Amyloid-like IgM deposition neuropathy with multiple mononeuropathies and generalized neuropathy
Issued Date
2023-05-01
Resource Type
ISSN
09608966
eISSN
18732364
Scopus ID
2-s2.0-85151536737
Journal Title
Neuromuscular Disorders
Volume
33
Issue
5
Start Page
391
End Page
395
Rights Holder(s)
SCOPUS
Bibliographic Citation
Neuromuscular Disorders Vol.33 No.5 (2023) , 391-395
Suggested Citation
Soontrapa P. Amyloid-like IgM deposition neuropathy with multiple mononeuropathies and generalized neuropathy. Neuromuscular Disorders Vol.33 No.5 (2023) , 391-395. 395. doi:10.1016/j.nmd.2023.02.012 Retrieved from: https://repository.li.mahidol.ac.th/handle/20.500.14594/81403
Title
Amyloid-like IgM deposition neuropathy with multiple mononeuropathies and generalized neuropathy
Author(s)
Author's Affiliation
Other Contributor(s)
Abstract
Amyloid-like IgM deposition neuropathy is a distinct entity in the setting of IgM monoclonal gammopathy in which endoneurial perivascular entire IgM-particle accumulation leads to a painful sensory followed by motor peripheral neuropathy. We report a 77-year-old man presenting with progressive multiple mononeuropathies starting with painless right foot drop. Electrodiagnostic studies showed severe axonal sensory-motor neuropathy superimposed by multiple mononeuropathies. Laboratory investigations were remarkable for biclonal gammopathy of IgM kappa, IgA lambda and severe sudomotor and mild cardiovagal autonomic dysfunction. A right sural nerve biopsy showed multifocal axonal neuropathy, prominent microvasculitis, and prominent large endoneurial deposits of Congo-red negative amorphous material. Laser dissected mass spectrometry-based proteomics identified IgM kappa deposit without serum amyloid-P protein. This case has several distinctive features, including motor preceding sensory involvement, prominent IgM-kappa proteinaceous deposits replacing most of the endoneurium, a prominent inflammatory component, and improvement of motor strength after immunotherapy.