Epidemiological and clinical factors associated with post-exertional malaise severity in patients with ME/CFS. Ghali et al. 2020

https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-020-02419-4

 

Smart study by people who seem to understand the nature of the illness.

The enteroviral trigger has been subject of much discussion, especially lately. What it looks like is that enteric origin may be a higher risk factor but is not necessary. It also shows the difficulty, basically the same as with COVID-19, that the infections can only be categorized under Influenza-like, i.e. flu-like, because it's impossible to tell one apart from the other in individual cases based on symptoms alone.

PEM was divided into 4 quartiles and is distributed as such:

Mild: 23 (11.7%)
Moderate: 74 (37.6%)
Severe: 73 (37.1%)
Very severe: 27 (13.7)​

Anyone tried the CDC questionnaire?

This plainly suggests PEM is a much more reliable assessment than fatigue, something obvious but dismissed by our BPS overlords, especially the last part:

Technically incorrect in that it has been known for a long time that youth offers better outcomes for recovery, but somehow the conclusions arising from that fact did not consider the other side of the coin.

This suggests that significant harm will arise out of the current attempts to psychologize IBS, as GI infections present a higher risk of ME. The interaction between invading pathogens and the enteric microbiome may be quite relevant here.

Lots of talks over the years of "leaky gut", perhaps a less formal term for something that needs further research. Circulating bacteria have been found in the blood of ME patients following exertion challenges, this may explain their origin.

Every time I see discussions of GI symptoms in ME I can't help but think of Peter White's outraged reaction at the suggestion that GI symptoms were common in ME, something that in his opinion, as one of the foremost experts on CFS, is simply not true. This was in response to pleas for the 2007 NICE committee to include them. White was wrong. White is always wrong.

No GET. No CBT. They are literally the worst possible advice.

It's refreshing to see research exploring symptoms by people who know their stuff. Hopefully larger studies give us better information and more reliable findings.

 

There were only 11 patients with a gastrointestinal infectious onset, so not sure if this is a robust finding.

The most interesting finding is probably that fatigue scores were similar among the PEM severity groups. That seems to show that these are independent constructs.

 

PEM studies always catch my attention, especially ones that give a very good description of PEM in the introduction like this one does (it also uses an ICC cohort so all patients should by definition experience PEM).We sure need to know much, much more about PEM, how to identify and measure it, and what its relevance and implications really are.

Yet reading through this study the main take-away is that we also need much, much better instruments to study PEM.

1) So they used the "PEM item from the standardized self-reported questionnaire of Center for Disease Control and Prevention Symptom Inventory (CDC SI) [20]." The reference [20] is this paper: https://pophealthmetrics.biomedcentral.com/articles/10.1186/1478-7954-3-8 which discusses the "CDC CFS Symptom Inventory" which mentions "unusual fatigue after exertion" (table 2) amongst a whole raft of other symptoms like sore throat and unrefreshing sleep. It seems to be primarily designed to ascertain whether you have CFS, not whether you have PEM. In fact, there's no actual mention of PEM in this referenced study so I don't understand what the "PEM item" in the present study is supposed to be, the whole questionnaire or just the item "unusual fatigue after exertion"? Looking at the scoring section, the latter - "unusual fatigue after exertion" - appears to be the most likely. If so, I'm sorry but "unusual fatigue after exertion" ain't no measure of PEM, not by itself anyway. Which the authors know very well going by how they describe PEM in the intro - so why use "unusual fatigue after exertion" as a measure of PEM (if I haven't misunderstood something)?

2) They only asked about the last month, and they only asked about frequency and severity of PEM. One month is surely too short a period to assess frequency - or anything much, really - and they completely fail to take into account the impact of pacing on frequency and severity of PEM despite the fact that they discuss patients using pacing to reduce PEM.

3) Importantly they fail to investigate how much/little exertion is needed to set off PEM. Or if there's a link between the level of overexertion and the severity of PEM.

Not sure about this one. How do you decide whether your symptoms are those of an infection or of PEM? Do you simply have an infection or do you first have an infection which then sets off PEM? My personal sense is that infection and PEM are separate phenomena but that having an infection lowers PEM threshold, i.e. it takes less exertion to set off PEM when also having an infection. But it's hard to disentangle given that both infections and PEM present with flu-like malaise.

The second of the two tools proposed by the IOM for PEM assessment is the De Paul symptom questionnaire*. I wonder why they didn't use that? Unlike the CDC SI self-reported questionnaire it was specifically designed for PEM though it still doesn't account for the impact of pacing, nor assesses the amount of exertion that leads to PEM.

*https://www.leonardjason.com/wp-con...st-Exertional-Malaise-Questionnaire-DPEMQ.pdf

And the CDC SI self-reported questionnaire can be downloaded here: https://www.cdc.gov/me-cfs/pdfs/symptom-inventory-questionnaire-508.pdf

Is this something we could do better as a patient group? Many of the patient associations have good descriptive information on PEM but there don't seem to be any better scales than the two above to use in research.

ETA: Fixed plural of phenomenon (= phenomena). I do hope that once we find a cure for ME that the brain fog at least is reversible. I would really like to have my former command of language back!

Moderator note: This post has been copied and the following discussion of PEM has been moved to a new thread:
Defining and Measuring Post-Exertional Malaise - a discussion

 

yes, that's a useful finding.

 

Maybe the lack of correlation between fatigue and PEM is because fatigue questionnaires are useless for measuring absolute fatigue.