Congenital Myasthenic Syndromes in Belgium: Genetic and Clinical Characterization of Pediatric and Adult Patients.

Background: Congenital myasthenic syndromes (CMS) are a group of genetic disorders characterized by impaired neuromuscular transmission. CMS typically present at a young age with fatigable muscle weakness, often with an abnormal response after repetitive nerve stimulation (RNS). Pharmacologic treatment can improve symptoms, depending on the underlying defect.

Early-Onset Autosomal Dominant Myopathy with Vacuolated Fibers and Tubular Aggregates but No Periodic Paralysis, in a Patient with the c.1583G>A (p.R528H) mutation in the CACNA1S Gene.

Dominant mutations in CACNA1S gene mainly causes hypokalemic periodic paralysis (PP)(hypoPP). A 68-year-old male proband developed a progressive proximal weakness from the age of 35. Muscle biopsy showed atrophic fibers with vacuoles containing tubular aggregates.

Lessons for future clinical trials in adults with Becker muscular dystrophy: Disease progression detected by muscle magnetic resonance imaging, clinical and patient-reported outcome measures.

Background And Purpose: Because Becker muscular dystrophy (BMD) is a heterogeneous disease and only few studies have evaluated adult patients, it is currently still unclear which outcome measures should be used in future clinical trials.

Methods: Muscle magnetic resonance imaging, patient-reported outcome measures and a wide range of clinical outcome measures, including motor function, muscle strength and timed-function tests, were evaluated in 21 adults with BMD at baseline and at 9 and 18 months of follow-up.

Results: Proton density fat fraction increased significantly in 10/17 thigh muscles after 9 months, and in all thigh and lower leg muscles after 18 months.

A First Case of Acute Flaccid Myelitis Related to Enterovirus D68 in Belgium: Case Report.

Introduction: We describe the first case of acute flaccid myelitis (AFM) related to enterovirus D68 (EV-D68) infection in Belgium. The clinical and radiological presentation of AFM associated with EV-D68 although well described currently remains a challenging diagnosis. Through this interesting clinical case, we aimed to review the differential diagnosis of acute flaccid palsy in a child and discuss the specific point of interest related to AFM.

A pathogenic CTBP1 variant featuring HADDTS with dystrophic myopathology.

HADDTS (Hypotonia, Ataxia, Developmental-Delay and Tooth-enamel defects) is a newly emerging syndrome caused by CTBP1 mutations. Only five reports (13 cases) are available; three contained muscle-biopsy results but none presented illustrated histomyopathology. We report a patient in whom whole-exome sequencing revealed a heterozygous de novo CTBP1 missense mutation (c.

A retrospective survey of patients with hereditary transthyretin-mediated (hATTR) amyloidosis treated with patisiran in real-world clinical practice in Belgium.

Introduction: Hereditary transthyretin-mediated (hATTR) amyloidosis, a genetic disease caused by mutations in the transthyretin gene, leads to progressive sensory and autonomic neuropathy and/or cardiomyopathy and is associated with renal and ophthalmologic manifestations and a poor prognosis.

Methods: This is a retrospective study based on data collected from the medical records of patients with hATTR amyloidosis treated with patisiran between 01 July 2018 and 01 February 2021. Six Belgian neuromuscular reference centers participated, covering all patisiran-treated hATTR amyloidosis patients at the study time.

Telemedicine in Neuromuscular Diseases During Covid-19 Pandemic: ERN-NMD European Survey.

Background: Telemedicine (TM) contributes to bridge the gap between healthcare facilities and patients' homes with neuromuscular disease (NMD) because of mobility issues. However, its deployment is limited due to difficulties evaluating subtle neurological signs such as mild weakness or sensory deficits. The COVID-19 pandemic has disrupted healthcare delivery worldwide, necessitating rapid measures implementation by health care providers (HCPs) to protect patients from acquiring SARS-CoV-2 while maintaining the best care and treatment.

Rituximab Responsive Relapsing-Remitting IgG4 Anticontactin 1 Chronic Inflammatory Demyelinating Polyradiculoneuropathy Associated With Membranous Nephropathy: A Case Description and Brief Review.

Nodal/paranodal IgG4-related chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) rarely involves anticontactin (CNTN1) subtype and exceptionally complicates with nephrotic syndrome. A 65-year-old man developed weakness, facial palsy, and balance impairment; after spontaneous recovery, he severely relapsed 1 month later. Electroneuromyography confirmed CIDP.

RFC1 repeat expansions: A recurrent cause of sensory and autonomic neuropathy with cough and ataxia.

Background And Purpose: Ataxia and cough are rare features in hereditary sensory and autonomic neuropathies (HSAN), a group of diseases of mostly unknown genetic cause. Biallelic repeat expansions in RFC1 are associated with cerebellar ataxia, neuropathy, and vestibular areflexia syndrome (CANVAS). This study aimed to investigate the prevalence of RFC1 repeat expansions in a cohort of HSAN patients.

SPG43 and ALS-like syndrome in the same family due to compound heterozygous mutations of the C19orf12 gene: a case description and brief review.

C19orf12 gene biallelic mutations lead mainly to neurodegeneration with brain iron accumulation-4. A 15-year-old male and his 17-year-old sister complained of cramps and exercise intolerance. Clinical examination of the boy mainly showed distal amyotrophy and mild weakness, while the sister predominantly had a tetrapyramidal syndrome.

Acute Paraparesis after Epidural Corticosteroid Injection Revealing Spinal Dural Arteriovenous Fistula in a HIV Patient.

Unlabelled: Spinal dural arteriovenous fistulas (SDAVFs) are often misdiagnosed as their symptoms are non-specific, leading to treatment delay and a poor outcome. We describe the case of a 53-year-old man with a history of progressive paraparesis that worsened abruptly after an epidural corticosteroid injection. We highlight here the need for high diagnostic suspicion for an SDAVF in patients deteriorating after an epidural injection and an indication of repeated spine imaging in such cases.

Corpus callosum thinning in autosomal dominant hereditary spastic paraplegia associated with a novel TUBβ4A mutation.

Siblings with hereditary spastic paraplegia and corpus callosum thinning associated with a novel TUBβ4A mutation.

Antibodies against the node of Ranvier: a real-life evaluation of incidence, clinical features and response to treatment based on a prospective analysis of 1500 sera.

Introduction: IgG4 antibodies against neurofascin (Nfasc155 and Nfasc140/186), contactin (CNTN1) and contactin-associated protein (Caspr1) are described in specific subtypes of chronic inflammatory demyelinating polyradiculoneuropathy (CIDP). Our objective was to assess, in a real-life practice, the incidence, the clinical features and the response to treatment of these forms of CIDP.

Methods: 1500 sera of patients suspected of having CIDP from France, Belgium and Switzerland were prospectively tested using a flow cytometry technique.

Cerebellar ataxia, neuropathy, hearing loss, and intellectual disability due to AIFM1 mutation.

Objective: To describe the clinical and molecular genetic findings in a family segregating a novel mutation in the gene on the X chromosome.

Methods: We studied the clinical features and performed brain MRI scans, nerve conduction studies, audiometry, cognitive testing, and clinical exome sequencing (CES) in the proband, his mother, and maternal uncle. We used in silico tools, X chromosome inactivation assessment, and Western blot analysis to predict the consequences of an variant identified by CES and demonstrate its pathogenicity.

Low Prevalence Estimates of Late-Onset Glycogen Storage Disease Type II in French-Speaking Belgium are not Due to Missed Diagnoses.

Background: Late-onset glycogen storage disease type II is associated with variable muscle phenotypes. Epidemiological data suggest that its prevalence is lower in Belgium than in bordering countries like The Netherlands.

Objective: We investigated whether such low estimated prevalence is due to missed diagnoses.

Impact of hyponatremia on nerve conduction and muscle strength.

Background: Hyponatremia is associated with unstable gait and propensity to falls. The potential contribution of peripheral nervous system dysfunction induced by hyponatremia has not yet been addressed by prospective studies.

Design: In the first part of this prospective study, we performed two tests evaluating muscle strength (grip test and quadriceps isometric contraction test) together with a timed up and go (TUG) test in 11 patients with chronic mild-to-moderate hyponatremia before and after the normalization of natremia.

A novel large deletion in the RYR1 gene in a Belgian family with late-onset and recessive core myopathy.

We report a novel and particularly unusual type of mutation, namely, large deletion in the RYR1 gene, in a Belgian family with myopathy: Patients were found to be compound heterozygous and presented a clinico-pathological phenotype characterized by late-onset and recessive myopathy with cores. We depict the clinical, electrophysiological, pathological and molecular genetic characteristics of family members. To date, large deletions in the RYR1 gene have been reported in only two cases.

Extended phenotype description and new molecular findings in late onset glycogen storage disease type II: a northern Italy population study and review of the literature.

Glycogen storage disease type II (GSDII) is a lysosomal storage disorder caused by acid alpha-1,4-glucosidase deficiency and associated with recessive mutations in its coding gene GAA. Few studies have provided so far a detailed phenotypical characterization in late onset GSDII (LO-GSDII) patients. Genotype-phenotype correlation has been previously attempted with controversial results.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) associated to hereditary neuropathy with liability to pressure palsies (HNPP) and revealed after influenza AH1N1 vaccination.

Neurological complications of AH1N1 vaccination such as Guillain-Barré syndrome were described in the previous years. Several reports suggest that hereditary neuropathies may be a predisposing factor for immune-mediated neuropathies. We report the case of a 54-year-old female who developed chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) 5 weeks after AH1N1 vaccination.

Screening for later-onset Pompe's disease in patients with paucisymptomatic hyperCKemia.

Background: Pompe's disease is an inherited metabolic myopathy caused by acid α-glucosidase deficiency. Early diagnosis optimizes the treatment effectiveness.

Methods: One-hundred-thirty-seven consecutive patients with unexplained hyperCKemia underwent the assessment of acid α-glucosidase activity on dried blood spot.

Postural effects on lung and chest wall volumes in late onset type II glycogenosis patients.

Respiratory failure associated with diaphragmatic weakness is the first cause of death in late-onset type II glycogenosis (LO-GSDII). We aim to identify predictive factors of diaphragmatic weakness and investigate the pathophysiology of respiratory muscles impairment. Pulmonary function and chest wall volumes were measured in ten patients and eight controls (supine and seated).