REM only mild apnea

I am looking for feedback what it means to have REM only apnea and share any relevant info that you are aware of this type of condition - mainly the use of positional devices. Below is summary of analysis and recommendation of my Jan '22 PSG. I have a follow up with my neurologist in a week and would like to be prepared to ask some questions

Respiratory Analysis:
Apnea/hypopnea Index (AHI)*: 2.3
NREM AHI: 0.6
REM AHI: 9.6
Mean Sleep % SpO2 (throughout study): 92.0%
Min % SpO2: 84.0%
% Sleep Time with SpO2 ≤ 88%: 0.4%
Total Rera 44
* Above AHI could also be referred to as RDI. (An RDI would in addition
include RERAs that were not scored on this study.)

Number of Events: (NREM / REM)
Respiratory events (#): 3 / 10
Obstructive apneas: 0 / 0
Mixed apneas: 0 / 0
Central apneas: 0 / 1
Hypopneas: 3 / 9
Snoring:
Cheyne-Stokes Breathing:

Position Analysis:
Prone
TST by position (NREM / REM): 0.0 min / 0.0 min
AHI by position (NREM / REM): 0.0 / 0.0

Supine
TST by position (NREM / REM): 160.0 min / 5.0 min
AHI by position (NREM / REM): 0.0 / 48.0

Left
TST by position (NREM / REM): 123.0 min / 57.5 min
AHI by position (NREM / REM): 1.5 / 6.3

Right
TST by position (NREM / REM): 0.0 min / 0.0 min
AHI by position (NREM / REM): 0.0 / 0.0

Recommendations: There was no significant apnea overall but during REM sleep mild obstructive sleep apnea developed. With mild OSA, sleeping in the lateral recumbent position using the aid of positional devices can resolve mild sleep disordered breathing. If daytime sleepiness is persistent, continuous positive airway pressure (CPAP) can be used. Goal body mass index is 22-23kg/m2. Dental appliances such as mandibular advancement devices can be helpful in mild apnea. Caution if driving when excessive daytime sleepiness is present.

P.S: I was diagnosed with severe OSA - AHI 35 back in 2017 and used CPAP religiously since. I underwent a new sleep study last month since I persistently complained to my earlier neurologist and primary physician that my issue (light headedness, dizziness, tiredness etc... these symptoms used to occur in bouts of 2-5 days at a time. Sometimes the intervals between these episodes span weeks) needs revisit as I felt CPAP hasn't had much impact. I was told, there could be secondary issue and I went to few other specialists (allergy, endo, ent, gastro etc..) and gave up after an year as none of them could point to anything specific. For the record, my AHI when using CPAP has always been <2 from day 1 and all through the years and my 2017 diagnosis was based on sleep analysis from a home kit provided by neurologist. I finally decided to get a second view of my sleep condition late '21. The current sleep study from Jan '22 is with another neurologist and was a proper overnight PSG. I went in with as assumption of split-sleep study but I wasn't woken up middle of the night by the technician because my AHI did not meet the threshold for monitoring the second half of the night with CPAP. (Alas .. what I have done to myself past 4 years is what went through my head after waking up from the PSG). I have stopped using CPAP after the current sleep study and it's been 30+ days and no new issues i.e. same feel as before.

I am adding this additional background as it is important for me to understand and move beyond the sleep apnea as a contributor (or not even if partial) to my underlying issue. Thank you for feedback in advance!!

35 AHI to 2.3 AHI seems fishy.

Did the lab tell you to stop the CPAP usage for at least for a week prior to the Jan '22 testing? There is a washout period needed for accurate testing for CPAP users.

Multiple papers suggest a "carryover effect". A speculation is that tissues heal from respiratory vibration damage when supported by CPAP pressure.

https://pubmed.ncbi.nlm.nih.gov/25487311/

https://www.cpaptalk.com/viewtopic.php? ... t#p1406566

No, I wasn't told to stop CPAP prior to the sleep study. Thanks for mentioning the washout effect - I'll make to sure to ask during my next follow up and also weigh it against my experiences - past and current.