Is there a prodrome to NMOSD? An investigation of neurologic symptoms preceding the first NMOSD attack

Abstract

Background: It is unknown whether people with aquaporin-4 antibody positive (AQP4-IgG+) neuromyelitis optica spectrum disorder (NMOSD) experience a prodrome, although a few cases report AQP4 + serology up to 16 years before the first attack. Objectives: To evaluate whether individuals with AQP4-IgG + NMOSD have prodromal neurologic symptoms preceding the first attack. Methods: We reviewed medical records of participants meeting the 2015 diagnostic criteria for AQP4-IgG + NMOSD from four demyelinating disease centres in the Canadian NMOSD cohort study CANOPTICS. We searched for neurologic symptoms occurring at least 30 days before the first attack. Results: Of 116 participants with NMOSD, 17 (14.7%) had prodromal neurologic symptoms. The median age was 48 years (range 25–83) at first attack; 16 (94.1%) were female. Participants presented with numbness/tingling ( n = 9), neuropathic pain ( n = 5), visual disturbance ( n = 4), tonic spasms ( n = 2), Lhermitte sign ( n = 2), severe headache ( n = 2), incoordination ( n = 2), weakness ( n = 1), psychosis ( n = 1) or seizure ( n = 1). Of eight who underwent magnetic resonance imaging (MRI) brain, orbits and/or spinal cord, five had T2 lesions. Within 1.5–245 months (median 14) from the onset of prodromal neurologic symptoms, participants experienced their first NMOSD attack. Conclusions: One in seven people with NMOSD experienced neurologic symptoms before their first attack. Further investigation of a possible NMOSD prodrome is warranted.