I don't quite know what to make of this. I guess it's evidence that the ME/SEID patients identified in this study may have any of the whole range of sleep disorders alongside, or as part of their ME - so it looks like there is not a particular type of sleep disorder specific to ME. This bit seems interesting. And, not surprisingly, the prognosis when using sleep treatments is not as good as for otherwise healthy people. I don't think we can conclude too much from this - it's a very small study as far as the ME group is concerned as only 39 patients fulfilled the ME/SEID criteria (21% of 187 patients). And there may be a selection pressure - maybe pwme are less likely than others to get access to sleep centre testing.
From the abstract: How accurate was the SEID diagnosis? I haven't chased behind the paywall but that statement does not fill me with confidence.
I do think it is not uncommon for GPs to mistake orthostatic intolerance for daytime hypersomnia, particularly when patients describe having to frequently lie down and close their eyes during the daytime.
Article on the above: How much does idiopathic hypersomnia overlap with ME/CFS full article here: http://www.emoryhealthsciblog.com/h...c-hypersomnia-overlap-with-me-cfs/#more-15001
Full text here https://sci-hub.hk/https://doi.org/10.1111/jsr.12689 I was skeptical about this claim and suspected that they had used a flawed definition of PEM. I therefore looked at the methodology. Here is what I found: They retrospectively attempted to determine whether patients met IOM criteria or not. Here is how they determined whether a patient had PEM: I have taken the FSS myself and don't remember any question being about PEM. So I looked it up (https://www.sralab.org/sites/default/files/2017-06/sleep-Fatigue-Severity-Scale.pdf) and item 2 is "Exercise brings on my fatigue" which is not inconsistent with PEM but far too vague and likely to generate a large amount of false positives. This is a sign that we need better tools for researchers and doctors wishing to determine whether patients have PEM or not.
I have recently been discussing the issue with operationalization of PEM in studies, and the need for biomarkers. Asking questions is fine for clinical purposes, but not fine for research purposes. We don't just need ME biomarkers, we need PEM biomarkers, even if they are not diagnostic of ME. Confusing exercise intolerance with PEM is a big issue.
Here's the opening paragraph of the PEM section in the IOM report https://www.nap.edu/read/19012/chapter/6#78 The authors don't seem to have read this part, as it clearly says that "PEM is more than fatigue following a stressor".