Exhaustion in ME/CFS, what is it and what causes it - discussion thread

Is there something different occurring in the muscles of pwME who experience pain/PEM? Does your pain occur on a regular basis and intensify during PEM?

I'm thinking of the study done by Dr. Rob Wurst and the findings of amyloid-containing deposits in skeletal muscles of pwLC that worsen during PEM.

I have never experienced pain. I also don't have pain during delayed PEM and I've had ME/CFS for 33yrs.

 

I think from that detail we are talking about different things here. It's really hard trying isolate things under different terms, but it has flagged to me how the term 'exhaustion' is quite different to 'fatigue'. SO yes I'm talking about exhaustion and then entertaining whether it fit with your suggestion of exhaustion fitting that fatigue model you linked. And how exhaustion leads to those effects/symptoms. Which I don't think is fatigue. But it's such a fuzzy term it has made itself Popper's theorem can't disprove it isn't because it morphs by being ambiguous. I'm happy to look at the paper but I for this reason don't think the terminology fatigue is anything other than unhelpful really for us. It's meaning is in the eye of the beholder.

Which I sort of knew in the way the BPS talked about the term fatigue that it was inaccurate to what we had, and when I discovered there was fatiguability made much more sense (I think they just misinterpreted what people were saying /or perhaps deliberately assumed what people said wasn't what they meant). I never had fatigue in the sense that you see those documents on 'managing fatigue' talk about where trying to chivvy your body along 'improves it'. I had the permanently forcing myself so knew all those tricks to have to perform despite yet it made it worse.

If i'd known about that mis-sell of what they meant by the term 'fatigue' at the time I'd never have used it. It's more ill-fitting than the term 'tired' which at least theoretically has the meaning that it is 'relative' ie 'that person is tired compared to their normal' so someone with severe ME could have had an appointment which tired them. Sad thing with that 'tired' term is how ambiguous it is and how normal people assume that how they feel when they've done something 'normal level of tiring' is what you mean. When they need to think proper emptying and hurting level of things like spending 5 days in transit on economy flights and in airport seats wide-awake with the odd snatch of sleep whilst hauling around heavy luggage. I don't think they would use the term 'fatigue' then either, but 'exhausted'. So I guess they are very different things because you can exhaust your supply of eg hairgel.

It is quite an interesting one to explore - because I think it might help to get to the bottom of explaining the misunderstanding of the condition. THe other usage of the term fatigue is eg in describing soldiers 'showing signs of fatigue' eg in their muscles or in cognitive tests for example with air traffic control to monitor the impact of fatigue on performance. In the sense of athletic training it might be used to describe someone who is back in training after eg a race just a few days before and is in their performance 'showing fatigue' vs 'exhaustion' being the theoretical phenomenon that is supposed to be temporary at the end of a 'leave it all on the track' race or training session.

So I guess fatigue could be described as a 'signal' where exhaustion is 'empty', but it is a very wooly term with a circular definition really (people know it is fatigue in athletes, soldiers, air traffic controllers because their performance level drops and the observer knows what they've done) and can cover something expected and normal. Whether they are describing utterly different things, and bunged together because in some situations you see them in close time sequence. I think it is interesting that other people note that one of the issues for PEM is that certainly when less severe your body lets you do too much/you don't ever know what that threshold moment was for PEM when you were doing it at the time (and it is cumulative), which I guess is what some of the newer apps are trying to work on giving people warning signals for.

What I'm not now 100% convinced of is whether fatigue is just an utter red herring which came about from lazy observation (lump and dump 'they all seem fatigued') where they weren't hearing the specific actual symptoms and timing of those from pwme but instead just thought it was 'fatigue' so only heard it was that. But that term is double-meaninged in itself it seems because fatigued could mean over-limit/needing rest or that laypersons thinking you seem a bit lethargic or sleepy.

And it has been insightful to me because it has made me realise that it absolutely isn't a medical term at all. And just relates to normally 'relating something back to needing to take a break to recover or rejuvenate'. It is indeed 'expected' or seen as something that could be tackled. Exhaustion relates to an 'outcome' and sort of describes a hard threshold/state. That such a state can happen from what others mightn't even see as exertion (again others unbundling that term to note we use it because it feels like an exertion) eg sitting up for long enough can lead to exhaustion is quite a specific term. I'm almost tempted to say I'm reticent to assume there is any fatigue to do with it at all/it's a red herring. I would get fatiguability where it would affect the quality of my speech for example

This is an interesting one for me to return to because I feel like it's sparked a few moments of thought for me, that will take time to try and unbundle and form. There is something about the term 'fatigue' assuming moveable thresholds and 'you can go into something fatigued already' being the purpose of it as a term, where fatiguability saying 'my threshold for x is y' and relating to exhaustion and signs of deterioration of perhaps both performance and health.

It doesn't help that these terms haven't been firmed up into being used in a precise terminology, and then you try and give good faith to any paper using them so are trying to read such terms and find the meaning they intended from them by looking into the methods etc.

On the other point - yes being immobilised is common (but I'd also split that down into very specific different ways too), but the fainting was an example of how it's 'ill' like 'exhausting yourself' when ill. So the concept I'm describing is like when (before ME) I had severe tonsilitis (not like most people had it understanding it as sore throat, but like one of the few who got really nasty tonisilitis) and then tried to have a shower too early and ended up having to give up as I'd gone utterly white and had to completely lie down. Fragile and collapsing. That's what happens, at pushing at the threshold and beyon when you shouldn't.

 

You are making meaningless distinction. Wherever you say 'exhaustion', you can well substitute it with 'fatigue' and nothing changes. Different fatigue/exhaustion could be caused by different things, but both refer to the inability to do what you need/want to do.

- the boxer went through 11 rounds and he was so fatigued/exhausted that he was no longer able to throw a punch
- an MECFS patient was so fatigued/exhausted that she couldn't hold up a phone to her ears
- The fatigue/exhaustion is not relieved by rest or sleep
- The depressed person felt so fatigued/exhausted that he couldn't get out of the bed

I'm guessing that you are trying to make the distinction to explain what's going on under the hood with the concept of "energy", or vice versa. But redefining fatigue/exhaustion when it makes no difference to your argument will only detract. I think it would be more productive if you explain more convincingly how energy can get suddenly drained after 24 hours of doing nothing to cause PEM.

 

Ok well no that’s BS.

you can exhaust your battery or bank account or options

I think you do get that

mot feels like I approach this open mindedly as a question where you decided for some reason there was one pre-set answer.

fatigue being exhaustion doesn’t even make logical sense in language for most sentences and changes the meaning for nearly all others. I’m struggling to think of an example where a switch isn’t changing the nuance to an extent it’s red herring leading things off in a different direction. Tho I’m aware this goes unnoticed because healthy people use these casually without being specific

all your examples just demonstrated that you changed the meaning by the word switch. I think you are just arguing it might not matter to the subject in that one-off situation because they aren’t vulnerable and it’s not medical.

But the thing is if one of those eg the boxer was ill then that change would be so so significant . You’ve just picked contexts where the switch and bait doesn’t cause as much harm. To make it sound ok for the ones where that error does cause harm. So it’s more justifying the inaccuracy than demonstrating they aren’t changing the meaning.

In fact these are probably could ones to use for a course (as per my last para below) with some of mine above to point out to people how specificity matters. If the n combined with the examples where the change (said collapsed or exhausted but ‘heard fatigue’) caused a real problem. It’s interesting because some of the testimonies do at least use the term exhausted in certain examples

happy for you to give me more detail on why you are so fixated on the idea of fatigue being this - it might help make more sense to know where you are coming from

I’m happy to muse on a topic to expand thinking hence you’ll see me trying to think something through to see if there is worthwhile things to be achieved from going through that loop, but not really looking for sophist type argument y stuff/approach here as it adds nothing to knowledge

thanks for bringing this up though because it has really helped make clear where the issue is for BPS and how ‘fatigue’ came from people not understanding words potentially and doesn’t fit and there might be an issue where some people don’t use specific enough meanings of words so they seem to think these are the same.

no wonder it’s been so hard. Maybe in a medical context saying ‘the drip of x has been exhausted’ is understood but then it shows how problematic the brainwashing to switch peoples words is if they are told to hear instead ‘fatigue symptoms that can be pushed through’.

So terminology obviously needs to be flagged as not just an area needing to be worked on but clearly needs both training and oversight as it’s been used as a tool for switch and bait. I believe lots of other bigotries have had to tackle language too in the past so I guess it’s not new at least to an organisation to work on

 

I personally describe fatigue, exhaustion and delayed PEM differently. I use these terms very carefully when I describe this to a medical professional.

 

Yes, losing power in your muscles is not what I would consider 'fatigue'.

 

There certainly is a problem with lack of proper definition for the various forms of fatigue/lassitude/lethargy. There's a lack of quantifiability, so there's no reliable way to distinguish between exhaustion, fatigue, and various other forms of "I'm not feeling up to that task". Some of those words to carry meanings, but they are different meanings to different people. I asked elsewhere whether there was a language that did have clearer definitions for these feelings, but no one said there was. I think that until we develop ways to measure human thoughts and perceptions, we aren't going to have a clear definition of "fatigue".

I wonder whether it might be easier to find a way to talk about those ME symptoms without using those undefined terms.

 

Yes. And I'd add in something like 'exhaustion from fatiguability', which some people don't want to think on to understand is different from 'fatigue' but is very specifically different from that when used as a generic term inferring 'seeming or feeling a bit slow or tired' and we don't know is 'the same' with what is the underlying mechanism as whichever model someone wants to claim is 'all fatigue' but normally focuses on something quite specific (ie their area of interest)

If you know you can't talk for long without getting exhausted and your performance being extremely different that's fatiguability and when you've done that it's 'exhaustion' as a correct term. But describing collapsing (as described not someone rewording it having 'not understood' what was actually said to something that fits better for them) shouldn't be replaced with 'fatigue' as a term which infers someone 'feels tired, but if they do a bit of shushing on the spot or had a strong coffee they could get going'. They are opposite things in that sense.

And just because if you screamed at someone who can't move because of exhaustion and eventually they do move because their body isn't safe under that screaming and they need to get somewhere safe to rest and end up engaging adrenaline somehow to do so isn't 'proof' either.

 

I think this gets back to the whole point of this thread and power output is a critical measure of that. When we think back to our healthy selves, I recall that explosive power of launching myself out of bed or even up a flight of stairs. I've completely lost all that, even to the depths of feeling like I need dredge up the last of my power just to roll over in bed, the power is just not there.

Rather than just the word 'fatigue', I suggest we use should the term 'muscle fatigue' to differentiate from sleep fatigue. Importantly, muscle fatigue is the inability to maintain power output (or exercise intensity), resulting in a decrease in performance. The term 'fatigue' IMO is a consequence of a loss in muscle power (muscle fatigue), and the rate of that loss of muscle power of patients with ME/CFS would be interesting to compare with healthy individuals and other conditions.

There are such tests, such as a dynamometer, which measures grip strength and measure differences in muscle force over time.

We often use the term broken battery to describe ME/CFS. I think its very relevant, particularly for the use in an active toy that demands bursts of power. Power in a battery is measured as a factor of current and voltage. As a battery is becoming exhausted, the voltage drops off and diminishes the power output. If we were to work through all the steps to determine the elements that affect the power output of a muscle, we might find some suspects.

The BIG question first is, is it central fatigue or peripheral fatigue, or both? The recent Wallitt study suggesting 'effort preference' is more akin to central fatigue whereby the thought to action muscle contractions is inhibited. Then, there is peripheral fatigue which is the chain of events from the peripheral nerve to muscle action potential to calcium release to cross bridge tension, which determines the muscle force and power output. My thinking is that it is probably both, but I'm also thinking by far the severest of the muscle fatigue is peripheral fatigue. Defective mitochondria can certainly help to explain the loss of type II fibres and inability to sustain moderate power output, but I've also lost strength, which suggests the glycolytic muscle power is inhibited as well.

So, back to the the thread topic: what is exhaustion and what causes it...by following the physiological steps that produce muscle power, and what might be contributing to the loss of it (other than exercise)?

 

But interestingly even that varies longtitudinally. For example I had gland swellings and sore throats constantly during the first 10 -15 years or so and being undiagnosed at that point assumed I was prone to recurring tonsillitis/throat infection . But as I worsened in function it faded away and definitely since my progression to severe and mature late stage illness it isn't in my symptom set anymore but instead constant POTS and headaches and other things are that we'rent present during my mild and early stage illness. Longitudinal variation is extremely poorly researched and an oft overlooked dimension.

 

However, inability to maintain power output is not necessarily muscle fatigue. There are other possibilities that limit ability. There's a lot of neurological interaction involved in making muscles do what you want.

 

@Jonathan Edwards This is a test I've often suggested, but hadn't heard that any study actually did the test. Do you have a citation for such a study? If there was as study that conclusively proved that ME muscles are not unable to respond properly, it should be linked as a sticky, so members don't waste time and money trying treatments intended to improve muscle function.

 

Chronic Asthenia refers to lack of energy and strength and is a symptom of an underlying acute or chronic condition. Examples of conditions that may cause asthenia include infection, myocardial infarction, cancer, multiple sclerosis, and myasthenia gravis.

Includes CFS.

 

No but I think a study was done by Andrew Lloyd a long time ago, using electrical stimulation. It probably is not definitive but I don't think it should be ignored. Also my understanding is that on day 1 CPET tests ME/CFS patients produce normal output, or at least comparable to sedentary controls.

 

This one?

A. R. LLOYD, S. C. GANDEVIA, J. P. HALES, MUSCLE PERFORMANCE, VOLUNTARY ACTIVATION, TWITCH PROPERTIES AND PERCEIVED EFFORT IN NORMAL SUBJECTS AND PATIENTS WITH THE CHRONIC FATIGUE SYNDROME, Brain, Volume 114A, Issue 1, February 1991, Pages 85–98

https://academic.oup.com/brain/article-abstract/114A/1/85/330956

 

That is likely the one I was thinking of. @Nightsong

 

A paper has been published this week in Nature that calls it Sickness Metabolism. This has further helped my understanding of it and how it can lead to malnutrition. https://www.nature.com/articles/s41423-024-01192-4#Sec2

 

The only time I remember feeling like I had no strength in my muscles were in the very severe years. It's possible that I am not recognizing a subtle lack of strength now because I have had ME so long.

At my very severe ME onset I will never forget not having the strength to chop carrots, or hold a phone to my ear for long. I also didn't have the strength to sit up in a chair for long. I remember the receptionists at my doctors surgery finding it funny how I was restless and unwell in the waiting room. They could have been laughing at something else but they kept looking over at me. My spine and neck felt like jelly.

I had to take all food back to my bed to eat because sitting at a table was too difficult. To this day I still take food back to my bed. I could sit at the table now but the effort of having my arms up higher to eat will add extra exertion to my day and I would rather save that exertion for other things more important that need doing.

With the severer levels of ME there is much more going on. More types of weakness, exhaustions. I even had different types of stomach nausea. From my own experience it felt like the ME was getting so critical that it was putting me at risk from secondary illness and their symptoms.

Here I am now 20 years later and I have nowhere near the symptom load I had back in those years. So anyone who hasn't experienced severe ME I can tell you it is a different world and experience, a place you never want to experience.

 

It's irritating that I have to add to this but just in case the BPS are reading. I am not recovered nor have I made a permanent recovery from severe ME. I am still very disabled and I have to rest afternoons and evenings to keep from deterioration and to hold on to the level I am at now.