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Study Objectives The development of ambulatory technologies capable of monitoring brain activity during sleep longitudinally is critical for advancing sleep science. The aim of this study was to assess the signal acquisition and the performance of the automatic sleep staging algorithms of a reduced-montage dry-electroencephalographic (EEG) device (Dreem headband, DH) compared to the gold-standard polysomnography (PSG) scored by five sleep experts. Methods A total of 25 subjects who completed an overnight sleep study at a sleep center while wearing both a PSG and the DH simultaneously have been included in the analysis. We assessed (1) similarity of measured EEG brain waves between the DH and the PSG; (2) the heart rate, breathing frequency, and respiration rate variability (RRV) agreement between the DH and the PSG; and (3) the performance of the DH’s automatic sleep staging according to American Academy of Sleep Medicine guidelines versus PSG sleep experts manual scoring. Results The mean percentage error between the EEG signals acquired by the DH and those from the PSG for the monitoring of α was 15 ± 3.5%, 16 ± 4.3% for β, 16 ± 6.1% for λ, and 10 ± 1.4% for θ frequencies during sleep. The mean absolute error for heart rate, breathing frequency, and RRV was 1.2 ± 0.5 bpm, 0.3 ± 0.2 cpm, and 3.2 ± 0.6%, respectively. Automatic sleep staging reached an overall accuracy of 83.5 ± 6.4% (F1 score: 83.8 ± 6.3) for the DH to be compared with an average of 86.4 ± 8.0% (F1 score: 86.3 ± 7.4) for the 5 sleep experts. Conclusions These results demonstrate the capacity of the DH to both monitor sleep-related physiological signals and process them accurately into sleep stages. This device paves the way for, large-scale, longitudinal sleep studies. Clinical Trial Registration NCT03725943.

In recent decades, increasing evidence has positioned slow-wave sleep (SWS) as a major actor in neurophysiological phenomena such as glucose metabolism, hormone release, immunity and memory. This proposed role for SWS, coupled with observations of impaired SWS in several pathologies as well as in aging, has led some researchers to implement methods that could specifically enhance SWS. This review aims to gather the current knowledge extending from the cell to the clinic, in order to construct an overview of what is currently known about so-called SWS. We slowly expand the view from the molecular processes underlying SWS to the cell unit and assembly to cortical manifestations. We then describe its role in physiology and cognition to finally assess its association with clinical aspects. Finally, we address practical considerations for several techniques that could be used to manipulate SWS, in order to improve our understanding of SWS and possibly help the development of treatments for SWS clinical disorders.

Introduction Several studies have shown slow wave sleep (SWS) is altered with ageing. However, most of these studies have been conducted in-lab and usually over a single night. In this study, we assessed the evolution of process S with ageing by analysing the dynamics of endogenous and auditory-evoked slow waves in a large population. Methods 300 participants (200 M, 20 - 70 y.o.) were selected from volunteers users wearing a sleep headband for at least 3 nights, meeting the criteria of high signal quality and having no subjective sleep complaints nor being shift-workers. The Dreem headband is a connected device able to monitor EEG signals as well as pulse and movement and performs sleep staging in real-time automatically. Slow waves were detected as large negative deflections on the filtered EEG signals during NREM sleep. The auditory evoked slow waves were done using a previously validated closed-loop procedure. Results In our study, age was strongly correlated with N3 sleep duration (r=-0.34, p Conclusion These results confirmed the in-lab studies showing a heterogeneous alteration of homoeostatic process S with age, as well as a general decrease of slow wave occurrences, that is observed in parallel of a decrease of the probability of evoking slow waves, suggesting a global change in the system responsible for slow wave generation. Support This study was supported by Dreem sas and ANR, FLAG ERA 2015, HPB SLOW-Dyn

Introduction Cognitive-behavioral therapy for insomnia (CBT-I) is the current first-line treatment for insomnia disorder, recommended by the AASM and SRS. Digital versions of CBT-I have been developed and validated to address the need for implementation at scale but still suffer from poor accessibility and compliance. Therefore, the aim of this open-label, Real-World Study (RWS) was to assess the engagement and efficacy of a next-generation CBT-i 6-weeks program. Methods 1304 subjects were included in the analysis between Dec 23rd, 2018 and December, 14th 2019. The main inclusion criteria were having an Insomnia Severity Index ISI ≥ 15 and completion of one week of Dreem program. The variables have been measured by the Dreem headband (DH) for objective variables, and on subjects’ answers to questionnaires for subjective ones. Results The retention during this RWS was 70.4 % (Pre: n = 1304 and Week 4: n = 935). The program led to a clinically significant decrease of 7.42 points on the ISI (p < 0.001). The obj-WASO was reduced by 35% (n = 359, p < 0.001), obj-Awakenings were reduced by 37% (n = 359 p < 0.001), obj-SE was increased by 2.56 points (n = 305, p < 0.001) and obj-SOL was reduced by 22% (n = 359, p < 0.001). The subj-SOL was reduced by 41% (n = 176, p < 0.001), subj-SE was increased by 8.9 points (n =168, p < 0.001), subj-SD was increased by 16% (baseline: 307.50 ± 88.86 min; post 357.07 ± 91.24 min, subj-SD (n = 174, p < 0.001). Conclusion The results of this RWS suggest this insomnia program has a high engagement compared to other digital CBT-I programs and is as effective as traditional in-person CBT-I. This new generation of Insomnia therapy combining hardware, software and therapist serves as an efficient and engaging treatment implementable at scale. Support This study has been supported by Dreem sas.

Background Rapid eye movement sleep behavior disorder and sleepiness precede or accompany idiopathic Parkinson's disease (PD), but their presence in subjects with leucine-rich repeat kinase 2 mutations is unknown. Methods Ten patients with leucine-rich repeat kinase 2-associated PD, four healthy leucine-rich repeat kinase 2 mutation carriers, 20 patients with idiopathic PD, and 12 healthy controls underwent clinical assessments and a nighttime video-polysomnography. Results No sleep changes, no rapid eye movement sleep behavior disorder, or rapid eye movement sleep without atonia was found in the 14 subjects with leucine-rich repeat kinase 2mutations compared with controls, whereas 41% of patients with idiopathic PD had rapid eye movement sleep behavior disorder. Eventually, 20% of patients with leucine-rich repeat kinase 2–associated PD had abnormal periodic leg movements, a frequency similar to the idiopathic PD group frequency. Conclusions The sleep phenotype in leucine-rich repeat kinase 2 mutations parallels that of idiopathic PD, except for absent rapid eye movement sleep behavior disorder here in the presymptomatic and symptomatic stages. © 2015 International Parkinson and Movement Disorder Society

ObjectiveRecent research has shown that auditory closed-loop stimulations can enhance sleep slow oscillations (SO) to improve N3 sleep quality and cognition. Previous studies have been conducted in a lab environment and on a small sample size. The present study aimed at validating and assessing the performance of a novel ambulatory wireless dry-EEG device (WDD), for auditory closed-loop stimulations of SO during N3 sleep at home.Material and MethodsThe performance of the WDD to detect N3 sleep automatically and to send auditory closed-loop stimulations on SO were tested on 20 young healthy subjects who slept with both the WDD and a miniaturized polysomnography (part 1) in both stimulated and sham nights within a double blind, randomized and crossover design.The electrophysiological effects of auditory closed-loop stimulation on delta power increase were assessed after 1 and 10 nights of stimulations on an observational pilot study in the home environment including 90 middle-aged subjects (part 2).ResultsThe sensitivity and specificity of the WDD to automatically detect N3 sleep in real-time were 0.70 and 0.90, respectively. The stimulation accuracy of the SO ascending-phase targeting was 45±52°. The stimulation protocol induced an increase of 39.5 % of delta power after the stimulations. The increase of SO response to auditory stimulations remained at the same level after 10 consecutive nights.ConclusionThe WDD shows good performances to automatically detect in real-time N3 sleep and to send auditory closed-loop stimulations on SO accurately. These stimulations increased the SO amplitude during N3 sleep without any adaptation effect after 10 consecutive nights. This tool provides new perspectives to figure out novel sleep EEG biomarkers in longitudinal studies and can be interesting to conduct broad studies on the effects of auditory stimulations during sleep.

Objective: To characterize medulla oblongata damage using diffusion tensor imaging (DTI) in Parkinson disease (PD) and correlate it with dysfunction of the cardiac sympathetic/vagal balance. Methods: Fifty-two patients with PD and 24 healthy controls were included in the study. All participants underwent clinical examination and 3T MRI using 3D T1-weighted imaging and DTI. DTI metrics were calculated within manually drawn regions of interest. Heart rate variability was evaluated using spectral analysis of the R–R cardiac interval during REM and slow-wave sleep based on continuous overnight electrocardiographic monitoring. Respiratory frequency was measured in 30-second contiguous epochs of REM and slow-wave sleep. The relationships between imaging and cardiac variables were calculated using partial correlations followed by the multiple comparisons permutation approach. Results: The changes in heart rate and respiratory frequency variability from slow-wave sleep to REM sleep in healthy controls were no longer detectable in patients with PD. There were significant increases in the mean ( p = 0.006), axial ( p = 0.006), and radial diffusivities ( p = 0.005) in the medulla oblongata of patients with PD. In PD, diffusion changes were specifically correlated with a lower heart rate and respiratory frequency variability during REM sleep. Conclusions: This study provides evidence that medulla oblongata damage underlies cardiac sympathetic/vagal balance and respiratory dysfunction in patients with PD.

Rapid eye movement sleep behavior disorder and sleepiness precede or accompany idiopathic Parkinson's disease (PD), but their presence in subjects with leucine-rich repeat kinase 2 mutations is unknown.Ten patients with leucine-rich repeat kinase 2-associated PD, four healthy leucine-rich repeat kinase 2 mutation carriers, 20 patients with idiopathic PD, and 12 healthy controls underwent clinical assessments and a nighttime video-polysomnography.No sleep changes, no rapid eye movement sleep behavior disorder, or rapid eye movement sleep without atonia was found in the 14 subjects with leucine-rich repeat kinase 2mutations compared with controls, whereas 41% of patients with idiopathic PD had rapid eye movement sleep behavior disorder. Eventually, 20% of patients with leucine-rich repeat kinase 2-associated PD had abnormal periodic leg movements, a frequency similar to the idiopathic PD group frequency.The sleep phenotype in leucine-rich repeat kinase 2 mutations parallels that of idiopathic PD, except for absent rapid eye movement sleep behavior disorder here in the presymptomatic and symptomatic stages.

Objectif L’objectif de cette etude est d’evaluer l’efficacite d’une contre-mesure apportee par des techniques militaires pour optimiser la sieste de volontaires sains sur leur lieu de travail. Plus particulierement, l’efficacite sur la latence d’endormissement et sur la profondeur du sommeil d’une sieste accompagnee par des suggestions hypnotiques, dans le cadre d’un programme d’optimisation du potentiel (TOP), en comparaison a une sieste « sans TOP » a ete investiguee. Methodes Onze volontaires sains (9H et 2F, 37–52 ans) equipes d’une PSG miniaturisee (3 EEG : F3, C3, O1), 1 EOG et 1 EMG se pretent a 2 conditions de siestes : 4 siestes « sans TOP » de 30 min et 4 siestes de 30 min accompagnees d’un programme TOP. Resultats Le pourcentage de temps total de sommeil, le % de temps passe en N2 et le % de temps passe en N3 augmentent respectivement de 11, 11 et 8 % lorsque la seance est dirigee par un instructeur TOP par rapport a une sieste sans TOP. Ces resultats sont confirmes par l’analyse par sieste. L’evaluation individuelle montre que le benefice de ce programme TOP s’applique a 7 sujets sur 11 quant a l’augmentation du % de temps de sommeil, a 8 sujets quant au %N2 et a 6 sujets quant au %N3. Conclusion L’utilisation des TOP et plus particulierement de la suggestion hypnotique, apparait comme une maniere efficace d’optimiser un temps court de sieste (30 min) en augmentant a la fois la duree totale de sommeil et sa profondeur, chez plus de la moitie des sujets.