Research LettersDiscrete neurophysiological correlates in prefrontal cortex during hysterical and feigned disorder of movement
Summary
The clinical distinction between hysterical symptoms and those that are feigned awaits objective validation. We used functional neuroimaging to examine the neural correlates of these two disorders.
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(1999)
Cited by (231)
Understanding functional neurological disorders: From biological markers to pathophysiological models
2023, EncephaleLongtemps considérés comme des pathologies sans substrat, les troubles neurologiques fonctionnels ont fait l’objet depuis plus de 20 ans d’une activité de recherche importante dans les champs de la neuroimagerie structurelle et fonctionnelle, et plus récemment dans celui des biomarqueurs moléculaires. Ainsi, nous proposons une synthèse des connaissances dans les domaines de la neuroimagerie et de la biologie des troubles neurologiques fonctionnels. Nous proposons également une synthèse des hypothèses phénoménologiques qui leur sont associées. Ces travaux doivent permettre au clinicien de mieux appréhender la nature des mécanismes impliqués, et au patient de mieux comprendre la nature des symptômes dont il souffre.
Nous avons réalisé une revue narrative des articles qui rapportent les principaux résultats de neuroimagerie et de biologie en lien avec la physiopathologie des troubles neurologiques fonctionnels, de 1997 à 2023.
Les symptômes neurologiques fonctionnels sont associés à de multiples anomalies cérébrales fonctionnelles et structurelles au sein de plusieurs régions organisées en réseaux impliqués dans la gestion des ressources cognitives, le contrôle attentionnel, la régulation émotionnelle, l’agentivité et l’intéroception. Les processus effecteurs de la réaction de stress sont également impliqués dans l’expression du phénotype. Le modèle biopsychosocial est opérant pour la description des facteurs prédisposant, précipitant et perpétuant ces mécanismes dans le temps.
Une meilleure connaissance de la spécificité et des déterminants évolutifs des mécanismes présentés est une priorité de la recherche. Leur compréhension est utile pour la mise au point de traitements, mais constitue aussi pour les patients une étape importante dans leur démarche de rétablissement.
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.
Hypnosis in the Treatment of Pediatric Functional Neurological Disorder: The Magic Glove Technique
2021, Pediatric NeurologyThe treatment of functional neurological disorder (FND), previously referred to as conversion disorder, can be challenging. Despite these challenges and with increased understanding of this condition, new treatment options are emerging. One such treatment is hypnosis, which has a long history of use in the treatment of FND. Jean-Martin Charcot, considered by many to be the father of modern neurology, used therapeutic hypnosis as early as the 19th century. In this report, we discuss the novel use of a hypno-anesthetic technique (the magic glove) for treatment of FND presenting as diplegia. We illustrate the use of the technique with the case of a 9-year-old girl who suffered from chronic pain and lower extremity weakness secondary to FND. With the magic glove technique, she improved rapidly and was free of symptoms by her sixth month follow-up visit. We review the current literature on FND interventions and emphasize the need for continued research in this field.
Examination of ECG characteristics of patients admitted to emergency department with conversive attack
2021, American Journal of Emergency MedicineConversion disorder is defined as a disorder with one or more neurological symptoms that accompany psychological conflict, suggesting a physical disorder. It has been shown that patients with conversion disorder have an imbalance in the autonomic nervous system. There are only a limited number of studies that have examined how conversion disorder is related with surface ECG parameters. The present study aimed to investigate the effects of conversion disorder on the surface ECG parameters of patients with conversion disorder admitted to the emergency department.
This cross-sectional case-control study included 98 patients who were admitted to the emergency department and diagnosed with conversion disorder and 56 healthy volunteers. All patients underwent 12-derivation ECG. PR interval, P wave dispersion, duration of QRS complex, QT interval, QTc interval, frontal QRS-T angle values were calculated for all individuals.
When compared with the control group, the conversion disorder group revealed a significant difference in terms of PWD [60 (40–80) vs. 40 (40–60) P = 0.01], QT [385 (364–410) vs. 378 (354–394), P = 0.048], QTc [420 (405–430) vs. 406 (397–429), P = 0.039], and frontal QRS-T angle [25 (15–33) vs. 20 (8–35), P = 0.018]. In the multivariate linear regression analysis, conversion disorder was found to be an independent predictor for both PWD (β = 0.196, P = 0.014) and frontal QRS-T angle (β = 0.258, P = 0.011).
This study is the first to show that conversion disorder significantly increases QT, QTc, P wave dispersion, and frontal QRS-T angle.
A dimensional approach to functional movement disorders: Heresy or opportunity
2021, Neuroscience and Biobehavioral ReviewsFunctional movement disorders (FMD) are a common and disabling neuropsychiatric condition, part of the spectrum of functional neurological/conversion disorder. FMD represent one of the most enigmatic disorders in the history of medicine. However, in the twenty years after the first report of distinctive abnormal brain activity associated with functional motor symptoms, there have been tremendous advances in the pathophysiologic understanding of these disorders. FMD can be characterized as a disorder of aberrant neurocircuitry interacting with environmental and genetic factors.
These developments suggest that research on FMD could be better served by an integrative, neuroscience-based approach focused on functional domains and their neurobiological substrates. This approach has been developed in ‘Research Domain Criteria’ (RDoC) project, which promotes a dimensional approach to psychiatric disorders. Here, we use the RDoC conceptualization to review recent neuroscience research on FMD, focusing on the domains most relevant to these disorders. We discuss how the adoption of a similar integrative framework may facilitate the identification of the mechanisms underlying FMD and could also have potential clinical applicability.
Neuroimaging in Functional Neurological Disorder: State of the Field and Research Agenda
2021, NeuroImage: ClinicalFunctional neurological disorder (FND) was of great interest to early clinical neuroscience leaders. During the 20th century, neurology and psychiatry grew apart – leaving FND a borderland condition. Fortunately, a renaissance has occurred in the last two decades, fostered by increased recognition that FND is prevalent and diagnosed using “rule-in” examination signs. The parallel use of scientific tools to bridge brain structure - function relationships has helped refine an integrated biopsychosocial framework through which to conceptualize FND. In particular, a growing number of quality neuroimaging studies using a variety of methodologies have shed light on the emerging pathophysiology of FND. This renewed scientific interest has occurred in parallel with enhanced interdisciplinary collaborations, as illustrated by new care models combining psychological and physical therapies and the creation of a new multidisciplinary FND society supporting knowledge dissemination in the field. Within this context, this article summarizes the output of the first International FND Neuroimaging Workgroup meeting, held virtually, on June 17th, 2020 to appraise the state of neuroimaging research in the field and to catalyze large-scale collaborations. We first briefly summarize neural circuit models of FND, and then detail the research approaches used to date in FND within core content areas: cohort characterization; control group considerations; task-based functional neuroimaging; resting-state networks; structural neuroimaging; biomarkers of symptom severity and risk of illness; and predictors of treatment response and prognosis. Lastly, we outline a neuroimaging-focused research agenda to elucidate the pathophysiology of FND and aid the development of novel biologically and psychologically-informed treatments.
The pathophysiology of functional movement disorders
2021, Neuroscience and Biobehavioral ReviewsFunctional neurological disorder is characterized by neurological symptoms that cannot be explained by typical neurological diseases or other medical conditions. This review will critically discuss the literature on the pathophysiology of functional movement disorders (FMD), including functional neuroimaging studies, neurophysiological studies, studies on biomarkers and genetic studies. According to PRISMA guidelines for systematic reviews, we selected 39 studies. A complex scenario emerged, with the involvement of different areas of the brain in the pathophysiology of FMD. Our findings showed a hypoactivation of the contralateral primary motor cortex, a decreased activity in the parietal lobe, an aberrant activation of the amygdala, an increased temporo-parietal junction activity and a hyperactivation of insular regions in patients with FMD. Functional connectivity (FC) findings underlined aberrant connections between amygdala and motor areas, temporo-parietal junction and insula. We proposed amygdala hyperactivation as a possible biological marker for FMD and FC alterations between amygdala and other areas of the brain as consequent epiphenomena, accounting for the pathophysiological complexity of FMD. These conclusions might drive novel treatment hypotheses.