Treatment-responsive glycogen storage myopathy in a patient with POEMS syndrome: A new monoclonal gammopathy-associated myopathy
Issued Date
2023-01-01
Resource Type
ISSN
13515101
eISSN
14681331
Scopus ID
2-s2.0-85167728831
Pubmed ID
37522432
Journal Title
European Journal of Neurology
Rights Holder(s)
SCOPUS
Bibliographic Citation
European Journal of Neurology (2023)
Suggested Citation
Soontrapa P. Treatment-responsive glycogen storage myopathy in a patient with POEMS syndrome: A new monoclonal gammopathy-associated myopathy. European Journal of Neurology (2023). doi:10.1111/ene.16008 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/88376
Title
Treatment-responsive glycogen storage myopathy in a patient with POEMS syndrome: A new monoclonal gammopathy-associated myopathy
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
Background: Myopathies associated with monoclonal gammopathy are relatively uncommon and underrecognized, treatable myopathies, and include sporadic late onset nemaline myopathy, light chain amyloid myopathy, and a recently described vacuolar myopathy with monoclonal gammopathy and stiffness (VAMGS). Herein, we report a new subtype of monoclonal gammopathy-associated myopathy (MGAM) in a polyneuropathy, organomegaly, endocrinopathy, M protein, and skin changes (POEMS) patient. Method: Case report. Results: A 51-year-old woman presented with a 6-month history of progressive bilateral foot drop, lower limb edema, and a 15-lb weight loss. She denied muscle stiffness. Neurologic exam showed severe distal weakness, mild proximal weakness, and length-dependent sensory deficits. Laboratory studies revealed biclonal gammopathy (IgG kappa and IgA lambda), thrombocytosis, and elevated vascular endothelial growth factor. Creatine kinase was normal. Electrodiagnostic studies identified mixed demyelinating and axonal polyradiculoneuropathy and a superimposed proximal myopathy. Gluteus medius biopsy demonstrated scattered fibers with glycogen-filled vacuoles, similar to VAMGS, with additional rare myofibers containing polyglucosan bodies. She was diagnosed with POEMS syndrome and concomitant glycogen storage myopathy. Next-generation sequencing of glycogen storage and polyglucosan body myopathy-related genes was unrevealing. Proximal weakness resolved after autologous stem cell transplant. Conclusions: This patient expands a spectrum of MGAM. Recognition of this condition and other subtypes of MGAM is of utmost important because they are treatable.