Evaluating case diagnostic criteria for ME/CFS: toward an empirical case definition, 2022, Conroy, Jason et al

[Mithriel]

Not knowing about ME, I worked out PEM by myself (as was said, in milder days) because I would feel particularly sick and ill one day and realise that 3 days earlier I had done more than usual. Once I noticed the pattern I could look out for it.

Repeating myself but I think it is important. To me the problem with PEM is it is like historical diabetes where the name meant "thirst and copious urine being produced". That urine could be tasteless "insipidus" or sweet "mellitus". Once they discovered what caused these two states they discovered they were completely different diseases.

PEM is difficult, if not impossible, to describe because it is simply a way of trying to describe the outward signs and consequences of our pathology. It is a blunt tool, difficult to define but unmistakable when you experience it.

As research finds abnormalities in our metabolism there may be lots of different diseases under ME or a single thing which causes a cascade of problems. As usual only money and the imagination to think where to look will help us.

 

[adambeyoncelowe]

My subjective sense is that sensory hypersensitivities and orthostatic intolerance result in their own specific short term negative responses that is distinct to PEM if exposure is not too long. Recovery from these if exposure is stopped soon enough is quite rapid, and does not seem to have the paradoxical effect of negative symptoms continuing to get worse once exposure has stopped, which often is a feature of PEM.

However that is not to say they do not contribute to triggering PEM if exposure continues. For example accompanying my god daughter on perfume shopping, resulted it headache, dizziness and confusion, that disappeared rapidly once I took myself out of the shop, whereas using a scented soap that leaves a residue on the skin, means having a bath is more likely to trigger PEM than the same exertion but with hypoallergenic shower gell.

A rock band playing on the Green outside my house was by itself a nightmare, but it continuing for four hour resulted in PEM with all the ME symptoms twentyfour hours later.

This interaction between PEM and hypersensitivities/OI also is seen in that when in PEM the threshold for them is considerably lowered.

To clarify, my personal belief is that PEM and hypersensitivities/OI are distinct phenomenon, but interact in that the latter can contribute to triggering PEM and PEM involves lowering the threshold for experiencing the latter.

Yes, that's what I was getting at too. Thank you.

 

[JemPD]

My subjective sense is that sensory hypersensitivities and orthostatic intolerance result in their own specific short term negative responses that is distinct to PEM if exposure is not too long. Recovery from these if exposure is stopped soon enough is quite rapid, and does not seem to have the paradoxical effect of negative symptoms continuing to get worse once exposure has stopped, which often is a feature of PEM.

However that is not to say they do not contribute to triggering PEM if exposure continues. For example accompanying my god daughter on perfume shopping, resulted it headache, dizziness and confusion, that disappeared rapidly once I took myself out of the shop, whereas using a scented soap that leaves a residue on the skin, means having a bath is more likely to trigger PEM than the same exertion but with hypoallergenic shower gell.

A rock band playing on the Green outside my house was by itself a nightmare, but it continuing for four hour resulted in PEM with all the ME symptoms twentyfour hours later.

This interaction between PEM and hypersensitivities/OI also is seen in that when in PEM the threshold for them is considerably lowered.

To clarify, my personal belief is that PEM and hypersensitivities/OI are distinct phenomenon, but interact in that the latter can contribute to triggering PEM and PEM involves lowering the threshold for experiencing the latter.

Thats an absolutely spot on description of my experience but i couldnt have described it so succinctly. thanks you

I agree. You don't need to do any activity at all to know that you have PEM, because you feel ill.

I'd also replace 'unrefreshing sleep' with 'much more difficulty than usual initiating and maintaining sleep'. There's no mention of the wired feeling, the extreme clumsiness, the inability to remember simple words...

It is a blunt tool, difficult to define but unmistakable when you experience it.

Exactly. Its being ill, and the sensation is unmistakable, it's not interchangeable with fatigue/lack of sleep, its specific and it worries me greatly when i read Jason's descriptions, because i dont recognise any of them really.

 

[ahimsa]

E.g., orthostatic triggers could be seen as physical exertion (you are moving, after all)...

I can't follow the whole discussion, and I'm not commenting on the categories (too complicated for me), but I saw this line and was confused.

A big trigger for my orthostatic intolerance is standing still. I can only do this for 4-5 minutes before symptoms start. Sitting upright is also a problem but it takes longer to cause symptoms. Heat is also a trigger and that doesn't involve movement.

So I'm confused by the comment, "you are moving after all." Can you explain a bit more?

Are folks thinking about the typical type of Orthostatic Hypotension which comes immediately after standing up? I don't get this problem, it's a different type of problem, a delayed drop in blood pressure after standing for a while.

I'm probably not describing this very well but hope it makes sense.

 

[Midnattsol]

I can't follow the whole discussion, and I'm not commenting on the categories (too complicated for me), but I saw this line and was confused.

A big trigger for my orthostatic intolerance is standing still. I can only do this for 4-5 minutes before symptoms start. Sitting upright is also a problem but it takes longer to cause symptoms. Heat is also a trigger and that doesn't involve movement.

So I'm confused by the comment, "you are moving after all." Can you explain a bit more?

Are folks thinking about the typical type of Orthostatic Hypotension which comes immediately after standing up? I don't get this problem, it's a different type of problem, a delayed drop in blood pressure after standing for a while.

I'm probably not describing this very well but hope it makes sense.

Standing/sitting still are big triggers for my OI too, although on bad days I also get dizzy right after standing up. I bought some spiky balance pads I stand on when cooking or doing other tasks around the apartment and it seems to make it easier.

 

[Mithriel]

I can't follow the whole discussion, and I'm not commenting on the categories (too complicated for me), but I saw this line and was confused.

A big trigger for my orthostatic intolerance is standing still. I can only do this for 4-5 minutes before symptoms start. Sitting upright is also a problem but it takes longer to cause symptoms. Heat is also a trigger and that doesn't involve movement.

So I'm confused by the comment, "you are moving after all." Can you explain a bit more?

Are folks thinking about the typical type of Orthostatic Hypotension which comes immediately after standing up? I don't get this problem, it's a different type of problem, a delayed drop in blood pressure after standing for a while.

I'm probably not describing this very well but hope it makes sense.

A late answer but this illustrates 2 problems with PEM.

Finding standing still was more difficult than standing and moving was seen as being typical of ME. Nowadays that is called POTS or Dysautonomia or Orthostatic Hypotension but it well be that the root of the problem is something unique to ME that gives similar symptoms of these diseases but is a consequence of ME rather than having them as a primary disease or comorbidity. PEM in other diseases could be the same confusion.

In direct answer to your question, ME symptoms are down to energy needs so while common experience is that standing still is easier than walking that is because most people have an abundance of available energy. When energy is limited the adjustments needed to stay upright cannot be fulfilled without cost.

Why this is needs researched, but I would walk home rather than stand waiting for a bus because it felt as if walking took more energy to start but once my legs set up a pendulum motion it could be maintained as long as needed. When I had kids the energy needed to fold the pram and carry a baby and toddler made the choice easier.