Ravulizumab for relapse prevention in AQP4-IgG-positive neuromyelitis optica spectrum disorder: a 2-year follow-up case report.

Background: Neuromyelitis optica spectrum disorder (NMOSD) is a rare autoimmune disease of the central nervous system, distinct from multiple sclerosis, characterized by severe inflammatory attacks targeting the optic nerves, spinal cord, and brainstem. Treatment has evolved from broad immunosuppressants to targeted biologics, such as complement inhibitors (ravulizumab/eculizumab), supported by strong evidence, including the CHAMPION-NMOSD trial for ravulizumab in AQP4-Ab+ve NMOSD patients. This case highlights the importance of prompt diagnosis and innovative treatment approaches in the management of NMOSD. Case presentation: A 20-year-old woman presented with acute brainstem dysfunction (dysarthria, diplopia) and a 1-month history of area postrema syndrome (APS), progressing to dysphagia and dyspnea requiring ICU admission. Diagnostic workup revealed AQP4-IgG+ NMOSD with characteristic lesions in the area postrema, pons, and cervical cord (C1-C3). The patient achieved complete clinical recovery with ravulizumab, with near-complete radiological resolution at 3 months and clinical and radiological stability through ~24 months of follow-up, highlighting the efficacy of post-acute initiation of complement inhibition in severe NMOSD. Conclusion: This case demonstrates the diagnostic and therapeutic challenges of AQP4-IgG+ NMOSD in a young patient presenting with area postrema syndrome. The patient remained clinically stable and free of new MRI activity through ~24 months of follow-up on ravulizumab.