Image For Activity Cover
Journal Review: Neuromuscular amyloidosis: Unmasking the master of disguise
Journal Review: Neuromuscular amyloidosis: Unmasking the master of disguise

Amyloidosis refers to an etiologically heterogeneous group of protein misfolding diseases, pathologically characterized by extracellular amyloid fibrils producing congophillic amorphous deposits in organs and tissues, which may lead to severe organ dysfunction and mortality. Clinical presentations vary and are often nonspecific, depending on what organs or tissues are affected. In systemic amyloidosis, the peripheral nervous system is commonly affected, whereas the skeletal muscles are only rarely involved. Immunoglobulin light chain (AL) amyloidosis and hereditary transthyretin (ATTRv) amyloidosis are the most frequent types of systemic amyloidosis involving the neuromuscular system. Localized amyloidosis can occur in skeletal muscle, so-called isolated amyloid myopathy. Amyloid neuropathy typically involves small myelinated and unmyelinated sensory and autonomic nerve fibers early in the course of the disease, followed by large myelinated fiber sensory and motor deficits. The relentlessly progressive nature with motor, painful sensory and severe autonomic dysfunction, profound weight loss, and systemic features are distinct characteristics of amyloid neuropathy. Amyloid myopathy presentation differs between systemic amyloidosis and isolated amyloid myopathy. Long-standing symptoms, distal predominant myopathy, markedly elevated creatine kinase level, and lack of peripheral neuropathy or systemic features are highly suggestive of isolated amyloid myopathy. In ATTR and AL amyloidosis, early treatment correlates with favorable outcomes. Therefore, awareness of these disorders and active screening for amyloidosis in patients with neuropathy or myopathy are crucial in detecting these patients in the everyday practice of neuromuscular medicine. Herein, we review the clinical manifestations of neuromuscular amyloidosis and provide a diagnostic approach to this disorder.

The AANEM is accredited by the Accreditation Council for Continuing Medical Education (ACCME) to provide continuing medical education for physicians.

The AANEM designates this enduring material for a maximum of 1 AMA PRA Category 1 Credits TM.  Physicians should claim only the credit commensurate with the extent of their participation in the activity. Credit expires 7/17/2024.

No one involved in the planning of this CME activity had any relevant financial relationships to disclose. Any conflicts have been resolved by the Journal in accordance with the Muscle & Nerve editorial process.


Authors: Marcus V. Pinto MD, MS, P. James B. Dyck MD, Teerin Liewluck MD 

The objectives of this activity are to: 1) Be able to recognize the symptoms and signs of possible amyloidosis affecting the peripheral nervous system and order appropriate diagnostic testing; 2) Be able to recognize the symptoms and signs of possible amyloidosis affecting skeletal muscle and order appropriate diagnostic testing; 3) Become familiar with and be able to order appropriate testing for the various types of amyloidosis producing neuromuscular disorders.

Authors: Marcus V. Pinto MD, MS, P. James B. Dyck MD, Teerin Liewluck MD
Availability: On-Demand
Expires on Jul 17, 2024
Cost: Member: $0.00
Non-Member: $25.00
Credit Offered:
1 CME Credit
2621 Superior Drive NW Rochester, MN 55901
Phone: 507.288.0100
Fax: 507.288.1225
Powered By