Cyclophosphamide for End-Stage, Treatment-Refractory Quadriplegic Chronic Inflammatory Demyelinating Polyradiculoneuropathy: A Case Report

Background Chronic Inflammatory Demyelinating Polyradiculoneuropathy (CIDP) is an acquired, immune-mediated disorder characterised by progressive and/or relapsing motor and sensory dysfunction. Standard management includes intravenous immunoglobulin, corticosteroids, and plasma exchange, but guidance is limited for patients with severe, refractory disease. Case Presentation A 49-year-old man was diagnosed with CIDP following progressive sensory and motor symptoms and confirmatory electrophysiological and cerebrospinal fluid findings. Initial treatment with intravenous immunoglobulin led to transient improvement, but he subsequently developed frequent relapses despite dose escalation, repeated high-dose corticosteroids, rituximab, and multiple courses of plasma exchange. His disease course was further complicated by axonal involvement, monoclonal gammopathy of undetermined significance, and later confirmed Sjögren’s syndrome overlap. During the clinical course he experienced a catastrophic relapse in the setting of end-stage, treatment-refractory quadriplegic CIDP, with bulbar and respiratory involvement, resulting in combined respiratory, neuromuscular, and nutritional failure requiring intensive care admission, mechanical ventilation, and tracheostomy. Intravenous cyclophosphamide was initiated during this critical phase in combination with immunoglobulin therapy. Neurological deterioration stabilised, respiratory function improved, and he was successfully weaned from ventilation. On continued combined therapy, he achieved sustained clinical stability with meaningful neurological recovery. Conclusion This case illustrates the potential role of cyclophosphamide as a rescue and maintenance therapy in severe, treatment-refractory chronic inflammatory demyelinating polyradiculoneuropathy. It highlights its possible utility in aggressive disease phenotypes with systemic autoimmune overlap when standard therapies fail.