Clinical and neurophysiological description of patients with POEMS syndrome

Introduction: POEMS syndrome (polyneuropathy, organomegaly, endocrinopathy, monoclonal protein, skin changes) is a monoclonal gammopathy with polyneuropathy as a mandatory criterion. Objective: To describe potential associations between clinical expression and electrodiagnostic patterns in POEMS syndrome. Method: Observational, retrospective, and cross-sectional study of cases cared in a referral center diagnosed with POEMS syndrome from 2009-2019. Results: Eleven cases (8 men) were analyzed. Median age at diagnosis was 40 years (range: 31-51, mean: 37.19 +/- 15.67 years). Mean latency at diagnosis was 9.7 +/- 8.37 months. In all subjects, initial clinical manifestation was polyneuropathy. Most patients had an axonal pattern (n = 5), followed by demyelinating (n = 4), and mixed (n = 2). Monoclonal gammopathy was observed in all patients (6 lambda, and 5 kappa cases, immunoglobulin [Ig] G: 72%, IgA: 18%, IgM: 9%). Medical Research Council sum score was lower in the axonal pattern (median: 37.00, vs. 45.5, p = 0.024). There were no differences in the systemic involvement between electrophysiological patterns. Conclusion: Electrophysiological patterns are unlikely to have a clear extra-neurological clinical correspondence; however this will need to be definitively proven with a larger sample size.