A practical review of functional neurological disorder (FND) for the general physician, Bennett, Stone et al, 2021

[Andy]

We present a practical overview of functional neurological disorder (FND), its epidemiology, assessment and diagnosis, diagnostic pitfalls, treatment, aetiology and mechanism. We present an update on functional limb weakness, tremor, dystonia and other abnormal movements, dissociative seizures, functional cognitive symptoms and urinary retention, and ‘scan-negative’ cauda equina syndrome. The diagnosis of FND should rest on clear positive evidence, typically from a combination of physical signs on examination or the nature of seizures. In treatment of FND, clear communication of the diagnosis and the involvement of the multidisciplinary team is beneficial. We recommend that patients with FND are referred to specialists with expertise in neurological diagnosis. FND is a common presentation in emergency and acute medical settings and there are many practical elements to making a positive diagnosis and communication which are useful for all physicians to be familiar with.

Open access, https://www.rcpjournals.org/content/clinmedicine/21/1/28

 

[Mithriel]

They spend all their time doing overviews which simply push the fact that FND is a proper medical diagnosis like RA or MS. Repetition designed to make other medical people accept it.

Their positive signs, like the drooping lip or the hip abductor test do not fit with any emotional input. Saying that someone once had an epileptic seizure so the brain replicates it when it has a psychological need makes little sense but saying a droop to one side of the mouth does so is beyond any logic.

They may be detecting signs of an unknown disease but there is no need for a psychological component, that is just dogma.

"The diagnosis of FND should rest on clear positive evidence, typically from a combination of physical signs on examination or the nature of seizures."

This statement could stand if they thought FND is caused by demons. Deciding you have a unique set of criteria (not that I think they do!) says nothing about what is causing them and nothing about what can be done to treat them

 

[Hoopoe]

Physicians can be good at classifying diseases based on their observable characteristics. From that angle, FND may be a valid diagnosis if only to indicate that it's not any of the other things that can be similar but different in some important way. The hard part is figuring out what's happening and why.

 

[Mithriel]

There has to be a plausible theory linking the symptoms to the postulated cause and that is the bit where FND falls down.

They simply claim the brain is plastic which just pushes any explanation further back it is not a cause just a fact of biology. Everyone's brain is plastic why do only some people get FND?

Their statements, delivered with great confidence, that the sort of symptoms you get depends on what your brain remembers experiencing in the past (what happens if you had epilepsy and gut symptoms?) are the important things that need proof, not that they happen but how they can happen.

No amount of evidence elsewhere makes up for these holes.

True science would look at alternate theories. If many people have functional seizures alongside biological seizures maybe there is a type of seizure that does not show on an EEG. They should show why that is not a valid pathway.