Neuromyelitis optica spectrum disorder (NMOSD) attacks lead to incremental loss of function of the optic nerves and spinal cord. The standard of care for treatment of acute attacks to mitigate damage is high dose corticosteroids and, if needed, plasma exchange. Although the inclination among clinicians is to treat relapses as soon as they start, there is no previously published evidence to conclude that earlier treatment with corticosteroids is more effective in the long term. In this study, we correlated neurological outcomes from acute NMOSD relapses with delay to treatment, as well as demographic and clinical characteristics that influence prognosis.