Crises psychogènes non épileptiques (typologie à partir de l'analyse de 145 crises)

L'auteur se propose d'étudier un groupe particulier de manifestations critiques, réunies sous le vocable de "crises psychogènes non épileptiques" (CPNEL qui constitue une pathologie invalidante et un problème de santé publique. Dans la première partie de ce travail, une revue de la littérature permet de présenter les connaissances actuelles sur ce sujet. Dans un second temps, après avoir étudié les caractéristiques paracliniques et sociodémographiques de la population lorraine touchée par les CPNE, nous nous sommes intéressés à l'aspect sémiologique de ces manifestations. Nous disposons d'une cohorte de 52 patients chez qui a été porté le diagnostic de CPNE, selon la méthode constituant le goldstandard actuel (vidéo-EEG). L'étude de 145 crises a permis d'établir une typologie de 5 classes sémiologiquement distinctes. Au sein de chaque catégorie, il apparaît une certaine homogénéité des manifestations cliniques, attestant d'une reproductibilité inter et intra-patients. A la lumière de ces constatations, nous proposons une approche nouvelle des CPNE, tant sur le plan diagnostique que physiopathologique.NANCY1-SCD Medecine (545472101) / SudocSudocFranceF

Chorea as the presenting manifestation of primary Sjögren's syndrome in a child

International audienceA 12-year-old boy presented with subacute chorea (Figure). He had no personal or familial medical history. Chorea occurred without any history of fever or infection, and rapidly worsened over 3 weeks. Examination was otherwise normal. Cranial magnetic resonance imaging and cerebrospinal fluid examination were normal. Diagnosis of chorea associated with primary Sjögren syndrome was made according to American-European Consensus Group criteria,1 because of the association of xerophthalmia (Schirmer test <5 mm in 5 minutes), positive antinuclear antibodies (1:320) with anti–Sjögren syndrome A specificity, and focal lymphocytic infiltration on salivary gland histology (two infiltrates containing at least 50 lymphocytes in a 4-mm2 glandular section, focus score = 2). Screening for other causes of chorea was negative, specifically including anticardiolipin and antistreptococcal antibodies. There were no other clinical manifestations of Sjögren syndrome. The patient was treated symptomatically with tetrabenazine and valproic acid. Chorea gradually improved within 6 months, until he became asymptomatic and without any treatment

Impaired saccadic adaptation in DYT11 dystonia

International audienceBackground: Recent neuroimaging studies point to a possible pathophysiological role of cerebellar dysfunction in dystonia. The authors investigated the association between sensorimotor adaptation, cerebellar dysfunction and the myoclonus-dystonia phenotype.Methods: The authors prospectively analysed reactive saccade adaptation in a genetically homogeneous group of 14 patients with DYT11 dystonia owing to a mutation of the SGCE gene. The authors used a backward reactive saccade adaptation task, a well-characterised experimental oculomotor paradigm involving the cerebellum. The principle of this paradigm is to simulate a spatial error in saccade generation by systematically shifting a visual target during saccade execution. Repetition of this systematic error induces a gradual decrease in the initial saccade amplitude, reflecting an adaptive phenomenon.Results: Saccade adaptation was significantly lower in the DYT11 patients than in healthy controls (mean value: 8.9%±4.5% vs 21.6%±4.5%; p=8.3×10(-6)). The time course of adaptation also differed between the patients and controls (p=0.002), reflecting the slower saccadic adaptation in the patients.Conclusions: This study provides the first neurophysiological evidence of cerebellar dysfunction in DYT11 dystonia and supports a role of cerebellar dysfunction in the myoclonus-dystonia phenotype

Somatotopy of cervical dystonia in motor-cerebellar networks: Evidence from resting state fMRI.

INTRODUCTION Cervical dystonia is the most frequent form of isolated focal dystonia. It is often associated with a dysfunction in brain networks, mostly affecting the basal ganglia, the cerebellum, and the somatosensory cortex. However, it is unclear if such a dysfunction is somato-specific to the brain areas containing the representation of the affected body part, and may thereby account for the focal expression of cervical dystonia. In this study, we investigated resting state functional connectivity in the areas within the motor cortex and the cerebellum containing affected and non-affected body representations in cervical dystonia patients. METHODS Eighteen patients affected by cervical dystonia and 21 healthy controls had resting state fMRI. The functional connectivity between the motor cortex and the cerebellum, as well as their corresponding measures of gray matter volume and cortical thickness, were compared between groups. We performed seed-based analyses, selecting the different body representation areas in the precentral gyrus as seed regions, and all cerebellar areas as target regions. RESULTS Compared to controls, patients exhibited increased functional connectivity between the bilateral trunk representation area of the motor cortex and the cerebellar vermis 6 and 7b, respectively. These functional abnormalities did not correlate with structural changes or symptom severity. CONCLUSIONS Our findings indicate that the abnormal function of the motor network is somato-specific to the areas encompassing the neck representation. Functional abnormalities in discrete relevant areas of the motor network could thus contribute to the focal expression of CD

Étiopathogénie des troubles neurologiques fonctionnels : marqueurs biologiques et modèles théoriques

National audienceOBJECTIVES: 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. METHODS: We carried out a narrative review of international publications dealing with neuroimaging and biology of functional neurological disorders, from 1997 to 2023. RESULTS: 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. CONCLUSIONS: 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

Impact of Transcranial Magnetic Stimulation on Functional Movement Disorders: Cortical Modulation or a Behavioral Effect?

IntroductionRecent studies suggest that repeated transcranial magnetic stimulation (TMS) improves functional movement disorders (FMDs), but the underlying mechanisms are unclear. The objective was to determine whether the beneficial action of TMS in patients with FMDs is due to cortical neuromodulation or rather to a cognitive-behavioral effect.MethodConsecutive patients with FMDs underwent repeated low-frequency (0.25 Hz) magnetic stimulation over the cortex contralateral to the symptoms or over the spinal roots [root magnetic stimulation (RMS)] homolateral to the symptoms. The patients were randomized into two groups: group 1 received RMS on day 1 and TMS on day 2, while group 2 received the same treatments in reverse order. We blindly assessed the severity of movement disorders before and after each stimulation session.ResultsWe studied 33 patients with FMDs (dystonia, tremor, myoclonus, Parkinsonism, or stereotypies). The median symptom duration was 2.9 years. The magnetic stimulation sessions led to a significant improvement (&gt;50%) in 22 patients (66%). We found no difference between TMS and RMS.ConclusionWe suggest that the therapeutic benefit of TMS in patients with FMDs is due more to a cognitive-behavioral effect than to cortical neuromodulation