PEM discussion thread - post-exertional malaise

[nataliezzz]

@nataliezzz
There’s a lot here I’m not going to comment on, but I’ll try to see if I understand your assertion.

You believe that there might be a factor X, that in combination with factor Y, causes PEM, and e.g. in combination with Z, causes OI? (X, Y, and Z might be multiple factors.) And X + P results in widespread pain, and so on.

And you call factor X: ME/CFS?

To me, that’s just wrong, because you’re redefining the concept of ME/CFS. But it might be a language thing where what you actually mean isn’t the diagnosis/concept of ME/CFS, but rather the currently unknown mechanism(s) that manifests as the cluster of symptoms we call ME/CFS?

But that still wouldn’t be right because ME/CFS requires PEM, so the mechanism(s) behind ME/CFS must include Y.

PEM is a unique symptom because it is not a symptom of (many) other disorders, but that does not mean that in people for whom all of these symptoms tend to cluster in varying combinations (fatigue, unrefreshing/disturbed sleep, body pain, brain fog, IBS, sensory sensitivities, etc. and yes, PEM) that presence/absence of PEM specifically makes it a different disorder (in my opinion). For example, a quick Google search indicated there's a study that found 47% of a sample of GWI patients endorsed PEM. Let's just presume this is a good study for the moment (I haven't looked into it); I don't think 47% of GWI patients having PEM mean that 47% of GWI patients have a separate/additional underlying disorder (ME/CFS) in addition to whatever is causing their GWI while those w/ just fatigue/pain/cognitive dysfunction/disturbed sleep/etc. w/ no PEM only have GWI.

That's my personal opinion (that I am trying to convince others of the validity of).

PS, I think we might be in the wrong thread again. I don’t know where to put this, because it isn’t really about PEM per se. And the concept of ME/CFS thread is about a specific paper.

I have no idea, either. Sorry.

 

[Trish]

I can't keep up with all these posts. I just want to make one point. Natalie, you keep referring to PEM as a symptom. I think that's wrong. I think it's an episodic phenomenon of a change in the severity and sometimes number of symptoms.

 

[Utsikt]

PEM is a unique symptom because it is not a symptom of (many) other disorders, but that does not mean that in people for whom all of these symptoms tend to cluster in varying combinations (fatigue, unrefreshing/disturbed sleep, body pain, brain fog, IBS, sensory sensitivities, etc. and yes, PEM) that presence/absence of PEM specifically makes it a different disorder (in my opinion).

Why is that your opinion? We need an explanation of the underlying logic here, on a meta level. Does my explanation in the previous post make sense? Is it a correct representation of your opinion?

For example, a quick Google search indicated there's a study that found 47% of a sample of GWI patients endorsed PEM. Let's just presume this is a good study for the moment (I haven't looked into it); I don't think 47% of GWI patients having PEM mean that 47% of GWI patients have a separate/additional underlying disorder (ME/CFS) in addition to whatever is causing their GWI while those w/ just fatigue/pain/cognitive dysfunction/disturbed sleep/etc. w/ no PEM only have GWI.

Can you share the paper? We might already have a thread on it, or one could be made

That's my personal opinion (that I am trying to convince others of the validity of).

Others might need to see the underlying logic in order to assess the validity of the opinion.

 

[Alinda]

Natalies idea, assuming I am understanding it correctly, does make sense to me. A disease can have very different presentations, and I think it could very well be possible that a certain group of some unexplained disorder or symptom that doesn't currently fall under the criteria of what we consider me/cfs, could have the same underlying cause. Once we have a diagnostic marker, we might consider a big portion of people with disorders like IBS to actually have whatever we call "me/cfs" at that point.

 

[nataliezzz]

I can't keep up with all these posts. I just want to make one point. Natalie, you keep referring to PEM as a symptom. I think that's wrong. I think it's an episodic phenomenon of a change in the severity and sometimes number of symptoms.

That's definitely an interesting way to look at it. As discussed above though, some people do seem to experience PEM without having other symptoms at baseline (e.g. the person whose ME/CFS starts with just PEM after they work out hard at the gym, but without ongoing chronic fatigue/malaise at baseline), so it can't always be described as a change in the severity of symptoms (sometimes it's just new symptoms).

 

[Alinda]

That's definitely an interesting way to look at it. As discussed above though, some people do seem to experience PEM without having other symptoms at baseline (e.g. the person whose ME/CFS starts with just PEM after they work out hard at the gym, but without ongoing chronic fatigue/malaise at baseline), so it can't always be described as a change in the severity of symptoms (sometimes it's just new symptoms).

I dont think saying that not having symptoms at baseline means they do not have me/cfs. I would just call the me/cfs, even if it may be (very) mild. It's just nearly impossible to make a diagnosis in those cases, as the majority wouldn't even go to a doctor for such things and just think they struggle with sports, or not even realize it is triggered by exercise and think they have a bad immune system and getting the flu all the time.

 

[nataliezzz]

Why is that your opinion? We need an explanation of the underlying logic here, on a meta level. Does my explanation in the previous post make sense? Is it a correct representation of your opinion?

Your explanation honestly lost me a little, I'm not gonna lie lol (so I can't say whether it's a correct representation of my opinion). But thank you for laying it out in that level of detail; I may try to come back to it.

Can you share the paper? We might already have a thread on it, or one could be made

This study I glanced at refers to another study that supposedly found "Despite observing that Gulf War Veterans (GWV) with GWI who endorse PEM (~47%) have poorer health-related functioning and cardiopulmonary responses to exercise, we also showed that PEM is not uniformly present for all GWV with GWI at 24 hours post-exercise."

I haven't actually looked at either study in any depth (pretty tired right now).

 

[oldtimer]

That's definitely an interesting way to look at it. As discussed above though, some people do seem to experience PEM without having other symptoms at baseline (e.g. the person whose ME/CFS starts with just PEM after they work out hard at the gym, but without ongoing chronic fatigue/malaise at baseline), so it can't always be described as a change in the severity of symptoms (sometimes it's just new symptoms).

I'm struggling to follow things as always but, if the definition of PEM is a worsening of symptoms after physical or mental activity, wouldn't there need to be discernible symptoms to start with in order to tell if they had become worse?
I have assumed that apparently well people who become fatigued after a hard workout are showing a normal reaction that goes away after a good sleep. It can take a triathlete up to ten days to recover.

 

[nataliezzz]

I'm struggling to follow things as always but, if the definition of PEM is a worsening of symptoms after physical or mental activity, wouldn't there need to be discernible symptoms to start with in order to tell if they had become worse?
I have assumed that apparently well people who become fatigued after a hard workout are showing a normal reaction that goes away after a good sleep. It can take a triathlete up to ten days to recover.

That may be the definition (worsening of symptoms), but like I said it appears that some people (likely in very mild/early stages of the illness) experience PEM with no apparent baseline fatigue/other symptoms. It's not like a normal reaction to a hard workout because it has typical features of PEM (e.g. delayed onset, flu-like symptoms, etc.) The personal example of mine was when I was a kid, if I would play really hard all day I would get a fever/exhaustion the next day (my mom called it my "overtired disease" lol). But I didn't have any baseline chronic fatigue (that I was aware of - I was also a young kid though so if I had some mild level of fatigue I may not have been aware of it due to no clear baseline).

"Worsening of baseline" rather than "worsening of symptoms" for PEM could work though.

 

[Utsikt]

so it can't always be described as a change in the severity of symptoms (sometimes it's just new symptoms).

That’s why «and sometimes new symptoms» was included at the end.

I haven't actually looked at either study in any depth (pretty tired right now).

Okay, then I think that’s where we should start. Make threads for them if you can’t find them here already with the search function. I think I shared a guide in the other thread

 

[Hoopoe]

If I started from a well rested state, I can do intense exercise for a short amount of time, without triggering PEM. I can also do other activities without significant problems. In fact that these activities are so unproblematic and rewarding is a problem, because it makes me want to do more. Doing more then leads to PEM. My PEM appears to result from the cumulative effect of activies and rest in the preceding days. Activity here means anything which involves more work than resting, even listening to music, reading or being around other people. Thinking of it as metabolic activity may be close to the truth.

Different parts of the body seem to be able to have their own PEM tresholds and generate somewhat different PEM profiles if stressed excessively.

Maybe PEM is how the body reacts when it cannot tolerate more than a certain amount of metabolic activity within a certain timeframe.

I now have better aerobic fitness and strength than some other healthy people, but have less endurance and begin feeling unwell after too much activity, and get PEM from too much cumulative activity. The main difference between me and a normal person appears to be that they can keep going for much longer and with no significant impairment. At least in my case, it is possible to improve fitness with the right approach, but this has little effect on disability. If someone can't be active for half a day on most days of the week then they can't earn enough money to sustain themselves, and won't fit into many existing systems built for normal people.

 

[poetinsf]

So "ME/CFS" (whatever that is) appears to be able to present as "just fatigue" at least in its prodromal stages in some individuals (I don't buy into the notion that every time a new symptom is added it reflects a different underlying disorder).

PEM could be a spectrum pathology just as ME/CFS is a spectrum disease. My PEM, for example, seems to get shallower and shorter as I continue to recover. At some point, it may become undistinguishable with normal post-exercise fatigue. I could consider what I have now an age-related fatigue if it weren't for some fatigues that is still disproportional to the exertion.

That said, I don't have too much problem drawing the line between PEM and no PEM, because you need to draw the line somewhere. Otherwise, we could end up including idiopathic fatigue or age-related fatigue in ME/CFS as well. Idiopathic fatigue could well turn out to be a mild form of ME/CFS, but we don't know that yet. And including them in ME/CFS without knowing could well muddle ME/CFS research (and perception). Only precaution would be that idiopathic fatigue progressing to ME/CFS is a possibility, so they may need to be careful.