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Objective: Posttrauma nightmares are recurring nightmares that begin after a traumatic experience. Research has only recently begun to identify variables that predict posttrauma nightmare occurrences. Research has identified presleep arousal-cognitive (PSA-C) and presleep arousal physiological (PSA-PHYS), sleep onset latency (SOL), and sleep-disordered breathing (SDB) as potential predictors of posttrauma nightmares. However, previous research includes methodological limitations, such as a lack of physiological measures and a homogeneous sample. To replicate previous findings and increase generalizability, the current study investigated predictors of nightmare occurrences in a sample of male inpatient veterans with mixed-trauma history., Method: Participants ( n = 15) completed an initial assessment battery and seven consecutive days of pre and postsleep diaries, including measures of posttrauma nightmare triggers and posttrauma nightmare occurrences. Portable objective measurements of sleep and presleep states were used to examine sleep quality and physical arousal., Results: Analyses revealed that PSA-C and SOL both predicted posttrauma nightmare occurrences and that PSA-PHYS was significantly higher on nights when nightmares occurred., Conclusion: Results replicate earlier research which posits that PSA and SOL play a role in triggering the occurrence of posttrauma nightmares. It should be noted that the sample was relatively small, warranting cautious interpretation of results. However, when taken together with the findings of the replicated study, results could suggest the plausibility of therapies targeting presleep cognitions, SOL, and presleep arousal in the treatment of posttrauma nightmares. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

The present study examined the relationship between subjective sleep onset latency (SOL), sleep structure, changes in skin and body temperature, and subjective evaluation of sleep in healthy young adults to elucidate the pathophysiological mechanisms of insomnia. A total of 28 participants (age 21.54 [0.50] years) with no sleep problems participated in a 1-h polysomnographic recording that obtained objective sleep parameters during the daytime while skin and body temperatures were recorded. The distal-proximal skin temperature gradient (DPG) was calculated. Subjective parameters, such as subjective SOL, sleep time, and restorative sleepiness, were evaluated before and after sleep. Most participants estimated their sleep latency as being longer than their actual SOL (13.7 versus 7.6 min). Objective SOL was significantly correlated with each sleep stage parameter whereas subjective SOL was negatively correlated with Stage N2 sleep duration (Rho = -0.454, p = 0.020), slow-wave activity and delta power (Rho = -0.500, p = 0.011 and Rho = -0.432, p = 0.031, respectively), and ΔDPG (the degree of reduction of heat loss before and after lights-off). Stepwise regression analysis showed that ΔDPG was the strongest predictive factor in explaining the length of subjective SOL. The degree of heat dissipation before and after lights-off contributed most to the sensation of falling asleep in healthy young adults. This finding may be helpful for elucidating the physiological mechanisms of insomnia and its treatment., (© 2024 European Sleep Research Society.)

This systematic review aims to identify the sleep parameters of Olympic athletes and the instruments used to assess and monitor the sleep of these athletes. The search was conducted until February 2023 and was performed in PubMed, Web of Science, and Scopus databases. This systematic review has included studies that investigated at least one of the following sleep parameters: total sleep time (TST), sleep onset latency (SOL), sleep efficiency (SE), awakenings after sleep onset (WASO), quality of sleep, daytime sleepiness, and chronotype; the participants were Olympic athletes. The search returned a total of 280 studies. After screening based on exclusion and inclusion criteria, 11 studies were included. The main results demonstrate that Olympic athletes have TST of 06:10 h, SE of 84%, SOL of 28 min, and WASO of 49 min. The most predominant chronotype is indifferent; over half of the athletes have poor sleep quality and complaints. Furthermore, actigraphy was the most used method to assess sleep. It is concluded that Olympic athletes have TST, SE, and WASO poor than the recommended values. In addition, sleep complaints and poor sleep quality were also observed. Among the objective sleep assessment methods, actigraphy was the method most frequently used in this population., Competing Interests: The authors declare that they have no conflict of interest., (Thieme. All rights reserved.)

Objectives: Discrepancies between sleep diaries and sensor-based sleep parameters are widely recognized. This study examined the effect of showing sensor-based sleep parameters while completing a daily diary. The provision of sensor-based data was expected to reduce variance but not change the mean of self-reported sleep parameters, which would in turn align better with sensor-based data compared to a control diary., Method: In a crossover study, 24 volunteers completed week-long periods of control diary (digital sleep diary without sensor-based data feedback) or integrated diary (diary with device feedback), washout, and then the other diary condition., Results: The integrated diary reduced self-reported total sleep time (TST) by <10 minutes and reduced variance in TST. The integrated diary did not impact mean sleep onset latency (SOL) and, unexpectedly, the variance in SOL increased. The integrated diary improved both bias and limits of agreement for SOL and TST., Conclusions: Integration of wearable, sensor-based device data in a sleep diary has little impact on means, mixed evidence for less variance, and better agreement with sensor-based data than a traditional diary. How the diary impacts reporting and sensor-based sleep measurements should be explored.

Objective: MSLT results are known to be affected by multiple factors including sleep time, frequency of nighttime arousals, and medications intake. Although being the main synchronizer of sleep and wakefulness, daylight duration effects on MSLT have not been examined. Burlington, Vermont, USA experiences great variations in daylight duration, ranging from 8 h 50 min to 15 h 33 min of daylight. The aim of this study was to test the hypothesis that there would be photoperiod duration effects on MSLTs performed during short daylight (short daylight studies, SDS) vs. long daylight (long daylight studies, LDS) from 2013 to 2023 in our sleep laboratory., Methods: We identified and analyzed 37 SDS (daylight 530-560 min) and 36 LDS (daylight 903-933 min) from our database. Groups of SDS and LDS results were compared using non-paired student T test, Chi-Square and non-parametric Mann Whitney U Test., Results: Average daylight duration was 15 h 18 ± 14.6 min for LDS and 8 h 57 ± 18 min for SDS. Two groups did not differ in terms of the age, gender, BMI and race of patients studied. Mean total sleep time and sleep efficiency during PSG preceding MSLT, and MSLT mean sleep onset latency did not significantly differ for the two groups. However, SDS MSLT naps had significantly more sleep onset REM periods (SOREMP), and distribution of the number of SOREMP captured during MSLT was different for SDS and LDS groups. Differences of SDS and LDS results did not relate to sleep architecture of the overnight PSG as analysis of sleep and REM latency and relative percentages of N1, N2, REM, and N3 was not significantly different between SDS and LDS. The two groups showed difference in arousal indexes during N1 and REM sleep., Conclusions: Daylight duration may impact MSLT results and should probably be accounted for in MSLT interpretation. Attention to photoperiod could be considered in MSLT guidelines, if our results are replicated in larger samples., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Purpose: Sleep State Misperception (SSM) is described as the tendency of Insomnia Disorder (ID) patients to overestimate Sleep Latency (SL) and underestimate Total Sleep Time (TST). Literature exploring topographical components in ID with SSM is scarce and does not allow us to fully understand the potential mechanisms underlying this phenomenon. This study aims to evaluate the existence of sleep EEG topography alterations in ID patients associated with SSM compared to Healthy Controls (HC), focusing on two distinct periods: the Sleep Onset (SO) and the whole night., Methods: Twenty ID patients (mean age: 43.5 ± 12.7; 7 M/13F) and 18 HCs (mean age: 41.6 ± 11.9; 8 M/10F) underwent a night of Polysomnography (PSG) and completed sleep diaries the following morning upon awakening. Two SSM indices, referring to the misperception of SL (SLm) and TST (TSTm), were calculated by comparing objective and subjective sleep indices extracted by PSG and sleep diary. According to these indices, the entire sample was split into 4 sub-groups: ID +SLm vs HC -SLm; ID +TSTm vs HC -TSTm., Results: Considering the SO, the two-way mixed-design ANOVA showed a significant main effect of Groups pointing to a decreased delta/beta ratio in the whole scalp topography. Moreover, we found a significant interaction effect for the sigma and beta bands. Post Hoc tests showed higher sigma and beta power in anterior and temporo-parietal sites during the SO period in IDs +SLm compared to HC -SLm. Considering the whole night, the unpaired t-test revealed in IDs +TSTm significantly lower delta power during NREM, and lower delta/beta ratio index during NREM and REM sleep compared to HCs -TSTm. Finally, we found diffuse significant negative correlations between SSM indices and the delta/beta ratio during SO, NREM, and REM sleep., Conclusion: The main finding of the present study suggests that higher SL overestimation and TST underestimation are both phenomena related to diffuse cortical hyperarousal interpreted as a sleep state-independent electrophysiological correlate of the SSM, both during the SO and the whole night., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper. The authors declare the absence of financial interests/personal relationships which may be considered as potential competing interests., (Copyright © 2024. Published by Elsevier Inc.)

This study aimed to explore the potential mediating role of sleep quality in the effect of physical activity (PA) intervention for improving executive functions (EFs) in children with attention-deficit hyperactivity disorder (ADHD). Participants aged 6 to 12 years old with a formal ADHD diagnosis were recruited from a local hospital. A total of 80 eligible children with ADHD were randomized to an intervention group for 12 consecutive weeks of PA training (three times per week, 60 min per session) (n = 40; Mage = 8.37, 75% boys) or a wait-list control group (n = 40; Mage = 8.29, 80% boys). Three core EFs (inhibitory control, working memory, and cognitive flexibility) were assessed by neurocognitive tasks, and sleep quality was measured by the Chinese version of the Pittsburgh Sleep Quality Index. The bootstrapping method was used to test PA intervention effects on EFs and on potential variables of sleep quality after intervention and to test whether there were indirect effects of the intervention on EFs via mediators of sleep. The results showed that the PA intervention had a direct effect on sleep latency reduction (β = - 0.26, 95%CI - 0.47 to - 0.06) and cognitive flexibility improvement (decrease in completion time) (β = - 0.30, 95%CI - 0.50 to - 0.09). Furthermore, change in sleep latency significantly mediated the effects of PA intervention on cognitive flexibility (β = - 0.084, 95%CI - 0.252 to - 0.001). The findings suggest that sleep latency could be a crucial behavioral mediator of PA intervention in improving cognitive flexibility among children with ADHD., (© 2023. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.)

Sleep onset latency (SOL) is an important factor relating to the sleep quality of a subject. Therefore, accurate prediction of SOL is useful to identify individuals at risk of sleep disorders and to improve sleep quality. In this study, we estimate SOL distribution and falling asleep function using an electroencephalogram (EEG), which can measure the electric field of brain activity. We proposed a Multi Ensemble Distribution model for estimating Sleep Onset Latency (MEDi-SOL), consisting of a temporal encoder and a time distribution decoder. We evaluated the performance of the proposed model using a public dataset from the Sleep Heart Health Study. We considered four distributions, Normal, log-Normal, Weibull, and log-Logistic, and compared them with a survival model and a regression model. The temporal encoder with the ensemble log-Logistic and log-Normal distribution showed the best and second-best scores in the concordance index (C-index) and mean absolute error (MAE). Our MEDi-SOL, multi ensemble distribution with combining log-Logistic and log-Normal distribution, shows the best score in C-index and MAE, with a fast training time. Furthermore, our model can visualize the process of falling asleep for individual subjects. As a result, a distribution-based ensemble approach with appropriate distribution is more useful than point estimation.

Sleep symptoms, including excessive sleepiness, are frequently reported by patients with functional motor disorders (FMD). We aimed to classify the comorbid sleep disorders in FMD, and to investigate the relationship between subjective sleepiness and objective measures of hypersomnia, comparing them with data from people with central hypersomnia. A total of 37 patients (mean [SD] age 46.4 [11.2] years) with clinically definite FMD, and 17 patients (mean [SD] age 41.1 [11.6] years) with central hypersomnia underwent structured medical and sleep history, neurological examination, polysomnography, multiple sleep latency test (MSLT), and questionnaires assessing sleepiness, fatigue, and depression. In all, 23 patients with FMD (62%) reported excessive daytime sleepiness. Evidence of specific sleep disorders was identified in our cohort, with 35% having restless legs syndrome; 49% obstructive sleep apnea; and 8% periodic limb movements in sleep; however, the presence of these disorders was not correlated with subjective sleepiness. Patients with FMD with self-reported sleepiness reported higher fatigue (p = 0.002), depression (p = 0.002), and had longer sleep latencies in the MSLT (p < 0.001) compared to the patients with central hypersomnia. No correlation was found between subjective and objective sleepiness in either group. Fatigue positively correlated with self-reported sleepiness in patients with FMD (p < 0.001). This study did not find objective correlates of increased sleepiness in patients with FMD. While sleep abnormalities were found to be common in FMD, they were not correlated with self-reports of excessive sleepiness. Positive correlations between self-reported sleepiness and fatigue support the current unified model of non-motor symptoms in FMD., (© 2023 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

The Maintenance of Wakefulness Test is widely used to objectively assess sleepiness and make safety-related decisions, but its interpretation is subjective and normative values remain debated. Our work aimed to determine normative thresholds in non-subjectively sleepy patients with well-treated obstructive sleep apnea, and to assess intra- and inter-scorer variability. We included maintenance of wakefulness tests of 141 consecutive patients with treated obstructive sleep apnea (90% men, mean (SD) age 47.5 (9.2) years, mean (SD) pre-treatment apnea-hypopnea index of 43.8 (20.3) events/h). Sleep onset latencies were independently scored by two experts. Discordant scorings were reviewed to reach a consensus and half of the cohort was double-scored by each scorer. Intra- and inter-scorer variability was assessed using Cohen's kappa for 40, 33, and 19 min mean sleep latency thresholds. Consensual mean sleep latencies were compared between four groups according to subjective sleepiness (Epworth Sleepiness Scale score < versus ≥11) and residual apnea-hypopnea index (< versus ≥15 events/h). In well-treated non-sleepy patients (n = 76), the consensual mean (SD) sleep latency was 38.4 (4.2) min (lower normal limit [mean - 2SD] = 30 min), and 80% of them did not fall asleep. Intra-scorer agreement on mean sleep latency was high but inter-scorer was only fair (Cohen's kappa 0.54 for 33-min threshold, 0.27 for 19-min threshold), resulting in changes in latency category in 4%-12% of patients. A higher sleepiness score but not the residual apnea-hypopnea index was significantly associated with a lower mean sleep latency. Our findings suggest a higher than usually accepted normative threshold (30 min) in this context and emphasise the need for more reproducible scoring approaches., (© 2023 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

Objective: To test the hypothesis of the difference between 3 means of sleep latency (SL) during falling asleep: accompanied by audio stimulus embedded with binaural beats (BB); after listening to suggestive body relaxation instructions; accompanied by audio stimulus embedded with BB after listening to suggestive body relaxation instructions (that is the combination of 1 and 2)., Material and Methods: For the purpose of the study, a special Android application was developed and installed on the subjects' individual smartphones. The application assumed screen tapping test to control for fall-asleep process. The data of 63 subjects presented with the 3 types of sound stimuli mentioned above in a counterbalanced scheme were analyzed., Results: Statistical analysis confirmed the initial hypothesis about the dependence of LS on the type of sound stimulus ( p <0.05). Pairwise SL comparison showed reliable difference between stimuli (3) - 1149±113 s, and (1) - 1469±89 s ( p <0.01). SL for the stimulus (2) had an intermediate value of 1269±112 s (difference from (1) at a trend level)., Conclusion: The use of background sound embedded with BBs enhances the effect of suggestive instructions to improve sleep. But it is the suggestion as a psychotherapeutic technique that is determinant.

To evaluate sleep quality, it is necessary to monitor overnight sleep duration. However, sleep monitoring typically requires more than 7 hours, which can be inefficient in termxs of data size and analysis. Therefore, we proposed to develop a deep learning-based model using a 30 sec sleep electroencephalogram (EEG) early in the sleep cycle to predict sleep onset latency (SOL) distribution and explore associations with sleep quality (SQ). We propose a deep learning model composed of a structure that decomposes and restores the signal in epoch units and a structure that predicts the SOL distribution. We used the Sleep Heart Health Study public dataset, which includes a large number of study subjects, to estimate and evaluate the proposed model. The proposed model estimated the SOL distribution and divided it into four clusters. The advantage of the proposed model is that it shows the process of falling asleep for individual participants as a probability graph over time. Furthermore, we compared the baseline of good SQ and SOL and showed that less than 10 minutes SOL correlated better with good SQ. Moreover, it was the most suitable sleep feature that could be predicted using early EEG, compared with the total sleep time, sleep efficiency, and actual sleep time. Our study showed the feasibility of estimating SOL distribution using deep learning with an early EEG and showed that SOL distribution within 10 minutes was associated with good SQ.

Background: The diagnosis of narcolepsy is based on clinical information, combined with polysomnography (PSG) and the Multiple Sleep Latency Test (MSLT). PSG and the MSLT are moderately reliable at diagnosing narcolepsy type 1 (NT1) but unreliable for diagnosing narcolepsy type 2 (NT2). This is a problem, especially given the increased risk of a false-positive MSLT in the context of circadian misalignment or sleep deprivation, both of which commonly occur in the general population., Aim: We aimed to clarify the accuracy of PSG/MSLT testing in diagnosing NT1 versus controls without sleep disorders. Repeatability and reliability of PSG/MSLT testing and temporal changes in clinical findings of patients with NT1 versus patients with hypersomnolence with normal hypocretin-1 were compared., Method: 84 patients with NT1 and 100 patients with non-NT1-hypersomnolence disorders, all with congruent cerebrospinal fluid hypocretin-1 (CSF-hcrt-1) levels, were included. Twenty-five of the 84 NT1 patients and all the hypersomnolence disorder patients underwent a follow-up evaluation consisting of clinical assessment, PSG, and a modified MSLT. An additional 68 controls with no sleep disorders were assessed at baseline., Conclusion: Confirming results from previous studies, we found that PSG and our modified MSLT accurately and reliably diagnosed hypocretin-deficient NT1 (accuracy = 0.88, reliability = 0.80). Patients with NT1 had stable clinical and electrophysiological presentations over time that suggested a stable phenotype. In contrast, the PSG/MSLT results of patients with hypersomnolence, and normal CSF-hcrt-1 had poor reliability (0.32) and low repeatability., Competing Interests: Declaration of competing interest Dr. Mignot reports non-financial support from Idorsia Pharmaceuticals Ltd, and personal fees from Jazz Pharmaceuticals, Alairion, ALPCO, INEXIA, Merck, Orexia, Dreem, and Sunovion during the course of the study. Dr. Kornum is a founder of Ceremedy and reports personal fees from Orexia Therapeutics and Novartis. Dr. Torstensen, Dr. Barloese, Dr. Jennum, and Dr. Wanscher have nothing to disclose., (Copyright © 2023 The Authors. Published by Elsevier B.V. All rights reserved.)

Objective: The complexity and delay of the diagnosis of narcolepsy require several diagnostic tests and invasive procedures such as lumbar puncture. Our study aimed to determine the changes in muscle tone (atonia index, AI) at different levels of vigilance during the entire multiple sleep latency test (MSLT) and each nap in people with narcolepsy type 1 (NT1) and 2 (NT2) compared with other hypersomnias and its potential diagnostic value., Methods: Twenty-nine patients with NT1 (11 M 18F, mean age 34.9 years, SD 16.8) and sixteen with NT2 (10 M 6F, mean age 39 years, SD 11.8) and 20 controls with other hypersomnias (10 M, 10F mean age 45.1 years, SD 15.1) were recruited. AI was evaluated at different levels of vigilance (Wake and REM sleep) in each nap and throughout the MSLT of each group. The validity of AI in identifying patients with narcolepsy (NT1 and NT2) was analyzed using receiver operating characteristic (ROC) curves., Results: AI during wakefulness (WAI) was significantly higher in the narcolepsy groups (NT1 and NT2 p < 0.001) compared to the hypersomniac group. AI during REM sleep (RAI) (p = 0.03) and WAI in nap with sudden onsets of REM sleep periods (SOREMP) (p = 0.001) were lower in NT1 than in NT2. The ROC curves showed high AUC values for WAI (NT1 0.88; Best Cut-off > 0.57, Sensitivity 79.3 % Specificity 90 %; NT2 0.89 Best Cut-off > 0.67 Sensitivity 87.5 % Specificity 95 %; NT1 and NT2 0.88 Best Cut-off > 0.57 Sensitivity 82.2 % Specificity 90 %) in discriminating subjects suffering from other hypersomnias. RAI and WAI in nap with SOREMP showed a poor AUC value (RAI AUC: 0.7 Best cutoff 0.7 Sensitivity 50 % Specificity 87.5 %; WAI in nap before SOREMP AUC: 0.66, Best cut-off < 0.82 sensitivity 61.9 % and specificity 67.35 %) differentiating NT1 and NT2., Conclusions: WAI may represent an encouraging electrophysiological marker of narcolepsy and suggests a vulnerable tendency to dissociative wake / sleep dysregulation lacking in other forms of hypersomnia., Significance: AI during wakefulness may help distinguish between narcolepsy and other hypersomnias., (Copyright © 2023 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

Purpose: Narcolepsy is a chronic disorder and its phenotype is dichotomized into narcolepsy type 1 (NT1) and narcolepsy type 2 (NT2). The clinical course and pathophysiological mechanisms of these two clinical entities and their differences are not adequately defined. This study aimed to explore the differential longitudinal patterns of polysomnography (PSG) and multiple sleep latency test (MSLT) in NT1 and NT2., Methods: In this retrospective study demographic characteristics, PSG, and MSLT parameters at baseline and follow-up were compared between NT1 and NT2 patients. Patients with both follow-up MSLT and PSG were selected for sub-group analysis. Baseline and follow-up MSLT and PSG parameters were compared., Results: Of 55 patients with narcolepsy, mean follow-up periods were 7.4 ± 3.5 years for NT1 and 5.5 ± 2.9 for NT2. Demographic data showed increased body mass index and prevalence of sleep paralysis in NT1. Baseline PSG characteristics between NT1 and NT2 showed decreased sleep latency (p = 0.016) and REM latency (p = 0.046) in NT1 group when compared with NT2. Nocturnal SOREMP on PSG was more prevalent in NT1 (p = 0.017), and half of NT2 patients with nocturnal SOREMP on PSG changed their diagnoses to NT1. On follow-up PSG, NT1 displayed reductions in sleep stage N2 (p = 0.006) and N3 (p = 0.048), while wake after sleep onset (WASO) (p = 0.023) and apnea-hypopnea index (AHI) (p = 0.007) were significantly increased., Conclusion: Differential MSLT and PSG characteristics of NT1 and NT2 in at baseline and follow-up indicate that NT1 and NT2 are distinct disease phenotypes, and that they present with a contrasting course of disease., (© 2021. The Author(s), under exclusive licence to Springer Nature Switzerland AG.)

Previous studies have shown that the synchronization of electroencephalogram (EEG) signals is found during propofol-induced general anesthesia, which is similar to that of slow-wave sleep (SWS). However, a complete understanding is lacking in terms of the characteristics of EEG changes in rats after propofol administration and whether propofol acts through natural sleep circuits. Here, we examined the characteristics of EEG patterns induced by intraperitoneal injection of propofol in rats. We found that high (10 mg/kg) and medium (5 mg/kg) doses of propofol induced a cortical EEG of low-frequency, high-amplitude activity with rare electromyographic activity and markedly shortened sleep latency. The high dose of propofol increased deep slow-wave sleep (SWS2) to 4 h, as well as the number of large SWS2 bouts (>480 s), their mean duration and the peak of the power density curve in the delta range of 0.75-3.25 Hz. After the medium dose of propofol, the total number of wakefulness, light slow-wave sleep (SWS1) and SWS2 episodes increased, whereas the mean duration of wakefulness decreased. The high dose of propofol significantly increased c-fos expression in the ventrolateral preoptic nucleus (VLPO) sleep center and decreased the number of c-fos-immunoreactive neurons in wake-related systems including the tuberomammillary nucleus (TMN), perifornical nucleus (PeF), lateral hypothalamic nucleus (LH), ventrolateral periaqueductal gray (vPAG) and supramammillary region (SuM). These results indicated that the high dose of propofol produced high-quality sleep by increasing SWS2, whereas the medium dose produced fragmented and low-quality sleep by disrupting the continuity of wakefulness. Furthermore, sleep-promoting effects of propofol are correlated with activation of the VLPO cluster and inhibition of the TMN, PeF, LH, vPAG and SuM., (Copyright © 2021 Elsevier B.V. All rights reserved.)

Purpose: To investigate the possible role of physical activity (PA) on sleep disturbance in breast cancer patients., Methods: Literature in PubMed, Embase, and the Cochrane Library was systematically searched until January 30, 2020. Randomized controlled trials that focused on the role of PA interventions on sleep disturbance were selected. The main outcome measures included the global Pittsburgh Sleep Quality Index (PSQI) score and PSQI subscales. Subgroup analysis was performed based on the study area and intervention time. The stability and authenticity of the results were measured by sensitivity analysis and publication bias analysis, respectively., Results: Six articles were included in this meta-analysis. There were no significant differences in global PSQI scores between the PA intervention group and the usual care group (P = 0.057). As for PSQI subscales, PA intervention could improve sleep quality (weighted mean difference = 0.22; 95% confidence interval 0.04-0.40; P = 0.018). There were no significant differences in sleep duration, sleep medication, sleep latency, habitual sleep efficiency, and daytime dysfunction between the two groups (all P > 0.05)., Conclusion: PA serves as an effective intervention to improve sleep quality.

Daytime napping is a common practice in high-performance athletes, and is widely assumed to reflect sleepiness arising from sports-related sleep debt. The possibility that athlete naps may also be indicative of 'sleepability', a capacity to nap on demand that is only weakly related to homeostatic sleep pressure, has not previously been tested. The present study compared daytime sleep latencies in high-performance athletes and non-athlete controls using a single nap opportunity model. Elite ( n  = 10), and sub-elite ( n  = 10) athletes, and non-athlete controls ( n  = 10) attended the laboratory for a first adaption trial, and a subsequent experimental trial. Subjective sleepiness was assessed using the Karolinska Sleepiness Scale (KSS) at 14:00, 14:30 and immediately prior to a 20-minute nap opportunity at 15:00. Sleep latencies were measured using polysomnography, and defined as the time from lights out to the first epoch of any stage of sleep (N1, N2, N3, REM). In unadjusted comparisons with non-athlete controls, elite athletes showed significantly shorter sleep latencies in both the adaptation ( p  < 0.05) and experimental trials ( p  < 0.05). These significant differences were maintained in models controlling for pre-trial KSS scores and pre-trial total sleep time (all p  < 0.05). Sleep latency scores for sub-elite athletes showed similar trends, but were more labile. These results are consistent with a conclusion that, among elite athletes, napping behaviour can reflect sleepability and may not necessarily result from nocturnal sleep disruption and daytime sleepiness.

Objective: The current study investigated the behavioral, cognitive, and electrophysiological impact of mild (only a few hours) and acute (one night) sleep loss via simultaneously recorded behavioural and physiological measures of vigilance., Methods: Participants (N = 23) came into the lab for two testing days where their brain activity and vigilance were recorded and assessed. The night before the testing session, participants either slept from 12am to 9am (Normally Rested), or from 1am to 6am (Sleep Restriction)., Results: Vigilance was reduced and sleepiness was increased in the Sleep Restricted vs. Normally Rested condition, and this was exacerbated over the course of performing the vigilance task. As well, sleep restriction resulted in more intense alpha bursts. Lastly, EEG spectral power differed in Sleep Restricted vs. Normally Rested conditions as sleep onset progressed, particularly for frequencies reflecting arousal (e.g., delta, alpha, beta)., Conclusions: The findings of this study suggest that only one night of mild sleep loss significantly increases sleepiness and, importantly, reduces vigilance. In addition, this sleep loss has a clear impact on the physiology of the brain in ways that reflect reduced arousal., Significance: Understanding the neural correlates and cognitive processes associated with loss of sleep may lead to important advancements in identifying and preventing deleterious or potentially dangerous, sleep-related lapses in vigilance., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

This study investigated the effect of various cycling intensities on sleep-related parameters in healthy young adults with intermediate chronobiological phenotype. Ten recreationally trained male volunteers underwent an evening i) moderate-intensity continuous training (MICT; 45 min at 70% W max ), ii) high-intensity interval training (HIIT; 10 × 1 min at 90% W max ), iii) sprint interval training (SIT; 6 × 20 sec at 140% W max ) or iv) a non-exercise (CON) trial in randomized, counter-balanced and crossover order. At baseline, somatometric data, maximum oxygen uptake and chronotype were evaluated. Sleep-related indices and daily activity were recorded by a multi-sensor activity monitor. Total sleep time was longer after SIT compared to CON and MICT ( p < 0.05). Sleep efficiency was higher in SIT than in CON ( p < 0.05). Sleep onset latency did not differ among trials. Wake after sleep onset was decreased after SIT compared to CON ( p = 0.049). No differences were found for bedtime among trials. Wake time was earlier in the MICT trial compared to CON ( p = 0.026). Evening cycling exercise -independently of intensity- did not impair sleep of individuals with intermediate chronobiological phenotype. Furthermore, a single SIT session improved sleep quantity and continuation of individuals with this specific chronotype.

Objective: Aim of the present study is to investigate the alterations of brain networks derived from EEG analysis in pre- and post-sleep onset conditions after 40 h of sleep deprivation (SD) compared to sleep onset after normal sleep in 39 healthy subjects., Methods: Functional connectivity analysis was made on electroencelographic (EEG) cortical sources of current density and small world (SW) index was evaluated in the EEG frequency bands (delta, theta, alpha, sigma and beta)., Results: Comparing pre- vs. post-sleep onset conditions after a night of SD a significant decrease of SW in delta and theta bands in post-sleep onset condition was found together with an increase of SW in sigma band. Comparing pre-sleep onset after sleep SD versus pre-sleep onset after a night of normal sleep a decreased of SW index in beta band in pre-sleep onset in SD compared to pre-sleep onset in normal sleep was evidenced., Conclusions: Brain functional network architecture is influenced by the SD in different ways. Brain networks topology during wake resting state needs to be further explored to reveal SD-related changes in order to prevent possible negative effects of SD on behaviour and brain function during wakefulness., Significance: The SW modulations as revealed by the current study could be used as an index of an altered balance between brain integration and segregation processes after SD., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2020 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.)

The importance of dogs (Canis familiaris) in sleep research is primarily based on their comparability with humans. In spite of numerous differences, dogs' comparable sleep pattern, as well as several phenotypic similarities on both the behavioural and neural levels, make this species a most feasible model in many respects. Our aim was to investigate whether the so-called first-night effect, which in humans manifests as a marked macrostructure difference between the first and second sleep occasions, can be observed in family dogs. We used a non-invasive polysomnographic method to monitor and compare the characteristics of dogs' (N = 24) 3-hr-long afternoon naps on three occasions at the same location. We analysed how sleep macrostructure variables differed between the first, second and third occasions, considering also the effects of potential confounding variables such as the dogs' age and sleeping habits. Our findings indicate that first-night effect is present in dogs' sleep architecture, although its specifics somewhat deviate from the pattern observed in humans. Sleep macrostructure differences were mostly found between occasions 1 and 3; dogs slept more, had less wake after the first drowsiness episode, and reached drowsiness sleep earlier on occasion 3. Dogs, which had been reported to sleep rarely not at home, had an earlier non-rapid eye movement sleep, a shorter rapid eye movement sleep latency, and spent more time in rapid eye movement sleep on occasion 3, compared with occasion 1. Extending prior dog sleep data, these results help increase the validity of further sleep electroencephalography investigations in dogs., (© 2020 The Authors. Journal of Sleep Research published by John Wiley & Sons Ltd on behalf of European Sleep Research Society.)

Introduction: We investigated and compared associations of objective estimates of sleep and 24-hour activity rhythms using actigraphy with risk of dementia., Methods: We included 1322 non-demented participants from the prospective, population-based Rotterdam Study cohort with valid actigraphy data (mean age 66 ± 8 years, 53% women), and followed them for up to 11.2 years to determine incident dementia., Results: During follow-up, 60 individuals developed dementia, of which 49 had Alzheimer's disease (AD). Poor sleep as indicated by longer sleep latency, wake after sleep onset, and time in bed and lower sleep efficiency, as well as an earlier "lights out" time, were associated with increased risk of dementia, especially AD. We found no associations of 24-hour activity rhythms with dementia risk., Discussion: Poor sleep, but not 24-hour activity rhythm disturbance, is associated with increased risk of dementia. Actigraphy-estimated nighttime wakefulness may be further targeted in etiologic or risk prediction studies., (© 2020 The Authors. Alzheimer's & Dementia published by Wiley Periodicals LLC on behalf of Alzheimer's Association.)

Current sport-scientific studies mostly neglect the assessment of sleep architecture, although the distribution of different sleep stages is considered an essential component influencing an athlete's recovery and performance capabilities. A mobile, self-applied tool like the SOMNOwatch plus EEG might serve as an economical and time-friendly alternative to activity-based devices. However, self-application of SOMNOwatch plus EEG has not been validated against conventional polysomnography (PSG) yet. For evaluation purposes, 25 participants (15 female, 10 male; M age  = 22.92 ± 2.03 years) slept in a sleep laboratory on two consecutive nights wearing both, conventional PSG and SOMNOwatch plus EEG electrodes. Sleep parameters and sleep stages were compared using paired t -tests and Bland-Altman plots. No significant differences were found between the recordings for Sleep Onset Latency, stages N1 to N3 as well as Rapid Eye Movement stage. Significant differences (Bias [95%-confidence interval]) were present between Total Sleep Time (9.95 min [-29.18, 49.08], d =  0.14), Total Wake Time (-13.12 min [-47.25, 23.85], d  = -0.28), Wake after Sleep Onset (-11.70 min [-47.25, 23.85], d  = -0.34) and Sleep Efficiency (2.18% [-7.98, 12.34], d  = 0.02) with small effect sizes. Overall, SOMNOwatch plus EEG can be considered a valid and practical self-applied method for the examination of sleep. In sport-scientific research, it is a promising tool to assess sleep architecture in athletes; nonetheless, it cannot replace in-lab PSG for all clinical or scientific purposes.

BACKGROUND The aim of this study was to understand the changes in psychological factors and sleep status of front-line medical staff in the fight against COVID-19 and provide evidence of exercise interventions to relieve psychological stress and improve sleep status for medical staff. MATERIAL AND METHODS A survey study was conducted among 120 front-line medical staff in the fight against COVID-19, of which 60 medical staff worked at the designated hospital (experimental group) and 60 medical staff worked at the non-designated hospital (control group). The Symptom Checklist 90 (SCL-90), Self-rating Anxiety Scale (SAS), Self-rating Depression Scale (SDS), and PTSD Checklist-Civilian Version (PCL-C) were used to assess mental status. Sleep status was assessed using the Pittsburgh Sleep Quality Index (PSQI). RESULTS SCL-90 scores of somatization, depression, anxiety, and terror were higher than normal in front-line medical staff at the designated hospital. The SAS (45.89±1.117), SDS (50.13±1.813), and PCL-C (50.13±1.813) scores in the experimental group were higher than the normal control group, and were significantly different from those in the control group on SDS and PCL-C scales (P<0.05). The total average PSQI of the experimental group was 16.07±3.761, indicating that the sleep quality was poor. Among them, participants with moderate insomnia reached 61.67%, and participants with severe insomnia reached 26.67%. CONCLUSIONS There are psychological symptoms and sleep symptoms in front-line medical staff who participate in the fight against COVID-19, and they affect each other. Hospitals should improve emergency management measures, strengthen psychological counseling for clinical front-line medical staff, strengthen exercise intervention, and improve their sleep quality and mental health.

Objective: Sleep difficulties are highly prevalent and often persistent in young children, but sometimes parents are worried about sleep symptoms that belong to the normative range rather than to actual disturbances. Therefore, the aim of this study was to describe the normative development of sleep at the ages of 3, 6, 8, 12, 18 and 24 months in healthy children., Methods: The present study is based on two birth cohorts that comprise representative samples of families recruited systematically during pregnancy. In the CHILD-SLEEP cohort, the sample sizes were 1427 at three, 1301 at eight, 1163 at 18, and 950 at 24 months. In the Finnbrain cohort, the sample sizes were 2002 at six months and 1693 at 12 months. Healthy term-born children were eligible for this study. To assess the infants' sleep duration and sleep quality, the Brief Infant Sleep Questionnaire was used in both cohorts and additionally the Infant Sleep Questionnaire in the CHILD-SLEEP cohort. The distributions of the study variables were reported using standard parameters., Results: We found that sleep quality is highly variable particularly during the first two years of life, but this variability decreased markedly towards the second year. First, sleep latency decreased by the age of six months, while night-time sleep began to consolidate during the second year. However, parent-reported sleeping problems were common during the entire study period., Conclusion: As many families struggle with infants' sleeping problems, the reference values reported in this article can be valuable tools in various clinical settings to define clinically significant deviances in the sleep development and to identify individuals benefitting from counselling and clinical interventions., (Copyright © 2020 Elsevier B.V. All rights reserved.)

This systematic review focuses on three themes: 1) the nature of pre-sleep cognitive activity in good sleepers and individuals with insomnia, 2) the links between measures of pre-sleep cognitive activity and sleep onset latency (SOL) or insomnia, and 3) the effect of manipulating pre-sleep cognitive activity on SOL or insomnia. Regarding the first theme, mentation reports have been collected in a sleep laboratory, with an ambulatory monitoring device, or using a voice-activated tape-recorder. Normal transition to sleep is characterized by sensorial imagery, deactivation of higher cognitive processes, and hallucinations. Moreover, pre-sleep thoughts in individuals with insomnia frequently relate to planning or problem-solving, and are more unpleasant than in good sleepers. Regarding the second theme, twelve questionnaires and three interviews were identified. Insomnia is associated with more thoughts interfering with sleep, counterfactual processing, worries, maladaptive thought control strategies, covert monitoring, and cognitive arousal. Regarding the third theme, several strategies have been tested: mental imagery, hypnosis, paradoxical intention, articulatory suppression, ordinary suppression, and distraction. Their effect is either beneficial, negligible, or detrimental. Future research should focus on the mechanisms through which some forms of cognitive activity affect sleep onset latency., Competing Interests: Conflicts of interest Luc P. Beaudoin: Director of CogSci Apps Corp. and owner of CogZest. Both of these Canadian businesses develop products based on his affective/cognitive science research. These include books, software, and training services. Other authors: The authors declare having no conflict of interest., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

We hypothesized that: (a) the presence of microsleep (MS) during a Maintenance Wakefulness Test (MWT) trial may represent a reliable marker of sleepiness in obstructive sleep apnea (OSA) patients; (b) the number of MSs will be higher in sleepy versus non-sleepy patients with a borderline MWT mean sleep latency; and (c) scoring MS during MWT analysis may help physicians to recognize patients with a higher degree of sleepiness. We analysed the MWT data of 112 treatment-naïve OSA patients: 20 with short sleep latency (SL, sleep latency <12.8 min), 43 with borderline latency (BL, sleep latency between 12.8 and 32.6 min) and 49 with normal latency (NL, sleep latency >32.6 min). Microsleep was identified in all SL, in 42 BL and in 18 NL patients, with a median latency of 5.6 min. Accordingly, patients were classified into two subgroups: group A (n = 43) with microsleep latency <5.6 min and group B (n = 69) with microsleep latency >5.6 min when present. The mean sleep latency in the MWT was 14.5 ± 7.5 min in group A and 34.6 ± 7.4 min in group B (p < 0.0001). The number of microsleep episodes during each MWT trial was higher in group A than in group B. Sleep latency survival curves demonstrated different patterns of sleep latency in these groups (log-rank test <0.0001). This finding was confirmed in a Cox proportional hazard analysis: the presence of a mean MS latency <5.6 min is associated with an increasing risk of falling asleep during the MWT (RR, 1.93; 95 CI 1.04-3.6; p = 0.03). We conclude that the detection of microsleep may help in discriminating OSA patients with and without daytime vigilance impairment., (© 2019 European Sleep Research Society.)

Background: A substantial proportion of people using cannabis report using it to improve sleep. Yet, little research exists on the associations between the timing of cannabis use and sleep. This study examines the time elapsed between cannabis use and sleep start time and its association with two of the main indicators of sleep continuity: (1) sleep onset latency (SOL) and (2) number of awakenings (NOA) throughout the night., Methods: Each morning, for 7 consecutive days, daily cannabis users (n = 54) reported on the timing of previous night's cannabis use and sleep indicators on their smartphones. Mixed effects models examined the relations of within- and between-subjects' time elapsed between previous night cannabis use and sleep start time, with (1) SOL and (2) NOA., Results: Within subjects, shorter time elapsed between cannabis use and sleep start time was associated with shorter SOL (β = 0.519, p = 0.010), but not NOA (β = -0.030, p = 0.535). Furthermore, between individuals, the time gap between the previous night cannabis use and sleep start time was not associated with SOL or NOA (p > 0.05)., Conclusions: It is possible that cannabis use proximal to bedtime is associated with shorted sleep onset latency but not nighttime awakenings. Cannabis users should be informed about both the potential sleep aid effects of cannabis and its limitations. Pending further evidence of the effects of cannabis on sleep, cannabis users experiencing sleep problems should be provided with evidence-based alternatives to improve sleep, e.g., pharmacological and behavioral treatments., (Copyright © 2020 Elsevier B.V. All rights reserved.)

The accurate estimation of sleep onset is required for many purposes, including the administration of a behavioural treatment for insomnia called Intensive Sleep Retraining, facilitating power naps, and conducting objective daytime sleepiness tests. Specialised equipment and trained individuals are presently required to administer these applications in the laboratory: a costly and impractical procedure which limits their utility in practice. A wearable device could be used to administer these applications outside the laboratory, increasing accessibility. This systematic review aimed to identify practical wearable devices that accurately estimate sleep onset. The search strategy identified seventy-one articles which compared estimations of sleep onset latency from wearable devices against polysomnography (PSG). Actigraphy devices produced average estimations of sleep onset latency that were often not significantly different from PSG, but there was large inter-individual variability depending on participant characteristics. As expected, electroencephalography-based devices produced more accurate and less variable estimates. Devices that measured behavioural aspects of sleep onset consistently overestimated PSG-determined sleep onset latency, but to a comparatively low degree. This sleep measurement method could be deployed in a simple wearable device to accurately estimate sleep onset and administer Intensive Sleep Retraining, power naps, and objective daytime sleepiness tests outside the laboratory setting., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

A mandibular advancement device (MAD) is recommended as an alternative therapy for obstructive sleep apnea (OSA), which effectively reduces the collapsibility of the upper airway during sleep by advancing the mandible. However, the effects of MAD therapy on cardiac autonomic modulation remain unclear. We evaluated the effects of MAD on nocturnal heart rate variability (HRV) in OSA. Anthropometric data, questionnaire results, and HRV parameters (evaluated using time domain and frequency domain methods) of 58 adult patients with OSA treated with MAD therapy were retrospectively reviewed. All patients underwent polysomnography at baseline and 3-month follow-up. The average normal-to-normal (NN) interval, standard deviation of the NN interval, low-frequency power in normalized units (LFnu), and high-frequency power in normalized units (HFnu) showed significant changes with MAD therapy. Based on the criteria for success (decrease in the apnea-hypopnea index by >50% and value <20/h), 34 and 24 patients were classified into the response and nonresponse groups, respectively. No differences in baseline characteristics were detected between groups, except for higher body mass index and lower minimal oxygen saturation in the nonresponse group. A subgroup analysis indicated that the average NN interval and HFnu significantly increased, and that Total power (TP), very low frequency, low frequency(LF), low frequency/high frequency and LFnu significantly decreased compared to baseline in the response group; however, no HRV changes were found in the nonresponse group. After adjusting for age, sex, and body mass index, the response group showed significant changes from baseline in TP and LF compared to the nonresponse group. Therefore, HRV may be useful for determining the efficacy of MAD therapy in OSA.

Study Objectives: The wake-sleep transition zone represents a poorly defined borderland, containing, for example, microsleep episodes (MSEs), which are of potential relevance for diagnosis and may have consequences while driving. Yet, the scoring guidelines of the American Academy of Sleep Medicine (AASM) completely neglect it. We aimed to explore the borderland between wakefulness and sleep by developing the Bern continuous and high-resolution wake-sleep (BERN) criteria for visual scoring, focusing on MSEs visible in the electroencephalography (EEG), as opposed to purely behavior- or performance-defined MSEs., Methods: Maintenance of Wakefulness Test (MWT) trials of 76 randomly selected patients were retrospectively scored according to both the AASM and the newly developed BERN scoring criteria. The visual scoring was compared with spectral analysis of the EEG. The quantitative EEG analysis enabled a reliable objectification of the visually scored MSEs. For less distinct episodes within the borderland, either ambiguous or no quantitative patterns were found., Results: As expected, the latency to the first MSE was significantly shorter in comparison to the sleep latency, defined according to the AASM criteria. In certain cases, a large difference between the two latencies was observed and a substantial number of MSEs occurred between the first MSE and sleep. Series of MSEs were more frequent in patients with shorter sleep latencies, while isolated MSEs were more frequent in patients who did not reach sleep., Conclusion: The BERN criteria extend the AASM criteria and represent a valuable tool for in-depth analysis of the wake-sleep transition zone, particularly important in the MWT., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Study Objectives: Poor sleep patterns in older adults are associated with chromosomal telomere shortening, a marker of cellular senescence. However, studies have relied on self-reported sleep characteristics, with few data for younger individuals. We investigated whether sleep measured via actigraphy was cross-sectionally associated with telomere length in children and midlife adults., Methods: A population-based sample of 1874 11-12 year olds and midlife adults (mean age 44 years, SD 5.1) had biological and physical assessments at centers across Australia in 2015-2016. Sleep characteristics, including duration, onset, offset, day-to-day variability, and efficiency, were derived from actigraphy. Relative telomere length (T/S ratio) was measured by quantitative polymerase chain reaction on genomic DNA from peripheral blood. Multivariable regression models estimated associations, adjusting for prespecified confounders., Results: Both sleep and telomere data were available for 728 children and 1070 adults. Mean (SD) T/S ratio was 1.09 (0.55) in children and 0.81 (0.38) in adults. T/S ratio was not predicted by sleep duration (β 0.04, 95% confidence interval [CI] -0.02 to 0.09, p = .16, children; β -0.004, 95% CI -0.03 to 0.02, p = .70, adults) or most other sleep metrics. The only exception was a weak association between later sleep timing (the midpoint of sleep onset and offset) and longer telomeres in adults (β 0.03, 95% CI 0.01 to 0.06, p = .01)., Conclusions: Objective sleep characteristics show no convincing associations with telomere length in two largely healthy populations up to at least midlife. Sleep-telomere associations may be a late-life occurrence or may present only with a trigger such as presence of other morbidities., (© Sleep Research Society 2019. Published by Oxford University Press [on behalf of the Sleep Research Society]. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

Study Objectives: We hypothesized that sleep stage dynamics are different in patients with sleep bruxism (SB) and that these changes are associated with the occurrence of rhythmic masticatory muscle activity (RMMA)., Methods: Fifteen healthy controls and 15 patients with SB underwent overnight polysomnography. Sleep variables and survival curves of continuous runs of each sleep stage were compared between the groups. Stage transition dynamics and the probability of stage fragmentation were analyzed for three epochs before and after the epoch with RMMA. Survival curves of continuous runs of each sleep stage, terminated with or without RMMA, were also compared., Results: There were no significant differences in sleep variables between the groups, except for shorter sleep latency, shorter rapid eye movement (REM) latency, and longer total N1 duration in SB patients than in controls. REM sleep and N2 were significantly less continuous in SB patients than in controls. In the SB group, stage fragmentation probability was significantly increased for the epoch with RMMA compared with the baseline for all stages. Meanwhile, the occurrence of RMMA did not affect the continuity of N2 or REM; however, the occurrence of RMMA was preceded by more continuous N3 runs., Conclusions: Sleep stage dynamics differed between SB patients and controls. RMMA does not result in sleep disruption but is likely associated with dissipation of sleep pressure. Less continuity of REM sleep in SB may provide insights into the underlying pathophysiological mechanisms of SB, which may be related to REM sleep processes such as cortical desynchronized states or brainstem activation., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Objective: Pain is common among women with gynecologic cancer and contributes to depressed mood, sleep disturbances, and likelihood of future chronic pain. Little is known about how psychosocial factors are associated with central sensitization of pain in gynecologic cancer. This study examined relations among depressive symptoms, sleep, subjective pain, and aftersensation pain (a proxy for central sensitization of pain) in gynecologic cancer., Methods: Participants were 42 women (mean age [SD] = 59.60 [10.11] years) enrolled in a randomized clinical trial examining psychological intervention effects on sleep, pain, mood, and stress hormones/cytokines in gynecologic cancer. Six to eight weeks after surgery, participants completed an assessment of depressive symptoms, sleep, and subjective pain and a temporal summation of pain protocol via quantitative sensory testing (QST)., Results: Controlling for recent chemotherapy, history of chronic pain, and analgesic medication use, regression analyses revealed that longer sleep onset latency (SOL; B = 3.112, P = 0.039, bias-corrected and accelerated (BCa) 95% confidence interval [CI] = 0.371 to 6.014) and greater sensory pain (B = 0.695, P = 0.023, BCa 95% CI = 0.085 to 1.210) were associated with greater aftersensation pain at 15 seconds. Greater sensory pain scores were associated with greater aftersensation pain at 30 seconds (B = 0.286, P = 0.045, BCa 95% CI = 0.008 to 0.513). Depression was not associated with aftersensation pain. The overall models accounted for 44.5% and 40.4% of the variance in aftersensation pain at 15 and 30 seconds, respectively. Conclusions. Longer SOL and higher subjective sensory pain were related to greater aftersensation of experimentally induced pain in women postsurgery for gynecologic cancers. Interventions that improve sleep and subjective sensory pain during the perisurgical period may reduce risk for central sensitization of pain., (© 2018 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

The aim of this study was to evaluate the effects of sleep hygiene (SH) education on sleep quality in soccer players after a late-evening small-sided-game (SSG) training session. Twenty-nine non-professional players were recruited and allocated to either an experimental group (EG, n = 17) that received SH education, or a control group (CG, n = 12). SSG consisted of 3 × 4 min in a 4vs4, with 3 min of recovery and was performed at 8.00 p.m. Sleep quality was monitored via actigraphy and sleep diary entries before (PRE) and two nights after (POST1, POST2) the SSG. Sleep latency (SL) differed between the two groups at POST1 (4.9 ± 5.4 vs. 15.5 ± 16.1 for EG and CG, respectively; p = 0.017, effect size [ES] = 2.0); SL values were lower at POST1 compared to PRE for the EG (-47%; p = 0.021, ES = 0.6). Subjective sleep quality was better in the EG than the CG at POST1 (8.6 ± 1.0 vs. 7.1 ± 2.0 for EG and CG, respectively; p = 0.016, ES = 0.9) with a significant improvement over PRE-values (+11.0%, p = 0.004, ES = 0.8). Although SL and subjective sleep quality did not decrease significantly from POST1 to POST2 values at POST2 no longer differed significantly form baseline and, hence, indicate that observed effects may be short-lasting. No other objective sleep indices were influenced by late-evening training or SH practices implemented by the EG. Soccer players may benefit from acute SH strategies to reduce the time to sleep onset after late-evening training sessions.

Objective/background: Prospective, daily sleep diaries are the gold standard for assessing subjective sleep but are not always feasible for cross-sectional or epidemiological studies. The current study examined psychometric properties of two retrospective questionnaire versions of the Consensus Sleep Diary., Participants/methods: College students (N = 131, mean age = 19.39 ± 1.65; 73% female) completed seven days of prospective sleep diaries then were randomly assigned to complete either the Self-Assessment of Sleep Survey (SASS), which assessed past week sleep (n = 70), or the SASS-Split (SASS-Y), which assessed weekday/weekend sleep separately (n = 61). Participants also completed psychosocial/sleep questionnaires including the Pittsburgh Sleep Quality Index (PSQI). Sleep parameters derived from SASS, SASS-Y, PSQI, and sleep diaries were assessed via Bland Altman plots, limits of agreement, mean differences, and correlations., Results: SASS-Y demonstrated stronger correlations with prospective sleep diaries and slightly less biased estimates (r = 0.51 to 0.85, α = -0.43 to 1.70) compared to SASS (r = 0.29 to 0.84, α = -1.63 to 2.33) for terminal wakefulness (TWAK), sleep onset latency (SOL), sleep efficiency (SE), and quality (QUAL). SASS resulted in slightly less bias for total sleep time (TST) and wake after sleep onset (WASO) (α = -0.65 and 0.93, respectively) compared to SASS-Y (α = 14.90 and 1.05, respectively). SASS and SASS-Y demonstrated greater convergence with sleep diary than PSQI., Conclusions: Results demonstrated good psychometric properties for the SASS and SASS-Y. When prospective sleep diaries are not feasible, the SASS and SASS-Y are acceptable substitutes to retrospectively estimate sleep parameters. Retrospective estimation of sleep parameters separately for weekdays/weekends may offer advantages compared to whole week estimation., (Copyright © 2019. Published by Elsevier B.V.)

Nédélec, M, Leduc, C, Dawson, B, Guilhem, G, and Dupont, G. Case study: sleep and injury in elite soccer. A mixed method approach. J Strength Cond Res 33(11): 3085-3091, 2019-This case study allowed an examination of the link between sleep and injury occurrence in an elite male soccer player competing in French League 1 and Union of European Football Associations matches. During 4 months, a mixed method approach was used, combining actigraphic sleep assessment with qualitative interviews on a daily basis. Three injuries were reported over the study period. Sleep onset latency (SOL), both in the single night (117 ± 43 minutes) and in the week (78 ± 50 minutes) before injury occurrence, was longer than preseason baseline values (18 ± 13 minutes; effect size (ES): 3.1 and 1.6, respectively). Similarly, sleep efficiency in the single night (73 ± 7%) and the week (75 ± 7%) before injury occurrence was lower than baseline (90 ± 3%; ES: 3.2 and 2.8, respectively). In this case study, SOL and efficiency were altered on the night and in the week before injury occurrence. Individualized assessment of sleep during congested playing schedules may be useful to aid in preventing injury occurrence.

Study Objectives: Children with craniopharyngioma are at risk for excessive daytime sleepiness (EDS). Multiple Sleep Latency Testing (MSLT) is the gold standard for objective evaluation of EDS; however, it is time and resource intensive. We compared the reliability, sensitivity, and specificity of the modified Epworth Sleepiness Scale (M-ESS) and MSLT in monitoring EDS in children with craniopharyngioma., Methods: Seventy patients (ages 6 to 20 years) with craniopharyngioma completed the M-ESS and were evaluated by polysomnography and MSLT. Evaluations were made after surgery, if performed, and before proton therapy., Results: MSLT revealed that 66 participants (81.8%) had EDS, as defined by a mean sleep latency (MSL) < 10 minutes, with only 28.8% reporting EDS on the M-ESS by using a cutoff score of 10. The M-ESS demonstrated adequate internal consistency and specificity (91.7%) but poor sensitivity (33.3%) with the established cutoff score of 10. A cutoff score of 6 improved the sensitivity to 64.8% but decreased the specificity to 66.7%., Conclusions: Patients with craniopharyngioma are at high risk for EDS, as documented objectively on the MSLT, but they frequently do not recognize or accurately report their sleepiness. Future sleep studies should investigate whether specific items or alternative self- and parent-reported measures of sleepiness may have greater clinical utility in monitoring sleepiness in this population., (© 2019 American Academy of Sleep Medicine.)

Study Objectives: Disturbed overnight sleep is a prominent feature of advanced stage Huntington's disease (HD). Several polysomnography (PSG) studies have reported significant changes of sleep in HD patients, but the findings are not unequivocal. To date, no meta-analysis has investigated the PSG changes in HD patients. The present study meta-analyzed results from studies examining the PSG changes in HD patients compared with controls., Methods: A literature search performed in MEDLINE, EMBASE, All EBM databases, PsycINFO, and CINAHL databases identified seven studies involving 152 HD patients and 144 controls which were included in our meta-analysis., Results: Pooled results indicated decreased sleep efficiency, percentage of slow wave sleep and rapid eye movement sleep, and increased percentage of N1 sleep, wake time after sleep onset, and rapid eye movement sleep latency in HD patients compared with controls. We found high heterogeneity in the effect sizes and no indication of systematic publication biases across studies. Meta-regression analyses showed that some of the heterogeneity was explained by age, body mass index (BMI), CAG repeat length, and disease severity of HD patients., Conclusions: Our study showed that polysomnographic abnormalities are present in HD. Our findings also underscore the need for a comprehensive PSG assessment of sleep changes in patients with HD. Furthermore, the effects of age, BMI and CAG repeat length on sleep changes should be carefully considered and closely monitored in the management of HD., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Objective: To validate polysomnographic markers (sleep latency and sleep-onset REM periods [SOREMPs] at the Multiple Sleep Latency Test [MSLT] and nocturnal polysomnography [PSG]) for pediatric narcolepsy type 1 (NT1) against CSF hypocretin-1 (hcrt-1) deficiency and presence of cataplexy, as no criteria are currently validated in children., Methods: Clinical, neurophysiologic, and, when available, biological data (HLA-DQB1*06:02 positivity, CSF hcrt-1 levels) of 357 consecutive children below 18 years of age evaluated for suspected narcolepsy were collected. Best MSLT cutoffs were obtained by receiver operating characteristic (ROC) curve analysis by contrasting among patients with available CSF hcrt-1 assay (n = 228) with vs without CSF hcrt-1 deficiency, and further validated in patients without available CSF hcrt-1 against cataplexy (n = 129)., Results: Patients with CSF hcrt-1 deficiency were best recognized using a mean MSLT sleep latency ≤8.2 minutes (area under the ROC curve of 0.985), or by at least 2 SOREMPs at the MSLT (area under the ROC curve of 0.975), or the combined PSG + MSLT (area under the ROC curve of 0.977). Although specificity and sensitivity of referenc e MSLT sleep latency ≤8 minutes and ≥2 SOREMPs (nocturnal SOREMP included) was 100% and 94.87%, the combination of MSLT sleep latency and SOREMP counts did not improve diagnostic accuracy. Age or sex also did not significantly influence these results in our pediatric population., Conclusions: At least 2 SOREMPs or a mean sleep latency ≤8.2 minutes at the MSLT are valid and reliable markers for pediatric NT1 diagnosis, a result contrasting with adult NT1 criteria., Classification of Evidence: This study provides Class III evidence that for children with suspected narcolepsy, polysomnographic and MSLT markers accurately identify those with narcolepsy type 1., (© 2019 American Academy of Neurology.)

The use of screen electronic devices in the evening negatively affects sleep. Yet, sleep is known to be essential for brain maturation and a key factor for good academic performance, and thus is particularly critical during childhood and adolescence. Although previous studies reported associations between screen time and sleep impairment, their causal relationship in adolescents remains unclear. Using actigraphy and daily questionnaires in a large sample of students (12 to 19 years old), we assessed screen time in the evening and sleep habits over 1 month. This included a 2 week baseline phase, followed by a 40 min sleep education workshop and a 2 week interventional phase, in which participants were asked to stop using screen devices after 9 pm during school nights. During the interventional phase, we found that the reduction of screen time after 9 pm correlated with earlier sleep onset time and increased total sleep duration. The latter led to improved daytime vigilance. These findings provide evidence that restricting screen use in the evening represents a valid and promising approach for improving sleep duration in adolescents, with potential implications for daytime functioning and health., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Falling asleep is a gradually unfolding process. We investigated the role of various oscillatory activities including sleep spindles and alpha and delta oscillations at sleep onset (SO) by automatically detecting oscillatory events. We used two datasets of healthy young males, eight with four baseline recordings, and eight with a baseline and recovery sleep after 40 h of sustained wakefulness. We analyzed the 2-min interval before SO (stage 2) and the five consecutive 2-min intervals after SO. The incidence of delta/theta events reached its maximum in the first 2-min episode after SO, while the frequency of them was continuously decreasing from stage 1 onwards, continuing over SO and further into deeper sleep. Interestingly, this decrease of the frequencies of the oscillations were not affected by increased sleep pressure, in contrast to the incidence which increased. We observed an increasing number of alpha events after SO, predominantly frontally, with their prevalence varying strongly across individuals. Sleep spindles started to occur after SO, with first an increasing then a decreasing incidence and a continuous decrease in their frequency. Again, the frequency of the spindles was not altered after sleep deprivation. Oscillatory events revealed derivation dependent aspects. However, these regional aspects were not specific of the process of SO but rather reflect a general sleep related phenomenon. No individual traits of SO features (incidence and frequency of oscillations) and their dynamics were observed. Delta/theta events are important features for the analysis of SO in addition to slow waves., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

Water-based passive body heating (PBH WB ) as a warm shower or bath before bedtime is often recommended as a simple means of improving sleep. We searched PubMed, CINAHL, Cochran, Medline, PsycInfo, and Web of Science databases and extracted pertinent information from publications meeting predefined inclusion and exclusion criteria to explore the effects of PBH WB on sleep onset latency (SOL), wake after sleep onset, total sleep time, sleep efficiency (SE), slow wave sleep, and subjective sleep quality. The search yielded 5322 candidate articles of which 17 satisfied inclusion criteria after removing duplicates, with 13 providing comparable quantitative data for meta-analyses. PBH WB of 40-42.5 °C was associated with both improved self-rated sleep quality and SE, and when scheduled 1-2 h before bedtime for little as 10 min significant shortening of SOL. These findings are consistent with the mechanism of PBH WB effects being the extent of core body temperature decline achieved by increased blood perfusion to the palms and soles that augments the distal-to-proximal skin temperature gradient to enhance body heat dissipation. Nonetheless, additional investigation is required because the findings regarding PBH WB are limited by the relative scarcity of reported research, especially its optimal timing and duration plus exact mechanisms of effects., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: In recent years, short sleep has been increasingly recognized as a risk factor for obesity. However, current evidence has so far been limited to cross-sectional studies or longitudinal studies using self-reported sleep. Therefore, we explored the directionality of the association between objectively measured sleep and body mass index (BMI)., Methods: The study consists of 1031 participants from the general population (52% women, 45-91 years at baseline). Sleep, BMI and waist circumference (WC) were measured twice across a follow-up of six years. BMI and WC were measured at the research center. Total sleep time (TST, hrs), sleep onset latency (SOL, min), sleep efficiency (SE, %) and wake after sleep onset (WASO, min) were estimated by a wrist-worn actigraph. In addition, cross-sectional and longitudinal associations in both directions were explored., Results: An hour shorter TST was cross-sectionally associated with approximately 0.5 kg/m 2 higher BMI. Longitudinally, longer TST and higher SE were associated with lower BMI (β TST  = -0.75, 95% CI: -1.08, -0.42; β SE  = -0.04, 95% CI: -0.08, -0.01). Conversely, one kg/m 2 higher BMI was prospectively associated with 0.02 h shorter TST (95% CI: -0.03, -0.01), and this association was more pronounced over time. Results from analyses with WC were in line with those of BMI., Conclusions: This is the first study to explore bidirectionality in the association between objectively measured sleep and BMI in a large population of middle-aged and older adults. Indices of poor sleep were associated with higher and less stable BMI across time. Conversely, a high BMI was associated with a decrease in sleep duration. This confirms that the relation between sleep and body size is bidirectional, and changes in either sleep or BMI are likely to co-occur with changes in health through multiple pathways., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Objective/background: Rates of suicide attempts in Canadian youths are concerning. Adolescence is a sensitive period for the emergence of both sleep and mood problems, two major risk factors for suicidality. This naturalistic study aimed to define the sleep profile of adolescents under the combined influence of suicidality, depression and pharmacotherapy during hospitalization for a suicidal crisis., Patients/methods: Seventeen suicidal adolescents (15.0 + 1.2years, 82% females) with major depression were recruited from a Canadian pedopsychiatric inpatient unit. Seventeen non-depressed adolescents were retrospectively collated from another database (15.0 + 1.1years, 83% females). None of the participants had a history of sleep disorders or significant medical conditions., Results: Compared to controls, suicidal adolescents had a longer sleep onset latency (Z = -4.5, p < 0.001), longer REM latency (Z = -3.2, p = 0.001), higher percentage of NREM1 sleep t(33) = -2.6, p = 0.020), and higher REM density (Z = -2.8, p = 0.004) than controls. Higher REM density correlated with higher CDI-II scores (r = 0.55, p = 0.27) A significant interaction indicated that the two groups had similar NREM3 percentages in the first two-thirds of the night, but that the suicidal group had significantly lower NREM3 percentage than the controls in the last third of the night (F(2,66) = 3.4, p = 0.041)., Conclusions: Significant sleep abnormalities were observed during hospitalization for a suicidal crisis in a sample of depressed and mostly medicated adolescents. This included sleep initiation and REM sleep latency abnormalities, shallower sleep and high REM density. Future studies should decipher the relative effects of depression, suicidality and medication on sleep. These findings stress the need to address sleep disturbances in the management of suicidality in adolescents., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Study Objectives: The main objective of the study was to assess the prevalence, the severity, and the daytime course of excessive daytime sleepiness (EDS) in advanced Parkinson's disease (PD) and to explore how people with PD perceive the degree and onset of their sleepiness during objective sleepiness tests. In addition, the occurrence of early-onset rapid eye movement (REM) periods (sleep-onset REM periods [SOREMPs]) in PD was assessed., Methods: We analyzed data from 46 people with PD (26 males, mean age 63.5 years, mean UPDRS-III-OFF 34.7). The sleep-wake assessment included Epworth sleepiness scale (ESS), Karolinska sleepiness scale (KSS), and objective (polysomnography, multiple sleep latency test [MSLT], and maintenance of wakefulness tests [MWT]) measures., Results: Subjective (ESS ≥ 10) and objective (mean sleep latency, MSL < 5 min in MSLT) EDS were present in 43% and 41% of patients, respectively. The MSL in MSLT and MWT remained unchanged throughout the day and significantly correlated with KSS during the trial but not with KSS shortly before it. In MWT, about one-fourth of patients failed to signal their sleepiness before falling asleep. SOREMPs, usually (83%) arising from NREM1 or wake, were recorded in 24% of the patients. People with SOREMPs had significantly lower MSL in MSLT and MWT and higher AHI compared with those without SOREMPs., Conclusions: Patients with PD exhibit daylong increased EDS but they underestimate its degree and often fail to signal its onset. SOREMPs in PD have a "narcoleptic" character in sleep-stage sequencing and are associated with the presence of sleep-disturbed breathing. These results add to our understanding of sleepiness and sleepiness perception in PD and have important implications for its diagnosis and management., (© Sleep Research Society 2019. Published by Oxford University Press on behalf of the Sleep Research Society. All rights reserved. For permissions, please e-mail journals.permissions@oup.com.)

We examined associations between self-reported sleep measures and cognitive level and change (age 70-76 years) in a longitudinal, same-year-of-birth cohort study (baseline N = 1091; longitudinal N = 664). We also leveraged GWAS summary data to ascertain whether polygenic scores (PGS) of chronotype and sleep duration related to self-reported sleep, and to cognitive level and change. Shorter sleep latency was associated with significantly higher levels of visuospatial ability, processing speed, and verbal memory (β ≥ |0.184|, SE ≤ 0.075, p ≤ 0.003). Longer daytime sleep duration was significantly associated slower processing speed (β = -0.085, SE = 0.027, p = 0.001), and with steeper 6-year decline in visuospatial reasoning (β = -0.009, SE = 0.003, p = 0.008), and processing speed (β = -0.009, SE = 0.002, p < 0.001). Only longitudinal associations between longer daytime sleeping and steeper cognitive declines survived correction for important health covariates and false discovery rate (FDR). PGS of chronotype and sleep duration were nominally associated with specific self-reported sleep characteristics for most SNP thresholds (standardized β range = |0.123 to 0.082|, p range = 0.003 to 0.046), but neither PGS predicted cognitive level or change following FDR. Daytime sleep duration is a potentially important correlate of cognitive decline in visuospatial reasoning and processing speed in older age, whereas cross-sectional associations are partially confounded by important health factors. A genetic propensity toward morningness and sleep duration were weakly, but consistently, related to self-reported sleep characteristics, and did not relate to cognitive level or change., (© Sleep Research Society 2019. Published by Oxford University Press [on behalf of the Sleep Research Society].)

Depression, anxiety, sleep disturbances and poor relationship functioning often co-occur with the confluence of these factors contributing to greater suicide risk. This study investigated whether the pathways between depression, anxiety, sleep disturbances, and relationship functioning differentiated patients with suicide attempt history from those with suicidal ideation history. Patients seeking partial hospital treatment for severe psychiatric symptoms (N = 180) completed interviews assessing psychiatric and suicidal symptom histories, and self-report measures of sleep behaviors, anxiety, depression, and relationship functioning. Multiple sleep behaviors were examined: duration, sleep onset latency, and bedtime. Bias-corrected bootstrap mediation and moderated mediation analyses with suicide attempt as the moderator were used to evaluate pathways between variables. Among patients with ideation and attempt history, (1) sleep onset latency significantly mediated the association between depression and relationship functioning and that between anxiety and relationship functioning; (2) relationship functioning significantly mediated the association between depression and sleep onset latency and that between anxiety and sleep onset latency. These pathways were not significant among patients with suicidal ideation only. No other sleep behaviors were related to study variables. The reciprocal relationship between disrupted sleep onset latency and poor relationship functioning was specifically linked to more severe psychiatric symptoms among acute patients with suicide attempt histories., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Objective: The purpose of this study was to enhance our understanding of clinical trends in sleep and rapid eye movement (REM) propensity on the multiple sleep latency test (MSLT). Demographic variables of interest included early childhood/advanced age, gender, race, and REM-suppressant use., Methods: Nocturnal sleep studies and 5-nap MSLTs were retrieved from a large repository of deidentified studies from various US sleep clinics between 2007 and 2015. Studies were signal processed, human-edited, and underwent rigorous quality assurance for inclusion., Results: The final sample consisted of N = 2498 MSLTs (24.2% Black; 34.2% Men; Age 4-89). In adults (age ≥ 21), sleep propensity modestly decreased across nap (90% at nap 1 to 80% at nap 5; p < 0.001). Children ≤12 years were least likely to fall asleep on any nap (∼55% at nap 5). REM propensity troughed at nap 4 (13%) and varied with age. Advanced age (≥60 years; OR: 0.28, p < 0.001), REM-suppressant use (OR:0.52, p < 0.001), and female sex (men OR: 1.48, p = 0.012) was associated with a decreased proportion of ≥2 REMs in adjusted logistic models. Children often demonstrated only 1 REM and generally had long sleep latencies, yielding a low proportion of MSLTs consistent with narcolepsy (11.0% vs. 19.2% and 16.8% in those between 13-20 and 21-59, respectively; p = 0.003)., Conclusions: MSLT outcomes vary greatly across age, gender, and use of psychotropic medication. Demographic variance should be considered when interpreting MSLT results. Robust age effect question the appropriateness of the MSLT as currently designed and implemented for children and older adults., (Copyright © 2018 Elsevier B.V. All rights reserved.)