Functional neurological disorder and placebo and nocebo effects: shared mechanisms, 2022, Fiorio, Edwards et al

Abstract

Functional neurological disorder (FND) is characterized by neurological symptoms that cannot be explained by a structural neurological cause. Among the different aetiological models that have been proposed for FND, of note is the Bayesian predictive coding model, which posits that perception relies on top-down cortical predictions (priors) to infer the source of incoming sensory information. This model can also apply to non-pathological experiences, such as placebo and nocebo effects, wherein sensory information is shaped by prior expectations and learning. To date, most studies of the relationship between placebo and nocebo effects and FND have focused on the use of placebos for diagnosis and treatment of FND. Here, we propose that this relationship might go beyond diagnosis and therapy. We develop a framework in which shared cognitive, personality and neuroanatomical factors justify the consideration of a deeper link between FND and placebo and nocebo effects. This new perspective might offer guidance for clarification of the pathogenesis of FND and for the identification of potential biomarkers and therapeutic targets.

Paywall, https://www.nature.com/articles/s41582-022-00711-z

 

The old model is dead. Long live the old model with the same old hat.

 

I know someone old who was nearly carted off to a residential home for dementia when it was sodium deficiency. The latter is far from a zebra - so I'm not sure that phrase does much good in medicine when it can be extrapolated by some to excuse not looking at basic differential diagnoses (which I think is what BPS and too many other 'types' in the professions do), or just assuming and not being interested enough to look at all (and assuming psych).

Horrific when you think about it. A week of sorting out the salt and fluid and they were sorted. Even if you were a hard-headed pillock only talking or being sold finances no logic says had they been carted off it wouldn't have been catastropic in all ways.

That's what this reminds me of. Starts making me think this is about costcodes or phobia of whatever stops them involving other specialties.

So if the symptoms go through the brain at some point, but it isn't one of a small list of large structural issues (don't believe they are using the more intricate ones EDIT* scanning techniques either), they think 'personality'. Their 'hardware/software' nonsense they've kidded themselves of (I can only assume to try and change their own place in the hierarchy because it ain't fact) has made them forget their science where the brain is just a part of the HPA and other axes and so many other bits - all of which are impacted by 'balances' or something 'hardware' in the body. As if diabetes can't cause coma, other serious conditions with crises can't cause seizures.

I can't help but think when I read this type of article that it's people focusing on looking for and embedding the tropes that cause this waste of life and money first ie before other likelihoods are excluded - medicine by presumption.


The real begging question is: Where has this 'big' condition suddenly come from out of nowhere? Which makes me think missed diagnoses from changes in system approach and structure, or a 'split-off' from a previous category where different features have recently been spotted. Or do they have some event or chemical or something it is connected to?

Is this a paper-based condition effectively being 'created' from all this 'modelling' based on cognitive factors rather than patients presenting and being investigated thoroughly?

The placebo/nocebo thing really concerns me as a basis for 'going beyond' - to me I think it's part delusion of doctors that it is 'patients' minds' rather than 'trial effects' (including their own influence and behaviour) I find it shocking they can't see is behind that. To try and base whole sectors of medicine on this 'fake truism'... I'd need a philosopher to play out the logic on that thinking pattern going to an extreme but it is a concerning lack of self-awareness to me.

 

This "Bayesian predictive coding model" has been previously discussed here, it is basically pseudo-science at this point because it not only has no empirical basis, it is likely contradictory of actual findings.

 

You forgot to add metabolic and genetic processes can cause neurological problems.
Mitochondrial disease is one and the other is lysosomal storage disease such as adrenoleukodystrophy and muscular dystrophy can cause neurological problems