The role of neuroimaging in predicting neurodevelopmental outcomes of preterm neonates

Key roles of glial cells in the encephalopathy of prematurity

Across the globe, approximately one in 10 babies are born preterm, that is, before 37 weeks of a typical 40 weeks of gestation. Up to 50% of preterm born infants develop brain injury, encephalopathy of prematurity (EoP), that substantially increases their risk for developing lifelong defects in motor skills and domains of learning, memory, emotional regulation, and cognition. We are still severely limited in our abilities to prevent or predict preterm birth. No longer just the "support cells," we now clearly understand that during development glia are key for building a healthy brain. Glial dysfunction is a hallmark of EoP, notably, microgliosis, astrogliosis, and oligodendrocyte injury. Our knowledge of glial biology during development is exponentially expanding but hasn't developed sufficiently for development of effective neuroregenerative therapies. This review summarizes the current state of knowledge for the roles of glia in infants with EoP and its animal models, and a description of known glial-cell interactions in the context of EoP, such as the roles for border-associated macrophages. The field of perinatal medicine is relatively small but has worked passionately to improve our understanding of the etiology of EoP coupled with detailed mechanistic studies of pre-clinical and human cohorts. A primary finding from this review is that expanding our collaborations with computational biologists, working together to understand the complexity of glial subtypes, glial maturation, and the impacts of EoP in the short and long term will be key to the design of therapies that improve outcomes.

Divergent growth of the transient brain compartments in fetuses with nonsyndromic isolated clefts involving the primary and secondary palate

Cleft lip/palate is a common orofacial malformation that often leads to speech/language difficulties as well as developmental delays in affected children, despite surgical repair. Our understanding of brain development in these children is limited. This study aimed to analyze prenatal brain development in fetuses with cleft lip/palate and controls. We examined in utero MRIs of 30 controls and 42 cleft lip/palate fetal cases and measured regional brain volumes. Cleft lip/palate was categorized into groups A (cleft lip or alveolus) and B (any combination of clefts involving the primary and secondary palates). Using a repeated-measures regression model with relative brain hemisphere volumes (%), and after adjusting for multiple comparisons, we did not identify significant differences in regional brain growth between group A and controls. Group B clefts had significantly slower weekly cerebellar growth compared with controls. We also observed divergent brain growth in transient brain structures (cortical plate, subplate, ganglionic eminence) within group B clefts, depending on severity (unilateral or bilateral) and defect location (hemisphere ipsilateral or contralateral to the defect). Further research is needed to explore the association between regional fetal brain growth and cleft lip/palate severity, with the potential to inform early neurodevelopmental biomarkers and personalized diagnostics.

Fluid overload in newborns undergoing abdominal surgery: a retrospective study

BACKGROUND

Fluid management in newborns undergoing surgery can be challenging due to difficulties in accurately assessing volume status in context of high fluid needs perioperatively and postoperative third-space fluid loss. Fluid overload can be associated with an increase in neonatal morbidity and mortality.

OBJECTIVE

Our objective was to determine the burden of fluid overload and to evaluate their associations with adverse effects among infants undergoing abdominal surgery at a tertiary perinatal center.

METHODS

Patients from our Neonatal Intensive Care Unit who underwent abdominal surgery from January 2017 to June 2019 were included in this retrospective cohort study. Fluid balance was assessed based on the maximum percentage change in body weight at 3- and 7-postoperative days.

RESULTS

Sixty infants were included, with a median [interquartile range] gestational age (GA) of 29 [25-36] weeks and birth weight of 1240 [721-2871] grams. The median daily actual fluid intake was significantly higher than the prescribed fluid intake in the first 7 postoperative days (163 vs. 145 mL/kg, p < .01). The median maximum change of body weight by postoperative days 3 and 7 were 6% [3-13] and 11% [5-17], respectively. A 1% increase in weight within the first 3 postoperative days was associated with a 0.6-day increase for invasive ventilatory support (p = .012). The correlation was still significant after adjusting for GA (p = .033).

CONCLUSION

Fluid overload within the first 3 postoperative days was associated with an increase in ventilator support among infants. Careful attention to fluid management may affect the optimization of outcomes for newborns undergoing abdominal surgery.

Improving Methods of Diagnosis and Treatment of Posthemorrhagic Hydrocephalus in Young Children

BACKGROUND

One of the most severe perinatal lesions of the central nervous system is intraventricular hemorrhage, which often, especially in prematurely born babies with low gestational age and body weight, is complicated by posthemorrhagic hydrocephalus, which requires good early diagnosis and timely treatment. The purpose of the article is to improve the methods of diagnosis and treatment of posthemorrhagic hydrocephalus in young children.

METHODS

The study was conducted between 2009 and 2018 in the neurosurgical department of the City Children's Hospital No. 2 in Astana. Three groups of patients from birth to age six months were studied. During the investigation the following research methods were used: clinical and anamnestic, laboratory, instrumental, and methods of mathematical statistics. Statistical analysis was performed using the program Statistica for Windows 13.0 (StatSoft Inc. No. JPZ804I382130ARCN10-J). Patients of the main and control groups underwent various surgical interventions to relieve posthemorrhagic occlusive hydrocephalus.

RESULTS

It was found that the maximum number of complications develop in newborns with low gestational age and low body weight. Repeated lumbar or ventricular punctures in patients with posthemorrhagic hydrocephalus followed by external drainage are characterized by the greatest number of complications, among which infection and catheter occlusion prevail.

CONCLUSIONS

It has been established that the proposed algorithm for the diagnosis and treatment of patients with posthemorrhagic hydrocephalus can significantly reduce the number of complications, shorten the duration of hospital stay, reduce the percentage of long-term complications, and improve the quality of life.

Longitudinal neonatal brain development and socio-demographic correlates of infant outcomes following preterm birth

Preterm birth results in premature exposure of the brain to the extrauterine environment during a critical period of neurodevelopment. Consequently, infants born preterm are at a heightened risk of adverse behavioural outcomes in later life. We characterise longitudinal development of neonatal regional brain volume and functional connectivity in the first weeks following preterm birth, sociodemographic factors, and their respective relationships to psychomotor outcomes and psychopathology in toddlerhood. We study 121 infants born preterm who underwent magnetic resonance imaging shortly after birth, at term-equivalent age, or both. Longitudinal regional brain volume and functional connectivity were modelled as a function of psychopathology and psychomotor outcomes at 18 months. Better psychomotor functioning in toddlerhood was associated with greater relative right cerebellar volume and a more rapid decrease over time of sensorimotor degree centrality in the neonatal period. In contrast, increased 18-month psychopathology was associated with a more rapid decrease in relative regional subcortical volume. Furthermore, while socio-economic deprivation was related to both psychopathology and psychomotor outcomes, cognitively stimulating parenting predicted psychopathology only. Our study highlights the importance of longitudinal imaging to better predict toddler outcomes following preterm birth, as well as disparate environmental influences on separable facets of behavioural development in this population.

Detection of Global Brain Injury Using Point-of-Care Neonatal MRI Scanner

BACKGROUND

 Conventional magnetic resonance imaging (MRI) neuroimaging of infants is complicated by the need to transport infants outside the neonatal intensive care unit (NICU), often to distant areas of the hospital.

PRIMARY OBJECTIVE

 The main aim of this study was to evaluate and compare scoring of images from a novel 1T MRI, which enables neuroimaging within the NICU, with those from a conventional MRI.

SECONDARY OBJECTIVE

 The second aim of this study was to document improved expediency, and thereby greater patient safety, as reflected by decreased transport time.

MATERIALS AND METHODS

 Thirty premature infants (mean gestational age: 28.8 ± 2.1 weeks) were scanned consecutively on the novel 1T and 1.5T conventional scanners at term-equivalent age. Orthogonal T1- and T2-weighted images were acquired and reviewed. A global brain abnormality score (Kidokoro) was assigned independently to all images by two radiologists. Interrater agreement was evaluated using the kappa statistic and interscanner agreement was evaluated by Bland-Altman analysis. Transport time to and from both scanners was monitored and compared.

RESULTS

 Weighted kappas were 0.77 (standard error of measurement [SEM] 0.08; confidence interval [CI]: 0.62-0.92) and 0.86 (SEM: 0.07; CI: 0.73-1), for the 1T and 1.5T scanners, respectively, reflecting substantial interrater agreement. Bland-Altman analysis showed excellent agreement between the two scanners.Transport time was 8 ± 6 minutes for the 1T MRI versus 46 ± 21 minutes for the conventional MRI (p < 0.00001). No adverse events were recorded during transport. Standard transport times will vary from institution to institution.

CONCLUSIONS

 Kidokoro scores are similar when comparing images obtained from a 1T MRI with those of a conventional 1.5T MRI, reflecting comparable image quality. Transport time was significantly decreased using the 1T neonatal MRI.

1H-magnetic resonance spectroscopy and its role in predicting neurodevelopmental impairment in preterm neonates: A systematic review

To assess the diagnostic utility of proton (1H) magnetic resonance spectroscopy in early diagnosis of neurodevelopmental impairment in preterm newborns. Systematic review performed in compliance with the PRISMA statements. Eligible articles were searched in MEDLINE, Scopus, and ISI Web of Science databases using the following medical subject headings and terms: "magnetic resonance spectroscopy," "infant," and "newborn." Studies of any design published until 20 December 2021 and fulfilling the following criteria were selected: (1) studies including newborns with gestational age at birth <37 weeks which underwent at least one 1H-MRS scan within 52 weeks' postmenstrual age and neurodevelopmental assessment within 4 years of age; (2) studies in which preterm newborns with congenital infections, genetic disorders, and brain congenital anomalies were clearly excluded. Data regarding the relationship between metabolite ratios in basal ganglia, thalamus, and white matter, and neurodevelopment were analysed. The quality assessment of included studies was performed according to the criteria from the QUADAS-2. N-acetylaspartate (NAA)/choline (Cho) was the most studied metabolite ratio. Lower NAA/Cho ratio in basal ganglia and thalamus was associated with adverse motor, cognitive, and language outcomes, and worse global neurodevelopment. Lower NAA/Cho ratio in white matter was associated with cognitive impairment. However, some associations came from single studies or were discordant among studies. The quality of included studies was low. 1H-MRS could be a promising tool for early diagnosis of neurodevelopmental impairment. However, further studies of good quality are needed to define the relationship between metabolite ratios and neurodevelopment.

microRNA Biology on Brain Development and Neuroimaging Approach

Proper brain development requires the precise coordination and orchestration of various molecular and cellular processes and dysregulation of these processes can lead to neurological diseases. In the past decades, post-transcriptional regulation of gene expression has been shown to contribute to various aspects of brain development and function in the central nervous system. MicroRNAs (miRNAs), short non-coding RNAs, are emerging as crucial players in post-transcriptional gene regulation in a variety of tissues, such as the nervous system. In recent years, miRNAs have been implicated in multiple aspects of brain development, including neurogenesis, migration, axon and dendrite formation, and synaptogenesis. Moreover, altered expression and dysregulation of miRNAs have been linked to neurodevelopmental and psychiatric disorders. Magnetic resonance imaging (MRI) is a powerful imaging technology to obtain high-quality, detailed structural and functional information from the brains of human and animal models in a non-invasive manner. Because the spatial expression patterns of miRNAs in the brain, unlike those of DNA and RNA, remain largely unknown, a whole-brain imaging approach using MRI may be useful in revealing biological and pathological information about the brain affected by miRNAs. In this review, we highlight recent advancements in the research of miRNA-mediated modulation of neuronal processes that are important for brain development and their involvement in disease pathogenesis. Also, we overview each MRI technique, and its technological considerations, and discuss the applications of MRI techniques in miRNA research. This review aims to link miRNA biological study with MRI analytical technology and deepen our understanding of how miRNAs impact brain development and pathology of neurological diseases.

The paradox of Prader-Willi syndrome revisited: Making sense of the phenotype

Prader-Willi syndrome arises as a consequence of absent paternal copies of maternally imprinted genes at 15q11-13. Such gender-of-origin imprinted genes are expressed in the brain and also in mammalian placenta where paternally expressed imprinted genes drive foetal nutritional demand. We hypothesise that the PWS phenotype is the result of the genotype impacting two pathways: first, directly on brain development and secondly, on placental nutritional pathways that results in its down-regulation and relative foetal starvation. The early PWS phenotype establishes the basis for the later characteristic phenotype. Hyperphagia. and other phenotypic characteristics arise as a consequence of impaired hypothalamic development. Hypothalamic feeding pathways become set in a state indicative of starvation, with a high satiety threshold and a dysfunctional neurophysiological state due to incorrect representations of reward needs, based on inputs that indicate a false requirement for food. Our hypotheses, if confirmed, would lead to novel and effective interventions.

Structural and functional connectivity in premature neonates

Advances in neuroimaging have increasingly enabled researchers to investigate whether alterations in brain development commonly identified in preterm infants underlie their high risk of long-term neurodevelopmental impairment, including sensory, motor, cognitive, and psychiatric deficits. This review begins by examining the growing body of literature utilizing advanced magnetic resonance imaging (MRI) techniques to probe structural (via diffusion MRI) and functional (via resting state-functional MRI) connectivity development in the preterm brain during the neonatal period, both in the presence and absence of brain injury. It then details the recent work linking neonatal brain connectivity measures to neurodevelopmental and psychiatric outcomes in prematurely-born cohorts. Finally, building upon the recent substantive growth in the utilization of these neuroimaging modalities, it concludes by highlighting areas in which continued optimization of age-specific acquisition and analysis techniques for these data remains necessary, efforts fundamental to advancing the field toward establishing individual-level predictive capabilities in this high-risk population.

Deep Multimodal Learning From MRI and Clinical Data for Early Prediction of Neurodevelopmental Deficits in Very Preterm Infants

The prevalence of disabled survivors of prematurity has increased dramatically in the past 3 decades. These survivors, especially, very preterm infants (VPIs), born ≤ 32 weeks gestational age, are at high risk for neurodevelopmental impairments. Early and clinically effective personalized prediction of outcomes, which forms the basis for early treatment decisions, is urgently needed during the peak neuroplasticity window—the first couple of years after birth—for at-risk infants, when intervention is likely to be most effective. Advances in MRI enable the noninvasive visualization of infants' brains through acquired multimodal images, which are more informative than unimodal MRI data by providing complementary/supplementary depicting of brain tissue characteristics and pathology. Thus, analyzing quantitative multimodal MRI features affords unique opportunities to study early postnatal brain development and neurodevelopmental outcome prediction in VPIs. In this study, we investigated the predictive power of multimodal MRI data, including T2-weighted anatomical MRI, diffusion tensor imaging, resting-state functional MRI, and clinical data for the prediction of neurodevelopmental deficits. We hypothesize that integrating multimodal MRI and clinical data improves the prediction over using each individual data modality. Employing the aforementioned multimodal data, we proposed novel end-to-end deep multimodal models to predict neurodevelopmental (i.e., cognitive, language, and motor) deficits independently at 2 years corrected age. We found that the proposed models can predict cognitive, language, and motor deficits at 2 years corrected age with an accuracy of 88.4, 87.2, and 86.7%, respectively, significantly better than using individual data modalities. This current study can be considered as proof-of-concept. A larger study with external validation is important to validate our approach to further assess its clinical utility and overall generalizability.

Lack of Progression of Intraventricular Hemorrhage in Premature Infants: Implications for Head Ultrasound Screening

Very preterm infants are at risk for germinal matrix hemorrhage- intraventricular hemorrhage (GH-IVH). Severe GH-IVH may cause death or severe neurodevelopmental disability while mild GH-IVH is considered a static, non-progressive disease. This retrospective study aimed to determine if infants with no GH-IVH or mild GH-IVH on initial screening head ultrasound (HUS) advanced to severe GH-IVH. A total of 353 eligible infants with birth gestational age ≤32 0/7 weeks who received a HUS during hospitalization were identified. Of the 343 (97%) infants who had mild GH-IVH (grade II or less) on initial screening, only 4 (1.2%) progressed to severe (grade III or IV). Each of these infants required mechanical ventilation for at least 40 days. Therefore, premature infants who have no GH-IVH or mild GH-IVH on initial routine screening HUS without other risk factors may not require follow-up HUSs. Infants with prolonged mechanical ventilation may require further screening despite reassuring initial HUS findings.

Structural Changes in the Cortico-Ponto-Cerebellar Axis at Birth are Associated with Abnormal Neurological Outcomes in Childhood

White matter lesions in hypoxic-ischemic encephalopathy (HIE) are considered to be the important substrate of frequent neurological consequences in preterm infants. The aim of the study was to analyze volumes and tractographic parameters of the cortico-ponto-cerebellar axis to assess alterations in the periventricular fiber system and crossroads, corticopontine and corticospinal pathways and prospective transsynaptic changes of the cerebellum.Term infants (control), premature infants without (normotypic) and with perinatal HIE (HIE) underwent brain magnetic resonance imaging at term-equivalent age (TEA) and at 2 years. Cerebrum, cerebellum, brainstem divisions and ventrodorsal compartments volumetric analysis were performed, as well as fractional anisotropy (FA) and apparent diffusion coefficient (ADC) of corticopontine, corticospinal pathways and middle cerebellar peduncles. Amiel-Tison scale at TEA and the Hempel test at 2 years were assessed.Cerebellum, brainstem and its compartments volumes were decreased in normotypic and HIE groups at TEA, while at 2 years volumes were significantly reduced in the HIE group, accompanied by decreased volume and FA and increased ADC of corticopontine and corticospinal pathways. Negative association of the brainstem, cerebellum, mesencephalon, pons, corticopontine volumes and corticospinal pathway FA at TEA with the neurological score at 2 years. Cerebellum and pons volumes presented as potential prognostic indicators of neurological outcomes.Our findings agree that these pathways, as a part of the periventricular fiber system and crossroads, exhibit lesion-induced reaction and vulnerability in HIE. Structural differences between normotypic and HIE group at the 2 years suggest a different developmental structural plasticity.

Early diagnosis and treatment of infants with prenatal and perinatal risk factors for brain damage at the neurodevelopmental research unit in Mexico

Prenatal and perinatal risk factors for perinatal brain damage frequently produce brain injuries in preterm and term infants. The early diagnosis and treatment of these infants, in the period of higher brain plasticity, may prevent the neurological and cognitive sequels that accompany these lesions. The Neurodevelopmental Research Unit at the Institute of Neurobiology of the National Autonomous University of Mexico has taken this endeavor. A multidisciplinary approach is followed. Pediatric, neurologic and rehabilitation clinical studies, MRI, EEG, visual and auditory evoked responses, and Bayley II evaluations are carried out initially. Infants are followed up to 8 years, with periodic appointments for evaluation and treatment. Katona's neurohabilitation method is used for initial diagnosis and treatment. Selective visual and auditory attention are explored from 3 months of age. This method was created in the Unit and, if deficiencies are observed, the method also describes the treatment to avoid subsequent alterations of these processes. Deficiencies in the acquisition of language are evaluated from 4 months of age, implementing treatment through instructions to parents on how they should teach their children to speak. This method has also been developed in the Unit and is in its validation process. In the MRI, we pay special attention to subtle and diffuse patterns, due to the high frequency with which they appear in contemporary cohorts at a national and international level. More than 80% of these infants showed abnormal MRI findings that should be taken into consideration. The outcome of children at 8 years old showed that 78%, 76% and 78% of extremely preterm, very preterm and late preterm, respectively, had a normal neurodevelopment. In term infants, only 69% had a normal neurodevelopment; in this group, the majority of infants had very severe brain lesions. Conclusions: It is necessary to evaluate, at an early age, all newborns with prenatal and perinatal risk factors for brain damage. Special attention should be payed to all premature newborns and those newborns who have been discharged from the intensive care unit.

Neuroimaging at Term Equivalent Age: Is There Value for the Preterm Infant? A Narrative Summary

Advances in neuroimaging of the preterm infant have enhanced the ability to detect brain injury. This added information has been a blessing and a curse. Neuroimaging, particularly with magnetic resonance imaging, has provided greater insight into the patterns of injury and specific vulnerabilities. It has also provided a better understanding of the microscopic and functional impacts of subtle and significant injuries. While the ability to detect injury is important and irresistible, the evidence for how these injuries link to specific long-term outcomes is less clear. In addition, the impact on parents can be profound. This narrative summary will review the history and current state of brain imaging, focusing on magnetic resonance imaging in the preterm population and the current state of the evidence for how these patterns relate to long-term outcomes.

Early Diagnostics and Early Intervention in Neurodevelopmental Disorders-Age-Dependent Challenges and Opportunities

This review discusses early diagnostics and early intervention in developmental disorders in the light of brain development. The best instruments for early detection of cerebral palsy (CP) with or without intellectual disability are neonatal magnetic resonance imaging, general movements assessment at 2-4 months and from 2-4 months onwards, the Hammersmith Infant Neurological Examination and Standardized Infant NeuroDevelopmental Assessment. Early detection of autism spectrum disorders (ASD) is difficult; its first signs emerge at the end of the first year. Prediction with the Modified Checklist for Autism in Toddlers and Infant Toddler Checklist is possible to some extent and improves during the second year, especially in children at familial risk of ASD. Thus, prediction improves substantially when transient brain structures have been replaced by permanent circuitries. At around 3 months the cortical subplate has dissolved in primary motor and sensory cortices; around 12 months the cortical subplate in prefrontal and parieto-temporal cortices and cerebellar external granular layer have disappeared. This review stresses that families are pivotal in early intervention. It summarizes evidence on the effectiveness of early intervention in medically fragile neonates, infants at low to moderate risk, infants with or at high risk of CP and with or at high risk of ASD.

Diffusion-MRI-based regional cortical microstructure at birth for predicting neurodevelopmental outcomes of 2-year-olds

Cerebral cortical architecture at birth encodes regionally differential dendritic arborization and synaptic formation. It underlies behavioral emergence of 2-year-olds. Brain changes in 0-2 years are most dynamic across the lifespan. Effective prediction of future behavior with brain microstructure at birth will reveal structural basis of behavioral emergence in typical development and identify biomarkers for early detection and tailored intervention in atypical development. Here we aimed to evaluate the neonate whole-brain cortical microstructure quantified by diffusion MRI for predicting future behavior. We found that individual cognitive and language functions assessed at the age of 2 years were robustly predicted by neonate cortical microstructure using support vector regression. Remarkably, cortical regions contributing heavily to the prediction models exhibited distinctive functional selectivity for cognition and language. These findings highlight regional cortical microstructure at birth as a potential sensitive biomarker in predicting future neurodevelopmental outcomes and identifying individual risks of brain disorders.

Brain Development in Infants of Mothers With Gestational Diabetes Mellitus: A Diffusion Tensor Imaging Study

OBJECTIVE

The objective of this study was to investigate clinical neurocognitive performance and microstructural white matter (WM) alterations in infants of mothers with gestational diabetes mellitus (GDM) using diffusion tensor imaging.

MATERIALS AND METHODS

Infants (corrected gestational age, 33.42-36.00 weeks) of mothers with GDM (n = 31) and gestational age- and sex-matched unexposed controls (n = 31) accomplished 3-T diffusion tensor imaging scans and neurocognitive tests. Diffusion tensor imaging measures, mainly referring to fractional anisotropy (FA) values, were compared between 2 groups, and within-group analysis of correlation between FA values and neurocognitive testing outcomes in GDM-exposed infants was conducted subsequently.

RESULTS

Fractional anisotropy was significantly decreased in the splenium of corpus callosum, posterior limb of internal capsule, thalamus in infants of mothers with GDM when compared with controls (P < 0.05), reflecting microstructural WM abnormalities in the GDM group. Decreased FA was associated with worse neurocognitive performance in the exposed group (P < 0.05).

CONCLUSIONS

Individuals of mothers with GDM showed microstructural WM abnormalities in different brain regions, which were significantly related to worse neurocognitive performance. This might reveal that GDM directly insults the brain development of the offspring.

Routine Neuroimaging of the Preterm Brain

Neuroimaging of the preterm infant is a common assessment performed in the NICU. Timely and focused studies can be used for diagnostic, therapeutic, and prognostic information. However, significant variability exists among neonatal units as to which modalities are used and when imaging studies are obtained. Appropriate timing and selection of neuroimaging studies can help identify neonates with brain injury who may require therapeutic intervention or who may be at risk for neurodevelopmental impairment. This clinical report reviews the different modalities of imaging broadly available to the clinician. Evidence-based indications for each modality, optimal timing of examinations, and prognostic value are discussed.

White matter injury and neurodevelopmental disabilities: A cross-disease (dis)connection

White matter (WM) injury, once known primarily in preterm newborns, is emerging in its non-focal (diffused), non-necrotic form as a critical component of subtle brain injuries in many early-life diseases like prematurity, intrauterine growth restriction, congenital heart defects, and hypoxic-ischemic encephalopathy. While advances in medical techniques have reduced the number of severe outcomes, the incidence of tardive impairments in complex cognitive functions or psychopathology remains high, with lifelong detrimental effects. The importance of WM in coordinating neuronal assemblies firing and neural groups synchronizing within multiple frequency bands through myelination, even mild alterations in WM structure, may interfere with the cognitive performance that increasing social and learning demands would exploit tardively during children growth. This phenomenon may contribute to explaining longitudinally the high incidence of late-appearing impairments that affect children with a history of perinatal insults. Furthermore, WM abnormalities have been highlighted in several neuropsychiatric disorders, such as autism and schizophrenia. In this review, we gather and organize evidence on how diffused WM injuries contribute to neurodevelopmental disorders through different perinatal diseases and insults. An insight into a possible common, cross-disease, mechanism, neuroimaging and monitoring, biomarkers, and neuroprotective strategies will also be presented.

Neonatal Neuroimaging

Significant advances in the field of neonatal imaging has resulted in the generation of large complex data sets of relevant information for routine daily clinical practice, and basic and translational research. The evaluation of this data is a complex task for the neonatal imager who must distinguish normal and incidental findings from clinically significant abnormalities which are often adjunctive data points applicable to clinical evaluation and treatment. This review provides an overview of the imaging manifestations of disease processes commonly encountered in the neonatal brain. Since MRI is currently the highest yield technique for the diagnosis and characterization of the normal and abnormal brain, it is therefore the focus of the majority of this review. When applicable, discussion of some of the pertinent known pathophysiology and neuropathological aspects of disease processes are reviewed.

Specific cognitive deficits in preschool age correlated with qualitative and quantitative MRI parameters in prematurely born children

BACKGROUND

Cognitive deficits after perinatal brain lesion in preterm infants are among the most common neurodevelopmental disturbances. The relationship between structural changes on at term magnetic resonance imaging (MRI) and cognitive deficits in the preschool age should be a special focus due to timely intervention. The aim of this study was to correlate qualitative and quantitative MRI parameters of perinatal brain lesion in preterm children, on early neonatal MRI and follow up MRI, with general and specific cognitive functions in the preschool age.

METHODS

Twenty-one preterm infants with verified perinatal lesions based on clinical and ultrasound data underwent a brain MRI at term-equivalent age and a second MRI between 3 and 5 years of age. Qualitative and quantitative MRI analyses were done. All subjects underwent cognitive assessment (3-5 years) using Wechsler Preschool and Primary Scale of Intelligence (WPPSI-III) and Developmental Neuropsychological Assessment (NEPSY-II).

RESULTS

Results show that many structural changes on at term MRI and on follow up MRI in preterm born children moderately correlate with specific cognitive deficits in preschool age. At term equivalent MRI, white matter changes and cortical thickness correlate to general and specific cognitive functions in infants born preterm. By analyzing follow up MRI at preschool age, structural changes of different white matter segments, corpus callosum, cortical thickness and lobe volume correlate to some specific cognitive functions.

CONCLUSION

Besides general cognitive delay, specific cognitive deficits in preterm children should be targeted in research and intervention, optimally combined with MRI scanning, providing timely and early intervention of cognitive deficits after perinatal brain lesion. Our results, as well as previously published results, suggest the importance of detailed preschool neuropsychological assessment, prior to enrolment in the school system. Although preliminary, our results expand our understanding of the relationship between early brain developmental lesions and cognitive outcome following premature birth.

Conventional and Deep Learning Methods for Skull Stripping in Brain MRI

Skull stripping in brain magnetic resonance volume has recently been attracting attention due to an increased demand to develop an efficient, accurate, and general algorithm for diverse datasets of the brain. Accurate skull stripping is a critical step for neuroimaging diagnostic systems because neither the inclusion of non-brain tissues nor removal of brain parts can be corrected in subsequent steps, which results in unfixed error through subsequent analysis. The objective of this review article is to give a comprehensive overview of skull stripping approaches, including recent deep learning-based approaches. In this paper, the current methods of skull stripping have been divided into two distinct groups—conventional or classical approaches, and convolutional neural networks or deep learning approaches. The potentials of several methods are emphasized because they can be applied to standard clinical imaging protocols. Finally, current trends and future developments are addressed giving special attention to recent deep learning algorithms.

Quantitative MRI study of infant regional brain size following surgery for long-gap esophageal atresia requiring prolonged critical care

INTRODUCTION

Little is known regarding the impact of concurrent critical illness and thoracic noncardiac perioperative critical care on postnatal brain development. Previously, we reported smaller total brain volumes in both critically ill full-term and premature patients following complex perioperative critical care for long-gap esophageal atresia (LGEA). Our current report assessed trends in regional brain sizes during infancy, and probed for any group differences.

METHODS

Full-term (n = 13) and preterm (n = 13) patients without any previously known neurological concerns, and control infants (n = 16), underwent non-sedated 3 T MRI in infancy (<1 year old). T2-weighted images underwent semi-automated brain segmentation using Morphologically Adaptive Neonatal Tissue Segmentation (MANTiS). Regional tissue volumes of the forebrain, deep gray matter (DGM), cerebellum, and brainstem are presented as absolute (cm3) and normalized (% total brain volume (%TBV)) values. Group differences were assessed using a general linear model univariate analysis with corrected age at scan as a covariate.

RESULTS

Absolute volumes of regions analyzed increased with advancing age, paralleling total brain size, but were significantly smaller in both full-term and premature patients compared to controls. Normalized volumes (%TBV) of forebrain, DGM, and cerebellum were not different between subject groups analyzed. Normalized brainstem volumes showed group differences that warrant future studies to confirm the same finding.

DISCUSSION

Both full-term and premature critically ill infants undergoing life-saving surgery for LGEA are at risk of smaller total and regional brain sizes. Normalized volumes support globally delayed or diminished brain growth in patients. Future research should look into neurodevelopmental outcomes of infants born with LGEA.

Ex vivo fetal brain MRI: Recent advances, challenges, and future directions

During early development, the fetal brain undergoes dynamic morphological changes. These changes result from neurogenic events, such as neuronal proliferation, migration, axonal elongation, retraction, and myelination. The duration and intensity of these events vary across species. Comparative assessments of these neurogenic events give us insight into evolutionary changes and the complexity of human brain development. Recent advances in magnetic resonance imaging (MRI), especially ex vivo MRI, permit characterizing and comparing fetal brain development across species. Comparative ex vivo MRI studies support the detection of species-specific differences that occur during early brain development. In this review, we provide a comprehensive overview of ex vivo MRI studies that characterize early brain development in humans, monkeys, cats, as well as rats/mice. Finally, we discuss the current advantages and limitations of ex vivo fetal brain MRI.

Dysmaturation of Premature Brain: Importance, Cellular Mechanisms, and Potential Interventions

Prematurity, especially preterm birth (less than 32 weeks' gestation), is common and associated with high rates of both survival and neurodevelopmental disability, especially apparent in cognitive spheres. The neuropathological substrate of this disability is now recognized to be related to a variety of dysmaturational disturbances of the brain. These disturbances follow initial brain injury, particularly cerebral white matter injury, and involve many of the extraordinary array of developmental events active in cerebral white and gray matter structures during the premature period. This review delineates these developmental events and the dysmaturational disturbances that occur in premature infants. The cellular mechanisms involved in the genesis of the dysmaturation are emphasized, with particular focus on the preoligodendrocyte. A central role for the diffusely distributed activated microglia and reactive astrocytes in the dysmaturation is now apparent. As these dysmaturational cellular mechanisms appear to occur over a relatively long time window, interventions to prevent or ameliorate the dysmaturation, that is, neurorestorative interventions, seem possible. Such interventions include pharmacologic agents, especially erythropoietin, and particular attention has also been paid to such nutritional factors as quality and source of milk, breastfeeding, polyunsaturated fatty acids, iron, and zinc. Recent studies also suggest a potent role for interventions directed at various experiential factors in the neonatal period and infancy, i.e., provision of optimal auditory and visual exposures, minimization of pain and stress, and a variety of other means of environmental behavioral enrichment, in enhancing brain development.

Structural brain maturation differs between preterm and term piglets, whereas brain activity does not

AIM

The aim of the study was to investigate whether amplitude-integrated electroencephalography (aEEG) and cerebral magnetic resonance imaging (MRI) in preterm piglets would provide measures of cerebral functional, microstructural and anatomical maturation, which might reflect the signs of functional brain immaturity, documented in preterm piglets.

METHODS

During July-October 2013 at the NEOMUNE Centre, Copenhagen University, Denmark, 31 preterm (90% gestation) and 10 term piglets underwent aEEG on days 1, 2, 4 and 11, and MRI on day 25. Physical activity levels were recorded.

RESULTS

Preterm showed delayed neonatal arousal and physical activity, relative to term piglets. Preterm piglets had lower growth rates and brain volume than term piglets, but aEEG patterns were similar. MRI mean diffusivity was also similar, but fractional anisotropy (FA) was lower in preterm piglets (p < 0.001).

CONCLUSION

Functional brain maturation, as assessed by aEEG, was relatively advanced in preterm piglets. Conversely, the low FA in the preterm piglets suggests that the white matter microstructure remains less mature in preterm compared to term piglets at postnatal day 25. The results might be utilised to define whether and how preterm piglets may contribute to preclinical models for brain development in preterm infants.

Duration of Initial Empirical Antibiotic Therapy and Outcomes in Very Low Birth Weight Infants

: media-1vid110.1542/5984244681001PEDS-VA_2018-2286Video Abstract BACKGROUND: Overuse of antibiotics can facilitate antibiotic resistance and is associated with adverse neonatal outcomes. We studied the association between duration of antibiotic therapy and short-term outcomes of very low birth weight (VLBW) (<1500 g) infants without culture-proven sepsis.

METHODS

We included VLBW infants admitted to NICUs in the Canadian Neonatal Network between 2010-2016 who were exposed to antibiotics but did not have culture-proven sepsis in the first week. Antibiotic exposure was calculated as the number of days an infant received antibiotics in the first week of life. Composite primary outcome was defined as mortality or any major morbidity (severe neurologic injury, retinopathy of prematurity, necrotizing enterocolitis, chronic lung disease, or hospital-acquired infection).

RESULTS

Of the 14 207 included infants, 21% (n = 2950), 38% (n = 5401), and 41% (n = 5856) received 0, 1 to 3, and 4 to 7 days of antibiotics, respectively. Antibiotic exposure for 4 to 7 days was associated with higher odds of the composite outcome (adjusted odds ratio 1.24; 95% confidence interval [CI] 1.09-1.41). Each additional day of antibiotic use was associated with 4.7% (95% CI 2.6%-6.8%) increased odds of composite outcome and 7.3% (95% CI 3.3%-11.4%) increased odds in VLBW infants at low risk of early-onset sepsis (born via cesarean delivery, without labor and without chorioamnionitis).

CONCLUSIONS

Prolonged empirical antibiotic exposure within the first week after birth in VLBW infants is associated with increased odds of the composite outcome. This practice is a potential target for antimicrobial stewardship.

Exploring early human brain development with structural and physiological neuroimaging

Early brain development, from the embryonic period to infancy, is characterized by rapid structural and functional changes. These changes can be studied using structural and physiological neuroimaging methods. In order to optimally acquire and accurately interpret this data, concepts from adult neuroimaging cannot be directly transferred. Instead, one must have a basic understanding of fetal and neonatal structural and physiological brain development, and the important modulators of this process. Here, we first review the major developmental milestones of transient cerebral structures and structural connectivity (axonal connectivity) followed by a summary of the contributions from ex vivo and in vivo MRI. Next, we discuss the basic biology of neuronal circuitry development (synaptic connectivity, i.e. ensemble of direct chemical and electrical connections between neurons), physiology of neurovascular coupling, baseline metabolic needs of the fetus and the infant, and functional connectivity (defined as statistical dependence of low-frequency spontaneous fluctuations seen with functional magnetic resonance imaging (fMRI)). The complementary roles of magnetic resonance imaging (MRI), electroencephalography (EEG), magnetoencephalography (MEG), and near-infrared spectroscopy (NIRS) are discussed. We include a section on modulators of brain development where we focus on the placenta and emerging placental MRI approaches. In each section we discuss key technical limitations of the imaging modalities and some of the limitations arising due to the biology of the system. Although neuroimaging approaches have contributed significantly to our understanding of early brain development, there is much yet to be done and a dire need for technical innovations and scientific discoveries to realize the future potential of early fetal and infant interventions to avert long term disease.

A framework for multi-component analysis of diffusion MRI data over the neonatal period

We describe a framework for creating a time-resolved group average template of the developing brain using advanced multi-shell high angular resolution diffusion imaging data, for use in group voxel or fixel-wise analysis, atlas-building, and related applications. This relies on the recently proposed multi-shell multi-tissue constrained spherical deconvolution (MSMT-CSD) technique. We decompose the signal into one isotropic component and two anisotropic components, with response functions estimated from cerebrospinal fluid and white matter in the youngest and oldest participant groups, respectively. We build an orientationally-resolved template of those tissue components from data acquired from 113 babies between 33 and 44 weeks postmenstrual age, imaged as part of the Developing Human Connectome Project. These data were split into weekly groups, and registered to the corresponding group average templates using a previously-proposed non-linear diffeomorphic registration framework, designed to align orientation density functions (ODF). This framework was extended to allow the use of the multiple contrasts provided by the multi-tissue decomposition, and shown to provide superior alignment. Finally, the weekly templates were registered to the same common template to facilitate investigations into the evolution of the different components as a function of age. The resulting multi-tissue atlas provides insights into brain development and accompanying changes in microstructure, and forms the basis for future longitudinal investigations into healthy and pathological white matter maturation.

Resting-state functional MRI studies on infant brains: A decade of gap-filling efforts

Resting-state functional MRI (rs-fMRI) is one of the most prevalent brain functional imaging modalities. Previous rs-fMRI studies have mainly focused on adults and elderly subjects. Recently, infant rs-fMRI studies have become an area of active research. After a decade of gap filling studies, many facets of the brain functional development from early infancy to toddler has been uncovered. However, infant rs-fMRI is still in its infancy. The image analysis tools for neonates and young infants can be quite different from those for adults. From data analysis to result interpretation, more questions and issues have been raised, and new hypotheses have been formed. With the anticipated availability of unprecedented high-resolution rs-fMRI and dedicated analysis pipelines from the Baby Connectome Project (BCP), it is important now to revisit previous findings and hypotheses, discuss and comment existing issues and problems, and make a "to-do-list" for the future studies. This review article aims to comprehensively review a decade of the findings, unveiling hidden jewels of the fields of developmental neuroscience and neuroimage computing. Emphases will be given to early infancy, particularly the first few years of life. In this review, an end-to-end summary, from infant rs-fMRI experimental design to data processing, and from the development of individual functional systems to large-scale brain functional networks, is provided. A comprehensive summary of the rs-fMRI findings in developmental patterns is highlighted. Furthermore, an extensive summary of the neurodevelopmental disorders and the effects of other hazardous factors is provided. Finally, future research trends focusing on emerging dynamic functional connectivity and state-of-the-art functional connectome analysis are summarized. In next decade, early infant rs-fMRI and developmental connectome study could be one of the shining research topics.

Impact of delivered tidal volume on the occurrence of intraventricular haemorrhage in preterm infants during positive pressure ventilation in the delivery room

BACKGROUND AND OBJECTIVES

Delivery of inadvertent high tidal volume (V_T) during positive pressure ventilation (PPV) in the delivery room is common. High V_T delivery during PPV has been associated with haemodynamic brain injury in animal models. We examined if V_T delivery during PPV at birth is associated with brain injury in preterm infants <29 weeks' gestation.

METHODS

A flow-sensor was placed between the mask and the ventilation device. V_T values were compared with recently described reference ranges for V_T in spontaneously breathing preterm infants at birth. Infants were divided into two groups: V_T<6  mL/kg or V_T>6 mL/kg (normal and high V_T, respectively). Brain injury (eg, intraventricular haemorrhage (IVH)) was assessed using routine ultrasound imaging within the first days after birth.

RESULTS

A total of 165 preterm infants were included, 124 (75%) had high V_T and 41 (25%) normal V_T. The mean (SD) gestational age and birth weight in high and normal V_T group was similar, 26 (2) and 26 (1) weeks, 858 (251) g and 915 (250) g, respectively. IVH in the high V_T group was diagnosed in 63 (51%) infants compared with 5 (13%) infants in the normal V_T group (P=0.008).Severe IVH (grade III or IV) developed in 33/124 (27%) infants in the high V_T group and 2/41 (6%) in the normal V_T group (P=0.01).

CONCLUSIONS

High V_T delivery during mask PPV at birth was associated with brain injury. Strategies to limit V_T delivery during mask PPV should be used to prevent high V_T delivery.

Aberrant structural and functional connectivity and neurodevelopmental impairment in preterm children

Background

Despite advances in antenatal and neonatal care, preterm birth remains a leading cause of neurological disabilities in children. Infants born prematurely, particularly those delivered at the earliest gestational ages, commonly demonstrate increased rates of impairment across multiple neurodevelopmental domains. Indeed, the current literature establishes that preterm birth is a leading risk factor for cerebral palsy, is associated with executive function deficits, increases risk for impaired receptive and expressive language skills, and is linked with higher rates of co-occurring attention deficit hyperactivity disorder, anxiety, and autism spectrum disorders. These same infants also demonstrate elevated rates of aberrant cerebral structural and functional connectivity, with persistent changes evident across advanced magnetic resonance imaging modalities as early as the neonatal period. Emerging findings from cross-sectional and longitudinal investigations increasingly suggest that aberrant connectivity within key functional networks and white matter tracts may underlie the neurodevelopmental impairments common in this population.

Main body

This review begins by highlighting the elevated rates of neurodevelopmental disorders across domains in this clinical population, describes the patterns of aberrant structural and functional connectivity common in prematurely-born infants and children, and then reviews the increasingly established body of literature delineating the relationship between these brain abnormalities and adverse neurodevelopmental outcomes. We also detail important, typically understudied, clinical, and social variables that may influence these relationships among preterm children, including heritability and psychosocial risks.

Conclusion

Future work in this domain should continue to leverage longitudinal evaluations of preterm infants which include both neuroimaging and detailed serial neurodevelopmental assessments to further characterize relationships between imaging measures and impairment, information necessary for advancing our understanding of modifiable risk factors underlying these disorders and best practices for improving neurodevelopmental trajectories in this high-risk clinical population.

Symptomatic seizures in preterm newborns: a review on clinical features and prognosis

Neonatal seizures are the most common neurological event in newborns, showing higher prevalence in preterm than in full-term infants. In the majority of cases they represent acute symptomatic phenomena, the main etiologies being intraventricular haemorrhage, hypoxic-ischemic encephalopathy, central nervous system infections and transient metabolic derangements.Current definition of neonatal seizures requires detection of paroxysmal EEG-changes, and in preterm newborns the incidence of electrographic-only seizures seems to be particularly high, further stressing the crucial role of electroencephalogram monitoring in this population. Imaging work-up includes an integration of serial cranial ultrasound and brain magnetic resonance at term-equivalent age. Unfavourable outcomes following seizures in preterm infants include death, neurodevelopmental impairment, epilepsy, cerebral palsy, hearing and visual impairment. As experimental evidence suggests a detrimental role of seizures per se in determining subsequent outcome, they should be promptly treated with the aim to reduce seizure burden and long-term disabilities. However, neonatal seizures show low response to conventional anticonvulsant drugs, and this is even more evident in preterm newborns, due to intrinsic developmental factors. As a consequence, as literature does not provide any specific guidelines, due to the lack of robust evidence, off-label medications are often administered in clinical practice.

Neuroimaging for Neurodevelopmental Prognostication in High-Risk Neonates

Predicting neurodevelopmental outcomes in high-risk neonates remains challenging despite advances in neonatal care. Early and accurate characterization of infants at risk for neurodevelopmental delays is necessary to best identify those who may benefit from existing early interventions and novel therapies that become available. Although neuroimaging is a promising biomarker in the prediction of neurodevelopmental outcomes in high-risk infants, it requires additional resources and expertise. Despite many advances in neonatal neuroimaging, there remain limitations in relating early neuroimaging findings with long-term outcomes; further studies are necessary to determine the optimal protocols to best identify high-risk patients and improve neurodevelopmental outcome prediction.

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.

Body length and occipitofrontal circumference may be good indicators of neurodevelopment in very low birthweight infants - secondary publication

AIM

The aim of this study was to predict the neurological prognosis of very low birthweight (VLBW) infants. We examined the relationship between nutritional status, brain volume measured by magnetic resonance imaging (MRI) and anthropometric measurements of VLBW infants at term-equivalent age (TEA).

METHODS

We evaluated 27 VLBW infants, born at Showa University Hospital in Japan between April 2012 and August 2013, who underwent brain MRI at TEA. Based on their clinical data, we analysed their protein and energy intake.

RESULTS

Median values for the 27 VLBW infants were as follows: gestational age, 29.7 weeks; birthweight 1117 g; protein intake 2.7 g/kg/day and energy intake 97.9 kcal/kg/day. At TEA, the standard deviation scores (SDSs) of body weight, body length and the occipitofrontal circumference (OFC) were -0.8, -1.4 and 0.7, respectively. Multiple regression analysis revealed that the SDSs of body length and the OFC at TEA were significant determinants of white matter volume, but that the SDS of body weight at TEA was not.

CONCLUSION

Our findings suggest that the SDSs of body length and the OFC at TEA may be better indicators than body weight for predicting the development of the central nervous system in VLBW infants receiving nutritional management.

Alterations in Anatomical Covariance in the Prematurely Born

Preterm (PT) birth results in long-term alterations in functional and structural connectivity, but the related changes in anatomical covariance are just beginning to be explored. To test the hypothesis that PT birth alters patterns of anatomical covariance, we investigated brain volumes of 25 PTs and 22 terms at young adulthood using magnetic resonance imaging. Using regional volumetrics, seed-based analyses, and whole brain graphs, we show that PT birth is associated with reduced volume in bilateral temporal and inferior frontal lobes, left caudate, left fusiform, and posterior cingulate for prematurely born subjects at young adulthood. Seed-based analyses demonstrate altered patterns of anatomical covariance for PTs compared with terms. PTs exhibit reduced covariance with R Brodmann area (BA) 47, Broca's area, and L BA 21, Wernicke's area, and white matter volume in the left prefrontal lobe, but increased covariance with R BA 47 and left cerebellum. Graph theory analyses demonstrate that measures of network complexity are significantly less robust in PTs compared with term controls. Volumes in regions showing group differences are significantly correlated with phonological awareness, the fundamental basis for reading acquisition, for the PTs. These data suggest both long-lasting and clinically significant alterations in the covariance in the PTs at young adulthood.

Using Functional Magnetic Resonance Imaging to Detect Preserved Function in a Preterm Infant with Brain Injury

We studied developmental plasticity using functional magnetic resonance imaging (fMRI) in a preterm infant with brain injury on structural MRI. fMRI showed preserved brain function and subsequent neurodevelopment was within the normal range. Multimodal neuroimaging including fMRI can improve understanding of neural plasticity after preterm birth and brain injury.

Clinical neuroimaging in the preterm infant: Diagnosis and prognosis

Perinatal care advances emerging over the past twenty years have helped to diminish the mortality and severe neurological morbidity of extremely and very preterm neonates (e.g., cystic Periventricular Leukomalacia [c-PVL] and Germinal Matrix Hemorrhage - Intraventricular Hemorrhage [GMH-IVH grade 3-4/4]; 22 to < 32 weeks of gestational age, GA). However, motor and/or cognitive disabilities associated with mild-to-moderate white and gray matter injury are frequently present in this population (e.g., non-cystic Periventricular Leukomalacia [non-cystic PVL], neuronal-axonal injury and GMH-IVH grade 1-2/4). Brain research studies using magnetic resonance imaging (MRI) report that 50% to 80% of extremely and very preterm neonates have diffuse white matter abnormalities (WMA) which correspond to only the minimum grade of severity. Nevertheless, mild-to-moderate diffuse WMA has also been associated with significant affectations of motor and cognitive activities. Due to increased neonatal survival and the intrinsic characteristics of diffuse WMA, there is a growing need to study the brain of the premature infant using non-invasive neuroimaging techniques sensitive to microscopic and/or diffuse lesions. This emerging need has led the scientific community to try to bridge the gap between concepts or ideas from different methodologies and approaches; for instance, neuropathology, neuroimaging and clinical findings. This is evident from the combination of intense pre-clinical and clinicopathologic research along with neonatal neurology and quantitative neuroimaging research. In the following review, we explore literature relating the most frequently observed neuropathological patterns with the recent neuroimaging findings in preterm newborns and infants with perinatal brain injury. Specifically, we focus our discussions on the use of neuroimaging to aid diagnosis, measure morphometric brain damage, and track long-term neurodevelopmental outcomes.

Neurodevelopmental Abnormalities and Congenital Heart Disease: Insights Into Altered Brain Maturation

In the past 2 decades, it has become evident that individuals born with congenital heart disease (CHD) are at risk of developing life-long neurological deficits. Multifactorial risk factors contributing to neurodevelopmental abnormalities associated with CHD have been identified; however, the underlying causes remain largely unknown, and efforts to address this issue have only recently begun. There has been a dramatic shift in focus from newly acquired brain injuries associated with corrective and palliative heart surgery to antenatal and preoperative factors governing altered brain maturation in CHD. In this review, we describe key time windows of development during which the immature brain is vulnerable to injury. Special emphasis is placed on the dynamic nature of cellular events and how CHD may adversely impact the cellular units and networks necessary for proper cognitive and motor function. In addition, we describe current gaps in knowledge and offer perspectives about what can be done to improve our understanding of neurological deficits in CHD. Ultimately, a multidisciplinary approach will be essential to prevent or improve adverse neurodevelopmental outcomes in individuals surviving CHD.

Event-Related Potentials Reflect Deficits in Lexical Access: The N200 in Prematurely Born School-Aged Children

OBJECTIVES

Children born preterm have a high prevalence of neurocognitive deficits early in life. We examined whether the neural correlates of lexical access are atypical in 9-year-old children born preterm, and whether the findings of acoustic mapping correlate with language- and attention-related skills.

PATIENTS AND METHODS

The subjects were fourteen 9-year-old children born preterm and 14 full-term, typically developing controls. Two auditory event-related potential (ERP) components, the N200 and the N400, were used to assess discrimination response and word recognition. A set of behavioral tests (naming ability, auditory attention, phonological processing, pseudoword repetition, and comprehension of instructions) was performed, and the results were compared with the amplitudes, latencies, and scalp distribution of the ERP results.

RESULTS

In prematurely born children, neurophysiological deficits were associated with difficulties in auditory discrimination. The N200 amplitude correlated significantly with auditory attention and pseudoword repetition. The scalp distribution of both the N200 and the N400 was broader in children born preterm than in the controls. Low scores in the neuropsychological tasks referred to difficulties in auditory processing and memory.

CONCLUSIONS

Children born preterm have difficulties in lexical access together with memory- and attention-related processes, which may have a longstanding impact on their school outcomes and academic skills.

Cerebellar Microstructural Organization is Altered by Complications of Premature Birth: A Case-Control Study

OBJECTIVES

To compare regional cerebellar microstructure, as measured by diffusion tensor imaging (DTI), between preterm infants at term-equivalent age and healthy term-born control neonates, and to explore associations between DTI findings and clinical risk factors.

STUDY DESIGN

In this case-control study, DTI studies were performed in 73 premature infants born ≤32 weeks and ≤1500 g birth weight and 73 full-term-born controls from healthy pregnancies. Using a region of interest approach, fractional anisotropy (FA) and mean diffusivity (MD) were extracted in 7 cerebellar regions including the anterior vermis, the right/left superior cerebellar peduncles, the middle cerebellar peduncle, and the dentate nuclei. To validate further our DTI measurements, we measured FA and MD in the genu of the corpus callosum and splenium. FA and MD were compared between groups using analyses of multiple linear regression models.

RESULTS

Preterm infants at term-equivalent age presented with higher FA in the dentate nuclei (<.001) and middle cerebellar peduncle (.028), and lower MD in the vermis (.023) compared with controls. Conversely, preterm infants showed reduced FA and increased MD in both the genu of the corpus callosum and splenium (P < .001). Independent risk factors associated with altered FA and MD in the cerebellum included low Apgar score, supratentorial injury, compromised cardiorespiratory function, and surgery for necrotizing enterocolitis and patent ductus arteriosus.

CONCLUSIONS

This DTI study provides evidence that complications of premature birth are associated with altered cerebellar microstructural organization when compared with term-born control infants.

Impact of Early Nutritional Intake on Preterm Brain: A Magnetic Resonance Imaging Study

OBJECTIVES

To investigate the association between early nutritional intake and brain development assessed by magnetic resonance imaging (MRI).

STUDY DESIGN

A cohort of neonates born at ≤30 weeks gestational age underwent MRI at term equivalent age. Brain maturation and injury were assessed using the Kidokoro score. Two groups were defined by severity of the scores. The associations between macronutrients intake during the first 2 weeks of life, clinical factors, and imaging scores were analyzed using logistic regression.

RESULTS

MRI scores from group 1 patients (n = 27) were normal to mildly abnormal (0-5). Group 2 (n = 15) had more abnormal scores (6-12). The median gestational ages (IQR) were 27.4 (1.9) weeks in group 1 and 27.0 (2.9) weeks in group 2, with birth weights of 900 (318) g (group 1) and 844 (293) g (group 2). In group 2, energy, lipid, and carbohydrate intake were significantly lower than in group 1. Group 2 also showed higher rates of sepsis and clinical risk scores than group 1. After adjustments in bivariate models, higher energy and lipid intake remained significantly associated with improved scores on MRI. This association was stronger for the gray matter component of the score.

CONCLUSIONS

Higher energy and lipid intake during the first 2 weeks after birth was associated with a lower incidence of brain lesions and dysmaturation at term equivalent age in preterm neonates.

Incidental findings on routine brain MRI scans in preterm infants

OBJECTIVE

Many neonatal intensive care units (NICUs) have adopted the practice of performing routine brain MRI in very low birth weight (VLBW) infants at term-equivalent age in order to better evaluate prematurity-related acquired lesions. A number of unexpected brain abnormalities of potential clinical significance can be visualised on routine scans as well. The aim of our study was to describe these incidental findings (IFs) in a VLBW population and to assess their clinical significance.

STUDY DESIGN

We retrospectively reviewed a series of brain MRI scans performed in VLBW infants consecutively admitted to our NICU between November 2011 and November 2014. IFs on brain MRI, which were not detected by cranial ultrasound nor suspected clinically, were registered. Clinical significance of IF was assessed in terms of need of further diagnostic or therapeutic interventions.

RESULTS

IFs were detected in 28 out of 276 VLBW infants (10.1%). In total, 21 cases (7.6%) required an intervention, which was only diagnostic in 16 cases, and both diagnostic and therapeutic in 5 cases. In the remaining seven cases (2.5%), no further action was considered necessary.

CONCLUSIONS

This study suggests that IFs on brain MRI of VLBW infants are not rare. In our population, most of them required a diagnostic or therapeutic intervention. The need and appropriateness of routine MRI scanning in VLBW at term-equivalent age are still subject of debate, and we believe our data can contribute meaningfully to this discussion.

Brain Lesions among Orally Fed and Gastrostomy-Fed Dysphagic Preterm Infants: Can Routine Qualitative or Volumetric Quantitative Magnetic Resonance Imaging Predict Feeding Outcomes?

INTRODUCTION

The usefulness of qualitative or quantitative volumetric magnetic resonance imaging (MRI) in early detection of brain structural changes and prediction of adverse outcomes in neonatal illnesses warrants further investigation. Our aim was to correlate certain brain injuries and the brain volume of feeding-related cortical and subcortical regions with feeding method at discharge among preterm dysphagic infants.

MATERIALS AND METHODS

Using a retrospective observational study design, we examined MRI data among 43 (22 male; born at 31.5 ± 0.8 week gestation) infants who went home on oral feeding or gastrostomy feeding (G-tube). MRI scans were segmented, and volumes of brainstem, cerebellum, cerebrum, basal ganglia, thalamus, and vermis were quantified, and correlations were made with discharge feeding outcomes. Chi-squared tests were used to evaluate MRI findings vs. feeding outcomes. ANCOVA was performed on the regression model to measure the association of maturity and brain volume between groups.

RESULTS

Out of 43 infants, 44% were oral-fed and 56% were G-tube fed at hospital discharge (but not at time of the study). There was no relationship between qualitative brain lesions and feeding outcomes. Volumetric analysis revealed that cerebellum was greater (p < 0.05) in G-tube fed infants, whereas cerebrum volume was greater (p < 0.05) in oral-fed infants. Other brain regions did not show volumetric differences between groups.

CONCLUSION

This study concludes that neither qualitative nor quantitative volumetric MRI findings correlate with feeding outcomes. Understanding the complexity of swallowing and feeding difficulties in infants warrants a comprehensive and in-depth functional neurological assessment.

Clinical impact of term-equivalent magnetic resonance imaging in extremely low-birth-weight infants at a regional NICU

OBJECTIVE

To evaluate the clinical impact of routine term-equivalent magnetic resonance imaging (TE-MRI) for extremely low-birth-weight infants at a regional neonatal intensive care unit.

STUDY DESIGN

This is a single-center retrospective study evaluating preterm survivors who underwent TE-MRI. MRI abnormalities were compared between infants with and without cranial ultrasonography (CUS) abnormalities. Cost analysis comparing imaging modalities was also performed.

RESULTS

TE-MRI use increased from 17% in 2006 to 76% in 2010. MRI detected new findings in nearly half of infants, whether or not they had known ultrasound abnormalities. MRI detected more cerebellar (18% vs 6%, P=0.04) and moderate white matter injury (12% vs 7%, P<0.001), and altered simulated neurological prognosis across developmental domains. The cost of TE-MRI was $1600, which was comparable to serial CUSs.

CONCLUSION

TE-MRI detects new abnormalities and impacts developmental prognosis in the extremely low birth weight, which supports its use despite the added financial cost.