Academic Journal
The case against the 'S': Is functional neurological disorder(s) one condition or many?
| Τίτλος: | The case against the 'S': Is functional neurological disorder(s) one condition or many? |
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| Συγγραφείς: | Palmer DDG; The Queensland Brain Institute, The University of Queensland, St Lucia QLD, Australia; Department of Neurology, Sunshine Coast Hospital and Health Service, Birtinya QLD, Australia; Department of Rehabilitation, Sunshine Coast Hospital and Health Service, Birtinya QLD, Australia. Electronic address: david.palmer@uq.edu.au., Edwards MJ; Institute of Psychiatry, Psychology & Neuroscience, King's College London, United Kingdom., Mattingley JB; The Queensland Brain Institute, The University of Queensland, St Lucia QLD, Australia; School of Psychology, The University of Queensland, St Lucia QLD, Australia. |
| Πηγή: | Cortex; a journal devoted to the study of the nervous system and behavior [Cortex] 2026 Aug 13; Vol. 204, pp. 133-143. Date of Electronic Publication: 2026 Aug 13. |
| Publication Model: | Ahead of Print |
| Τύπος έκδοσης: | Journal Article |
| Γλώσσα: | English |
| Στοιχεία περιοδικού: | Publisher: Masson Country of Publication: Italy NLM ID: 0100725 Publication Model: Print-Electronic Cited Medium: Internet ISSN: 1973-8102 (Electronic) Linking ISSN: 00109452 NLM ISO Abbreviation: Cortex Subsets: MEDLINE |
| Imprint Name(s): | Publication: Milan : Masson Original Publication: Varese. |
| Περίληψη: | Functional neurological disorder (FND) is one of the most common, but least researched, conditions in neurology. It can cause a broad range of sensory, motor, and constitutional symptoms, with the underlying mechanism of symptom-generation proposed to be an abnormality of perceptual inference. Debate exists as to whether the clinical entity referred to as FND is truly a single disorder or is in fact multiple entities which have been erroneously amalgamated into the same condition. We sought to provide empirical evidence on this question by treating it as a problem of model comparison. We formulated statistical models equivalent to: (1) FND being a single entity with variation in phenotype, represented by latent trait models, and (2) FND being multiple discrete entities, represented by latent class models. We fitted these models to data on the symptoms experienced by 697 people with FND from the FND Research Connect database (www.fnd-research.org) and used Bayesian model comparison to compare their likelihoods. All but one of the latent trait models, representing FND as a single entity with heterogeneous phenotype, fit the data better than all the latent class models. Furthermore, secondary analysis of the latent class models showed results compatible with the models discretising continuous variation rather than capturing true discrete categories. Our results are most compatible with the hypothesis that the symptom structure of FND is the result of a single pathophysiological process, either as a single entity, or a common pathway preceded by multiple causative processes where the common pathway is solely responsible for the phenotype. (Copyright © 2026 The Authors. Published by Elsevier Ltd.. All rights reserved.) |
| Competing Interests: | Declaration of competing interest D.D.G.P is the unpaid project lead of FND Research Connect. M.J.E. does medical expert reporting in personal injury and clinical negligence cases. M.J.E. has shares in Brain & Mind, which provides neuropsychiatric and neurological rehabilitation in the independent medical sector. M.J.E. has received financial support for lectures from the International Parkinson's and Movement Disorders Society and the FND Society (FNDS). M.J.E. receives royalties from Oxford University Press for his book The Oxford Specialist Handbook of Parkinson's Disease and Other Movement Disorder. M.J.E has received honoraria for medical advice to Teva Pharmaceuticals and educational events. M.J.E. receives grant funding from the National Institute for Health and Care Research (NIHR). M.J.E. is an associate editor of the European Journal of Neurology. M.J.E is a board member of the FNDS. M.J.E. is on the medical advisory boards of the charities FND Hope UK and the British Association of Performing Arts Medicine. |
| Contributed Indexing: | Keywords: Diagnostic structure; Functional Neurological Disorder; Mechanism; Model comparison; Nosology |
| Entry Date(s): | Date Created: 20260824 Latest Revision: 20260824 |
| Update Code: | 20260825 |
| DOI: | 10.1016/j.cortex.2026.08.007 |
| PMID: | 42636743 |
| Βάση Δεδομένων: | MEDLINE |
| ISSN: | 1973-8102 |
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| DOI: | 10.1016/j.cortex.2026.08.007 |