Okoneshnikova Epidemiological characteristics of Neuromyelitis Optica Spectrum Disorder worldwide and in the Republic of Sakha (Yakutia)

Abstract

Over the past decade, a significant increase in the prevalence and incidence of neuromyelitis optica spectrum disorder (NMOSD) has been observed worldwide, including in the Russian population, as exemplified by the Sakha Republic (Yakutia). These changes are particularly pronounced when analyzing the Yakut ethnic group, which constitutes the overwhelming majority of the republic’s population. Neuromyelitis optica spectrum disorder manifests as isolated or combined involvement of unilateral or bilateral optic neuritis, longitudinally extensive transverse myelitis, and signs of brainstem and other brain region involvement, most commonly following a relapsing course. The disorder exhibits distinct gender and age characteristics, with a marked female predominance and onset typically occurring in young adulthood during the prime working years. NMOSD is highly disabling, and each relapse carries a high risk of permanent disability, which has substantial socio-economic implications.