Neuromyelitis optica spectrum disorder with ultra-longitudinally extensive transverse myelitis: A case report and literature review

Background: Neuromyelitis optica spectrum disorders (NMOSD) is characterized by inflammatory demyelinating events in the central nervous system (CNS), primarily affecting the spinal cord and optic nerve, with a significant influence of astrocytes. Longitudinal extensive transverse myelitis (LETM) is a distinct and relatively rare spinal cord syndrome, commonly associated with NMOSD. Case presentation: This report describes a unique case of myelitis in a patient diagnosed with NMOSD. The patient exhibited an uncommon manifestation of ultra- LETM (u-LETM), coexisting with connective tissue disorders including Sjögren's syndrome and autoimmune hepatitis-primary cholestatic cirrhosis. In the acute phase, high-dose methylprednisolone pulse therapy was administered in combination with intravenous human immunoglobulin, while prednisone was gradually tapered and discontinued upon stabilization of the patient's condition. Simultaneously, sequential disease-modifying therapy was initiated, starting with long-term oral administration of mycophenolate mofetil, followed by cyclophosphamide, telitacicept, and Inebilizumab. During follow-up visits conducted every three months, the patient showed gradual improvement, eventually achieving the ability to stand and walk independently. Conclusions: Early and comprehensive evaluation of autoimmune diseases is crucial in patients with NMOSD presenting with u-LETM as the initial symptom. Prompt treatment initiation, followed by disease-modifying therapy, is essential for improving patient prognosis.