Digenic inheritance involving a muscle-specific protein kinase and the giant titin protein causes a skeletal muscle myopathy.

In digenic inheritance, pathogenic variants in two genes must be inherited together to cause disease. Only very few examples of digenic inheritance have been described in the neuromuscular disease field. Here we show that predicted deleterious variants in SRPK3, encoding the X-linked serine/argenine protein kinase 3, lead to a progressive early onset skeletal muscle myopathy only when in combination with heterozygous variants in the TTN gene.

Small fiber involvement is independent from clinical pain in late-onset Pompe disease.

Background: Pain occurs in the majority of patients with late onset Pompe disease (LOPD) and is associated with a reduced quality of life. The aim of this study was to analyse the pain characteristics and its relation to a small nerve fiber involvement in LOPD patients.

Methods: In 35 patients with LOPD under enzyme replacement therapy without clinical signs of polyneuropathy (19 females; 51 ± 15 years), pain characteristics as well as depressive and anxiety symptoms were assessed using the PainDetect questionnaire (PDQ) and the hospital anxiety and depression scale (HADS), respectively.

Neurological outcomes 1 year after COVID-19 diagnosis: A prospective longitudinal cohort study.

Background And Purpose: Neurological sequelae from coronavirus disease 2019 (COVID-19) may persist after recovery from acute infection. Here, the aim was to describe the natural history of neurological manifestations over 1 year after COVID-19.

Methods: A prospective, multicentre, longitudinal cohort study in COVID-19 survivors was performed.

Signs of sympathetic and endothelial cell activation in the skin of patients with restless legs syndrome.

Objectives: To evaluate skin biopsies of patients with early- and late onset restless legs syndrome (RLS) for concomitant small fiber neuropathy (SFN) and to determine cutaneous sympathetic innervation and microvascularization in comparison to healthy individuals.

Methods: Density of intraepidermal nerve fibers (IENFD), adrenergic nerve fibers and dermal capillaries was analyzed by immunofluorescence for PGP9.5, tyrosine hydroxylase and endothelial markers CD31 and CD105 in skin biopsies of 11 individuals with RLS and 8 age- and sex-matched controls.

Muscle involvement in SARS-CoV-2 infection.

Background And Purpose: Since the outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic, several reports indicated neurological involvement in COVID-19 disease. Muscle involvement has also been reported as evidenced by creatine kinase (CK) elevations and reports of myalgia.

Methods: Creatine kinase, markers of inflammation, pre-existing diseases and statin use were extracted from records of Austrian hospitalised COVID-19 patients.

Laboratory Tests for Neuropathies: What to do and to Avoid.

Objectives: laboratory tests for work-up of hereditary and acquired neuropathies of peripheral nerves are frequently uncritically utilized. This overview focuses on the most common laboratory tests and investigations needed for diagnosing PNPs by the general neurologist.

Method: Literature search.

Pattern of myogenesis and vascular repair in early and advanced lesions of juvenile dermatomyositis.

Regenerative processes that counteract perifascicular muscle atrophy and capillary loss in juvenile dermatomyositis (JDM) are not well characterized. We aimed to analyze the pattern of myo-regeneration in relation to vascular damage and repair in muscle specimens from JDM patients. Myogenic regulatory factors that are sequentially expressed during myogenesis were studied by immunohistochemistry.

Expression of myogenic regulatory factors and myo-endothelial remodeling in sporadic inclusion body myositis.

Muscle repair relies on coordinated activation and differentiation of satellite cells, a process that is unable to counterbalance progressive degeneration in sporadic inclusion body myositis (s-IBM). To explore features of myo regeneration, the expression of myogenic regulatory factors Pax7, MyoD and Myogenin and markers of regenerating fibers was analyzed by immunohistochemistry in s-IBM muscle compared with polymyositis, dermatomyositis, muscular dystrophy and age-matched controls. In addition, the capillary density and number of interstitial CD34(+) hematopoietic progenitor cells was determined by double-immunoflourescence staining.

Endothelial and myogenic differentiation of hematopoietic progenitor cells in inflammatory myopathies.

Incorporation of circulating hematopoietic progenitor cells (HPCs) into damaged skeletal muscle has been proposed as a novel mechanism of tissue repair complementary to satellite cell-dependent regeneration. We studied the occurrence and myoendothelial differentiation of HPCs in muscle of patients with inflammatory myopathies. Muscle biopsies from untreated patients with dermatomyositis, polymyositis, inclusion body myositis, and controls were investigated for the expression of endothelial (CD31, von Willebrand factor, vascular endothelial growth factor receptor 2), hematopoietic (CD34, CD133, CD45), and myogenic (Pax7, MyoD) markers by immunohistochemistry and reverse-transcriptase-polymerase chain reaction.

Clinical and electrophysiological features in Charcot-Marie-Tooth disease with mutations in the NEFL gene.

Background: To date, 13 different neurofilament light-chain polypeptide gene (NEFL) mutations have been identified in 55 patients with Charcot-Marie-Tooth disease (CMT) from 16 families. NEFL mutations were found to be associated with axonal and demyelinating variants of CMT.

Objectives: To describe the clinical features of 11 patients with CMT and NEFL mutations and to explore possible genotype-phenotype correlations.