Martín-Nares E, et al. - Individuals with diagnosis of neuromyelitis optica spectrum disorder (NMOSD) and a concomitant diagnosis of SLE or primary Sjögren's syndrome (pSS) were included (n = 12; SLE = 7, pSS = 5) in order to explain the clinical and radiological features and outcomes of individuals with aquaporin-4-immunoglobulin G (AQP4-IgG) seropositive NMOSD coexisting with SLE and pSS in a single center. In five individuals NMOSD proceeded SLE/pSS onset, four cases had a concurrent presentation, and in three NMOSD followed pSS onset. Acute transverse myelitis/longitudinally extensive transverse myelitis, optic neuritis, a cerebral syndrome, and each area postrema syndrome, acute brainstem syndrome and cerebellar syndrome were encountered by 11, five, three, and two, respectively. At median follow-up of 89.5 months, 11 patients went into either total or partial NMOSD remission. Hence, AQP4-IgG seropositive NMOSD emerged in the context of quiescent SLE and pSS with extraglandular characteristics. Furthermore, collaborative multicenter studies are required to refine the natural history and outcomes of this overlap syndrome since NMOSD coexisting with SLE/pSS is infrequent.