Fear conditioning as a pathogenic mechanism in the postural tachycardia syndrome, Norcliffe-Kaufmann et al, 2022

Authors’ reply to Tuller et al.

Extinguishing fear conditioning has already been tried. In fact it’s been the cornerstone of treatment of these patients for decades (CBT, GET) and it hasn’t worked.

Another letter pointed out that most patients have at some point been told their illness is psychiatric and many received psychiatric treatment with no success.

 

Wow. I can't wait for their next paper, "Everytime we turn on a blue light, we gave people an electric shock. These people have developed, for some reason, a fear of blue lights being turned on. If we convince them not to fear what happens when a blue light is turned on, this will mean they are invulnerable to electric shocks!".

 

more or less, yes. How do you "extinguish" the normal response when you know you're going to undergo an unpleasant experience? It's a ridiculous statement. There is zero evidence that "extinguishing fear conditioning," if it were even possible, would have any effect on anything.

 

They also fail to note that conditioning requires quite a lot of closely repeated occurences of the 'nasty outcome' immediately following the stimulus. So it can't have been Pavlovian from numerous tilt tables - as noone would be signed off to do them daily just for safety reasons (as well as there being no point). And for it to apparently have been 'Pavlovian' then it would have required people to have had awful outcomes repeatedly and consistently from standing many times over in many consecutive, close-together situations, over a prolonged period of time.

EDIT: Here is a link: https://www.simplypsychology.org/classical-conditioning.html
Note that also the conditioned response would mellow if the symptoms reduced (ie POTS became better) because it would be stand up -> don't feel ill being repeated, even if there is a 'stress' in the middle. The idea that the stress continues when the POTS symptoms don't for much longer is suggesting a whole different ball game.

Ergo if you don't have POTS in the first place that isn't possible (hence not present in controls) - and if you have POTS that is the cause - and if someone anticipates that is because wherever you are you need to be on the lookout for safe landing spots.

How can someone get away with hurting patients for the sake of it, just to pretend the fact their stress went through the roof proves anything. Tell someone you are going to put them in a diabetic crisis by injecting with too much insulin and the ones who know what that means because they've been in one and know how dangerous it is will probably understandably show this too. Doesn't mean ethics should sign it off. And puts big red flags on ethics boards as to why this illness has been signed off for 'antagonise for no good means, but for quite malign purposes (if we are being frank)'.

What has the world come to on all this - it's weird

 

I horribly think that they do. It seems contrived of what they can 'get away with doing' that would obviously put someone's heart rate through the roof on a condition - and aren't allowed to do such vile tricks to any other type of patient, as it would seem only culture issues let this piece of nastiness slip through the ethics board.

Imagine them taking people who have heart issues that are tested by stress-tests that might be awful and someone signing off getting them in vs a bunch of people with no heart issue who've no idea what'll be involved in order to prove 'it's fear-conditioning not the test itself causing stress'. Or doing the X-factor long pauses on cancer check-ups and comparing the heart rate to a group who have never had cancer being made to take a blood test with a 0.001% likelihood and saying the former group were more stressed before it even started proves something. It's just outrageous ethics and idiocy to the point you wonder about missing modules in thinking these things up.

 

Hmm. Many of these conditions that doctors ignore seem to have something in common...

I can't quite put my finger on it....

 

Letter to the editor by Bourne et al. cites an interesting study I had never heard of with much better methodology addressing the same research question (is POTS fear of standing).

Masuki S, Eisenach JH, Johnson CP, et al. Excessive heart rate response to orthostatic stress in postural tachycardia syndrome is not caused by anxiety. J Appl Physiol. 2007;102(3):896-903.

 

I've seen other studies that use LBNP (lower body negative pressure) testing.

This video on Vimeo - Understanding Blood Volume and Hemodynamics in POTS, by Satish Raj - mentions a study that uses it:

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Here's a screen shot showing what the machine looks like:



EDIT: This study showed "improved short-term orthostatic tolerance exhibited by the subjects with POTS following ORS administration. ORS is a convenient, safe, and effective therapy for short-term relief of orthostatic intolerance." [ORS = Oral Rehydration Solution]

https://pubmed.ncbi.nlm.nih.gov/31405524/

 

See Reduced Stroke Volume and Brain Perfusion Drive Postural Hyperventilation in Postural Orthostatic Tachycardia Syndrome (2024, JACC: Basic to Translational Science) —

Note that they replicated findings in a partial animal model. Partial animal model here means no brain above brainstem, no heart, lungs or even blood; instead using artificial blood and pump. So there is categorically no requirement for fear conditioning.