PEM discussion thread - post-exertional malaise

[Utsikt]

Yes and no. It partly depends what form it takes, and what individuals mean by "PEM".

The thing is that you say that it’s always delayed. Someone else will say that it can be instant. And another person will say that it can be accumulated. All based on their personal experiences and beliefs about how their body works.

And because nobody can say that the others are wrong - and because we have no way of actually checking because we don’t know what PEM actually is (in terms of what goes on inside the body) - I don’t see a way around including all three as options.

And we can probably say that patients ‘often report’ that PEM has a delayed onset because that seems to be very common based on the few studies that have tried to look at patient reports.

 

[PrairieLights]

The thing is that you say that it’s always delayed. Someone else will say that it can be instant. And another person will say that it can be accumulated. All based on their personal experiences and beliefs about how their body works.

And because nobody can say that the others are wrong - and because we have no way of actually checking because we don’t know what PEM actually is (in terms of what goes on inside the body) - I don’t see a way around including all three as options.

And we can probably say that patients ‘often report’ that PEM has a delayed onset because that seems to be very common based on the few studies that have tried to look at patient reports.

I get all the types.

 

[Kitty]

The thing is that you say that it’s always delayed. Someone else will say that it can be instant. And another person will say that it can be accumulated. All based on their personal experiences and beliefs about how their body works.

Yes, that's what I mean. We need to know if we're all talking about the same thing, and if not, what the differences are.

It can be accumulated for me too, for what it's worth. It appears to be a single thing that's tipped me over because the symptoms start a day or two after that, but it's illogical for something so trivial to tip someone who was then working full time into PEM. It made much more sense that it was really a case of straws and camel's backs.


ETA: Whilst the instant symptoms do often feel nearly as bad as PEM, it couldn't be a more different experience. There's none of the 'flu-like feeling, sore throat, hoarse voice, shivering, runny nose, hot/cold/hot/cold, etc.

 

[forestglip]

Is this maybe part of a good definition:

All people have a baseline activity level. With regular chronic fatigue, if you exceed your baseline, your symptoms would increase, but they only stay at a constant increased level for as long as you are doing a constant higher level of activity. With PEM, if you were to go significantly beyond your baseline day after day at a constant level, your symptoms would continuously increase with no upper limit.

I don't actually know if it's the case that fatigue/other symptoms would no't keep increasing in something like cancer fatigue as well if you continually did more than you were comfortable with. Or that continually increasing symptoms is universal in ME/CFS if you were to keep doing higher activity day after day.

Graphed here to illustrate with fatigue chosen as the symptom to compare, although of course there can be other symptoms:

 

[Kitty]

With PEM, if you were to go significantly beyond your baseline day after day at a constant level, your symptoms would continuously increase with no upper limit.

Not for moderately ill people. I basically did that for 40 years by working, so it must be possible for there to be an upper limit.

I'm very significantly disabled, I strongly suspect I'd be less significantly disabled if I hadn't kept finding eejit ways to stay in work, but even after all that I'm still not severely ill.

Yet.

 

[Utsikt]

Yes, that's what I mean. We need to know if we're all talking about the same thing, and if not, what the differences are.

I don’t think that’s feasible without a biomarker that we have casually linked to the variability in symptoms.

 

[bobbler]

Important point, and it's something the 'fatigue clinics' don't get at all when they tell people to do 'activity planners' - you can't just allocate a certain amount of effort to a particular activity, because it will take more out of you when you've been overstretched in other ways.

Yes this situation really needs some careful thought because it is a major issue

they don’t seem to get the cumulative either

so focus on splitting things but it meaning it takes more energy in total when the issue is fitting in all the tasks you need to get done in the week vs threshold too small is the real issue is just a distraction at best, but adding cognitive load, risk it never gets finished and potentially takes more overall energy across those three bits which doesn’t solve the issue.


I’m glad @JemPD has mentioned the things she has up thread including the important point about cumulative

and the really important bit about laypersons’ ‘delayed’ vs those who have me who are saying theirs isn’t delayed

the issue is that we don’t get the warnings at the time of doing it when we are more mild (when severe we often have such a low threshold we are already ill and it’s tiny things we know we shouldn’t do and hurt to do)

and the rolling PEM but also ‘rolling up cumulative exertion’ I just don’t know if some only note the crash when it gets to the stop you in your tracks stage or there is that ongoing thing too when you don’t get enough rest to fully rest off the last crash before you have to step back into over exerting as daily life and it’s that

as far as clues for research the delayed PEM is really important to get to the bottom of ironing out if those who were immediate it was immediate because some seem to say that delay is a clue as to the mechanism.

it’s also important to note we can’t just do a planner and alls fine as per fatigue clinics assuming it’s boom and bust rather than energy envelope and there being more likely need for radical resting to get something necessary done eg an appointment being understood and useful (as well as them pulling their finger out in getting adjustments understood as needed ) instead of their fiction if we split out washing up and alternated talking to the kids with doing a physical chore that would fix the weeks cumulation.

plus they no longer understand the term cognitive as they should it seems and have been taught to think it means mental health aka emotion and stress - which is them being wrong and inaccurate but fits what they’d rather deliver vs understanding remembering to go back downstairs to complete the other half of x task might mean more cognitive load than just doing it in one go.

it’s great some people can avoid PEM . I certainly think we should have a world that gives us a fighting chance via fair adjustments that would be little skin off others nose to offer. And shouldn’t be inflicted on us and when we say we can’t do x because it will mean x for 6weeks tgat disability be understood (just because it happens after the issue with PEM I’m being disappeared is partly about people arguing with the word ‘can’t’ )

I think we need to be careful with wirding that infers WE are responsible for our PEM. And moral stuff about those who have to live a dangerous thing of PEM recover PEM recover because medical appointments and showers and must do tasks are all unavoidable all cause PEM and I just radical rest to complete the next then suffer and so on. That isn’t MY management- I’m being tenacious whilst being undermined by lack of support and understanding - and we need to make sure that tone from others that they are happy to take ‘that the lesson is for ourselves and our behaviour’ starts getting squashed firmly.

 

[bobbler]

The thing is that you say that it’s always delayed. Someone else will say that it can be instant. And another person will say that it can be accumulated. All based on their personal experiences and beliefs about how their body works.

And because nobody can say that the others are wrong - and because we have no way of actually checking because we don’t know what PEM actually is (in terms of what goes on inside the body) - I don’t see a way around including all three as options.

And we can probably say that patients ‘often report’ that PEM has a delayed onset because that seems to be very common based on the few studies that have tried to look at patient reports.

How many though have ever definitely had instant PEM?

I get fariguability ie tired during a task

I think we need to be very sure I’m afraid before we say it isn’t delayed because I haven’t met anyone who it is instant fir

I’m not doubting those who say it is but if it is 1 in 1000 then I don’t think we should infer it’s just ‘often’ or ‘might’ be delayed when that’s the distinctive norm

. I’m fine to say there might be the odd person who gets it non-delayed but it isn’t 15-30% even and saying often delayed sounds like not delayed is the norm ?

As it is the patterns in me that are distinctive I think we need to be careful not to disappear them

it’s vital to get PEM right also because it IS the disability and just because it’s once we’ve gone home people say ‘you can do x’ when is it ok to say that when the hidden result is a week of being ill unable to move

if we lose these distinctive ways of talking about it we end up with generic descriptions like fatigue which haven’t helped anyone I don’t think and miss the point

 

[AliceLily]

In the end I think the main thing is to include everyone who gets disproportionate worsening after activity at a level they easily coped with before they were ill, and that worsening isn't just the aching and tiredness that healthy people get after exercise, it's feeling much more ill and having to stop for hours or longer.

I very much agree with this. I was working in my early ME, getting symptoms, feeling ill, something very wrong. I tried to carry on and 6 years later collapsed bedridden with very severe ME. It was the most terrible spiral I wouldn't wish on anyone.

 

[Kitty]

I don’t think that’s feasible without a biomarker that we have casually linked to the variability in symptoms.

All I mean is descriptions, like the ones I've given to separate what I call PEM and what I call rapid fatiguability. (The latter are the symptoms I get immediately, though "rapid fatiguability" is far too simplistic a description for them. I just don't know what other word to use, since what I call PEM is a totally different beast.)

We can surely get some useful separation between the different phenomena that occur in ME/CFS without requiring biomedical tests. It's been part of the process of separating the symptom profiles of other conditions: this kind of rash and this kind of swelling can be X, but unless it persists for at least this length of time it's more likely to be Z.

Maybe we could even make up some new words for them for the sake of the discussion, it might take out some of the confusion. The names don't matter, it's those specific patterns that will help us tighten up diagnosis.

 

[Evergreen]

Regarding immediate PEM, I think Stussman et al. 2023 is interesting. That's the substudy of the NIH study that looked at PEM following CPET. Figure 4 of shows a 8/10 pwME's PEM rating rising between -1 and +1 hrs i.e. during the trigger or immediately after it, whereas figure 3 shows only 2 of the controls reporting that. In both of those controls it had come right back down by 4 hours, whereas only 2/10 pwME's PEM rating was back to their baseline level by 72 hours.

https://neurologyopen.bmj.com/content/6/1/e000529#sec-16

 

[Evergreen]

Maybe we could even make up some new words for them for the sake of the discussion, it might take out some of the confusion. The names don't matter, it's those specific patterns that will help us tighten up diagnosis.

The MEA and the International Consensus Primer and buckets of other sources have always talked about "immediate PEM" and "delayed PEM". Are those terms not enough do you think?

 

[Peter T]

A question for those who experience immediate PEM, does your immediate PEM include the features that don’t occur as part of normal fatigue, such as swollen glands, symptoms unrelated to the triggering activity, etc?

Today I went out for lunch with my goddaughter and her family. I drove there myself (30 min each way). This is much more activity than I would normally undertake. When I got back I fell asleep for three hours and at present I feel tired, a little achy including a mild headache, a little bit befuddled but no more than I was before setting of this morning, and have a runny nose (however I have just had tea and a runny nose often follows eating). It would not occur to me to call this PEM.

At present I could just be exhausted from the increased activity, especially if it goes away with further rest and/or sleep.

However if in the morning I still feel like this or worse I would then consider if I am experiencing PEM, particularly if other symptoms emerge or reemerge over night. Does that mean for me some degree of delay is necessary for me to regard something as PEM and I am defining PEM differently to others, or do others go into the weird and wonderful symptom tangents of PEM without delay?

 

[Utsikt]

Regarding immediate PEM, I think Stussman et al. 2023 is interesting. That's the substudy of the NIH study that looked at PEM following CPET. Figure 4 of shows a 8/10 pwME's PEM rating rising between -1 and +1 hrs i.e. during the trigger or immediately after it, whereas figure 3 shows only 2 of the controls reporting that. In both of those controls it had come right back down by 4 hours, whereas only 2/10 pwME's PEM rating was back to their baseline level by 72 hours.

https://neurologyopen.bmj.com/content/6/1/e000529#sec-16

Figure 2
Post-exertional malaise scaling example based on a qualitative interview. CPET, cardiopulmonary exercise test.

Figure 3
Overlay of post-exertional malaise, physical fatigue and composite visual analogue scales for healthy volunteers. CPET, cardiopulmonary exercise test; PEM, post-exertional malaise.

Figure 4
Overlay of post-exertional malaise (PEM), physical fatigue and composite visual analogue scales for myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) volunteers. CPET, cardiopulmonary exercise test

Figure 5
Visual analogue scale data for myalgic encephalomyelitis/chronic fatigue syndrome volunteers (n=10). CPET, cardiopulmonary exercise test.

 

[Kitty]

Are those terms not enough do you think?

No, because they don't say anything about what they mean by it.

That's how we end up with lots of people with fatiguing illnesses saying they have PEM. It's in danger of becoming a meaningless term, if we haven't reached that point already.

 

[Utsikt]

It's been part of the process of separating the symptom profiles of other conditions: this kind of rash and this kind of swelling can be X, but unless it persists for at least this length of time it's more likely to be Z.

My pure speculation is that the differences were derived from biomarkers that were correlated with symptoms presentation, and not just based on symptom presentation like we would have to do for PEM.

A question for those who experience immediate PEM, does your immediate PEM include the features that don’t occur as part of normal fatigue, such as swollen glands, symptoms unrelated to the triggering activity, etc?

For me instant was like delayed PEM. I get less of it now because I rarely push too far beyond my boundaries. Although instant light-versions of PEM are common for me, it’s just a toned down version of delayed PEM.

 

[Kitty]

However if in the morning I still feel like this or worse I would then consider if I am experiencing PEM, particularly if other symptoms emerge or reemerge over night. Does that mean for me some degree of delay is necessary for me to regard something as PEM

I wonder if, like me, you're describing it as it was years ago. It used to be defined by a delay in onset, but clearly it isn't restricted to that now.

The trouble is that the syndrome that is ME/CFS does not, of course, require a delay for symptoms. Some of them, like OI, can come on within seconds. But we need to be clear whether we're talking about one element of ME/CFS—the delayed often 'flu-like reaction that you and I call PEM—or some aspects of ME/CFS, like the symptoms that can come on very quickly.

They're all ME/CFS, but they're not all the same aspects of it. To diagnose people accurately we need proper descriptions of all of them.

 

[Peter T]

I wonder if, like me, you're describing it as it was years ago. It used to be defined by a delay in onset, but clearly it isn't restricted to that now.

The trouble is that the syndrome that is ME/CFS does not, of course, require a delay for symptoms. Some of them, like OI, can come on within seconds. But we need to be clear whether we're talking about one element of ME/CFS—the delayed often 'flu-like reaction that you and I call PEM—or some aspects of ME/CFS, like the symptoms that can come on very quickly.

They're all ME/CFS, but they're not all the same aspects of it. To diagnose people accurately we need proper descriptions of all of them.

I assume something like OI or light sensitivity is there all the time, only you have to be upright or in bright light to experience its effects which are cumulative, increasing the longer you are upright or in bright light, though obviously it/they vary with current ME levels and or PEM, whereas I see PEM as a distinct state that has to be triggered in some way.

With OI or light sensitivity its impacts start to abate immediately once you lie down or avoid the light source, unless of course you trigger PEM.

For me though you can learn the PEM warning signs you can only really recognise it conclusively once it is triggered and you have observed the features that distinguish it from normal tiredness or exhaustion. Once triggered PEM has a course of its own which it must follow regardless of how much you rest. Rest is necessary for PEM to abate, but it may not be sufficient.

 

[Kitty]

My pure speculation is that the differences were derived from biomarkers that were correlated with symptoms presentation, and not just based on symptom presentation like we would have to do for PEM.

No, some of the descriptions predated biomarkers by centuries. Some by millennia.

You don't need a biomarker to diagnose most illnesses reasonably accurately, and as we haven't got one anyway we're going to have to do it the old-school way. Careful observation, careful language.

 

[Peter T]

Careful observation, careful language.

I second that.