Abstract
Around a third of a human lifespan is spent in the essential life process of sleep. Disordered sleep is present in 15-35% of adults and is frequently underrecognized and underreported. Sleep disorders are associated with an elevated risk of hypertension, diabetes, obesity, depression, heart attack and stroke. The burden to health care associated with sleep disorders is significant and likely underestimated. Neuromyelitis optica spectrum disorder (NMOSD) is a relapsing autoimmune disorder of the central nervous system characterised by devastating relapses which can result in blindness, disability, and death. Symptomatic narcolepsy is a core feature of the disease and though sleep disruption is common, it has not been systemically studied in large NMOSD cohorts. We present a literature review concerning sleep and circadian rhythm in NMOSD and offer a conceptual model of possible underlying pathophysiological mechanisms with suggestions for future research.