Functional Neurological Disorder (FND) - articles, social media and discussion

Perhaps there are some parallels in the recognition and development of imaging findings in schizophrenia and ME & FND.

With first-onset of psychosis the psychiatrist looks for evidence to suggest an "organic cause", eg a brain tumour. A simple example is the idea that while auditory hallucinations would be expected near 100% in psychosis, visual hallucinations were less common and suggested the psychosis might be secondary — The association between visual hallucinations and secondary psychosis: a systematic review and meta-analysis (2023, Cognitive Neuropsychiatry)

But for many years most of the time patients either didn't get neuroimaging because the clinical exam showed nothing focal to warrant it or got something fairly basic like a non-contrast CT head to look for something like an obvious tumour or raised intracranial pressure. Usually nothing was found and essentially the studies would be reported as normal. This reduced the incentive to do neuroimaging in these patients because the pickup rate was so very low. When MRI started becoming clinically available there was significant resource constraint and patients whose CTs were nearly always normal anyway were not prioritised compared to something like MS which did show things. Now MRI is much more available as a clinical routine and its capabilities are expanding. It's only in the last few years that the field of psychoradiology has started. (This term was to differentiate it from neuroradiology though I suspect ultimately the Venn diagram will overlap much more as we learn more.)

So, finding nothing -> don't look hard -> finding nothing (and repeat)

Then some people do decide to look a bit harder and start to find things or there's a serendipitous observation, which leads to:

finding something -> look harder -> finding something more and more often (and repeat).

For FND in particular, but probably applying in some measure to ME, there has been / continues to be the added issue that the aetiologic hypothesis resulted in a specifically mandated do not look with imaging and other clinical tests.

 

Lots of people on the Small Fibre Neuropathy (SFN) Facebook group I’m part of have received an FND diagnosis at some point in their journey.

Some of these people have got confirmed SFN and are recounting this earlier phase, some are still searching for proof they have SFN - but all have SFN symptoms.

Some got told they had FND after having some very minimal testing. Some even before they had any real testing. Some got it after a bunch of tests - but crucially not ones that could detect SFN.

My point is that these people are presenting with symptoms of SFN or symptoms of SFN plus autonomic dysfunction, which is a subset of SFN whereby the damage to the small fibres in question has extended into the autonomic nervous system.

SFN is a mostly lot of sensory symptoms, like pains and numbness. SFN with Autonomic dysfunction is a wider array of possible symptoms because the autonomic system controls so many parts of the body from sweating, to saliva, to swallowing and so on.

All of this - all of these wild varied symptoms which I’ve not listed beyond the basics - can all somehow be taken to be FND.

I was told I had FND by multiple neurologists. With varied levels of testing, but hardly anything that could ever be called comprehensive. But I didn’t get any tests done that looked at my sensory nerves - the small ones.

Despite that I could be safely diagnosed with my complaints about my body being numb and my feet exploding with pain when bumping something just being dismissed as ‘functional’.

But there wasn’t a problem with my software. I wasn’t suffering with repressed trauma. Something, some unknown agent, had laid waste to my small nerve fibres. Something had blow-torched away my ability to feel normal sensations in my skin - a lot of the small nerves were simply gone. Simple physical proof; undeniable evidence of the destroyed machinery of touch sensation was sitting out of sight in my skin for all those years.

This couldn’t be known, couldn’t be proven, until they actually looked at those nerves. Not just the large nerves, not just with basic crude first-order tests.

You can’t quantify something you never bothered to try and measure. Despite that I got an FND diagnosis 3-4 times from neurologists.
Neurologists working off a model that tells them there is a thing called FND and it has a massive array of neurological-type symptoms. And that if they suspect FND that they should diagnose it confidently, that they should resist patient hostility, that they should convince the patient, and that they should cease further testing (!!!).

In theory FND should be diagnosed after ruling out physical disease. In practice, given the wide range of possible symptoms ascribed to it - from cognitive to sensory to motor - FND is diagnosed at the whim of the neurologist when they feel some vague threshold has been crossed.

You can take your pick of any of the long list of said symptoms your patient might be suffering from, do minimal/some testing, take even one negative test as ‘proof’ that you just absolutely can’t find anything physically wrong (and there’s nothing you could conceivably find wrong, even if there’s 20 more tests you could reasonably do) and diagnose the patient with FND.

Then you write it down, record it as FND, it goes on the statistics, you tell yourself you’ve nailed another diagnosis, you go onto to tell your neurology interns how many FND cases you see, you go to conferences and talk about how common FND is and so on.

I don’t know what else to say except: the map is not the territory.

I’ve kept thinking about that concept again and again and again over the years through the start of my symptoms to my eventual actual diagnosis which was based on actual physical evidence and not theories about software/hardware analogies.

 

The map is not the territory. That line always comes back to mind for me.

You don’t know the land by looking at a map of it. Doctors need to understand what they are seeing and what they are not.

Doctors are not going to be able to practice good medicine by looking at maps (particularly outdated ones) or looking at one corner of a map and going “I’ll just imagine the rest of it and sketch that out”.

They can’t rely on basic heuristics all the time, they need to really do the work to understand what’s going on. They need to get out on the land, and walk it.

I guess, to extend the metaphor, they would have to believe that there is a need to even see the land for themselves, by believing what their patients tell them in the first instance.

 

There are so many great comments here. I do now think there are a group of patients, who after an extensive workup have certain common issues and still have no clear explanation for their neurological symptoms. It makes sense to label these patients so that do not receive completely unwarranted treatments or tests and perhaps have some understanding that these symptoms are not currently life threatening.

However, as has been pointed out, with such a diagnostic label there is much potential for harm. From a patient perspective, if I were in the position of determining who receives a FND diagnosis I would make sure they fulfill the following criteria:

- That an extensive work-up to rule out other conditions is actually performed.
- That the rule in signs and symptoms are present and do not better fit with another diagnosis.
- That the diagnosis does not prevent the patient from receiving any follow up diagnostic testing, ensuring another condition is not present at any later point.
- That if another condition is found, it is appropriately treated and the FND label removed
- That the patient understands that FND only means that we do not know the cause of their condition, which must be caused by some unknown biological pathology.
- That the patient is told their symptoms are real and that there is no evidence to suggest that the cause is some psychological issue or trauma.
- That treatments are only offered to the patient if they understand that we do not have proof of their efficacy.
- That any treatment failure is not blamed on the patient's effort or belief in its effectiveness, but on the treatment itself.
- That the FND diagnosis does not prevent the patient from receiving care for any other separate issue.
- That the FND diagnosis actually improves the overall life of the patient and does not lead to rejection by family and friends.
- That an apology (and potential monetary punishments) are issued in any case where an inappropriate diagnosis was made.

A failure to do any one of these things can lead to potential harm. I would also speculate that the vast majority of clinicians that commonly diagnose FND do not follow all of these criteria. Because these things are not happening, I would argue the harms caused by the FND label outweigh its current usefulness.

I also think that the FND label has likely hindered research efforts. If it were the case that FND was seen as an unsolved problem, then, I would hope that it would receive more biological mechanistic research. However, as is currently the case, there is a strong push to suggest that we know the issue is to do with brain software and is not deadly, so we don't need to keep searching for the specific issue within the brain. I think this is misguided and that research into this condition would be better off if the FND label was not used and it was instead treated as an unknown condition with some hard to figure out biological pathology.

 

It's Mr Bloggs in fact and I know him well and he is very happy.

 

I agree in principle and do not underestimate the harms.

The only problem is that there is no 'zero' harmless option available to the community as of now. The 'harms of the FND label' have to be interpreted as 'how much more harm you get with the FND label than with X' where we have to know what X would be. It might seem simple that we just abandon the FND label. But everyone knows that you just get a whack-a-mole situation with another term coming up. The problem is not the term but the mind-set of many medical professionals. Suggest a way to change that mindset X and we are home and dry but that is not a reality. The fight is against a state of mind, not so much an acronym.

 

I am certainly in agreement on that. Any replacement term for FND would inherit the baggage of the prior labels, just like FDN has connotations of conversion disorder. Ultimately the only way to change the mindset of doctors is more research to understand the underlying mechanisms and provide treatments. Once we know what the issue actually is, those that continue to advocate for false ideas will get pushed out of the field. I also don't think there is any harm in trying to educate doctors about the harms and limitations of the FND diagnosis but I too am skeptical that this will actually be effective. Its the same situation with ME/CFS but having to sit around and wait for the research sucks.

 

If it was really just down to keeping a job or having a drink in the pub why not just stick to a diagnosis of 'conversion disorder' ? This would also be covered as a disability and adjustments made at work.

They could use 'conversion disorder' and people at the pub may be equally clueless as to what this means.

Using FND doesn't protect them any further does it? If someone at work or the the pub does a Google search it shows the link to the old names anyway.

 

That sounds like mindset-acronym dualism

The term "functional neurological disorder" was chosen as a replacement for conversion disorder or hysteria that was acceptable to patients. I think that the term does reinforce the mindset though because it implicitly expands to "functional-but-nothing-actually-structural-or-progressive neurological disorder". That's where much of the smiling and winking is occurring.

Stone, Carson, Sharpe et al. wrote in What should we say to patients with symptoms unexplained by disease? The “number needed to offend” (2002, BMJ) —

Referencing ‘Hysteria’, ‘Functional' or ‘Psychogenic’? a Survey of British Neurologists’ Preferences (1991, Journal of the Royal Society of Medicine) —

 

I agree that separating ME/CFS from FND is very important. Both for patients and to make sure research doesn't get mixed up and reduce the likelihood of getting useful findings. It is a difficult thing to do with some of these FND practitioners handing out FND diagnosis willy-nilly. Because we aren't going to change those people's minds, I think the only real solution is to try make sure patients understand who the ME/CFS and FND labels apply to so they can work out if they have been miscatagorized. If someone has PEM/exercise intolerance then they certainly don't have FND and should reject that diagnosis. I think if you better fit into any other category then an FND is inappropriate.

In one of my pervious posts on this thread I suggested idiopathic neurological disorder. Even though I am sure this would inherit some of the FND/conversion disorder baggage, it does seem like a more neutral term. If I could chose, I would certainly pick the term idiopathic neurological disorder over FND. The issue with this is in the practicality of changing the name of a medical diagnosis. People, especially some medical professionals are quite stubborn, and it seems like an almost impossible task. To me, the introduction of the term FND appears to be a rebranding effort by doctors who believe in the conversion disorder story to make it more palatable. I have a hard time seeing why they would make the switch to a term like idiopathic neurological disorder which would weaken their software claim.

 

A historical note. This sentence is from a letter written by Stone and our friend Sharpe in 2003:

"It remains the case that as many as one-third of the patients seen by clinical neurologists have symptoms that are better explained by neurosis than by neurological disease."

That's where he was 21 years ago. Do he and Sharpe still believe that, and is all the talk of "functional" just bullshit? Or has he disavowed that view and really changed his mind that "functional" means something other than "neurosis"?

 

But it could be simpler than that. Doctors could say there are a lot of things medicine doesn't yet understand, and this is one of them.

Why is there one list of things where it's acceptable to admit lack of knowledge, and another where a story has to be concocted because it's not?

 

I find it interesting that you see this 1/3 figure being used by some (sorry, can't come up with other names, am shattered, but there was an originally-Irish-but-working-in-UK doctor who wrote a book with a chapter on ME/CFS and case studies of, among other things, functional blindness, who used the same 1/3 figure).

In the hospital where I worked, the proportion the neurologists used was 1/6. Quite a difference. The neurologist I heard say that, many times over the few years I worked there, was considered an exceptional diagnostician.

 

I wish they could be a little more humble. But I think a lot of these people are actually convinced they do know the answer. People become convinced of all sorts of things for bad reasons and it can be very hard to change their minds.

Just think about all the terrible explanations that humans have come up with over the last few thousand years. At one point, instead of admitting we don't know what causes lightning we come up with stories about a guy who lives on Mt. Olympus and throws bolts when he is angry. I think there is probably some survival advantage to thinking in this way and so it becomes a critical part of how humans operate. We really don't like the uncertainty of not knowing something. The only reliable way to overcome this is with evidence and understanding how the world actually works.

It is also very hard to admit you were wrong. There are social, financial and personal costs for doing so. And for these people that have built their careers on harmful ideas they will fight until there is no way they can have a tenable position.

 

I think there is a significant difference. 'Conversion disorder' explicitly describes an illness in which your leg gives way because you cannot get rid of the bad thoughts due to being bullied by your elder sister when you were four. Whether or not all the mates in the pub know that, some probably will and the rest can look it up. FND means that your leg gives way because of some dysfunction in the brain. Nobody will have heard of it but they can be told that if they ask. If you look it up you will find things like the bits Hutan found that indicate that this sort of illness in the past has been considered to be due to bad thoughts due to... but it isn't now defined as such.

Just as it doesn't matter to Hannah that the engineers have this daft idea that there are green men in the fridge it needn't matter that at least a good number of doctors think FND is bad thoughts...

Keeping your end up in social situations is often just a matter of having some words that defuse a challenge. 'FND' sounds medical and if people ask Mr Bloggs can explain what he has been told about brain dysfunction. Nobody is going to ask 'so why is it called conversion disorder'?

 

I don't think it is as simple as that. The 'functional' term was introduced widely in medicine to cover problems without an identifiable structural cause. Many physicians found it useful to cover patients they thought had a psychological basis but the term was also used by physicians who had no commitment to psychogenesis - like myself. The neurologists took it on and equally there would have been neurologists who thought the problems it covered were psychogenic and others who were less sure or disagreed. Nearly always in conversation with patients it was used with psychogenic connotation although I realise that some would recommend psychotherapists drag the patient through 'understanding' that it is.

It is very unfortunately that the term was, at least originally, deliberately designed to have multiple meanings. But I am not disagreeing that it is a bad term in many ways. Just that I am not clear that anyone has any better suggestions.

Idiopathic does not fit because a lot of idiopathic conditions have major structural change.
Rheumatoid arthritis is idiopathic - perhaps the most beautiful example. It dissolves away your bones.

 

No doubt he still thinks the same. But physicians of all stripes find it useful to use 'functional' to mean all shades of things. And of course if you are biopsychosocial like Sharpe he would deny that it could possibly mean psychological alone. It would have to mean a bit of bio and a bit of psycho and so on - whatever is convenient at the time.

 

Oh for sure, but the state of mind is currently identified by this label, it's what on the box. Same as when we're talking about some dude named Steve who is doing bad things, we call him Steve, not "he who does bad things because of his state of mind". It's mostly a MD label, rather than a patient one.

The overarching label is really psychosomatic, but the ideology has invented dozens of acronyms, many of which go in and out of fashion over the years, and FND is the latest fashion. We can say all the same things about SSD and CSS and somatoform this and persistent that because they all fundamentally point to the same state of mind. The same applies to any future acronym or label they may invent in the future.

No one has any issues with the label. It's the ideas underneath that are wrong, and we know that part of the ideology has settled on this particular label precisely because it's the one that most easily fools people into thinking they're agreeing to something they don't actually agree with. Which is something that is openly admitted in the literature.

And even when it comes to MDs who do know better, that they choose to allow this at best makes them bystanders to a disaster, which is hardly any better. There's a good quote about this that is usually about dictators but applies just as well here, one that is easily adapted to the situation: the only thing necessary for the triumph of harm is for good doctors to do nothing. There is definitely nothing good about choosing to do nothing in the face of people being unjustly harmed.