleep onset, I would suggest that anyone who experiences these throat-closures at sleep onset should at the very least be aware that they could have Obstructive Sleep Apnoea and look out for other symptoms. The best thing to do it get it checked professionally as it could also be a sign of another condition such as Acid Reflux (GERD) or Laryngospasm.

Mandibular Advancement Devices: #1 Snoremate

If you've never seen one of these devices before, imagine it as a two gumshields stuck together, with the gumshield for the lower teeth fixed so that it forces the wearer to jut their jaw forward. The mandible is the jawbone, hence the term "Mandibular Advancement"

The idea behind this is that forcing the jaw forward creates more room in the airways by shifting muscles and fat forward slightly, reducing the likliehood and severity of airway obstruction.

Mandibular advancement (either by a specially made dental device, or by surgery) is a tried and tested concept of reducing snoring and sleep apnoea, so I'm not really putting that to the test, but rather I'm trying out the off the shelf concept, although my snoring is sleep-apnoea related, so unless the device can remedy the apnoea, I doubt that it will affect my snoring. 

SnoreMate

This is an off-the-shelf (but custom fit) mandibular advancement device (MAD).

The SnoreMate is made from a thermoplastic that you dip in hot water to make it soft, then bite into it to form a custom fit for your teeth. The SnoreMate can be adjusted by re-dipping it in hot water if you feel the need to advance your lower jaw more to increase the effectiveness of the mouthpiece, something that I did after a few nights of using it.

It was easy to mould, and is the most comfortable of the two mouthpieces that I've tried so far (the other device being the SomnoFit) which I found was too bulky to be comfortable for me). I was surprised that on the first night It stayed in place until around 2am, and on subsequent nights (to get used to it before I monitored it) it remained in place until the morning. It was actually quite easy to get used to. In fact it was surprisingly comfortable, so I purchased a second Snoremate and moulded that one slightly further forward rather than risk losing the comfortable positioning of the first one.

However, there are a couple of drawbacks to the mouthpiece, the main one is saliva build-up! I found myself waking at night just to swallow and clear my mouth. The other drawback is that my gums and a couple of teeth ached for a few of hours in the morning.

As far as snoring reduction went, using the method explained in this post, I was very surprised. I imagined that everything I used in addition to the Rematee would either improve on the Rematee's effect or make no change. I think that the graph shows why I was surprised...

The SnoreMate actually made my snoring louder! This would have been very annoying for anyone in the house as I managed to reach 98db (about the volume of a drill drilling!). This is an unacceptable volume when you consider that I was already sleeping on my side and wearing a mandibular advancement device. Although to be fair, it is an anti snoring device, and my snoring is more than snoring, it's related to sleep apnoea.

In the following clip it resembled a moose-call.

However, I had a lower AHI for the three nights (mean 2.05) with one of the nights using Snoremate with the Rematee giving me my lowest ever AHI of 0.77.

If I had to speculate as to why the snoring increased in volume (and sounded slightly different in tone) yet the AHI was lower, I'd have to say that it was probably due to the fact that, by design, it is impossible to breathe through your mouth with the SnoreMate, so the air has a to take a different path through the nasal passages, rather than through the open mouth of the snorer.

Even wilder speculation:  The SnoreMate was probably doing what it was intended to and tightening / stretching the muscles in the airways meaning that they were less prone to relaxing, hence less hypopneas. Again, further speculation, but it is possible that this also caused the snoring to be louder in the same way that in deflating a balloon a screech caused by keeping the neck taut is louder and higher pitched that if you were to let the neck relax causing a quieter lower-tone rapserry sound.

I was so intrigued by this hint that it was working, that I've made an appointment at my dentist to have a professional Mandibular Advancement Device constructed for me and I'm looking forward to being able to compare the results. My hope is that the professional device will allow me to further advance my jaw, keeping my airway muscles even tighter, elimating my apnoeas and maybe my hypopneas (and hopefully snoring too).