Discriminating Myalgic Encephalomyelitis/Chronic Fatigue Syndrome and comorbid conditions using metabolomics in UK Biobank, 2024, Huang et al

So do you think the nervousness precipitated the PEM or did the nervousness create the insomnia and being awake for so long precipitated the PEM?

 

Not speaking for Kitty, but I also get insomnia the night after a day of intense overexertion. Might take like 3-4 hours longer to fall asleep. This is before any real PEM. It just feels kind of like trying to sleep after drinking a coffee.

I guess it's possible less or worse sleep can at least partly cause PEM.

 

If we were to say PEM is caused by energy being expended beyond a certain level then this would make sense.

Patients discuss limiting exertion but what they refer to is limiting exertion they control, most energy is used outside of our control to keep us functioning day-to day. Beyond that, it sounds like sometimes things happen to patients that are beyond their control and burn more energy. Being awake burns more energy than being a sleep, feeling wired or anxious burns more energy than feeling relaxed, etc.

I suspect PEM is often precipitated by burning energy beyond the patient control. If it is fight-flight then the autonomic measurements like HRV could be useful as a predictor of PEM.

 

I don't think it was a big factor, but feeling a bit nervy for the first half hour would probably use up more capacity than usual.

Most of the overstimulation was caused by being in a busy, noisy environment, working my diaphragm hard to blow a woodwind, tapping my feet to the beat, plus travelling and back. It's always hard to sleep when I've overdone things, but music seems a particularly effective way to trigger the wired-but-tired effect.

Usually I just factor that into my pacing, but this looked like disaster-scale PEM—the sort where the level of lymph gland swelling and sore throat suggested I was in for weeks of feeling terrible. Thankfully it turned out I'd picked up Covid.

This makes sense of the pattern and the experience, but maybe we should be careful about accepting it just because it makes sense. Envisaging PEM in terms of energy might not be helpful; I've started using the word capacity instead, to try and break out of that mindset. (Not very successfully so far, if I'm honest.)

We do feel as if we've run out of something when we trigger PEM, but it may have nothing to do with energy. It could be that it just sets off a signal, in the same way that getting infected with Covid set off a chain of consequences.

Fo what it's worth, the only reliable indicator I've found is an after-the-event one. My overnight resting heart rate goes up noticeably during PEM and illness, and not just for the night when I can't sleep. I don't think it's unusual to see a raised RHR during illness, but it's interesting that it happens with PEM too.

 

Yes agreed. Not stuck to the concept of PEM and energy or capacity. It does seem like the most often discussed connection but best to keep the mind open.

 

Slow as a Turtle in. answering.
If getting a red flush would lead to PEM, I would be in deep trouble. It happens to me sevaral times a day, mostly when I use my computer.
I recently measured my oxygen during a flush and it was below 95%, even as low as 92% once.
My brain demanding more blood /oxygen from the rest of my body, by invoking a flush?

Muscle pain even starts during exertion. I had only 1 1/2 minute of aerobic metabolism during my CPET and chronotropic incompetence. The test was stopped by the doc before time was up.
My legs were like rubber bands after the test. I had to lock my knees and hold on to the bike getting off.
That's an immediate reaction building up in the hours afterwards.

 

It took 11 years for Adrienne's illness to be diagnosed. A new computer model could change everything
Source: The Age / The Sydney Morning Herald
Date: March 29, 2025
Author: Broede Carmody and Hannah Kennelly
https://www.theage.com.au/national/victoria/it-took-11-years-for-adrienne-s-illness-to-be-diagnosed-a-new-computer-model-could-change-everything-20250324-p5llz1.html
https://www.smh.com.au/national/victoria/it-took-11-years-for-adrienne-s-illness-to-be-diagnosed-a-new-computer-model-could-change-everything-20250324-p5llz1.html

 

I’m late to the party here but I definitely share a lot of this and I’ve been thinking more about my “wired-tired” experience of PEM. I do feel like I’m running out of something, but I also feel like my adrenaline response is kicking in to keep me going.

I notice that when I have to be out of the house for a doctor’s appointment or something similar, I will feel fine for a bit of time, and then eventually pain, brain fog, and muscle weakness start setting in. It slowly builds and builds until I can finally go home.

Once I actually get home and let myself “switch off,” it feels like the dam breaks. All of a sudden that residual pain takes over my whole body and I can’t even get up from where I collapsed. But I still feel wired, I usually can’t go to sleep easily that first night.

I wonder if it’s mediated by some kind of sustained compensatory adrenaline response. Like I might have a tiny bit of reserve battery when I start the activity, but as soon as that runs out, the backup power kicks in and keeps going until I know that I’m in a place where I can rest from then on. But the backup system was also keeping the pain suppressed, so when that goes offline, you just get some uncontrolled signaling leading to PEM. And if the stress signal doesn’t turn Completely off, that would explain the “wired” feeling.

I could probably tie this into cortisol more eloquently if I had more energy. Interesting that many of us experience these same temporal dynamics, I think it tells us a lot about potential mechanisms.

Edit: I think there’s also a correlation between how long I have to keep going on that “backup” power and how awful the resulting PEM ends up being

 

Having found steroids calmed my body a bit on these things (rather than opposite) and knowing the adrenaline vs cortisol stuff I do before that (I’ve always assumed it was adrenaline keeping me standing through that) before that, I then felt it confirmed to me it is adrenaline/not enough cortisol for ‘that’ (whether ‘that’ of the me type creates an increased need or whatever) .

I also had a car suddenly spin out in front of me on a motorway once (speeding and hit the slipstream as they were about to pass a lorry) . I somehow instinctively did all the right things along the lines of what a regular talking the talk in a pub would say they’d do whilst it all being slow calm and so clear. And the car span several times and just as it was on the spin that if completed would have been in my path he did a pull out (steering into it,power on) and I’d braked enough and I could then fit the first time predict where it was going and moved to the hard shoulder to drive round.
Felt just like when I had to throw myself on a train to get to a very vital medical appointment with severe me and didn’t know I’d make each bit of journey just had to tackle it as I did as I must get there calm and concentrated.

then five minutes down the road I had to pull over as my whole body started shaking as the after adrenaline.

now me/cfs over exertion (I now call it ‘using momentum’ when you call on forcing to get yourself home my hook or crook) wasn’t quite that five minutes but I could also feel the relationship of it. And certainly the when you are in PEM but in big pain but can’t sleep yet most exhausted head and body buzzing. Probably because my body had resort to adrenaline to do the ‘high stress’ (I’m being sarcy to bps here) task of crawling home and up to bed well after I’d run beyond empty.

I don’t know if everyone is the same though

 

A trivial but recent (and common) example. The effort of sitting up and trimming my hair or beard with clippers. Sometimes it goes okay, other times it’s too much and a few hours later I can feel the heaviness and aching spreading through my whole body, not just arms or core that had been used. Then that night, I just can’t get to sleep and don’t sleep as well. Not overthinking or anything just not restful.

It may only last a night or a few nights. It’s quite mild compared to the more unpleasant stuff (which then has more noticeable cardiovascular elements etc) from greater activity, but I find it a good example of the tired but wired from a purely physical activity rather than other activities which may involve cognitive overstimulation and or psychological elements.