Benefits of Early Versus Late Initiation of Intravenous Immunoglobulin in the Treatment of Patients With Anti-3-Hydroxy-3-Methylglutaryl-Coenzyme A Reductase Immune-Mediated Necrotizing Myopathy.

Objective: No clinical trials have been conducted to establish optimal and effective treatment in patients with immune-mediated necrotizing myopathy (IMNM), which can have a refractory course with increased morbidity from permanent muscle damage, especially in patients who experience delay in diagnosis and treatment. A subset of autoimmune necrotizing myopathy is associated with antibodies against 3-hydroxy-3-methylglutaryl-coenzyme A reductase (HMGCR). Treatment involves withdrawing statins and using a combination of immunosuppressant and immunomodulatory treatment.

Safety and clinical activity of autologous RNA chimeric antigen receptor T-cell therapy in myasthenia gravis (MG-001): a prospective, multicentre, open-label, non-randomised phase 1b/2a study.

Background: Chimeric antigen receptor (CAR) T cells are highly effective in treating haematological malignancies, but associated toxicities and the need for lymphodepletion limit their use in people with autoimmune disease. To explore the use of CAR T cells for the treatment of people with autoimmune disease, and to improve their safety, we engineered them with RNA (rCAR-T)-rather than the conventional DNA approach-to target B-cell maturation antigen (BCMA) expressed on plasma cells. To test the suitability of our approach, we used rCAR-T to treat individuals with myasthenia gravis, a prototypical autoantibody disease mediated partly by pathogenic plasma cells.

Coexisting sporadic late onset nemaline myopathy and AL amyloid myopathy - incidental or related?

Sporadic late onset nemaline myopathy (SLONM) and amyloid myopathy are frequently unrecognized acquired and treatable myopathies, which classically present with rapidly progressive and severe proximal muscle weakness. We report a case of SLONM and amyloid myopathy associated with IgM lambda monoclonal gammopathy in a 77-year-old Caucasian man. Creatine kinase (CK) was mildly elevated.

Unusual cases of Anti-SRP necrotizing myopathy with predominant distal leg weakness and atrophy.

Anti-SRP necrotizing myopathy is classically characterized by subacute or chronic, severe, progressive and symmetric myositis which predominantly affects proximal muscles. We report two unusual cases presenting with predominantly distal, asymmetric weakness, with selective involvement of the posterior compartment of the thighs, gastrocnemius, and soleus muscles, in addition to inflammation and edema on STIR or T2-weighted, fat-saturated MRI. In each case, creatine kinase (CK) levels were >10 times normal and myositis panels returned positive for anti-SRP.

CIDP mimics: a case series.

Background: To report our experience with a group of patients referred for refractory CIDP who fulfilled "definite" electrodiagnostic EFNS criteria for CIDP but were found to have an alternate diagnosis.

Methods: Patients who were seen between 2017 and 2019 for refractory CIDP that fulfilled "definite" electrodiagnostic ENFS criteria for CIDP, but had an alternate diagnosis, were included. Patients who correctly had CIDP, anti MAG neuropathy, or MMN with conduction block, were excluded from the study.

Refractory CIDP: Clinical characteristics, antibodies and response to alternative treatment.

Objective: To review the clinical characteristics, antibodies, and response to alternative treatments in a cohort of patients with refractory CIDP.

Methods: We reviewed the charts of all CIDP patients seen at the Oregon Health & Science University neuromuscular clinic between 2017 and 2019. We collected demographics, clinical characteristics, antibodies, and response to treatments.

Nusinersen in adult patients with spinal muscular atrophy: Observations from a single center.

Objective: To report our experience with adult patients with spinal muscular atrophy (SMA), some of whom were treated with nusinersen.

Methods: We reviewed charts of adult patients with SMA seen in our neuromuscular clinic between 2017 and 2019 and noted their demographics, clinical characteristics, treatment, and side effects.

Results: Twenty-two patients were included.

Diagnosis of paraproteinemic neuropathy: Room for improvement.

Objective: To report our institutional experience with paraproteinemic neuropathy.

Methods: We reviewed the charts of patients evaluated at our tertiary, academic neuromuscular clinic for neuropathy between 2017 and 2019 and selected those with a serum monoclonal protein. We collected patients' characteristics and reviewed their initial diagnoses and eventual outcomes.

Screening for genetic mutations in patients with neuropathy without definite etiology is useful.

Objective: To determine the clinical usefulness of systemic genetic testing in neuropathies without definite etiology.

Methods: We systematically performed genetic testing in all patients with neuropathy who did not have a definite etiology, seen at our neuromuscular clinic between 2017 and 2020. The testing consisted of an inherited neuropathy panel (72-81 genes), which used next-generation sequencing technology.

Selective serotonin reuptake inhibitors ameliorate MEGF10 myopathy.

MEGF10 myopathy is a rare inherited muscle disease that is named after the causative gene, MEGF10. The classic phenotype, early onset myopathy, areflexia, respiratory distress and dysphagia, is severe and immediately life-threatening. There are no disease-modifying therapies.

Bright tongue sign in patients with late-onset Pompe disease.

Background: Late-onset Pompe disease (LOPD) is an often misdiagnosed inherited myopathy for which treatment exists. We noticed a bright tongue sign on brain MRIs of two patients who were admitted to the ICU for respiratory failure of unclear origin, and who were eventually diagnosed with LOPD. This led us to systematically review brain MRIs of patients with LOPD and various other neuromuscular disorders (NMD).

Diagnostic utility of exome sequencing in the evaluation of neuromuscular disorders.

Objective: To evaluate the diagnostic yield and workflow of genome-scale sequencing in patients with neuromuscular disorders (NMDs).

Methods: We performed exome sequencing in 93 undiagnosed patients with various NMDs for whom a molecular diagnosis was not yet established. Variants on both targeted and broad diagnostic gene lists were identified.

Late-onset Becker muscular dystrophy: Refining the clinical features and electrophysiological findings.

Introduction: The aim of this study was to characterize a unique distribution of muscle involvement in sporadic Becker muscle dystrophy (BMD).

Methods: Retrospective chart review, clinical examination, electrophysiological studies, cardiac testing, and genetic testing were performed in 5 patients.

Results: Predominant weakness and atrophy of biceps brachii, hip adduction, and quadriceps muscles was noted along with calf and extensor forearm hypertrophy.

Toxoplasmic encephalitis during mycophenolate mofetil immunotherapy of neuromuscular disease.

Objective: To show that immunotherapy with medications such mycophenolate mofetil (MMF) can cause serious complications in patients with neuromuscular disorders.

Methods: Two patients with neuromuscular disorders on immunotherapy with long-term MMF who developed toxoplasmic encephalitis (TE) were included in this case series.

Results: One patient with myasthenia gravis and one patient with inflammatory myopathy on immunotherapy with long-term MMF developed severe TE.

Dermatomyositis as a presentation of neuromyelitis optica spectrum disorder.

Importance: This is the first report of neuromyelitis optica spectrum disorder (NMOSD) associated with dermatomyositis (DM).

Report: A 40year-old Caucasian female presented with 6months of worsening fatigue, rash, acute weakness worse in her lower extremities, and urinary retention. She was found to have both NMOSD and anti-melanoma differentiation-associated gene (MDA)5 positive DM with interstitial lung disease (ILD).

Pearls & Oy-sters: clues to the diagnosis of adult-onset acid maltase deficiency.

Adult-onset Pompe disease (acid maltase deficiency, glycogen storage disease type II) should be considered in the differential diagnosis in the adult patient presenting with slowly progressive selective lower extremity weakness, specifically of the hip flexors. Hip flexion weakness may be the only finding in the earliest stages of this disease. EMG findings of myotonic discharges occurring predominately in the lower extremities or paraspinal muscles, in combination with the clinical presentation, is a clue to the diagnosis of late-onset Pompe disease.

Characteristics of magnetic resonance imaging biomarkers in a natural history study of golden retriever muscular dystrophy.

The goal of this study was to assess whether magnetic resonance imaging (MRI) biomarkers can quantify disease progression in golden retriever muscular dystrophy (GRMD) via a natural history study. The proximal pelvic limbs of ten GRMD and eight normal dogs were scanned at 3, 6, and 9-12 months of age. Several MRI imaging and texture analysis biomarkers were quantified in seven muscles.