Supplementary Material for: Urinary Tract Infection Masquerading as an Neuromyelitis Optica Spectrum Disorder Exacerbation: A Case Report

Introduction: Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune demyelinating disease, characterized by severe attacks of optic neuritis and transverse myelitis. Distinguishing true relapses from infection-related pseudo-exacerbations is essential, particularly in immunosuppressed patients where clinical presentations may be atypical.

Case Presentation: An 83-year-old woman with AQP4-IgG–positive NMOSD and Parkinson’s disease presented with acute visual loss and altered mental status, initially suspected to represent a relapse. Empirical intravenous corticosteroids were administered, but her condition worsened with new hallucinations. MRI revealed no new demyelinating lesions. Urinalysis and culture confirmed a urinary tract infection due to Klebsiella oxytoca. Corticosteroids were discontinued and antibiotic therapy initiated, leading to resolution of mental status changes and return to baseline vision. Follow-up neuro-ophthalmic examination confirmed stability without new inflammatory activity.

Conclusion: Urinary tract infection can masquerade as an NMOSD exacerbation, complicating diagnosis in elderly immunosuppressed patients.