Polyneuropathies and chronic inflammatory demyelinating polyradiculoneuropathy in multiple sclerosis

Abstract Background Polyneuropathies co-occurring with multiple sclerosis (MS) may be underdiagnosed while causing additional disability burden. Objective To determine polyneuropathy presence and type in MS and compare MS with chronic inflammatory demyelinating polyradiculoneuropathy (MS-CIDP) versus MS with other non-inflammatory polyneuropathies. Methods Retrospective chart review of Mayo Clinic cases diagnosed with MS and polyneuropathy. Serum from MS-CIDP for pan-IgG autoantibodies to neurofascin-155 were tested when available. Results From 1980–2013, 133 co-existing MS/ polyneuropathy cases were identified. Twenty-eight MS patients had inflammatory neuropathy (11 CIDP, 5 plexopathy, 2 vasculitis, 4 monoclonal gammopathy-associated, 6 other), 15 inherited neuropathy (8 axonal, 7 demyelinating), 32 diabetic sensorimotor polyneuropathy, and 58 other. 109 had neuropathy beginning simultaneous to or after MS diagnosis (82%). Compared to MS cases with other polyneuropathy subtypes, MS-CIDP cases had absent or reduced ankle reflexes (100 vs. 70%, p  = 0.04), earlier age of neuropathy recognition (52 vs. 58 years, p  = 0.048), worse impairment (NIS 27 vs. 22 points, p p Conclusion (1) Polyneuropathies occurring in MS contribute to neurological disability. (2) Diagnosing polyneuropathies in people with MS is challenging and, likely, under-diagnosed. Recognition is important as some polyneuropathies (e.g., CIDP) are treatable. (3) The probable over-representation of inflammatory neuropathy (especially CIDP) in MS suggests a shared dysimmune pathogenesis, supported by autoantibodies to neurofascin-155.