Neurobehaviour and neurological development in the first month after birth for infants born between 32-42 weeks' gestation

Multiplex dynamic networks in the newborn brain disclose latent links with neurobehavioral phenotypes

The higher brain functions arise from coordinated neural activity between distinct brain regions, but the spatial, temporal, and spectral complexity of these functional connectivity networks (FCNs) has challenged the identification of correlates with neurobehavioral phenotypes. Characterizing behavioral correlates of early life FCNs is important to understand the activity dependent emergence of neurodevelopmental performance and for improving health outcomes. Here, we develop an analysis pipeline for identifying multiplex dynamic FCNs that combine spectral and spatiotemporal characteristics of the newborn cortical activity. This data-driven approach automatically uncovers latent networks that show robust neurobehavioral correlations and consistent effects by in utero drug exposure. Altogether, the proposed pipeline provides a robust end-to-end solution for an objective assessment and quantitation of neurobehaviorally meaningful network constellations in the highly dynamic cortical functions.

The Relationship between General Movements and Risk Factors in Moderate-Late Preterm Infants: A Prospective Cohort Study

INTRODUCTION

Moderate-late preterm infants constitute the largest segment of preterm births globally. While previously considered to have a low neurological risk, recent research has uncovered an elevated incidence of neurodevelopmental conditions in this group. This study aimed to assess the relationship between the general movement assessment and birth-related risk factor-based tools in moderate-late preterm infants.

METHODS

A prospective cohort study of 65 moderate-late preterm infants in a neonatal intensive care unit involved the evaluation of general movements, the Nursery Neurobiologic Risk Score, and the Perinatal Risk Inventory. Associations were analyzed using Fisher's exact test, Spearman's correlation was used for ordinal variables, and backward stepwise logistic regression was used to identify predictor variables for the assessments.

RESULTS

The findings indicated a high prevalence of normal (41%) and poor (52%) repertoire patterns during the writhing period. While no significant associations were found between the three assessments, a slight approximation emerged between dysmorphic traits and patterns (p = 0.053). Furthermore, an extended period of ventilation correlated with a higher likelihood of developing a cramped synchronized pattern and there was a correlation between both risk factor-based tools (p < 0.001).

CONCLUSIONS

This research enhances our understanding of the early impact on general movement assessments in moderate-late preterm infants. While no clear relationship emerged between general movement assessment and risk factor-based tools, there was a subtle connection noted with dysmorphic traits. A longer ventilation duration was linked to a higher risk of developing cramped synchronized patterns.

Prenatal and perinatal factors associated with neonatal neurobehavioral profiles in the ECHO Program

BACKGROUND

Single-cohort studies have identified distinct neurobehavioral profiles that are associated with prenatal and neonatal factors based on the NICU Network Neurobehavioral Scale (NNNS). We examined socioeconomic, medical, and substance use variables as predictors of NNNS profiles in a multi-cohort study of preterm and term-born infants with different perinatal exposures.

METHODS

We studied 1112 infants with a neonatal NNNS exam from the Environmental influences on Child Health Outcomes (ECHO) consortium. We used latent profile analysis to characterize infant neurobehavioral profiles and generalized estimating equations to determine predictors of NNNS profiles.

RESULTS

Six distinct neonatal neurobehavioral profiles were identified, including two dysregulated profiles: a hypo-aroused profile (16%) characterized by lethargy, hypotonicity, and nonoptimal reflexes; and a hyper-aroused profile (6%) characterized by high arousal, excitability, and stress, with low regulation and poor movement quality. Infants in the hypo-aroused profile were more likely to be male, have younger mothers, and have mothers who were depressed prenatally. Infants in the hyper-aroused profile were more likely to be Hispanic/Latino and have mothers who were depressed or used tobacco prenatally.

CONCLUSIONS

We identified two dysregulated neurobehavioral profiles with distinct perinatal antecedents. Further understanding of their etiology could inform targeted interventions to promote positive developmental outcomes.

IMPACT

Prior research on predictors of neonatal neurobehavior have included single-cohort studies, which limits generalizability of findings. In a multi-cohort study of preterm and term-born infants, we found six distinct neonatal neurobehavioral profiles, with two profiles being identified as dysregulated. Hypo- and hyper-aroused neurobehavioral profiles had distinct perinatal antecedents. Understanding perinatal factors associated with dysregulated neurobehavior could help promote positive developmental outcomes.

Diagnostic accuracy of the Hammersmith Neonatal Neurological Examination in predicting motor outcome at 12 months for infants born very preterm

AIM

To evaluate the predictive validity of the Hammersmith Neonatal Neurological Examination (HNNE) performed early (at 32 weeks postmenstrual age) and at term-equivalent age (TEA) for 12-month motor outcomes in infants born very preterm.

METHOD

This was a diagnostic study using data from a prospective birth cohort. A total of 104 infants born preterm at less than 31 weeks gestational age (males n = 61; mean = 28 weeks 1 day [SD 1 week 6 days], range 23 weeks 1 day-30 weeks 6 days) underwent HNNE early and at TEA, which were scored by comparison with term data. Motor outcomes at 12 months corrected age were determined using the Bayley Scales of Infant and Toddler Development, Third Edition (scores ≤85). Cut-off points were determined using receiver operating characteristic curves.

RESULTS

Sixteen (15%) infants born preterm had motor impairment at 12 months corrected age. The HNNE total score cut-off points with the best combination of sensitivity and specificity at early and TEA assessments were 15.2 or lower (sensitivity 77%, 95% confidence interval [CI] = 46%-95%; specificity 74%, 95% CI = 63%-83%) and 23.5 or lower (sensitivity 67%, 95% CI = 38%-88%; specificity 66%, 95% CI = 54%-76%) respectively. The most predictive subscale at the early assessment was reflexes (sensitivity 86%, 95% CI = 57%-98%; specificity 62%, 95% CI = 51%-72%; cut-off point ≤3); at TEA, it was spontaneous movements (sensitivity 73%, 95% CI = 45%-92%; specificity 60%, 95% CI = 48%-70%; cut-off point ≤2).

INTERPRETATION

The HNNE provides moderate predictive accuracy for motor outcome at 12 months corrected age in infants born very preterm. Although modest at both time points, early assessment had stronger predictive ability for motor outcomes than TEA when scored using term data, highlighting the value of performing the HNNE earlier in the neonatal period. Performing HNNE earlier may assist risk stratification when planning follow-up services.

Rewarming rate of hypothermic neonates in a low-resource setting: a retrospective single-center study

Background

Hypothermic neonates need to be promptly rewarmed but there is no strong evidence to support a rapid or a slow pace of rewarming. This study aimed to investigate the rewarming rate and its associations with clinical outcomes in hypothermic neonates born in a low-resource setting.

Methods

This retrospective study evaluated the rewarming rate of hypothermic inborn neonates admitted to the Special Care Unit of Tosamaganga Hospital (Tanzania) in 2019-2020. The rewarming rate was calculated as the difference between the first normothermic value (36.5-37.5°C) and the admission temperature, divided by the time elapsed. Neurodevelopmental status at 1 month of age was assessed using the Hammersmith Neonatal Neurological Examination.

Results

Median rewarming rate was 0.22°C/h (IQR: 0.11-0.41) in 344/382 (90%) hypothermic inborn infants, and was inversely correlated to admission temperature (correlation coefficient -0.36, p < 0.001). Rewarming rate was not associated with hypoglycemia (p = 0.16), late onset sepsis (p = 0.10), jaundice (p = 0.85), respiratory distress (p = 0.83), seizures (p = 0.34), length of hospital stay (p = 0.22) or mortality (p = 0.17). In 102/307 survivors who returned at follow-up visit at 1 month of age, rewarming rate was not associated with a potential correlate of cerebral palsy risk.

Conclusions

Our findings did not show any significant association between rewarming rate and mortality, selected complications or abnormal neurologic exam suggestive of cerebral palsy. However, further prospective studies with strong methodological approach are required to provide conclusive evidence on this topic.

Bronchopulmonary dysplasia and neurobehavioural outcomes at birth and 2 years in infants born before 30 weeks

OBJECTIVE

To identify neurobehavioural risks in preterm infants with bronchopulmonary dysplasia (BPD) prior to hospital discharge.

DESIGN AND PATIENTS

Longitudinal study of 676 newborns born before 30 weeks of gestation.

SETTING

Nine university NICUs affiliated with six universities. All were Vermont Oxford Network (VON) participants.

PATIENTS AND INTERVENTIONS

Infants were enrolled in the Neonatal Neurobehavior and Outcomes in Very Preterm Infants Study from April 2014 to June 2016. Prospective medical record reviews, VON definitions and criteria, and maternal interviews were used to collect maternal and neonatal medical variables and socioenvironmental data.

MAIN OUTCOME MEASURES

NICU Network Neurobehavioral Scale (NNNS) at the time of hospital discharge; Bayley Scales of Infant and Toddler Development, Third Edition (Bayley-III) and Gross Motor Function Classification System at 2 years' corrected age.

RESULTS

Infants with moderate/severe BPD were less attentive (Wald χ2 9.68, p=0.008), more lethargic (Wald χ2 9.91, p=0.007), with increased non-optimal reflexes (Wald χ2 7.37, p=0.025). Infants with moderate/severe BPD were more likely to have Bayley-III language and motor scores <85 (adjusted OR (aOR) 1.74, 95% CI 1.06 to 2.85, and aOR 2.06, 95% CI 1.10 to 3.85). Infants with both moderate/severe and mild BPD were more likely to have a cerebral palsy diagnosis (aOR 2.96, 95% CI 1.34 to 6.54, and aOR 2.81, 95% CI 1.32 to 5.99).

CONCLUSIONS

BPD severity presents risks for poor neurodevelopment at NICU discharge and at age 2 years. Early identification of poorly regulated behaviour can provide critical information for early preventive and targeted interventions with potential to improve long-term outcomes.

Neurobehavior in very preterm infants with low medical risk and full-term infants

OBJECTIVE

To describe differences in neurobehavior among very preterm infants with low medical risk at term equivalent age and full-term infants.

STUDY DESIGN

One-hundred eighty-six (136 infants born ≤32 weeks gestation with low medical risk at term equivalent age and 50 full-term infants within 4 days of birth) had standardized neurobehavioral assessments. Low medical risk was defined by ventilation <10 days and absence of significant brain injury, necrotizing enterocolitis, patent ductus arteriosus, and retinopathy of prematurity.

RESULTS

Very preterm infants with low medical risk at term equivalent age demonstrated more sub-optimal reflexes (p < 0.001; ß = 1.53) and more stress (p < 0.001; ß = 0.08) on the NICU Network Neurobehavioral Scale compared to their full-term counterparts. Very preterm infants with low medical risk also performed worse on the Hammersmith Neonatal Neurological Examination (p = 0.005; ß = -3.4).

CONCLUSION

Very preterm infants at term equivalent age continue to demonstrate less optimal neurobehavior compared to full-term infants.

Development of a new scoring method in the neurofunctional assessment of preterm infants

Infants born preterm are at high risk of presenting neurodevelopmental delay. The Neurofunctional Assessment (NFA) describes infants' neurodevelopment through the evaluation of six different domains. This study aimed to evaluate how, in a cohort of preterm infants, each NFA domain assessed at 3 months of corrected age (CA) was associated with neurodevelopment at 2 years of CA using the Griffiths Mental Developmental Scales Extended Revised (GMDS-ER). In addition, by introducing the NFA complexity score (CS), the study aimed to define a threshold that can help clinicians discriminate infants at higher risk of later neurodevelopmental delay. We conducted an observational, longitudinal study including 211 preterm infants. At 3 months of CA, infants who had normal scores in each domain showed a significantly higher GMDS-ER global quotient (GQ) at 2 years of CA. In addition, linear model results showed a significant negative relationship between the NFA CS and 2-year GMDS-ER GQ (estimate: - 0.27; 95% CI - 0.35, - 0.20; p value < 0.001). Each 10-point increase in the NFA CS was associated with an average 2.7-point decrease in the GMDS GQ. These results highlight how the NFA domains and NFA CS are compelling instruments for the early identification of children at risk for long-term adverse outcomes.

Neurological examination at 32-weeks postmenstrual age predicts 12-month cognitive outcomes in very preterm-born infants

BACKGROUND

To determine the diagnostic accuracy of Hammersmith Neonatal Neurological Examination (HNNE) at 30-32 weeks postmenstrual age (PMA, 'Early') and term equivalent age (TEA) in infants born <31 weeks PMA to predict cognitive outcomes at 12 months corrected age (CA).

METHODS

Prospective cohort study of 119 infants (73 males; median 28.4 weeks gestational age at birth) who underwent Early and TEA HNNE. At 12 months CA, 104 participants completed Bayley Scales of Infant and Toddler Development, 3rd Edition, (Bayley-III). Optimum cut-off points for each HNNE subscale were determined to establish diagnostic accuracy for predicting adverse cognitive outcomes on the Bayley-III Cognitive Composite Scale (≤85).

RESULTS

The best diagnostic accuracy for HNNE total score at 30-32 weeks PMA predicting cognitive impairment occurred at cut-off ≤16.7 (sensitivity (Se) = 71%, specificity (Sp) = 51%). The Abnormal Signs subscale demonstrated the best balance of sensitivity/specificity combination (Se = 71%, Sp = 71%; cut-off ≤1.5). For HNNE at TEA, the total score at cut-off ≤24.5 had Se = 71% and Sp = 47% for predicting cognitive impairment. The Tone Patterns subscale demonstrated the strongest diagnostic accuracy at TEA (Se = 71%, Sp = 63%; cut-off ≤3).

CONCLUSIONS

Early and TEA HNNE demonstrated moderate diagnostic accuracy for cognitive outcomes at 12-months CA in infants born <31 weeks gestational age.

CLINICAL TRIAL REGISTRATION

Australian New Zealand Clinical Trials Registry; Trial Registration Number: ACTRN12613000280707; web address of trial: http://www.ANZCTR.org.au/ACTRN12613000280707.aspx .

IMPACT

Early Hammersmith Neonatal Neurological Examination (HNNE) assessment at 30-32 weeks postmenstrual age has moderate diagnostic accuracy for cognitive outcomes at 12 months corrected age in infants born <31 weeks gestation. Early HNNE at 30-32 weeks has stronger predictive validity than HNNE at term equivalent age. Early HNNE may provide an early marker for risk-stratification to optimise the planning of post-discharge support and follow-up services for infants born preterm.

Assessing the Utility of Neonatal Screening Assessments in Early Diagnosis of Cerebral Palsy in Preterm Infants

Background: Early diagnosis of cerebral palsy (CP) in high-risk infants is possible at 3−4 months’ corrected age (CA) using standardised assessments. Aim: To assess the utility of neonatal screening assessments—writhing general movements (GMs) and the Hammersmith Neonatal Neurological Examination (HNNE)—to predict CP/high-risk status at 3−4 months’ CA in extremely preterm infants. Methods: Retrospective cohort study of high-risk preterm infants (born < 29 weeks’ gestation and/or birth weight < 1000 g) attending an Early Neurodevelopment Clinic. Data from neonatal assessments were compared with CP/high-risk diagnosis at 3−4 months’ CA, fidgety GMs, and Hammersmith Infant Neurological Examinations (HINE) using logistic regression, linear regression, and Spearman rank correlation. Results: Two hundred and two preterm infants (median gestation age at birth 27.3 (IQR 25.4−28.3) weeks, mean birth weight 870.3 (SD 248.4) grams) were included. A total of 26 (12.8%) infants received early CP/high-risk diagnoses at 3−4 months’ CA. A lower gestational age (GA) (OR = 0.78; p = 0.029, 95% CI [0.26, 0.97]) and abnormal writhing GMs (OR 1.56; p = 0.019, 95% CI [1.07, 2.27]) were predictive of CP/high-risk diagnosis. Although after adjustment for sex, GA, birth weight, and growth restriction, GA (aOR = 0.67; p = 0.068, 95% CI [0.44, 1.03]) and writhing GMs (aOR = 1.44; p = 0.087, 95% CI [0.95, 2.20]) were not significant, a strong trend still persisted. The HNNE scores significantly correlated with both the HINE evaluation (rs = 0.43, p < 0.001, 95% CI [0.31, 0.56]) and fidgety GMs (rs = −0.10, p = 0.012, 95% CI [−0.32, −0.04]). Linear regression confirmed the HNNE was highly predictive of the HINE (correlation coefficient 0.82; p < 0.001, 95% CI [0.48, 1.15]). Writhing GMs did not significantly correlate with either fidgety GMs (p = 0.723, 95% CI [−0.12, 0.17]) or the HINE (p = 0.173, 95% CI [−0.24, 0.04]). Conclusions: Abnormal writhing GMs in the neonatal period were non-significantly associated with early CP/high-risk diagnoses in extremely preterm infants in a multivariate analysis. Additionally, the HNNE significantly correlated with both fidgety GMs and the HINE.

Relationship between Admission Temperature and Risk of Cerebral Palsy in Infants Admitted to Special Care Unit in a Low Resource Setting: A Retrospective Single-Center Study

Background: Deviations from normothermia affect early mortality and morbidity, but the impact on neurodevelopment of the survivors is unclear. We aimed to investigate the relationship between neonatal temperature at admission and the risk of cerebral palsy (CP) at one month of age in a low-resource setting. Methods: This retrospective study included all inborn neonates admitted to the Special Care Unit of Tosamaganga Hospital (Tanzania) between 1 January 2019 and 31 December 2020. The neurological examination at one month of age was performed using the Hammersmith method. The relationship between the admission temperature and the risk of CP was investigated using logistic regression models, with temperature modeled as the non-linear term. Results: High/moderate risk of CP was found in 40/119 (33.6%) of the neonates at one month of age. A non-linear relationship between the admission temperature and moderate/high risk of CP at one month of age was found. The lowest probability of moderate/high risk of CP was estimated at admission temperatures of between 35 and 36 °C, with increasing probability when departing from such temperatures. Conclusions: In a low-resource setting, we found a U-shaped relationship between the admission temperature and the risk of CP at one month of life. Expanding the analysis of the follow-up data to 12–24 months of age would be desirable in order to confirm and strengthen such findings.

"The Value of Clinical Examination in Preterm Newborns after Neonatal Sepsis: A Cross-sectional Observational Study."

BACKGROUND

Neonatal sepsis is an important risk factor for lesions in the brain of preterm newborns (PTNB) and the most effective strategies to minimize its deleterious effects are early detection and intervention.

AIM

To investigate the presence of neurological abnormalities in PTNBs after neonatal sepsis.

METHODS

This was a prospective cross-sectional study with 100 PTNBs selected at random, 50 of the study group (sepsis) and 50 of the control group (non-sepsis). The neurological evaluation protocol adopted was the Hammersmith Neonatal Neurological Examination (HNNE).

RESULTS

The PTNBs of the sepsis group had total HNNE scores lower than expected for normality in 86% of the cases, and the non-sepsis group in 26% (p < .001). Higher prevalence levels of altered scores in tone category (p < .001), tone patterns (p = .026), reflexes (p = .002), movements (p < .001), abnormal signs (p < .001) and behavior (p < .001).

CONCLUSION

The neurological dysfunctions after neonatal sepsis could be identified by clinical neonatal neurological evaluation.

A neonatal neuroNICU collaborative approach to neuromonitoring of posthemorrhagic ventricular dilation in preterm infants

Morbidity and mortality in prematurely born infants have significantly improved due to advancement in perinatal care, development of NeuroNICU collaborative multidisciplinary approaches, and evidence-based management protocols that have resulted from a better understanding of perinatal risk factors and neuroprotective treatments. In premature infants with intraventricular hemorrhage (IVH), the detrimental secondary effect of posthemorrhagic ventricular dilation (PHVD) on the neurodevelopmental outcome can be mitigated by surgical intervention, though management varies considerably across institutions. Any benefit derived from the use of neuromonitoring to optimize surgical timing and technique stands to improve neurodevelopmental outcome. In this review, we summarize (1) the approaches to surgical management of PHVD in preterm infants and outcome data; (2) neuromonitoring modalities and the effect of neurosurgical intervention on this data; (3) our resultant protocol for the monitoring and management of PHVD. In particular, our protocol incorporates cerebral near-infrared spectroscopy (NIRS) and transcranial doppler ultrasound (TCD) to better understand cerebral physiology and to enable the hypothesis-driven study of the management of PHVD. IMPACT: Review of the published literature concerning the use of near-infrared spectroscopy (NIRS) and a cerebral Doppler ultrasound to study the effect of cerebrospinal fluid drainage on infants with posthemorrhagic ventricular dilation. Presentation of our institution's evidence-based protocol for the use of NIRS and cerebral Doppler ultrasound to study the optimal neurosurgical treatment of posthemorrhagic ventricular dilation, an as yet inadequately studied area.

Relationships between early postnatal cranial ultrasonography linear measures and neurobehaviour at term-equivalent age in infants born <30 weeks' gestational age

BACKGROUND

The relationship between early postnatal brain development and neurobehaviour at term-equivalent age (TEA) remains uncertain.

AIM

We aimed to explore relationships between early postnatal cranial ultrasonography (cUS) linear measures of brain size and brain growth with neurobehaviour at TEA in infants born <30 weeks' gestational age (GA).

STUDY DESIGN

Prospective observational cohort study.

SUBJECTS

137 infants born <30 weeks' GA without major brain injury on neonatal cUS.

OUTCOME MEASURES

Neurobehaviour at TEA assessed using the General Movements Assessment (GMA) and Hammersmith Neonatal Neurological Examination (HNNE).

RESULTS

The GMA was administered in 115/137 (84%) infants; 80 (70%) presented with abnormal general movements (GMs) (79 poor repertoire, 1 cramped synchronised). The HNNE was assessed in 106/137 (77%) infants; 52 (49%) had a suboptimal total score. With respect to brain size, larger measures of the corpus callosum length (CCL) and right anterior horn width (AHW) at 1-month were related to lower risk of abnormal GMs, and larger measures of the biparietal diameter at 1-week and 2-months were related to lower risk of a suboptimal HNNE. As for brain growth, increases of the CCL and transcerebellar diameter between birth and 1-month, and left and right AHWs between 1- and 2-months, were related to lower risk of abnormal GMs.

CONCLUSION

Early postnatal brain size and brain growth were related to neurobehaviour at TEA in infants born <30 weeks' GA. This study provides preliminary evidence for the prognostic utility of early postnatal cUS linear measures as potential markers of neurodevelopment in later childhood.

Impaired Oligodendrocyte Development Following Preterm Birth: Promoting GABAergic Action to Improve Outcomes

Preterm birth is associated with poor long-term neurodevelopmental and behavioral outcomes, even in the absence of obvious brain injury at the time of birth. In particular, behavioral disorders characterized by inattention, social difficulties and anxiety are common among children and adolescents who were born moderately to late preterm (32-37 weeks' gestation). Diffuse deficits in white matter microstructure are thought to play a role in these poor outcomes with evidence suggesting that a failure of oligodendrocytes to mature and myelinate axons is responsible. However, there remains a major knowledge gap over the mechanisms by which preterm birth interrupts normal oligodendrocyte development. In utero neurodevelopment occurs in an inhibitory-dominant environment due to the action of placentally derived neurosteroids on the GABA_A receptor, thus promoting GABAergic inhibitory activity and maintaining the fetal behavioral state. Following preterm birth, and the subsequent premature exposure to the ex utero environment, this action of neurosteroids on GABA_A receptors is greatly reduced. Coinciding with a reduction in GABAergic inhibition, the preterm neonatal brain is also exposed to ex utero environmental insults such as periods of hypoxia and excessive glucocorticoid concentrations. Together, these insults may increase levels of the excitatory neurotransmitter glutamate in the developing brain and result in a shift in the balance of inhibitory: excitatory activity toward excitatory. This review will outline the normal development of oligodendrocytes, how it is disrupted under excitation-dominated conditions and highlight how shifting the balance back toward an inhibitory-dominated environment may improve outcomes.

Gestational Age-Specific Distribution of the Hammersmith Neonatal Neurological Examination Scores Among Low-Risk Neonates in Ghana

OBJECTIVE

To describe gestational age-specific distribution of scores for the Hammersmith Neonatal Neurological Examination (HNNE) up to 48 h after birth in a low-risk, term-born, single-center sample in Ghana.

STUDY DESIGN

This is a nested substudy of a larger prospective study (IMPRINT: Impact of Malaria in Pregnancy on Infant Neurodevelopment) comprising 140 low-risk, term-born neonates at Korle Bu Teaching Hospital in Accra, Ghana, between November 2018 and February 2019. The sample was stratified into three gestational age groups: early-term (37 + 0-38 + 6, weeks + days; n = 61), full-term (39 + 0-40 + 6, weeks + days; n = 52), and late/post-term (41 + 0-42 + 6, weeks + days; n = 27). Neonates were administered the 34-item HNNE by trained physicians. As per the original British scoring system, raw scores for the Ghanaian sample were plotted and scores > 10th centile were assigned a score of 1, 5th-10th centile 0.5, and < 5th centile 0.

RESULTS

The range of raw scores for 16/34 HNNE items varied with gestational age. Specifically, 100% (7/7), 50% (5/10), 33% (1/3), 33% (1/3), 20% (1/5), and 14% (1/7) of items within the orientation and behavior, tone, abnormal signs/patterns, movements, tone patterns, and reflexes subdomain, respectively showed a different distribution of scores above the 10th centile across the three gestational age groups.

CONCLUSION

Differences in gestational age-specific results within our sample in comparison to the original British sample could be, albeit unlikely, due to misclassification of gestational age, unmeasured maternal or fetal morbidity, or perhaps more likely, variation in testing or test conditions, or some combination of these. Genetic variation in neurological development is also a possibility. Further research is warranted to determine the reasons for differences. Our findings highlight the need to determine the accuracy and reliability of standardized neurologic assessments in predicting neurodevelopmental risk for infants in low- and middle-income countries.

Early Neurological Assessment and Long-Term Neuromotor Outcomes in Late Preterm Infants: A Critical Review

Background and Objectives: Late preterm (LP) infants (born between 34 and 36 weeks of gestational age) are considered at higher risk of neonatal morbidities, mortality, and neurological impairments than full-term born infants (FT). The aim of this study was to provide a critical review of the literature outlining the different aspects of neurological function reported both in the neonatal period and in the follow up of late preterm infants. Materials and Methods: A comprehensive search of the MEDLINE, Embase, PsycINFO, and CINAHL electronic databases was made, using the following search terms: ‘Late preterm infants’, ‘Near term infants’, ‘neurological assessment’, ‘neurological outcome’, ‘neuromotor outcome’, cerebral palsy’, ‘CP’, ‘motor impairment’, including all the studies reporting clinical neurological assessment of LP (including both neonatal period and subsequent ages). Results: A total of 35 articles, comprising 301,495 children, were included as fulfilling the inclusion criteria: ten reported neonatal neurological findings, seven reported data about the first two years after birth, eighteen reported data about incidence of CP and motor disorder during the infancy. Results showed a more immature neurological profile, explored with structured neurological assessments, in LP infants compared with FT infants. The LP population also had a higher risk of developing cerebral palsy, motor delay, and coordination disorder. Conclusion: LP had a higher risk of neurological impairments than FT infants, due to a brain immaturity and an increased vulnerability to injury, as the last weeks of gestational age are crucial for the development of the brain.

Associations of Neonatal Noncardiac Surgery with Brain Structure and Neurodevelopment: A Prospective Case-Control Study

OBJECTIVE

To examine the associations of neonatal noncardiac surgery with newborn brain structure and neurodevelopment at 2 years of age.

STUDY DESIGN

Infants requiring neonatal noncardiac surgery for congenital diaphragmatic hernia, esophageal atresia, or anterior abdominal wall defect were compared with infants who did not require surgery, matched for sex, gestation at birth, and postmenstrual age at magnetic resonance imaging. Cerebral magnetic resonance imaging was performed at a mean (SD) postmenstrual age of 41.6 (1.7) weeks. Images were assessed qualitatively for brain maturation and injury and quantitatively for measures of brain size, cerebrospinal fluid spaces, and global abnormality. Neurodevelopment was then assessed at 2 years using the Bayley Scales of Infant and Toddler Development, 3rd edition.

RESULTS

Infants requiring surgery (n = 39) were 5.9 times (95% CI, 1.9-19.5; P < .01) more likely to have delayed gyral maturation and 9.8 times (95% CI, 1.2-446; P = .01) more likely to have white matter signal abnormalities compared with controls (n = 39). Cases were more likely to have higher global abnormality scores, smaller biparietal diameters, and larger ventricular sizes than controls. Infants who had surgery had lower mean composite scores in the language (mean difference, -12.5; 95% CI, -22.4 to -2.7) and motor domains (mean difference, -13.4; 95% CI, -21.1 to -5.6) compared with controls.

CONCLUSIONS

Infants requiring neonatal noncardiac surgery have smaller brains with more abnormalities compared with matched controls and have associated neurodevelopmental impairment at 2 years of age. Prospective studies with preoperative and postoperative imaging would assist in determining the timing of brain injury.

Brain structure and neurological and behavioural functioning in infants born preterm

AIM

To examine: (1) relationships between brain structure, and concurrently assessed neurological and behavioural functioning, in infants born preterm at term-equivalent age (TEA; approximately 38-44wks); and (2) whether brain structure-function relationships differ between infants born very (24-29wks) and moderate-late (32-36wks) preterm.

METHOD

A total of 257 infants (91 very preterm, 166 moderate-late preterm; 120 males, 137 females) had structural magnetic resonance imaging (MRI) and neurological and behavioural assessments (Prechtl's general movements assessment, Neonatal Intensive Care Unit Network Neurobehavioral Scale [NNNS] and Hammersmith Neonatal Neurological Examination [HNNE]). Two hundred and sixty-three infants (90 very preterm, 173 moderate-late preterm; 131 males, 132 females) had diffusion MRI and assessments. Associations were investigated between assessment scores and global brain volumes using linear regressions, regional brain volumes using Voxel-Based Morphometry, and white matter microstructure using Tract-Based Spatial Statistics.

RESULTS

Suboptimal scores on some assessments were associated with lower fractional anisotropy and/or higher axial, radial, and mean diffusivities in some tracts: NNNS attention and reflexes, and HNNE total score and tone, were associated with the corpus callosum and optic radiation; NNNS quality of movement with the corona radiata; HNNE abnormal signs with several major tracts. Brain structure-function associations generally did not differ between the very and moderate-late preterm groups.

INTERPRETATION

White matter microstructural alterations may be associated with suboptimal neurological and behavioural performance in some domains at TEA in infants born preterm. Brain structure-function relationships are similar for infants born very preterm and moderate-late preterm.

WHAT THIS PAPER ADDS

Brain volume is not related to neurological/behavioural function in infants born preterm at term. White matter microstructure is related to some neurological/behavioural domains at term. Brain-behaviour relationships are generally similar for infants born very preterm and moderate-late preterm.

General spontaneous movements in preterm infants differentiated by post-conceptional ages

AIM

The aim of the study was to assess general spontaneous motor development in the neonatal phase in groups of neonatal high-risk preterm infants who were differentiated by post-conceptional (PCo) age until term age.

METHOD

The sample included 54 preterm infants (<32 weeks of gestational age) with low birthweight and neurological injuries of both sexes. The General Movements Assessment (GMA) was used to evaluate motor development from 30 to 40 weeks of PCo age, using the General Movements Optimality Score (GMOS). Between-group and within-group comparisons were performed.

RESULTS

Significant differences in GMOS scores and the upper extremities score, specifically in the neck and trunk, were found between 30 and 33 weeks, 34 and 36 weeks, and 38 and 40 weeks of PCo age. Preterm infants had gradually higher GMOSs from 30 weeks of PCo age to term age (38-40 weeks of PCo age). No significant differences in general movements were found between 30 and 33 and 34 and 36 weeks of PCo age.

CONCLUSION

The preterm infants presented poor spontaneous motor movements, assessed by the GMOS, but gradual improvement was observed from 30 weeks of PCo age until term age.

Neurobehavior of preterm infants from 32 to 48 weeks post-menstrual age

AIM

Evaluate prospectively the neurobehavior of preterm infants (PT).

STUDY DESIGN

Cohort of PT (gestational age(GA) <32weeks), evaluated biweekly from 32 to 48 weeks post-menstrual age (PMA) by NICU Network Neurobehavioral Scale (NNNS). Scores were compared by repeated Measures ANOVA. Scores of PT were compared to those of full-term infants, matched for gender by ANOVA.

RESULTS

39 PT (mean ± SD: GA 29.2 ± 2.0 weeks; birthweight 1100 ± 331g) were studied. As PMA progressed, PT showed increasing scores in habituation, attention, arousal, regulation, maneuvers for orientation, quality of movements and hypertonicity, and decreasing scores in excitability, lethargy, non-optimal reflexes, asymmetry, hypotonicity, and signs of stress/withdrawal. At 40 weeks PMA, PT were similar to term neonates assessed in the first days of life, except for less habituation, regulation capacity and excitability, and more hypotonia.

CONCLUSION

At 40 weeks PMA, PT reached the performance of full-term neonates evaluated in the first days of life in most neurobehavior domains.

Evaluation of neurological behaviour in late-preterm newborn infants using the Hammersmith Neonatal Neurological Examination

AIM

We hypothesise that clinically well late-preterm infants (LPI) (34⁺⁰ -36⁺⁶ weeks) are neurologically more immature than their term counterparts, and this immaturity persists even when these infants reach term-corrected age (TCA). The primary aim of our study was to characterise and contrast the neurodevelopmental profile of well LPI with full-term infants (FTI) (39⁺⁰ -41⁺⁶ weeks) using the Hammersmith Neonatal Neurological Examination (HNNE). Our secondary aim was to obtain local reference ranges for the 34 items in the HNNE in an Asian-dominant population.

METHODS

LPI were assessed at two time points: 12-72 h of life and at TCA of 39⁺⁰ -41⁺⁶ weeks, while FTI were assessed at 12-72 h of life using the HNNE. Each of the 34 items on the HNNE was assigned an optimality score (OS) of 0, 0.5 or 1, totalling up to 34. A quantitative comparison of the neurobehavioral patterns was made using two-sample t-tests.

RESULTS

A total of 212 infants (79 LPI and 133 FTI) were recruited. Mean OSs for LPI and FTI at birth were (25.11 ± 3.36)/34 and (31.19 ± 1.50)/34, respectively, with a mean difference of 6.08 (P value <0.0001). The mean OS for LPI on reaching TCA was (28.91 ± 2.30)/34, with a mean difference of 2.28 (P value <0.0001). Reference OSs for the 34 items on the HNNE were also obtained.

CONCLUSION

LPI are more immature than their term counterparts even on reaching TCA, with discrepancies most apparent in 'tone' and 'movement'. We provide reference OSs of 34 items in the HNNE for infants in an Asian-dominant population.

Spontaneous movements in the first four months of life: An accelerometric study in moderate and late preterm infants

BACKGROUND

Moderate preterm infants (MPI) and late preterm infants (LPI) account for the majority of children born preterm. Up to 5% of MPI and LPI are estimated to manifest neurodevelopmental impairments. However, information about normal early motor development in these patients is lacking.

AIM

To find characteristic patterns for motor development in the first four months of life among MPI and LPI without risk factors for developmental impairment by using accelerometry of spontaneous movements.

STUDY DESIGN

Prospective and observational study.

SUBJECTS

Twenty-three MPI and LPI (9 female, 14 male) without known risk factors for neurodevelopmental impairment were included in this study. Spontaneous movements were measured by accelerometry at the time of hospital discharge (mean: 36.6wks postmenstrual age (PMA)) and at the corrected age of three months (mean: 53.0wks PMA).

OUTCOME MEASURES

Motor development was described by analyzing 36 parameters calculated from the acceleration signal. Normal neurodevelopmental outcome was confirmed by Bayley Scales of Infant Development at the corrected age of two years.

RESULTS

Statistically significant differences (p < 0.05) between the two measurements could be shown in 26 out of the 36 parameters. Striking changes in motor development were an increase in acceleration and variability of the spontaneous movements, the main criterion for analyzing spontaneous movements. Furthermore, the regularity of spontaneous movements increased significantly.

CONCLUSION

Characteristic patterns of normal motor development in MPI and LPI can be identified and provide a basis for future investigations aiming at the early detection of abnormal motor development for this specific patient group.

The Relationship Between Clinical Imaging and Neurobehavioral Assessment in Posthemorrhagic Ventricular Dilation of Prematurity

Introduction: Neonatal intraventricular hemorrhage (IVH) and subsequent posthemorrhagic ventricular dilation and hydrocephalus of prematurity are associated with brain injury and neurodevelopmental impairment in the preterm population. Neuroimaging assesses cerebral injury and guides neurosurgical intervention; however, the relationship of head ultrasound (HUS) and magnetic resonance imaging (MRI) parameters to neonatal exams in this group has not been well described. The NICU Network Neurobehavioral Scale (NNNS) is a reproducible, highly reliable battery with motor and cognitive domain scores. Objective: To evaluate the relationship between neonatal neurobehavioral findings on the NNNS and measures of ventricular dilation and associated brain injury on HUS and MRI. Materials and Methods: Neonates with IVH and ventricular dilatation with and without posthemorrhagic hydrocephalus were enrolled. NNNS exams were performed at approximately term age equivalent. HUS indices were measured on the last HUS before initial neurosurgical procedure or that with worst ventriculomegaly if no intervention. The posterior fossa was assessed with MRI at term. Descriptive statistics including medians, interquartile ranges, means, and percentages were performed. Correlations were estimated using Pearson's method. Results: 28 patients had NNNS and HUS, and 18 patients also had an MRI. Ventricle size measures for the cohort were significantly above normal. Motor and cognitive subscores on the NNNS exam varied from established baseline scores for postmenstrual age. Children who required neurosurgical intervention had higher ventricle/brain ratios and worse NNNS habituation scores. Ventricle sizes were modestly correlated with motor abnormalities (0.24-0.59); larger anterior horn width correlated with nonoptimal reflexes, hypertonicity and hypotonicity. Ventricle sizes were modestly correlated with cognitive scores (-0.44 to 0.27); larger ventricular index correlated with worse attention. Periventricular hemorrhagic infarction correlated with worse habituation. Conclusion: For this cohort of preterm infants with IVH, surgical intervention for posthemorrhagic hydrocephalus correlated with both larger degrees of ventriculomegaly and worse NNNS exams. Findings on both HUS and MRI correlated with motor and cognitive abnormalities on neonatal neurobehavioral exam, suggesting that larger neonatal ventricle sizes and white matter injury have detectable correlates on exam. The NNNS exam provides important additional information when assessing posthemorrhagic ventricular dilation and hydrocephalus of prematurity.

Late preterm births: New insights from neonatal neuroimaging and neurobehaviour

With increasing evidence of neurodevelopmental problems faced by late preterm children, there is a need to explore possible underlying brain structural changes. The use of brain magnetic resonance imaging has provided insights of smaller and less mature brains in infants born late preterm, associated with developmental delay at 2 years. Another useful tool in the newborn period is neurobehavioural assessment, which has also been shown to be suboptimal in late preterm infants compared with tern infants. Suboptimal neurobehaviour is also associated with poorer 2-year neurodevelopment in late preterm infants. More research into these tools will provide a better understanding of the underlying processes of developmental deficits of late preterm children. The value of their role in clinical care remains to be determined.

Maturation of auditory brainstem response in early term infants at 6 weeks and 9 months

BACKGROUND

Emerging evidence indicates that infants who were born between 37 and 38 weeks of gestation are at higher risk of adverse long-term neurodevelopmental outcomes. Yet little is known about the auditory neural maturation during the first year of their life.

AIM

To compare the development of auditory brainstem response in early term (ET, 37-38 weeks gestational age, GA) and full term (FT, 39-41 weeks GA) infants.

METHODS

126 infants received ABR testing at 6 weeks. 107 of them returned for the second assessment at 9 months, among which, 93 completed the ABR recordings. Comparison of the ABR variables were made depending on gestational age.

RESULTS

Analysis of covariance (ANCOVA) was used to identify the differences in ABR outcomes between two groups. After controlling for confounders, latencies for wave III, V and I-III, III-V and I-V intervals were prolonged in ET group compared with FT group at 6 weeks (all p<0.03). ABR parameters of both groups developed as the infants got older. At 9 months, ET infants remain showing the longer wave V latency and I-V interval (all p < 0.02) than FT infants.

CONCLUSION

During early postnatal life, ET has a different pattern of functional auditory brainstem development comparing with FT infants. The prolonged auditory conduction time suggests less mature of the central auditory system in ET infants before 9 months.

NICU Network Neurobehavioral Scale: 1-month normative data and variation from birth to 1 month

BackgroundThe Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS) is a standardized method for infant neurobehavioral assessment. Normative values are available for newborns, but the NNNS is not always feasible at birth. Unfortunately, 1-month NNNS normative data are lacking.AimsTo provide normative data for the NNNS examination at 1 month and to assess birth-to-one-month changes in NNNS summary scores.Study designThe NNNS was administered at birth and at 1 month within a longitudinal prospective study design.SubjectsA cohort of 99 clinically healthy full-term infants were recruited from a well-child nursery.Outcome measuresBirth-to-1-month NNNS variations were evaluated and the association of neonatal and sociodemographic variables with the rate of change of NNNS summary scores were investigated.Results and conclusionsNNNS scores from the 10th to the 90th percentile represent a range of normative performance at 1 month. A complex pattern of stability and change emerged comparing NNNS summary scores from birth to 1 month. Orienting, Regulation, and Quality of movements significantly increased, whereas Lethargy and Hypotonicity significantly decreased. Birth-to-1-month changes in NNNS performance suggest improvements in neurobehavioral organization. These data are useful for research purposes and for clinical evaluation of neurobehavioral performance in both healthy and at-risk 1-month-old infants.

Continuum of neurobehaviour and its associations with brain MRI in infants born preterm

BACKGROUND

Infants born very preterm (VPT) and moderate-to-late preterm (MLPT) are at increased risk of long-term neurodevelopmental deficits, but how these deficits relate to early neurobehaviour in MLPT children is unclear. The aims of this study were to compare the neurobehavioural performance of infants born across three different gestational age groups: preterm <30 weeks' gestational age (PT<30); MLPT (32-36 weeks' gestational age) and term age (≥37 weeks' gestational age), and explore the relationships between MRI brain abnormalities and neurobehaviour at term-equivalent age.

METHODS

Neurobehaviour was assessed at term-equivalent age in 149 PT<30, 200 MLPT and 200 term-born infants using the Neonatal Intensive Care UnitNetwork Neurobehavioral Scale (NNNS), the Hammersmith Neonatal Neurological Examination (HNNE) and Prechtl's Qualitative Assessment of General Movements (GMA). A subset of 110 PT<30 and 198 MLPT infants had concurrent brain MRI.

RESULTS

Proportions with abnormal neurobehaviour on the NNNS and the HNNE, and abnormal GMA all increased with decreasing gestational age. Higher brain MRI abnormality scores in some regions were associated with suboptimal neurobehaviour on the NNNS and HNNE. The relationships between brain MRI abnormality scores and suboptimal neurobehaviour were similar in both PT<30 and MLPT infants. The relationship between brain MRI abnormality scores and abnormal GMA was stronger in PT<30 infants.

CONCLUSIONS

There was a continuum of neurobehaviour across gestational ages. The relationships between brain abnormality scores and suboptimal neurobehaviour provide evidence that neurobehavioural assessments offer insight into the integrity of the developing brain, and may be useful in earlier identification of the highest-risk infants.

Triadic interactions in families with preterm children: a comparative study with children born at term

The relationship between parents and infants born preterm is multifaceted and could present some relational patterns which are believed to predict psychological risk more than others. For example, insensitive parenting behavior has been shown to place very preterm children at greater risk of emotional and behavioral dysregulation. The main objective of this study was to compare the quality of family interactions in a sample of families with preterm children with one of the families with at-term children, exploring possible differences and similarities. The second aim of this research was to consider the associations among family interactions and parental empowerment, the child's temperament, parenting stress, and perceived social support. The sample consisted of 52 children and their families: 25 families, one with two preterm brothers with preterm children (mean 22.3 months, SD 12.17), and 26 families with children born at term (mean 22.2 months, SD 14.97). The Lausanne Trilogue Play procedure was administered to the two groups to assess the quality of their family interactions. The preterm group was also administered the Questionari Italiani del Temperamento, the Family Empowerment Scale, the Multidimensional Scale of Perceived Social Support, and the Parenting Stress Index - Short Form. Differences in the quality of family interactions emerged between the preterm and at-term groups. The preterm group showed significantly lower quality of family interactions than the at-term group. The parenting stress of both parents related to their parental empowerment, and maternal stress was also related to the partner's parental empowerment. Social support had a positive influence on parenting stress, with maternal stress also related to perceived social support from the partner, which underscores the protective role of the father on the dyad.

Preterm behavioral epigenetics: A systematic review

Behavioral epigenetics is revealing new pathways that lead individuals from early adversity exposures to later-in-life detrimental outcomes. Preterm birth constitutes one of the major adverse events in human development. Preterm infants are hospitalized in the Neonatal Intensive Care Unit (NICU) where they are exposed to life-saving yet pain-inducing procedures and to protective care. The application of behavioral epigenetics to the field of preterm studies (i.e., Preterm Behavioral Epigenetics, PBE) is rapidly growing and holds promises to provide valid insights for research and clinical activity. Here, the evidence of the epigenetic correlates of prenatal adversities, NICU-related environment and development of preterm infants is systematically reviewed. The findings suggest that a number of prenatal adverse (e.g., maternal depression and stress) and post-natal (e.g., NICU-related pain-related stress) events affect the developmental trajectories of preterm infants and children via epigenetic alterations of imprinted and stress-related genes. Nonetheless, the potential epigenetic vestiges of early care and protective interventions in NICU have not been investigated yet and this represents a fascinating challenge for future PBE research.

Neuropredictors of oromotor feeding impairment in 12month-old children

BACKGROUND

Feeding impairment is prevalent in children with neurodevelopmental issues. Neuroimaging and neurobehavioral outcomes at term are predictive of later neuromotor impairment, but it is unknown whether they predict feeding impairment.

AIMS

To determine whether neurobehavior and brain magnetic resonance imaging (MRI) at term predict oromotor feeding at 12 months in preterm and term-born children.

STUDY DESIGN

Prospective cohort study.

SUBJECTS

248 infants (97 born <30 weeks and 151 born at term) recruited at birth.

OUTCOME MEASURES

Neurobehavioral assessments (General Movements (GMA), Hammersmith Neonatal Neurological Examination (HNNE), Neonatal Intensive Care Unit Network Neurobehavioral Scale (NNNS)); and brain MRI were administered at term-equivalent age. Oromotor feeding was assessed at 12 months corrected age using the Schedule for Oral Motor Assessment.

RESULTS

49/227 children had oromotor feeding impairment. Neurobehavior associated with later feeding impairment was: suboptimal NNNS stress (odds ratio [OR] 2.68; 95% confidence interval [CI] 1.20–6.01), non-optimal reflexes (OR 3.33; 95% CI 1.37–8.11) and arousal scales (OR 2.54; 95% CI 1.03–6.27); suboptimal HNNE total (OR 4.69; 95% CI 2.20–10.00), reflexes (OR 2.62; 95% CI 1.06–6.49), and tone scores (OR 3.87; 95% CI 1.45–10.35); and abnormal GMA (OR 2.60; 95% CI 1.21–5.57). Smaller biparietal diameter also predicted feeding impairment (OR 0.88; 95% CI 0.79–0.97). There was little evidence that relationships differed between birth groups.

CONCLUSIONS

Neurobehavior and biparietal diameter at term are associated with oromotor feeding at 12 months. These results may identify children at greatest risk of oromotor feeding impairment.

Neonatal neurological examination during the first 6h after birth

BACKGROUND

Few neurological assessments are easily performed during the first 6h after birth.

AIMS

To assess a cohort of low risk term born newborns within the first 6h and at 48h after birth using the Hammersmith Neonatal Neurological Examination.

STUDY DESIGN AND SUBJECTS

A population of low risk term born newborns was examined within 3h from birth or between 3 and 6h. Each infant was re-assessed at 48h, establishing the range and frequency distribution of neonatal neurological scores at each time point.

RESULTS

Of the 124 full-term born newborns, 62 were assessed at 0-3h and 62 at 3-6h. All infants were re-assessed at 48h. For 23/34 of the neurological items, the range and median scores were similar across the 3 time points. In the remaining 11 items the three groups had a similar range of scores but the median scores were different with different rates of changes. In 6 of the 11 the median scores at 3-6h were similar to those observed at 48h but they appeared to be 'less mature' at 0-3h. Only in one item the median scores were consistently different at the 3 time points.

CONCLUSIONS

Our results suggest that a neurological examination can already be reliably performed soon after birth. These findings will help in the interpretation of the few items that show changes with increasing postnatal age.

The impact of cumulative pain/stress on neurobehavioral development of preterm infants in the NICU

BACKGROUND

Vulnerable preterm infants experience repeated and prolonged pain/stress stimulation during a critical period in their development while in the neonatal intensive care unit (NICU). The contribution of cumulative pain/stressors to altered neurodevelopment remains unclear. The study purpose was to investigate the impact of early life painful/stressful experiences on neurobehavioral outcomes of preterm infants in the NICU.

METHODS

A prospective exploratory study was conducted with fifty preterm infants (28 0/7-32 6/7weeks gestational age) recruited at birth and followed for four weeks. Cumulative pain/stressors (NICU Infant Stressor Scale) were measured daily and neurodevelopmental outcomes (NICU Network Neurobehavioral Scale) were examined at 36-37weeks post-menstrual age. Data analyses were conducted on the distribution of pain/stressors experienced over time and the linkages among pain/stressors and neurobehavioral outcomes.

RESULTS

Preterm infants experienced a high degree of pain/stressors in the NICU, both in numbers of daily acute events (22.97±2.30 procedures) and cumulative times of chronic/stressful exposure (42.59±15.02h). Both acute and chronic pain/stress experienced during early life significantly contributed to the neurobehavioral outcomes, particularly in stress/abstinence (p<0.05) and habituation responses (p<0.01), meanwhile, direct breastfeeding and skin-to-skin holding were also significantly associated with habituation (p<0.01-0.05).

CONCLUSION

Understanding mechanisms by which early life experience alters neurodevelopment will assist clinicians in developing targeted neuroprotective strategies and individualized interventions to improve infant developmental outcomes.

The Dual Nature of Early-Life Experience on Somatosensory Processing in the Human Infant Brain

Every year, 15 million preterm infants are born, and most spend their first weeks in neonatal intensive care units (NICUs) [1]. Although essential for the support and survival of these infants, NICU sensory environments are dramatically different from those in which full-term infants mature and thus likely impact the development of functional brain organization [2]. Yet the integrity of sensory systems determines effective perception and behavior [3, 4]. In neonates, touch is a cornerstone of interpersonal interactions and sensory-cognitive development [5-7]. NICU treatments used to improve neurodevelopmental outcomes rely heavily on touch [8]. However, we understand little of how brain maturation at birth (i.e., prematurity) and quality of early-life experiences (e.g., supportive versus painful touch) interact to shape the development of the somatosensory system [9]. Here, we identified the spatial, temporal, and amplitude characteristics of cortical responses to light touch that differentiate them from sham stimuli in full-term infants. We then utilized this data-driven analytical framework to show that the degree of prematurity at birth determines the extent to which brain responses to light touch (but not sham) are attenuated at the time of discharge from the hospital. Building on these results, we showed that, when controlling for prematurity and analgesics, supportive experiences (e.g., breastfeeding, skin-to-skin care) are associated with stronger brain responses, whereas painful experiences (e.g., skin punctures, tube insertions) are associated with reduced brain responses to the same touch stimuli. Our results shed crucial insights into the mechanisms through which common early perinatal experiences may shape the somatosensory scaffolding of later perceptual, cognitive, and social development.

Neurobehaviour at term-equivalent age and neurodevelopmental outcomes at 2 years in infants born moderate-to-late preterm

AIM

To examine the association between newborn neurobehavioural assessments and neurodevelopmental outcomes at 2 years in infants born moderate-to-late preterm (MLPT).

METHOD

Two-hundred and one infants born MLPT (born 32-36⁺⁶ wks' gestation) were assessed with the Hammersmith Neonatal Neurological Examination (HNNE) and NICU Network Neurobehavioral Scale (NNNS), with suboptimal performance defined as scores lower than the 10th centile. Development was assessed at 2 years corrected age with the Bayley Scales of Infant and Toddler Development 3rd Edition, with delay defined as scores less than 1 standard deviation (SD) below the mean. The relationships between neurobehaviour at term and Bayley-III cognitive, language, and motor scales at 2 years were examined using linear regression.

RESULTS

Increased odds for cognitive delay were associated with suboptimal HNNE total scores (odds ratio [OR] 2.66; 95% confidence interval [CI] 1.14-6.23, p=0.020) and suboptimal NNNS excitability (OR 3.01; 95% CI 1.33-6.82, p=0.008) and lethargy (OR 4.05; 95% CI 1.75-9.31, p=0.001) scores. Suboptimal lethargy scores on the NNNS were associated with increased odds of language (OR 5.64; 95% CI 1.33-23.85, p=0.019) and motor delay (OR: 6.86; 95% CI 1.64-28.71, p=0.08).

INTERPRETATION

Suboptimal performance on specific aspects of newborn neurobehavioural assessments is associated with neurodevelopmental delay at 2 years in children born MLPT.

Implementation of the Hammersmith Infant Neurological Examination in a High-Risk Infant Follow-Up Program

BACKGROUND

High-risk infant follow-up programs provide early identification and referral for treatment of neurodevelopmental delays and impairments. In these programs, a standardized neurological examination is a critical component of evaluation for clinical and research purposes.

METHODS

To address primary challenges of provider educational diversity and standardized documentation, we designed an approach to training and implementation of the Hammersmith Infant Neurological Examination with precourse materials, a workshop model, and adaptation of the electronic medical record.

CONCLUSIONS

Provider completion and documentation of a neurological examination were evaluated before and after Hammersmith Infant Neurological Examination training. Standardized training and implementation of the Hammersmith Infant Neurological Examination in a large high-risk infant follow-up is feasible and effective and allows for quantitative evaluation of neurological findings and developmental trajectories.