Rapid eye movement (REM) in premature neonates and developmental outcome at 6 months

Short apneas and periodic breathing in preterm infants in the neonatal intensive care unit-Effects of sleep position, sleep state, and age

This observational study investigated the effects of sleep position and sleep state on short apneas and periodic breathing in hospitalized preterm infants longitudinally, in relation to postmenstrual age. Preterm infants (25-31 weeks gestation, n = 29) were studied fortnightly after birth until discharge, in prone and supine positions, and in quiet sleep and active sleep. The percentage of time spent in each sleep state (percentage of time in quiet sleep and percentage of time in active sleep), percentage of total sleep time spent in short apneas and periodic breathing, respectively, the percentage of falls from baseline in heart rate, arterial oxygen saturation and cerebral tissue oxygenation index during short apneas and periodic breathing, and the associated percentage of total sleep time with systemic (arterial oxygen saturation < 90%) and cerebral hypoxia (cerebral tissue oxygenation index < 55%) were analysed using a linear mixed model. Results showed that the prone position decreased (improved) the percentage of falls from baseline in arterial oxygen saturation during both short apneas and periodic breathing, decreased the proportion of infants with periodic breathing and the periodic breathing-associated percentage of total sleep time with cerebral hypoxia. The percentage of time in quiet sleep was higher in the prone position. Quiet sleep decreased the percentage of total sleep time spent in short apneas, the short apneas-associated percentage of falls from baseline in heart rate, arterial oxygen saturation, and proportion of infants with systemic hypoxia. Quiet sleep also decreased the proportion of infants with periodic breathing and percentage of total sleep time with cerebral hypoxia. The effects of sleep position and sleep state were not related to postmenstrual age. In summary, when sleep state is controlled for, the prone sleeping position has some benefits during both short apneas and periodic breathing. Quiet sleep improves cardiorespiratory stability and is increased in the prone position at the expense of active sleep, which is critical for brain maturation. This evidence should be considered in positioning preterm infants.

Machine Learning-Derived Active Sleep as an Early Predictor of White Matter Development in Preterm Infants

White matter dysmaturation is commonly seen in preterm infants admitted to the neonatal intensive care unit (NICU). Animal research has shown that active sleep is essential for early brain plasticity. This study aimed to determine the potential of active sleep as an early predictor for subsequent white matter development in preterm infants. Using heart and respiratory rates routinely monitored in the NICU, we developed a machine learning-based automated sleep stage classifier in a cohort of 25 preterm infants (12 females). The automated classifier was subsequently applied to a study cohort of 58 preterm infants (31 females) to extract active sleep percentage over 5-7 consecutive days during 29-32 weeks of postmenstrual age. Each of the 58 infants underwent high-quality T2-weighted magnetic resonance brain imaging at term-equivalent age, which was used to measure the total white matter volume. The association between active sleep percentage and white matter volume was examined using a multiple linear regression model adjusted for potential confounders. Using the automated classifier with a superior sleep classification performance [mean area under the receiver operating characteristic curve (AUROC) = 0.87, 95% CI 0.83-0.92], we found that a higher active sleep percentage during the preterm period was significantly associated with an increased white matter volume at term-equivalent age [β = 0.31, 95% CI 0.09-0.53, false discovery rate (FDR)-adjusted p-value = 0.021]. Our results extend the positive association between active sleep and early brain development found in animal research to human preterm infants and emphasize the potential benefit of sleep preservation in the NICU setting.

Loss of sleep when it is needed most - Consequences of persistent developmental sleep disruption: A scoping review of rodent models

Sleep is an essential component of development. Developmental sleep disruption (DSD) impacts brain maturation and has been associated with significant consequences on socio-emotional development. In humans, poor sleep during infancy and adolescence affects neurodevelopmental outcomes and may be a risk factor for the development of autism spectrum disorder (ASD) or other neuropsychiatric illness. Given the wide-reaching and enduring consequences of DSD, identifying underlying mechanisms is critical to best inform interventions with translational capacity. In rodents, studies have identified some mechanisms and neural circuits by which DSD causes later social, emotional, sensorimotor, and cognitive changes. However, these studies spanned methodological differences, including different developmental timepoints for both sleep disruption and testing, different DSD paradigms, and even different rodent species. In this scoping review on DSD in rodents, we synthesize these various studies into a cohesive framework to identify common neural mechanisms underlying DSD-induced dysfunction in brain and behavior. Ultimately, this review serves the goal to inform the generation of novel translational interventions for human developmental disorders featuring sleep disruption.

Sleep state organisation of moderate to late preterm infants in the neonatal unit

BACKGROUND

Sleep supports neurodevelopment and sleep architecture reflects brain maturation. This prospective observational study describes the nocturnal sleep architecture of healthy moderate to late preterm (MLP) infants in the neonatal unit at 36 weeks post menstrual age (PMA).

METHODS

MLP infants, in the neonatal unit of a tertiary hospital in Ireland from 2017 to 2018, had overnight continuous electroencephalography (cEEG) with video for a minimum 12 h at 36 weeks PMA. The total sleep time (TST) including periods of active sleep (AS), quiet sleep (QS), indeterminate sleep (IS), wakefulness and feeding were identified, annotated and quantified.

RESULTS

A total of 98 infants had cEEG with video monitoring suitable for analysis. The median (IQR) of TST in the 12 h period was 7.09 h (IQR 6.61-7.76 h), 4.58 h (3.69-5.09 h) in AS, 2.02 h (1.76-2.36 h) in QS and 0.65 h (0.48-0.89 h) in IS. The total duration of AS was significantly lower in infants born at lower GA (p = 0.007) whilst the duration of individual QS periods was significantly higher (p = 0.001).

CONCLUSION

Overnight cEEG with video at 36 weeks PMA showed that sleep state architecture is dependent on birth GA. Infants with a lower birth GA have less AS and more QS that may have implications for later neurodevelopment.

IMPACT

EEG provides objective information about the sleep organisation of the moderate to late preterm (MLP) infant. Quantitative changes in sleep states occur with each week of advancing gestational age (GA). Active sleep (AS) is the dominant sleep state that was significantly lower in infants born at lower GA. MLP infants who were exclusively fed orally had a shorter total sleep time and less AS compared to infants who were fed via nasogastric tube.

Sleep State Trend (SST), a bedside measure of neonatal sleep state fluctuations based on single EEG channels

OBJECTIVE

To develop and validate an automated method for bedside monitoring of sleep state fluctuations in neonatal intensive care units.

METHODS

A deep learning-based algorithm was designed and trained using 53 EEG recordings from a long-term (a)EEG monitoring in 30 near-term neonates. The results were validated using an independent dataset from 30 polysomnography recordings. In addition, we constructed Sleep State Trend (SST), a bedside-ready means for visualizing classifier outputs.

RESULTS

The accuracy of quiet sleep detection in the training data was 90%, and the accuracy was comparable (85-86 %) in all bipolar derivations available from the 4-electrode recordings. The algorithm generalized well to a polysomnography dataset, showing 81% overall accuracy despite different signal derivations. SST allowed an intuitive, clear visualization of the classifier output.

CONCLUSIONS

Fluctuations in sleep states can be detected at high fidelity from a single EEG channel, and the results can be visualized as a transparent and intuitive trend in the bedside monitors.

SIGNIFICANCE

The Sleep State Trend (SST) may provide caregivers and clinical studies a real-time view of sleep state fluctuations and its cyclicity.

Rapid Eye Movement Sleep during Early Life: A Comprehensive Narrative Review

The ontogenetic sleep hypothesis suggested that rapid eye movement (REM) sleep is ontogenetically primitive. Namely, REM sleep plays an imperative role in the maturation of the central nervous system. In coincidence with a rapidly developing brain during the early period of life, a remarkably large amount of REM sleep has been identified in numerous behavioral and polysomnographic studies across species. The abundant REM sleep appears to serve to optimize a cerebral state suitable for homeostasis and inherent neuronal activities favorable to brain maturation, ranging from neuronal differentiation, migration, and myelination to synaptic formation and elimination. Progressively more studies in Mammalia have provided the underlying mechanisms involved in some REM sleep-related disorders (e.g., narcolepsy, autism, attention deficit hyperactivity disorder (ADHD)). We summarize the remarkable alterations of polysomnographic, behavioral, and physiological characteristics in humans and Mammalia. Through a comprehensive review, we offer a hybrid of animal and human findings, demonstrating that early-life REM sleep disturbances constitute a common feature of many neurodevelopmental disorders. Our review may assist and promote investigations of the underlying mechanisms, functions, and neurodevelopmental diseases involved in REM sleep during early life.

Pediatric sleep and pain: etiologies, consequences, and clinical considerations

STUDY OBJECTIVES

To examine current evidence of the relationship between sleep and pain from the neonatal period through adolescence. This review serves as a critical review of the literature and of the needs for future research on pediatric sleep and pain.

METHODS

The PubMed online database was queried from January 1, 1960, to March 1, 2020, producing 149 articles applicable to pain and sleep in the pediatric population. Of those, 97 articles were cited in this review with the key articles including over 3800 participants.

RESULTS

The pediatric literature supports the relationship between poor sleep (both sleep efficiency and nighttime awakenings) and subsequent risk for pain, especially among children with chronic disease. The reverse effect of pain on sleep is not yet well delineated. The key moderating factors explored in the literature are pharmacologic and nonpharmacologic therapies, psychologic health, and the etiology of pain. There is evidence that both altered sleep and pain early in life impact neurodevelopment, as seen by changes in sleep structure in clinical studies and alterations in brain development in animal models.

CONCLUSIONS

The complicated relationship between sleep and pain is critically important during pediatric development when alterations to a normal sleep structure can have a lifelong impact. It is becoming clear that sleep deprivation and poor sleep quality exacerbate pain. Further research is needed into the complex alterations of sleep in chronic pain conditions as well as treatments to improve sleep in pediatric care.

CITATION

Morris EE, Howell MJ, Pickup E, Iber C, Wang SG. Pediatric sleep and pain: etiologies, consequences, and clinical considerations. J Clin Sleep Med. 2022;18(9):2281-2289.

Association of fetal eye movement density with sleeping and developmental problems in 1.5-year-old infants

Eye movement density (EMD) is an evaluation index of rapid eye movements observed during sleep. This study aimed to investigate the association of fetal EMD with sleeping and developmental problems in infancy. We observed 60 normal singleton pregnancies (gestational age 28-37 weeks) using ultrasonography for 1 h. Fetal eye movements were counted, and EMD was calculated. Participants answered questionnaires regarding their child's sleep and development 1.5 years after their delivery. The outcomes of an infant's sleep were night awakening (yes or no), bedtime (before or after 22:00), and nighttime sleep duration (< 9 or ≥ 9 h). An infant's development was evaluated using the Child Behavior Checklist (CBCL) T-score. We found that decreased fetal EMD was associated with increased night awakening at the age of 1.5 years (odds ratio 0.84, 95% confidence interval 0.69-1.00 per unit decrease in EMD). However, fetal EMD was not associated with bedtime or nighttime sleep duration. In addition, fetal EMD was independently associated with the total problems T-score of the CBCL at the age of 1.5 years in the multivariate model (p = 0.047). In conclusion, fetal EMD may be associated with sleep and developmental problems in infants.

The Impact of Preterm Birth on Sleep through Infancy, Childhood and Adolescence and Its Implications

There is emergent literature on the relationship between the development of sleep-wake cycles, sleep architecture, and sleep duration during the neonatal period on neurodevelopmental outcomes among children born preterm. There is also a growing literature on techniques to assess sleep staging in preterm neonates using either EEG methods or heart and respiration rate. Upon discharge from hospital, sleep in children born preterm has been assessed using parent report, actigraphy, and polysomnography. This review describes the ontogeny and measurement of sleep in the neonatal period, the current evidence on the impact of preterm birth on sleep both in the NICU and in childhood and adolescence, and the interaction between sleep, cognition, and social-emotional outcomes in this population.

Cerebral Oxygenation and Perfusion when Positioning Preterm Infants: Clinical Implications

OBJECTIVES

To evaluate cerebral tissue oxygenation (cTOI) and cerebral perfusion in preterm infants in supine vs prone positions.

STUDY DESIGN

Sixty preterm infants, born before 32 weeks of gestation, were enrolled; 30 had bronchopulmonary dysplasia (BPD, defined as the need for respiratory support and/or supplemental oxygen at 36 weeks of postmenstrual age). Cerebral perfusion, cTOI, and polysomnography were measured in both the supine and prone position with the initial position being randomized. Infants with a major intraventricular hemorrhage or major congenital abnormality were excluded.

RESULTS

Cerebral perfusion was unaffected by position or BPD status. In the BPD group, the mean cTOI was higher in the prone position compared with the supine position by a difference of 3.27% (P = .03; 95% CI 6.28-0.25) with no difference seen in the no-BPD group. For the BPD group, the burden of cerebral hypoxemia (cumulative time spent with cTOI <55%) was significantly lower in the prone position (23%) compared with the supine position (29%) (P < .001). In those without BPD, position had no effect on cTOI.

CONCLUSIONS

In preterm infants with BPD, the prone position improved cerebral oxygenation and reduced cerebral hypoxemia. These findings may have implications for positioning practices. Further research will establish the impact of position on short- and long-term developmental outcomes.

The relation between sleep and neurocognitive development in infancy and early childhood: A neuroscience perspective

Sleep is essential for human life. It has different characteristics in the early stages of life compared to later periods: during development, qualitative and quantitative changes in sleep features occur such as the onset of REM/NREM sleep at 3 months, the progressive increase of night sleep duration, and the reduction of total sleep time. Sleep seems to be essential in the cognitive functions' development, especially in the first period of life. Indeed, higher rates of night sleep at the age of 12 and 18 months are associated with higher executive functions' performance. Furthermore, memory consolidation occurs during sleep and sleep contributes to children's learning not only in retaining information but also in organizing memories most efficiently. Therefore, sleep problems could cause negative effects on some features of cognitive development like memory, executive functions, and learning process. There is also an intimate relationship between sleep and regulation of emotional brain functions, with a link between sleep disturbance and behavioral problems.

Non-contact Sleep/Wake Monitoring Using Impulse-Radio Ultrawideband Radar in Neonates

Background: The gold standard for sleep monitoring, polysomnography (PSG), is too obtrusive and limited for practical use with tiny infants or in neonatal intensive care unit (NICU) settings. The ability of impulse-radio ultrawideband (IR-UWB) radar, a non-contact sensing technology, to assess vital signs and fine movement asymmetry in neonates was recently demonstrated. The purpose of this study was to investigate the possibility of quantitatively distinguishing and measuring sleep/wake states in neonates using IR-UWB radar and to compare its accuracy with behavioral observation-based sleep/wake analyses using video recordings. Methods: One preterm and three term neonates in the NICU were enrolled, and voluntary movements and vital signs were measured by radar at ages ranging from 2 to 27 days. Data from a video camcorder, amplitude-integrated electroencephalography (aEEG), and actigraphy were simultaneously recorded for reference. Radar signals were processed using a sleep/wake decision algorithm integrated with breathing signals and movement features. Results: The average recording time for the analysis was 13.0 (7.0-20.5) h across neonates. Compared with video analyses, the sleep/wake decision algorithm for neonates correctly classified 72.2% of sleep epochs and 80.6% of wake epochs and achieved a final Cohen's kappa coefficient of 0.49 (0.41-0.59) and an overall accuracy of 75.2%. Conclusions: IR-UWB radar can provide considerable accuracy regarding sleep/wake decisions in neonates, and although current performance is not yet sufficient, this study demonstrated the feasibility of its possible use in the NICU for the first time. This unobtrusive, non-contact radar technology is a promising method for monitoring sleep/wake states with vital signs in neonates.

Behavioral-state development and sleep-state differentiation during early ontogenesis

Sleep is a key process in neurodevelopment and essential for the maturation of fundamental brain functions. Premature birth can disturb the initial steps of sleep maturation, which may contribute to the impairment of neurodevelopment. It is thus fundamental to understand the maturation of the various sleep states and the quality of cerebral function in each vigilance state, as well as the development of sleep cyclicity, in at-risk neonatal infants, particularly those born premature. The objective of this review is to provide a precise description of sleep states and cycles and their rhythmic organization in premature and term newborns according to their gestational age. Technical aspects of polysomnography, which requires a high level of expertise in neonates, are also described. Principles of the visual interpretation of polysomnography, including the simultaneous analysis of behavioral (spontaneous motricity and eye movements), polysomnographic parameters (electro-oculogram, electrocardiogram, respiration), and electroencephalography patterns are presented. The neurophysiology of sleep ontogenesis and its interaction with brain maturation are discussed, highlighting the crucial role of sleep states and their duration in premature newborns. In particular, the involvement of myoclonic twitches in functional connectivity in sensorimotor development is discussed. Indeed, sleep quality, determined by combined polysomnographic parameters, reflects either normal or pathological developmental processes during the neonatal period. The fundamental place of neurophysiological explorations in the early detection of sleep disorders is discussed, as well as their potential consequences on neurodevelopmental care to improve the prevention of neurodevelopmental impairment.

Sleep-Wake Disorders in Childhood

PURPOSE OF REVIEW

The presentation of sleep issues in childhood differs from the presentation in adulthood and may be more subtle. Sleep issues may affect children differently than adults, and distinct treatment approaches are often used in children.

RECENT FINDINGS

Sodium oxybate was approved by the US Food and Drug Administration (FDA) in October 2018 for an expanded indication of treatment of sleepiness or cataplexy in patients with narcolepsy type 1 or narcolepsy type 2 aged 7 years or older, with side effect and safety profiles similar to those seen in adults. Restless sleep disorder is a recently proposed entity in which restless sleep, daytime sleepiness, and often iron deficiency are observed, but children do not meet the criteria for restless legs syndrome or periodic limb movement disorder.

SUMMARY

Children's sleep is discussed in this article, including normal sleep patterns and effects of insufficient sleep. Sleep disorders of childhood are reviewed, including insomnia, obstructive sleep apnea, restless legs syndrome, parasomnias, narcolepsy, and Kleine-Levin syndrome. Children with neurologic issues or neurodevelopmental disorders frequently have sleep disorders arising from an interaction of heterogeneous factors. Further attention to sleep may often be warranted through a polysomnogram or referral to a pediatric sleep specialist. Sleep disorders may cause indelible effects on children's cognitive functioning, general health, and well-being, and awareness of sleep disorders is imperative for neurologists who treat children.

Revisiting the roots of attachment: A review of the biological and psychological effects of maternal skin-to-skin contact and carrying of full-term infants

During the early period of hypothesis building and empirical testing of attachment theory, a major emphasis was placed on mother-infant physical contact. In spite of this, mother-infant contact has received scant attention amongst attachment and child development researchers in the past decades. Here, a brief theoretical framework for mother-infant contact is presented, drawing on animal studies as well as human studies of preterm infants and neonates. Salient mechanisms may include an extended sensitive period during early infancy, requiring specific somatosensory stimuli for bio-behavioral homeorhesis; oxytocinergic and epigenetic pathways; kinesthetic stimuli and face-to-face proximity allowing for increased social interaction. Studies of extended human mother-full-term infant physical contact have demonstrated positive effects in multiple domains. For infants, these include sleep organization, temperature and heart rate regulation, behavioral response, crying/colic, socio-emotional development, attachment quality, speech development opportunities and mother-child interactions. For mothers, studies demonstrate improved depressive symptomatology, physiological stress regulation, contingent responsivity, breastfeeding and mother-child interactions. Parent-infant attachment quality has gained prominence as a trauma-resilience factor as well as a predictor of adult physical health. The potential role of mother-infant contact as an attachment promoting intervention as well as future research subjects are discussed. Current evidence supports the original attachment research that early maternal touch provision may influence infant socio-emotional development and attachment quality, with positive implications for mother-child relationship functioning.

Sleep architecture is related to birth season in 1-month-old infants

Individual variation in sleep quality, quantity, and architecture is pronounced in small infants. Reasons for this remain largely unclear, even though environmental and genetic factors have been suggested to play a role. In order to study the effect of birth seasons on infant sleep architecture, 85 healthy 1-month-old infants underwent an overnight polysomnography (PSG). The PSGs were conducted in 2011-2013. The cohort was divided into four subgroups according to the amount of seasonal light at the time of birth, with each group covering a period of approximately three months. The groups were labeled IL (increasing light), L (light), ID (increasing darkness), and D (dark), corresponding to spring, summer, autumn, and winter, respectively. We found the amount of stage R sleep (precursor of REM sleep, formerly active sleep) to be the highest in infants born in summer, whereas infants born in winter presented the smallest amount of stage R sleep. Infants born in summer presented the smallest amount of stage T sleep (transitional sleep), while stage T sleep was most abundant in infants born in winter. In addition, infants born in summer showed the shortest total sleep time (TST) and the smallest number of awakenings during the study night. This was the first PSG study to find out that birth season modifies the sleep architecture of infants.

Sleep and salivary cortisol in preterm neonates: a clinical, randomized, controlled, crossover study

ABSTRACT Objective: Analyze the influence of ear protectors on the baseline levels of salivary cortisol and response and total sleep time of preterm neonates during two periods of environmental management of a neonatal intermediate care unit. Method: A clinical, randomized, controlled and crossover study conducted with 12 preterm neonates. The use of ear protectors was randomized in two periods. Sleep evaluation was performed using one Alice 5 Polysomnography System and unstructured observation. Results: No significant difference was observed between the baseline levels of salivary cortisol and response in preterm neonates from the control and experimental groups, and no statistical significance was observed between the total sleep time of both groups. No relationship was observed between the baseline levels of cortisol and response and total sleep time. Conclusion: Ear protectors in preterm neonates did not influence the salivary cortisol level and total sleep time in the studied periods.

Sleep Disturbances in Newborns

The purpose of this review is to serve as an introduction to understanding sleep in the fetus, the preterm neonate and the term neonate. Sleep appears to have numerous important roles, particularly in the consolidation of new information. The sleep cycle changes over time, neonates spend the most time in active sleep and have a progressive shortening of active sleep and lengthening of quiet sleep. Additionally, the sleep cycle is disrupted by many things including disease state and environment, and the amplitude integrated EEG can be a useful tool in evaluating sleep, and sleep disturbances, in neonates. Finally, there are protective factors for infant sleep that are still being studied.

Review of sleep-EEG in preterm and term neonates

Neonatal sleep is a crucial state that involves endogenous driven brain activity, important for neuronal survival and guidance of brain networks. Sequential EEG-sleep analysis in preterm infants provides insights into functional brain integrity and can document deviations of the biologically pre-programmed process of sleep ontogenesis during the neonatal period. Visual assessment of neonatal sleep-EEG, with integration of both cerebral and non-cerebral measures to better define neonatal state, is still considered the gold standard. Electrographic patterns evolve over time and are gradually time locked with behavioural characteristics which allow classification of quiet sleep and active sleep periods during the last 10weeks of gestation. Near term age, the neonate expresses a short ultradian sleep cycle, with two distinct active and quiet sleep, as well as brief periods of transitional or indeterminate sleep. Qualitative assessment of neonatal sleep is however challenged by biological and environmental variables that influence the expression of EEG-sleep patterns and sleep organization. Developing normative EEG-sleep data with the aid of automated analytic methods, can further improve our understanding of extra-uterine brain development and state organization under stressful or pathological conditions. Based on those developmental biomarkers of normal and abnormal brain function, research can be conducted to support and optimise sleep in the NICU, with the ultimate goal to improve therapeutic interventions and neurodevelopmental outcome.

Eye movement activity in normal human fetuses between 24 and 39 weeks of gestation

Rapid eye movement (REM) sleep occurs throughout a relatively large proportion of early development, and normal REM activity appears to be required for healthy brain development. The eye movements (EMs) observed during REM sleep are the most distinctive characteristics of this state. EMs are used as an index of neurological function postnatally, but no specific indices of EM activity exist for fetuses. We aimed to identify and characterize EM activity, particularly EM bursts suggestive of REM periods, in fetuses with a gestational age between 24 and 39 weeks. This cross-sectional study included 84 normal singleton pregnancies. Fetal EMs were monitored using real-time ultrasonography for 60 min and recorded as videos. The videos were manually converted into a time series of EM events, which were then analyzed by piecewise linear regression for various EM characteristics, including EM density, EM burst density, density of EMs in EM bursts, and continuous EM burst time. Two critical points for EM density, EM burst density, and density of EMs in EM bursts were evident at gestation weeks 28–29 and 36–37. Overall EM activity in human fetuses increased until 28–29 weeks of gestation, then again from 36–37 to 38–39 weeks of gestation. These findings may be useful for creating indices of fetal neurological function for prognostic purposes.

The Visual Scoring of Sleep in Infants 0 to 2 Months of Age

In March 2014, the American Academy of Sleep Medicine (AASM) Board of Directors requested the Scoring Manual Editorial Board develop rules, terminology, and technical specifications for scoring sleep/wake states in full-term infants from birth to 2 mo of age, cognizant of the 1971 Anders, Emde, and Parmelee Manual for Scoring Sleep in Newborns. On July 1, 2015, the AASM published rules for scoring sleep in infants, ages 0-2 mo. This evidence-based review summarizes the background information provided to the Scoring Manual Editorial Board to write these rules. The Anders Manual only provided criteria for coding physiological and behavioral state characteristics in polysomnograms (PSG) of infants, leaving specific sleep scoring criteria to the individual investigator. Other infant scoring criteria have been published, none widely accepted or used. The AASM Scoring Manual infant scoring criteria incorporate modern concepts, digital PSG recording techniques, practicalities, and compromises. Important tenets are: (1) sleep/wake should be scored in 30-sec epochs as either wakefulness (W), rapid eye movement, REM (R), nonrapid eye movement, NREM (N) and transitional (T) sleep; (2) an electroencephalographic (EEG) montage that permits adequate display of young infant EEG is: F3-M2, F4-M1, C3-M2, C4-M1, O1-M2, O2-M1; additionally, recording C3-Cz, Cz-C4 help detect early and asynchronous sleep spindles; (3) sleep onsets are more often R sleep until 2-3 mo postterm; (4) drowsiness is best characterized by visual observation (supplemented by later video review); (5) wide open eyes is the most crucial determinant of W; (6) regularity (or irregularity) of respiration is the single most useful PSG characteristic for scoring sleep stages at this age; (7) trace alternant (TA) is the only relatively distinctive EEG pattern, characteristic of N sleep, and usually disappears by 1 mo postterm replaced by high voltage slow (HVS); (8) sleep spindles first appear 44-48 w conceptional age (CA) and when present prompt scoring N; (9) score EEG activity in an epoch as "continuous" or "discontinuous" for inter-scorer reliability; (10) score R if four or more of the following conditions are present, including irregular respiration and rapid eye movement(s): (a) low chin EMG (for the majority of the epoch); (b) eyes closed with at least one rapid eye movement (concurrent with low chin tone); (c) irregular respiration; (d) mouthing, sucking, twitches, or brief head movements; and (e) EEG exhibits a continuous pattern without sleep spindles; (11) because rapid eye movements may not be seen on every page, epochs following an epoch of definite R in the absence of rapid eye movements may be scored if the EEG is continuous without TA or sleep spindles, chin muscle tone low for the majority of the epoch; and there is no intervening arousal; (12) Score N if four or more of the following conditions are present, including regular respiration, for the majority of the epoch: (a) eyes are closed with no eye movements; (b) chin EMG tone present; (c) regular respiration; and (d) EEG patterns of either TA, HVS, or sleep spindles are present; and (13) score T sleep if an epoch contains two or more discordant PSG state characteristics (either three NREM and two REM characteristics or two NREM and three REM characteristics). These criteria for ages 0-2 mo represent far more than baby steps. Like all the other AASM Manual rules and specifications none are fixed in stone, all open for debate, discussion and revision with the fundamental goal to provide standards for comparison of methods and results.

COMMENTARY

A commentary on this article appears in this issue on page 291.

The effects of flexed (fetal tucking) and extended (free body) postures on the daily sleep quantity of hospitalized premature infants: A randomized clinical trial

BACKGROUND

Proper sleep is essential for the development of premature infants. Infants, during hospitalization, might suffer from inappropriate postures and insufficient sleep hours. To compare the daily sleep quantities of premature infants in flexed (facilitated fetal tucking) posture and extended (free body) posture. This study is a randomized clinical trial which was conducted in neonatal ward of Al-Zahra Teaching Hospital of Tabriz, Iran, 2015. Thirty-two premature infants with the age range of 33-36 weeks were selected for the study.

MATERIALS AND METHODS

Every infant was studied for 4 days in a sequential format. Every infant was studied for 4 days and in a 12-h period every day (8 a.m-8 p.m). Each day, an infant was randomly put in one of the four statuses, namely, free body posture in the supine position, free body posture in the lateral position, facilitated fetal tucking in the supine position and facilitated fetal tucking in the lateral position. Films were recorded in the 12-h period (8 a.m-8 p.m). SPSS Software (version 13) was used for data analysis.

RESULTS

The results showed that about the main effect of posture on sleep variable, there was a statistically significant difference (P = 0.003). In addition, about the main effect of position on sleep variable; there was a statistically significant difference (P = 0.002). Meanwhile, there was no significant interaction effect between the posture and position for the daily sleep duration (P = 0.746). Daily sleep duration of the infants in flexed (facilitated fetal tucking) posture and lateral position is longer than that of the infants in extended (free body) posture and supine position.

CONCLUSION

Daily sleep duration in the infants experiencing flexed posture and lateral position at rest is longer. Moreover, it decreases wakefulness time of the premature infants.

Behavioral observation differentiates the effects of an intervention to promote sleep in premature infants: a pilot study

PURPOSE

Sleep and ongoing cycling of sleep states are required for neurosensory processing, learning, and brain plasticity. Many aspects of neonatal intensive care environments such as handling for routine and invasive procedures, bright lighting, and noise can create stress, disrupt behavior, and interfere with sleep in prematurely born infants. The study empirically investigated whether a 30-minute observation of infant sleep states and behavior could differentiate an intervention to promote sleep in premature infants with feeding difficulties relative to conventional care (standard positioning, standard crib mattress [SP]). We included an intervention to determine the ability of the method to discriminate treatments and generate a benchmark for future improvements. The intervention, a conformational positioner (CP), is contoured around the infant to provide customized containment and boundaries. To more fully verify the 30-minute observational sleep results, standard polysomnography was conducted simultaneously and sleep outcomes for the 2 modalities were compared.

SUBJECTS

In a randomized crossover clinical trial, 25 infants, 31.5 ± 0.6 weeks' gestational age and 38.4 ± 0.6 weeks at the study, with gastrointestinal conditions or general feeding difficulties used each intervention during an overnight neonatal intensive care unit sleep study.

METHODS

Infant sleep states and behaviors were observed during two 30-minute periods--that is, on the positioner and mattress--using the naturalistic observation of newborn behavior. Two certified developmental care nurses assessed sleep state, self-regulatory, and stress behaviors during 2-minute intervals and summed over 30 minutes. Sleep characteristics from standard polysomnography were measured at the time of behavior observations.

RESULTS

Infants on CP spent significantly less time in alert, active awake, or crying states by observation compared with SP. Surgical subjects spent more time awake, active awake, or crying and displayed a higher number of behavior state changes than the nonsurgical infants. The percentage of time in observed deep sleep and quiet sleep was correlated with both percentage sleep efficiency (r = 0.78) and fewer state shifts per hour (r = -0.65) from electroencephalogram (EEG). Sleep efficiency by EEG was greater on CP versus SP.

CONCLUSIONS

The CP enabled sleep compared with the standard mattress (SP) over 30-minute observation periods. Sleep status from behavioral observation was verified by standard EEG-based sleep techniques. Behavioral observation of sleep states may be a useful strategy for measuring the effectiveness of strategies to facilitate sleep in premature infants. Surgical subjects may benefit from additional interventions to promote sleep.

Accuracy of infrared thermometers in very low birth weight infants and impact on newborn behavioural states

AIM

To study the impact on newborn behavioural states and accuracy of three infrared thermometers compared with digital axillary thermometer measurements in very low birth weight infants.

METHODS

Single-centre prospective observational study. Preterm infants born <1500-g birth weight were eligible. Infants were observed for pre-measurement behaviour state using a five-point neonatal behaviour observation tool. One infrared temperature was taken from each of the devices, followed by an axillary measurement. Further behaviour-state observations were recorded following infrared and axillary measurements.

RESULTS

One hundred measurements were collected from each infrared device among a cohort of 42 very low birth weight infants. Only one infrared device showed satisfactory agreement with bias -0.071 (95% limits of agreement -0.68 to 0.54). The other two devices demonstrated poor agreement: bias -1.34; 95% limits of agreement -2.62 to -0.5 and bias -0.56; 95% limits of agreement -1.38 to 0.25. Neonatal behavioural scores showed only minimal changes when infrared measurements were performed but increased significantly following axillary measurements. The difference between the two modalities was statistically significant with a mean increase of 1.44 points following axillary measurements (95% confidence interval 1.21 to 1.67, P < 0.001).

CONCLUSIONS

Temperature measurements taken with infrared thermometers demonstrated less disruption to preterm infants' behavioural state, however accuracy of devices varied.

Effects of combined use of non-nutritive sucking, oral sucrose, and facilitated tucking on infant behavioural states across heel-stick procedures: a prospective, randomised controlled trial

BACKGROUND

Pain and stress agitate preterm infants, interrupting their sleep. Frequent high arousal states may affect infants' brain development and illness recovery. Preserving infants' sleep and relieving their pain during painful procedures are both important for their health.

OBJECTIVES

To compare the effectiveness of different combinations of non-nutritive sucking (sucking), oral sucrose, and facilitated tucking (tucking) with routine care on infants' sleep-wake states before, during, and after heel-stick procedures.

DESIGN

Prospective, randomised controlled trial.

SETTING

Level III Neonatal Intensive Care Unit in Taipei.

METHOD

A convenience sample of 110 infants (gestational age 26.4-37 weeks) needing heel sticks were randomly assigned to five combinations of non-pharmacological treatments: sucking-oral sucrose-tucking; sucking-oral sucrose; oral sucrose-tucking; sucking-tucking; and routine care. Infant states, measured by a state-coding scheme, included quiet sleep, active sleep, transition, quiet awake, active awake, and fussing or crying. All states were recorded at 1-min intervals during four phases: baseline, intervention, heel-stick procedures, and recovery.

RESULTS

Infants receiving sucking-oral sucrose-tucking or sucking-oral sucrose experienced 52.8% (p=0.023) and 42.6% (p=0.063) more quiet-sleep occurrences than those receiving routine care after adjusting for phase, baseline states, non-treatment sucking during baseline and recovery, positioning, and infants' characteristics. Infants receiving oral sucrose-tucking, sucking-oral sucrose, sucking-oral sucrose-tucking, and sucking-tucking experienced 77.3% (p<0.001), 72.1% (p=0.008), 51.5% (p=0.017), and 33.0% (p=0.105) fewer occurrences of fussing or crying, respectively, than those receiving routine care after adjusting for related factors.

CONCLUSIONS

The four treatment combinations differentially reduced infants' high arousal across heel-stick procedures. The combined use of oral sucrose-tucking, sucking-oral sucrose, and sucking-oral sucrose-tucking more effectively reduced occurrences of infant fussing or crying than routine care. Treatment combinations of sucking-oral sucrose-tucking and sucking-oral sucrose also better facilitated infants' sleep than routine care. To preserve infants' sleep, clinicians should use combinations of non-nutritive sucking, oral sucrose, and facilitated tucking to reduce agitation during painful procedures.

Maternal consumption of a DHA-containing functional food benefits infant sleep patterning: an early neurodevelopmental measure

BACKGROUND

Docosahexaenoic acid (DHA; 22:6n-3) is highly important during pregnancy for optimal development and functioning of fetal neural tissue. Infant ability to organize sleep and wake states following parturition is highly associated with later developmental outcomes. The impact of maternal DHA intake on sleep organization has not been previously investigated.

AIMS

To examine the effect of a DHA-containing functional food consumed during pregnancy on early neurobehavioral development as assessed by infant sleep patterning in the first 48 postnatal hours.

STUDY DESIGN

A longitudinal, randomized, double-blinded, placebo-controlled design was used.

SUBJECTS

Women (18-35 y) with no pregnancy complications consumed a cereal-based functional food (92 kcal) containing 300 mg DHA an average of 5 d/week or placebo bars (n=27 DHA, n=21 Placebo). The intervention began at 24 weeks gestation and continued until delivery (38-40 weeks).

OUTCOME MEASURES

Infant sleep/wake states were measured on postnatal days 1 (D1) and 2 (D2) using a pressure sensitive mattress recording respiration and body movements.

RESULTS

Using ANCOVA and controlling for ethnic variation, there were significant group differences in arousals in quiet sleep on D1 (P=0.006) and D2 (P=0.011) with fewer arousals in the DHA intervention group compared to the placebo group. Similarly, arousals in active sleep on D1 were significantly lower in the DHA-intervention group (P=0.012) compared to the placebo group.

CONCLUSIONS

We conclude that increased prenatal supply of dietary DHA has a beneficial impact on infant sleep organization.

Sleep-wake transitions in premature neonates predict early development

OBJECTIVE

To identify patterns of sleep-wake transitions in the neonatal period that might differentiate premature infants who would show better or worse outcomes in multiple developmental domains across the first 5 years of life.

METHODS

Participants were 143 low birth weight premature infants (mean birth weight: 1482 g; mean gestational age [GA]: 31.82 weeks). Sleep states were observed at a GA of 37 weeks in 10-second epochs over 4 consecutive evening hours and were analyzed through mathematical clustering. Neurobehavioral maturation was evaluated with the Neonatal Behavior Assessment Scale at discharge, emotional regulation was assessed during infant-mother and infant-father interactions at 3 and 6 months, cognitive development was measured at 6, 12, and 24 months, and verbal IQ, executive functions, and symbolic competence were tested at 5 years.

RESULTS

Three types of state-transition patterns were identified, and no differences in birth weight, GA, or medical risk between the 3 groups were found. Infants whose sleep-state transitions were mainly characterized by shifts between quiet sleep and wakefulness exhibited the best development, including greater neonatal neuromaturation, less negative emotionality, better cognitive development, and better verbal, symbolic, and executive competences at 5 years. In comparison, infants who cycled mainly between states of high arousal, such as active sleep and cry, or between short episodes of active and quiet sleep showed poorer outcomes.

CONCLUSIONS

Defining sleep organization on the basis of transitions between states proved useful for identifying risk and resilience indicators in neonatal behavior to predict trajectories of neurobehavioral, emotional, and cognitive growth.

A review of the effects of sleep during the first year of life on cognitive, psychomotor, and temperament development

During the first year of life, infants spend most of their time in the sleeping state. Assessment of sleep during infancy presents an opportunity to study the impact of sleep on the maturation of the central nervous system (CNS), overall functioning, and future cognitive, psychomotor, and temperament development. To assess what is currently known regarding sleep during infancy and its effects on cognitive, psychomotor, and temperament development, we assessed the relevant literature published over the last several decades. To provide a foundation for a more in-depth understanding of this literature, we preface this with an overview of brain maturation, sleep development, and various assessment tools of both sleep and development during this unique period. At present, we do not have sufficient data to conclude that a causal relationship exists between infant sleep and cognitive, psychomotor, and temperament development. Caution should be used in predicting outcomes, as the timing and subjectivity of evaluations may obviate accurate assessment. Collectively, studies assess a wide array of sleep measures, and findings from one developmental period cannot be generalized readily to other developmental periods. Future studies should follow patients longitudinally. Additionally, refinements of existing assessment tools would be useful. In view of the relatively high reported pediatric prevalence of cognitive and behavioral deficits that carry significant long-term costs to individuals and society, early screening of sleep-related issues may be a useful tool to guide targeted prevention and early intervention.