[Understanding functional neurological disorders: From biological markers to pathophysiological models]

Author: Ismael Conejero1, Eric Thouvenot2, Coraline Hingray3, Cécile Hubsch4, Wissam El-Hage5, Guilhem Carle-Toulemonde6, Jean-Yves Rotge7, Sophie Drapier8, Dominique Drapier9, Stéphane Mouchabac10
1 Département de psychiatrie, CHU de Nîmes, PSNREC, Inserm, université de Montpellier, Nîmes, France. Electronic address: ismael.conejero@gmail.com.
2 Département de Neurologie, CHU Nîmes, université de Montpellier, institut de génomique fonctionnelle, University Montpellier, CNRS, Inserm, Montpellier, France.
3 Pôle hospitalo-universitaire de psychiatrie d'adultes du Grand Nancy, centre psychothérapique de Nancy, Laxou, France.
4 Département de neurologie, unité Parkinson, hôpital Fondation Adolphe-de-Rothschild, Paris, France.
5 Clinique psychiatrique universitaire, CHRU de Tours, Tours, France.
6 Cabinet de psychosomatique et stimulation magnétique transcrânienne, clinique Saint-Exupéry, 31400 Toulouse, France.
7 Service de psychiatrie d'adultes, Pitié-Salpêtrière Hospital, AP-HP, Sorbonne université, 47-83, boulevard de l'Hôpital, 75651 Paris, France.
8 Département de neurologie, CHU de Rennes, CIC Inserm 1414, Rennes, France.
9 Département de psychiatrie adulte, CH Guillaume-Régnier, université de Rennes, Rennes, France.
10 Département de psychiatrie, CHU Saint-Antoine, AP-HP, iCRIN Psychiatry (Infrastructure of Clinical Research in Neurosciences-Psychiatry), Institut du cerveau et de la moelle (ICM), Université Sorbonne, Inserm, CNRS, Paris, France.
Conference/Journal: Encephale
Date published: 2023 Jul 1
Other: Special Notes: doi: 10.1016/j.encep.2023.06.003. , Word Count: 260

Functional neurological disorders have witnessed intense research activity in the fields of structural and functional neuroimaging for more than twenty years. Thus, we propose a synthesis of recent research findings and etiological hypotheses that have been proposed so far. This work should help clinicians to better understand the nature of the mechanisms involved, but also help patients to increase their knowledge about the biological features underlying their functional symptoms.

We carried out a narrative review of international publications dealing with neuroimaging and biology of functional neurological disorders, from 1997 to 2023.

Several brain networks underlie functional neurological symptoms. These networks play a role in the management of cognitive resources, in attentional control, emotion regulation, in agency and in the processing of interoceptive signals. The mechanisms of the stress response are also associated with the symptoms. The biopsychosocial model helps to better understand predisposing, precipitating, and perpetuating factors involved. The functional neurological phenotype results from the interaction between: i) a specific pre-existing vulnerability resulting from biological background and epigenetic modifications, and ii) exposure to stress factors, according to the stress-diathesis model. This interaction causes emotional disturbances including hypervigilance, lack of integration of sensations and affects, and emotional dysregulation. These characteristics in turn impact the cognitive, motor and affective control processes related with the functional neurological symptoms.

A better knowledge of the biopsychosocial determinants of brain network dysfunctions is necessary. Understanding them would help developing targeted treatments, but is also critical for patients care.

Keywords: Functional neurological disorders; Neuroimagerie; Neuroimaging; Neuroscience; Neurosciences; Stress; Trouble neurologique fonctionnel.

PMID: 37394415 DOI: 10.1016/j.encep.2023.06.003