尿路感染症が視神経脊髄炎スペクトラム障害の再燃を偽装した症例：症例報告

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.

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. Magnetic resonance imaging 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 a return to baseline vision. Follow-up neuro-ophthalmic examination confirmed stability without new inflammatory activity.

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