The article presents modern diagnostic criteria for neuromyelitis optic spectrum disorders (NMOSD) in AQP4-IgG-seropositive patients with limited or atypical forms, brain, diencephalon and brainstem leasions, who have a high risk of future relapses. On the example of a clinical case, it has been shown that area postrema syndrome can occur as the only single manifestation in the onset of NMOSD, which complicates the diagnosis of NMOSD and delays timely treatment. In turn, the delayed pathogenetic therapy during the first attack of NMOSD may cause exacerbations and patients disability.