Refractory Morvan syndrome responsive to rituximab: a case report and review of the literature.

Morvan Syndrome (MoS) is an autoimmune disorder characterized by peripheral nerve hyperexcitability, autonomic dysfunction, and encephalopathy. We describe the case of a man with a history of thymoma diagnosed with a paraneoplastic MoS with a severe painful neuropathy refractory to immunoglobulins and steroids who had a dramatic and lasting response following treatment with rituximab. We also reviewed the clinical features, comorbidities, laboratory findings, treatment responses, relapses, and long-term outcomes of all published cases of MoS treated with rituximab. This drug appears promising for the treatment of patients with MoS who failed first line therapy with immunoglobulins and steroids.