Functional neurological symptoms occur commonly in healthy adults: implications for the pathophysiology of FND 2026 Palmer et al

Andy

Senior Member (Voting rights)
Abstract

Objectives:
Functional neurological symptoms which do not meet clinical definitions of functional neurological disorder (FND) are common in clinical practice. Understanding the distinction between these ‘benign’ functional symptoms and FND is crucial in defining FND as an entity for study, and as a clinical syndrome. We aimed to measure the frequency of functional symptoms in people who do not have FND.

Methods:
A survey was administered to 95 clinicians who attended an international conference on FND. Participants were asked to report the occurrence and characteristics of experiences with features of functional sensory or motor symptoms, or dissociation, which they had experienced at any time.

Results:
Of the 95 people who responded to the survey, 57.4% reported having experienced any functional symptoms, and 47.9% reported having experienced functional motor or sensory symptoms. The symptoms reported were generally short-lived and caused only mild distress and disruption. Most respondents who reported having experienced a functional symptom reported having had multiple events through their lives.

Interpretation:
The results suggest that the lifetime occurrence of functional neurological symptoms is at least two orders of magnitude higher than the prevalence of FND. The high prevalence of functional symptoms in people who have never had FND challenges the common assumption that the occurrence of functional neurological symptoms is synonymous with FND. We propose that FND is better conceived of as a failure of the mechanisms by which functional neurological symptoms resolve, rather than the occurrence of functional symptoms per se. This reconceptualization implies new research directions for the underlying aetiology of FND.

Open access
 
And what are "functional symptoms", you might not care to ask but have to for miserable reasons?
Functional symptoms are neurological symptoms which are generated by abnormal brain processing.6 They are distinctive in their striking and paradoxical variation in
intensity with symptom-focused attention or effort to overcome the symptom. Typically, greater levels of symptom-focused attention are associated with increases in
symptom-severity, and direction of selective attention elsewhere causes reduction or complete remission of the symptom.7,8 Functional symptoms encompassing almost all categories of neurological symptoms are seen, including abnormalities of movement, sensation (both somatosensation and the special senses), consciousness, and cognition.9
Anything you want. By this definition, hunger would count as a "functional" symptom, as would sleepiness, nausea and anything you can think of that involves senses in some way. Noticeable that this definition is entirely circular, because how is this "abnormal brain processing" defined? By having "functional" symptoms, of course!

The mysticism, it spreads, it just keeps spreading, to parts known and unknown.
 
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