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

[Esther12]

Thanks a lot to @Simon M for posting about this - I've left the tab with the thread about this consultation open for weeks now, knowing it's important and that I should go back to it. It's so easy to get caught up in other things.

 

[Sasha]

Thanks a lot to @Simon M for posting about this - I've left the tab with the thread about this consultation open for weeks now, knowing it's important and that I should go back to it. It's so easy to get caught up in other things.

I'm also very grateful to @Simon. This is very important and we need to be on the ball (though I understand why we haven't been so far!).

 

[Graham]

I, too, rarely get PEM, simply because not only do I keep a careful eye on what I do, but so does Kathy. It's very seldom I push myself hard enough to get proper payback. I would find it very hard to describe my PEM symptoms. I'm also intolerant of lactose and of onions, but as I completely avoid them, similarly, I couldn't really describe the consequences in that sort of detail because it has been 15 and 45 years since I avoided them.

The last time PEM happened to me was after screening Unrest in November, and that was mostly pushing myself mentally too much. I can't remember the previous occasion.

In that sense, PEM is a symptom of treating the illness incorrectly, so in what way is it a measure? To me the measure is the inability to risk pushing myself beyond a certain (very low) level because of painful payback, as opposed to the temporary discomfort that happens if you do that when you are healthy. It is the limitations of what you can do to avoid PEM rather than the nature of the PEM.

I never get that burst of energy, that "let's get going" surge that I used to. I am slow right at the beginning.

That's not much help, is it?

 

[Subtropical Island]

All great comments, want a stronger like button.

Clarification on ‘trigger’: yes exertion is by far and away the main trigger. However, sometimes things are made worse by environmental factors rather than outright exertion.
Eg having young rambucious (sp?) children come to stay gave me a small crash despite very careful pacing to well below my normal limited safe zone.
NB I think this is part of why sometimes PwME find crashes come unpredictably. (And why I am only mild/moderate fluctuating: I have control of my environment...usually).

That said, it’s cumulative too. Sometimes I think I got away with it (my PEM is 24hrs almost like clockwork) but then do more and it tips the balance. So that’s a problem with the word trigger. Hmmm

 

[Sasha]

In that sense, PEM is a symptom of treating the illness incorrectly, so in what way is it a measure? [...] That's not much help, is it?

Actually, I think it's a great help because I think it indicates that PEM questions shouldn't ask, 'How often do you get symptom X?' or 'How severely do you get symptom X?'

They need to be more along the lines of, 'Based on your experience, if you pushed yourself too hard physically, which of the following symptoms would you experience?' or something like that, as well as asking about delay (and bearing in mind that the amount of delay or the timing of the PEM peak may vary depending on how hard you push things).

 

[Andy]

All great comments, want a stronger like button.

Clarification on ‘trigger’: yes exertion is by far and away the main trigger. However, sometimes things are made worse by environmental factors rather than outright exertion.
Eg having young rambucious (sp?) children come to stay gave me a small crash despite very careful pacing to well below my normal limited safe zone.
NB I think this is part of why sometimes PwME find crashes come unpredictably. (And why I am only mild/moderate fluctuating: I have control of my environment...usually).

That said, it’s cumulative too. Sometimes I think I got away with it (my PEM is 24hrs almost like clockwork) but then do more and it tips the balance. So that’s a problem with the word trigger. Hmmm

Personally, I think change of usual environment is a very important thing to take into account, whether it be leaving your normal environment or relatively large changes occurring within your normal environment. When I'm at home, the vast amount of time i know what will be happening and when, so I can 'budget' accordingly. Once I leave home, all bets are off, and it's the need for additional processing of variables that drains me. So in your example the rumbustious children added a large additional cognitive load that you weren't used to.

Now how do we easily express that as some kind of question?

 

[Daisybell]

For me, the exhaustion post-exertion is both peripheral -in the muscles used, and central. It’s the central part that is the telling bit I think. So just now, I’ve been overdoing it unavoidably and I feel shattered - in my core/chest. It feels as though it would be dangerous to push through - I don’t recall that when I was well, even after running a half-marathon. Pushing now leads to tachycardia etc..
Is that others’ experience too? Does that somehow differentiate us from others or not?
Malaise doesn’t cover that I don’t think.

 

[Denise]

Actually, I think it's a great help because I think it indicates that PEM questions shouldn't ask, 'How often do you get symptom X?' or 'How severely do you get symptom X?'

They need to be more along the lines of, 'Based on your experience, if you pushed yourself too hard physically, which of the following symptoms would you experience?' or something like that, as well as asking about delay (and bearing in mind that the amount of delay or the timing of the PEM peak may vary depending on how hard you push things).

I hope that appropriate questions about PEM resulting from cognitive exertion will also be asked.

 

[Invisible Woman]

Based on the last few posts and some extra bits from me :

1. I think they have to allow for people no longer triggering PEM because of self management. This does not imply they have mild ME simply they manage their lives in such a way As to significantly reduce the risk of inducing PEM.

2. For some people the threshold at which PEM is triggered is so low they are in a constant state of PEM. Therefore it may be difficult for them to differentiate it from their normal state.

3. I think they also have to allow for mental exertion triggering PEM. This may be due purely to cognitive tasks. This is certainly true in my case.

4. For some people PEM may by induced by environmental factors - It can be caused by both the type and severity of sensory load. In my own case type of noise and quality of light can be a trigger.

 

[Indigophoton]

In that sense, PEM is a symptom of treating the illness incorrectly,

It's not always optional though: at a severe enough level, just continuing to be alive is enough to trigger it, because there is literally too little energy in the system to ever stabilise/for any significant length of time.

In this kind of case, triggers include sensory input, over which a person may have no control.

For those lucky enough to be able to live within their energy envelopes, that's great, but I think we should be a bit careful of anything that seems to suggest that patients can always fix it, or avoid it.

Perhaps along with a description/definition, we just need to additionally include that PEM puts a hard physical ceiling on patients' functionality, at a level approximately determined by level of severity.

ETA cross-posted with Invisible Woman

 

[Barry]

All great comments, want a stronger like button.

Clarification on ‘trigger’: yes exertion is by far and away the main trigger. However, sometimes things are made worse by environmental factors rather than outright exertion.
Eg having young rambucious (sp?) children come to stay gave me a small crash despite very careful pacing to well below my normal limited safe zone.
NB I think this is part of why sometimes PwME find crashes come unpredictably. (And why I am only mild/moderate fluctuating: I have control of my environment...usually).

That said, it’s cumulative too. Sometimes I think I got away with it (my PEM is 24hrs almost like clockwork) but then do more and it tips the balance. So that’s a problem with the word trigger. Hmmm

Exactly so. When our daughter and grandchildren come to stay, my wife struggles after a while. Our daughter is extremely understanding, and our grandchildren too young to understand. My wife loves getting involved with our grandchildren, getting thoroughly covered in paint and glitter.

Although my wife does do more when family visit, there is one absolutely crucial difference - she cannot pace herself how she has learned to instinctively do. Which means she peaks and crashes more, steadily getting worse. Yet she loves these visits, and our daughter needs them too, so it's a management exercise. Sometimes my wife just has to stay home whilst I take the youngsters out, or our daughter will just do something with her children, whilst my wife rests and I'm at work.

I think that pacing is really about keeping PEM cycles shallow, so the troughs are not too deep - maybe such that they are not particularly obvious. When the pacing goes adrift, the PEM kicks in harder and becomes much more evident.

 

[Diwi9]

• There is a loss of functional capacity and/or stamina. - "functional capacity" seems a bit vague. My muscles remain strong, but become fatigued very quickly. And again, while this is an ME symptom, it's more of an immediate/constant reaction to exertion, not part of PEM

Reduced functional capacity is a big component of PEM for me. Exacerbation of symptoms (physical and cognitive) means that I cannot read, I cannot tolerate sound, I'm in bed...so functionally I'm not showering, I'm not doing the dishes or cooking. It becomes very difficult to perform basic self-care during PEM. My muscles, unlike @Valentijn, do become weaker and I have poor motor control, develop tremor and muscle fasciculations.

 

[Graham]

For those lucky enough to be able to live within their energy envelopes, that's great, but I think we should be a bit careful of anything that seems to suggest that patients can always fix it, or avoid it.

Too true: I always appreciate how lucky I am.

But I have thought of an analogy. Some of us have fair skin, and burn easily in the sun. Some folk have skin so sensitive that virtually any exposure to the sun causes problems. Measuring the size and severity of the burn doesn't reflect the sensitivity of the skin so much as the extent to which a person overdoes things. Similarly (for those of us who can) if we do overdo things, we try not to go too far, so our symptoms are not severe.

Surely the measure of skin sensitivity is how much sun can you take before you suffer, not how badly burnt you were last summer?

Or in our case, how much can you do before you suffer? And for those of you who are virtually unable to avoid payback, the answer to that is very little.

 

[Indigophoton]

Interesting idea for an analogy, @Graham. The degree of sunburn actually is slightly dependent on history of burns, or sun exposure. A degree of tolerance can develop with exposure over time eg, I also burn easily, but not so much on my face and hands now, thanks to years of sun on those areas.

For PEM, history does matter quite a lot. Eventually, the more episodes of PEM, the greater the susceptibility/the faster it happens/the less exertion is needed to make it happen.

Also, the relationship between exertion and degree of PEM varies with severity. The more severe the patient, the worse the PEM for the same amount of activity. i.e, the more badly one is affected, the greater the degree of payback from a given (level of) activity.

The NAM/former IOM definition Simon quotes seems to recognise this,

5. Severity and duration of symptoms that is often out-of-proportion to the type, intensity, frequency, and/or duration of the exertion. For some study participants, even basic activities of daily living like toileting, bathing, dressing, communicating, and reading can trigger PEM.

So I think what you said,

Or in our case, how much can you do before you suffer? And for those of you who are virtually unable to avoid payback, the answer to that is very little.

is a good point, but how much one can do perhaps reflects degree of severity of ME, rather than being a measure of PEM per se.

 

[lansbergen]

is a good point, but how much one can do perhaps reflects degree of severity of ME, rather than being a measure of PEM per se.

In my case flares were much worse when I still could do less.

 

[Graham]

reflects degree of severity of ME, rather than being a measure of PEM

Exactly! I'm expressing my doubt as to whether measuring the intensity of PEM is a worthwhile exercise. All that is needed is to know that it is there. Surely the sensitivity of the triggers is more important.

 

[Sean]

Thank you, Simon, for raising this.

I think the real problem here is that it is still a subjective self-report measure, with no objective testing. Until that changes we are going to continue to playing games with words.

 

[Forbin]

Points I would make (that others might disagree with):

What I consider PEM is always delayed and peaks the following day. Whether this is really 24 hours later, or is simply a matter of something like there having been a sleep interval since the exertion, I'm not sure.

[By an odd coincidence, I wrote the below before I read @Graham's analogy to sunburn above.]

For me, PEM is not, in the main, increased "fatigue." It's feels like some kind of an immune response that makes you feel crappy. You can feel this way with the flu, but you can also feel this way with a severe sunburn (separate from the topical pain). It's primarily "malaise," not fatigue. Oddly, during PEM, my arms and torso feel somewhat "on fire." It's a kind of coarse buzzing, prickly feeling, which, though unpleasant, isn't exactly painful. I'm pretty sure this was also a flu symptom that I had experienced prior to ME. There's also some general, flu-like muscle soreness and a greater resistance to further exertion.

PEM may be difficult for some people to detect early in the illness. I think it can be swamped by other ME symptoms that are more severe in the first year(s) of ME, and patients simply may not try to exert themselves very much during those years.

Also, it's really counter-intuitive to feel bad after a delay of 24 hours after exertion. It may take quite some time before people even make that connection, if ever. I only noticed it about three years in, and I hesitated to mention to others because I thought it might make me sound nuts. I wouldn't even discover that PEM had a name for another 25 years.

 

[Trish]

I concur with the view that PEM is much better described as malaise rather than fatigue.

A day or 2 after tipping over my physical activity limit I feel much sicker - as though I've gone down with an infection - headache, nausea, extreme weakness, sometimes sort throat, greatly increased pain. This lasts at least a day or 2, weeks if I've badly overdone activity or tried to push through the start of PEM.

Fatigue and tiredness are the least of my worries during PEM. I feel horribly ill and usually have to stay in bed for the duration.

• Dead, heavy feeling after starting to exercise.
• Next day soreness or fatigue after non-strenuous, everyday activities.
• Mentally tired after the slightest effort.
• Minimum exercise makes you physically tired.
• Physically drained or sick after mild activity.

These suggested descriptors do not begin to address what I'm describing. Apart from the last one, they sound much more like the sort of things I would have said if I was healthy but unfit and lacking sleep.

• A flare of some or all of an individual’s symptoms,
• with an immediate or delayed onset and
• with prolonged recovery.
• Severity and duration of symptoms are out of proportion to the initial trigger.
• There is a loss of functional capacity and/or stamina.

This comes much closer to my experience.
I would suggest they could be translated into descriptors that patients could rate. Something like:

A significant relapse of one or more of your symptoms such as pain, weakness, sore throat, headache or a feeling of physical malaise after a small increase in mental or physical activity.

A delay between the activity and the onset of this relapse of hours or a day or two.

Prolonged recovery from this relapse that may take days or weeks.

Reduced stamina and ability to function during the relapse.

I agree that any attempt to quantify the severity of PEM is pointless, as it's very subjective, and varies according to by how much you have exceeded your threshold. It is the existence of PEM in the patient that is important in order to clarify diagnosis.

 

[Sasha]

I agree that any attempt to quantify the severity of PEM is pointless, as it's very subjective, and varies according to by how much you have exceeded your threshold. It is the existence of PEM in the patient that is important in order to clarify diagnosis.

I think that this is hugely important.