Neuromyelitis optica spectrum disorder associated with dengue virus infection.

Dengue virus infection is a disease with high incidence in some tropical and subtropical countries. A variety of neurological complications of dengue fever (DF) has been described including two cases with the phenotype of neuromyelitis optica spectrum disorder (NMOSD). However, aquaporin-4 serostatus was unknown or negative in these patients. We report two patients with NMOSD occurring in association with DF. The first patient presented with brainstem symptoms and the second one with isolated unilateral optic neuritis. Both patients tested positive for serum AQP4-antibody. This report shows that DF may trigger seropositive NMOSD.