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

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.

 

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

 

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

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.

 

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.