Latent mean differences in executive function in at-risk preterm children: the delay-deficit dilemma

Effect of biomedical complications on very and extremely preterm children's language

Introduction

Very and extremely preterm children have been found to show delays in the development of language in early years. In some investigations, however, a rigorous control of biomedical complications, such as Periventricular Leukomalacia (PVL), Intraventricular Hemorrhage (IVH) or Bronchopulmonary Dysplasia (BPD), does not always exist. For that reason, a confounding effect of low gestational age and biomedical complications may lead to erroneous conclusions about the effect of gestational age.

Methods

In this investigation we compare language development [use of words, sentence complexity and mean length of the three longest utterances (MLU3)] of three groups of Chilean children at 24 months of age (corrected age for preterm children). The first group was composed of 42 healthy full-term children (Full term group: FT), the second group of 60 preterm children born below 32 gestational weeks without medical complications (low risk preterm group: LRPT), and the third group was composed of 64 children below 32 gestational weeks who had medical complications (High risk preterm group: HRPT). The three groups were similar in terms of gender distribution, maternal education, and socio-economic environment. The instrument used to assess language was the Communicative Development Inventories (CDI). In addition, the Ages and Stages Questionnaire-3 (ASQ-3) was also used to assess other developmental dimensions.

Results

The results indicate that HRPT and LRPT children obtained significantly lower results than the FT group in the three language measures obtained through the CDI. No significant differences were observed between the HRPT and the LRPT groups, although the HRPT obtained the lowest results in the three CDI measures. The results obtained through the administration of the ASQ-3 confirm the delay of both preterm groups in communicative development when compared to the FT group. No significant differences between the FT and the PT groups were observed in gross motor, fine motor and problem solving dimensions of the ASQ-3. The LRPT group obtained results that were significantly higher than those of the FT group and the HRPT group in gross motor development.

Discussion

These results seem to indicate that the area of language development is particularly influenced by very or extremely low gestational age.

Pediatric Critical Care Outcomes: State of the Science

Children who survive the pediatric intensive care unit (PICU) are at risk of developing post-intensive care syndrome in pediatrics (PICS-p). PICS-p, defined as new physical, cognitive, emotional, and/or social health dysfunction following critical illness, can affect the child and family. Historically, synthesizing PICU outcomes research has been challenging due to inconsistency in study design and in outcomes measurement. PICS-p risk may be mitigated by implementing intensive care unit best practices that limit iatrogenic injury and by supporting the resiliency of critically ill children and their families.

Quantitative Meta-analyses of Cognitive Abilities in Children With Pediatric-onset Multiple Sclerosis

Pediatric-onset multiple sclerosis (POMS), is the manifestation of multiple sclerosis in individuals before 18 years of age. About a third of children with POMS show some form of lower cognitive performance. The purpose of this study is to examine using quantitative meta-analyses the effect size of altered performance between children with and without POMS on overall intelligence quotient (IQ), information processing speed, and language functions. We searched the literature for studies that reported scores on cognitive tests administered to children with and without POMS. Studies were systematically reviewed using PRISMA guidelines. We analyzed data from 14 studies that examined 1283 children with and without POMS when cognitive categories consisted of five or more studies. Effect sizes, publication bias and potential confounds were considered. Significant cognitive differences are revealed for all categories with the strongest effect observed for overall IQ. A moderate effect is observed for information processing speed, and small effects for verbal fluency and verbal memory. Cognitive abilities present differently in children with POMS and a better understanding of this manifestation will inform intervention and remediation tools that can improve clinical and educational practice for the benefit of children with POMS.

Cognitive and Learning Outcomes in Late Preterm Infants at School Age: A Systematic Review

Late preterm children born between 34^0/7 and 36^6/7 weeks’ gestation account for ≈70% of prematurely born infants. There is growing concern about this population at risk of mild neurodevelopmental problems, learning disabilities and lower academic performance. Following the Preferred Reporting Items for Systematic Review and Meta-Analysis (PRISMA) statement, this paper analyzes recent published evidence from 16selected studies involving late preterm children and control group assessments at preschool and/or school age, mainly focusing on cognitive functioning, language learning and academic achievement. The review identifies the assessment tools used in these studies (standardized tests, parental questionnaires and laboratory tasks) and the areas being evaluated from preschool (age 3 years) to primary school levels. Results reveal the presence of mild difficulties, pointing to suboptimal outcomes in areas such as executive function, short term verbal memory, literacy skills, attention and processing speed. Some difficulties are transient, but others persist, possibly compromising academic achievement, as suggested by the few studies reporting on higher risk for poor school performance. Given the increasing number of late preterm children in our society the review highlights the need to implement screening strategies to facilitate early risk detection and minimize the negative effects of this morbidity in childhood.

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.

Inhibition is associated with whole-brain structural brain connectivity on network level in school-aged children born very preterm and at term

Inhibition abilities are often impaired in children born very preterm. In typically-developing individuals, inhibition has been associated with structural brain connectivity (SC). As SC is frequently altered following preterm birth, this study investigated whether aberrant SC underlies inhibition deficits in school-aged children born very preterm. In a group of 67 very preterm participants aged 8-13 years and 69 term-born peers, inhibition abilities were assessed with two tasks. In a subgroup of 50 very preterm and 62 term-born participants, diffusion tensor imaging (DTI) data were collected. Using network-based statistics (NBS), mean fractional anisotropy (FA_mean) was compared between groups. Associations of FA_mean and inhibition abilities were explored through linear regression. The composite score of inhibition abilities was lower in the very preterm group (M ​= ​-0.4, SD ​= ​0.8) than in the term-born group (M ​= ​0.0, SD ​= ​0.8) but group differences were not significant when adjusting for age, sex and socio-economic status (β ​= ​-0.13, 95%-CI [-0.30, 0.04], p ​= ​0.13). In the very preterm group, FA_mean was significantly lower in a network comprising thalamo-frontal, thalamo-temporal, frontal, cerebellar and intra-hemispheric connections than in the term-born group (t ​= ​5.21, lowest p-value ​= ​0.001). Irrespective of birth status, a network comprising parietal, cerebellar and subcortical connections was positively associated with inhibition abilities (t ​= ​4.23, lowest p-value ​= ​0.02). Very preterm birth results in long-term alterations of SC at network-level. As networks underlying inhibition abilities do not overlap with those differing between the groups, FA_mean may not be adequate to explain inhibition problems in very preterm children. Future studies should combine complementary measures of brain connectivity to address neural correlates of inhibition abilities.

Executive function deficits in children born preterm or at low birthweight: a meta-analysis

AIM

To investigate the magnitude of executive function deficits and their dependency on gestational age, sex, age at assessment, and year of birth for children born preterm and/or at low birthweight.

METHOD

PubMed, PsychINFO, Web of Science, and ERIC were searched for studies reporting on executive functions in children born preterm/low birthweight and term controls born in 1990 and later, assessed at a mean age of 4 years or higher. Studies were included if five or more studies reported on the same executive function measures.

RESULTS

Thirty-five studies (3360 children born preterm/low birthweight, 2812 controls) were included. Children born preterm/low birthweight performed 0.5 standardized mean difference (SMD) lower on working memory and cognitive flexibility and 0.4 SMD lower on inhibition. SMDs for these executive functions did not significantly differ from each other. Meta-regression showed that heterogeneity in SMDs for working memory and inhibition could not be explained by study differences in gestational age, sex, age at assessment, or year of birth.

INTERPRETATION

Children born preterm/low birthweight since 1990 perform half a SMD below term-born peers on executive function, which does not seem to improve with more recent advances in medical care or with increasing age.

WHAT THIS PAPER ADDS

Children born preterm/low birthweight perform below term-born children on core executive functions. Lower gestational age or male sex are not risk factors for poorer executive functions. Executive function difficulties in children born preterm/low birthweight remain stable across childhood. Executive function difficulties are similar for children born recently and children born in earlier eras.

Effects of extreme prematurity and kindergarten neuropsychological skills on early academic progress

OBJECTIVE

The study was designed to investigate the effect of extreme prematurity on growth in academic achievement across the early school years and the validity of kindergarten neuropsychological skills as predictors of achievement.

METHOD

A 2001-2003 birth cohort of 145 extremely preterm/extremely low birth weight (EPT/ELBW) children from a single medical center, along with 111 normal birth weight (NBW) classmate controls, were recruited during their first year in kindergarten and followed annually across the next 2 years in school. Mixed model analysis was conducted to compare the groups on growth in achievement across years and examine kindergarten neuropsychological skills as predictors of growth.

RESULTS

The EPT/ELBW group scored significantly below NBW controls on all achievement tests across years and had higher rates of special education placement and grade repetition. Despite limited catch-up of the EPT/ELBW group to the NBW controls in spelling, group differences were generally stable. Differences in spelling and mathematics achievement remained significant when controlling for global intelligence or excluding children who had intellectual or neurosensory impairments or repeated a grade. Higher scores on kindergarten tests of multiple neuropsychological ability domains predicted higher achievement levels and steeper growth in achievement.

CONCLUSIONS

The findings document persistent academic weaknesses in EPT/ELBW children across the early school years. Results point to the need for preschool interventions to enhance academic readiness and suggest that neuropsychological skills assessed in kindergarten are useful in identifying individual differences in early learning progress. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Rapid Infant Prefrontal Cortex Development and Sensitivity to Early Environmental Experience

Over the last fifteen years, the emerging field of developmental cognitive neuroscience has described the relatively late development of prefrontal cortex in children and the relation between gradual structural changes and children's protracted development of prefrontal-dependent skills. Widespread recognition by the broader scientific community of the extended development of prefrontal cortex has led to the overwhelming perception of prefrontal cortex as a "late developing" region of the brain. However, despite its supposedly protracted development, multiple lines of research have converged to suggest that prefrontal cortex development may be particularly susceptible to individual differences in children's early environments. Recent studies demonstrate that the impacts of early adverse environments on prefrontal cortex are present very early in development: within the first year of life. This review provides a comprehensive overview of new neuroimaging evidence demonstrating that prefrontal cortex should be characterized as a "rapidly developing" region of the brain, discusses the converging impacts of early adversity on prefrontal circuits, and presents potential mechanisms via which adverse environments shape both concurrent and long-term measures of prefrontal cortex development. Given that environmentally-induced disparities are present in prefrontal cortex development within the first year of life, translational work in intervention and/or prevention science should focus on intervening early in development to take advantages of this early period of rapid prefrontal development and heightened plasticity.

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.

Neuropsychological Outcomes in Extremely Preterm Preschoolers Exposed to Tiered Low Oxygen Targets: An Observational Study

An observational study of neuropsychological outcomes at preschool age of tiered lowered oxygen (O2) saturation targets in extremely preterm neonates. We studied 111 three-year-olds born <28 weeks' gestational age. Fifty-nine participants born in 2009-2010 during a time-limited quality improvement initiative each received three-tiered stratification of oxygen rates (83-93% until age 32 weeks, 85-95% until age 35 weeks, and 95% after age 35 weeks), the TieredO2 group. Comparisons were made with 52 participants born in 2007-2008 when pre-initiative saturation targets were non-tiered at 89-100%, the Non-tieredO2 group. Neuropsychological domains included general intellectual, executive, attention, language, visuoperceptual, visual-motor, and fine and gross motor functioning. Descriptive and inferential analyses were conducted. Group comparisons were not statistically significant. Descriptively, the TieredO2 group had better general intellectual, executive function, visual-motor, and motor performance and the Non-tieredO2 group had better language performance. Cohen's d and confidence intervals around d were in similar direction and magnitude across measures. A large effect size was found for recall of digits-forward in participants born at 23 and 24 weeks' gestation, d=0.99 and 1.46, respectively. Better TieredO2 outcomes in all domains except language suggests that the tiered oxygen saturation target method is not harmful and merits further investigation through further studies. Benefit in auditory attention appeared greatest in those born at 23 and 24 weeks. Participants in the tiered oxygen saturation group also had fewer ventilation days and a lower incidence of bronchopulmonary dysplasia, perhaps explanatory for these neuropsychological outcomes at age 3.

Relation of perinatal risk and early parenting to executive control at the transition to school

Executive control (EC) develops rapidly during the preschool years and is central to academic achievement and functional outcome. Although children with perinatal adversity are at known risk for EC impairments, little is known about the underlying nature of these impairments or the mechanisms that contribute to their development over time. Drawing on a cohort of 110 high-risk children born very preterm (VPT; < 33 weeks / < 1500 g) and 113 healthy full-term children, this study examined the implications of perinatal adversity and early parenting for children's EC as they transitioned to formal schooling. Parent supportive presence, intrusiveness, and parent-child synchrony were observed during a series of problem-solving tasks at ages 2 and 4 years. At age 6, children completed a comprehensive battery of EC tasks. Academic outcomes were assessed at age 9. The VPT group showed global EC impairments at age 6, although the unitary factor that best characterized the structure of EC was the same in both groups. High-risk dyads were characterized by more intrusive and less synchronous parent-child interactions in early childhood, which in turn predicted poorer child EC at age 6. EC partially mediated the relation of risk status to poorer academic achievement at age 9. Findings demonstrate the cumulative effects of perinatal adversity on children's EC in the crucial transition to schooling. They also highlight the importance of the parent-child relationship as a target for intervention efforts to help mitigate these effects.