Abnormal cerebrospinal fluid cytology in functional movement disorders, 2024, Serranová et al

[dave30th]

Of course, there is some unknown pathology so the label is only useful in acting as a waiting zone.

But for the FND experts, it isn't a waiting zone--FND itself or "software problem"--whatever that means--is the explanation. No need for further investigation. I think Jo's point might be more more that some very small percentage of people--far less than currently given an FND label that now includes, per the experts, all sorts of functional cognitive symptoms as well, and constitutes a third of neurology patients--really do have symptoms that would fit an FND label. In other words, that there really is no pathology. But that in most other cases, FND is a stand-in used by lazy or inept clinicians who slap it on patients without proper investigation. That might not be a fully accurate account of what Jo meant, but he can clarify if need be.

 

[Kitty]

From @MSEsperanza:

These patients had 'mostly sleep disorders'. Goodness knows whether anyone outside the Czech Republic would diagnose them as FND.

Probably not relevant for the main points of the discussion but the abstract only says the controls had mostly sleep disorders while the FND group had functional movement disorders (demarcated from "various neuropsychiatric disorders including the seizure subtype of functional neurological disorder").

Not sure from the abstract if the controls were classified as also having FND--maybe some particular sleep disorders are seen as neurological diagnoses of their own, so won't be under the FND label?

Have no access to the paper, but in the authors' affiliations I can't see any particular link to mainly dealing with people with sleep disorders,so not clear fromwhere they got these patients' data.

Maybe more relevant is the fact that the paper has the label "Brief Communication" and seems to me not an actual study, i.e. they didn't recruit patients and controls for their analysis but just looked at data stored at their own [?] clinic(s). So I think in all patients, including the controls, they had done a lumbar puncture for diagnostic reasons at some time, not for doing a study--with all the implications that has for the validity of the results (e.g. comparability)?

I have no idea but I think it's legitimate to do this kind of retrospective data analysis to look for hints, but not draw any conclusions other than it could be worthwhile to do a proper study on this? If there are considerable overlapping results in such tiny sample sizes, and not clear if the only non-overlapping results are in cells that also could have no pathological relevance at all, maybe first compare larger samples?

 

[Jonathan Edwards]

Probably not relevant for the main points of the discussion but the abstract only says the controls had mostly sleep disorders while the FND group had functional movement disorders

Ah, OK I misread that.
So these people probably had more typical FND movement disorders.

 

[Jonathan Edwards]

But for the FND experts, it isn't a waiting zone--FND itself or "software problem"--whatever that means--is the explanation.

Except that that really only applies to Mark Edwards and co-authors on a handful of speculative papers. For other experts it is bad thoughts from childhood and for the great majority of doctors it is something they do not attempt to resolve. They become familiar with a group of patients with discordant patterns of signs and understand each other when they refer to them to that extent.

 

[Jonathan Edwards]

In other words, that there really is no pathology.

There is always unfound pathology. It is just a question of not being able to find anything that fits with our understanding - unless you concoct self-contradictory speculations like Mark Edwards and co.