Earlier quoted context omitted.
This guy is probably chasing moonshine, but TBH "functional neurological disorder" sounds like one of those face-saving labels that doctors use when they don't have any idea what's going on.
It is not meant to save the doctors face. The very definition of FND is "doctors dont know what is wrong, but they acknowledge that your symptoms are real". The point of giving it a name is in the second part. Its about explicitly acknowledging the limitations of medicine
For a competent doctor it's used too let a patient know they're doing their job and an acknowledgement of symptoms.
Unfortunately to a _lot_ of the field "catch-all" "diagnoses" (in intentionally separating these labels). It's the same as diagnosing someone with chronic fatigue. It's diagnosing via exclusion.
The difference between chronic fatigue and brain disorders being that you're more likely to get someone looking to make a "name for themselves" diagnosing or curing the latter vs the former...