AQP4 and neuromyelitis optica: She fulfilled both the 2015 International Panel for NMO Diagnosis (IPND) criteria and the 2023 revised recommendations by the Neuromyelitis Optica Study Group (NEMOS), demonstrating AQP4-IgG seropositivity along with optic neuritis and corresponding T2-hyperintense lesions on optic nerve MRI (8, 15).