Moved post
I've always interpreted the variations on "PEM is thought to be unique to ME" as:
1) a defensive response to the wilful or ignorant confounding of PEM with standard exertion intolerance, and
2) as meaning it hasn't been found yet in any other disease, apart from Long Covid now, where we've looked - but of course we've barely started looking, least of all in rare diseases.
The most important thing to my mind is that PEM is a core feature of ME, whether unique or not, and the biggest danger now that more people are using the term PEM outside ME is that it simply becomes a synonym for the more common exertion intolerance and the strange pattern of PEM gets lost in that.
It would definitely be good if PEM was looked for in other diseases (as long as we can trust the people looking that they can tell the difference between PEM and exertion intolerance, not a given), you never know what you might learn in the process.
Agree on all this. But would use the word distinctive. I think PEM is 'exertion-intolerance' but not vice-versa? The variations across (and within I have different PEM for different things) ME-PEM probably also give clues e.g. the sleep and immuney type bits. It's also at a patient level a reflection of the cloth-earedness they've come across if they've had it a long time, requiring a 'stop. listen. it's not what you assume' phrase (describe PEM perfectly in good detail with proper nuanced scientific curiosity and it gets deliberately misheard, received or mislabelled as fatigue or some generic which always seemed a disappointment - 'brain fog' is now the latest one for that).
There is the separate issue of which illnesses are allowed a 'sicknote' from the 'treat with exercise' ideology NHS has developed. I think the 'unique' is to be polite re: the unfit presumption, and precise for tact e.g. "I'm not saying your physio changes over the years is wholesale rubbish, just that it doesn't work for me". And yes, getting rid of PEM and muddying the understanding of it, is I think key for the BPS - just read one of the FOI releases (from the 'less rehearsed' psychiatrist) saying 'this is a guideline for PEM/PESE not ME/CFS'. It (ME guideline)
should be a guideline for this, defined properly. So be careful somewhat (tendency to just have 'generic PEM clinics').
Point 2 in summary: I agree that a PEM/PESE-based stream of research wouldn't be a bad one to develop (at least it steps it out of the fatigue clinics and measures), it is obviously medical indicating something medical and scientific and a big clue for other things. Could help other conditions. Might be different types even within the few illnesses like Long Covid where the cause is the same. Can't really separate out who has what anymore either, as per below, and comborbidities, but also I suspect distinctions existing today might be looked back on as arbitrary in certain areas if new genetic/immune-focused areas get developed in medicine.
Go at it from a 'if all these people have it with various different other body-part issues and symptoms what could be the commonality underlying it' and find out types of PEM/PESE and underlying pathology/process
across other diagnoses?
More detail on why:
ME/CFS diagnosis is a dumping pot of generally untreateds. We have 3 different illnesses/cohorts for that term: those registered as having it at GP have high misdiagnosis rate (many go on to have other comorbidities or misdiagnoses like RA etc) but most have PEM; scientific research -
only ME/CFS
with PEM but more mild-moderate band (due to logistics); BPS research cohort
mildly fatigued people
without PEM that they
report in their results - 'Krypton Factor filtering/treatment' + not reporting drop-outs whittles any out. The latter are sourced from their increasingly 'bums on seats' supply-led 'fatigue clinics'.
The GP 'cohort' is iller than both research ones and almost the opposite of the BPS reported ones, and seen and investigated less thanks to the old hypochondria guidelines. That bucket isn't 'clean' and has all sorts of comorbidities likely untreated too as well as badly-managed longstanding ME (which is different). Noone has gone through that bucket to sort them out re: what they can actually treat, help with or get to the bottom of.
From what I hear of friends who have been abroad and come back with serious non-ME conditions/generational comparisons it seems in UK the 'access' to diagnosis for other illnesses has a higher bar only possible once a lot of damage has been done ie those who'd been under treatment for years abroad as pretty bad told they wouldn't get a UK diagnosis until they significantly degraded further (Nice guidelines covering private too). Are those who never went abroad also in this pot? So do they actually know much about 'early' illnesses of those kinds anyway to 'bottom up' that? Is this actually a 'PEM/PESE pot' as it is, and the answers to that is an edict telling people to investigate us all properly?