Pseudovascular Revelation of Seropositive Neuromyelitis Optica Spectrum Disorder: A Case Report

Symptom onset in Neuromyelitis Optica spectrum disorder (NMOSD) is often acute, while sudden onset is rare and suggests vascular causes. We report the case of a 63-year-old woman who had two sudden attacks, blindness in the left eye and weakness of the lower limbs. The presence of a diencephalic hypersignal around the third ventricle and a bright spotty lesion on the MRI had evoked the NMOSD diagnosis which was confirmed by positive anti-aquaporin 4 antibodies in the serum. The patient was treated with cyclophosphamide with no relapses after 6 months of treatment. Few case reports have been published on this subject, testifying to the rarity of this "pseudo-vascular" mode of revelation of NMOSD, which may be a source of diagnostic error or delay.