English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Sporadic late onset nemaline myopathy (SLONM) is a rare proximal myopathy with an insidious onset and slow progression. Patients present initially with a proximal limb weakness. Most commonly dyspnea, dysphagia, facial muscle weakness, and cardiomyopathy develop with disease progression. If not treated, SLONM could result in 40% mortality within the first 12 months. In approximately half of the reported cases SLONM is associated with plasma cell disorders, mostly monoclonal gammopathy of unknown significance (MGUS) and anecdotally with multiple myeloma and light chain deposition disease [1–3]. SLONM associated with a monoclonal gammopathy (SLONM+ MGUS) has an aggressive course of the disease, more severe weakness, earlier development of dysphagia and dyspnea, and overall carries an unfavourable prognosis [1, 2]. Two approaches are used to treat SLONM+MGUS: (1) immunosuppressive therapy (steroids, steroid-sparing agents, intravenous immunoglobulins (IVIG), and plasmapheresis/plasma exchange) or (2) chemotherapy followed by autologous stem cell transplantation (ASCT). Due to the rare nature of the disease, the best treatment modality is unknown. A 64-year-old male without a background history of musculoskeletal disease presented with 1 year of progressive generalized muscle weakness, difficulties with ambulating and holding his posture. He subsequently developed dysphagia and dyspnea. On exam he could walk with support only, was in a mild respiratory distress, and had marked proximal weakness in the upper and lower extremities with visible muscle atrophy. His blood work was unremarkable, except for the presence of immunoglobulin G (IgG) lambda monoclonal (M) protein of 2.7 g/L. Bone marrow biopsy showed 5% plasma cells with no light chain restriction. Further work up for an underlying HIV or malignancy was negative. He had cardiomyopathy with global systolic dysfunction (left ventricular ejection fraction decreased to 20%). Creatinine kinase level was normal. Muscle biopsy showed variable size skeletal muscle with scattered small basophilic angulated fibers associated with mild endomysial hemolysis. Some of the muscle fibers showed dense sarcoplasmic aggregates. Electron microscopy revealed skeletal muscles with extensive myofibrillar disarray and abundant cytoplasmic nemaline rods. No rod-like inclusions were found in nuclei. Diagnostic work up did not identify any hereditary causes. The patient was diagnosed with a SLONM+MGUS and subsequently started systemic chemotherapy with cyclophosphamide, bortezomib, dexamethasone. After six cycles of this regimen he underwent conditioning with high-dose melphalan (200 mg/m) followed by ASCT. Clinical improvement started 6 weeks after the initiation of chemotherapy and was more pronounced a month after the ASCT. Twelve months following the ASCT the patient was able to walk over 5 km daily, swim, and was autonomous in daily activities. Left ventricular ejection fraction improved to 55%. He has no measurable M-protein. He was last seen in a follow-up at * Rouslan Kotchetkov kotchetkovr@rvh.on.ca

Chemotherapy with stem cell transplantation is more effective than immunotherapy in sporadic late onset nemaline myopathy with monoclonal gammopathy