Neuromyelitis optica spectrum disorder (NMOSD) – diagnosis, epidemiology, clinical course, treatment
Devic’s disease (neuromyelitis optica, NMO) was first described under this name in 1894, and it was originally thought of as a variant of multiple sclerosis. However, following the discovery of anti-aquaporin-4 antibodies (anti-Aq4-Ab), neuromyelitis optica was reported as a new nosological entity, and more insights were gained into its pathophysiology. At present, neuromyelitis optica spectrum disorder (NMOSD) is divided into seropositive and seronegative subgroups. Seropositive NMOSD is associated with the presence of anti-aquaporin-4 antibodies, and in the seronegative variant the antibodies are absent. The presence of a third variant, isolated from the seronegative form of NMOSD has also been postulated, characterised by the presence of antibodies against myelin oligodendrocyte glycoprotein (anti-MOG). In 2015, Wingerchuk et al. published updated consensus diagnostic criteria for neuromyelitis optica spectrum disorders. NMOSD is a group of inflammatory demyelinating disorders of the central nervous system characterised by spinal cord and optic nerve involvement. The most common manifestations include recurrent optic neuritis or bilateral optic neuritis, and longitudinally extensive transverse myelitis. The clinical spectrum of neuromyelitis optica also comprises less common presentations such as area postrema syndrome, acute brain stem syndrome, symptomatic narcolepsy or acute diencephalic syndrome. Identification of the new nosological entity has contributed to the verification of conventional medical management, and brought improvements in patient therapy. The paper aims to present updated diagnostic criteria and proposed therapeutic modalities for the management of exacerbations as well as maintenance treatment based on the latest clinical evidence.