Dissociated rapid eye movement sleep dream experiences in type 1 narcolepsy: a case report

Abstract

Clinical and polygraphic hallmarks of type 1 narcolepsy (NT1) are the occurrence of episodes of rapid eye movement (REM) sleep at the onset of nocturnal or daytime sleep (SOREMP) and dissociated wake–REM sleep manifestations (cataplexy, sleep paralysis, hallucinations) [1]. Some recent neurophysiological findings, demonstrating that SOREMP in NT1 lacks the typical sympathetic activation of REM sleep [2], support that SOREMP per se may also be an REM sleep–wakefulness dissociation in NT1. Moreover, several behavioral and cognitive phenomena may surface during SOREMPs: REM sleep behavior disorder (RBD), characterized by loss of REM sleep muscle atonia coupled with dream-enacting behaviors [3]; cataplexy (episodes of suddenmuscular weakness triggered by emotions) [4]; dream lucidity (maintenance of reality testing and volitional control of thinking while dreaming) [5,6]; hallucinatory phenomena such as flying sensation [7]; and out-of-body experiences (OBE; metamorphosis or exit of the self from the body) [8]. We report here an NT1 patient showing the co-occurrence of several dissociatedmental andmotor features of REM sleep during the same daytime SOREMPs. 2. Case description