Physiologic brain dysmaturity in late preterm infants

Bedside monitoring tools and advanced signal processing approaches to monitor critically-ill infants

There is a substantial body of literature that supports neonatal monitoring and signal analysis of the collected data to provide valuable insights for improving patient clinical care and to inform new research studies. This comprehensive monitoring approach extends beyond the collection of conventional vital signs to include the acquisition of continuous waveform data from patient monitors and other bedside medical devices. This paper discusses the necessary infrastructure for waveform retrieval from bedside monitors, and explores options provided by leading healthcare companies, third-party vendors or academic research teams to implement scalable monitoring systems across entire critical care units. Additionally, we discuss the application of advanced signal processing that transcend traditional statistics, including heart rate variability in both the time- and frequency-domains, spectral analysis of EEG, and cerebral pressure autoregulation. The infrastructures and signal processing techniques outlined here are indispensable tools for intensivists, empowering them to enhance care for critically ill infants. In addition, we briefly address the emergence of advanced tools for fetal monitoring.

Comparative utility of MRI and EEG for early detection of cortical dysmaturation after postnatal systemic inflammation in the neonatal rat

BACKGROUND

Exposure to postnatal systemic inflammation is associated with increased risk of brain injury in preterm infants, leading to impaired maturation of the cerebral cortex and adverse neurodevelopmental outcomes. However, the optimal method for identifying cortical dysmaturation is unclear. Herein, we compared the utility of electroencephalography (EEG), diffusion tensor imaging (DTI), and neurite orientation dispersion and density imaging (NODDI) at different recovery times after systemic inflammation in newborn rats.

METHODS

Sprague Dawley rat pups of both sexes received single-daily lipopolysaccharide (LPS; 0.3 mg/kg i.p.; n = 51) or saline (n = 55) injections on postnatal days (P)1, 2, and 3. A subset of these animals were implanted with EEG electrodes. Cortical EEG was recorded for 30 min from unanesthetized, unrestrained pups at P7, P14, and P21, and in separate groups, brain tissues were collected at these ages for ex-vivo MRI analysis (9.4 T) and Golgi-Cox staining (to assess neuronal morphology) in the motor cortex.

RESULTS

Postnatal inflammation was associated with reduced cortical pyramidal neuron arborization from P7, P14, and P21. These changes were associated with dysmature EEG features (e.g., persistence of delta waveforms, higher EEG amplitude, reduced spectral edge frequency) at P7 and P14, and higher EEG power in the theta and alpha ranges at P21. By contrast, there were no changes in cortical DTI or NODDI in LPS rats at P7 or P14, while there was an increase in cortical fractional anisotropy (FA) and decrease in orientation dispersion index (ODI) at P21.

CONCLUSIONS

EEG may be useful for identifying the early evolution of impaired cortical development after early life postnatal systemic inflammation, while DTI and NODDI seem to be more suited to assessing established cortical changes.

The effect of facilitated tucking and white noise on stress and sleep of newborns receiving nasal continuous positive airway pressure

OBJECTIVE

To investigate the effects of facilitated tucking and white noise on stress and sleep in neonates receiving nasal continuous positive airway pressure (CPAP).

METHOD

This study was conducted as a randomised controlled experimental study of neonates receiving nasal CPAP in neonatal intensive care units. The study sample consisted of 108 newborns (facilitated tucking (n = 36), white noise (n = 36) and control (n = 36)) receiving nasal CPAP support in the NICU. The neonates' sleep parameters were recorded by actigraphy for 24 h. Data were collected using the Neonatal Descriptive Information Form, the Sleep Tracking Form and the Neonatal Stress Scale. Percentage, mean, chi-squared and one-way ANOVA were used for data analysis.

RESULTS

It was found that 50.9% of the newborns were female, their mean gestational age was 33.54 ± 3.38, their mean height was 43.56 ± 5.12, and their mean weight was 2139.23 ± 827.82. The total sleep time of the neonates in the facilitated tucking and white noise group increased by 3 h, their sleep efficiency increased by 20% and their mean stress scores decreased (p < 0.05).

CONCLUSION

Facilitated tucking and white noise each showed a similar improvement in sleep duration and sleep efficiency and a reduction in stress scores in neonates receiving nasal CPAP. Close monitoring of sleep in this population and supportive care practices are recommended.

PRACTICE IMPLICATIONS

The findings of this study may help to reduce sleep problems and stress levels in the clinical care of neonates in the NICU through developmental nursing practices.

Dysmature patterns of newborn EEG recordings: Biological markers of transitory brain dysfunction or brain injury

Perinatal hypoxic-ischemic brain injury is a major cause of non-progressive neurological deficits in children. Dysmature patterns can be seen in newborns' electroencephalograms (EEGs) and may have prognostic value for long-term outcomes.

OBJECTIVE

To investigate the prognostic value of dysmature EEG patterns in term or near-term newborns.

METHODS

Neonates with dysmature patterns in their first neonatal EEG, assessed during a 6-year period from January 2010 to December 2015, were included in the study. Their outcomes at their follow-ups in June 2019 (at the age of 3 years or more) were assessed, and the presence of neurological deficits and/or epilepsy was noted.

RESULTS

We identified 347 neonates with video-EEG recordings during the observed period, in which 10 neonates had dysmature patterns in their first EEG. Eight were born at term and two were born late preterms, born at the 35 and 36-week gestational age. The reasons for admission were HIE grade I in 2 patients, grade II in 6 neonates, and heart problems in 2 patients. The second EEG was recorded at different time intervals, in 7 infants between 1 and 6 weeks; three infants had second EEG much later and were excluded from the study. Six of seven infants showed normal background activity (BA), and five had sharp waves over different regions, all six had normal developmental outcomes. One child with dysrhythmic pattern in the second EEG was diagnosed with genetic encephalopathy, developed spastic cerebral palsy and died due to severe pneumonia at the age of 6 years.

CONCLUSION

Dysmature patterns may reflect transitory brain dysfunctions. Neonatal EEG tests remain reliable and important diagnostic tool in the very first weeks of life, particularly due to the availability of sequential EEG recordings and interpretations.

Vision-Related Quality of Life in Malaysian Children with Threshold and Pre-Threshold Retinopathy of Prematurity

Purpose

The prevalence of retinopathy of prematurity (ROP) is higher in developing countries compared to developed countries. There is limited data on vision-related quality of life (VRQoL) among children with severe type of ROP in developing countries. This study evaluated the influence of threshold and prethreshold ROP on VRQoL in Malaysian children.

Methods

Multicenter prospective cross-sectional study conducted in three tertiary hospitals in 2018 to 2019. Children less than 7 years old with previous ROP diagnosis were recruited. Patients with systemic comorbidities that affected vision or daily activities were excluded. A parent or guardian completed the Children’s Visual Function Questionnaire (CVFQ) for the assessment of child’s general health, general vision, competence, personality, family impact, and treatment difficulty.

Results

Eight were categorized with threshold ROP, 16 with high-risk prethreshold ROP, and 26 with low-risk prethreshold ROP. Fifty age-matched controls were also included. Mean visual acuity in logarithm of the minimum angle of resolution was 0.46 in the threshold, 0.08 in high-risk prethreshold, and 0.01 in low-risk prethreshold subgroups. Threshold ROP was associated with myopia and strabismus, and associated with poor visual acuity compared to prethreshold ROP. Mean total CVFQ score was significantly lower in the ROP group (p < 0.001) compared to the control group. Mean score and all mean subscale scores were significantly lower in the threshold subgroup compared to high-risk and low-risk prethreshold subgroups, with lowest subscale scores on general vision and general health. There was significant association between gestational age, visual acuity of the better eye, family income, and VRQoL (p < 0.05).

Conclusions

ROP was associated with lower VRQoL in children born prematurely in Malaysia. The threshold ROP group is the most affected. General vision and health domains are their main difficulties encountered. Gestational age, visual acuity of the better eye, and family income affects the VRQoL.

Sleep Instability Correlates with Attentional Impairment in Boys with Attention Deficit Hyperactivity Disorder

Theoretical models of sleep and attention deficit hyperactivity disorder (ADHD) suggest that symptoms of ADHD are associated with daytime sleepiness, but it has received little support. The present study aimed at testing an alternative model involving the association of attentional instability with sleep instability, i.e., sleep stage transitions and arousals. Twelve ADHD and 15 healthy control (HC) boys aged between 8 and 12 years old underwent polysomnography recording and attentional testing. The microarousal index, the number of awakenings, and the number of stage shifts between stages 1, 2, 3, 4 and REM sleep throughout the night were computed as sleep stability parameters. Attentional functioning was assessed using the Continuous Performance Test-II. We found significantly higher sleep instability in ADHD compared to HC. Sleep arousals and stage transitions (micro arousal index, stage 4/3 and 2/4 transitions) in ADHD significantly correlated with lower attentional scores. No association whatsoever was found between sleep instability and attentional functioning in HC. The results show that sleep instability is associated with lower attentional performance in boys with ADHD, but not in HC. This could be compatible with a model according to which attention and sleep stability share a common neural substrate in ADHD.

Identification and Characterization of Circular RNA as a Novel Regulator and Biomarker in Preterm Birth

Preterm birth (PTB), as the leading cause of neonatal death, is a severe threat to maternal–fetal health. The diagnosis and treatment of PTB are difficult as its underlying mechanism still unknown. Circular RNA (circRNA) is an emerging molecule that plays an essential role in the pathological processes of various diseases. However, it is still unclear whether circRNAs are abnormal or involves in the PTB pathology. In this study, we analyzed RNA-seq data of peripheral blood from preterm and term pregnant women and verified with microarray data. There were 211 circRNA expression disorders in PTB, of which 68 increased and 143 decreased. Bioinformatics analysis revealed that the top 20 circRNAs competitively bind 68 miRNAs, thereby regulating 622 mRNAs mainly related to immunity, inflammation, and nerve activity, which may ultimately contribute to the occurrence of PTB. Moreover, 6 regulatory pairs, including hsa-MORC3_0001–hsa-miR-1248–CHRM2 were the core parts of this mechanism network, which might be therapeutic targets for PTB. Besides, ROC analysis indicated that hsa-ANKFY1_0025, hsa-FAM13B_0019, and hsa-NUSAP1_0010 (AUC = 0.7138, 0.9589, 1.000) have an excellent discrimination ability for PTB. Taken together, we explored for the first time the circRNA expression profile of PTB, and preliminarily analyzed its regulatory mechanism and predictive value for PTB, thus bringing new light to the diagnosis and treatment of PTB.

Transfer Entropy Modeling of Newborn Cardiorespiratory Regulation

This study investigates the complex interplay between the cardiac and respiratory systems in 268 healthy neonates born between 35 and 40 weeks of gestation. The aim is to provide a comprehensive description of the developing cardiorespiratory information transfer mechanisms as a function of gestational age (GA). This report proposes an extension of the traditional Transfer Entropy measure (TE), which employs multiple lagged versions of the time series of the intervals between two successive R waves of the QRS signal on the electrocardiogram (RR series) and respiration time series (RESP). The method aims to quantify the instantaneous and delayed effects between the two processes within a fine-grained time scale. Firstly, lagged TE was validated on a simulated dataset. Subsequently, lagged TE was employed on newborn cardiorespiratory data. Results indicate a progressive increase in information transfer as a function of gestational age, as well as significant differences in terms of instantaneous and delayed interactions between the cardiac and the respiratory system when comparing the two TE directionalities (RR→RESP vs. RESP→RR). The proposed investigation addresses the role of the different autonomic nervous system (ANS) branches involved in the cardiorespiratory system, since the sympathetic and parasympathetic branches operate at different time scales. Our results allow to infer that the two TE directionalities are uniquely and differently modulated by both branches of the ANS. TE adds an original quantitative tool to understanding cardiorespiratory imbalance in early infancy.

Applying a data-driven approach to quantify EEG maturational deviations in preterms with normal and abnormal neurodevelopmental outcomes

Premature babies are subjected to environmental stresses that can affect brain maturation and cause abnormal neurodevelopmental outcome later in life. Better understanding this link is crucial to developing a clinical tool for early outcome estimation. We defined maturational trajectories between the Electroencephalography (EEG)-derived ‘brain-age’ and postmenstrual age (the age since the last menstrual cycle of the mother) from longitudinal recordings during the baby’s stay in the Neonatal Intensive Care Unit. Data consisted of 224 recordings (65 patients) separated for normal and abnormal outcome at 9–24 months follow-up. Trajectory deviations were compared between outcome groups using the root mean squared error (RMSE) and maximum trajectory deviation (δ^max). 113 features were extracted (per sleep state) to train a data-driven model that estimates brain-age, with the most prominent features identified as potential maturational and outcome-sensitive biomarkers. RMSE and δ^max showed significant differences between outcome groups (cluster-based permutation test, p < 0.05). RMSE had a median (IQR) of 0.75 (0.60–1.35) weeks for normal outcome and 1.35 (1.15–1.55) for abnormal outcome, while δ^max had a median of 0.90 (0.70–1.70) and 1.90 (1.20–2.90) weeks, respectively. Abnormal outcome trajectories were associated with clinically defined dysmature and disorganised EEG patterns, cementing the link between early maturational trajectories and neurodevelopmental outcome.

Maternal Voice and Infant Sleep in the Neonatal Intensive Care Unit

BACKGROUND

Approximately 10% of US newborns require a NICU. We evaluated whether the NICU acoustic environment affects neonatal sleep and whether exposure to the mother's voice can modulate that impact.

METHODS

In a level IV NICU with single-infant rooms, 47 neonates underwent 12-hour polysomnography. Their mothers were recorded reading children's books. Continuous maternal voice playback was randomized to either the first or second 6 hours of the polysomnogram. Regression models were used to examine sleep-wake stages, entropy, EEG power, and the probability of awakening in response to ambient noise during and without voice playback.

RESULTS

After epochs with elevated noise, the probability was higher with (versus without) maternal voice exposure of neonates staying asleep (P = .009). However, the 20 neonates born at ≥35 weeks' gestation, in contrast to those born at 33 to 34 weeks, showed an age-related increase in percent time awake (R ² = 0.52; P < .001), a decrease in overall sleep (R ² = 0.52; P < .001), a reduction in rapid eye movement sleep bouts per hour (R ² = 0.35; P = .003), and an increase in sleep-wake entropy (R ² = 0.52; P < .001) all confined solely to the 6 hours of maternal voice exposure. These associations remained significant (P = .02 to P < .001) after adjustment for neurologic examination scores and ambient noise.

CONCLUSIONS

Hospitalized newborns born at ≥35 weeks' gestation but not at 33 to 34 weeks' gestation show increasing wakefulness in response to their mother's voice. However, exposure to the mother's voice during sleep may also help protect newborns from awakening after bursts of loud hospital noise.

Sleep-disordered breathing is common among term and near term infants in the NICU

OBJECTIVE

Among older infants and children, sleep-disordered breathing (SDB) has negative neurocognitive consequences. We evaluated the frequency and potential impact of SDB among newborns who require intensive care.

STUDY DESIGN

Term and near-term newborns at risk for seizures underwent 12-h attended polysomnography in the neonatal intensive care unit (NICU). Bayley Scales of Infant Development, third edition (Bayley-III) were administered at 18-22 months.

RESULT

The 48 newborns (EGA 39.3 ± 1.6) had a median pediatric apnea-hypopnea index (AHI) of 10.1 (3.3-18.5) and most events were central (vs obstructive). Maternal and prenatal factors were not associated with AHI. Moreover, neonatal PSG results were not associated with Bayley-III scores (P > 0.05).

CONCLUSION

SDB is common among term and near-term newborns at risk for seizures. Follow-up at ages when more nuanced testing can be performed may be necessary to establish whether neonatal SDB is associated with long-term neurodevelopmental disability.

Gestational age at birth and sleep duration in early childhood in three population-based cohorts

Background

Both preterm and post-term births have been associated with neonatal morbidity and mortality, including adverse impact on neurodevelopment. Important neural maturational processes take place during sleep in newborns, but findings on gestational duration and sleep in early childhood are contradictory and often derive from small clinical samples. We studied the association of gestational age at birth with sleep duration in early childhood in three population-based cohorts.

Methods

Gestational age at birth and sleep duration were assessed in three population-based cohort studies in The Netherlands (n = 6471), Singapore (n = 862), and Canada (n = 583). Gestational age at birth was assessed using ultrasound in pregnancy in combination with date of birth, and caregivers repeatedly reported on child sleep duration at three, six, 24, and 36 months of age. Generalized estimating equations were used, which were adjusted for confounders, and findings were pooled in a meta-analysis.

Results

Children born preterm (<37 weeks of gestation) showed longer sleep duration than children born at term; and children born post-term (≥42 weeks of gestation) showed shorter sleep duration. The meta-analysis indicated a small negative effect of gestational age on child sleep duration (effect size −0.11), when assessed in children born at term only.

Conclusion

In early childhood, children with a lower gestational age have a longer sleep duration, even when they are born at term (37–42 weeks of gestation). These subtle yet consistent findings point to the importance of maturational processes during sleep, not only in premature children but also in children born at term after shorter gestational duration.

•

Children born after shorter gestational duration sleep longer than their term born peers.

•

Lower gestational age is linked to longer sleep duration in three cohorts, even in term born children (37-42 weeks gestation).

•

The association between gestational age and sleep duration is most prominent in the first year of life.

•

Our subtle yet consistent findings point to the importance of maturational processes during sleep.

•

Maturational processes underlying the interplay between gestational age and sleep duration should be investigated.

Late Preterm Infants' Social Competence, Motor Development, and Cognition

The aim of this study was to compare the social competence, motor development, and cognition of late preterm infants (LPIs) with full-term infants. Several studies in the recent past indicated that LPIs are at high risk of social development problems. We compared the development of motor skills, cognition, and social competency of LPIs with full-term infants at between 2 and 2.5 years old. The Chinese versions of the Gesell Development Diagnosis scale and the Normal Development of Social Skills from Infants to Junior High School Children scale were used for the assessment. LPIs were not more socially competent than their full-term counterparts. Each skill-namely, adaptability, gross motor, fine motor, language, and personal-social responses-was separately associated with the total level of social skills. It was found that gross motor skills had a positive correlation with the self-help and locomotive abilities, and fine motor skills had a positive association with locomotion abilities. LPIs had risk factors due to their delayed social skills in areas including motor disorders and physiological and perinatal factors. LPIs under three were at a higher risk of impairment in social competency. Therefore, it is recommended that they be monitored regularly to identify the development of social and cognitive disorders at an early stage.

Maturational Changes of Delta Waves in Monozygotic and Dizygotic Infant Twins

AIMS

To compare developmental changes of delta 1 (0.5-2.0 Hz) and delta 2 (2.25-3.75 Hz) power spectra between healthy monozygotic (MZ) and dizygotic (DZ) twin pairs and among MZ and DZ twin groups during active/REM (AS/REM) and quiet/NREM (QS/NREM) sleep stages at 38th, 46th, and 52nd weeks of postmenstrual age (PMA).

MATERIALS AND METHODS

Electroencephalography (EEG) recordings were analyzed using fast Fourier transforms. Differences in the developmental changes of delta power within twin pairs and between twin groups were estimated by calculating mean absolute differences of relative spectral values in delta 1 (0.5-2 Hz) and delta 2 (2.25-3.75 Hz) frequencies.

RESULTS

A review of electrodes showed that relative delta 1 power decreased, whereas delta 2 power increased from 38th toward 52nd week of PMA regardless of zygosity, sleep stages, and electrode position. Twin groups did not significantly differ (P > .05) in within-pair MZ and DZ similarity for delta 1 and delta 2 power spectra; similarity between MZ twin partners for delta 1 and delta 2 power spectra was as high as that of DZ twin partners on each electrode position, sleep stage, and period of measurement.

CONCLUSIONS

Developmental changes of delta 1 and delta 2 power spectra occurred equally in MZ and DZ twin groups during AS and QS sleep stages at 38th, 46th, and 52th PMA. The rhythm of EEG maturation evidenced by the maturation of delta 1 and delta 2 power spectra was not dependent on zygosity.

Waking up too early - the consequences of preterm birth on sleep development

Good quality sleep of sufficient duration is vital for optimal physiological function and our health. Sleep deprivation is associated with impaired neurocognitive function and emotional control, and increases the risk for cardiometabolic diseases, obesity and cancer. Sleep develops during fetal life with the emergence of a recognisable pattern of sleep states in the preterm fetus associated with the development, maturation and connectivity within neural networks in the brain. Despite the physiological importance of sleep, surprisingly little is known about how sleep develops in individuals born preterm. Globally, an estimated 15 million babies are born preterm (<37 weeks gestation) each year, and these babies are at significant risk of neural injury and impaired brain development. This review discusses how sleep develops during fetal and neonatal life, how preterm birth impacts on sleep development to adulthood, and the factors which may contribute to impaired brain and sleep development, leading to altered neurocognitive, behavioural and motor capabilities in the infant and child. Going forward, the challenge is to identify specific risk factors for impaired sleep development in preterm babies to allow for the design of interventions that will improve the quality and quantity of sleep throughout life.

Neonatal Sleep-Wake Analyses Predict 18-month Neurodevelopmental Outcomes

Objectives

The neurological examination of critically ill neonates is largely limited to reflexive behavior. The exam often ignores sleep-wake physiology that may reflect brain integrity and influence long-term outcomes. We assessed whether polysomnography and concurrent cerebral near-infrared spectroscopy (NIRS) might improve prediction of 18-month neurodevelopmental outcomes.

Methods

Term newborns with suspected seizures underwent standardized neurologic examinations to generate Thompson scores and had 12-hour bedside polysomnography with concurrent cerebral NIRS. For each infant, the distribution of sleep-wake stages and electroencephalogram delta power were computed. NIRS-derived fractional tissue oxygen extraction (FTOE) was calculated across sleep-wake stages. At age 18-22 months, surviving participants were evaluated with Bayley Scales of Infant Development (Bayley-III), 3rd edition.

Results

Twenty-nine participants completed Bayley-III. Increased newborn time in quiet sleep predicted worse 18-month cognitive and motor scores (robust regression models, adjusted r2 = 0.22, p = .007, and 0.27, .004, respectively). Decreased 0.5-2 Hz electroencephalograph (EEG) power during quiet sleep predicted worse 18-month language and motor scores (adjusted r2 = 0.25, p = .0005, and 0.33, .001, respectively). Predictive values remained significant after adjustment for neonatal Thompson scores or exposure to phenobarbital. Similarly, an attenuated difference in FTOE, between neonatal wakefulness and quiet sleep, predicted worse 18-month cognitive, language, and motor scores in adjusted analyses (each p < .05).

Conclusions

These prospective, longitudinal data suggest that inefficient neonatal sleep-as quantified by increased time in quiet sleep, lower electroencephalogram delta power during that stage, and muted differences in FTOE between quiet sleep and wakefulness-may improve prediction of adverse long-term outcomes for newborns with neurological dysfunction.

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.

Social brain circuitry and social cognition in infants born preterm

Preterm birth is associated with an increased risk of adverse neurologic, psychiatric, and cognitive outcomes. The brain circuits involved in processing social information are critical to all of these domains, but little work has been done to examine whether and how these circuits may be especially sensitive to prematurity. This paper contains a brief summary of some of the cognitive, psychiatric, and social outcomes associated with prematurity, followed by a description of findings from the modest body of research into social-cognitive development in infants and children born preterm. Next, findings from studies of structural and functional brain development in infants born preterm are reviewed, with an eye toward the distinctive role of the brain circuits implicated in social functioning. The goal of this review is to investigate the extent to which the putative "social brain" may have particular developmental susceptibilities to the insults associated with preterm birth, and the role of early social-cognitive development in later neurodevelopmental outcomes. Much work has been done to characterize neurobehavioral outcomes in the preterm population, but future research must incorporate both brain and behavioral measures to identify early biomarkers linked to later emerging social-cognitive clinical impairment in order to guide effective, targeted intervention.

Newborns' sleep-wake cycle development on amplitude integrated electroencephalography

BACKGROUND

To observe the development of neonatal sleep among healthy infants of different conceptional age (CA) by analyzing the amplitude-integrated electroencephalography (aEEG) of their sleep-wake cycles (SWC).

METHODS

Bedside aEEG monitoring was carried out for healthy newborns from 32 to 46 weeks CA between September 1, 2011 and August 30, 2012. For each aEEG tracing, mean duration of every complete SWC, number of SWC repetition within 12 hours, mean duration of each narrow and broadband of SWC, mean voltage of the upper edge and lower edge of SWC, mean bandwidth of SWC were counted and calculated. Analysis of the correlations between voltages or bandwidth of SWC and CA was performed to assess the developmental changes of central nervous system of newborns with different CA.

RESULTS

The SWC of different CA on aEEG showed clearly identifiable trend after 32 weeks of CA. The occurrence of SWC gradually increases from preterm to post-term infants; term infants had longer SWC duration. The voltage of upper edge of the broadband decreased at 39 weeks, while the lower edge voltage increases and the bandwidth of broadband declined along with the growing CA. The upper edge of the narrowband dropped while the lower edge rised gradually, especially in preterm stage. The width of the narrowband narrowed down while CA increased.

CONCLUSIONS

The SWC on aEEG of 32-46 weeks infants showed a continuous, dynamic and developmental progress. The appearance of SWC and the narrowing bandwidth of narrowband is the main indicator to identify the CA-dependent SWC from the preterm to the late preterm period. The lower edge of the broadband identifies the term to post-term period.

Circadian Sleep Patterns in Toddlers Born Preterm: Longitudinal Associations with Developmental and Health Concerns

OBJECTIVE

Children born preterm are at elevated risk for several developmental and health concerns. Early sleep patterns may be associated with these concerns. The current study assesses the associations between toddler circadian sleep/activity patterns and later developmental, behavioral, attentional, and health concerns in this at-risk population.

METHOD

We examined circadian sleep/activity patterns at 2 years of age in 99 children born preterm. Child cognitive skills were tested at 3 years of age, and behavior, attention, and health concerns were reported at 3 and 6 years of age. First, sleep/activity data collected via actigraphy were assessed using time series analysis (TSA). For this, we assessed how each child's sleep/activity pattern compared to a specified 24-hour circadian cycle (SCC) with an adjustment for daytime napping. Second, in a series of regression models child sleep/activity parameters from the TSA were assessed with child gender, prematurity, and family sociodemographic assets as covariates.

RESULTS

Toddlers with patterns that closely aligned with the SCC had higher abbreviated intelligence quotient scores at 3 years of age. Additionally, at 6 years these children had a lower risk for illness-related medical visits. Higher toddler average activity level was associated with fewer teacher-reported attention-deficit hyperactivity disorder symptoms and a lower risk for illness-related medical visits.

CONCLUSION

The novel approach used in this study to index child circadian patterns provides a pattern-based analysis of sleep/activity, which may prove to be developmentally consequential. With replication, these findings may help practitioners promote optimal cognitive and health development via circadian sleep supports in infants born preterm.

A. Holland A, Badawi N. The impact of surgery on the developmental status of late preterm infants - a cohort study

AIMS

Despite increasing evidence in the literature regarding the impact of late prematurity on subsequent developmental impairment, the developmental outcome of late preterm infants who undergo major surgery remains unclear. The aim of this study therefore was to determine the developmental outcome for a cohort of late preterm surgical population.

METHODS

Late preterm infants with a gestational age from 34-36 weeks inclusive who were enrolled in the state-wide prospective Development After Infant Surgery (DAISy) study and who had undergone non-cardiac major surgery within the first ninety days of life were eligible for inclusion. Infants were assessed at one and three years of ages.

RESULTS

Forty-six infants were enrolled in the study, of which 38 infants had a complete developmental assessment at one year of age. Of these infants, late preterm infants scored significantly lower than the standardized norms of the assessment on the expressive language and gross motor subscales. At three years of age 26 infants were reassessed: late preterm infants who underwent major surgery only scored significantly lower than the standardized norms on the cognitive subscale (p less than 0.001).

CONCLUSIONS

These data provide the evidence that late preterm infants who undergo major non-cardiac surgery are at risk of developmental impairment and consideration should be given to enrolling this cohort in multi-disciplinary developmental follow-up clinics.

Late preterm birth: a review of medical and neuropsychological childhood outcomes

Late preterm (LP) birth (34 0/7 - 36 6/7 weeks' gestation) accounts for nearly three-fourths of all preterm births, making this population a sizeable public health concern. The immature fetal development associated with LP delivery increases the risk of mortality and short-term medical complications. Which combination of maternal, fetal, or neonatal risk factors may be most critical has only recently begun to be addressed, and whether LP birth's disruptive impact on brain development will exert adverse effects on neuropsychological functioning in childhood and adolescence has been understudied. Early data have shown a graded response, with LP children often functioning better than very preterm children but worse than term children, and with subtle intellectual and neuropsychological deficits in LP children compared with healthy children born at term gestational age. Further characterization of the neuropsychological profile is required and would be best accomplished through prospective longitudinal studies. Moreover, since moderate and LP births result in disparate medical and psychological outcomes, the common methodology of combining these participants into a single research cohort to assess risk and outcome should be reconsidered. The rapidly growing LP outcomes literature reinforces a critical principle: fetal development occurs along a dynamic maturational continuum from conception to birth, with each successive gestational day likely to improve overall outcome.

Automatic detection of burst synchrony in preterm infants

Electroencephalographic characteristics are useful in assessment of the functional status of specific neuronal connections relative to postmenstrual age. Interhemispheric burst synchrony (IBS) is a measure of the functional connectivity between the hemispheres in the maturing preterm brain. An algorithm was developed to assess IBS and was used in a prospective, longitudinal EEG study on 18 very preterm infants (< 32 weeks gestational age) with normal follow-up at 2 years of age. The preterm infants underwent weekly 4-hour multi-channel EEG recordings, resulting in n = 77 EEGs. After automated detection of bursts, the algorithm defines the start and end of interhemispheric synchronous burst activity, based on selection criteria found in literature. The algorithm was designed to emulate visual inspection, providing objective results in an automated manner. This approach may be applied in clinical use and open novel avenues to automated analysis in EEG monitoring and, moreover, it may facilitate assessment of the functional status of interhemispheric connections. As such, assessment of low interhemispheric synchrony may be associated with brain injury.