In this study we investigate whether patients with neuromyelitis optica spectrum disorder (NMOSD) experience symptoms in the years before the first NMOSD attack. This is a relevant and timely investigation given evidence of prodromal phases across various neurologic diseases, including MS, although the prodrome has not been previously investigated in NMOSD. Moreover, recent research supports the existence of subclinical and atypical disease activity in NMOSD. These findings may inform efforts to further expand the clinical spectrum of NMOSD and to understand the pathogenesis of NMOSD.