Central Sleep Apnea and Neuroplasticity

There is a condition known as emergent central sleep apnea that affects about 10% of those undergoing new treatment for apnea with a CPAP. In about 75% of these cases the CSA goes away or is reduced to acceptable levels in about 2 months. In the other 25% it remains a problem. These numbers vary depending on the study, but these ones are in the ball park. So perhaps in 75% of the cases the brain does retrain itself to control breathing better as is suggested in your article. Here is a link to one of the articles on the subject.

Emergent central sleep apnea during CPAP therapy-clinical implications

I was one of the ones in the 25% where emergent CSA did not reduce after 2 months. However after 9 months now, things are starting to get better. Yes, it could be the brain being retrained finally, but I think it is more due to a change on my part to a fixed pressure CPAP mode for machine setup. I think my machine was chasing hypopnea events with more pressure, and the higher pressure was causing central apnea events. The problem with the machine is that it cannot tell the difference between a hypopnea event that is obstructive in nature or central in nature. If it chases central hypopnea with more pressure it just makes things worse. At least that is my theory, and the results I am getting seem to verify it. I was running pressures as high as 15 cm in auto mode, but now I am using a fixed pressure of 11 cm and getting much better results.

Hope that helps some. If you can post more detail on your issues I could give you my thoughts. I find SleepyHead to be invaluable in figuring out what is really going on.

Some comments on your situation:

• The normal progression of CPAP treatment when CSA becomes a problem is to move from an APAP machine to a BiPAP, and if that fails to an ASV. I recall that there are studies which have shown that the move from APAP to BiPAP in about 60% of the cases caused CSA to get worse, not better. I think the treatment path is largely driven by insurance company rules. Start with the cheapest machine and move up when they fail.

• Your ST machine is kind of crude ASV where it is trying to help you breathe and has a backup trigger when your are not making a good effort to breathe. The ASV takes that one step further and locks on to your actual breathing rate and assists you breath by breath to keep breathing. Making the ST type work can involve a lot of trial and error to get the settings right.

• I think there can be an opportunity that slips through the cracks in treating CSA, and it is the most basic -- fixed pressure CPAP but at a low pressure. Some people can be very sensitive to pressure and a CPAP using too much pressure can cause more problems than it solves. That is the direction I have gone with some success. I use a low (relative to where I was in Auto mode) fixed pressure with no EPR, so IPAP=EPAP. It seems to be working. My biggest contribution to AHI now seems to be hypopnea events, which I suspect are central in nature.

• Have you used SleepyHead to examine your flow date in close up detail? A lot can be learned by examining the flow, mask pressure, and minute ventilation relative to when events are occurring. You can also see if Cheyne Stokes respiration or periodic breathing are a problem.

• Could there be any medications which could be contributing to the issue? I have convinced my doctor to cut my dose of a beta blocker for blood pressure in half. These drugs tend to slow the heart rate and I suspect potentially contribute to CSA as a result of lower blood circulation rate.

Based on your numbers I think the SD card has not been in the machine or was not working except for the last night. Certain summary data is kept in the machine memory and you appear to have that for some time. That would include the CPAP Usage numbers, and the Therapy Efficacy numbers. Your AHI for Jan 7 was a bit high, but your averages for longer periods look good, providing they are valid. I think there may be a bit of a setup issue in SleeyHead as it is not showing all categories of Apnea events like Clear Airway events. Your Obstructive + Hypopnea events do not add up to the reported AHI number, so something is amiss.

Your Leak Statistics and Pressure Statistics look to be one night only - Jan 7. This makes me think the SD card was missing or bad. There is no real way to recover that, unless you had good data in SleepyHead before you had SD card issues? If you did have good data before let me know and there may be a way...

Your one night leak data was not all that bad. I have seen much worse. The Daily Detail page would show much more. Mouth leaks tend to be isolated with flat tops somewhere above 25 l/min.

If you can post the daily detail page it would be much more helpful in determining how you are doing. If you want to exclude personal details one way is to go into SleepyHead and use File, Edit Profile, and page through the screens using the Next button, and delete those personal details. You cannot change your User Name once you have set up that Profile. The only way is to create a new Profile with a less descriptive first name or nickname. You can probably do that without losing much data. What you have is on your card, so when you create a new profile it will be transferred from your card into the new profile.

If you are using Windows 10, another option is to use the included Snipping Tool. I find it very handy to capture sections of a screenshot (to exclude personal details for example).

It looks like you now have good data in SleepyHead from Jan 7 on. From what I can see it appears to be only reporting unclassified and hypopnea events. Your AHI is not all that bad. Total time apnea seems on the higher side, but better recently. From the statistics page it looks like the machine is running pretty much at maximum 20 IPAP and 14 EPAP. There is not a lot one can tell from the statistics page beyond that. Similar with the Overview page. To tell more you would need to post your Daily Detail page. Bonjour may be able to help you better than I can with your BiLevel machine. It should be capable of going up to 25 cm of pressure, so the machine is not the limit. Your current setting of max IPAP of 20 is the limit. That said I noticed you reported you were suffering from Aerophagia, and that is often related to pressure. Perhaps once you get used to the pressure, an increase in pressure may be in order.