Sleep perception in narcolepsy and hypersomnia

Background: Sleep is usually associated with a loss of consciousness of the self and the environment, but there is a lot of evidence that subjective experiences persist during sleep. Sleep perception and dreams are part of these experiences, even though they can usually only be investigated upon awakening (perception of having slept, dream memory). Sleep is an heterogeneous, unstable state and the transitions between vigilance states are progressive. These microstructural characteristics of sleep could be involved in the variability of sleep-related subjective experiences reports, as well as in the frequent discrepancy between "objective" sleep (as recorded on a polysomnography and scored by 30 s epochs according to the AASM criteria) and "subjective" sleep as perceived by the sleeper. Indeed, the "misperception" of sleep (=the fact of not perceiving that one has slept) is a frequent phenomenon in healthy subjects and in sleep disorders, whose underlying brain mechanisms remain poorly understood. This issue is particularly important to address in the context of hypersomnolence, as poor sleep perception is likely to result in increased accidental risk. The main objective of this study is to determine which macro- and micro-structural EEG markers are associated with the perception of having slept and dreamt during multiple sleep latency tests performed in patients with narcolepsy type 1, type 2, idiopathic hypersomnia and in controls. Study design: retrospective study (RNIPH) Methods: Clinical data of the patients (25/group) recorded in the Center for Sleep Medicine of the CHU of Lyon will be collected. Different markers of macro- and microstructure of sleep including microstates (microarousals during sleep and microsleeps during wake) and spectral analysis will be analyzed and correlated with the perception of sleep and dreams. Role of the trainee: participation to REB procedure, data collection in medical files, sleep recordings analysis, statistical analysis, bibliography. Localisation: CHU of Lyon and Lyon Neuroscience Research Center