Extensive and interrelated subcortical white and gray matter alterations in preterm-born adults

Brain gray and white matter abnormalities in preterm-born adolescents: A meta-analysis of voxel-based morphometry studies

Introduction

Studies using voxel-based morphometry report variable and inconsistent abnormalities of gray matter volume (GMV) and white matter volume (WMV) in brains of preterm-born adolescents (PBA). In such circumstances a meta-analysis can help identify the most prominent and consistent abnormalities.

Method

We identified 9 eligible studies by systematic search of the literature up to October 2017. We used Seed-based d Mapping to analyze GMV and WMV alterations between PBA and healthy controls.

Results

In the GMV meta-analysis, PBA compared to healthy controls showed: increased GMV in left cuneus cortex, left superior frontal gyrus, and right anterior cingulate cortex; decreased GMV in bilateral inferior temporal gyrus (ITG), left superior frontal gyrus, and right caudate nucleus. In the WMV meta-analysis, PBA showed: increased WMV in right fusiform gyrus and precuneus; decreased WMV in bilateral ITG, and right inferior frontal gyrus. In meta-regression analysis, the percentage of male PBA negatively correlated with decreased GMV of bilateral ITG.

Interpretation

PBA show widespread GMV and WMV alterations in the default mode network, visual recognition network, and salience network. These changes may be causally relevant to socialization difficulties and cognitive impairments. The meta-regression results perhaps reveal the structural underpinning of the cognition-related sex differences in PBA.

The Microbiome and Preterm Birth: A Change in Paradigm with Profound Implications for Pathophysiologic Concepts and Novel Therapeutic Strategies

Preterm birth poses a global challenge with a continuously increasing disease burden during the last decades. Advances in understanding the etiopathogenesis did not lead to a reduction of prematurely born infants so far. A balanced development of the host microbiome in early life is key for the maturation of the immune system and many other physiological functions. With the tremendous progress in new diagnostic possibilities, the contribution of microbiota changes to preterm birth and the acute and long-term sequelae of prematurity have come into the research focus. This review summarizes the latest advances in the understanding of microbiomes in the amniotic cavity and the female lower genital tract and how changes in microbiota structures contribute to preterm delivery. The exhibition of these highly vulnerable infants to the hostile environment in the neonatal intensive care unit necessarily entails the rapid colonization with a nonbalanced microbiome in a situation where the organism is still very prone and at an early stage of development. The global research efforts to decipher pathologic changes will pave the way to new pre- and postnatal therapeutic concepts.

Decreased BOLD fluctuations in lateral temporal cortices of premature born adults

Lasting volume reductions in subcortical and temporal-insular cortices after premature birth suggest altered ongoing activity in these areas. We hypothesized altered fluctuations in ongoing neural excitability and activity, as measured by slowly fluctuating blood oxygenation of resting-state functional MRI (rs-fMRI), in premature born adults, with altered fluctuations being linked with underlying brain volume reductions. To investigate this hypothesis, 94 very preterm/very low birth weight (VP/VLBW) and 92 full-term born young adults underwent structural and rs-fMRI data acquisition with voxel-based morphometry and amplitude of low-frequency fluctuations (ALFF) as main outcome measure. In VP/VLBW adults, ALFF was reduced in lateral temporal cortices, and this reduction was positively associated with lower birth weight. Regions of reduced ALFF overlapped with reduced brain volume. On the one hand, ALFF reduction remained after controlling for volume loss, supporting the functional nature of ALFF reductions. On the other hand, ALFF decreases were positively associated with underlying brain volume loss, indicating a relation between structural and functional changes. Furthermore, within the VP/VLBW group, reduced ALFF was associated with reduced IQ, indicating the behavioral relevance of ALFF decreases in temporal cortices. These results demonstrate long-term impact of premature birth on ongoing BOLD fluctuations in lateral temporal cortices, which are linked with brain volume reductions. Data suggest permanently reduced fluctuations in ongoing neural excitability and activity in structurally altered lateral temporal cortices after premature birth.

Enhanced autophagy contributes to excitotoxic lesions in a rat model of preterm brain injury

Cystic periventricular leukomalacia is commonly diagnosed in premature infants, resulting from severe hypoxic-ischemic white matter injury, and also involving some grey matter damage. Very few is known concerning the cell death pathways involved in these types of premature cerebral lesions. Excitotoxicity is a predominant mechanism of hypoxic-ischemic injury in the developing brain. Concomitantly, it has been recently shown that autophagy could be enhanced in excitotoxic conditions switching this physiological intracellular degradation system to a deleterious process. We here investigated the role of autophagy in a validated rodent model of preterm excitotoxic brain damage mimicking in some aspects cystic periventricular leukomalacia. An excitotoxic lesion affecting periventricular white and grey matter was induced by injecting ibotenate, a glutamate analogue, in the subcortical white matter (subcingulum area) of five-day old rat pups. Ibotenate enhanced autophagy in rat brain dying neurons at 24 h as shown by increased presence of autophagosomes (increased LC3-II and LC3-positive dots) and enhanced autophagic degradation (SQSTM1 reduction and increased number and size of lysosomes (LAMP1- and CATHEPSIN B-positive vesicles)). Co-injection of the pharmacological autophagy inhibitor 3-methyladenine prevented not only autophagy induction but also CASPASE-3 activation and calpain-dependent cleavage of SPECTRIN 24 h after the insult, thus providing a strong reduction of the long term brain injury (16 days after ibotenate injection) including lateral ventricle dilatation, decreases in cerebral tissue volume and in subcortical white matter thickness. The autophagy-dependent neuroprotective effect of 3-methyladenine was confirmed in primary cortical neuronal cultures using not only pharmacological but also genetic autophagy inhibition of the ibotenate-induced autophagy. Strategies inhibiting autophagy could then represent a promising neuroprotective approach in the context of severe preterm brain injuries.

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

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

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.

Models for Preterm Cortical Development Using Non Invasive Clinical EEG

The objective of this study was to evaluate the piglet and the mouse as model systems for preterm cortical development. According to the clinical context, we used non invasive EEG recordings. As a prerequisite, we developed miniaturized Ag/AgCl electrodes for full band EEG recordings in mice and verified that Urethane had no effect on EEG band power. Since mice are born with a “preterm” brain, we evaluated three age groups: P0/P1, P3/P4 and P13/P14. Our aim was to identify EEG patterns in the somatosensory cortex which are distinguishable between developmental stages and represent a physiologic brain development. In mice, we were able to find clear differences between age groups with a simple power analysis of EEG bands and also for phase locking and power spectral density. Interhemispheric coherence between corresponding regions can only be seen in two week old mice. The canolty maps for piglets as well as for mice show a clear PAC (phase amplitude coupling) pattern during development. From our data it can be concluded that analytic tools relying on network activity, as for example PAC (phase amplitude coupling) are best suited to extract basic EEG patterns of cortical development across species.

Complex interactions between hypoxia-ischemia and inflammation in preterm brain injury

Children surviving preterm birth have a high risk of disability, particularly cognitive and learning problems. There is extensive clinical and experimental evidence that disability is now primarily related to dysmaturation of white and gray matter, defined by failure of oligodendrocyte maturation and neuronal dendritic arborization, rather than cell death alone. The etiology of this dysmaturation is multifactorial, with contributions from hypoxia-ischemia, infection/inflammation and barotrauma. Intriguingly, these factors can interact to both increase and decrease damage. In this review we summarize preclinical and clinical evidence that all of these factors trigger secondary or chronic inflammation and gliosis. Thus, we hypothesize that these shared pathological features play a key role in a final common pathway that leads to the impaired neural maturation and connectivity and cognitive/motor impairments that are commonly observed in infants born preterm. This raises the possibility that secondary or chronic inflammation may be a viable therapeutic target for delayed interventions to improve neurodevelopmental outcomes after preterm birth.

WHAT THIS PAPER ADDS

Hypoxia-ischemia, infection/inflammation, and barotrauma/volutrauma all contribute to preterm brain injury. Multiple different triggers of preterm brain injury are associated with central nervous system dysmaturation. Secondary brain inflammation may be a viable target to improve neurodevelopment after preterm birth.

Glia and hemichannels: key mediators of perinatal encephalopathy

Perinatal encephalopathy remains a major cause of disability, such as cerebral palsy. Therapeutic hypothermia is now well established to partially reduce risk of disability in late preterm/term infants. However, new and complementary therapeutic targets are needed to further improve outcomes. There is increasing evidence that glia play a key role in neural damage after hypoxia-ischemia and infection/inflammation. In this review, we discuss the role of astrocytic gap junction (connexin) hemichannels in the spread of neural injury after hypoxia-ischemia and/or infection/inflammation. Potential mechanisms of hemichannel mediated injury likely involve impaired intracellular calcium handling, loss of blood-brain barrier integrity and release of adenosine triphosphate (ATP) resulting in over-activation of purinergic receptors. We propose the hypothesis that inflammation-induced opening of connexin hemichannels is a key regulating event that initiates a vicious cycle of excessive ATP release, which in turn propagates activation of purinergic receptors on microglia and astrocytes. This suggests that developing new neuroprotective strategies for preterm infants will benefit from a detailed understanding of glial and connexin hemichannel responses.

Mood and anxiety disorders in very preterm/very low-birth weight individuals from 6 to 26 years

BACKGROUND

Very preterm (<32 weeks' gestational age; VP) or very low-birth weight (<1,500 g; VLBW) birth has been associated with increased risk for anxiety and mood disorders and less partnering in adulthood. The aim was to test whether (a) VP/VLBW are at increased risk of any anxiety or mood disorders from 6 to 26 years compared with term-born individuals; (b) social support from romantic partners is associated with protection from anxiety and mood disorders; and (c) VP/VLBW adults' lower social support mediates their risk for any anxiety and mood disorders.

METHODS

Data are from a prospective geographically defined longitudinal whole-population study in South Bavaria (Germany). Two hundred VP/VLBW and 197 term individuals were studied from birth to adulthood. Anxiety and mood disorders were assessed at 6, 8, and 26 years with standardized diagnostic interviews and social support via self-report at age 26.

RESULTS

At age 6, VP/VLBW children were not at increased risk of any anxiety or mood disorder. At age 8, VP/VLBW more often had any anxiety disorder than term comparisons (11.8% vs. 6.6%, OR = 2.10, 95% CI [1.08-4.10]). VP/VLBW adults had an increased risk for any mood (27.5% vs. 18.8%, OR = 1.65 [1.02-2.67]) but not for any anxiety disorder (33.0% vs. 28.4%, OR = 1.27 [0.82-1.96]). None of the significant differences survived correction for multiple testing. Social support was associated with a lower risk of anxiety or mood disorders in both groups (OR = 0.81 [0.68-0.96]) and mediated the association of VP/VLBW birth with any anxiety or any mood disorders at age 26.

CONCLUSIONS

This study does not show a persistently increased risk for any anxiety or mood disorder after VP/VLBW birth. Low social support from a romantic partner mediates the risk for anxiety or mood disorders after VP/VLBW birth.

White matter alterations and their associations with motor function in young adults born preterm with very low birth weight

Very low birth weight (VLBW: ≤ 1500 g) individuals have an increased risk of white matter alterations and neurodevelopmental problems, including fine and gross motor problems. In this hospital-based follow-up study, the main aim was to examine white matter microstructure and its relationship to fine and gross motor function in 31 VLBW young adults without cerebral palsy compared with 31 term-born controls, at mean age 22.6 ± 0.7 years. The participants were examined with tests of fine and gross motor function (Trail Making Test-5: TMT-5, Grooved Pegboard, Triangle from Movement Assessment Battery for Children-2: MABC-2 and High-level Mobility Assessment Tool: HiMAT) and diffusion tensor imaging (DTI). Probabilistic tractography of motor pathways of the corticospinal tract (CST) and corpus callosum (CC) was performed. Fractional anisotropy (FA) was calculated in non-crossing (capsula interna in CST, body of CC) and crossing (centrum semiovale) fibre regions along the tracts and examined for group differences. Associations between motor test scores and FA in the CST and CC were investigated with linear regression. Tract-based spatial statistics (TBSS) was used to examine group differences in DTI metrics in all major white matter tracts. The VLBW group had lower scores on all motor tests compared with controls, however, only statistically significant for TMT-5. Based on tractography, FA in the VLBW group was lower in non-crossing fibre regions and higher in crossing fibre regions of the CST compared with controls. Within the VLBW group, poorer fine motor function was associated with higher FA in crossing fibre regions of the CST, and poorer bimanual coordination was additionally associated with lower FA in crossing fibre regions of the CC. Poorer gross motor function was associated with lower FA in crossing fibre regions of the CST and CC. There were no associations between motor function and FA in non-crossing fibre regions of the CST and CC within the VLBW group. In the TBSS analysis, the VLBW group had lower FA and higher mean diffusivity compared with controls in all major white matter tracts. The findings in this study may indicate that the associations between motor function and FA are caused by other tracts crossing the CST and CC, and/or by alterations in the periventricular white matter in the centrum semiovale. Some of the associations were in the opposite direction than hypothesized, thus higher FA does not always indicate better function. Furthermore, widespread white matter alterations in VLBW individuals persist into young adulthood.

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Motor function was associated with FA in crossing fibre regions of CST and CC in VLBW young adults

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In crossing fibre regions of CST, FA was higher in VLBW than in control young adults

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TBSS showed lower FA and higher MD in white matter tracts in VLBW than in control young adults

Adults born preterm: a review of general health and system-specific outcomes

In this review of 126 publications, we report that an overwhelming majority of adults born at preterm gestations remain healthy and well. However, a small, but a significant fraction of them remain at higher risk for neurological, personality and behavioural abnormalities, cardio-pulmonary functional limitations, systemic hypertension and metabolic syndrome compared to their term-born counterparts. The magnitude of increased risk differed across organ systems and varied across reports. The risks were proportional to the degree of prematurity at birth and seemed to occur more frequently among preterm infants born in the final two decades of the 20th century and later. These findings have considerable public health and clinical practice relevance.

CONCLUSION

Preterm birth needs to be considered a chronic condition, with a slight increase in the risk for long-term morbidities among adults born preterm. Therefore, obtaining a history of gestational age and weight at birth should be a routine part of care for patients of all age groups.

Effects of gestational age on brain volume and cognitive functions in generally healthy very preterm born children during school-age: A voxel-based morphometry study

Objective

To determine whether the relationship of gestational age (GA) with brain volumes and cognitive functions is linear or whether it follows a threshold model in preterm and term born children during school-age.

Study design

We studied 106 children (M = 10 years 1 month, SD = 16 months; 40 females) enrolled in primary school: 57 were healthy very preterm children (10 children born 24–27 completed weeks’ gestation (extremely preterm), 14 children born 28–29 completed weeks’ gestation, 19 children born 30–31 completed weeks’ gestation (very preterm), and 14 born 32 completed weeks’ gestation (moderately preterm)) all born appropriate for GA (AGA) and 49 term-born children. Neuroimaging involved voxel-based morphometry with the statistical parametric mapping software. Cognitive functions were assessed with the WISC-IV. General Linear Models and multiple regressions were conducted controlling age, sex, and maternal education.

Results

Compared to groups of children born 30 completed weeks’ gestation and later, children born <28 completed weeks’ gestation had less gray matter volume (GMV) and white matter volume (WMV) and poorer cognitive functions including decreased full scale IQ, and processing speed. Differences in GMV partially mediated the relationship between GA and full scale IQ in preterm born children.

Conclusions

In preterm children who are born AGA and without major complications GA is associated with brain volume and cognitive functions. In particular, decreased brain volume becomes evident in the extremely preterm group (born <28 completed weeks’ gestation). In preterm children born 30 completed weeks’ gestation and later the relationship of GA with brain volume and cognitive functions may be less strong as previously thought.

Reduced Cholinergic Basal Forebrain Integrity Links Neonatal Complications and Adult Cognitive Deficits After Premature Birth

BACKGROUND

Prematurely born individuals have an increased risk for long-term neurocognitive impairments. In animal models, development of the cholinergic basal forebrain (cBF) is selectively vulnerable to adverse effects of perinatal stressors, and impaired cBF integrity results in lasting cognitive deficits. We hypothesized that cBF integrity is impaired in prematurely born individuals and mediates adult cognitive impairments associated with prematurity.

METHODS

We used magnetic resonance imaging-based volumetric assessments of a cytoarchitectonically defined cBF region of interest to determine differences in cBF integrity between 99 adults who were born very preterm and/or with very low birth weight and 106 term-born control subjects from the same birth cohort. Magnetic resonance imaging-derived cBF volumes were studied in relation to neonatal clinical complications after delivery and intelligence measures (IQ) in adulthood.

RESULTS

In adults who were born very preterm and/or with very low birth weight, cBF volumes were significantly reduced compared with term-born adults (-4.5% [F_1,202 = 11.82, p = .001]). Lower cBF volume in adults who were born very preterm and/or with very low birth weight was specifically associated with both neonatal complications (r_part,92 = -.35, p < .001) and adult IQ (r_part,88 = .33, p = .001) even after controlling for global gray matter and white matter volume. In a path analytic model, cBF volume significantly mediated the association between neonatal complications and adult cognitive deficits.

CONCLUSIONS

We provide first-time evidence in humans that cBF integrity is impaired after premature birth and links neonatal complications with long-term cognitive outcome. Data suggest that cholinergic system abnormalities may play a relevant role for long-term neurocognitive impairments associated with premature delivery.

Ventricular shape and relative position abnormalities in preterm neonates

Recent neuroimaging findings have highlighted the impact of premature birth on subcortical development and morphological changes in the deep grey nuclei and ventricular system. To help characterize subcortical microstructural changes in preterm neonates, we recently implemented a multivariate tensor-based method (mTBM). This method allows to precisely measure local surface deformation of brain structures in infants. Here, we investigated ventricular abnormalities and their spatial relationships with surrounding subcortical structures in preterm neonates. We performed regional group comparisons on the surface morphometry and relative position of the lateral ventricles between 19 full-term and 17 preterm born neonates at term-equivalent age. Furthermore, a relative pose analysis was used to detect individual differences in translation, rotation, and scale of a given brain structure with respect to an average. Our mTBM results revealed broad areas of alterations on the frontal horn and body of the left ventricle, and narrower areas of differences on the temporal horn of the right ventricle. A significant shift in the rotation of the left ventricle was also found in preterm neonates. Furthermore, we located significant correlations between morphology and pose parameters of the lateral ventricles and that of the putamen and thalamus. These results show that regional abnormalities on the surface and pose of the ventricles are also associated with alterations on the putamen and thalamus. The complementarity of the information provided by the surface and pose analysis may help to identify abnormal white and grey matter growth, hinting toward a pattern of neural and cellular dysmaturation.

A longitudinal study of associations between psychiatric symptoms and disorders and cerebral gray matter volumes in adolescents born very preterm

Background

Being born preterm with very low birthweight (VLBW ≤ 1500 g) poses a risk for cortical and subcortical gray matter (GM) abnormalities, as well as for having more psychiatric problems during childhood and adolescence than term-born individuals. The aim of this study was to investigate the relationship between cortical and subcortical GM volumes and the course of psychiatric disorders during adolescence in VLBW individuals.

Methods

We followed VLBW individuals and term-born controls (birth weight ≥10th percentile) from 15 (VLBW;controls n = 40;56) to 19 (n = 44;60) years of age. Of these, 30;37 individuals were examined longitudinally. Cortical and subcortical GM volumes were extracted from MRPRAGE images obtained with the same 1.5 T MRI scanner at both time points and analyzed at each time point with the longitudinal stream of the FreeSurfer software package 5.3.0. All participants underwent clinical interviews and were assessed for psychiatric symptoms and diagnosis (Schedule for Affective Disorders and Schizophrenia for School-age Children, Children’s Global Assessment Scale, Attention-Deficit/Hyperactivity Disorder Rating Scale-IV). VLBW adolescents were divided into two groups according to diagnostic status from 15 to 19 years of age: persisting/developing psychiatric diagnosis or healthy/becoming healthy.

Results

Reduction in subcortical GM volume at 15 and 19 years, not including the thalamus, was limited to VLBW adolescents with persisting/developing diagnosis during adolescence, whereas VLBW adolescents in the healthy/becoming healthy group had similar subcortical GM volumes to controls. Moreover, across the entire VLBW group, poorer psychosocial functioning was predicted by smaller subcortical GM volumes at both time points and with reduced GM volume in the thalamus and the parietal and occipital cortex at 15 years. Inattention problems were predicted by smaller GM volumes in the parietal and occipital cortex.

Conclusions

GM volume reductions in the parietal and occipital cortex as well as smaller thalamic and subcortical GM volumes were associated with the higher rates of psychiatric symptoms found across the entire VLBW group. Significantly smaller subcortical GM volumes in VLBW individuals compared with term-born peers might pose a risk for developing and maintaining psychiatric diagnoses during adolescence. Future research should explore the possible role of reduced cortical and subcortical GM volumes in the pathogenesis of psychiatric illness in VLBW adolescents.

Electronic supplementary material

The online version of this article (doi:10.1186/s12887-017-0793-0) contains supplementary material, which is available to authorized users.

Neonatal treatment philosophy in Dutch and German NICUs: health-related quality of life in adulthood of VP/VLBW infants

PURPOSE

Although survival after very preterm birth (VP)/very low birth weight (VLBW) has improved, a significant number of VP/VLBW individuals develop physical and cognitive problems during their life course that may affect their health-related quality of life (HRQoL). We compared HRQoL in VP/VLBW cohorts from two countries: The Netherlands (n = 314) versus Germany (n = 260) and examined whether different neonatal treatment and rates of disability affect HRQoL in adulthood.

METHOD

To analyse whether cohorts differed in adult HRQoL, linear regression analyses were performed for three HRQoL outcomes assessed with the Health Utilities Index 3 (HUI3), the London Handicap Scale (LHS), and the WHO Quality of Life instrument (WHOQOL-BREF). Stepwise hierarchical linear regression was used to test whether neonatal physical health and treatment, social environment, and intelligence (IQ) were related to VP/VLBW adults' HRQoL and cohort differences.

RESULTS

Dutch VP/VLBW adults reported a significantly higher HRQoL on all three general HRQoL measures than German VP/VLBW adults (HUI3: .86 vs .83, p = .036; LHS: .93 vs. .90, p = .018; WHOQOL-BREF: 82.8 vs. 78.3, p < .001). Main predictor of cohort differences in all three HRQoL measures was adult IQ (p < .001).

CONCLUSIONS

Lower HRQoL in German versus Dutch adults was related to more cognitive impairment in German adults. Due to different policies, German VP/VLBW infants received more intensive treatment that may have affected their cognitive development. Our findings stress the importance of examining effects of different neonatal treatment policies for VP/VLBW adults' life.

Reinforcement of the Brain's Rich-Club Architecture Following Early Neurodevelopmental Disruption Caused by Very Preterm Birth

The second half of pregnancy is a crucial period for the development of structural brain connectivity, and an abrupt interruption of the typical processes of development during this phase caused by the very preterm birth (<33 weeks of gestation) is likely to result in long-lasting consequences. We used structural and diffusion imaging data to reconstruct the brain structural connectome in very preterm-born adults. We assessed its rich-club organization and modularity as 2 characteristics reflecting the capacity to support global and local information exchange, respectively. Our results suggest that the establishment of global connectivity patterns is prioritized over peripheral connectivity following early neurodevelopmental disruption. The very preterm brain exhibited a stronger rich-club architecture than the control brain, despite possessing a relative paucity of white matter resources. Using a simulated lesion approach, we also investigated whether putative structural reorganization takes place in the very preterm brain in order to compensate for its anatomical constraints. We found that connections between the basal ganglia and (pre-) motor regions, as well as connections between subcortical regions, assumed an altered role in the structural connectivity of the very preterm brain, and that such alterations had functional implications for information flow, rule learning, and verbal IQ.

The case of late preterm birth: sliding forwards the critical window for cognitive outcome risk

Many survivors of preterm birth experience neurodevelopmental disabilities, such as cerebral palsy, visual and hearing problems. However, even in the absence of major neurological complications, premature babies show significant neuropsychological and behavioural deficits during childhood and beyond. While the clinical tools routinely used to assess neurocognitive development in those infants have been useful in detecting major clinical complications in early infancy, they have not been equally sensitive in identifying subtle cognitive impairments emerging during childhood. These methodological concerns become even more relevant when considering the case of late preterm children (born between 34 and 36 gestational weeks). Although these children have been traditionally considered as having similar risks for developmental problems as neonates born at term, a recent line of research has provided growing evidence that even late preterm children display altered structural and functional brain maturation, with potential life-long implications for neurocognitive functioning. A recent study by Heinonen put forward the hypothesis that environmental factors, in this case educational attainment, could moderate the association between late preterm birth (LPT) and neuropsychological impairments commonly associated with aging. In this paper we bring together clinical literature and recent neuroimaging evidence in order to provide two different but complementary approaches for a better understanding of the "nature-nurture" interplay underlying the lifespan neurocognitive development of preterm babies.