Is the NIH/CDC going to use the right PEM definition for all their future research? Do patients need to act? Deadline 31 Jan

chrisb said:
Even the word "exertion" troubles me.

We seem to have "activity", "exertion" and "over-exertion" being used interchangeably.

The word "exertion" may suggest merely activity or exercise, but would generally imply some level of activity above a normal base rate. The problem with PEM is often that one may not feel any exertion. One is merely active, and even then only active at a fairly low level. "Exertion" may only be recognised after the event.

I would say (to myself) "exert yourself" only if I thought I was not trying hard enough. It is not necessary to have that feeling to experience PEM.
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Hmmm? I always just took "exertion" to mean anything beyond me laying down, being still, being quiet doing absolutely nothing whatsoever.
 
QUOTE="Octogenarian, post: 32191, member: 559"]To me, that is the most profound statement in the entire discussion. I believe that most people look upon malaise as a psychiatric symptom. I've never understood why people who have exertion-induced (not exercise-induced) muscle weakness and exertion-induced general loss of function refer to it as malaise.[/QUOTE] Strange. I've never heard of malaise being used to mean a "psychiatric symptom". The definition clearly states it to mean physical symptoms felt in the body (ex: such as the physical symptoms one experiences when they first begin to come down with influenza).
 
Andy said:
For those with HR monitors, do you, like me, notice an increase in resting HR during PEM? IF so, should this not be included in the definition?
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I don't wear an HR monitor (but did during my sports), but I know my resting HR. And it seems my HR is a bit higher if I did too much (although I don't have PEM symptoms (yet)).
 
Andy said:
2. For those with HR monitors, do you, like me, notice an increase in resting HR during PEM? IF so, should this not be included in the definition?
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Interesting idea. From my limited experience of using HR monitoring, my resting HR also increases during times of stress or increased mental or physical activity, even without PEM being triggered, in other words while staying just inside my energy envelope. I've yet to collect enough data to know whether this is a signal that I'm going to crash, and what happens during PEM.

I think it could only be included as a sign of PEM if it were verified by research - and if it were not a sign of so many other things like stress, increased activity and infection in healthy people. Is there any research on this?
 
Trish said:
I think it could only be included as a sign of PEM if it were verified by research - and if it were not a sign of so many other things like stress, increased activity and infection in healthy people. Is there any research on this?
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I totally agree that we should have all things verified by research, but so much of this thread is talking about self-reported symptoms, so why not this?
 
Andy said:
I totally agree that we should have all things verified by research, but so much of this thread is talking about self-reported symptoms, so why not this?
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As long as it's not used restrictively in diagnosing PEM - for all we know some people's HR rate doesn't go up. But then the chances are nobody experiences all recognized symptoms anyway.I

Also I would not want people to feel obliged to buy HR monitors to test unless they were planning on and could afford to get one anyway. Some folk are really desperately short of cash.
 
Andy said:
I totally agree that we should have all things verified by research, but so much of this thread is talking about self-reported symptoms, so why not this?
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There is a difference in medicine between symptoms, such as headache, pain, fatigue which are things patients report, and signs, which are things that can be measured or seen by someone else, like temperature, heart rate, skin rashes etc.

Symptoms, by definition, can only be recorded as subjective reports by the patient, so are hard to describe and quantify. Therefore using symptoms as defining features of PEM is subject to problems of subjectivity and terminology. Signs, on the other hand can be objectively recorded.

We definitely would be greatly helped if there were verified signs of PEM, and HR may turn out to be a useful one. But because it is a sign that can be objectively measured, I think we can only claim it as a sign of PEM if there is research to back it up.

For example, do the patients undergoing the 2 day CPET test or other tests that deliberately trigger PEM also show measured increase in resting HR, and does it distinguish PEM from other causes of elevated heart rate in those patients such as stress or activity within the energy envelope. And is it different to what happens to non ME people after 2 day CPET, especially those with other fatiguing conditions that don't have PEM?

Or I could be talking rubbish...
 
Trish said:
For example, do the patients undergoing the 2 day CPET test or other tests that deliberately trigger PEM also show measured increase in resting HR, and does it distinguish PEM from other causes of elevated heart rate in those patients such as stress or activity within the energy envelope.
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Bolding mine. I recently discovered that when I am not taking enough thyroxin my HR actually goes very low. So not only could the patient be experiencing something else which raises their HR, they could also be suffering from something else that masks it.
 
I like this description although not sure it helps with the debate:
"
PEM causes intense exhaustion as well as an upswing in other symptoms that last for at least 24 hours after physical exertion. That may not sound so unusual to those unfamiliar with it — after all, we all need time to recover after a tough workout.
When it comes to PEM, though, little about it is normal or familiar to people without ME/CFS.

It's not just about overused muscles or needing a little extra rest.

PEM can range from moderately stronger-than-normal symptoms to completely disabling. In a mild case, the person may have extra fatigue, achiness, and cognitive dysfunction. In a severe case, PEM can bring on intense flu -like symptoms on top of extreme fatigue, pain, and brain fog strong enough that it's hard to even form a sentence or follow the plot of a sitcom.

That's hardly what the rest of us go through after a hike or a trip to the gym. Also abnormal is the amount of exertion it can take to put people in this state.

As with the severity, the exertion needed to trigger PEM theories case-by-case. For some, it might kick in after a little bit of exercise on top of a day's regular activities. For others, is incredible as it may seem, it can just take a trip to the mailbox, a shower, or sitting upright for an hour."

Although what they refer to as 'a severe case' is what I would describe as 'standard' PEM. (Personally I would struggle just to watch the sitcom, never mind follow it).

https://www.verywell.com/what-is-post-exertional-malaise-716023
 
This link goes to the Solve site with a blog based on the above talk.
http://solvecfs.org/deciphering-post-exertional-malaise/

Key points from a quick skim:
Using description of PEM in ICC definition, they looked at various studies of biological changes related to PEM and how well they reflected the severity of the symptoms. Biological things studied have included gene expression, brain structure and function, cognitive performance linked to brain imaging pre and post exercise. Conclusion of the webinar/blog:

My take home messages:

  • Post-exertion malaise affects both the immune system and the brain.
  • No single outcome or biochemical is likely to explain the complexity of PEM
  • Determining physiological systems interaction will be critical towards understanding the mechanisms of PEM and perhaps how ME/CFS symptoms are maintained and/or exacerbated
  • There is still a large gap in our knowledge of what PEM is in terms of time course, variability, severity and primary symptoms.
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Trish said:
For example, do the patients undergoing the 2 day CPET test or other tests that deliberately trigger PEM also show measured increase in resting HR, and does it distinguish PEM from other causes of elevated heart rate in those patients such as stress or activity within the energy envelope. And is it different to what happens to non ME people after 2 day CPET, especially those with other fatiguing conditions that don't have PEM?
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The elevated HR post exercise is not substantial enough to discriminate between patients and the various other groups you mentioned.

A meta analysis of the various HR findings is likely to be published this year...
 
Leonard Jason said:
I very much appreciate all the thought given to trying to describe PEM, ... I generally do not post my thoughts on these sites, but thought this time, it might be useful to do so.
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@Leonard Jason Thanks again to you and Madison Sunnquist for taking the trouble to read so many comments and for responding. It seems to me you made two central points:

(a) Even though patients said the questions don’t reflect their experiences of PEM, you still found a very high rate of PEM (95%) with your questions. A slightly-revised version using a new question that more closely matched the experiences described here, “worsening of symptoms after mild activity”, generated very similar results. The implication seems to be that even though the DSQ looks different it’s measuring the same thing.

(b) In regard to pacing, you have considered prefacing the question with “if you were to engage in activity“. But, as above, almost all patients reported PEM in any case, which would suggest that there is no need for change. You think this is because patients would be unable to maintain pacing to a meaningful extent over the six-month timeframe covered by the questions.

My comments:

I agree with @Sasha’s general points. In addition:

1. Regardless of your findings of a high rate of PEM, do you have any thoughts on why so many patients don’t recognise the DSQ description but do recognise that from the Institute of Medicine?

2. As far as pacing goes, you are assuming that even patients who pace experience post-exertional malaise at least half of the time. That seems like a significant assumption and it would be interesting to know if there’s any evidence that throws any light on this.

3. I am struck by the extremely high rate of post-exertional malaise reported in your overall sample of over 95 percent. Your large 2017 study including MS patients had 268 mecfs patients (a quarter of your total sample across studies) using an online methodology where the diagnosis was not confirmed by clinical assessment. At least some of these reported having the more general Fukuda diagnosis. I would have expected a substantially lower rate of post-exertional malaise for such a sample.

This made me wonder how we can be certain that responses to DSQ are capturing the same phenomenon reported by patients as post-exertional malaise. Is there a “gold standard”? Could each patient's PEM status be compared between the DSQ result and that from an experienced clinician and from patient self-assessment? I realise that this is a generic problem for all such self-report scales.
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Consulting patients about the NIH/CDC proposals with a survey
It strikes me that it would be extremely helpful to know if the concerns expressed on this thread, about how post-exertional malaise is measured, are indeed shared by patients more widely. For that reason, with a couple of other people, I’m planning to run a survey very soon that will ask patients if either or both of the Institute of Medicine and DSQ PEM descriptions broadly match their own post-exertional malaise. We plan to feed the results into the NIH/CDC subgroup consultation, and we’ll also publish them online.

Thank you
While I am very keen to see a PEM description that patients can look at and say “yes, that’s it”, I want to stress I have a huge amount of respect for you and your work.

You were one of the first to recognise the central importance of case definitions in research probably the only researcher (with your team) to formally study the problem and to develop tools for case definition. Researchers and patients owe you a great debt of gratitude for this. Your take-down of the Empiric criteria is one of the best critiques I’ve ever read. I also believe that your prospective university-based study of mononucleosis will prove to be a game-changer in the field. Thank you.
 
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Simon M said:
It strikes me that it would be extremely helpful to know if the concerns expressed on this thread, about how post-exertional malaise is measured, are indeed shared by patients more widely. For that reason, with a couple of other people, I’m planning to run a survey very soon that will ask patients if either or both of the Institute of Medicine and DSQ PEM descriptions broadly match their own post-exertional malaise.
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I think we really do need a poll at this stage.

Leonard Jason said:
Even though each individual symptom might not reflect the varied presentations of PEM, in our large sample (>1,000 individuals with ME), 95.4% reported PEM (ie, had at least one of the symptoms at a frequency/severity >=2), so it does appear that, overall, we’re capturing most individuals in our samples.
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I'm not sure if this point has been made (brainfog, sorry! Having problems reading now) but my concern here is that just because many PWME report having one of the symptoms you list, it doesn't mean that that symptom is a PEM symptom. It could be measuring some other aspect of ME. Two of your questions ask about fatigue after exertion, for example – perhaps that is simply measuring exertion-intolerance.

Simon said:
I want to stress I have a huge amount of respect for you and your work.

You were one of the first to recognise the central importance of case definitions in research probably the only researcher (with your team) to formally study the problem and to develop tools for case definition. Researchers and patients owe you a great debt of gratitude for this. Your take-down of the Empiric criteria is one of the best critiques I’ve ever read. I also believe that your prospective university-based study of mononucleosis will prove to be a game-changer in the field.
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Seconded!
 
Andy said:
2. For those with HR monitors, do you, like me, notice an increase in resting HR during PEM? IF so, should this not be included in the definition?
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I agree that a change in HR is a useful measure for PEM, and perhaps the only objective measure we have right now, so it would be beneficial for it to be included. However, PEM can be accompanied by either an increase or decrease in HR. I think it's important to capture the significance of a drop in HR as well as an increase, as many don't recognise this as a warning sign.
 
Andy said:
2. For those with HR monitors, do you, like me, notice an increase in resting HR during PEM? IF so, should this not be included in the definition?
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Anecdotally- I know several patients whose resting heart rate is so variable at all times but is not significantly worse/increased during PEM than when they are at baseline.
And if someone is on medication that helps control their heart rate, how would increased heart rate as part of a PEM definition, impact the assessment of PEM for them?
 
Simon M said:
Consulting patients about the NIH/CDC proposals with a survey
It strikes me that it would be extremely helpful to know if the concerns expressed on this thread, about how post-exertional malaise is measured, are indeed shared by patients more widely. For that reason, with a couple of other people, I’m planning to run a survey very soon that will ask patients if either or both of the Institute of Medicine and DSQ PEM descriptions broadly match their own post-exertional malaise. We plan to feed the results into the NIH/CDC subgroup consultation, and we’ll also publish them online.
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Thanks Simon. With an eye towards the deadline, are there any plans on how to actually write the document? If multiple people need to cooperate, it can take more time than expected. Maybe it would be a good idea to start on this already, even if just selecting writers?
 
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