OVERVIEW

Expert Clinical Perspectives: Paraproteinemic neuropathies is organized by American Association of Neuromuscular & Electrodiagnostic Medicine (AANEM).

Expires on : Jun 01, 2027

Description:
The diagnostic evaluation of a peripheral neuropathy includes testing for the presence of monoclonal gammopathy, which can be found in about 10% of patients with peripheral neuropathy. Our role, as physicians, is to determine whether the neuropathy is directly related to the gammopathy or whether the co-occurrence of these two disorders is purely coincidental. The evaluating physician needs to be familiar with
the different types of neuropathies associated with monoclonal gammopathies, their clinical and electrodiagnostic characteristics, and their appropriate diagnostic evaluation and management. Testing for monoclonal protein disorders includes serum protein electrophoresis (SPEP) and immunofixation of blood, and in some cases of urine, as well as measurement of free light chains and quantitative immunoglobulins. Specific antibody testing is directed by paraprotein type and neuropathy phenotype. Patients with abnormal free light chains in association with sensory and autonomic neuropathy should be evaluated for AL amyloidosis. When a lambda monoclonal protein is identified together with a clinical phenotype of chronic inflammatory demyelinating neuropathy (CIDP), a diagnosis of polyneuropathy, organomegaly, endocrinopathy, monoclonal plasma cell disorder, skin changes (POEMS) syndrome should be considered. Patients with IgM paraprotein associated neuropathy should be assessed for distal acquired demyelinating sensorimotor (DADS) neuropathy, with or without anti myelin associated glycoprotein (MAG) antibody or CANOMAD syndrome. In many cases, a monoclonal gammopathy of uncertain significance (MGUS) is incidental and unrelated to the neuropathy. Collaboration with oncology is critical in evaluating patients with monoclonal proteins to assess for underlying plasma cell neoplasms or B cell lymphomas.

Objectives :
The objectives of this activity are to:
• Be able to order the appropriate diagnostic tests for paraproteinemias in patients with peripheral neuropathies undetermined etiology
• Understand the role of anti-MAG antibodies and vascular endothelial growth factor in the pathogenesis of paraproteinemic neuropathies, and be able to incorporate this information in an appropriate diagnostic evaluation
• Recognize and properly evaluated patients suspected of having neuropathies associated with AL amyloidosis, POEMS syndrome, DADS neuropathy, CANOMAD, and cryoglobulinemia.