Functional cognitive disorder: dementia’s blind spot, 2020, Stone, Edwards et al

[Andy]

More empire building by the FND crew.

An increasing proportion of cognitive difficulties are recognized to have a functional cause, the chief clinical indicator of which is internal inconsistency. When these symptoms are impairing or distressing, and not better explained by other disorders, this can be conceptualized as a cognitive variant of functional neurological disorder, termed functional cognitive disorder (FCD).

FCD is likely very common in clinical practice but may be under-diagnosed. Clinicians in many settings make liberal use of the descriptive term mild cognitive impairment (MCI) for those with cognitive difficulties not impairing enough to qualify as dementia. However, MCI is an aetiology-neutral description, which therefore includes patients with a wide range of underlying causes. Consequently, a proportion of MCI cases are due to non-neurodegenerative processes, including FCD. Indeed, significant numbers of patients diagnosed with MCI do not ‘convert’ to dementia.

The lack of diagnostic specificity for MCI ‘non-progressors’ is a weakness inherent in framing MCI primarily within a deterministic neurodegenerative pathway. It is recognized that depression, anxiety and behavioural changes can represent a prodrome to neurodegeneration; empirical data are required to explore whether the same might hold for subsets of individuals with FCD. Clinicians and researchers can improve study efficacy and patient outcomes by viewing MCI as a descriptive term with a wide differential diagnosis, including potentially reversible components such as FCD.

We present a preliminary definition of functional neurological disorder–cognitive subtype, explain its position in relation to other cognitive diagnoses and emerging biomarkers, highlight clinical features that can lead to positive diagnosis (as opposed to a diagnosis of exclusion), and red flags that should prompt consideration of alternative diagnoses. In the research setting, positive identifiers of FCD will enhance our recognition of individuals who are not in a neurodegenerative prodrome, while greater use of this diagnosis in clinical practice will facilitate personalised interventions.

Paywall, https://academic.oup.com/brain/advance-article-abstract/doi/10.1093/brain/awaa224/5892366
Sci hub, https://sci-hub.tw/10.1093/brain/awaa224

 

[Sean]

An increasing proportion of cognitive difficulties are recognized to have a functional cause, the chief clinical indicator of which is internal inconsistency.

You guys sure you want to go down this road?

 

[Jonathan Edwards]

My mother has major internal inconsistency in her cognitive impairment. She knows who I am but doesn't know who I am. She knows where she lives but still wants to 'go home'. She has no idea there is an epidemic but she knows that Oxford will soon have a vaccine. And so on.

She has advanced dementia, but of no known cause. (Alzheimer's has no known cause either.)

 

[Arnie Pye]

So now people with Mild Cognitive Impairment or early dementia are going to be told that with CBT they can learn to remember things again, they can get back their word-finding ability, and will get back their logic and reasoning ability?

And if it doesn't work the patient will be assumed to be what? Lazy? Could remember things if they just tried harder? Will remember their vocabulary again and will speak as fluently and logically as they did when they were twenty years younger?

This is absolute rubbish!!!

 

[rvallee]

Complete gibberish.

Clinicians and researchers can improve study efficacy and patient outcomes by viewing MCI as a descriptive term with a wide differential diagnosis, including potentially reversible components such as FCD

Chemo fog is a well-known consequence of chemotherapy. This is what it describes. It is reversible once chemotherapy ends, at least for the most part. Being reversible or not has nothing to do with "conversion disorder". It even has a known cause. So is the mental confusion that is present with nearly all illness. This is all gibberish nonsense.

When these symptoms are impairing or distressing, and not better explained by other disorders, this can be conceptualized as a cognitive variant of functional neurological disorder, termed functional cognitive disorder

Anything can be conceptualized as anything. What kind of ridiculous nonsense is this? You can conceptualize cancer as an astrological phenomenon if you want, by that standard. How is this ridiculous juvenile nonsense worthy of publication? Or funding? Or being taken seriously?

Indeed, significant numbers of patients diagnosed with MCI do not ‘convert’ to dementia.

You can inject people with LPS (?) creating a sickness response and get MCI that does not "convert", whatever is meant here, to dementia. You can do the same by infecting people with the flu virus, as well as several other pathogens. So what? This isn't even clever or arguing anything, it's nothing but a nonsensical word salad by delusional people.

 

[Andy]

Now open access, https://academic.oup.com/brain/article/143/10/2895/5892366

 

[Utsikt]

These criteria came up here:
https://www.s4me.info/threads/funct...sease-2025-cabreira-stone-carson-et-al.45178/

From box 1 about internal inconsistency, a positive sign for FCD:

Internal inconsistency is the ability to perform a task well at certain times, but with significantly impaired ability at other times, particularly when the task is the focus of attention. Therefore, the individual components required to execute the task are intact, but there is difficulty engaging them at the appropriate intensity or duration on demand.

This screams dualism to me. If we ignore that we don’t actually know how brains work and assume that we do: Apparently, only the «components required to execute the task» is physical, and the part that «engage them at the appropriate intensity or duration on demand» isn’t? Because if it was physical, that part not working properly would be just as much of a sign of neurodegeneration as anything else.

 

[bobbler]

Complete gibberish.

Chemo fog is a well-known consequence of chemotherapy. This is what it describes. It is reversible once chemotherapy ends, at least for the most part. Being reversible or not has nothing to do with "conversion disorder". It even has a known cause. So is the mental confusion that is present with nearly all illness. This is all gibberish nonsense.

Anything can be conceptualized as anything. What kind of ridiculous nonsense is this? You can conceptualize cancer as an astrological phenomenon if you want, by that standard. How is this ridiculous juvenile nonsense worthy of publication? Or funding? Or being taken seriously?

You can inject people with LPS (?) creating a sickness response and get MCI that does not "convert", whatever is meant here, to dementia. You can do the same by infecting people with the flu virus, as well as several other pathogens. So what? This isn't even clever or arguing anything, it's nothing but a nonsensical word salad by delusional people.

It's an embarrassing approach to have put down on paper isn't it really, given where eg neurology is at currently with things like CTE in trying to make that diagnosable ante-mortem, and how obvious it turns out to often be post-mortem as not something 'unstructural' or 'functional' .

Is this just signalling that part of an area of medicine has given up on doing medicine or science [toying with whether the word properly is needed or superfluous]. Particularly the lot that has been trying to sell the fact they've buddied up with or 'double-certified' themselves in psychiatry instead of getting on with the glaring gaps to be properly worked out how to be tackled in their day-job subject rather than just pattered-off into pseudo psychoanalytical story that just happens to involve palming people off to be dealt with by another HCP doing CBT etc but don't seem to really open-mindedly check-up on the outcomes for that or indeed be held accountable for them.

 

[bobbler]

These criteria came up here:
https://www.s4me.info/threads/funct...sease-2025-cabreira-stone-carson-et-al.45178/

From box 1 about internal inconsistency, a positive sign for FCD:

This screams dualism to me. If we ignore that we don’t actually know how brains work and assume that we do: Apparently, only the «components required to execute the task» is physical, and the part that «engage them at the appropriate intensity or duration on demand» isn’t? Because if it was physical, that part not working properly would be just as much of a sign of neurodegeneration as anything else.

Hmm I get it.

This phenomena sort of exists for eg motor-related tasks in only very specific conditions where for example it is activities that have tended to be automated eg for example driving, vs making someone tell you out loud what they are about to do in order to drive without being allowed to just not think and get on with it.

I'm not completely sure which particular cognitive only tasks would fall into this bracket on the other hand.

I mean I can have a brainless conversation, but heck it is different to what I would be saying on the same subject if I wasn't exhausted and ill or eg in a well-person distracted or asleep (yes I can hold a conversation when asleep, but only in a predictable reply sense like a chatbot would do). The fact I might then struggle when concentrating and less ill might be more due to realising the implications of why I was being asked x or y and what might be done with the answer.

I'm struggling to think how you can get/compare similar cognitive-level of eg conversation or activity and then test focus vs not focus.

I can see how someone might be too ill if they have a fluctuating condition to answer a certain type of question one day, but better on another. Which is a different thing altogether