Rapid eye movement sleep behaviour disorder in patients with narcolepsy is associated with hypocretin-1 deficiency
Open Access
- 1 February 2010
- journal article
- research article
- Published by Oxford University Press (OUP) in Brain
- Vol. 133 (2), 568-579
- https://doi.org/10.1093/brain/awp320
Abstract
Rapid eye movement sleep behaviour disorder is characterized by dream-enacting behaviour and impaired motor inhibition during rapid eye movement sleep. Rapid eye movement sleep behaviour disorder is commonly associated with neurodegenerative disorders, but also reported in narcolepsy with cataplexy. Most narcolepsy with cataplexy patients lack the sleep–wake, and rapid eye movement sleep, motor-regulating hypocretin neurons in the lateral hypothalamus. In contrast, rapid eye movement sleep behaviour disorder and hypocretin deficiency are rare in narcolepsy without cataplexy. We hypothesized that rapid eye movement sleep behaviour disorder coexists with cataplexy in narcolepsy due to hypocretin deficiency. In our study, rapid eye movement sleep behaviour disorder was diagnosed by the International Classification of Sleep Disorders (2nd edition) criteria in 63 narcolepsy patients with or without cataplexy. Main outcome measures were: rapid eye movement sleep behaviour disorder symptoms; short and long muscle activations per hour rapid eye movement and non-rapid eye movement sleep; and periodic and non-periodic limb movements per hour rapid eye movement and non-rapid eye movement sleep. Outcome variables were analysed in relation to cataplexy and hypocretin deficiency with uni- and multivariate logistic/linear regression models, controlling for possible rapid eye movement sleep behaviour disorder biasing factors (age, gender, disease duration, previous anti-cataplexy medication). Only hypocretin deficiency independently predicted rapid eye movement sleep behaviour disorder symptoms (relative risk = 3.69, P = 0.03), long muscle activations per hour rapid eye movement sleep (ln-coefficient = 0.81, P < 0.01), and short muscle activations per hour rapid eye movement sleep (ln-coefficient = 1.01, P < 0.01). Likewise, periodic limb movements per hour rapid eye movement and non-rapid eye movement sleep were only associated with hypocretin deficiency (P < 0.01). A significant association between hypocretin deficiency and cataplexy was confirmed (P < 0.01). In a sub-analysis, hypocretin deficiency suggested the association of periodic limb movements and rapid eye movement sleep behaviour disorder outcomes (symptoms, non-periodic short and long muscle activity) in rapid eye movement sleep. Our results support the hypothesis that hypocretin deficiency is independently associated with rapid eye movement sleep behaviour disorder in narcolepsy. Thus, hypocretin deficiency is linked to the two major disturbances of rapid eye movement sleep motor regulation in narcolepsy: rapid eye movement sleep behaviour disorder and cataplexy. Hypocretin deficiency is also significantly associated with periodic limb movements in rapid eye movement and non-rapid eye movement sleep, and provides a possible pathophysiological link between rapid eye movement sleep behaviour disorder and periodic limb movements in narcolepsy. The study supports the hypothesis that an impaired hypocretin system causes a general instability of motor regulation during wakefulness, rapid eye movement and non-rapid eye movement sleep in human narcolepsy.Keywords
This publication has 36 references indexed in Scilit:
- CSF hypocretin-1 assessment in sleep and neurological disordersThe Lancet Neurology, 2008
- Characterization of GABAergic neurons in rapid‐eye‐movement sleep controlling regions of the brainstem reticular formation in GAD67–green fluorescent protein knock‐in miceEuropean Journal of Neuroscience, 2008
- Periodic leg movements during sleep and wakefulness in narcolepsyJournal of Sleep Research, 2007
- REM Sleep Characteristics in Narcolepsy and REM Sleep Behavior DisorderSleep, 2007
- Pathophysiology of REM sleep behaviour disorder and relevance to neurodegenerative diseaseBrain, 2007
- Hypocretins (orexins) and sleep–wake disordersThe Lancet Neurology, 2005
- Increased Muscle Activity During Rapid Eye Movement Sleep Correlates with Decrease of Striatal Presynaptic Dopamine Transporters. IPT and IBZM SPECT Imaging in Subclinical and Clinically Manifest Idiopathic REM Sleep Behavior Disorder, Parkinson's Disease, and ControlsSleep, 2003
- Alteration of the striatal dopaminergic system in human narcolepsyNeurology, 2003
- Neuroimmunoregulation of Androgens in the Adrenal Gland and the SkinHormone Research in Paediatrics, 2000
- Effects of bromocriptine on periodic limb movements in human narcolepsyNeurology, 1993