Search

International audience; Background: Outcomes of coronavirus disease 2019 (COVID-19) in patients with neuromyelitis optica spectrum disorders (NMOSD) or myelin oligodendrocyte glycoprotein antibody-associated disease (MOGAD), often treated with immunosuppressive therapies, are still unknown.Methods: We conducted a multicenter, retrospective, observational cohort study among all French expert centers for neuromyelitis optica and related disorders. Patients with NMOSD or MOGAD included in the study received a confirmed or highly suspected diagnosis of COVID-19 between 1 March 2020 and 30 June 2020. Main outcome was COVID-19 severity score assessed on a seven-point ordinal scale ranging from 1 (not hospitalized with no limitations on activities) to 7 (death).Results: Fifteen cases (mean [SD] age: 39.3 [14.3] years, 11 female) were included. Five patients (33.3%) were hospitalized, all receiving rituximab. A 24-year-old patient with positive aquaporine-4 antibody, with obesity as comorbidity, needed mechanical ventilation. Outpatients were receiving anti-CD20 (5), mycophenolate mofetil (3) or azathioprine (3). They were younger (mean [SD] age: 37.0 [13.4] years), with a longer disease duration (mean [SD]: 8.3 [6.3] years) and had a lower expanded disability severity score (EDSS) score (median [range] EDSS: 2.5 [0-4]) relative to patients requiring hospitalization (mean [SD] age: 44.0 [16.4] years, mean [SD] disease duration: 5.8 [5.5] years, median [range] EDSS: 4 [0-6.5]).Conclusions: COVID-19 outcome was overall favorable in this cohort. Larger international studies are needed to identify risk factors of severe COVID-19; however, we recommend personal protective measures to reduce risk of SARS-CoV-2 infection in this immunocompromised population.

Resume Introduction L’angiopathie vasospastique idiopathique de l’artere carotide interne est une cause rare et mal connue d’accident vasculaire cerebral ischemique. Methodes Nous rapportons le cas d’un homme de 39 ans, migraineux, traite par betabloquants, qui presenta une baisse de vision de l’œil droit, des cephalees, puis une crise d’epilepsie generalisee tonicoclonique suivie d’une hemiparesie gauche. L’examen ophtalmologique revela une ischemie retinienne de l’œil droit et une hemianopsie laterale homonyme gauche incomplete. L’IRM montra une stenose allongee des deux carotides internes au niveau cervical et une ischemie sylvienne droit recente. Le diagnostic d’angiopathie vasospastique idiopathique de l’artere carotide interne fut pose grâce aux IRM de controle et un doppler des arteres cervicales, qui objectiverent la regression de la stenose carotidienne et l’absence d’hematome parietal. L’evolution clinique sous inhibiteur calcique et aspirine fut favorable. Les traitements vasoconstricteurs sont contre-indiques. Discussion/conclusion L’angiopathie vasospastique limitee aux carotides internes a ete peu documentee dans la litterature. Le role du terrain migraineux a ete evoque. L’etiologie peut etre meconnue, si l’exploration des vaisseaux du cou n’est pas precoce et renouvelee. Des recidives ont ete rapportees, justifiant pour certains auteurs un traitement specifique vasodilatateur en prevention secondaire. Les traitements vasoconstricteurs sont contre-indiques.

Neurosarcoidosis is a rare disease that can involve all the nervous system with variable clinical onset and prognosis. The initial therapeutic approach is mainly based on corticosteroids and immunosuppressive agents. Treatment of refractory forms of neurosarcoidosis is not well established and emerging immunomodulating drugs like infliximab have been recently tested. The clinical report of a new case of neurosarcoidosis responding to infliximab is followed by a review of the new therapeutic agents available for the treatment of refractory neurosarcoidosis.

Resume Le meningiome est une affection tumorale rare du nerf optique. La presentation clinique etant peu specifique et l’acces a l’anatomo-pathologie difficile, le diagnostic positif repose sur l’imagerie. Son traitement reste controverse. Nous rapportons notre experience de vingt-et-un cas de meningiome du nerf optique (MNO) chez vingt patients. La majorite de nos patients etaient des femmes, d’âge moyen 47 ans. Le MNO s’est revele le plus souvent par un trouble visuel. L’examen ophtalmologique etait generalement altere (acuite visuelle, champ visuel, fond d’œil). L’IRM centree sur le nerf optique, avec injection de gadolinium et saturation de la graisse orbitaire etait l’examen de choix pour le diagnostic. Un tiers des patients avaient un examen ophtalmologique stable au terme du suivi, sans traitement agressif. La radiotherapie fractionnee conformationnelle etait le seul traitement semblant susceptible d’ameliorer le pronostic fonctionnel. Ses indications et modalites restent a preciser.

Oscillopsia is an illusion of an unstable visual world. It is associated with poor visual acuity and is a disabling and stressful symptom reported by numerous patients with neurological disorders. The goal of this paper is to review the physiology of the systems subserving stable vision, the various pathophysiological mechanisms of oscillopsia and the different treatments available. Visual stability is conditioned by two factors. First, images of the seen world projected onto the retina have to be stable, a sine qua non condition for foveal discriminative function. Vestibulo-ocular and optokinetic reflexes act to stabilize the retinal images during head displacements; ocular fixation tends to limit the occurrence of micro ocular movements during gazing; a specific system also acts to maintain the eyes stable during eccentric gaze. Second, although we voluntary move our gaze (body, head and eye displacements), the visual world is normally perceived as stable, a phenomenon known as space constancy. Indeed, complex cognitive processes compensate for the two sensory consequences of gaze displacement, namely an oppositely-directed retinal drift and a change in the relationship between retinal and spatial (or subject-centered) coordinates of the visual scene. In patients, oscillopsia most often results from abnormal eye movements which cause excessive motion of images on the retina, such as nystagmus or saccadic intrusions or from an impaired vestibulo-ocular reflex. Understanding the exact mechanisms of impaired eye stability may lead to the different treatment options that have been documented in recent years. Oscillopsia could also result from an impairment of spatial constancy mechanisms that in normal condition compensate for gaze displacements, but clinical data in this case are scarce. However, we suggest that some visuo-perceptive deficits consecutive to temporo-parietal lesions resemble oscillopsia and could result from a deficit in elaborating spatial constancy.

We review the question of diagnosis of painful and relatively isolated ophthalmoplegia due to diseases affecting the ocular motor nerves. For each clinical setting, we provide an overview of the main causes and a practical way to approach the diagnosis. As vascular malformations should always be kept in mind in patients with painful ophthalmoplegia, emergency neuroradiological investigations may be needed. However, the etiological scope is wide and the rationale for choosing the more appropriate examination and its optimal timing depends exclusively on the clinical evaluation. Despite advances in investigation techniques, diagnosis may remain difficult or even unresolved in a certain number of patients. We discuss successively paralysis of the third, sixth and fourth nerve, paralysis of several ocular motor nerves, recurrent ophthalmoplegia and ischaemic ocular motor palsies, which are the most frequent cause.

We report the case of a 57-year-old man who presented bilateral subacute and painless optic neuropathy after meningopolyradiculitis revealing a primary human immunodeficiency virus infection. Both antiretroviral and steroid treatments were ineffective. Clinical symptoms and evolutive pattern were consistent with a mechanism of microvascular ischaemia of the optic nerve head. Optic neuropathies related to HIV infection are rare compared to those resulting from opportunistic infections. There are several pathophysiological mechanisms involved.

International audience; The cerebellum is critically involved in the adaptation mechanisms that maintain the accuracy of goaldirected acts such as saccadic eye movements. Two categories of saccades, each relying on different adaptation mechanisms, are defined: reactive (externally triggered) saccades and voluntary (internally triggered) saccades. The contribution of the medio-posterior part of the cerebellum to reactive saccades adaptation has been clearly demonstrated, but the evidence that other parts of the cerebellum are also involved is limited. Moreover, the cerebellar substrates ofvoluntary saccades adaptation have only been marginally investigated. Here, we addressed these two questions by investigating the adaptive capabilities of patients with cerebellar or pre-cerebellar stroke. We recruited three groups of patients presenting focal lesions located, respectively in the supero-anterior cerebellum, the infero-posterior cerebellum and the lateral medulla (leading to a Wallenberg syndrome including motor dysfunctions similar to those resulting from lesion of the medio-posterior cerebellum). Adaptations of reactive saccades and of voluntary saccades were tested during separate sessions in all patients and in a group of healthy participants. The functional lesion ofthe medio-posterior cerebellum in Wallenberg syndrome strongly impaired the adaptation of both reactive and voluntary saccades. In contrast, patients with lesion in the supero-anterior part of the cerebellum presented a specific adaptation deficit of voluntary saccades. Finally, patientswith an infero-posterior cerebellar lesion showed mild adaptation deficits. We conclude that the medio-posterior cerebellum is critical for the adaptation of both saccade categories, whereas the supero-anterior cerebellum is specifically involved in the adaptation of voluntary saccades.

Sensory-motor adaptation processes are critically involved in maintaining accurate motor behavior throughout life. Yet their underlying neural substrates and task-dependency bases are still poorly understood. We address these issues here by studying adaptation of saccadic eye movements, a well-established model of sensory-motor plasticity. The cerebellum plays a major role in saccadic adaptation but it has not yet been investigated whether this role can account for the known specificity of adaptation to the saccade type (e.g., reactive versus voluntary). Two patients with focal lesions in different parts of the cerebellum were tested using the double-step target paradigm. Each patient was submitted to two separate sessions: one for reactive saccades (RS) triggered by the sudden appearance of a visual target and the second for scanning voluntary saccades (SVS) performed when exploring a more complex scene. We found that a medial cerebellar lesion impaired adaptation of reactive-but not of voluntary-saccades, whereas a lateral lesion affected adaptation of scanning voluntary saccades, but not of reactive saccades. These findings provide the first evidence of an involvement of the lateral cerebellum in saccadic adaptation, and extend the demonstrated role of the cerebellum in RS adaptation to adaptation of SVS. The double dissociation of adaptive abilities is also consistent with our previous hypothesis of the involvement in saccadic adaptation of partially separated cerebellar areas specific to the reactive or voluntary task (Alahyane et al. Brain Res 1135:107-121 (2007)).

International audience; OBJECTIVE: To determine the effect of subthalamic stimulation on visually triggered eye and head movements in patients with Parkinson's disease (PD). METHODS: We compared the gain and latency of visually triggered eye and head movements in 12 patients bilaterally implanted into the subthalamic nucleus (STN) for severe PD and six age-matched control subjects. Visually triggered movements of eye (head restrained), and of eye and head (head unrestrained) were recorded in the absence of dopaminergic medication. Bilateral stimulation was turned OFF and then turned ON with voltage and contact used in chronic setting. The latency was determined from the beginning of initial horizontal eye movements relative to the target onset, and the gain was defined as the ratio of the amplitude of the initial movement to the amplitude of the target movement. RESULTS: Without stimulation, the initiation of the head movement was significantly delayed in patients and the gain of head movement was reduced. Our patients also presented significantly prolonged latencies and hypometry of visually triggered saccades in the head-fixed condition and of gaze in head-free condition. Bilateral STN stimulation with therapeutic parameters improved performance of orienting gaze, eye and head movements towards the controls' level CONCLUSIONS: These results demonstrate that visually triggered saccades and orienting eye-head movements are impaired in the advanced stage of PD. In addition, subthalamic stimulation enhances amplitude and shortens latency of these movements. SIGNIFICANCE: These results are likely explained by alteration of the information processed by the superior colliculus (SC), a pivotal visuomotor structure involved in both voluntary and reflexive saccades. Improvement of movements with stimulation of the STN may be related to its positive input either on the STN-Substantia Nigra-SC pathway or on the parietal cortex-SC pathway.

International audience; Contraversive eye deviation (CED) is most often observed intraoperatively during subthalamic nucleus implantation for Parkinson's disease and considered to result from wrong electrode positioning. We report on a woman, bilaterally implanted in the subthalamic nucleus for severe Parkinson's disease disclosing long-lasting CED only when the stimulators were activated separately. Clinical examination and eye movements recording in this patient showed that CED occurred when stimulation was applied at the site and at similar intensity used for the best antiparkinsonian effect. These results suggest that the subthalamic area may be involved in orienting movements, either through the subthalamic nucleus itself or the fibers from the Frontal Eye Fields. Interestingly, this report shows that CED may be corrected by bilateral stimulation and that CED may not necessarily implicate electrode repositioning.