European Federation of Neurological Societies/Peripheral Nerve Society Guideline on management of paraproteinemic demyelinating neuropathies. Report of a joint task force of the European Federation of Neurological Societies and the Peripheral Nerve Society

Abstract Background: Paraprotein‐associated neuropathies have heterogeneous clinical, neurophysiological, neuropathological, and hematological features. Objectives: The aim of this guideline was to prepare evidence‐based and consensus guidelines on the clinical management of patients with both a demyelinating neuropathy and a paraprotein paraproteinemic demyelinating neuropathy (PDN)]. Methods: Disease experts and a representative of patients considered references retrieved from MEDLINE and the Cochrane Library and prepared statements that were agreed in an iterative fashion. Recommendations: In the absence of adequate data, evidence‐based recommendations were not possible, but the Task Force agreed on the following good practice points: (1) patients with PDN should be investigated for a malignant plasma cell dyscrasia; (2) the paraprotein is more likely to be causing the neuropathy if the paraprotein is immunoglobulin M (IgM), antibodies are present in serum or on biopsy, or the clinical phenotype is chronic distal sensory neuropathy; (3) patients with IgM PDN usually have predominantly distal and sensory impairment, with prolonged distal motor latencies, and often anti‐myelin‐associated glycoprotein antibodies; (4) IgM PDN sometimes responds to immunotherapies. Their potential benefit should be balanced against their possible side effects and the usually slow disease progression; (5) IgG and IgA PDN may be indistinguishable from chronic inflammatory demyelinating polyradiculoneuropathy clinically, electrophysiologically, and in response to treatment; and (6) for POEMS syndrome, local irradiation or resection of an isolated plasmacytoma, or melphalan with or without corticosteroids, should be considered, with hemato‐oncology advice.