Epidemiological Study of Treatment Approaches on AQP4-IgG Positive NMOSD in Russia

This is a multicenter, retrospective-prospective, single-arm observational cohort study using secondary data collection from routine care medical records. The primary objective is to describe baseline demographic and clinical characteristics, diagnostic algorithms, and treatment approaches. Secondary objectives are to describe Expanded Disability Status Scale (EDSS) levels and dynamics, collect the rate, duration, and reasons for hospitalizations, and evaluate physician-reported relapse profiles. Approximately 100 adults will be enrolled consecutively across about 10 specialized sites. The study will sequentially include only those patients who have signed the informed consent form (ICF). Eligible patients will be enrolled consecutively at each site to minimize selection bias. Each participant will be followed for 36 months from informed consent (T0), with data collection every 6 months (T1-T6). The baseline period is defined as the time from NMOSD diagnosis until inclusion, with retrospective data abstraction; subsequent data are collected prospectively at routine visits. All data are entered into an electronic case report form (eCRF) from paper/electronic medical records. No study-specific interventions are performed; treatment is determined by usual care.