Longitudinal outcomes of very low birth weight: neuropsychological findings

Accuracy of Mothers' Perception of Birth Size to Predict Birth Weight Data in Bangladesh

OBJECTIVES

The prevalence of low birth weight (LBW) is an important indicator of child health and wellbeing. However, in many countries, decisions regarding care and treatment are often based on mothers' perceptions of their children's birth size due to a lack of objective birth weight data. Additionally, birth weight data that is self-reported or recorded often encounters the issue of heaping. This study assesses the concordance between the perceived birth size and the reported or recorded birth weight. We also investigate how the presence of heaped birth weight data affects this concordance, as well as the relationship between concordance and various sociodemographic factors.

METHODS

We examined 4,641 birth records reported in the 2019 Bangladesh Multiple Indicator Cluster Survey. The sensitivity-specificity analysis was performed to assess perceived birth size's ability to predict LBW, while Cohen's Kappa statistic assessed reliability. We used the kernel smoothing technique to correct heaping of birth weight data, as well as a multivariable multinomial logistic model to assess factors associated with concordance.

RESULTS

Maternally-perceived birth size exhibited a low sensitivity (63.5%) and positive predictive value (52.6%) for predicting LBW, but a high specificity (90.1%) and negative predictive value (93.4%). There was 86.1% agreement between birth size and birth weight-based classifications (Kappa = 0.49, indicating moderate agreement). Smoothed birth weight data did not improve agreement (83.4%, Kappa = 0.45). Of the sociodemographic factors, early marriage was positively associated with discordance (i.e., overestimation).

CONCLUSIONS

An important consideration when calculating the LBW prevalence is that maternally perceived birth size is not an optimal proxy for birth weight. Focus should be placed on encouraging institutional births and educating community health workers and young mothers about the significance of measuring and recording birth weight.

Self-reported executive function problems in adults born very low birthweight

BACKGROUND

Executive function difficulties are common among children born very preterm and/or very low birthweight (<1500 g; VLBW), but little is known about whether they persist into adulthood.

OBJECTIVES

Examine the nature and pattern of self-reported executive functioning at 23 and 28 years of age using data from a national cohort study of adults born VLBW and a comparison group of same-age full-term (FT) born adults. Also examined were associations between executive function difficulties and socio-economic outcomes.

METHODS

All infants born VLBW in New Zealand during 1986 were prospectively included in an audit of retinopathy of prematurity (n = 413), with 250 (77% of survivors) followed to median age 28 years. A comparison group of FT adults was also recruited at age 23 and followed to 28 years (n = 100). Across both adult assessments, executive functioning was assessed using the Behaviour Rating Inventory of Executive Function-Adult Version (BRIEF-A) and analysed with semi-parametric models to examine the effects of age and group on executive function.

RESULTS

At 23 and 28 years, VLBW adults had increased risk of executive function impairment compared with FT adults in behaviour regulation (relative risk [CI] 2.37, 95% confidence interval (CI)1.27, 4.45), meta-cognition (RR 6.03, 95% CI 2.18, 16.78) and global functioning (RR 3.20, 95% CI 1.40, 7.28). Impaired global executive functioning was associated with lower socio-economic status (regression estimate [b] = -0.43, 95% CI -0.59, -0.27) and a reduced likelihood of home ownership by age 28 years (RR 0.98, 95% CI 0.96, 1.00), even after controlling for sex, ethnicity and parental socio-economic backgrounds for both groups.

CONCLUSION(S)

VLBW-born adults continue to experience more executive function difficulties in their everyday life relative to term controls at age 28 years. These difficulties were negatively associated with their socio-economic opportunities as young adults.

Cognitive, Behavioral and Socioemotional Development in a Cohort of Preterm Infants at School Age: A Cross-Sectional Study

More than 50% of children who survive prematurity have an atypical course of development at school age, as environmental demands become more demanding. This study examines the effects of preterm birth on the cognitive, behavioral and socioemotional development of 185 children at ages five and seven years. Weaknesses were found in attention, working memory, processing speed and the ability to correctly interpret emotions at both ages five and seven. Significant correlations were found in regression and moderation models. These findings suggest that school-age children who were preterm infants are at increased risk of exhibiting impairments in several developmental domains that may affect their overall quality of life.

The impact of premature extrauterine exposure on infants' stimulus-evoked brain activity across multiple sensory systems

Prematurity can result in widespread neurodevelopmental impairment, with the impact of premature extrauterine exposure on brain function detectable in infancy. A range of neurodynamic and haemodynamic functional brain measures have previously been employed to study the neurodevelopmental impact of prematurity, with methodological and analytical heterogeneity across studies obscuring how multiple sensory systems are affected. Here, we outline a standardised template analysis approach to measure evoked response magnitudes for visual, tactile, and noxious stimulation in individual infants (n = 15) using EEG. By applying these templates longitudinally to an independent cohort of very preterm infants (n = 10), we observe that the evoked response template magnitudes are significantly associated with age-related maturation. Finally, in a cross-sectional study we show that the visual and tactile response template magnitudes differ between a cohort of infants who are age-matched at the time of study but who differ according to whether they are born during the very preterm or late preterm period (n = 10 and 8 respectively). These findings demonstrate the significant impact of premature extrauterine exposure on brain function and suggest that prematurity can accelerate maturation of the visual and tactile sensory system in infants born very prematurely. This study highlights the value of using a standardised multi-modal evoked-activity analysis approach to assess premature neurodevelopment, and will likely complement resting-state EEG and behavioural assessments in the study of the functional impact of developmental care interventions.

Cognitive and academic outcomes of children born extremely preterm

Extremely preterm birth is associated with increased risk for a spectrum of neurodevelopmental problems. This review describes the nature of cognitive and academic outcomes of extremely preterm survivors across childhood and adolescence. Evidence across meta-analyses and large prospective birth cohorts indicate that early developmental difficulties in children born extremely preterm do not resolve with age and are not improving over time despite advancements in neonatal care. While extremely preterm birth confers increased risk of widespread cognitive difficulties, considerable heterogeneity in outcomes is evident across individuals. There is a continued need for high-quality longitudinal studies to understand the developmental progression of cognitive and academic skills following extremely preterm birth, and greater focus on understanding contributing factors that may help to explain the individual variability in cognitive and academic outcomes of extremely preterm survivors.

Gestational Age is Dimensionally Associated with Structural Brain Network Abnormalities Across Development

Prematurity is associated with diverse developmental abnormalities, yet few studies relate cognitive and neurostructural deficits to a dimensional measure of prematurity. Leveraging a large sample of children, adolescents, and young adults (age 8-22 years) studied as part of the Philadelphia Neurodevelopmental Cohort, we examined how variation in gestational age impacted cognition and brain structure later in development. Participants included 72 preterm youth born before 37 weeks' gestation and 206 youth who were born at term (37 weeks or later). Using a previously-validated factor analysis, cognitive performance was assessed in three domains: (1) executive function and complex reasoning, (2) social cognition, and (3) episodic memory. All participants completed T1-weighted neuroimaging at 3 T to measure brain volume. Structural covariance networks were delineated using non-negative matrix factorization, an advanced multivariate analysis technique. Lower gestational age was associated with both deficits in executive function and reduced volume within 11 of 26 structural covariance networks, which included orbitofrontal, temporal, and parietal cortices as well as subcortical regions including the hippocampus. Notably, the relationship between lower gestational age and executive dysfunction was accounted for in part by structural network deficits. Together, these findings emphasize the durable impact of prematurity on cognition and brain structure, which persists across development.

Executive function deficits mediate the association between very preterm birth and behavioral problems at school-age

BACKGROUND & AIMS

Children and adolescents born very preterm are at increased risk to develop executive function deficits and to suffer from social, emotional and attentional problems. This study investigated whether executive function deficits contribute to behavioral problems in children and adolescents born very preterm at school-age.

STUDY DESIGN

Thirty-eight children and adolescents born very preterm and 41 age-matched term-born peers were assessed at a mean age of 12.9 (±1.8) years with a comprehensive battery of executive function tests, including working memory, planning, cognitive flexibility, and verbal fluency. A composite score was calculated to reflect overall executive function abilities. To assess behavioral problems, parents completed the Strengths and Difficulties Questionnaire (SDQ). Mediation analysis was applied to quantify the effect of preterm birth on behavioral problems with executive function abilities as a mediating variable.

RESULTS

Executive function abilities were poorer in the very preterm compared to the term-born group (d = 0.62, p = .005) and the parents of very preterm children reported more behavioral problems on the SDQ Total Difficulties Score (d = 0.54, p = .01). The effect of birth status on behavioral problems was significantly mediated by executive function abilities while adjusting for age at assessment, sex, and socioeconomic status (F(2, 76) = 6.42, p = .002, R² = 0.14).

CONCLUSION

Results from this study suggest that the increase in behavioral symptoms in very preterm children at school-age compared to term-born peers may partly be explained by their executive function deficits. These findings highlight the importance of continuously monitoring the development of children born very preterm to provide optimal care as they grow up.

Effect of Prenatal Smoke Exposure on Birth Weight: The Moderating Role of Maternal Depressive Symptoms

INTRODUCTION

Both prenatal smoke exposure and depression have been linked to lower birth weight, a risk factor for morbidity and mortality. Few studies have looked at the interaction between these risk factors and none have used a biomarker to objectively measure prenatal smoke exposure. The current study sought to examine independent and interactive effects of cotinine and depression on birth weight. The effect of race was also explored.

METHOD

Data were drawn from a prospective study of pregnant women (N = 568) in the southeastern United States. Maternal demographic, health information, depressive symptoms, and birth data were collected via self-report and medical record abstraction. Prenatal blood samples were assayed for cotinine.

RESULTS

Controlling for covariates, multiple regression analyses indicated that both cotinine and depressive symptoms independently predicted lower birth weight and a significant interaction was also observed. Upon probing the interaction, a negative association between cotinine levels and birth weight was found in the context of higher depression but not lower depression scores. Similarly, logistic regression analyses revealed a significant interaction between cotinine and depression, such that cotinine predicted having a baby less than 2500 g among women who fell above the indicated cutoff score. African American women had the highest levels of cotinine and lowest weight babies; however, race was not a significant moderator.

CONCLUSIONS

Results suggest prenatal smoke exposure has a greater negative effect on birth weight for women endorsing co-occurring depressive symptoms. Findings can inform targeted interventions and assist medical providers with identifying women at increased risk for poor perinatal outcomes.

IMPLICATIONS

Despite the common occurrence of smoking during pregnancy and prenatal depression, the interaction between these risk factors on birth weight has rarely been examined. Further, the extant results have been mixed, likely due in part to difficulties in measurement. The current study was the first to use prenatal cotinine to assess bias-free, continuous levels of prenatal smoke exposure. Results indicate that prenatal cotinine was a significant predictor of birth weight only in the context of maternal depressive symptoms. These findings have important implications for mitigating negative perinatal outcomes for pregnant women and their children.

Spectral slowing is associated with working memory performance in children born very preterm

Children born very preterm (VPT) often demonstrate selective difficulties in working memory (WM), which may underlie academic difficulties observed in this population. Despite this, few studies have investigated the functional networks underlying WM in young children born VPT, a period when cognitive deficits become apparent. Using magnetoencephalography, we examined the networks underlying the maintenance of visual information in 6-year-old VPT (n = 15) and full-term (FT; n = 20) children. Although task performance was similar, VPT children engaged different oscillatory mechanisms during WM maintenance. Within the FT group, we observed higher mean whole-brain connectivity in the alpha-band during the retention (i.e. maintenance) interval associated with correct compared to incorrect responses. VPT children showed reduced whole-brain alpha synchrony, and a different network organization with fewer connections. In the theta-band, VPT children demonstrated a slight increase in whole-brain connectivity during WM maintenance, and engaged similar network hubs as FT children in the alpha-band, including the left dorsolateral prefrontal cortex and superior temporal gyrus. These findings suggest that VPT children rely on the theta-band to support similar task performance. Altered oscillatory mechanisms may reflect a less mature pattern of functional recruitment underlying WM in VPT children, which may affect the processing in complex ecological situations.

The Influence of Early Nutrition on Brain Growth and Neurodevelopment in Extremely Preterm Babies: A Narrative Review

Extremely preterm babies are at increased risk of less than optimal neurodevelopment compared with their term-born counterparts. Optimising nutrition is a promising avenue to mitigate the adverse neurodevelopmental consequences of preterm birth. In this narrative review, we summarize current knowledge on how nutrition, and in particular, protein intake, affects neurodevelopment in extremely preterm babies. Observational studies consistently report that higher intravenous and enteral protein intakes are associated with improved growth and possibly neurodevelopment, but differences in methodologies and combinations of intravenous and enteral nutrition strategies make it difficult to determine the effects of each intervention. Unfortunately, there are few randomized controlled trials of nutrition in this population conducted to determine neurodevelopmental outcomes. Substantial variation in reporting of trials, both of nutritional intakes and of outcomes, limits conclusions from meta-analyses. Future studies to determine the effects of nutritional intakes in extremely preterm babies need to be adequately powered to assess neurodevelopmental outcomes separately in boys and girls, and designed to address the many potential confounders which may have clouded research findings to date. The development of minimal reporting sets and core outcome sets for nutrition research will aid future meta-analyses.

Resilience in Extremely Preterm/Extremely Low Birth Weight Kindergarten Children

OBJECTIVES

Research on developmental outcomes of preterm birth has traditionally focused on adverse effects. This study investigated the prevalence and correlates of resilience in 146 extremely preterm/extremely low birth weight (EPT/ELBW) children (gestational age &lt;28 weeks and/or birth weight &lt;1000 g) attending kindergarten and 111 term-born normal birth weight (NBW) controls.

METHODS

Adaptive competence (i.e., "resilience" in the EPT/ELBW group) was defined by scores within grade expectations on achievement tests and the absence of clinically elevated parent ratings of child behavior problems. The "adaptive" children who met these criteria were compared to the "maladaptive" children who did not on child and family characteristics. Additional analyses were conducted to assess the conjoint effects of group (ELBW vs. NBW) and family factors on adaptive competence.

RESULTS

A substantial minority of the EPT/ELBW group (45%) were competent compared to a majority of NBW controls (73%), odds ratio (95% confidence interval)=0.26 (0.15, 0.45), p&lt;.001. Adaptive competence was associated with higher cognitive skills, more favorable ratings of behavior and learning not used to define adaptive competence, and more advantaged family environments in both groups, as well as with a lower rate of earlier neurodevelopmental impairment in the EPT/ELBW group. Higher socioeconomic status and more favorable proximal home environments were associated with competence independent of group, and group differences in competence persisted across the next two school years.

CONCLUSIONS

The findings document resilience in kindergarten children with extreme prematurity and highlight the role of environmental factors as potential influences on outcome. (JINS, 2019, 25, 362-374).

A Comparison of Developmental Outcomes of Adolescent Neonatal Intensive Care Unit Survivors Born with a Congenital Heart Defect or Born Preterm

OBJECTIVE

To compare cognitive, motor, behavioral, and functional outcomes of adolescents born with a congenital heart defect (CHD) and adolescents born preterm.

STUDY DESIGN

Adolescents (11-19 years old) born with a CHD requiring open-heart surgery during infancy (n = 80) or born preterm ≤29 weeks of gestational age (n = 128) between 1991 and 1999 underwent a cross-sectional evaluation of cognitive (Leiter International Performance Scale-Revised), motor (Movement Assessment Battery for Children-II), behavioral (Strengths and Difficulties Questionnaire), and functional (Vineland Adaptive Behavior Scale-II) outcomes. Independent samples t tests and Pearson χ² or Fisher exact tests were used to compare mean scores and proportions of impairment, respectively, between groups.

RESULTS

Adolescents born with a CHD and adolescents born preterm had similar cognitive, motor, behavioral, and functional outcomes. Cognitive deficits were detected in 14.3% of adolescents born with a CHD and 11.8% of adolescents born preterm. Motor difficulties were detected in 43.5% of adolescents born with a CHD and 50% of adolescents born preterm. Behavioral problems were found in 23.7% of adolescents in the CHD group and 22.9% in the preterm group. Functional limitations were detected in 12% of adolescents born with a CHD and 7.3% of adolescents born preterm.

CONCLUSIONS

Adolescents born with a CHD or born preterm have similar profiles of developmental deficits. These findings highlight the importance of providing long-term surveillance to both populations and guide the provision of appropriate educational and rehabilitation services to better ameliorate long-term developmental difficulties.

Preterm brain Injury: White matter injury

Despite the advances in neonatal intensive care, the preterm brain remains vulnerable to white matter injury (WMI) and disruption of normal brain development (i.e., dysmaturation). Compared to severe cystic WMI encountered in the past decades, contemporary cohorts of preterm neonates experience milder WMIs. More than destructive lesions, disruption of the normal developmental trajectory of cellular elements of the white and the gray matter occurs. In the acute phase, in response to hypoxia-ischemia and/or infection and inflammation, multifocal areas of necrosis within the periventricular white matter involve all cellular elements. Later, chronic WMI is characterized by diffuse WMI with aberrant regeneration of oligodendrocytes, which fail to mature to myelinating oligodendrocytes, leading to myelination disturbances. Complete neuronal degeneration classically accompanies necrotic white matter lesions, while altered neurogenesis, represented by a reduction of the dendritic arbor and synapse formation, is observed in response to diffuse WMI. Neuroimaging studies now provide more insight in assessing both injury and dysmaturation of both gray and white matter. Preterm brain injury remains an important cause of neurodevelopmental disabilities, which are still observed in up to 50% of the preterm survivors and take the form of a complex combination of motor, cognitive, and behavioral concerns.

The influence of prenatal experience on behavioral and social development: The benefits and limitations of an animal model

Prenatal experience is both a formative and a regulatory force in the process of development. As a result, birth is not an adequate starting point for explanations of behavioral development. However, surprisingly little is currently known regarding the role of prenatal experience in the emergence and facilitation of perceptual, cognitive, or social development. Our lack of knowledge in this area is due in part to the very restricted experimental manipulations possible with human fetuses. A comparative approach utilizing animal models provides an essential step in addressing this gap in our knowledge and providing testable predictions for studies with human fetuses, infants, and children. Further, animal-based comparative research serves to minimize the amount of exploratory research undertaken with human subjects and hone in on issues and research directions worthy of further research investment. In this article, I review selected animal-based research exploring how developmental influences during the prenatal period can guide and constrain subsequent behavioral and social development. I then discuss the importance of linking the prenatal environment to postnatal outcomes in terms of how psychologists conceptualize “innate” biases, preferences, and skills in the study of human development.

Anemia of prematurity and cerebral near-infrared spectroscopy: should transfusion thresholds in preterm infants be revised?

OBJECTIVE

To determine the impact of progressive anemia of prematurity on cerebral regional saturation (C-rSO₂) in preterm infants and identify the hemoglobin threshold below which a critical decrease (>2SD below the mean) in C-rSO₂ occurs.

STUDY DESIGN

In a cohort of infants born ≤30 weeks EGA, weekly C-rSO₂ data were prospectively collected from the second week of life through 36 weeks post-menstrual age (PMA). Clinically obtained hemoglobin values were noted at the time of recording. Recordings were excluded if they were of insufficient duration (<1 h) or if the hemoglobin was not measured within 7 days. Statistical analysis was performed using a linear mixed effects-model and ROC analysis. ROC analysis was used to determine the threshold of anemia, where C-rSO₂ critically decreased >2SD below the mean normative value (<55%) in preterm infants.

RESULTS

In total 253 recordings from 68 infants (mean EGA 26.9 ± 2.1 weeks, BW 1025 ± 287 g, 49% male) were included. Approximately 29 out of 68 infants (43%) were transfused during hospitalization. Mixed-model statistical analysis adjusting for EGA, BW, and PMA revealed a significant association between decreasing hemoglobin and C-rSO₂ (p < 0.01) in transfusion-naive infants but not in transfused infants. In the transfusion naive group, using ROC analysis demonstrated a threshold hemoglobin of 9.5 g/dL (AUC 0.81, p < 0.01) for critical cerebral desaturation in preterm infants.

CONCLUSIONS

In transfusion-naive preterm infants, worsening anemia was associated with a progressive decrease in cerebral saturations. Analysis identified a threshold hemoglobin of 9.5 g/dL below which C-rSO₂ dropped >2SD below the mean.

Leisure time physical activity in 9- to 11-year-old children born moderately preterm: a cohort study

BACKGROUND

Physical activity is one of the best documented activities with impacts on health in children and adults. Children born preterm show reduced physical and psychosocial function compared to children born at term. This may influence their level of physical activity. Reports on moderately preterm children's physical activities during childhood are limited. Thus, the aim of this study was to compare the leisure time physical activity at age 9-11 years of moderately preterm children with that of children born at term.

METHODS

Data from 4941 mother-child pairs from the Aarhus Birth Cohort (1989-91) were used. The cohort gathered clinical information, including gestational age at delivery. Information about parental socio-demographic and lifestyle factors was obtained from questionnaires completed during the second trimester of pregnancy. Information about children's physical activities was reported in a 9- to 11-year follow-up questionnaire completed by parents detailing how many times per week their child participated in sports activities outside of school, hours spent per week playing outside, and hours per week engaged in sedentary activities. Data were analysed using multiple logistic regression with the lowest activity group as a reference group.

RESULTS

A total of 158 children (3.2%) were born moderately preterm, i.e., between 32 and 36 completed weeks. Children born moderately preterm participated in sports activities as often as their peers born at term; they also participated in frequent sports activities (≥ 4 times per week) as often as their peers. There were no differences in hours per week spent playing outside or in sedentary activities between the two groups.

CONCLUSIONS

Nine- to 11-year-old moderately preterm children participated in sports activities outside school to a similar extent as their peers and engaged in outdoor activities and sedentary activities for the same duration of time per week as their peers born at term.

Cognitive trajectories from infancy to early adulthood following birth before 26 weeks of gestation: a prospective, population-based cohort study

OBJECTIVE

To determine the trajectory of cognitive test scores from infancy to adulthood in individuals born extremely preterm compared with term-born individuals.

DESIGN

A prospective, population-based cohort study.

SETTING

276 maternity units in the UK and Ireland.

PATIENTS

315 surviving infants born less than 26 completed weeks of gestation recruited at birth in 1995 and 160 term-born classroom controls recruited at age 6.

MAIN OUTCOME MEASURES

Bayley Scales of Infant Development-Second Edition (age 2.5); Kaufman Assessment Battery for Children (ages 6/11); Wechsler Abbreviated Scale of Intelligence-Second Edition (age 19).

RESULTS

The mean cognitive scores of extremely preterm individuals over the period were on average 25.2 points below their term-born peers (95% CI -27.8 to -22.6) and remained significantly lower at every assessment. Cognitive trajectories in term-born boys and girls did not differ significantly, but the scores of extremely preterm boys were on average 8.8 points below those of extremely preterm girls (95% CI -13.6 to -4.0). Higher maternal education elevated scores in both groups by 3.2 points (95% CI 0.8 to 5.7). Within the extremely preterm group, moderate/severe neonatal brain injury (mean difference: -10.9, 95% CI -15.5 to -6.3) and gestational age less than 25 weeks (mean difference: -4.4, 95% CI -8.4 to -0.4) also had an adverse impact on cognitive function.

CONCLUSIONS

There is no evidence that impaired cognitive function in extremely preterm individuals materially recovers or deteriorates from infancy through to 19 years. Cognitive test scores in infancy and early childhood reflect early adult outcomes.

Antenatal and Neonatal Antecedents of Executive Dysfunctions in Extremely Preterm Children

To find out why children born extremely preterm are at heightened risk of executive dysfunctions, the authors assessed 716 children who were 10 years old born extremely preterm whose IQ was ≥ 70. A working memory dysfunction (n = 169), an inhibition dysfunction (n = 360), a switching dysfunction (355), and all 3 (executive dysfunction; n = 107) were defined on the basis of Z-scores ≤ -1 on the Differential Ability Scales-II Working Memory composite, and/or on the NEPSY-II Inhibition-Inhibition and Inhibition-Switching subtests. All risk profiles include an indicator of socioeconomic disadvantage. The risk profile of each of the 3 individual dysfunctions includes an indicator of the newborn's immaturity, and the risk profiles of the inhibition dysfunction and switching dysfunction also include an indicator of inflammation. Only the switching dysfunction was associated with fetal growth restriction. The risk factors for executive dysfunction can be subsumed under the 4 themes of socioeconomic disadvantage, immaturity/vulnerability, inflammation, and fetal growth restriction.

[Disturbance of oligodendrocyte differentiation in schizophrenia in relation to main hypothesis of the disease]

Increasing evidence coming from neuroimaging, molecular genetic and post-mortem studies have implicated oligodendrocyte abnormalities and compromised myelin integrity in schizophrenia. Activity-dependent myelination in adult brain is considered to be an important mechanism of neural circuit's plasticity due to the presence of a large population of oligodendrocyte progenitor cells (OPC) in the adult CNS. Growing evidence for impairment of oligodendrocyte differentiation has been reported in the brain of schizophrenia subjects. OPC are very vulnerable inflammation, oxidative stress, and elevated glutamate levels leading to excitotoxicity. The mechanisms of prolonged suppression of oligodendrocyte differentiation caused by prenatal maternal infection or preterm birth are discussed in view of increased risk of schizophrenia, neurodevelopmental and inflammation hypotheses of the disease. The data that some neuroleptics stimulate OPC differentiation and ameliorate myelin alterations support the notion that impairment in the differentiation of OPCs contributes to oligodendrocyte abnormalities and to the pathophysiology of schizophrenia.

Developmental progression and side specialization in upper-limb movements from 4 to 8 years in children born preterm and fullterm

This study investigated developmental changes and differences in upper-limb movement organization from 4 to 8 years of age in children born preterm (PT) and fullterm (FT). Kinematic recordings of precision-demanding unimanual movements and lateral assessments were carried out in 37 children (18 PT). All children, particularly children born PT, displayed considerable gain in movement kinematics. Contrary to controls, children born PT displayed persistently less-evident side preference. Gestational age (GA) contributed significantly to kinematic differences shown, with larger upper-limb deviances in the lowest GAs, in agreement with cross-sectional findings of altered hemispheric connections and delayed side-specialization among children born very PT.

Fine Motor Skill Mediates Visual Memory Ability with Microstructural Neuro-correlates in Cerebellar Peduncles in Prematurely Born Adolescents

Adolescents born preterm (PT) with no evidence of neonatal brain injury are at risk of deficits in visual memory and fine motor skills that diminish academic performance. The association between these deficits and white matter microstructure is relatively unexplored. We studied 190 PTs with no brain injury and 92 term controls at age 16 years. The Rey-Osterrieth Complex Figure Test (ROCF), the Beery visual-motor integration (VMI), and the Grooved Pegboard Test (GPT) were collected for all participants, while a subset (40 PTs and 40 terms) underwent diffusion-weighted magnetic resonance imaging. PTs performed more poorly than terms on ROCF, VMI, and GPT (all P < 0.01). Mediation analysis showed fine motor skill (GPT score) significantly mediates group difference in ROCF and VMI (all P < 0.001). PTs showed a negative correlation (P < 0.05, corrected) between fractional anisotropy (FA) in the bilateral middle cerebellar peduncles and GPT score, with higher FA correlating to lower (faster task completion) GPT scores, and between FA in the right superior cerebellar peduncle and ROCF scores. PTs also had a positive correlation (P < 0.05, corrected) between VMI and left middle cerebellar peduncle FA. Novel strategies to target fine motor skills and the cerebellum may help PTs reach their full academic potential.

Effect of intimate partner violence on birth outcomes

Background

Violence by intimate partner during pregnancy has many adverse pregnancy outcomes. Thus, that's why we sought to determine association between intimate partner violence during pregnancy and adverse birth outcomes.

Methods

A facility based cross-sectional study was conducted among 183 recently delivered women from March 31–April 30, 2014 in public health facilities of Hossana Town. The data were collected through structured questionnaire and record review. Women who were not mentally and physically capable of being interviewed and those admitted for abortion were excluded. Ethical clearance was obtained from Jimma University. Logistic regression analysis was employed to determine the association between intimate partner violence and adverse birth outcomes.

Results

About 23 % of women experienced intimate partner violence during pregnancy. The result of this study indicated an association of intimate partner violence with low birth weight of the new born (AOR:14.3,95% CI: (5.03, 40.7). Intimate partner violence was not associated with still birth, pre-term birth and Apgar score less than 7 at 5 minutes.

Conclusion

The findings of this study showed that intimate partner violence during pregnancy was associated with a low birth weight of the new born. Health sectors should train health care providers on how to screen, counsel, treat and follow up abused women.

Executive Function and Academic Outcomes in Children Who Were Extremely Preterm

OBJECTIVES

Cognitive and behavioral impairments of children born extremely preterm (EP) (<28 weeks' gestation) and extremely low birth weight (ELBW) (<1000 g) may change with age. We assessed the individual stability of behavioral executive function (EF) from 8 to 18 years of age in children born EP or ELBW and their academic outcomes.

METHODS

Participants comprised 180 children born EP or ELBW from a large geographic cohort. We investigated the frequency of 4 developmental groups (persistent, remitting, late-onset, and typical development) on the basis of dichotomized scores (typical versus elevated) at ages 8 and 18 years in 2 indices (the Behavioral Regulation Index [BRI] and the Metacognition Index [MCI]) of the parental form of the Behavior Rating Inventory of Executive Function. Adolescent academic outcomes were measured by using the word reading, spelling, and math computation subtests of the Wide Range Achievement Test, Fourth Edition.

RESULTS

Most participants had a typical EF (BRI 61%, MCI 53%), followed by persistent (BRI 15%, MCI 16%), late-onset (BRI 12%, MCI 19%), or remitting (BRI 12%, MCI 13%) executive difficulties. Groups with executive impairments at age 18 years (persistent and late onset) had poorer academic outcomes than the typical and remitting groups. Shifting impairment categories between 8 and 18 years old was relevant to later academic outcomes.

CONCLUSIONS

Most children showed stable and age-appropriate EF, although persistent and transient difficulties were observed and related to uneven academic outcomes. Studying the origins and consequences of the developmental stability of EF may contribute to the development of interventions to decrease the adverse neurodevelopmental outcomes of preterm birth.

Executive function in children born preterm: Risk factors and implications for outcome

Executive function (EF) refers to the set of cognitive processes involved in the self-regulation of emotion and goal-directed behavior. These skills and the brain systems that support them develop throughout childhood and are frequently compromised in preterm children, even in those with broadly average global cognitive ability. Risks for deficits in EF in preterm children and attendant problems in learning and psychosocial functioning are higher in those with more extreme prematurity, neonatal complications, and related brain abnormalities. Associations of higher levels of EF with more supportive home and school environments suggest a potential for attenuating these risks, especially with early identification. Further research is needed to understand how deficits in EF evolve in preterm children, refine assessment methods, and develop interventions that either promote the development of EF in this population or help children to compensate for these weaknesses.

Functional Connectivity of the Infant Human Brain: Plastic and Modifiable

Infancy is a critical and immensely important period in human brain development. Subtle changes during this stage may be greatly amplified with the unfolding of different developmental processes, exerting far-reaching consequences. Studies of the structure and behavioral manifestations of the infant brain are fruitful. However, the specific functional brain mechanisms that enable the execution of different behaviors remained elusive until the advent of functional connectivity fMRI (fcMRI), which provides an unprecedented opportunity to probe the infant functional brain development in vivo. Since its inception, a burgeoning field of infant brain functional connectivity study has emerged and thrived during the past decade. In this review, we describe (1) findings of normal development of functional connectivity networks and their relationships to behaviors and (2) disruptions of the normative functional connectivity development due to identifiable genetic and/or environmental risk factors during the first 2 years of human life. Technical considerations of infant fcMRI are also provided. It is our hope to consolidate previous findings so that the field can move forward with a clearer picture toward the ultimate goal of fcMRI-based objective methods for early diagnosis/identification of risks and evaluation of early interventions to optimize developing functional connectivity networks in this critical developmental window.

Early intervention leads to long-term developmental improvements in very preterm infants, especially infants with bronchopulmonary dysplasia

AIM

Various early intervention programmes have been developed in response to the high rate of neurodevelopmental problems in very preterm infants. We investigated longitudinal effects of the Infant Behavioral Assessment and Intervention Program on cognitive and motor development of very preterm infants at the corrected ages of six months to five and a half years.

METHODS

This randomised controlled trial divided 176 infants with a gestational age <32 weeks or birthweight <1500 g into intervention (n = 86) and control (n = 90) groups. Cognitive development and motor development were assessed with the Bayley Scales of Infant Development at the CAs of six, 12 and 24 months and at five and a half years with the Wechsler Preschool and Primary Scale of Intelligence and the Movement Assessment Battery for Children.

RESULTS

We found significant longitudinal intervention effects (0.4 SD, p = 0.006) on motor development, but no significant impact on cognitive development (p = 0.063). Infants with bronchopulmonary dysplasia showed significant longitudinal intervention effects for cognitive (0.7 SD; p = 0.019) and motor (0.9 SD; p = 0.026) outcomes. Maternal education had little effect on intervention effects over time.

CONCLUSION

The Infant Behavioral Assessment and Intervention Program led to long-term developmental improvements in the intervention group, especially in infants with BPD.

The Impact of Special Health Care Needs on Academic Achievement in Children Born Prematurely

BACKGROUND

Preterm, low-birth-weight (LBW) children are at increased risk for poor academic achievement and special health care needs (SHCN) compared to term-born peers. It is not known how having SHCN during childhood modifies the relationship between LBW and achievement over time.

METHODS

We used data from the Infant Health and Development Program, a multisite randomized trial of an intervention for preterm, LBW infants with longitudinal follow-up. Primary outcome measures were Woodcock-Johnson Tests of Academic Achievement math and reading scores at age 8 and 18 years. Primary predictor was having a SHCN, defined by prescription medication and medical services use, receipt of special therapies, or any functional limitation. We used repeated measures multivariate analysis of covariance to test the effect of SHCN on achievement at 8 and 18 years and effect modification by IQ.

RESULTS

The 576 participants had a mean body weight of 1798.1 ± 455.0 g and a median gestational age of 33 weeks (range, 26-37 weeks). Mean achievement scores were as follows: math (age 8) 97.5 ± 21.6, math (age 18) 90.1 ± 18.3, reading (age 8) 99.0 ± 20.1, and reading (age 18) 96.8 ± 23.5. Mean full scale IQ at age 8 was 92.3 ± 18.2. Eighty percent had a SHCN. Mean achievement scores were significantly different between those with and without SHCN in both math and reading. There was no evidence of effect modification by IQ.

CONCLUSIONS

SHCNs are associated with poor academic achievement. Targeted interventions for improving performance outcomes by reducing the burden of chronic health problems may be accomplished through prevention strategies or efforts to limit the frequency and severity of symptoms.

Desempenho linguístico de prematuros de 2 anos, considerando idade cronológica e idade corrigida

RESUMO Introdução O nascimento prematuro acarreta problemas que não se restringem à mortalidade perinatal. Alguns prematuros, mesmo na ausência de lesões cerebrais, apresentam consequências negativas em diversos aspectos do desenvolvimento, como dificuldades em adquirir linguagem. Objetivo O objetivo deste estudo foi verificar o desempenho linguístico de prematuros, na faixa etária de 2 anos, considerando a idade cronológica e a idade corrigida. Métodos Participaram do estudo 23 sujeitos prematuros e para verificar as habilidades linguísticas foi aplicado o Test of Early Language Development – TELD-3. Resultados Os sujeitos prematuros apresentaram desempenho total alterado no TELD-3 em 39,13% dos casos. Os prematuros também foram analisados considerando o atraso para a idade cronológica e a corrigida e não houve diferença no desempenho para os subtestes receptivo (p = 0,250) e expressivo (p = 1,000). Conclusão O grupo de prematuros aos 2 anos de idade constitui população de risco para alterações de linguagem que não podem ser compensadas com a correção da idade.

Evidence of a Gene × Environment Interaction Between Birth Weight and Genetic Risk in the Prediction of Criminogenic Outcomes Among Adolescent Males

A number of studies have revealed that low birth weight children have a heightened risk of various maladaptive outcomes, including academic challenges and delinquent involvement. However, very little research to date has examined whether the relationship between low birth weight, poor academic performance, and delinquent peer affiliation is moderated by genetic risk. Using data from the National Longitudinal study of Adolescent Health, the present study examines whether male adolescents born at very low birth weights are significantly predisposed to poor academic performance and delinquent peer affiliation. Moreover, we test whether the effect of birth weight on these outcomes is conditioned by level of genetic risk. We find no evidence that very low birth weight males are more likely to affiliate with delinquent peers or perform poorly in school during adolescence. However, upon examining gene-environment interactions, we find that being born at a very low birth weight does significantly increase the odds of poor academic performance and delinquent peer affiliation among males who possess a higher level of genetic risk. Limitations are noted and the implications of the findings are discussed.

Maternal associated factors of low birth weight: a hospital based cross-sectional mixed study in Tigray, Northern Ethiopia

BACKGROUND

Birth weight is an important determinant of child survival and development. So far, the prevalence and traditional maternal feeding practice correlates of low birth weight have not been explored well in Ethiopia. Therefore, the purpose of this study was to determine the prevalence and associated factors of low birth weight among mothers who delivered at governmental hospitals, Northern, Ethiopia.

METHODS

A cross-sectional mixed study design was carried out in 3 zonal hospitals among 308 mothers and their respective live born baby consecutively using interviewer administered piloted questionnaire and 3 focus group discussions were conducted for the qualitative part. The mothers were interviewed and assessed within 6 hours of delivery; all babies were weighed on standard beam balance from Aug 2 to Sep 12. Data were entered, cleaned and analyzed using SPSS version 16.0. Bivariate and multivariate logistic regression was employed to identify the predictors at p < 0.05. For the qualitative study design, following iterative hearing of the discussions verbatim interpretation was done & categorized in to themes and finally triangulated with the quantitative results.

RESULTS

The prevalence of low birth weight was found to be 14.6% (95 % CI = 12.56-16.61) and the mean and standard deviations of the birth weights were 3094.9 ± 587.6 grams. Low birth weight was associated with rural place of residence (AOR = 4.34 (95 % CI = 1.99-9.48)), preterm birth/gestational age less than 37 weeks (AOR = 18.5 (95 % CI = 4.94-69.4)), presence of any chronic medical illness (AOR = 5.3 (95 % CI = 1.12-25.45) and maternal weight <50 kg (AOR = 2.26 (95 % CI = 1.06-4.80)). It was found that tradition of selection and preference of nutritionally poor food items during pregnancy was deep-rooted in the community.

CONCLUSION

The prevalence of low birth weight was found to be high and it was associated with rural place of residence, gestational age <37 wks, presence of any chronic medical illness & maternal weight <50 kg. Emphasis should be given to nutritional counseling and disease specific ANC provision by skilled health professionals; Discussions with the community and religious leaders are mandatory aspect on the tradition of feeding of pregnant mothers to tackle the problem. This study also calls for community based further studies.

Brain Injury in the Preterm Infant: New Horizons for Pathogenesis and Prevention

Preterm neonates are surviving with a milder spectrum of motor and cognitive disabilities that appear to be related to widespread disturbances in cell maturation that target cerebral gray and white matter. Whereas the preterm brain was previously at high risk for destructive lesions, preterm survivors now commonly display less severe injury that is associated with aberrant regeneration and repair responses that result in reduced cerebral growth. Impaired cerebral white matter growth is related to myelination disturbances that are initiated by acute death of premyelinating oligodendrocytes, but are followed by rapid regeneration of premyelinating oligodendrocytes that fail to normally mature to myelinating cells. Although immature neurons are more resistant to cell death than mature neurons, they display widespread disturbances in maturation of their dendritic arbors and synapses, which further contributes to impaired cerebral growth. Thus, even more mild cerebral injury involves disrupted repair mechanisms in which neurons and premyelinating oligodendrocytes fail to fully mature during a critical window in development of neural circuitry. These recently recognized distinct forms of cerebral gray and white matter dysmaturation raise new diagnostic challenges and suggest new therapeutic strategies to promote brain growth and repair.

Automatic segmentation of the hippocampus for preterm neonates from early-in-life to term-equivalent age

Introduction

The hippocampus, a medial temporal lobe structure central to learning and memory, is particularly vulnerable in preterm-born neonates. To date, segmentation of the hippocampus for preterm-born neonates has not yet been performed early-in-life (shortly after birth when clinically stable). The present study focuses on the development and validation of an automatic segmentation protocol that is based on the MAGeT-Brain (Multiple Automatically Generated Templates) algorithm to delineate the hippocampi of preterm neonates on their brain MRIs acquired at not only term-equivalent age but also early-in-life.

Methods

First, we present a three-step manual segmentation protocol to delineate the hippocampus for preterm neonates and apply this protocol on 22 early-in-life and 22 term images. These manual segmentations are considered the gold standard in assessing the automatic segmentations. MAGeT-Brain, automatic hippocampal segmentation pipeline, requires only a small number of input atlases and reduces the registration and resampling errors by employing an intermediate template library. We assess the segmentation accuracy of MAGeT-Brain in three validation studies, evaluate the hippocampal growth from early-in-life to term-equivalent age, and study the effect of preterm birth on the hippocampal volume. The first experiment thoroughly validates MAGeT-Brain segmentation in three sets of 10-fold Monte Carlo cross-validation (MCCV) analyses with 187 different groups of input atlases and templates. The second experiment segments the neonatal hippocampi on 168 early-in-life and 154 term images and evaluates the hippocampal growth rate of 125 infants from early-in-life to term-equivalent age. The third experiment analyzes the effect of gestational age (GA) at birth on the average hippocampal volume at early-in-life and term-equivalent age using linear regression.

Results

The final segmentations demonstrate that MAGeT-Brain consistently provides accurate segmentations in comparison to manually derived gold standards (mean Dice's Kappa > 0.79 and Euclidean distance <1.3 mm between centroids). Using this method, we demonstrate that the average volume of the hippocampus is significantly different (p < 0.0001) in early-in-life (621.8 mm³) and term-equivalent age (958.8 mm³). Using these differences, we generalize the hippocampal growth rate to 38.3 ± 11.7 mm³/week and 40.5 ± 12.9 mm³/week for the left and right hippocampi respectively. Not surprisingly, younger gestational age at birth is associated with smaller volumes of the hippocampi (p = 0.001).

Conclusions

MAGeT-Brain is capable of segmenting hippocampi accurately in preterm neonates, even at early-in-life. Hippocampal asymmetry with a larger right side is demonstrated on early-in-life images, suggesting that this phenomenon has its onset in the 3rd trimester of gestation. Hippocampal volume assessed at the time of early-in-life and term-equivalent age is linearly associated with GA at birth, whereby smaller volumes are associated with earlier birth.

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We develop a MAGeT-Brain based automatic protocol to segment hippocampus in preterm neonates.

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MAGeT-Brain can accurately segment hippocampus in preterm neonates, even at early-in-life.

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Hippocampal asymmetry with a larger right side is demonstrated on early-in-life images.

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Smaller hippocampal volumes are associated with earlier birth in preterm neonates.

Mothers' and Fathers' Sensitivity and Children's Cognitive Development in Low-Income, Rural Families

This study examines associations between maternal and paternal sensitive parenting and child cognitive development across the first 3 years of life using longitudinal data from 630 families with co-residing biological mothers and fathers. Sensitive parenting was measured by observational coding of parent-child interactions and child cognitive development was assessed with the Bayley Scales of Infant Development and the Wechsler Preschool and Primary Scales of Intelligence. There were multiple direct and indirect associations between parenting and cognitive development across mothers and fathers, suggesting primary effects, carry-forward effects, spillover effects across parents, and transactional effects across parents and children. Associations between parenting and cognitive development were statistically consistent across mothers and fathers, and the cumulative effects of early parenting on later cognitive development were comparable to the effects of later parenting on later cognitive development. As interpreted through a family systems framework, findings suggest additive and interdependent effects across parents and children.

Cortical morphometry and IQ in VLBW children without cerebral palsy born in 2003-2007

Children born prematurely with very low birth weight (VLBW: bw  ≤ 1500 g) have an increased risk of preterm perinatal brain injury, which may subsequently alter the maturation of the brain, including the cerebral cortex. The aim of study was to assess cortical thickness and surface area in VLBW children compared with term-born controls, and to investigate possible relationships between cortical morphology and Full IQ. In this cross-sectional study, 37 VLBW and 104 term children born between the years 2003–2007 were assessed cognitively at 5–10 years of age, using age appropriate Wechsler tests. The FreeSurfer software was used to obtain estimates of cortical thickness and surface area based on T1-weighted MRI images at 1.5 Tesla. The VLBW children had smaller cortical surface area bilaterally in the frontal, temporal, and parietal lobes. A thicker cortex in the frontal and occipital regions and a thinner cortex in posterior parietal areas were observed in the VLBW group. There were significant differences in Full IQ between groups (VLBW M = 98, SD = 9.71; controls M = 108, SD = 13.57; p < 0.001). There was a positive relationship between IQ and surface area in both groups, albeit significant only in the larger control group. In the VLBW group, reduced IQ was associated with frontal cortical thickening and temporo-parietal thinning.

We conclude that cortical deviations are evident in childhood even in VLBW children born in 2003–2007 who have received state of the art medical treatment in the perinatal period and who did not present with focal brain injuries on neonatal ultrasonography. The cortical deviations were associated with reduced cognitive functioning.

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Cortical deviations are evident even in VLBW children born in 2003–2007

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A smaller surface area was observed in widespread cortical regions in VLBW children

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VLBW children had frontal and occipital cortical thickening and parietal thinning

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VLBW children had reduced Full IQ compared to term born peers

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The cortical deviations were partially associated with reduced cognitive functioning

Test-retest reliability of the Capute scales for neurodevelopmental screening of a high risk sample: Impact of test-retest interval and degree of neonatal risk

AIM

Reliable and valid screening and assessment tools are necessary to identify children at risk for neurodevelopmental disabilities who may require additional services. This study evaluated the test-retest reliability of the Capute Scales in a high-risk sample, hypothesizing adequate reliability across 6- and 12-month intervals.

METHODS

Capute Scales scores (N = 66) were collected via retrospective chart review from a NICU follow-up clinic within a large urban medical center spanning three age-ranges: 12-18, 19-24, and 25-36 months. On average, participants were classified as very low birth weight and premature. Reliability of the Capute Scales was evaluated with intraclass correlation coefficients across length of test-retest interval, age at testing, and degree of neonatal complications.

RESULTS

The Capute Scales demonstrated high reliability, regardless of length of test-retest interval (ranging from 6 to 14 months) or age of participant, for all index scores, including overall Developmental Quotient (DQ), language-based skill index (CLAMS) and nonverbal reasoning index (CAT). Linear regressions revealed that greater neonatal risk was related to poorer test-retest reliability; however, reliability coefficients remained strong.

CONCLUSIONS

The Capute Scales afford clinicians a reliable and valid means of screening and assessing for neurodevelopmental delay within high-risk infant populations.

Functional plasticity in childhood brain disorders: when, what, how, and whom to assess

At every point in the lifespan, the brain balances malleable processes representing neural plasticity that promote change with homeostatic processes that promote stability. Whether a child develops typically or with brain injury, his or her neural and behavioral outcome is constructed through transactions between plastic and homeostatic processes and the environment. In clinical research with children in whom the developing brain has been malformed or injured, behavioral outcomes provide an index of the result of plasticity, homeostasis, and environmental transactions. When should we assess outcome in relation to age at brain insult, time since brain insult, and age of the child at testing? What should we measure? Functions involving reacting to the past and predicting the future, as well as social-affective skills, are important. How should we assess outcome? Information from performance variability, direct measures and informants, overt and covert measures, and laboratory and ecological measures should be considered. In whom are we assessing outcome? Assessment should be cognizant of individual differences in gene, socio-economic status (SES), parenting, nutrition, and interpersonal supports, which are moderators that interact with other factors influencing functional outcome.

Altered Network Oscillations and Functional Connectivity Dynamics in Children Born Very Preterm

Structural brain connections develop atypically in very preterm children, and altered functional connectivity is also evident in fMRI studies. Such alterations in brain network connectivity are associated with cognitive difficulties in this population. Little is known, however, about electrophysiological interactions among specific brain networks in children born very preterm. In the present study, we recorded magnetoencephalography while very preterm children and full-term controls performed a visual short-term memory task. Regions expressing task-dependent activity changes were identified using beamformer analysis, and inter-regional phase synchrony was calculated. Very preterm children expressed altered regional recruitment in distributed networks of brain areas, across standard physiological frequency ranges including the theta, alpha, beta and gamma bands. Reduced oscillatory synchrony was observed among task-activated brain regions in very preterm children, particularly for connections involving areas critical for executive abilities, including middle frontal gyrus. These findings suggest that inability to recruit neurophysiological activity and interactions in distributed networks including frontal regions may contribute to difficulties in cognitive development in children born very preterm.

Neurodevelopmental outcomes in infants and children with single-suture craniosynostosis: a systematic review

Children with single-suture craniosynostosis (SSC) are increasingly considered to be at high risk of adverse neurodevelopmental outcomes. This systematic review aimed to synthesise and critically appraise the existing literature on the neurodevelopmental features of SSC, with particular attention to methodological quality. A total of 33 articles based on 27 cohorts met inclusion criteria. In the context of variable methodological design and quality, most neurodevelopmental studies indicated that children with SSC are at increased risk for difficulties in cognitive, language, and motor domains during infancy (both pre- and post-surgery) and childhood. Limited information exists on factors influencing outcome.

Determining the impact of prenatal tobacco exposure on self-regulation at 6 months

Our goal in the present study was to examine the effects of maternal smoking during pregnancy on infant self-regulation, exploring birth weight as a mediator and sex as a moderator of risk. A prospective sample of 218 infants was assessed at 6 months of age. Infants completed a battery of tasks assessing working memory/inhibition, attention, and emotional reactivity and regulation. Propensity scores were used to statistically control for confounding risk factors associated with maternal smoking during pregnancy. After prenatal and postnatal confounds were controlled, prenatal tobacco exposure was related to reactivity to frustration and control of attention during stimulus encoding. Birth weight did not mediate the effect of prenatal exposure but was independently related to reactivity and working memory/inhibition. The effect of tobacco exposure was not moderated by sex.

Executive functions in very-low-birth-weight young adults: a comparison between self-report and neuropsychological test results

Executive functions are goal-directed control mechanisms that modulate the operation of other cognitive processes. Preterm born very-low-birth-weight (VLBW: birth weight<1500 grams) children have more problems with attention/executive function than their term born peers. The objective of this study is to examine if VLBW young adults had more self-reported attention/ executive problems and lower neuropsychological test results than controls. Furthermore, to investigate the relationship between self-reported attention/executive problems, general cognitive ability (IQ) and test results. Forty-two VLBW [mean birth weight 1237 (219) grams, and gestational age 29.3 (2.4) weeks] and 63 term born controls at age 19 years completed The BRIEF-A self-report of attention/executive functions in everyday life. The Wechsler Adult Intelligence Scale III was used to obtain IQ scores; subtests from Delis-Kaplan were used to assess attention/executive function. There were no differences between the VLBW young adults and controls on any of the BRIEF-A measures, but the VLBW subjects had lower scores on 8 of the 18 neuropsychological subtests (p<.01). Some correlations between BRIEF-A and the Stroop and TMT tests were found in the VLBW group. VLBW young adults do not report more problems regarding attention/executive function in daily life than controls despite lower results on several neuropsychological tests.

Brain injury in premature neonates: A primary cerebral dysmaturation disorder?

With advances in neonatal care, preterm neonates are surviving with an evolving constellation of motor and cognitive disabilities that appear to be related to widespread cellular maturational disturbances that target cerebral gray and white matter. Whereas preterm infants were previously at high risk for destructive brain lesions that resulted in cystic white matter injury and secondary cortical and subcortical gray matter degeneration, contemporary cohorts of preterm survivors commonly display less severe injury that does not appear to involve pronounced glial or neuronal loss. Nevertheless, these milder forms of injury are also associated with reduced cerebral growth. Recent human and experimental studies support that impaired cerebral growth is related to disparate responses in gray and white matter. Myelination disturbances in cerebral white matter are related to aberrant regeneration and repair responses to acute death of premyelinating late oligodendrocyte progenitors (preOLs). In response to preOL death, early oligodendrocyte progenitors rapidly proliferate and differentiate, but the regenerated preOLs fail to normally mature to myelinating cells required for white matter growth. Although immature neurons appear to be more resistant to cell death from hypoxia-ischemia than glia, they display widespread disturbances in maturation of their dendritic arbors, which further contribute to impaired cerebral growth. These complex and disparate responses of neurons and preOLs thus result in large numbers of cells that fail to fully mature during a critical window in development of neural circuitry. These recently recognized forms of cerebral gray and white matter dysmaturation raise new diagnostic challenges and suggest new therapeutic directions centered on reversal of the processes that promote dysmaturation.

Cerebral white and gray matter injury in newborns: new insights into pathophysiology and management

Increasing numbers of preterm neonates survive with motor and cognitive disabilities related to less destructive forms of cerebral injury that still result in reduced cerebral growth. White matter injury results in myelination disturbances related to aberrant responses to death of pre-myelinating oligodendrocytes (preOLs). PreOLs are rapidly regenerated but fail to mature to myelinating cells. Although immature projection neurons are more resistant to hypoxia-ischemia than preOLs, they display widespread disturbances in dendritic arbor maturation, which provides an explanation for impaired cerebral growth. Thus, large numbers of cells fail to fully mature during a critical window in development of neural circuitry. These recently recognized forms of cerebral gray and white matter dysmaturation suggest new therapeutic directions centered on reversal of the processes that promote dysmaturation.

Relation of neural structure to persistently low academic achievement: a longitudinal study of children with differing birth weights

OBJECTIVE

This study examined the relation of cerebral tissue reductions associated with VLBW to patterns of growth in core academic domains.

METHOD

Children born <750 g, 750 to 1,499 g, or >2,500 g completed measures of calculation, mathematical problem solving, and word decoding at time points spanning middle childhood and adolescence. K. A. Espy, H. Fang, D. Charak, N. M. Minich, and H. G. Taylor (2009, Growth mixture modeling of academic achievement in children of varying birth weight risk, Neuropsychology, Vol. 23, pp. 460-474) used growth mixture modeling to identify two growth trajectories (clusters) for each academic domain: an average achievement trajectory and a persistently low trajectory. In this study, 97 of the same participants underwent magnetic resonance imaging (MRI) in late adolescence, and cerebral tissue volumes were used to predict the probability of low growth cluster membership for each domain.

RESULTS

Adjusting for whole brain volume (wbv), each 1-cm(3) reduction in caudate volume was associated with a 1.7- to 2.1-fold increase in the odds of low cluster membership for each domain. Each 1-mm(2) decrease in corpus callosum surface area increased these odds approximately 1.02-fold. Reduced cerebellar white matter volume was associated specifically with low calculation and decoding growth, and reduced cerebral white matter volume was associated with low calculation growth. Findings were similar when analyses were confined to the VLBW groups.

CONCLUSIONS

Reduced volume of structures involved in connectivity, executive attention, and motor control may contribute to heterogeneous academic trajectories among children with VLBW.

Regional white matter microstructure in very preterm infants: predictors and 7 year outcomes

The aims of this study were to investigate regional white matter microstructural differences between very preterm (VPT) (<30 weeks' gestational age and/or <1250 g) and full term (FT) (≥37 weeks' gestational age) infants at term corrected age with diffusion tensor imaging, and to explore perinatal predictors of diffusion measures, and the relationship between regional diffusion measures and neurodevelopmental outcomes at age 7 years in VPT children. Mean (MD) (p = .003), axial (AD) (p = .008), and radial diffusivity (RD) (p = .003) in total white matter were increased in VPT compared with FT infants, with similar fractional anisotropy (FA) in the two groups. There was little evidence that group-wise differences were specific to any of the 8 regions studied for each hemisphere. Perinatal white matter abnormality and intraventricular hemorrhage (grade III or IV) were associated with increased diffusivity in the white matter of VPT infants. Higher white matter diffusivity measures of the inferior occipital and cerebellar region at term-equivalent age were associated with increased risk of impairments in motor and executive function at 7 years in VPT children, but there was little evidence for associations with IQ or memory impairment. In conclusion, myelination is likely disrupted or delayed in VPT infants, especially those with perinatal brain abnormality (BA). Altered diffusivity at term-equivalent age helps explain impaired functioning at 7 years. This study defines the nature of microstructural alterations in VPT infant white matter, assists in understanding the associated risk factors, and is the first study to reveal an important link between inferior occipital and cerebellar white matter disorganization in infancy, and executive and motor functioning 7 years later.

Region-Specific Slowing of Alpha Oscillations is Associated with Visual-Perceptual Abilities in Children Born Very Preterm

Children born very preterm (≤32 weeks gestational age) without major intellectual or neurological impairments often express selective deficits in visual-perceptual abilities. The alterations in neurophysiological development underlying these problems, however, remain poorly understood. Recent research has indicated that spontaneous alpha oscillations are slowed in children born very preterm, and that atypical alpha-mediated functional network connectivity may underlie selective developmental difficulties in visual-perceptual ability in this group. The present study provides the first source-resolved analysis of slowing of spontaneous alpha oscillations in very preterm children, indicating alterations in a distributed set of brain regions concentrated in areas of posterior parietal and inferior temporal regions associated with visual perception, as well as prefrontal cortical regions and thalamus. We also uniquely demonstrate that slowing of alpha oscillations is associated with selective difficulties in visual-perceptual ability in very preterm children. These results indicate that region-specific slowing of alpha oscillations contribute to selective developmental difficulties prevalent in this population.