Nighttime Sleep Period Research Articles

OFF-times before, during, and after nighttime sleep periods in Parkinson's disease patients with motor fluctuations and the effects of opicapone: A post hoc analysis of diary data from BIPARK-1 and -2

IntroductionIn BIPARK-1 and BIPARK-2, addition of once-daily opicapone to levodopa/carbidopa significantly reduced daily “OFF”-time relative to placebo in adults with Parkinson's disease (PD) and motor fluctuations. Diary data from these studies were pooled and analyzed post hoc to characterize “OFF”-times around nighttime sleep and to explore the effects of opicapone 50 mg. Methods“OFF” before sleep (OBS), “OFF during the nighttime sleep period” (ODNSP), early morning “OFF” (EMO), and duration of nighttime sleep and awake periods were analyzed descriptively at baseline. Mean changes from baseline to Week 14/15 (end of double-blind treatment) were analyzed using two-sided t-tests in participants with data for both visits. ResultsAt baseline, 88.3 % (454/514) of participants reported having OBS (34.0 %), ODNSP (17.1 %), or EMO (79.6 %). Those with ODNSP had substantially shorter mean duration of uninterrupted sleep (4.4 h) than the overall pooled population (7.1 h). At Week 14/15, mean decrease from baseline in ODNSP duration was significantly greater with opicapone than with placebo (−0.9 vs. −0.4 h, P < 0.05). In participants with ODNSP at baseline, the decrease in total time spent awake during the night-time sleep period was significantly greater with opicapone than with placebo (−1.0 vs. −0.4 h, P < 0.05), as was the reduction in percent time spent awake during the night-time sleep period (−12.8 % vs. −4.5 %, P < 0.05). Conclusion“OFF”-times around nighttime sleep were common in BIPARK-1 and BIPARK-2. Opicapone may improve sleep by decreasing the amount of time spent awake during the night in patients with PD who have night-time sleep period “OFF” episodes.

P052 Is Circadian Adaptation to Night Work Affected by the Intensity of Ambient Lighting?

Abstract Introduction The aim of this study was to examine whether the intensity of ambient lighting affects the rate at which the human circadian system adapts to working at night. Methods. The whole study will include 60 participants (50:50, F:M; aged 28–35yr; good sleep/health) randomised to one of three conditions. In each condition, participants work 14 x 12-hr simulated night shifts (19:00–07:00h) while living 24h/day in an accommodation suite. The only difference between conditions is in the light intensity during night shifts – dim (5–10lx), moderate (50–100lx), normal (300–350lx). Circadian adaptation is being assessed using the hourly rate of 6-sulphatoxymelatonin (aMT6s) production during sleep. Results The project is in progress, so these results are for the first 6–12 participants in each condition. For each day, circadian adaptation is assessed by expressing the rate of aMT6s excreted during the daytime sleep period as a percentage of the rate of aMT6s excreted during the night-time baseline sleep period (for an adaption score of 0–100%). On average, participants in the dim condition are adapted by 26%,37%,32% after nights 1,7,14; participants in the moderate condition are adapted by 23%,37%,60% after nights 1,7,14; and participants in the normal condition are adapted by 27%,117%,103% after nights 1,7,14. Discussion These data indicate that the rate, and degree, of circadian adaptation to night work is substantially affected by the intensity of ambient lighting. Therefore, lighting conditions should be incorporated into OHS guidelines related to managing the fatigue risks associated with night work.

Sleep Duration and Kindergarten Adjustment.

The current study examined longitudinal linkages between child sleep duration and children's socioemotional, learning engagement, executive functioning, and academic outcomes across the full kindergarten (K) year. A measurement-burst design was employed to examine 3 different measures of child sleep duration in 7-day bursts at pre-K (July-August), early K (late September), mid-K (late November), and late K (mid-to-late April), using wrist actigraphy. These measures included mean amounts of child sleep per 24-hour period across the full week, proportion of 24-hour periods per week that children slept 10 or more hours, and proportion of nighttime sleep periods per week that children slept 10 or more hours. Children's outcomes at early, mid-, and late K were provided by their K teachers blind to children's sleep histories, and by assessments administered by project staff. Among the 3 sleep measures examined, regularity of nighttime sleep in which children slept 10 or more hours per night, especially at pre-K, consistently predicted more favorable K outcomes in both socioemotional, learning engagement, and academic domains. Results suggested that establishing healthy nighttime sleep habits before K start was especially promotive of better K adjustment across the full K year. These findings were controlled for income-to-poverty threshold ratios, child health status, and number of missed school days. Efforts to promote a favorable transition to first-time schooling should pay particular attention to sleep hygiene and regularity of 10-plus hours of nightly child sleep established before the start of K.

Associations of sleep-related behaviors and the sleep environment at infant age one month with sleep patterns in infants five months later

ObjectiveTo characterize family and environmental correlates of sleep patterns that may contribute to differences in infant sleep. MethodsWe studied 313 infants in the Rise & SHINE (Sleep Health in Infancy & Early Childhood study) cohort. Our main exposures were the parent-reported sleep environment, feeding method and sleep parenting strategies at infant age one month. The main outcomes were nighttime sleep duration, longest nighttime sleep and number of awakenings measured by actigraphy at age six months. We used multivariable linear regression models to examine associations, and secondarily also explored the role of sleep-related environmental exposures in mediating previously observed associations of racial/ethnicity and parental education with infant sleep characteristics. ResultsIn adjusted models, a non-dark sleep environment (versus an always dark sleep location) and taking the baby to parent's bed when awake at night (versus no co-sleeping) were associated with 28 (95% CI, −45, −11) and 18 (95% CI, −33, −4) minutes less sleep at night, respectively. Bottle feeding at bedtime was associated with 62 (95% CI, 21, 103) minutes additional longest nighttime sleep period. Exploratory mediation analyses suggested a modest mediating role of a non-dark sleep environment on racial/ethnic and educational differences in sleep duration. ConclusionsInfant sleep duration was positively associated with a dark sleep environment and a focal feed at bedtime while taking the baby to the parent's bed was associated with reduced infant sleep. Modifying the sleep environment and practices may improve infant sleep and reduce sleep health disparities.

The Importance of Terminology for Quantifying Nocturia in Practice

BackgroundAlthough nocturia, affecting mainly the elderly population, is a urinary tract symptom, it may also be a part of conditions not related to the urinary tract. In this scenario, nocturia terminology is crucial to avoid confusion and misunderstanding across different specialities. The International Continence Society (ICS) provides the updated nocturia terminology. ObjectiveTo review, describe, and explain the applicability of nocturia terminology based on the ICS standardisation documents. Design, setting, and participantsThe ICS report provides definitions on the terminology for nocturia and nocturnal lower urinary tract function, which were identified and summarised. Outcome measurements and statistical analysisTerminology was classified as symptoms and signs, and an explanation of how terms are applied in a bladder diary for use in clinical practice was given. Results and limitationsTerminology was classified into symptoms and signs. Nocturia is a symptom where the patient reports waking up to pass urine during their main sleep period, and every episode is followed by sleep or the intention to sleep. Nocturnal polyuria is a symptom when the patient perceives that they have passed large volumes of urine during the main sleep period. Enuresis is the complaint of incontinence that occurs while a patient is asleep and is usually unaware of it. All these terms can be a sign when quantified on the bladder diary. The remaining terminology is identified and quantified on the 3-d bladder diary (24-h voided volume, 24-h polyuria, nocturnal urine volume, night-time frequency, first morning void, night-time main sleep period). ConclusionsThe health care provider must understand the critical differences between the different terms. It will facilitate communication among all the professionals involved in the care of these patients. A 3-d bladder diary is a fundamental tool for assessing nocturia. Patient summaryThis paper has the objective of defining and explaining all the terms currently used for nocturia. For this purpose, we utilised the published standard terminology and summarised it with examples for better understanding and applicability.

To Nap or Not to Nap? A Systematic Review Evaluating Napping Behavior in Athletes and the Impact on Various Measures of Athletic Performance

PurposeThe objective of this systematic review was to 1) determine how studies evaluated napping behavior in athletes (frequency, duration, timing and measurement); 2) explore how napping impacted physical performance, cognitive performance, perceptual measures (eg, fatigue, muscle soreness, sleepiness and alertness), psychological state and night-time sleep in athletes.MethodsFive bibliographic databases were searched from database inception to 11 August 2020. Observational and experimental studies comprising able-bodied athletes (mean age ≥12 years), published in English, in peer-reviewed journal papers were included. The Downs and Black Quality Assessment Checklist was used for quality appraisal.ResultsThirty-seven studies were identified of moderate quality. Most studies did not include consistent information regarding nap frequency, duration, and timing. Napping may be beneficial for a range of outcomes that benefit athletes (eg, physical and cognitive performance, perceptual measures, psychological state and night-time sleep). In addition, napping presents athletes with the opportunity to supplement their night-time sleep without compromising sleep quality.ConclusionAthletes may consider napping between 20 to 90 min in duration and between 13:00 and 16:00 hours. Finally, athletes should allow 30 min to reduce sleep inertia prior to training or competition to obtain better performance outcomes. Future studies should include comprehensive recordings of nap duration and quality, and consider using sleep over a 24 hour period (daytime naps and night-time sleep period), specifically using objective methods of sleep assessment (eg, polysomnography/actigraphy).

The effects of infant behavioural sleep interventions on maternal sleep and mood, and infant sleep: A randomised controlled trial.

Infant sleep problems are one of the first challenges for parents, negatively influencing infants and mothers. The present study examined the effects of preventive behavioural sleep intervention (BSI) on infant sleep patterns, maternal sleep quality, and depression. A clinical randomised multicentre controlled trial was conducted involving 82 mothers and their infants aged 2-4months in Iran from August 2018 to April 2019. The intervention group received BSI, which included one individual 90-min class session, booklet, voice messages, and follow-up calls; while the control group received training on general infant safety. Details of infant sleep, maternal sleep quality, and postnatal depression were measured through the sleep diary, Pittsburgh Sleep Quality Index, and Edinburgh Postnatal Depression Scale, respectively, before and at 8weeks after the training. In the intervention group, both the mean infant "night-time sleep period" and infant "longest self-regulated sleep period" were 81min longer than the controls (p<.001). With an improvement of 160min, the mean infant bedtime was decreased to 22:20hours in the intervention group, substantially earlier than the controls (00:30hours). The mean infant "night-time awakenings with signals" did not significantly change (2.6- and 2.5-times in the intervention and control groups, respectively). The intervention led to a significant improvement in maternal sleep quality and depression (p<.05). The present study acknowledges the positive effects of an early preventive infant BSI on infant sleep, maternal mood, and maternal sleep. Our present results also imply the importance of considering sleep patterns differences and cultural-based intervention's design.

Bidirectional relationships between sleep and biomarkers of stress and immunity in youth

Insufficient sleep during childhood can lead to physical and mental health issues. In adults, sleep disturbances have been associated with altered levels of stress hormones and inflammatory cytokines, but data in youth is lacking. The aim of this study was to explore relationships between objective measures of sleep and salivary biomarkers in children and adolescents. Participants (N = 55, aged 8–16 years, 53% female) wore an actigraph sleep monitor in their home for seven nights and completed sleep diaries and the School Sleep Habits Survey (SSHS). Participants also donated first waking saliva samples, which were later assayed for α-amylase (sAA), cortisol, interleukin (IL)-6, and IL-1β. While sAA was not associated with objective sleep it did show a positive association with self-reported sleep disturbance. Morning cortisol levels were associated with objective sleep variables, including minutes spent awake the night before sampling, and sleep efficiency and awakenings the night after sampling. Morning IL-6 was associated with prior night sleep efficiency and minutes spent awake the night after saliva sampling. Likewise, IL-1β levels were associated with sleep duration and sleep onset latency during the nighttime sleep period prior to and after saliva sampling. These results align with other data to indicate objective elements of sleep are related to salivary cortisol, IL-6, and IL-1β in youth. Thus, quality of sleep on the night prior to sampling should be considered when investigating levels of salivary mediators in children.

Associations between parent-reported and objectively measured sleep duration and timing in infants at age 6 months.

To compare the estimates of sleep duration and timing from survey, diary, and actigraphy in infants at age 6 months, overall and by select demographics and other factors. In total, 314 infants participating in the Rise & SHINE (Sleep Health in Infancy & Early Childhood study) cohort in Boston, MA, USA, wore an actigraph on their left ankle for 7 days. Parents concurrently completed a sleep diary and the expanded version of the Brief Infant Sleep Questionnaire. Concordance between parent-reported and objective sleep estimates was assessed using Bland-Altman plots, Spearman's rank correlations, intraclass correlations, and linear regression models. Mean infant age was 6.4 (0.6 SD) months; 51% were female and 42% were Non-Hispanic white. Mean total sleep duration using actigraphy was 526 (67 SD) minutes per night, 143 (42 SD) minutes per day, and 460 (100 SD) minutes during the longest nighttime sleep period. Relative to actigraphy, parent-completed survey and diary overestimated total day (by 29 and 31 minutes, respectively) and night sleep duration (67 and 43 minutes, respectively) and underestimated the longest sleep (58 minutes), with the highest agreement for sleep onset and offset timing (differences < 30 minutes). There was a tendency toward greater bias among short- and long-sleeping infants. Self-reporting bias for diary-measured longest nighttime sleep and total night sleep duration was higher in infants of parents reporting a problem with their baby's night awakenings and in low-income families, respectively. Our findings underscore the need to be cautious when comparing findings across studies using different sleep assessment methods.

A daytime nap combined with nighttime sleep promotes learning in toddlers

Napping after learning promotes consolidation of new information during infancy. Yet, whether naps play a similar role during toddlerhood, a stage when many children are beginning to transition away from napping, is less clear. In Experiment 1, we examined whether napping after learning promotes generalization of novel category exemplars 24 h later. Young children (N = 54, age range = 29–36 months) viewed three category exemplars in different contexts from each of three categories and remained awake (No-Nap condition) or napped (Nap condition) after encoding and were then tested 24 h later. Children who napped after learning showed superior generalization 24 h later relative to children who did not nap. In a Nap-Control condition tested 4 h after awakening from a nap, children performed at the same low level as in the No-Nap condition, indicating that generalization stemmed from an additional period of nighttime sleep and not simply from a nap or increased time. In Experiment 2, we examined whether nighttime sleep is sufficient for generalization if it occurs soon after learning. An additional group of children (N = 18) learned before bedtime and were tested 4 h after waking up the next day. Children did not generalize as well as those who had a nap combined with subsequent nighttime sleep. These findings suggest that naps, when combined with a period of nighttime sleep, might help toddlers to retain newly learned information and lead to delayed benefits in generalization.

Influence of Training Schedules on Objective Measures of Sleep in Adolescent Academy Football Players.

Brown, GA, Veith, S, Sampson, JA, Whalan, M, and Fullagar, HHK. Influence of training schedules on objective measures of sleep in adolescent academy football players. J Strength Cond Res 34(9): 2515-2521, 2020-Football academy settings may pose risks to adolescent athletes achieving sufficient sleep because of the contextual challenges these players face (e.g., psychosocial pressure, changes in training, competition, and academic stress). Given the importance of sleep to overall health as well as physical athletic development and injury risk, this study aimed to investigate whether differences in training schedules (morning vs. evening training sessions) affected objective measures of sleep in adolescent academy football (soccer) players. Twelve academy players (mean age 14.18 ± 1.36 years) wore an ActiGraph accelerometer on nights before, and nights of, training days in 2 separate weeks where morning (09:00-11:00 hours) and evening (18:00-20:00 hours) training occurred. Objective sleep parameters and training load data were collected. Night-time sleep periods were categorized as sleep preceding morning training, preceding evening training, or after evening training. One-way univariate and multivariate analyses of variance for repeated measures were performed to determine the impact of the training schedule on sleep. Significance levels were set at p < 0.05. The total sleep time was below the recommended guidelines (<8 hours) across conditions. A large significant effect of the training schedule on time attempted to fall asleep (p = 0.004, effect size [ES] = 0.40) and time of sleep (p = 0.003, ES = 0.41) was present, with post-evening sessions resulting in the latest times. Overall, the players' sleep behavior was resilient to changes in training schedules. However, the low sleep durations (and potential risks to physical performance/injury) suggest that sleep education coupled with practical interventions are required in this cohort.

Fragmentation of Rest/Activity Patterns in Community-Based Elderly Individuals Predicts Incident Heart Failure.

Study ObjectivesHeart failure has previously been linked to sleep disorders that are often associated with frequent disturbances to human rest/activity patterns. We tested whether fragmentation of sustained rest/activity patterns derived from actigraphic recordings at baseline predicts incident heart failure in community-based elderly individuals.MethodsWe studied 1099 community-based elderly adults participating in the Rush Memory and Aging Project who had baseline motor activity monitoring up to 11 days and were followed annually for up to 14 years. Fragmentation was assessed using previously validated indexes, derived from the probability of transitions once sustained rest or activity has been established. Heart failure was recorded via a clinical interview during the annual follow-up. Cox proportional hazards models were constructed to examine the relationship between rest fragmentation index and incident heart failure. Covariates grouped in terms of demographics, lifestyle factors and co-morbidities and cardiovascular risk factors/diseases were included.ResultsIncreased rest fragmentation (but not activity fragmentation) was associated with higher risk for incident heart failure. Specifically, a subject with a rest fragmentation at the 90th percentile showed a 57% increased risk of developing incident heart failure compared to a subject at the 10th percentile in this cohort. This effect was equivalent to that of being over a decade older. These observations were consistent after adjusting for all covariates.ConclusionIncreased rest fragmentation, a potential surrogate for sleep fragmentation, is independently associated with a higher risk of developing heart failure in community-based elderly adults during up to 14 years of follow-up. Further work is required to examine the specific contributions from daytime napping versus nighttime sleep periods in the elderly, as well as the underlying autonomic and cardio-dynamic pathways that may explain the effects on heart function.

Neighborhood deprivation predicts infant sleep quality

ObjectivesThe current study examined the relationship between neighborhood deprivation and infant sleep at 3 months of age. MethodsNeighborhood and sleep data were collected from 80 African American infants and their caregivers. A composite neighborhood deprivation score was created using census data. Infant sleep was measured via 7 nights of actigraphy monitoring when infants were 3 months of age. Current analyses considered the average number of infant night wakings as an index of sleep quality. Multilevel models were used, in which children (level 1) were nested within census tracts (level 2). ResultsControlling for level 1 covariates, greater neighborhood deprivation (b = 0.07, P < .01), was associated with poorer infant sleep, as characterized by a greater number of wakings during the nighttime sleep period. ConclusionsFindings suggest that infants who reside in communities marked by higher deprivation experience poorer quality sleep, even after controlling for family-level factors.

Athletes underestimate sleep quantity during daytime nap opportunities

ABSTRACTThis study examined the difference between athletes’ self-reported and objective sleep durations during two nap opportunities. Twelve well-trained male soccer players’ sleep durations were assessed using polysomnography and a self-report question during a 60- and 120-min nap opportunity. Participants underestimated sleep compared to objective sleep assessments for both the 60-min nap opportunity (p = 0.004) and 120-min nap opportunity (p = 0.001). Soccer players underestimated their sleep duration by approximately 10 min per hour of nap opportunity. It is yet to be determined if athletes are likely to underestimate sleep duration during their main nighttime sleep period.

How well does a commercially available wearable device measure sleep in young athletes?

ABSTRACTThe validity of a commercially available wearable device for measuring total sleep time was examined in a sample of well-trained young athletes during night-time sleep periods and daytime naps. Participants wore a FitBit HR Charge on their non-dominant wrist and had electrodes attached to their face and scalp to enable polysomnographic recordings of sleep in the laboratory. The FitBit automatically detected 24/30 night-time sleep periods but only 6/20 daytime naps. Compared with polysomnography, the FitBit overestimated total sleep time by an average of 52 ± 152 min for night-time sleep periods, and by 4 ± 8 min for daytime naps. It is important for athletes and practitioners to be aware of the limitations of wearable devices that automatically detect sleep duration.

Circadian hemodynamics in men and women with high blood pressure: dipper vs. nondipper and racial differences.

The 'nondipping' pattern of circadian blood pressure (BP) variation is an established independent predictor of adverse cardiovascular outcomes. Although this phenomenon has been widely studied, its underlying circadian hemodynamics of cardiac output and systemic vascular resistance (SVR) have not been well characterized. We evaluated the hypothesis that BP nondipping would be associated with a blunted night-time reduction in SVR in a biracial sample of 140 (63 African-American and 77 white) men and women with elevated clinic BP (130-159/85-99 mmHg). Twenty-four-hour ambulatory hemodynamics were assessed using standard ambulatory BP monitoring coupled with synchronized ambulatory impedance cardiography. Using the criterion of less than 10% dip in SBP, there were 51 nondippers (SBP dip = 7.3 ± 2.6%) and 89 dippers (SBP dip = 15.5 ± 3.4%). There was minimal change in cardiac output from daytime to night-time in both dippers and nondippers. However, SVR decreased from daytime to night-time, but nondippers compared with dippers exhibited a significantly attenuated decrease in SVR from daytime to night-time (7.8 vs. 16.1%, P < 0.001). Relative to their white counterparts, African-Americans also exhibited blunted SBP dipping (10.9 vs. 14.6%, P < 0.001) as well as an attenuated decrease in SVR (10.8 vs. 15.6%, P < 0.001). Overall, these findings indicate that blunted night-time BP dipping is associated with impairment of the systemic vasodilation that is characteristic of the night-time sleep period and is especially prominent among African-Americans. In the context of high BP, these findings suggest that nondipping may be a manifestation, or marker, of more advanced vascular disease.

Video evidence that parenting methods predict which infants develop long night-time sleep periods by three months of age.

Most western infants develop long night-time sleep periods by four months of age. However, around 20-30% of infants in many countries continue to sleep for short periods and cry out on waking in the night: the most common type of infant sleep behaviour problem. Preventive interventions may help families and improve services. There is evidence that 'limit-setting' parenting, which is common in western cultures, supports the development of settled infant night-time behaviour. However, this evidence has been challenged. The present study measures three components of limit-setting parenting (response delay, feeding interval, settling method), examines their stability, and assesses the predictive relationship between each of them and infant sleep-waking behaviours. Longitudinal observations comparing a General-Community (n=101) group and subgroups with a Bed-Sharing (n=19) group on infra-red video, diary and questionnaire measures of parenting behaviours and infant feeding and sleep-waking at night. Findings Bed-Sharing parenting was highly infant-cued and stable. General-Community parenting involved more limit-setting, but was less stable, than Bed-Sharing parenting. One element of General-Community parenting - consistently introducing a short interval before feeding - was associated with the development of longer infant night-time feed intervals and longer day-time feeds at five weeks, compared with other General-Community and Bed-Sharing infants. Twice as many General-Community infants whose parents introduced these short intervals before feeding in the early weeks slept for long night-time periods at three months of age on both video and parent-report measures, compared with other General-Community and Bed-Sharing infants. The findings' implications for our understanding of infant sleep-waking development, parenting programmes, and for practice and research, are discussed.

Altered sleep–wake patterns in blindness: a combined actigraphy and psychometric study

ObjectiveLight plays an important role in the synchronization of the internal biological clock and the environmental day/night pattern. Thus, absence of vision is often associated with both increases in reported sleep disturbances and incidence of free-running circadian rhythms. In this study we discuss variability in the sleep–wake pattern between blind and normal-sighted individuals. MethodsThirty-day actigraphy recordings were collected from 11 blind individuals without residual light perception and 11 age- and sex-matched normal-sighted controls. From these recordings, we extracted parameters of sleep and wake, including episodes of rest, day-time and night-time sleep periods, and the number of awakenings throughout sleep. A measure of sleep efficiency was derived from these measures for each night-time sleep episode. We also examined complementary measures of sleep quality, using the Pittsburgh Sleep Quality Index, and chronotype, using the Morningness-Eveningness Questionnaire. ResultsAlthough no group differences were found when averaging over the entire recording period, we found a greater variability throughout the 30-days in both sleep efficiency and timing of the night-time sleep episode in blind participants as compared to sighted control participants. We also confirm previous reports of reduced sleep quality in blind individuals. Notably, the variability in sleep efficiency and in the timing of sleep correlated with the severity of sleep disturbances. ConclusionThe timing and physiology of sleep are strongly dependent on the endogenous circadian phase; therefore, observed findings support the hypothesis of free-running circadian rhythms as a dominant factor for the sleep disturbances experienced in blindness.

Age-related differences in sleep-dependent consolidation of motor skills in patients with narcolepsy type 1

ObjectiveThe influence of post-training sleep on the consolidation process of procedural (ie, visual and motor) knowledge has shown to be less effective in patients with chronic sleep disorders compared with healthy subjects. To ascertain whether the influence of the altered architecture of sleep in patients with narcolepsy type 1 (ie, with cataplexy: NT1) also varies with age, we compared the performance values of 16 children (aged from nine to 14 years) and 16 adults (aged from 24 to 51 years) on finger tapping task (FTT) after daytime and nighttime periods of sleep in the 24 hours following training. MethodsAll patients, who were drug-free and underwent continuous polysomnographic recordings, could take one or more naps after the training session (at 10 a.m.) until one hour before the first retrieval session (at 6 p.m.) and had an undisturbed period of nighttime sleep from about 10 p.m. to two hours before the second retrieval session (again at 10 a.m.). ResultsThe pattern of sleep-dependent consolidation was significantly different in the two groups of patients: while performance accuracy was higher in adults compared with children at each session, performance speed improved after daytime sleep in children and after nighttime sleep in adults. The improvement in performance speed, although not related with any sleep parameters in both groups, was positively correlated with the daytime and nighttime total sleep time (TST) in children with greater consolidation gain. ConclusionThe interaction between time of day and age in the time course of consolidation of new motor skills discloses a different role of daytime sleep (active in children, simply protective from interferences in adults) in NT1 patients and suggests a flexible use of napping in the educational context.

Development of infant and toddler sleep patterns: real-world data from a mobile application.

The aim of this study was to investigate the development of infant and toddler sleep patterns. Data were collected on 841 children (aged from birth to 36months) via a free, publicly available, commercially sponsored iPhone app. Analyses were conducted on caregiver recordings of 156989 sleep sessions across a 19-month period. Detailed visualizations of the development of sleep across the first 3years of life are presented. In the first 3months, sleep sessions primarily lasted less than 3.5h throughout the day. Between 3 and 7months old, sleep consolidated into two naps of about 1.5h in length and a night-time sleep session of about 10.5h. Across age groups, a negative relationship was observed between the start of bedtime and the length of the night-time sleep session (i.e. later bedtime is associated with a shorter night-time sleep period). The length of daytime sleep sessions (naps) varied with age, decreasing between 1 and 5months old, and then increasing monotonically through 28months. Morning wake time was observed to be invariant in children aged 5-36months. Sleep patterns are ever-changing across the first few years with wide individual variability. Sleep patterns start to develop more clearly at 5-6months, when longer night-time sleep duration begins and sleep consolidation occurs. Daytime sleep patterns appeared to become more consistent and consolidated later in age than night-time sleep. Finally, there is greater variability in bedtimes than wake times, with bedtimes having a greater influence on night-time sleep duration.