Frequency of brain MRI abnormalities in neuromyelitis optica spectrum disorder at presentation: A cohort of Latin American patients

Brain magnetic resonance imaging (BMRI) lesions were classically not reported in neuromyelitis optica (NMO). However, BMRI lesions are not uncommon in NMO spectrum disorder (NMOSD) patients. To report BMRI characteristic abnormalities (location and configuration) in NMOSD patients at presentation. Medical records and BMRI characteristics of 79 patients with NMOSD (during the first documented attack) in Argentina, Brazil and Venezuela were reviewed retrospectively. BMRI abnormalities were observed in 81.02% of NMOSD patients at presentation. Forty-two patients (53.1%) showed typical-NMOSD abnormalities. We found BMRI abnormalities at presentation in the brainstem/cerebellum (n = 26; 32.9%), optic chiasm (n = 16; 20.2%), area postrema (n = 13; 16.4%), thalamus/hypothalamus (n = 11; 13.9%), corpus callosum (n = 11; 13.9%), periependymal-third ventricle (n = 9; 11.3%), corticospinal tract (n = 7; 8.8%), hemispheric white matter (n = 1; 1.2%) and nonspecific areas (n = 49; 62.03%). Asymptomatic BMRI lesions were more common. The frequency of brain MRI abnormalities did not differ between patients who were positive and negative for aquaporin 4 antibodies at presentation. Typical brain MRI abnormalities are frequent in NMOSD at disease onset. •Brain MRI abnormalities were observed in 81.02% of NMOSD patients at presentation.•Brain typical MRI abnormalities were found in 53% of NMOSD patients at disease onset.•Brain MRI abnormalities on brainstem/cerebellum were more common.•Frequency of brain MRI did not differ significantly between the seropositive and seronegative patients.