The new missense G376V-TDP-43 variant induces late-onset distal myopathy but not amyotrophic lateral sclerosis.

TAR DNA binding protein of 43 kDa (TDP-43)-positive inclusions in neurons are a hallmark of several neurodegenerative diseases including familial amyotrophic lateral sclerosis (fALS) caused by pathogenic TARDBP variants as well as more common non-Mendelian sporadic ALS (sALS). Here we report a G376V-TDP-43 missense variant in the C-terminal prion-like domain of the protein in two French families affected by an autosomal dominant myopathy but not fulfilling diagnostic criteria for ALS. Patients from both families presented with progressive weakness and atrophy of distal muscles, starting in their fifth to seventh decade.

Myasthenia gravis treatment in the elderly presents with a significant iatrogenic risk: a multicentric retrospective study.

Background: Myasthenia gravis (MG) is an autoimmune disease treated with acetylcholinesterase inhibitors and immunosuppressant/immunomodulatory drugs. MG is frequently diagnosed in elderly patients, a fragile population in which treatment adverse effects (TAE) have not been evaluated until now.

Methods: We retrospectively analysed the files of all MG patients with disease onset after age 70 years in four French University Hospitals, including clinical, electrophysiological, biological, and treatment data, with an emphasis on TAE.

Peripheral nervous system involvement accompanies central nervous system involvement in anti-glial fibrillary acidic protein (GFAP) antibody-related disease.

Background: Glial fibrillary acidic protein (GFAP) is expressed by astrocytes in the central nervous system (CNS), but also by immature and regenerative Schwann cells in the peripheral nervous system (PNS). GFAP antibodies (GFAP-Abs) in cerebrospinal fluid (CSF) have been mainly described in patients with meningoencephalomyelitis. We aimed to study PNS symptoms in patients with CSF GFAP-Abs.

Inaugural dropped head syndrome and camptocormia in inflammatory myopathies: a retrospective study.

Objectives: Inaugural axial muscle involvement, defined as dropped head syndrome (DHS) and/or camptocormia (CC), is poorly described in inflammatory myopathies (IM). This study aimed to further characterize IM patients with inaugural DHS/CC, their outcome and care management.

Methods: This retrospective study included IM patients diagnosed between 2000 and 2021.

Usefulness and prognostic value of diagnostic tests in patients with possible chronic inflammatory demyelinating polyradiculoneuropathy.

Introduction/aims: Recent guidelines define chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) and possible CIDP. The aims of our study were to evaluate the value of diagnostic tests to support the diagnosis of CIDP in patients with possible CIDP and to identify prognostic factors of therapeutic success.

Methods: We conducted an observational retrospective two-center study between 2014 and 2019.

Charcot-Marie-Tooth disease type 2CC due to variants causes a progressive, non-length-dependent, motor-predominant phenotype.

Objective: Neurofilaments are the major scaffolding proteins for the neuronal cytoskeleton, and variants in have recently been described to cause axonal Charcot-Marie-Tooth disease type 2CC (CMT2CC).

Methods: In this large observational study, we present phenotype-genotype correlations on 30 affected and 3 asymptomatic mutation carriers from eight families.

Results: The majority of patients presented in adulthood with motor-predominant and lower limb-predominant symptoms and the average age of onset was 31.

Clinical and Molecular Spectrum Associated with COL6A3 c.7447A>G p.(Lys2483Glu) Variant: Elucidating its Role in Collagen VI-related Myopathies.

Background: Dominant and recessive autosomal pathogenic variants in the three major genes (COL6A1-A2-A3) encoding the extracellular matrix protein collagen VI underlie a group of myopathies ranging from early-onset severe conditions (Ullrich congenital muscular dystrophy) to milder forms maintaining independent ambulation (Bethlem myopathy). Diagnosis is based on the combination of clinical presentation, muscle MRI, muscle biopsy, analysis of collagen VI secretion, and COL6A1-A2-A3 genetic analysis, the interpretation of which can be challenging.

Objective: To refine the phenotypical spectrum associated with the frequent COL6A3 missense variant c.

Genotype-phenotype correlations in recessive titinopathies.

Purpose: High throughput sequencing analysis has facilitated the rapid analysis of the entire titin (TTN) coding sequence. This has resulted in the identification of a growing number of recessive titinopathy patients. The aim of this study was to (1) characterize the causative genetic variants and clinical features of the largest cohort of recessive titinopathy patients reported to date and (2) to evaluate genotype-phenotype correlations in this cohort.

Development and Validation of a New Risk Prediction Score for Life-Threatening Ventricular Tachyarrhythmias in Laminopathies.

Background: An accurate estimation of the risk of life-threatening (LT) ventricular tachyarrhythmia (VTA) in patients with LMNA mutations is crucial to select candidates for implantable cardioverter-defibrillator implantation.

Methods: We included 839 adult patients with LMNA mutations, including 660 from a French nationwide registry in the development sample, and 179 from other countries, referred to 5 tertiary centers for cardiomyopathies, in the validation sample. LTVTA was defined as (1) sudden cardiac death or (2) implantable cardioverter defibrillator-treated or hemodynamically unstable VTA.

A new MRI marker of ataxia with oculomotor apraxia.

Purpose: Evaluate the specificity and sensitivity of disappearance of susceptibility weighted imaging (SWI) dentate nuclei (DN) hypointensity in oculomotor apraxia patients (AOA).

Method: In this prospective study, 27 patients with autosomal genetic ataxia (AOA (n = 11), Friedreich ataxia and ataxia with vitamin E deficit (n = 4), and dominant genetic ataxia (n = 12)) were included along with fifteen healthy controls. MRIs were qualitatively classified for the presence or absence of DN hypointensity on FLAIR and SWI sequences.

Focal myositis: New insights on diagnosis and pathology.

Objective: To better define in a cohort study the clinical and pathologic features of focal myositis (FM).

Methods: With the use of the usual clinicopathologic definition, each confirmed case of FM in the Lyon University Hospital's myopathologic database between 2000 and 2016 was retrieved. Clinical, pathologic, imaging, serologic, and therapeutic data were collected.

Renal Involvement in Neuropathy, Ataxia, Retinitis Pigmentosa (NARP) Syndrome: A Case Report.

We report a case of a patient who had the mitochondrial cytopathy complex of neuropathy, ataxia, and retinitis pigmentosa (NARP) syndrome diagnosed at age 11 years with a biopsy-proven kidney involvement that progressed to end-stage renal disease at age 21 years. Mutations of mitochondrial DNA (mtDNA) are maternally inherited and lead to mitochondrial cytopathies with predominant neurologic manifestations: psychomotor retardation, epilepsy, ataxia, neuropathy, and myopathy. Given the ubiquitous nature of mitochondria, cellular dysfunction can also appear in tissues with high metabolic turnover; thus, there can be cardiac, digestive, ophthalmologic, and kidney complications.

Anti-MAG antibodies in 202 patients: clinicopathological and therapeutic features.

Objective: To assess the clinicopathological and therapeutic features of patients with low (≥1000 to <10 000 Bühlmann Titre Units) (BTU), medium (10 000-70 000) or high (≥70 000) anti-myelin-associated glycoprotein (anti-MAG) antibody titres.

Methods: We retrospectively and prospectively analysed standardised report forms and medical records of 202 patients from 14 neuromuscular centres.

Results: Mean age at onset and mean time between symptom onset to last follow-up were respectively 62.

Axonal Neuropathies due to Mutations in Small Heat Shock Proteins: Clinical, Genetic, and Functional Insights into Novel Mutations.

In this study, we describe the phenotypic spectrum of distal hereditary motor neuropathy caused by mutations in the small heat shock proteins HSPB1 and HSPB8 and investigate the functional consequences of newly discovered variants. Among 510 unrelated patients with distal motor neuropathy, we identified mutations in HSPB1 (28 index patients/510; 5.5%) and HSPB8 (four index patients/510; 0.

SWORD: A simplified desensitization protocol for enzyme replacement therapy in adult Pompe disease.

Pompe disease is an inherited lysosomal disease in which there is a decrease or absence of acid alpha-glucosidase activity. This enzyme defect induces glycogen storage in different tissues, especially muscle and heart, resulting in muscle weakness, respiratory failure and heart disease. Substitutive enzyme replacement therapy (ERT) dispensed every two weeks is the only treatment that has shown benefits.

Diagnostic utility of somatosensory evoked potentials in chronic polyradiculopathy without electrodiagnostic signs of peripheral demyelination.

Introduction: Diagnosis of chronic inflammatory demyelinating polyneuropathy (CIDP) remains uncertain when nerve conduction studies (NCS) fail to show demyelination.

Methods: We conducted a retrospective study of patients who presented with clinical criteria of CIDP in whom electrodiagnostic (EDx) criteria of definite or probable CIDP were missing [axonal sensorimotor neuropathy (n = 23), normal EDx with pure sensory presentation (n = 3)]. All patients received immunomodulatory treatment.