Neuromyelitis optica spectrum disorder (NMOSD) is an uncommon antibody-mediated disease of the central nervous system. It’s characterized by severe demyelination and axonal damage predominantly targeting optic nerves and spinal cord. The reported incidence and prevalence of NMOSD are dependent on geographical location and ethnicity. There are only case reports of the disease in Peru, but no study reported epidemiological or clinical data.
We aim to describe the principal clinical characteristics of Peruvian patients with positive (P-NMOSD) and other (O-NMOSD) aquaporin-4 antibody serostatus (negative, N-NMOSD, or unknown, U-NMOSD) at disease onset.
We retrospectively reviewed medical records and applied 2015 NMOSD diagnostic criteria to all NMOSD patients who were diagnosed at the Instituto Nacional de Ciencias Neurológicas between 2013 and 2018. Mean and percentages were used to describe the variables. Data between groups were compared by Fisher’s exact test and Mann-Whitney U test for categorical and continuous data, respectively.
We included 23 P-NMOSD, 35 O-NMOSD patients (14 N-NMOSD and 21 U-NMOSD). Mean age at onset was 46.78 years (P-NMOSD 53.35 and O-NMOSD 42.46, p=0.0135). No differences in sex, number of relapses, time to diagnosis and initial syndromes were observed between groups. Regarding the presence of core clinical characteristics, we found differences in the presence of acute myelitis and symptomatic cerebral syndrome. When the spinal cord was affected, differences between groups were found regarding longitudinal extensive transverse myelitis and dorsal spinal cord involvement. Simultaneous optic neuritis and acute myelitis was the first presentation in 4% of P-NMOSD and 20% of O-NMOSD patients (p=0.094).
We described the first cohort of Peruvian NMOSD patients. Clinical characteristics were similar to other studies. P-NMOSD patients were older than O-NMOSD. O-NMOSD had more involvement of spinal cord compared with P-NMOSD with dorsal spinal cord involvement and presence of longitudinal extensive transverse myelitis.