Sommeil paradoxal | EPFL Graph Search

vignette|Polysomnographie. Encadré en rouge l'EEG lors du sommeil paradoxal, la barre rouge indique les mouvements oculaires. Le sommeil paradoxal, connu également comme le sommeil REM (Rapid Eye Movement), fait suite au sommeil lent (« sommeil à ondes lentes » désignant les stades 3 et 4), et constitue le cinquième et dernier stade d'un cycle du sommeil. Une « nuit » comprend de trois à six cycles successifs d'une durée chacun de 90 à 120 minutes. Chez une personne normale, la durée du sommeil paradoxal occupe environ 25 % de la durée d'une nuit, et s'accroît à chaque cycle jusqu'au réveil. C'est la phase du sommeil au cours de laquelle les rêves dont on se souvient se produisent. Il se caractérise par des mouvements oculaires rapides, d'où le nom anglais Rapid Eye Movement, une atonie musculaire, une respiration et un rythme cardiaque irréguliers, une température corporelle déréglée. On observe une dilatation des organes pelviens et une érection qui, chez le mâle, peut être suivie

Sleep: An Open-Source Python Software for Visualization, Analysis, and Staging of Sleep Data

Raphaël Vallat

We introduce Sleep, a new Python open-source graphical user interface (GUI) dedicated to visualization, scoring and analyses of sleep data. Among its most prominent features are: (1) Dynamic display of polysomnographic data, spectrogram, hypnogram and topographic maps with several customizable parameters, (2) Implementation of several automatic detection of sleep features such as spindles, K-complexes, slow waves, and rapid eye movements (REM), (3) Implementation of practical signal processing tools such as re-referencing or filtering, and (4) Display of main descriptive statistics including publication-ready tables and figures. The software package supports loading and reading raw EEG data from standard file formats such as European Data Format, in addition to a range of commercial data formats. Most importantly, Sleep is built on top of the VisPy library, which provides GPU-based fast and high-level visualization. As a result, it is capable of efficiently handling and displaying large sleep datasets. Sleep is freely available (http://visbrain. org/sleep) and comes with sample datasets and an extensive documentation. Novel functionalities will continue to be added and open-science community efforts are expected to enhance the capacities of this module.

Frontiers Research Foundation2017

Sleep-dependent consolidation of face recognition and its relationship to REM sleep duration, REM density and Stage 2 sleep spindles

Face recognition is a highly specialized capability that has implicit and explicit memory components. Studies show that learning tasks with facial components are dependent on rapid eye movement and non-rapid eye movement sleep features, including rapid eye movement sleep density and fast sleep spindles. This study aimed to investigate the relationship between sleep-dependent consolidation of memory for faces and partial rapid eye movement sleep deprivation, rapid eye movement density, and fast and slow non-rapid eye movement sleep spindles. Fourteen healthy participants spent 1night each in the laboratory. Prior to bed they completed a virtual reality task in which they interacted with computer-generated characters. Half of the participants (REMD group) underwent a partial rapid eye movement sleep deprivation protocol and half (CTL group) had a normal amount of rapid eye movement sleep. Upon awakening, they completed a face recognition task that contained a mixture of previously encountered faces from the task and new faces. Rapid eye movement density and fast and slow sleep spindles were detected using in-house software. The REMD group performed worse than the CTL group on the face recognition task; however, rapid eye movement duration and rapid eye movement density were not related to task performance. Fast and slow sleep spindles showed differential relationships to task performance, with fast spindles being positively and slow spindles negatively correlated with face recognition. The results support the notion that rapid eye movement and non-rapid eye movement sleep characteristics play complementary roles in face memory consolidation. This study also raises the possibility that fast and slow spindles contribute in opposite ways to sleep-dependent memory consolidation.

Wiley2017

REM sleep and muscle atonia in brainstem stroke: A quantitative polysomnographic and lesion analysis study

Eva Blondiaux, Lukas Heydrich

Important brainstem regions are involved in the regulation of rapid eye movement sleep. We hypothesized that brainstem stroke is associated with dysregulated rapid eye movement sleep and related muscle activity. We compared quantitative/qualitative polysomnography features of rapid eye movement sleep and muscle activity (any, phasic, tonic) between 15 patients with brainstem stroke (N = 46 rapid eye movement periods), 16 patients with lacunar/non-brainstem stroke (N = 40 rapid eye movement periods), 15 healthy controls (N = 62 rapid eye movement periods), and patients with Parkinson's disease and polysomnography-confirmed rapid eye movement sleep behaviour disorder. Further, in the brainstem group, we performed a magnetic resonance imaging-based lesion overlap analysis. The mean ratio of muscle activity to rapid eye movement sleep epoch in the brainstem group ("any" muscle activity 0.09 +/- 0.15; phasic muscle activity 0.08 +/- 0.14) was significantly lower than in the lacunar group ("any" muscle activity 0.17 +/- 0.2, p < 0.05; phasic muscle activity 0.16 +/- 0.19, p < 0.05), and also lower than in the control group ("any" muscle activity 0.15 +/- 0.17, p < 0.05). Magnetic resonance imaging-based lesion analysis indicated an area of maximum overlap in the medioventral pontine region for patients with reduced phasic muscle activity index. For all groups, mean values of muscle activity were significantly lower than in the patients with Parkinson's disease and polysomnography-confirmed REM sleep behaviour disorder group ("any" activity 0.51 +/- 0.26, p < 0.0001 for all groups; phasic muscle activity 0.42 +/- 0.21, p < 0.0001 for all groups). For the tonic muscle activity in the mentalis muscle, no significant differences were found between the groups. In the brainstem group, contrary to the lacunar and the control groups, "any" muscle activity index during rapid eye movement sleep was significantly reduced after the third rapid eye movement sleep phase. This study reports on the impact of brainstem stroke on rapid eye movement atonia features in a human cohort. Our findings highlight the important role of the human brainstem, in particular the medioventral pontine regions, in the regulation of phasic muscle activity during rapid eye movement sleep and the ultradian distribution of rapid eye movement-related muscle activity.

WILEY2022

REM sleep and muscle atonia in brainstem stroke: A quantitative polysomnographic and lesion analysis study

Eva Blondiaux, Lukas Heydrich

WILEY2022