POLL: physical vs cognitive PEM - same or different?

Full poll question:
Please compare your typical PEM from physical overexertion with your typical PEM from cognitive overexertion. Consider the typical range of symptoms you get in each case, plus their timing and severity. Do you feel both types of PEM are fundamentally the same process or do they feel fundamentally different? Please use the comments to explain further.

------------------------​

There are several polls on aspects of PEM already but no in-depth direct comparison between physical and cognitive, hence this new poll and thread. Plus most of the polls are members-only but I thought having a public discussion might increase general awareness of PEM from non-physical activities, especially if there happen to be some non-member researchers taking a sneaky look at the forum (you're welcome to join ).

This poll is intended to spark focused discussion about the similarities and differences between PEM following physical vs PEM following cognitive exertion.

I know there may be other things leading to PEM like social exertion, sensory overload and orthostatic effort, and that many activities involve several different types of exertion. But trying to include every permutation was getting too complicated and anyway, for the purpose of analysing possible differences I think it's best to concentrate on examples that are as close as possible to purely physical and purely cognitive activities. Fewer confounding factors.

Clarification on poll option 3:
Some people report they get the same set of symptoms in both types of PEM but that the timing is very different, e.g. PEM always hits immediately after cognitive exertion but after physical exertion it typically hits after a delay. So that would be one example for choosing option 3. Another example would be if half your symptoms occur with both types of PEM but you get an additional set of symptoms with physical PEM only.

Clarification on 'fundamentally the same' or 'fundamentally different':
Say you get brain fog with both types of PEM but it's a little worse with PEM after cognitive exertion. That would still be classed as fundamentally the same. But if you get massive brain fog after cognitive exertion and minor brain fog plus a pounding headache after physical exertion, that would be fundamentally different. So we're looking for the big picture patterns, not for minor detail.

All a bit shades of grey, I know. But the poll is just meant to get the thinking going. The resulting discussion will be the really interesting bit. Or that's what I'm hoping anyway.

 

I'm not convinced I can recognise PEM from cognitive activity. I might have to read several descriptions to know whether or not I get it, and whether or not it's different to PEM from physical activity.

My response to too much concentration is usually after reading, and consists of a tight headache and my eyes flatly refusing to go on focusing. When reading something challenging or unfamiliar, this usually happens after less than 10 minutes.

I don't know whether it results in PEM, though. It's possible I can't do the activity for long enough to trigger it.

 

As @Ravn says many activities will involve different types if exertion.

Cognitive activity -
If I were in the same state PEM will occur much sooner & the deterioration is more rapid with cognitive exertion. I may still have a collection of general physical PEM symptoms that constitute "malaise" the overwhelming one will be an inability to think straight. I will lose maths and communication skills, forget how to operate the kettle and so on.

Physical activity -
PEM from a primarily physical activity will trigger the general group of symptoms that are hard to separate out and identify individually and altogether leave me feeling awful. It can happen immediately if I am attempting a task beyond my current limits, or it can take up to 3 days for noticeable PEM. The delay has changed with both time and illness severity.

Cognitive function will be significantly impaired but to a lesser degree. However, with physical PEM the muscles that were primarily used to carry out the activity will be very painful & much weaker. Unlike when healthy, gentle movement of the painful muscles does not alleviate the pain and stiffness, it make it worse.

Delay in appearance of PEM -
Sometimes when people (not necessarily pwME) feel ill, it is their own immune system fighting the illness that triggers mist of the noticeable symptoms. I wonder with PEM if the symptoms we experience are just a part of what us actually happening. Is it possible to be in PEM but not yet have noticeable symptoms, or the symptoms to have disappeared before the body has fully recovered?

For years I tried to manage my ME by being as active as I could without triggering PEM & avoiding more aerobic activity. So yoga, Pilates, gentle walking. I wonder if I was managing it too close to my PEM threshold, assuming that the threshold is where noticeable symptoms start, and that might have caused increased severity.

 

To me, most aspects are fundamentally the same, but a few may differ. I ticked option 3.

 

I have never experienced delayed cognitive PEM unless it was combined with physical PEM. I recover from cognitive PEM within an hour if I rest, wear ear plugs in a dark room. The physical PEM is delayed by approx 12-16 hours and takes a minimum of 3 days to recover.

I feel nausea/unwell with both though.

 

To add . . . cognitive PEM does affect my gait and at times cause sore/tired calf muscles if I really overdo.

 

I only get PEM from physical exertion. I didn't realize that some of you get PEM from cognitive exertion also.

 

If physical or mental function set up cognitive payback, that would explain why I can't really work out what my answers should be. I really don't know. And don't tell me I should keep a diary – that takes up too much energy, and I don't want to waste mine!

To be honest, I either feel generally yuk or generally tolerable.

 

How do you feel when you're lying down reading with your head propped up a little?

 

i answered 3 . i always get a sore throat even when the activity is just reading threads this is usually the first sign that i have passed my limits i also tend to walk into doorframes when in pem spatial awareness must take up more energy than anyone would think .

 

That's really interesting, and has perhaps convinced me a little more that I don't get it. Those two symptoms are the most reliable indicators that I've overdone things, but I've never had them after working on a computer – not even after spending many hours redrafting and reorganising someone else's funding application, which can be hard work cognitively when you're unfamiliar with the project.

 

I didn't answer the poll because it's just too hard for me to disentangle all the different types of exertion.

I think I'd have to purposely structure my activities to avoid different types of exertion for a while and then carefully record what happened. It's too hard to try to do that type of experiment.

I know I could not trust my memory. Back in the early years of my illness, when I took my husband with me to a lot more doctor appointments, I once told the doctor that I had not had a migraine in several weeks. My husband looked at me and said, "But you just had one on Tuesday!"

I honestly did not remember. I was not trying to be a "model patient" or anything like that. It just had completely slipped my mind.

Anyway, it's an interesting question!

 

I think that must be the case. The physiological changes underlying PEM must surely start during exertion, there can't a be a switch that suddenly flips all by itself 24 hours later or whatever your personal delay is for PEM symptoms to appear. So in that inbetween period we technically have a PEM process going on but it's asymptomatic or presymptomatic or subclinical or whatever you want to call it.

What I'm not sure about is whether it's possible to have such a mild case of "asymptomatic PEM" that you never realise you had it, provided you rested enough after the initial exertion.

What I am sure about is that when I do a second activity during that symptom-free inbetween period, the whole PEM episode will be worse and last longer than if I had started resting straight after the first exertion.

Please, nobody experiment or overexert in any way just to answer the question! Going by memory is a bit tricky, I agree, but I find once I decide to pay more attention to a certain phenomenon I remember future occurrences much better (and despite my best efforts at avoiding them there will be future occurrences of PEM I'm afraid). Of course I then forget other stuff instead, there's only so much room in my brain.

 

The phrase “dangerously okay” applies to this time.

 

The replies to this thread have certainly been more interesting than what is typically written about PEM... Thanks to @Ravn and the others who have replied.

 

Yes. The thing is that pathophysiology of PEM is there from day one of developing ME, even if you don't experience it until 11 years into the illness like I did. ME is PEM.