Investigation of health care use and a possible prodrome before the first attack in NMOSD and MOGAD

Prodromal phases are well recognized in many inflammatory and neurodegenerative diseases, including multiple sclerosis. We evaluated the possibility of a prodrome in aquaporin-4 antibody positive (AQP4+) neuromyelitis optica spectrum disorder (NMOSD) and myelin oligodendrocyte glycoprotein antibody disease (MOGAD) using health administrative data.