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Neurofibromatosis type 1 (NF1) is one of the most frequent monogenetic disorders. It can be associated with cognitive dysfunctions in several domains such as executive functioning, language, visual perception, motor skills, social skills, memory and/or attention. Neuroimaging is becoming more and more important for a clearer understanding of the neural basis of these deficits. In recent years, several studies have used different imaging techniques to examine structural, morphological and functional alterations in NF1 disease. They have shown that NF1 patients have specific brain characteristics such as Unidentified Bright Objects (UBOs), macrocephaly, a higher volume of subcortical structures, microstructure integrity alterations, or connectivity alterations. In this review, which focuses on the studies published after the last 2 reviews of this topic (in 2010 and 2011), we report on recent structural, morphological and functional neuroimaging studies in NF1 subjects, with special focus on those that examine the neural basis of the NF1 cognitive phenotype. Although UBOs are one of the most obvious and visible elements in brain imaging, correlation studies have failed to establish a robust and reproducible link between major cognitive deficits in NF1 and their presence, number or localization. In the same vein, the results among structural studies are not consistent. Functional magnetic resonance imaging (fMRI) studies appear to be more sensitive, especially for understanding the executive function deficit that seems to be associated with a dysfunction in the right inferior frontal areas and the middle frontal areas. Similarly, fMRI studies have found that visuospatial deficits could be associated with a dysfunction in the visual cortex and especially in the magnocellular pathway involved in the processing of low spatial frequency and high temporal frequency. Connectivity studies have shown a reduction in anterior-posterior "long-range" connectivity and a deficit in deactivation in default mode network (DMN) during cognitive tasks. In conclusion, despite the contribution of new imaging techniques and despite relative advancement, the cognitive phenotype of NF1 patients is not totally understood., (Copyright © 2020 Baudou, Nemmi, Biotteau, Maziero, Peran and Chaix.)

Introduction: Guillain-Barré syndrome (GBS) is an inflammatory polyradiculoneuritis. Our aim in this study was to describe the clinical characteristics and the long-term sequelae of GBS in a French pediatric population., Methods: In this multicenter, retrospective study we evaluated clinical signs, radiological examinations, laboratory tests, treatments, and outcomes., Results: One hundred ten children were included in this investigation. These children presented with walking difficulties, muscle weakness, and cranial nerve impairment. Electrodiagnostic testing revealed 70% with acute inflammatory demyelinating polyradiculoneuropathy (AIDP) and 16% with acute motor axonal neuropathy (AMAN). One hundred children received immunoglobulins. At follow-up, 77% were cured, whereas 9% had sequelae, associated with an axonal form (P < .01) and a short interval between symptom onset and hospitalization (P < .01). The need for intubation was correlated with peripheral facial paralysis (P < .01) and dysautonomia (P < .01)., Discussion: Although AIDP and AMAN present in a similar way, the axonal form is associated with a worse outcome., (© 2019 Wiley Periodicals, Inc.)

Opso-myoclonus syndrome (OMS) is a very rare and severe condition. Ataxia, opsoclonus, myoclonus and/or behavioral and sleeping disturbances define that autoimmune disorder syndrome which is paraneoplastic or triggered by an infection. Here, we report a 3 year-old immunocompetent boy who developed an atypical OMS which was later complicated by an acute transverse myelitis. Screening for neuroblastoma was negative and extensive infectious screening revealed an active HHV-6 infection confirmed by blood and cerebrospinal fluid PCR. A parainfectious disease was suggested and immunosuppressive treatment was initiated. After 2 years of follow-up, the patient has a left leg paresia needing a splint and is otherwise normal. Transverse myelitis can be associated with parainfectious OMS and earlier immunosuppressive treatment in these cases may be useful especially in young and immunocompetent children., (Copyright © 2018 European Paediatric Neurology Society. Published by Elsevier Ltd. All rights reserved.)