Review Incidence and prevalence of functional neurological disorder: a systematic review, 2024, Finkelstein, Diamond, Carson, Stone

[SNT Gatchaman]

Incidence and prevalence of functional neurological disorder: a systematic review
Sara A Finkelstein; Clare Diamond; Alan Carson; Jon Stone

BACKGROUND
Robust epidemiological data regarding population incidence and prevalence of functional neurological disorder (FND) would be helpful with regards to resource allocation and planning for this disorder, particularly given high symptom burden and high healthcare utilisation. We therefore aimed to systematically review and synthesise available data on FND incidence and prevalence.

METHODS
PubMed was searched to identify original research articles that reported on the incidence or prevalence of FND. Risk of bias assessment for each study was conducted. Incidence and prevalence rates of FND were additionally estimated by extrapolating data from low risk of bias studies on functional seizures alone.

RESULTS
Thirty-nine articles were included. Nineteen reported on FND incidence, 21 reported on prevalence. Comparison between studies was difficult due to methodological differences and significant heterogeneity of incidence and prevalence estimates was found. The incidence of FND was estimated at 10–22/100 00, while minimum prevalence of FND was estimated at 80–140/100 000, with a possible range of 50–1600/100 000. Incidence of paediatric FND was estimated to be between 1 and 18/100 000.

CONCLUSIONS
The range of incidence and prevalence varies widely across studies, with significant heterogeneity among studies and most studies likely provide underestimates due to methodological challenges. However, using our best method as a conservative estimate, there are likely a minimum of 50–100 000 people with FND in the UK, as an example country. Given that FND appears to be more prevalent than many other well-known and well-funded neurological disorders, incidence and prevalence data suggested here indicate the need for greater research and clinical funding allocation to FND programmes.


Link | PDF (Journal of Neurology, Neurosurgery & Psychiatry) [Open Access]

 

[Jonathan Edwards]

So FND is quite uncommon at about one person in 1000, which is fairly credible for movement disorders without a structural explanation.

It tends to suggest that claims of flooding of neurology clinics are inflated.

 

[dave30th]

If they were honest, they would cite the published letter to the journal NeuroImage: Clinical, in which several of us, including Jo, pointed out how they have inflated their statistics for years.

 

[dave30th]

So FND is quite uncommon at about one person in 1000

Just to be clear, they're excluding functional cognitive disorder and PPPD (dizziness) from this group, since they have only recently decided to add those categories to the FND umbrella. Given that cognitive disorders and dizziness from OI etc are common long covid symptoms, it's not surprising these folks look and Long Covid and see FND.

 

[Yann04]

it's not surprising these folks look and Long Covid and see FND.

What’s worrying me is that the long COVID clinics in my area has started auto referring anyone with disabling symptoms to an FND clinic.

 

[dave30th]

What’s worrying me is that the long COVID clinics in my area has started auto referring anyone with disabling symptoms to an FND clinic.

where is this? You mean the LC won’t see patients with symptoms? Who goes there in that case?

 

[Yann04]

where is this? You mean the LC won’t see patients with symptoms? Who goes there in that case?

Lausanne University (CHUV) Long COVID clinic.

They refer anyone with brain fog or “unexplained” disability to the memory clinic which is a run by a neurologist who basically diagnoses anything and everything unexplained as FND.

The long COVID clinic will still see you but only after you go to the referrals they set up for you.

For me for example they stopped seeing me because I tried to go to all the referrals they set up for me and a mix of bad doctors (FND diagnosis) and just generally overdoing it meant I became bedridden and couldn’t make it to appointments anymore. (They don’t offer virtual and are the only long COVID clinic in my state, so that was kind of the end of my interaction with the medical system, been “missing” since then).