Electrophysiological Abnormalities in Finger Extension Weakness and DOwnbeat Nystagmus Motor Neuron Disease: Three New Patients and Review of the Literature.

Introduction/aims: Finger Extension Weakness and DOwnbeat Nystagmus Motor Neuron Disease (FEWDON-MND) is characterized by motor weakness predominantly affecting finger extension, accompanied by downbeat nystagmus. To date, only 11 patients have been reported. The present study adds a further three and aims to provide a more detailed description of the electrodiagnostic features of these patients.

Use of assistive technology to assess distal motor function in subjects with neuromuscular disease.

Unlabelled: Among the 32 items of the Motor Function Measure scale, 3 concern the assessment of hand function on a paper-based support. Their characteristics make it possible to envisage the use of a tablet instead of the original paper-based support for their completion. This would then make it possible to automate the score to reduce intra- and inter-individual variability.

Demyelinating neuropathy as the initial presentation of familial E200K Creutzfeldt-Jakob disease in two patients.

Objective: To describe peripheral neuropathy associated with familial Creutzfeldt-Jakob disease.

Methods: We report two unrelated patients with genetic Creutzfeldt-Jakob disease with demyelinating peripheral neuropathy as initial presentation, with a comprehensive clinical, electrophysiological and neuropathological description.

Results: Both patients exhibited gait disturbance and paresthesia.

Clinical and Electrophysiological Characteristics of 23 French Patients With Neurolymphomatosis.

Introduction/aims: Neurolymphomatosis is a hematological condition defined by the direct infiltration of malignant lymphomatous cells into the peripheral nervous system. Since nerve conduction studies may disclose demyelinating features, clinicians may misdiagnose neurolymphomatosis as chronic inflammatory demyelinating polyneuropathy (CIDP). This study aimed to determine whether patients with neurolymphomatosis met the 2021 revised criteria for CIDP.

Spinal muscular atrophy is also a disorder of spermatogenesis.

Background: Spinal muscular atrophy (SMA) patients benefit from pre-mRNA splicing modifiers targeting the SMN2 gene, which aims to increase functional SMN production. The animal toxicity affecting spermatogenesis associated with one such treatment raised questions about male SMA patients' spermatogenesis.

Methods: This descriptive, cross-sectional study was conducted from June 2022 to July 2023.

-related myopathies: clinical, myopathological and genotypic spectrum in a multicentre French cohort.

Background: Myosin heavy chain 7 ()-related myopathies (-RMs) are a group of muscle disorders linked to pathogenic variants in the gene, encoding the slow/beta-cardiac myosin heavy chain, which is highly expressed in skeletal muscle and heart. The phenotype is heterogeneous including distal, predominantly axial or scapuloperoneal myopathies with variable cardiac involvement.

Methods: We retrospectively analysed the clinical, muscle MRI, genetic and myopathological features of 57 patients.

Treatment of myasthenia gravis in france: A retrospective claims database study (STAMINA).

Background: This study aimed to describe treatment patterns in patients with myasthenia gravis (MG) in France.

Methods: A retrospective cohort analysis was performed using the French National Health Data System (SNDS) database between 2008 and 2019. MG patients were identified using ICD-10 codes during hospitalization and/or long-term disease.

Defining the landscape of TIA1 and SQSTM1 digenic myopathy.

TIA1/SQSTM1 myopathy is one of the few digenic myopathies. We describe four new French adult male patients carrying the TIA1 p.Asn357Ser and SQSTM1 p.

Identification of rare variants in the FBXO38 gene of patients with chronic inflammatory demyelinating polyradiculoneuropathy.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is a rare immune-mediated neuropathy for which there is no clearly identified risk factor. The present study identified rare variants in the FBXO38 gene in three familial cases of CIDP with response to corticosteroids in three generations with incomplete penetrance, and in an unrelated fourth case with diffuse nerve hypertrophy. FBXO38 may be involved in the regulation of the immunity mediated by CD8 T cells, which have an important role in CIDP pathophysiology, through PD1 degradation.

A previously unreported NARS1 variant causes dominant distal hereditary motor neuropathy in a French family.

Background And Aims: Pathogenic variants in the NARS1 gene, which encodes for the asparaginyl-tRNA synthetase1 (NARS1) enzyme, were associated with complex central and peripheral nervous system phenotypes. Recently, Charcot-Marie-Tooth (CMT) disease has been linked to heterozygous pathogenic variants in NARS1 in nine patients. Here, we report two brothers and their mother from a French family with distal hereditary motor neuropathy (dHMN) carrying a previously unreported NARS1 variant.

Electrophysiological abnormalities of the neuromuscular transmission in two patients with botulism-like syndrome following Botulinum-A muscle injections.

Botulinum neurotoxin serotype A (BoNT-A) has several therapeutic indications such as spasticity and dystonia. Although its use is generally considered safe, a systemic diffusion can lead to systemic complications, and a botulism-like syndrome can occur after intramuscular injections. Herein, two adult cases who developed general muscle weakness after a BoNT-A intramuscular injection are reported.

Primary mitochondrial disorders and mimics: Insights from a large French cohort.

Objective: The objective of this study was to evaluate the implementation of NGS within the French mitochondrial network, MitoDiag, from targeted gene panels to whole exome sequencing (WES) or whole genome sequencing (WGS) focusing on mitochondrial nuclear-encoded genes.

Methods: Over 2000 patients suspected of Primary Mitochondrial Diseases (PMD) were sequenced by either targeted gene panels, WES or WGS within MitoDiag. We described the clinical, biochemical, and molecular data of 397 genetically confirmed patients, comprising 294 children and 103 adults, carrying pathogenic or likely pathogenic variants in nuclear-encoded genes.

Expert opinion on mexiletine treatment in adult patients with myotonic dystrophy.

In France, mexiletine - a class I antiarrhythmic drug - can be prescribed for the symptomatic treatment of myotonia of the skeletal muscles in adult patients with myotonic dystrophy under a compassionate use programme. Mexiletine is used according to its summary of product characteristics, which describes its use for myotonia treatment in adult patients with non-dystrophic myotonia, a different neuromuscular condition without cardiac involvement. A cardiac assessment is required prior to initiation and throughout treatment due to potential proarrhythmic effects.

Neurological autoimmunity in melanoma patients: a comparison between those exposed and non-exposed to immune checkpoint inhibitors.

Background: The clinical spectrum of melanoma-associated neurological autoimmunity, whether melanoma-associated paraneoplastic neurological syndromes (PNS) or induced by immune checkpoint inhibitors (ICI), is not well characterized. We aim to describe the clinical spectrum of melanoma-associated neurological autoimmunity.

Methods: A systematic review of the literature combined with patients from French databases of paraneoplastic neurological syndromes was conducted.

Retrospective clinical and genetic analysis of COL6-RD patients with a long-term follow-up at a single French center.

Collagen type VI-related dystrophies (COL6-RD) are rare diseases with a wide phenotypic spectrum ranging from severe Ullrich's congenital muscular dystrophy Ullrich congenital muscular dystrophy to much milder Bethlem myopathy Both dominant and recessive forms of COL6-RD are caused by pathogenic variants in three collagen VI genes (, and ). The prognosis of these diseases is variable and difficult to predict during early disease stages, especially since the genotype-phenotype correlation is not always clear. For this reason, studies with long-term follow-up of patients with genetically confirmed COL6-RD are still needed.

Epidemiology of myasthenia gravis in France: A retrospective claims database study (STAMINA).

Background: The objectives of this observational study were to report the incidence and prevalence of myasthenia gravis (MG) in France, describe patients' characteristics and treatment patterns, and estimate mortality.

Methods: A historical cohort analysis was performed using the French National Health Data System (SNDS) database between 2008 and 2020. Patients with MG were identified based on ICD-10 codes during hospitalization and/or long-term disease (ALD) status, which leads to a 100% reimbursement for healthcare expenses related to MG.