Introduction Les ataxies cérébelleuses sporadiques de début tardif (SLOCA) regroupent diverses étiologies dont l’atrophie multisystématisée cérébelleuse (AMS-C). La sensibilité des critères diagnostic reste néanmoins limitée aux stades précoces de la maladie. Objectifs Notre objectif est de développer une prédiction dynamique et multimodale de la phénoconversion de SLOCA en AMS-C grâce aux modèles joints. Méthodes 417 patients référés pour SLOCA au CHU de Strasbourg entre janvier 2012 et décembre 2024 ont été sélectionnés, dont 65 atteints d’AMS-C et 277 contrôles retenus dans l’analyse. L’UPDRS-III, le SARA, les paramètres de tests d’hypotension orthostatique (HTO), l’aire du pont et la valeur d’ADC des pédoncules cérébelleux moyens (PCM) ont été analysés à l’aide de modèles mixtes. Un modèle de prédiction dynamique a ensuite été développé à l’aide de forêts d’arbres décisionnels. Résultats L’AMS-C se caractérise par une dégradation plus rapide des scores SARA et UPDRS-III, une décroissance sigmoïde de l’aire pontique et une élévation continue de l’ADC des PCM. Notre modèle de prédiction dynamique reposant sur ces derniers paramètres ainsi que le ratio de captation putamen/occipital et la pression artérielle systolique du test d’HTO démontre de solides performances quantifiées par un score Brier intégré de 0,023 et surpasse les critères 2008 et 2022 lors d’une comparaison directe (Fig. 1). Discussion Notre modèle de prédiction dynamique permet l’identification précoce de l’AMS-C parmi les SLOCA et surpasse les critères diagnostiques actuels tout en se basant sur un nombre limité de prédicteurs cliniques et d’imagerie. Nous émettons l’hypothèse que nos travaux permettront de guider l’inclusion des patients dans les futurs essais de neuroprotection. Conclusion Nous avons démontré que l’intégration longitudinale de données cliniques, radiologiques et scintigraphiques permettait d’estimer de manière individualisée et précise la probabilité de phénoconversion vers l’AMS-C à partir de SLOCA.

Introduction Le jeu de tête expose les footballeurs à des impacts crâniens sous-commotionnels répétés. Plusieurs études épidémiologiques ont rapporté une augmentation du risque de troubles neurodégénératifs chez les anciens joueurs professionnels1,2, suggérant un rôle potentiel des impacts crâniens répétés dans la survenue d’altérations cérébrales chroniques. Parmi les biomarqueurs structurels décrits dans les sports de contact, l’élargissement du cavum septi pellucidi (CSP)3 et les hypersignaux de la substance blanche4 sont régulièrement associés à l’exposition cumulative aux traumatismes. Cependant, les données IRM in vivo spécifiques aux footballeurs restent limitées. Objectif Identifier des marqueurs structurels IRM associés aux impacts crâniens répétés chez des footballeurs professionnels en fin de carrière ou récemment retraités, sans antécédent de commotion, comparés à des athlètes de haut niveau issus de sports sans risque de contact. Matériel et méthodes Cohorte prospective monocentrique incluant 29 footballeurs et 27 témoins. Tous ont bénéficié d’une IRM 3T comprenant : segmentation manuelle du CSP sur T1 3D, quantification automatisée des hypersignaux de la substance blanche en FLAIR et recherche de micro-hémorragies sur SWI. Une évaluation neuropsychologique standardisée a été réalisée. Résultats Les footballeurs présentent un volume de CSP significativement plus élevé (25,1 vs 5,2 mm³ ; p < 0,001), indépendamment de l’âge et de la morphologie septale. Le volume total d’hypersignaux FLAIR est augmenté (4006 vs 2921 mm³ ; p = 0,03) indépendamment de l’âge, avec une prédominance périventriculaire, malgré des scores de Fazekas normaux. Aucun micro-saignement n’est détecté. Aucune altération cognitive n’est observée. Conclusion L’étude met en évidence des marqueurs IRM quantitatifs – élargissement du CSP et augmentation des hypersignaux FLAIR périventriculaires – suggérant l’existence d’altérations cérébrales subcliniques liées au jeu de tête répété. L’évaluation de leur pertinence clinique nécessite des explorations longitudinales.

PURPOSE:Neuroradiological findings associated with neurological presentations in acute SARS-CoV-2 infection are very heterogeneous. We aimed to develop a standardized framework for describing MR neuroimaging patterns in Covid-19, to test this in an international multicentre study and to determine the prevalence of observed MRI patterns and their association with clinical presentation and outcome. METHODS:An international expert consortium developed a framework for assessment of brain MRI patterns in Covid-19 based on published literature and professional experience. We performed a retrospective analysis of the proposed framework, involving brain MRI scans from 458 Covid-19 patients with neurological symptoms, including data from 1 February to 31 May 2020. Two readers at 25 centres across five countries assessed the local MRI studies regarding the presence of one or more predefined MRI patterns. Imaging and clinical data were analysed using Bayesian statistics. RESULTS:Of 458 patients, 58.5% had an abnormal MRI. Overall, 94% of all imaging pathologies seen were captured by our proposed classification. Ischemic strokes were the most frequent pattern overall (25.6%), followed by microhaemorrhages (15.9%). Ischemic infarct patterns were more frequent in non-ICU patients, while the haemorrhagic patterns were more frequent in ICU patients. White matter lesions (10.9%) were more frequent than grey matter lesions (8.1%), and leptomeningeal contrast enhancement was present in 8.3% of patients. Patient outcome was not associated with any MRI patterns. CONCLUSION:Our proposed classification of specific MRI patterns in Covid-19, covered 94% of observed abnormalities, while patient outcome, death or home discharge, was not associated with any MRI patterns.

Background Currently, there are no available recommendations or guidelines on how to perform MRI monitoring in the management of neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD). The issue is to determine a valuable MRI monitoring protocol to be applied in the management of NMOSD and MOGAD, as previously proposed for the monitoring of multiple sclerosis. Objectives The objectives of this work are to establish proposals for a standardized and feasible MRI acquisition protocol, and to propose control time points for systematic MRI monitoring in the management of NMOSD and MOGAD. Methods A steering committee composed of 7 neurologists and 5 neuroradiologists, experts in NMOSD and MOGAD from the French group NOMADMUS, defined 8 proposals based on their expertise and a review from the literature. These proposals were then submitted to a Rating Group composed of French NMOSD / MOGAD experts. Results In the management of NMOSD and MOGAD, a consensus has been reached to perform systematic MRI of the brain, optic nerve and spinal cord, including cauda equina nerve roots, at the time of diagnosis, both without and after gadolinium administration. Moreover, it has been agreed to perform a systematic MRI scan 6 months after diagnosis, focusing on the area of interest, both without and after gadolinium administration. For long-term follow-up of NMOSD and MOGAD, and in the absence of clinical activity, it has been agreed to perform gadolinium-free MRI of the brain (+/- optic nerves) and spinal cord, every 36 months. Ideally, these MRI scans should be performed on the same MRI system, preferably a 3T MRI system for brain and optic nerve MRI, and at least a 1.5T MRI system for spinal cord MRI. Conclusions This expert consensus approach provides physicians with proposals for the MRI management of NMOSD and MOGAD.

Background: Contrast-enhanced magnetic resonance imaging (MRI) is the imaging modality routinely used to follow up patients who have undergone surgical resection of brain meningiomas. There are growing concerns about the massive use of gadolinium-based contrast agents (GBCA). Our aim was to evaluate the performance of a new imaging protocol, performed without GBCA injection, in the detection of tumoral residue or local recurrence after surgery of parafalcine and convexity meningiomas. Materials and methods: Only adult patients with a documented resected parafalcine or convexity meningioma were included. We performed a dedicated MRI protocol that included non-contrast and post-contrast sequences. The presence or absence of residue on the unenhanced sequences was independently recorded by three observers: first blindly, then in comparison with a baseline enhanced MRI examination. Results: A total of 51 patients were included. 37 of them featured a tumor residue on the reference enhanced sequence. Overall, an average of 32 of 37 (87%) residues were identified on the unenhanced sequences that were blindly reviewed; and more than 34 of 37 (93%) were identified with the help of the comparative baseline enhanced examination, with a high sensitivity. The missed cases were related to small residues. Conclusion: Unenhanced MRI sequences are highly sensitive and specific in identifying a tumor residue or a local recurrence in the post operative follow up of brain meningiomas. Sensitivity is even higher with the help of a comparative baseline enhanced MRI examination, whatever the strength of magnetic field. (c) 2023 Elsevier Masson SAS. All rights reserved.

INTRODUCTION:Practical MRI training is essential for bridging the gap between complex theoretical knowledge and clinical applications. Traditional phantoms used in MRI, such as ACR phantoms, are valuable for illustrating system characterization methods but often lack the anatomical complexity required for realistic training. This study presents the development of high-fidelity anatomical phantoms designed specifically for practical MRI training. These phantoms replicate key anatomical structures and tissue contrasts of the head, offering a more realistic training experience for healthcare students and medical imaging staff (radiologists, physicists, radiographers). MATERIALS AND METHODS:We focused on the head region, creating phantoms from reference MRI T1-weighted slices and using computer-aided design (CAD) software to design detailed anatomical structures. These phantoms were 3D printed and filled with tissue-mimicking gels. MRI acquisitions were performed using a 1.5T clinical MRI system. RESULTS:The resulting images demonstrated high anatomical fidelity and realistic MRI tissue contrasts. The phantoms allow for effective demonstration of the impact of parameter modifications on MRI images and aid in anatomical structure recognition. CONCLUSION:While technical improvements are needed to ensure long-term stability and accurate relaxometric properties, these phantoms hold significant potential for enhancing MRI education and sequences evaluations. The approach can be extended to other anatomical regions, further supporting the training and optimization of MRI sequences.

Whether spinocerebellar ataxia 27B (SCA27B) may present as a cerebellar multiple system atrophy (MSA-C) mimic remains undetermined. To assess the prevalence of FGF14 (GAA)≥250 expansions in patients with MSA-C, to compare SCA27B and MSA-C clinical presentation and natural history. FGF14 expansion screening combined with longitudinal deep-phenotyping in a prospective cohort of 195 patients with sporadic late-onset cerebellar ataxia. After a mean disease duration of 6.4 years, 111 patients were not meeting criteria for MSA-C while 24 and 60 patients had a final diagnosis of possible and probable MSA-C, respectively. 16 patients carried an FGF14 (GAA)≥250 expansion in the group not meeting MSA-C criteria (14.4

To determine the incidence of acute neuroimaging (NI) findings and comorbidities in the coronavirus disease of 2019 (COVID‐19)‐infected subjects in seven U.S. and four European hospitals.

Rationale and objectives. - Evaluate the implementation of an MRI scanner dedicated to emergencies on the management of patients admitted in the emergency department (ED) for binocular diplopia (BD). Material and methods. - This was a prospective non-interventional single-center study from February 2018 to February 2020. A total of 110 patients were included: 52 patients during the first stage (29 women; 23 men; mean age 65.2 years); 58 during the second stage (29 women; 29 men; mean age 51.4 years). Patients underwent an enhanced-CT examination in the first stage and an MRI examination in the second stage. Criteria used to evaluate the new management of patients were: proportion of patients with an imaging diagnosis explaining BD, turnaround time (TT), ED length of stay (EDLOS), hospital admission rate, hospital length of stay (HLOS), number of MRI examinations requested as a second procedure for the same indication and radiation doses. Descriptive statistics were used to present results with Student's test for quantitative variables and chi-square test for qualitative variables. Results. - Respectively 1 (1.92%) and 17 (29.31%) patients had definitive diagnosis in stages 1 and 2, with a significant difference in examination modalities (p = 0.0001). The TT, EDLOS, hospital admission rate, and HLOS were not significantly different between the two stages. Radiation dose was significantly different between the two groups (p < 0.05). Conclusion. - Implementation of an MRI scanner dedicated to emergencies can improve the etiological diagnostic performance of binocular diplopia and reduce patient's exposure to ionizing radiation without increasing the average turnaround time or emergency department length of stay. & COPY; 2021 Elsevier Masson SAS. All rights reserved.

Heterozygous GAA expansions in the FGF14 gene have been related to autosomal dominant cerebellar ataxia (SCA27B‐MIM:620174). Whether they represent a common cause of sporadic late‐onset cerebellar ataxia (SLOCA) remains to be established.

We report a case of severe tick-borne encephalitis in a pregnant woman, leading to a prolonged stay in the intensive care unit. She showed minor clinical improvement >6 months after her presumed infection. The patient was not vaccinated, although an effective vaccine is available and not contraindicated during pregnancy.

L'encéphalite de Rasmussen est une maladie inflammatoire rare et destructrice. Lorsque la maladie commence à l'âge adulte, ce qui est le cas pour environ 10 % des patients, son évolution radio-clinique est souvent plus favorable. Recherche de biomarqueurs radiologiques des formes tardives. Nous analysons ici les aspects cliniques et radiologiques longitudinaux de façon rétrospective pour cinq patients avec encéphalite de Rasmussen débutant à l'âge adulte (âge moyen de début 39 ans [26–53 ans]) avec leur présentation initiale et leur devenir radiologique via une analyse détaillée lobe par lobe, avec un suivi moyen de 8,2 ans (2 à 16 ans). L'atteinte radiologique était souvent focale ou multifocale, intéressant entre autres le lobe temporal et l'hippocampe (5/5), l'insula, le lobe pariétal, l'hémisphère controlatéral (5/5), ainsi que le noyau caudé (4/5). Les deux patients les plus jeunes (< 30 ans) ainsi que trois patients pédiatriques à début tardif présentaient des aspects « d'encoches » corticales multifocales et insulaires. L'encéphalite de Rasmussen de l'adulte est marquée par une évolution radiologique moins rapide et plus limitée en termes spatiale par rapport aux formes classiques du jeune enfant. Les formes circonscrites des patients jeunes se caractérisent par un aspect radiologique particulier sous forme « d'encoches », très marquées dans la région insulaire et périsylvienne. Nous proposons que l'évolution vers une atrophie focale de type « encoche » soit particulièrement typique de l'encéphalite de Rasmussen à début à partir de la pré-adolescence.

Registration is a crucial step in the design of automatic change detection methods dedicated to longitudinal brain MRI. Even small registration inaccuracies can significantly deteriorate the detection performance by introducing numerous spurious detections. Rigid or affine registration are usually considered to align baseline and follow-up scans, as a pre-processing step before applying a change detection method. In the context of multiple sclerosis, using deformable registration can be required to capture the complex deformations due to brain atrophy. However, non-rigid registration can alter the shape of appearing and evolving lesions while minimizing the dissimilarity between the two images. To overcome this issue, we consider registration and change detection as intertwined problems that should be solved jointly. To this end, we formulate these two separate tasks as a single optimization problem involving a unique energy that models their coupling. We focus on intensity-based change detection and registration, but the approach is versatile and could be extended to other modeling choices. We show experimentally on synthetic and real data that the proposed joint approach overcomes the limitations of the sequential scheme.

OBJECTIVES:The purpose of this study was to compare the costs and organizational benefits of diagnostic workup without and with MRI dedicated to the ED.METHODS:We conducted a prospective observational uncontrolled before-after study in one ED of a university hospital in France from July 1, 2018, and January 3, 2020. We included all consecutive patients presenting with dizziness or diplopia. The main outcomes were the clinical decision time of ED physicians and the total costs for each strategy. Outcomes were compared using propensity score with inverse probability weighting in the 2 arms and an incremental cost-effectiveness ratio (ICER) was calculated.RESULTS:Among the 199 patients during the "before" period (average age: 60.4 years ± 17.6): 112 men (57%), and 181 during the "after" period (average age, 54.8 years ± 18.5): 107 men (59%), the average costs were €2701 (95% CI 1918; 3704) and €2389 (95% CI: €1627; 3280) per patient, respectively. The average time to clinical decision was 9.8 h (95% CI: 8.9 10.7) in the group "before" and 7.7 h (95% CI: 7.1; 8.4) in the group "after" (ICER: €151 saved for a reduction of 1 h in clinical decision time). The probabilistic sensitivity analysis estimated a 71% chance that the MRI dedicated to ED was dominant (less costly and more effective).CONCLUSION:Easy access to MRI in the ED for posterior circulation stroke-like symptoms must be considered a relevant approach to help physicians for an appropriate and rapid diagnostic with reduction of costs.TRIAL REGISTRATION:NCT03660852 KEY POINTS: • A dedicated MRI in the ED for diplopia or dizziness may be considered an efficient strategy improving diagnostic performance, reducing physicians' decision time, and decreasing hospital costs. • This strategy supports clinical decision-making with early treatment and management of patients with posterior circulation-like symptoms in the ED. • There is 71% chance that the MRI dedicated to ED was dominant (less costly and more effective) compared with a strategy without dedicated MRI.

A significant but reversible inhibition of phenazone elimination was observed in rabbits chronically exposed to CS2. Lack of significant difference of phenazone pharmacokinetics in exposed rabbits 24 h after the last exposure compared with the control group, indicates that alteration of phenazone elimination after chronic exposure to CS2 is reversible. The results obtained with phenazone as a model substance suggest that, during chronic exposure to CS2, elimination of other drugs metabolized by the pathway similar to phenazone may also be altered. This should be taken into account in selecting their dosage.