A Rare Case of Neuromyelitis Optica Spectrum Disorder Secondary to Primary Sjögren's Syndrome in an Older Woman.

Primary Sjögren's syndrome is an autoimmune disorder that is characterized by lymphocytic infiltration of salivary and lacrimal glands. The extra-glandular manifestations might be arthritis, myalgia, glomerulonephritis, skin rashes, and neurologic involvement. One of the uncommon neurologic manifestations is neuromyelitis optica spectrum disorder (NMOSD). In the present case, an older woman is reported that was diagnosed with NMOSD secondary to keratoconjunctivitis sicca, which is rare in geriatric practice.