[A case of neuromyelitis optica spectrum disorder (NMOSD) with Sjögren's syndrome manifested only brain involvement by preceding parotitis].

A 33 year-old woman presented with intentional incontinence, motor aphasia, supranuclear gaze palsy, and spasticity after parotitis. Brain magnetic resonance images (MRI) showed abnormal signaling in long corticospinal tract involving internal capsules and cerebral peduncles, middle cerebellar peduncle, and frontal subcortical white matter lesions. She had a long history of dry eye and mouth. Immunoserological study showed that she was positive for anti-SS-A, aquaporin 4 (AQP4), and AQP5 antibodies. She clinically showed not only Sjögren's syndrome but also neuromyelitis optica spectrum disorder (NMOSD) without optic neuritis or myelitis. She responded to steroid followed by plasma exchange dramatically. Thereafter, the relapse of brain lesion was once detected while tapering of steroid, but her symptoms have been stable for several years after administration of immunosuppressant. This case suggested that salivary gland inflammation might be associated with the pathogenesis of NMOSD.