Sleep and temperature rhythms in two sisters with P102L Gerstmann-Sträussler-Scheinker (GSS) disease

BackgroundSleep disorders are increasingly recognized in the symptomatology of many neurodegenerative diseases. Gerstmann-Sträussler-Scheinker (GSS) disease is a hereditary prion disease featuring cerebellar ataxia, akinetic parkinsonism, pyramidal signs and cognitive decline.MethodsWe performed a polysomnographic study (PSG) of sleep and body core temperature (BcT°) in two sisters with GSS.ResultsOur study showed protracted nocturnal awakenings, reduced sleep efficiency and brief daytime naps but also qualitatively preserved slow-wave and REM sleep and substantially normal arousal and periodic limb movements in sleep indices and BcT° rhythm.ConclusionsThese findings conflict with those in multiple system atrophy and other prion diseases such as fatal familial insomnia, which enter the differential diagnosis of GSS and are characterized by prominently disrupted sleep-wake and BcT° cycles.