Exploration of the Reward System by Functional MRI in Narco-cataplexy Patients With and Without REM Sleep Behavior Disorder

Up to 50% of Narcolepsy-cataplexy (NC) patients suffer from REM sleep behavior disorder (RBD), a parasomnia. A strong link was found between RBD and impulse control disorders (ICD) in Parkinson disease (PD) patients. ICD are thought to be related to a dysfunction of meso-cortico-limbic pathways which belong to the so called ''reward system''. A recent study in IRMf shows that RBD is associated with impaired reward system. A strong link was found between these two disorders and therefore we believe that RBD is associated with impaired reward system in NC The main objective of this study is to evaluate differences in brain activation between NC patients with and without RBD. The investigators hypothesize that NC patients with RBD have a more severe dysfunction of the reward system (hypoactivation of the meso-cortico-limbic pathway) than patients without RBD.