United Kingdom: Dr Suzanne O’Sullivan (BPS neurologist)

No worries! Thread on the paper and the reply here:
https://www.s4me.info/threads/muscl...vugt-appelman-et-al.34994/page-11#post-586938

 

Many thousands of scientists disagree with you on this, though.

Pain is a warning system but a bit of a primitive one. It's job is to warn you are are in danger, so in this case you move your hand. It's more important to move the hand and avoid harm than it is to figure out that it's a fake hand being hurt. In the moment, the brain fully believes it is your hand being hurt and that action is needed.

Fatigue is also used by the brain to protect you. It can be used to remove you from an environment to keep you safe in all sorts of circumstances. We understand this pretty comprehensively these days but one example is thanks to studying runners in marathons. 'The brain uses the symptoms of fatigue as key regulators to insure that the exercise is completed before harm develops.' The brain predicts when harm might arise (for example you are running out of fuel) and makes you tired to get you to stop. See here: 10.3389/fphys.2012.00082 (Noakes TD. Fatigue is a Brain-Derived Emotion that Regulates the Exercise Behavior to Ensure the Protection of Whole Body Homeostasis. Front Physiol. 2012 or Lekander's book). The fatigue kicks in before your fuel actually runs out or another harm occurs. It is protective.

Ergo, beliefs can cause the symptom of fatigue in M.E if part of your brain feels under threat. It is a belief that is unknown to you, but it still exists within your brain which is trying to juggle all sorts of sensory input.

 

Again, you are trying to explain disease through normality. That will not get you anywhere.

 

Except in the case of M.E, there is (as yet) no objective evidence of actual disease. There is no biomarker, right? Real symptoms, yes. Disease, no.

 

Apologies, I could have made a more general statement.

You’re trying to explain deviations from normality through normality.

 

Thanks

 

A key aspect in these experiments is although there is flinching behaviour, the participants don't actually feel pain when the fake hands are "hurt".

It is ONLY the proprioception system that is being fooled and it can be fooled because it is a system that requires real-time predictions (afferent feedback is too slow) and uses a variety of inputs to do so.

Pain and fatigue on the other hand do not require real-time predictions: there is no predictive coding and hence there is no way to fool the brain.

I have commented many times on Noakes theory, but to summarise, there is still zero evidence that the brain has any sort of predictive model of whole body homeostasis. Since 2012 there is now strong evidence for a very different theory, suggesting that Noakes was mostly wrong.

Fatigue is NOT a signal to stop and to say it is goes against observation of normal human behaviour. People can literally run themselves to death, but fatigue is a "slow down" signal, not a stop signal and while it was not well understood in 2012, we now know what causes central fatigue - stimulation of metabolic sensing peripheral afferents.

"Fatigue‐related group III/IV muscle afferent feedback facilitates intracortical inhibition during locomotor exercise"
https://pmc.ncbi.nlm.nih.gov/articles/PMC6166070/

"Spinal μ-opioid receptor-sensitive lower limb muscle afferents determine corticospinal responsiveness and promote central fatigue in upper limb muscle"
https://physoc.onlinelibrary.wiley.com/doi/abs/10.1113/jphysiol.2014.275438

So we know the mechanisms for the phenomena Noakes was trying to explain (central fatigue) and that study (along with related studies) falsifies much of his hypothesis.

There is ZERO evidence of that. Beliefs can effect reporting of symptoms, beliefs can effect behavioural and emotional responses to fatigue, but they cannot CAUSE fatigue. We know because we have explicitly done experiments in humans that show how we can block the sense of fatigue.

 

Revisiting "The Sleeping Beauties", it's clear O'Sullivan doesn't care about letting the truth get in the way of a good story.

I found this story interesting:
https://en.wikipedia.org/wiki/Sleeping_sickness_of_Kalachi,_Kazakhstan

Something in the region of 180 people were effected by a mysterious sleeping illness which appeared a lot like carbon monoxide poisioning, and many residents did in fact have high Carboxyhemoglobin levels, such that the government evacuated everyone. People moved out and were never affected ever again, suggesting it wasn't mass hysteria but was in fact environmental. But further investigation, an epidemiologist found that everyone effected had purchased water from one man - who pumped it out of the ground near an abandoned mine - suggesting water contamination was the cause.

 

But 2 day CPET worsening is a sign not a symptom, and the same could be said of the Dutch muscle study results for long Covid. Decon. accounts for neither. How many among ME symptomatics show these signs is another matter.
How the 2 day state of anti-tarining is arrived at , whether some alarm signal turns the body off whether the alarm (if any) is related to current biophysical states , redox imbalance or sth psychological or a mix I do not know but the auld "no disease" in any case does not equate to no sign of physical dysfunction at least in those with 2 day anti-training. And at the point of perception of fatigue on 2nd day what is being perceived is biophysically grounded.