PPREMO: a prospective cohort study of preterm infant brain structure and function to predict neurodevelopmental outcome

Diagnostic accuracy of neonatal structural MRI scores to predict 6-year motor outcomes of children born very preterm

AIMS

This study aimed to (1) evaluate associations between Early and Term structural MRI (sMRI) brain abnormality scores and adverse motor outcomes at 6-years corrected age (CA), (2) determine their diagnostic accuracy in predicting adverse motor outcomes and cerebral palsy (CP) at 6-years CA.

METHODS

Infants born < 31-weeks gestational age (GA) returning for 6-year follow-up were included. Early and Term sMRI were scored using a validated method, deriving white matter, cortical grey matter, deep grey matter, cerebellar and global brain abnormality scores (GBAS). At 6-years CA, Movement Assessment Battery for Children-2nd Edition (MABC-2) was administered. Linear regression assessed associations between Early and Term GBAS/subscale scores and 6-year MABC-2 total score. For diagnostic accuracy, sMRI scores were categorised as none/mild vs moderate/severe, MABC-2 cut-off ≤ 5th percentile, and CP as present/absent.

RESULTS

Infants had Early MRI (n = 123) at mean PMA 32.5-weeks (median GA 28.4-weeks; mean birthweight 1101 g) and n = 114 had Term MRI (Mean PMA 40.8-weeks). Nine had CP and n = 116 had MABC-2 scores. Early (B: -1.92; p ≤ 0.001) and Term (B: -1.67; p ≤ 0.01) GBAS were negatively associated with MABC-2 scores. Both Early and Term GBAS had high specificity (Sp) and low sensitivity (Se) in predicting MABC-2 ≤ 5th percentile (Early: Se 36 %, Sp 82 %; Term: Se 28 %, Sp 93 %) and predicted CP with high Se and Sp (Early: Se 78 %, Sp 78 %; Term: Se 75 %, Sp 89 %).

CONCLUSION

High Sp of Early and Term MRI predicting an outcome on MABC-2 may help accurately identify infants unlikely to develop motor impairments at 6-years CA.

Rehabilitation Intervention Is Associated With Improved Neurodevelopment and Modulation of Inflammatory Molecules in Children With Cerebral Palsy

AIM

To evaluate the effects of systematic rehabilitation on both the neuropsychomotor development, and on the peripheral response from immunological and neuroplastic mediators in children with cerebral palsy.

METHODS

This is a prospective cohort study with 90 children with cerebral palsy at 18 months of age. Sixty children received rehabilitation for 6 months, and they were compared to 30 children that were placed in the waiting list. Peripheral biomarkers and neuropsychomotor parameters were compared between the Rehab vs the Nonrehab groups at baseline and at 6 months.

RESULTS

Results showed higher Bayley III scores in the Rehab group, with significant differences in inflammatory and neurotrophic biomarkers between groups. Rehabilitation was associated to decreased levels of IL-12p70, IL-6, IL-1β, CXCL8 IL-8, and CXCL9/MIG and increased levels of BDNF and GDNF. Nonrehab children had stable immune molecule levels but decreased BDNF levels over time.

CONCLUSION

Rehabilitation improved neurodevelopment parameters and modulated levels of inflammatory (↓) and neurotrophic (↑) biomarkers.

Sensitivity and specificity of the Neonatal Visual Assessment to predict motor and cognitive outcomes in infants born very preterm

BACKGROUND

Very preterm infants are at increased risk of neurodevelopmental impairments. The Neonatal Visual Assessment (NVA) assesses visual function and outcomes and has been used to assess early neurodevelopmental outcomes. This study aimed to compare NVA results of very preterm and term-born infants and to calculate the sensitivity and specificity of the NVA at term equivalent age (TEA) and three months corrected age (CA) to predict motor and cognitive outcomes at 12 months CA in very preterm infants.

METHODS

This prospective observational cohort study recruited infants born before 31 weeks gestation and a healthy term-born control group. The NVA was assessed at TEA and three months CA, and neurodevelopmental outcomes (Bayley Scales of Infant and Toddler Development, Third Edition; Neurosensory Motor Developmental Assessment; Alberta Infant Motor Scale) were performed at 12 months CA. The sensitivity and specificity of the NVA to predict outcomes were calculated based on a previously published optimality score.

RESULTS

248 preterm (54 % male) and 46 term-born infants (48 % male) were analysed. The mean NVA scores of preterm and term-born infants were significantly different at TEA (preterm 3.1±2.1; term-born 1.2±1.7, p < 0.001). The NVA had moderate sensitivity (59-78 %) and low specificity (25-27 %) at TEA, and low sensitivity (21-28 %) and high specificity (86-87 %) at three months CA for the prediction of preterm infants' outcomes at 12 months CA.

CONCLUSION

The NVA at TEA and three months CA was not a strong predictor of motor and cognitive impairments in this contemporary cohort of very preterm infants.

Impact of Early- and High-Dose Caffeine on the Cerebellum Development in Newborn Rats

INTRODUCTION

Preterm newborns struggle with maintaining an adequate respiratory pattern; early caffeine administration is suggested to stimulate respiration and reduce bronchopulmonary dysplasia, however, its consequences on the immature cerebellum remains unknown. This study aimed to assess the impact of early caffeine administration, at standard and high doses, accompanied by supplemental oxygen on cerebellar development in an experimental model.

METHODS

Five groups of Wistar pups were formed (n = 8 offspring/group): (a) negative control: no intervention; (b) placebo: pups remaining from birth until the 7th day of life (DOL) exposed to fractional inspired oxygen (FiO2) 45%, resembling preterm infant condition and as a placebo, 0.2 mL oral 5% dextrose, from the first DOL until the 14th DOL; (c) caffeine group: oral caffeine, 1st DOL 20 mg/kg, and from 2nd to 14th DOL, 5 mg/kg (standard dose); (d) caffeine at the standard dose, plus O2: during the first 7 DOLs (FiO2: 45%); (e) caffeine: 40 mg/kg in the first DOL, 10 mg/kg the next 14 DOLs, plus O2 in the first 7 DOLs (FiO2: 45%). Subjects were sacrificed on their 15th DOL; measurements were taken from the cerebellum, specifically the external granular layer (EGL) and molecular layer (ML), with quantification of cell migration.

RESULTS

Caffeine administration in pups resulted in a delay in cerebellum development based on persistent transitional EGL cells; this finding was exacerbated in groups exposed to caffeine plus O2, as evident from the thicker EGL. The negative control group showed near-complete cell migration with a thicker ML and a significantly smaller EGL.

CONCLUSIONS

Early caffeine administration in newborn rats disrupts cerebellar cortex cell processes and connectivity pathways, with exacerbated effects in groups receiving caffeine plus O2.

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

AIM

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

METHOD

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

RESULTS

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

INTERPRETATION

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

Motor Development Comparison between Preterm and Full-Term Infants Using Alberta Infant Motor Scale

The Alberta Infant Motor Scale (AIMS) was developed to evaluate the motor development of infants up to 18 months of age. We studied 252 infants in three groups (105 healthy preterm infants (HPI), 50 preterm infants with brain injury (PIBI), and 97 healthy full-term infants (HFI) under 18 months, corrected age (CoA)) using AIMS. No significant differences were found among HPI, PIBI, and HFI in infants less than 3 months old, yet significant differences were noted in positional scores (p < 0.05) and total scores for those four to six months of age and seven to nine months of age. A significant difference was also found in standing items for infants over 10 months (p < 0.05). After four months, there was a difference in motor development between preterm (with and without brain injury) and full-term infants. In particular, there was a significant difference in motor development between HPI and HFI and between PIBI and HFI at four to nine months, when motor skills developed explosively (p < 0.05). After four months, motor developmental delays (10th ≥) were observed in HPI and PIBI at rates of 26% and 45.8%, respectively. Midline supine development, a representative indicator of early motor development, was slower even in healthy preterm infants than in full-term infants. AIMS has a good resolution to discriminate preterm infants who are showing insufficient motor development from 4 months to 9 months.

Early brain morphometrics from neonatal MRI predict motor and cognitive outcomes at 2-years corrected age in very preterm infants

Infants born very preterm face a range of neurodevelopmental challenges in cognitive, language, behavioural and/or motor domains. Early accurate identification of those at risk of adverse neurodevelopmental outcomes, through clinical assessment and Magnetic Resonance Imaging (MRI), enables prognostication of outcomes and the initiation of targeted early interventions. This study utilises a prospective cohort of 181 infants born <31 weeks gestation, who had 3T MRIs acquired at 29-35 weeks postmenstrual age and a comprehensive neurodevelopmental evaluation at 2 years corrected age (CA). Cognitive, language and motor outcomes were assessed using the Bayley Scales of Infant and Toddler Development - Third Edition and functional motor outcomes using the Neuro-sensory Motor Developmental Assessment. By leveraging advanced structural MRI pre-processing steps to standardise the data, and the state-of-the-art developing Human Connectome Pipeline, early MRI biomarkers of neurodevelopmental outcomes were identified. Using Least Absolute Shrinkage and Selection Operator (LASSO) regression, significant associations between brain structure on early MRIs with 2-year outcomes were obtained (r = 0.51 and 0.48 for motor and cognitive outcomes respectively) on an independent 25% of the data. Additionally, important brain biomarkers from early MRIs were identified, including cortical grey matter volumes, as well as cortical thickness and sulcal depth across the entire cortex. Adverse outcome on the Bayley-III motor and cognitive composite scores were accurately predicted, with an Area Under the Curve of 0.86 for both scores. These associations between 2-year outcomes and patient prognosis and early neonatal MRI measures demonstrate the utility of imaging prior to term equivalent age for providing earlier commencement of targeted interventions for infants born preterm.

Maternal sevoflurane exposure induces neurotoxicity in offspring rats via the CB1R/CDK5/p-tau pathway

Sevoflurane is widely used for maternal anesthesia during pregnancy. Sevoflurane exposure of rats at mid-gestation can cause abnormal development of the central nervous system in their offspring. Sevoflurane is known to increase the expression of cannabinoid 1 receptor (CB1R) in the hippocampus. However, the effect of cannabinoid 1 receptor on fetal and offspring rats after maternal anesthesia is still unclear. At gestational day 14, pregnant rats were subjected to 2-h exposure to 3.5% sevoflurane or air. Rats underwent intraperitoneal injection with saline or rimonabant (1 mg/kg) 30 min prior to sevoflurane or air exposure. cannabinoid 1 receptor, cyclin-dependent kinase 5 (CDK5), p35, p25, tau, and p-tau expression in fetal brains was measured at 6, 12, and 24 h post-sevoflurane/air exposure. Neurobehavioral and Morris water maze tests were performed postnatal days 3-33. The expression of cannabinoid 1 receptor/cyclin-dependent kinase 5/p-tau and histopathological staining of brain tissues in offspring rats was observed. We found that a single exposure to sevoflurane upregulated the activity of cyclin-dependent kinase 5 and the level of p-tau via cannabinoid 1 receptor. This was accompanied by the diminished number of neurons and dendritic spines in hippocampal CA1 regions. Finally, these effects induced lower scores and platform crossing times in behavioral tests. The present study suggests that a single exposure to 3.5% sevoflurane of rats at mid-gestation impairs neurobehavioral abilities and cognitive memory in offspring. cannabinoid 1 receptor is a possible target for the amelioration of postnatal neurobehavioral ability and cognitive memory impairments induced by maternal anesthesia.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

CLINICAL TRIAL REGISTRATION

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

IMPACT

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

Multimodal magnetic resonance neuroimaging measures characteristic of early cART-treated pediatric HIV: A feature selection approach

Children with perinatally acquired HIV (CPHIV) have poor cognitive outcomes despite early combination antiretroviral therapy (cART). While CPHIV-related brain alterations can be investigated separately using proton magnetic resonance spectroscopy (1 H-MRS), structural magnetic resonance imaging (sMRI), diffusion tensor imaging (DTI), and functional MRI (fMRI), a set of multimodal MRI measures characteristic of children on cART has not been previously identified. We used the embedded feature selection of a logistic elastic-net (EN) regularization to select neuroimaging measures that distinguish CPHIV from controls and measured their classification performance via the area under the receiver operating characteristic curve (AUC) using repeated cross validation. We also wished to establish whether combining MRI modalities improved the models. In single modality analysis, sMRI volumes performed best followed by DTI, whereas individual EN models on spectroscopic, gyrification, and cortical thickness measures showed no class discrimination capability. Adding DTI and 1 H-MRS in basal measures to sMRI volumes produced the highest classification performancevalidation accuracy = 85 % AUC = 0.80 . The best multimodal MRI set consisted of 22 DTI and sMRI volume features, which included reduced volumes of the bilateral globus pallidus and amygdala, as well as increased mean diffusivity (MD) and radial diffusivity (RD) in the right corticospinal tract in cART-treated CPHIV. Consistent with previous studies of CPHIV, select subcortical volumes obtained from sMRI provide reasonable discrimination between CPHIV and controls. This may give insight into neuroimaging measures that are relevant in understanding the effects of HIV on the brain, thereby providing a starting point for evaluating their link with cognitive performance in CPHIV.

Protecting the brain of the micropreemie

Advances in perinatal care have seen substantial improvements in survival without disability for extremely preterm infants. Protecting the developing brain and reducing neurodevelopmental sequelae of extremely preterm birth are strategic priorities for both research and clinical care. A number of evidence-based interventions exist for neuroprotection in micropreemies, inclusive of prevention of preterm birth and multiple births with implantation of only one embryo during in vitro fertilisation, as well as antenatal care to optimize fetal wellbeing, strategies for supporting neonatal transition, and neuroprotective developmental care. Avoidance of complications that trigger ischemia and inflammation is vital for minimizing brain dysmaturation and injury, particularly of the white matter. Neurodevelopmental surveillance, early diagnosis of cerebral palsy and early intervention are essential for optimizing long-term outcomes and quality of life. Research priorities include further evaluation of putative neuroprotective agents, and investigation of common neonatal interventions in trials adequately powered to assess neurodevelopmental outcome.

Early Motor Repertoire of Very Preterm Infants and Relationships with 2-Year Neurodevelopment

The Motor Optimality Score, revised (MOS-R) is an extension of the Prechtl General Movements Assessment. This study aims to determine the relationship between MOS-R and 2-year neurodevelopmental outcomes in a cohort of 169 infants born very preterm (<31 weeks’ gestational age), and to examine the predictive validity of the MOS-R at 3−4 months’ corrected age (CA) above perinatal variables associated with poor outcomes, including Prechtl fidgety movements. Development at 2 years’ CA was assessed using Bayley Scales of Infant and Toddler Development, Third edition (Bayley-III) (motor/cognitive impairment: Bayley-III ≤ 85) and Neurological, Sensory, Motor, Developmental Assessment (NSMDA) (neurosensory motor impairment: NSMDA ≥ 12). Cerebral palsy (CP) was classified at 2 years as definite or clinical. The MOS-R was related to 2-year outcomes: Bayley-III motor (BMOS-R = 1.24 95% confidence interval (0.78, 1.70)), cognitive (BMOS-R = 0.91 (0.48, 1.35)), NSMDA scores (BMOS-R = −0.34 (−0.42, −0.25)), definite CP (odds ratio [OR] 0.67 (0.53, 0.86)), clinical CP (OR 0.74 (0.66, 0.83)) for each 1-point increase in MOS-R. MOS-R ≤ 23 predicted motor (sensitivity 78% (60−91%); specificity 63% (54−72%)) and neurosensory motor impairment (sensitivity 86% (64−97%); specificity 59% (51−68%)). The MOS-R is strongly related to CP and motor and cognitive delay at 2 years and is a good predictor of motor and neurosensory motor impairment.

Reliability Study of the Items of the Alberta Infant Motor Scale (AIMS) Using Kappa Analysis

Purpose: We evaluated the interrater and intrarater reliabilities of the Korean version of the Alberta Infant Motor Scale (K-AIMS). Methods: For the interrater reliability test, six raters participated in the K-AIMS evaluation using video clips of 70 infants (aged between 0 and 18 months). One rater participated in an intrarater reliability test. Among 70 infants, 46 were born preterm and 24 were born full term. A total of 58 AIMS items were evaluated for supine, prone, sitting, and standing positions. A reliability analysis was conducted using ICC and Fleiss’ kappa. Results: The highest Fleiss’ kappa was found for the 4–7 months group for sitting (K = 0.701–1.000) and standing (K = 0.721–1.000), while the lowest K was the 3 months or under group for standing (K = 0.153–1.000). We found higher Fleiss’ kappa statistics when all infants were evaluated without grouping for the three positions (K = 0.727–1.000), except standing (K = 0.192–1.000), for the interrater analysis. Conclusion: Our results demonstrate the good reliability for the Korean version of the AIMS for Korean infants (preterm and full term).

Early clinical and MRI biomarkers of cognitive and motor outcomes in very preterm born infants

BACKGROUND

This study aimed to identify which MRI and clinical assessments, alone or in combination, from (i) early (32 weeks postmenstrual age, PMA), (ii) term equivalent age (TEA) and (iii) 3 months corrected age (CA) are associated with motor or cognitive outcomes at 2 years CA in infants born <31 weeks gestation.

METHODS

Prospective cohort study of 98 infants who underwent early and TEA MRI (n = 59 males; median birth gestational age 28 + 5 weeks). Hammersmith Neonatal Neurological Examination (HNNE), NICU Neonatal Neurobehavioural Scale and General Movements Assessment (GMs) were performed early and at TEA. Premie-Neuro was performed early and GMs, Test of Infant Motor Performance and visual assessment were performed at TEA and 3 months CA. Neurodevelopmental outcomes were determined using Bayley Scales of Infant and Toddler Development 3rd edition.

RESULTS

The best combined motor outcome model included 3-month GMs (β = -11.41; 95% CI = -17.34, -5.49), TEA MRI deep grey matter score (β = -6.23; 95% CI = -9.47, -2.99) and early HNNE reflexes (β = 3.51; 95% CI = 0.86, 6.16). Combined cognitive model included 3-month GMs (β = -10.01; 95% CI = -15.90, -4.12) and TEA HNNE score (β = 1.33; 95% CI = 0.57, 2.08).

CONCLUSION

Early neonatal neurological assessment improves associations with motor outcomes when combined with term MRI and 3-month GMs. Term neurological assessment combined with 3-month GMs improves associations with cognitive outcomes.

IMPACT

We present associations between 32- and 40-week MRI, comprehensive clinical assessments and later 2-year motor and cognitive outcomes for children born <31 weeks gestation. MRI and clinical assessment of motor, neurological and neurobehavioural function earlier than term equivalent age in very preterm infants is safe and becoming more available in clinical settings. Most of these children are discharged from hospital before term age and so completing assessments prior to discharge can assist with follow up. MRI and neurological assessment prior to term equivalent age while the child is still in hospital can provide earlier identification of children at highest risk of adverse outcomes and guide follow-up screening and intervention services.

Automating Quantitative Measures of an Established Conventional MRI Scoring System for Preterm-Born Infants Scanned between 29 and 47 Weeks' Postmenstrual Age

BACKGROUND AND PURPOSE

Conventional MR imaging scoring is a valuable tool for risk stratification and prognostication of outcomes, but manual scoring is time-consuming, operator-dependent, and requires high-level expertise. This study aimed to automate the regional measurements of an established brain MR imaging scoring system for preterm neonates scanned between 29 and 47 weeks' postmenstrual age.

MATERIALS AND METHODS

This study used T2WI from the longitudinal Prediction of PREterm Motor Outcomes cohort study and the developing Human Connectome Project. Measures of biparietal width, interhemispheric distance, callosal thickness, transcerebellar diameter, lateral ventricular diameter, and deep gray matter area were extracted manually (Prediction of PREterm Motor Outcomes study only) and automatically. Scans with poor quality, failure of automated analysis, or severe pathology were excluded. Agreement, reliability, and associations between manual and automated measures were assessed and compared against statistics for manual measures. Associations between measures with postmenstrual age, gestational age at birth, and birth weight were examined (Pearson correlation) in both cohorts.

RESULTS

A total of 652 MRIs (86%) were suitable for analysis. Automated measures showed good-to-excellent agreement and good reliability with manual measures, except for interhemispheric distance at early MR imaging (scanned between 29 and 35 weeks, postmenstrual age; in line with poor manual reliability) and callosal thickness measures. All measures were positively associated with postmenstrual age (r = 0.11-0.94; R² = 0.01-0.89). Negative and positive associations were found with gestational age at birth (r = -0.26-0.71; R² = 0.05-0.52) and birth weight (r = -0.25-0.75; R² = 0.06-0.56). Automated measures were successfully extracted for 80%-99% of suitable scans.

CONCLUSIONS

Measures of brain injury and impaired brain growth can be automatically extracted from neonatal MR imaging, which could assist with clinical reporting.

Multi-Omics Analysis on Neurodevelopment in Preterm Neonates: A Protocol Paper

BACKGROUND

The gut microbiome is an important determinant of health and disease in preterm infants.

OBJECTIVES

The objective of this paper is to share our current protocol for other neonatal intensive care units to potentially expand their existing protocols aiming to characterize the relationship between the intestinal microbiome and health outcomes in preterm infants.

METHODS

This prospective, longitudinal study planned to recruit 160 preterm infants born <32 weeks' gestational age or weighing <1,500 grams and admitted to one of two-level III/IV neonatal intensive care units. During the neonatal intensive care unit period, the primary measures included events of early life pain/stress, gut microbiome, host genetic variations, and neurobehavioral assessment. During follow-up visits, gut microbiome, pain sensitivity, and medical, growth, and developmental outcomes at 4-, 8-12-, and 18-24-month corrected age (CA) were measured.

DISCUSSION

As of February 14, 2020, 214 preterm infants have been recruited. We hypothesize that infants who experience greater levels of pain/stress will have altered gut microbiome, including potential adverse outcomes such as necrotizing enterocolitis (NEC) and host genetic variations, feeding intolerance, and/or neurodevelopmental impairments. These will differ from the intestinal microbiome of preterm infants that do not develop these adverse outcomes. To test this hypothesis, we will determine how alterations in the intestinal microbiome affect the risk of developing NEC, feeding intolerance, and neurodevelopmental impairments in preterm infants. In addition, we will examine the interaction between the intestinal microbiome and host genetics in the regulation of intestinal health and neurodevelopmental outcomes.

Prediction of childhood brain outcomes in infants born preterm using neonatal MRI and concurrent clinical biomarkers (PREBO-6): study protocol for a prospective cohort study

INTRODUCTION

Infants born very preterm are at risk of adverse neurodevelopmental outcomes, including cognitive deficits, motor impairments and cerebral palsy. Earlier identification enables targeted early interventions to be implemented with the aim of improving outcomes.

METHODS AND ANALYSIS

Protocol for 6-year follow-up of two cohorts of infants born <31 weeks gestational age (PPREMO: Prediction of Preterm Motor Outcomes; PREBO: Prediction of Preterm Brain Outcomes) and a small term-born reference sample in Brisbane, Australia. Both preterm cohorts underwent very early MRI and concurrent clinical assessment at 32 and 40 weeks postmenstrual age (PMA) and were followed up at 3, 12 and 24 months corrected age (CA). This study will perform MRI and electroencephalography (EEG). Primary outcomes include the Movement Assessment Battery for Children second edition and Full-Scale IQ score from the Wechsler Intelligence Scale for Children fifth edition (WISC-V). Secondary outcomes include the Gross Motor Function Classification System for children with cerebral palsy; executive function (Behavior Rating Inventory of Executive Function second edition, WISC-V Digit Span and Picture Span, Wisconsin Card Sorting Test 64 Card Version); attention (Test of Everyday Attention for Children second edition); language (Clinical Evaluation of Language Fundamentals fifth edition), academic achievement (Woodcock Johnson IV Tests of Achievement); mental health and quality of life (Development and Well-Being Assessment, Autism Spectrum Quotient-10 Items Child version and Child Health Utility-9D).

AIMS

Examine the ability of early neonatal MRI, EEG and concurrent clinical measures at 32 weeks PMA to predict motor, cognitive, language, academic achievement and mental health outcomes at 6 years CA.Determine if early brain abnormalities persist and are evident on brain MRI at 6 years CA and the relationship to EEG and concurrent motor, cognitive, language, academic achievement and mental health outcomes.

ETHICS AND DISSEMINATION

Ethical approval has been obtained from Human Research Ethics Committees at Children's Health Queensland (HREC/19/QCHQ/49800) and The University of Queensland (2019000426). Study findings will be presented at national and international conferences and published in peer-reviewed journals.

TRIAL REGISTRATION NUMBER

ACTRN12619000155190p. WEB ADDRESS OF TRIAL: http://www.anzctr.org.au/Trial/Registration/TrialReview.aspx?ACTRN=12619000155190p.

Predicting motor outcome in preterm infants from very early brain diffusion MRI using a deep learning convolutional neural network (CNN) model

BACKGROUND AND AIMS

Preterm birth imposes a high risk for developing neuromotor delay. Earlier prediction of adverse outcome in preterm infants is crucial for referral to earlier intervention. This study aimed to predict abnormal motor outcome at 2 years from early brain diffusion magnetic resonance imaging (MRI) acquired between 29 and 35 weeks postmenstrual age (PMA) using a deep learning convolutional neural network (CNN) model.

METHODS

Seventy-seven very preterm infants (born <31 weeks gestational age (GA)) in a prospective longitudinal cohort underwent diffusion MR imaging (3T Siemens Trio; 64 directions, b ​= ​2000 ​s/mm²). Motor outcome at 2 years corrected age (CA) was measured by Neuro-Sensory Motor Developmental Assessment (NSMDA). Scores were dichotomised into normal (functional score: 0, normal; n ​= ​48) and abnormal scores (functional score: 1-5, mild-profound; n ​= ​29). MRIs were pre-processed to reduce artefacts, upsampled to 1.25 ​mm isotropic resolution and maps of fractional anisotropy (FA) were estimated. Patches extracted from each image were used as inputs to train a CNN, wherein each image patch predicted either normal or abnormal outcome. In a postprocessing step, an image was classified as predicting abnormal outcome if at least 27% (determined by a grid search to maximise the model performance) of its patches predicted abnormal outcome. Otherwise, it was considered as normal. Ten-fold cross-validation was used to estimate performance. Finally, heatmaps of model predictions for patches in abnormal scans were generated to explore the locations associated with abnormal outcome.

RESULTS

For the identification of infants with abnormal motor outcome based on the FA data from early MRI, we achieved mean sensitivity 70% (standard deviation SD 19%), mean specificity 74% (SD 39%), mean AUC (area under the receiver operating characteristic curve) 72% (SD 14%), mean F1 score of 68% (SD 13%) and mean accuracy 73% (SD 19%) on an unseen test data set. Patch-based prediction heatmaps showed that the patches around the motor cortex and somatosensory regions were most frequently identified by the model with high precision (74%) as a location associated with abnormal outcome. Part of the cerebellum, and occipital and frontal lobes were also highly associated with abnormal NSMDA/motor outcome.

DISCUSSION/CONCLUSION

This study established the potential of an early brain MRI-based deep learning CNN model to identify preterm infants at risk of a later motor impairment and to identify brain regions predictive of adverse outcome. Results suggest that predictions can be made from FA maps of diffusion MRIs well before term equivalent age (TEA) without any prior knowledge of which MRI features to extract and associated feature extraction steps. This method, therefore, is suitable for any case of brain condition/abnormality. Future studies should be conducted on a larger cohort to re-validate the robustness and effectiveness of these models.

Validation and Reliability of the Test of Infant Motor Performance for Brazilian Infants

Aim: To investigate the validity and reliability of the Portuguese version of the Test of Infant Motor Performance (TIMP) for Brazilian infants.Methods: The study was conducted with 20 health professionals and 655 Brazilian infants (between 34 weeks of Post-Menstrual Age and 17 weeks Corrected Age).Results: (1) Content validity: High concordance among the experts, for language clarity and pertinence, were found (ICC from.74 to .100; AC1 from .87 to 1.00); (2) Inter-rater, intra-rater, and test-retest reliability: Strong inter (α from .65 to .99) and intra (α from .97 to .99) raters agreement, and high test-retest reliability (r = 1.00; ICC = 1.00); (3) Internal consistency: Excellent internal consistency (α from .71 to .98); (4) Discriminant validity: Significant power to identify groups at-risk for delays (p < .0001); (5) Predictive validity: Capability to predict motor delay (r .55 to .89) was found; and, (6) Concurrent validity: Significant (p < .05) and low correlations at the first months (τ .21 to .24) and weak to moderate correlations at 3 and 4 month-old (τ .42 and .44, respectively) were observed between the TIMP and Alberta Infant Motor Scale.Conclusions: The results provide evidence of validity and reliability of the Portuguese version of the TIMP for Brazilian infants.

Newborns and preterm infants at term equivalent age: A semi-quantitative assessment of cerebral maturity

BACKGROUND AND PURPOSE

Currently available MRI scoring systems of cerebral maturation in term and preterm infant at term equivalent age do not include the changes of transient fetal compartments that persist to term age. We studied the visibility and the pattern of these structures in healthy term newborns compared to preterm infants at term equivalent age in order to investigate if they can be included in a new MRI score system. We hypothesized that transient fetal compartments are different in both groups, and that these differences can be characterized using the clinical T2-weighted MRIs.

MATERIALS AND METHODS

Using 3T MRI T2-weighted brain sequences of 21 full-term and 41 preterm infants (< 32 weeks), scanned at term equivalent age, 3 raters independently scored the maturation level of 3 transient fetal compartments: the periventricular crossroads, von Monakow segments of the white matter, and the subplate compartment. These 3 new items were included in a scoring system along with validated parameters of brain maturation (germinal matrix, bands of migration, subarachnoid space and quality of gyrification). A cumulative maturity score was calculated separately for both groups of newborns by adding together each item. More mature were the brain structures, higher was the cumulative maturity score.

RESULTS

Cumulative maturity score distinguished full-term from preterm infants (mean score 41/60 ± 1.4 versus 37/60 ± 2.5 points, p < 0.001), with an increase of 0.5 points for each supplemental gestational week at birth (r = 0.5, 95% CI 0.5 - 0.85). While a majority of transient fetal compartments were less mature in preterm group at term equivalent age, von Monakow segments of the white matter and subplate compartment presented a more advanced maturational stage in the preterm group compared to the term group. No subject had all scored items in the most mature state. Except a slight intra-rater agreement for von Monakow segment II, inter- and intra-rater agreements were moderate to excellent indicating the potential of the developed scoring system in routine clinical practice.

CONCLUSION

Brain transient fetal structures can be assessed on regular T2-weighted MRI in newborns. Their appearance differs between term and preterm babies. However our results suggest a more complex situation, with both delayed and accelerated maturation pattern in preterm infants. It remains to be determined if these differences could be biomarkers of the future neurodevelopment of preterm infants.

Predictive Value of Cranial Ultrasound for Neurodevelopmental Outcomes of Very Preterm Infants with Brain Injury

Background:

Compared with full-term infants, very preterm infants are more vulnerable to injury and long-term disability and are at high risk of death. The predictive value of ultrasound and imaging on the neurodevelopment is one of the hot topics. This study aimed to investigate the relationship between cranial ultrasound (cUS) variables and neurodevelopmental outcomes of very preterm infants.

Methods:

Totally 129 very preterm infants (gestational age ≤28 weeks) in neonatal intensive care unit of Hunan Children's Hospital between January 2012 and November 2014 were included in this retrospective study. Serial cUS (weekly before discharge and monthly after discharge) was performed on the infants until 6 months or older. Magnetic resonance imaging (MRI) was performed on the infants at approximately the term-equivalent age. The mental developmental index (MDI) and psychomotor developmental index (PDI) were followed up until the infants were 24 months or older. The relationship between brain injury and MDI/PDI scores was analyzed.

Results:

The consistency rate between cUS and MRI was 88%. At the first cUS, germinal matrix hemorrhage (GMH) Grades 3 and 4, hospitalization duration, and weight are significantly correlated with MDI/PDI and prognosis (MDI: odds ratio [OR] = 8.415, 0.982, and 0.042, P = 0.016, 0.000, and 0.004; PDI: OR = 7.149, 0.978, and 0.012, P = 0.025, 0.000, and 0.000, respectively). At the last cUS, gestational age, extensive cystic periventricular leukomalacia (c-PVL), and moderate and severe hydrocephaly are significantly correlated with MDI (OR = 0.292, 60.220, and 170.375, P = 0.004, 0.003, and 0.000, respectively). Extensive c-PVL and moderate and severe hydrocephaly are significantly correlated with PDI (OR = 76.861 and 116.746, P = 0.003 and 0.000, respectively).

Conclusions:

Very premature infants with GMH Grades 3 and 4, short hospitalization duration, and low weight have low survival rates and poorly developed brain nerves. Cerebral palsy can result from severe cerebral hemorrhage, moderate and severe hydrocephaly, and extensive c-PVL. The sustained, inhomogeneous echogenicity of white matter may suggest subtle brain injury.

Relationship between very early brain structure and neuromotor, neurological and neurobehavioral function in infants born <31 weeks gestational age

AIM

This study aimed to examine associations between structural MRI and concurrent motor, neurological and neurobehavioral measures at 30-32 weeks postmenstrual age (PMA; 'Early'), and at term equivalent age ('Term').

METHOD

In this prospective cohort study, infants underwent Early MRI (n = 119; 73 male; median 32 weeks 1 day PMA) and Term MRI (n = 102; 61 male; median 40 weeks 4 days PMA) at 3 T. Structural images were scored generating white matter (WM), cortical gray matter, deep gray matter, cerebellar and global brain abnormality scores. Clinical measures were General Movements Assessment (GMs), Hammersmith Neonatal Neurological Examination (HNNE) and NICU Neonatal Neurobehavioral Scale (NNNS). The Premie-Neuro was administered Early and the Test of Infant Motor Performance (TIMP) and a visual assessment at Term.

RESULTS

Early MRI cerebellar scores were strongly associated with neurological components of HNNE (reflexes), NNNS (Hypertonicity), the Premie-Neuro neurological subscale (regression coefficient β = -0.06; 95% confidence interval CI = -0.09, -0.04; p < .001) and cramped-synchronized GMs (β = 1.10; 95%CI = 0.57, 1.63; p < .001). Term MRI WM and global scores were strongly associated with the TIMP (WM β = -1.02; 95%CI = -1.67, -0.36; p = .002; global β = -1.59; 95%CI = -2.62, -0.56; p = .001).

INTERPRETATION

Brain structure on Early and Term MRI was associated with concurrent motor, neurological and neurobehavioral function in very preterm infants.

Fixel-based analysis reveals alterations is brain microstructure and macrostructure of preterm-born infants at term equivalent age

Preterm birth causes significant disruption in ongoing brain development, frequently resulting in adverse neurodevelopmental outcomes. Brain imaging using diffusion MRI may provide valuable insight into microstructural properties of the developing brain. The aim of this study was to establish whether the recently introduced fixel-based analysis method, with its associated measures of fibre density (FD), fibre bundle cross-section (FC), and fibre density and bundle cross-section (FDC), is suitable for the investigation of the preterm infant brain at term equivalent age. High-angular resolution diffusion weighted images (HARDI) of 55 preterm-born infants and 20 term-born infants, scanned around term-equivalent age, were included in this study (3 T, 64 directions, b = 2000 s/mm²). Postmenstrual age at the time of MRI, and intracranial volume (FC and FDC only), were identified as confounding variables. Gestational age at birth was correlated with all fixel measures in the splenium of the corpus callosum. Compared to term-born infants, preterm infants showed reduced FD, FC, and FDC in a number of regions, including the corpus callosum, anterior commissure, cortico-spinal tract, optic radiations, and cingulum. Preterm infants with minimal macroscopic brain abnormality showed more extensive reductions than preterm infants without any macroscopic brain abnormality; however, little differences were observed between preterm infants with no and with minimal brain abnormality. FC showed significant reductions in preterm versus term infants outside regions identified with FD and FDC, highlighting the complementary role of these measures. Fixel-based analysis identified both microstructural and macrostructural abnormalities in preterm born infants, providing a more complete picture of early brain development than previous diffusion tensor imaging (DTI) based approaches.

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Gestational age at birth associated with measurements in corpus callosum splenium.

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Preterms without macroscopic brain abnormality show differences to term infants.

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No differences between preterms with minimal versus without abnormality detected.

Biobehavioral Responses of Preterm Infants to Conventional and Swaddled Tub Baths: A Randomized Crossover Trial

Bathing is a routine care procedure that exposes preterm infants to prolonged handling, which could cause stress and potentially disrupt infants' biobehavioral responses. The aim of this double-blind randomized crossover trial was to compare the preterm infant's body temperature, heart rate (HR), peripheral capillary oxygen saturation (SpO2), salivary cortisol levels, and sleep-wake states during and after swaddled and conventional tub baths. Forty-three infants born at 32 to 36 weeks postmenstrual age, weighing 2225 g or less, were enrolled in the study. Infants were videotaped before and after each type of baths. The time interval between baths ranged from 24 to 72 hours to allow a washout period. Physiological, hormonal, and behavioral responses were collected at baseline and during recovery from baths. No significant differences in the mean body temperature, HR, SpO2, salivary cortisol levels, and sleep-wake states between the bath types were observed in the baseline or recovery responses during the first 20 minutes after bath. Regardless of bath type, salivary cortisol levels showed a nonstatistical significant increase.

Implementation of Early Diagnosis and Intervention Guidelines for Cerebral Palsy in a High-Risk Infant Follow-Up Clinic

BACKGROUND

Cerebral palsy is the most common physical disability in childhood, and is mostly diagnosed after age 2 years. Delays in diagnosis can have negative long-term consequences for children and parents. New guidelines for early cerebral palsy diagnosis and intervention were recently published, after systematic review of the evidence by international multidisciplinary experts aiming to decrease age at diagnosis. The current study tested the feasibility of implementing these guidelines in an American clinical setting.

METHODS

We designed a stepwise implementation process in a neonatal intensive care follow-up clinic. Efficacy was tested by comparing 10-month pre- and post-implementation periods. Clinic visit types, cerebral palsy diagnosis, provider competencies and perspectives, and balancing measures were analyzed.

RESULTS

Changes to infrastructure, assessments, scheduling algorithms, documentation and supports in diagnosis or counseling were successfully implemented. Number of three- to four-month screening visits increased (255 to 499, P < 0.001); mean age at diagnosis decreased (18 to 13 months, P < 0.001). Clinic team awareness of early diagnosis and interventions increased (P < 0.001). There was no decrease in family satisfaction with overall clinic function. Opportunities for improvements included documentation for transitioning patients, generalizabilty across hospital clinics, systematic identification of high-risk status during hospitalization, and need for cerebral palsy care guidelines for infants under age 2 years.

CONCLUSIONS

We demonstrated for the first time in a US clinical setting the feasibility of implementation of international early diagnosis and treatment guidelines for cerebral palsy. This process is adaptable to other settings and underscores the necessity of future research on cerebral palsy treatments in infancy.

Validation of an MRI Brain Injury and Growth Scoring System in Very Preterm Infants Scanned at 29- to 35-Week Postmenstrual Age

BACKGROUND AND PURPOSE

The diagnostic and prognostic potential of brain MR imaging before term-equivalent age is limited until valid MR imaging scoring systems are available. This study aimed to validate an MR imaging scoring system of brain injury and impaired growth for use at 29 to 35 weeks postmenstrual age in infants born at <31 weeks gestational age.

MATERIALS AND METHODS

Eighty-three infants in a prospective cohort study underwent early 3T MR imaging between 29 and 35 weeks' postmenstrual age (mean, 32⁺² ± 1⁺³ weeks; 49 males, born at median gestation of 28⁺⁴ weeks; range, 23⁺⁶-30⁺⁶ weeks; mean birthweight, 1068 ± 312 g). Seventy-seven infants had a second MR scan at term-equivalent age (mean, 40⁺⁶ ± 1⁺³ weeks). Structural images were scored using a modified scoring system which generated WM, cortical gray matter, deep gray matter, cerebellar, and global scores. Outcome at 12-months corrected age (mean, 12 months 4 days ± 1⁺² weeks) consisted of the Bayley Scales of Infant and Toddler Development, 3rd ed. (Bayley III), and the Neuro-Sensory Motor Developmental Assessment.

RESULTS

Early MR imaging global, WM, and deep gray matter scores were negatively associated with Bayley III motor (regression coefficient for global score β = -1.31; 95% CI, -2.39 to -0.23; P = .02), cognitive (β = -1.52; 95% CI, -2.39 to -0.65; P < .01) and the Neuro-Sensory Motor Developmental Assessment outcomes (β = -1.73; 95% CI, -3.19 to -0.28; P = .02). Early MR imaging cerebellar scores were negatively associated with the Neuro-Sensory Motor Developmental Assessment (β = -5.99; 95% CI, -11.82 to -0.16; P = .04). Results were reconfirmed at term-equivalent-age MR imaging.

CONCLUSIONS

This clinically accessible MR imaging scoring system is valid for use at 29 to 35 weeks postmenstrual age in infants born very preterm. It enables identification of infants at risk of adverse outcomes before the current standard of term-equivalent age.

Short-Term Effects of Hydrokinesiotherapy in Hospitalized Preterm Newborns

Background. In the neonatal intensive care unit (NICU) environment, preterm newborns are subject to environmental stress and numerous painful interventions. It is known that hydrokinesiotherapy promotes comfort and reduces stress because of the physiological properties of water. Objective. To evaluate the short-term effects of hydrokinesiotherapy on reducing stress in preterm newborns admitted to the NICU. Materials and Methods. Fifteen preterm newborns underwent salivary cortisol measurement, pain evaluation using the Neonatal Infant Pain Scale (NIPS), and heart rate, respiratory rate, and peripheral oxygen saturation measurements before and after the application of hydrokinesiotherapy. Results. The mean gestational age of the newborns was 34.2 ± 1.66 weeks, and the mean weight was 1823.3 ± 437.4 g. Immediately after application of hydrokinesiotherapy, a significant reduction was observed in salivary cortisol (p = 0.004), heart rate (p = 0.003), and respiratory rate (p = 0.004) and a significant increase was observed in peripheral oxygen saturation (p = 0.002). However, no significant difference was observed in the NIPS score (p > 0.05). Conclusion. In the present study, neonatal hydrotherapy promoted short-term relief from feelings of stress. Neonatal hydrokinesiotherapy may be a therapeutic alternative. However, this therapy needs to be studied in randomized, crossover, and blinded trials. This trial is registered with NCT02707731.

Early psychomotor development of low-risk preterm infants: Influence of gestational age and gender

BACKGROUND

The influence of gestational age and gender in the neurodevelopment of infants during the first year of age is not yet fully elucidated.

AIMS

The purpose of this study was to identify the early occurrence of neurodevelopmental differences, between very preterm, late preterm and term born infants and the possible influence of the gender on the neurodevelopment in early infancy.

METHODS

A total of 188 low-risk infants, 69 very preterms, 71 late-preterms, and 48 term infants were assessed at 3, 6, 9, 12 months corrected age using the Hammersmith Infant Neurological Examination (HINE). At two years of age infants performed the Mental Developmental Index (MDI) of the Bayley Scales of Infant Development.

RESULTS

The main results indicate that both very preterms and late-preterms showed significant lower global scores than term born infants at each evaluation (p < 0.001) at HINE and namely, at 3 months for the subsections "cranial nerve" and "posture" and at every age for "tone"; no gender differences has been evidenced in neurological performances. At the MDI, very preterms showed significant lower scores (p < 0.01) than both late-preterm and term born infants; gender differences were observed for preterms only (very and late), with best performances for females.

CONCLUSIONS

Our results point out the presence of gestational age and gender-dependent differences in the development of infants assessed during the first 2 years of life.