Frequency of area postrema syndrome in a Peruvian cohort of patients with neuromyelitis optica spectrum disorder

Background: Neuromyelitis Optica Spectrum Disorder (NMOSD) is an autoimmune, inflammatory disorder of the Central Nervous System that typically involves the spinal cord, optic nerves, and area postrema. Descriptions of area postrema syndrome (APS) in Latin America are scarce; for this reason, we aimed to assess the frequency and clinical characteristics of APS in a NMOSD cohort from a tertiary-level neurological center in Lima-Peru. Methods: This is a descriptive and retrospective study. We reviewed medical reports of 82 patients with NMOSD, and we found that 30 patients met the study criteria. Results: 30 (36.6%) out of 82 patients presented APS at onset (19 patients) or during the course of the diseases (11 patients), most of our patients were women. The average age of onset was 43.5 years, the number of relapses was statistically greater in those who had APS during follow-up, and acute myelitis was the most frequent subsequent relapse, followed by optic neuritis in both groups at disease onset and during follow-up. Age, sex, and AQP4-Ab positivity did not appear to be associated with APS severity. Conclusions: A high proportion of APS was shown in a Peruvian NMOSD cohort, and most of the cases were severe and female. Our low sample size does not allow us to detect risk factors.