IFNA2 and essential thrombocythemia: <h4>Background and objectives</h4>To describe a new case of neuromyelitis optica spectrum disorder (NMOSD) induced by the administration of interferon-alpha (IFNα) and to raise awareness of this rare drug-induced disease of IFNα treatment.<h4>Methods</h4>A single case study and comprehensive literature review of eight cases.<h4>Results</h4>A 24-year-old man was diagnosed with cerebral venous thrombosis and essential thrombocythemia.