Neurodevelopmental consequences of preterm punctate white matter lesions: a systematic review

Diagnostic accuracy of early neonatal MRI in predicting adverse motor outcomes in children born preterm: Systematic review and meta-analysis

AIM

To examine the diagnostic accuracy of Early structural and diffusion-weighted magnetic resonance imaging (MRI) (acquired at < 36 weeks postmenstrual age) to detect cerebral palsy (CP) or other adverse motor outcomes at or beyond 3 years corrected age in infants born preterm.

METHOD

In this systematic review and meta-analysis, we searched the CINAHL, Embase, PubMed, and Web of Science databases for studies without language restrictions and a prospectively registered protocol up to October 2023. We extracted the study details, associations presented, and meta-analyses conducted with pooled sensitivity and specificity.

RESULTS

Twenty-seven articles met the overall inclusion criteria. White matter injury, cerebellar haemorrhage, intraventricular haemorrhage, and lower thalamic volume were associated with poorer motor outcomes. Abnormal Early structural MRI detected infants with a later diagnosis of CP (n = 448, eight studies) with a pooled sensitivity of 98% (95% confidence interval [CI] = 86-100), specificity of 75% (95% CI = 51-93), and adverse motor outcomes (n = 215, four studies), with a pooled sensitivity of 39% (95% CI = 20-59) and a specificity of 90% (95% CI = 88-94).

INTERPRETATION

Early abnormal structural MRI predicted later CP with high sensitivity and specificity, while specificity was higher than sensitivity in predicting adverse motor outcomes using the Movement Assessment Battery for Children, Second Edition. Further research into diagnostic accuracy and association between Early MRI and long-term motor outcomes is warranted.

Brain 3T magnetic resonance imaging in neonates: features and incidental findings from a research cohort enriched for preterm birth

BACKGROUND AND OBJECTIVES

The survival rate and patterns of brain injury after very preterm birth are evolving with changes in clinical practices. Additionally, incidental findings can present legal, ethical and practical considerations. Here, we report MRI features and incidental findings from a large, contemporary research cohort of very preterm infants and term controls.

METHODS

288 infants had 3T MRI at term-equivalent age: 187 infants born <32 weeks without major parenchymal lesions, and 101 term-born controls. T1-weighted, T2-weighted and susceptibility-weighted imaging were used to classify white and grey matter injury according to a structured system, and incidental findings described.

RESULTS

Preterm infants: 34 (18%) had white matter injury and 4 (2%) had grey matter injury. 51 (27%) infants had evidence of intracranial haemorrhage and 34 (18%) had punctate white matter lesions (PWMLs). Incidental findings were detected in 12 (6%) preterm infants. Term infants: no term infants had white or grey matter injury. Incidental findings were detected in 35 (35%); these included intracranial haemorrhage in 22 (22%), periventricular pseudocysts in 5 (5%) and PWMLs in 4 (4%) infants. From the whole cohort, 10 (3%) infants required referral to specialist services.

CONCLUSIONS

One-fifth of very preterm infants without major parenchymal lesions have white or grey matter abnormalities at term-equivalent age. Incidental findings are seen in 6% of preterm and 35% of term infants. Overall, 3% of infants undergoing MRI for research require follow-up due to incidental findings. These data should help inform consent procedures for research and assist service planning for centres using 3T neonatal brain MRI for clinical purposes.

Incidence of brain injuries in a large cohort of very preterm and extremely preterm infants at term-equivalent age: results of a single tertiary neonatal care center over 10 years

OBJECTIVES

Cerebral magnetic resonance imaging (cMRI) at term-equivalent age (TEA) can detect brain injury (BI) associated with adverse neurological outcomes in preterm infants. This study aimed to assess BI incidences in a large, consecutive cohort of preterm infants born < 32 weeks of gestation, the comparison between very (VPT, ≥ 28 + 0 to < 32 + 0 weeks of gestation) and extremely preterm infants (EPT, < 28 + 0 weeks of gestation) and across weeks of gestation.

METHODS

We retrospectively analyzed cMRIs at TEA of VPT and EPT infants born at a large tertiary center (2009-2018). We recorded and compared the incidences of BI, severe BI, intraventricular hemorrhage (IVH), periventricular hemorrhagic infarction (PVHI), cerebellar hemorrhage (CBH), cystic periventricular leukomalacia (cPVL), and punctate white matter lesions (PWML) between VPTs, EPTs, and across weeks of gestation.

RESULTS

We included 507 preterm infants (VPT, 335/507 (66.1%); EPT, 172/507 (33.9%); mean gestational age (GA), 28 + 2 weeks (SD 2 + 2 weeks); male, 52.1%). BIs were found in 48.3% of the preterm infants (severe BI, 12.0%) and increased with decreasing GA. IVH, PVHI, CBH, cPVL, and PWML were seen in 16.8%, 0.8%, 10.5%, 3.4%, and 18.1%, respectively. EPT vs. VPT infants suffered more frequently from BI (59.3% vs. 42.7%, p < 0.001), severe BI (18.6% vs. 8.7%, p = 0.001), IVH (31.9% vs. 9.0%, p < 0.001), and CBH (18.0% vs. 6.6%, p < 0.001).

CONCLUSION

Brain injuries are common cMRI findings among preterm infants with a higher incidence of EPT compared to VPT infants. These results may serve as reference values for clinical management and research.

CLINICAL RELEVANCE STATEMENT

Our results with regard to gestational age might provide valuable clinical insights, serving as a key reference for parental advice, structured follow-up planning, and enhancing research and management within the Neonatal Intensive Care Unit.

KEY POINTS

• Brain injury is a common cMRI finding in preterm infants seen in 48.3% individuals. • Extremely preterm compared to very preterm infants have higher brain injury incidences driven by brain injuries such as intraventricular and cerebellar hemorrhage. • Reference incidence values are crucial for parental advice and structured follow-up planning.

Molecular Mechanisms of Fetal and Neonatal Lupus: A Narrative Review of an Autoimmune Disease Transferal across the Placenta

This study, conducted by searching keywords such as "maternal lupus", "neonatal lupus", and "congenital heart block" in databases including PubMed and Scopus, provides a detailed narrative review on fetal and neonatal lupus. Autoantibodies like anti-Ro/SSA and anti-La/SSB may cross the placenta and cause complications in neonates, such as congenital heart block (CHB). Management options involve hydroxychloroquine, which is able to counteract some of the adverse events, although the drug needs to be used carefully because of its impact on the QTc interval. Advanced pacing strategies for neonates with CHB, especially in severe forms like hydrops, are also assessed. This review emphasizes the need for interdisciplinary care by rheumatologists, obstetricians, and pediatricians in order to achieve the best maternal and neonatal health in lupus pregnancies. This multidisciplinary approach seeks to improve the outcomes and management of the disease, decreasing the burden on mothers and their infants.

Prenatal Opioid Exposure and Risk for Adverse Brain and Motor Outcomes in Infants Born Premature

OBJECTIVE

To compare brain magnetic resonance imaging (MRI) biomarkers and neurodevelopmental test scores in infants born preterm with and without prenatal opioid exposure (POE).

STUDY DESIGN

We examined 395 preterm infants (≤32 weeks gestational age) who had term-equivalent brain MRIs, composite scores from the Bayley Scales of Infant and Toddler Development-III at 2 years corrected age, and POE data. MRI parameters included total/regional brain volumes and severe punctate white matter lesions (PWMLs). We conducted bivariable analysis and multivariable logistic regression analyses.

RESULTS

The mean ± SD gestational age was 29.3 ± 2.5 weeks; 35 (8.9%) had POE and 20 (5.1%) had severe PWML. Compared with unexposed infants, those with POE exhibited higher rates of severe PWML (17.1% vs 3.9%, respectively; P = .002); findings remained significant with an OR of 4.16 (95% CI, 1.26-13.68) after adjusting for confounders. On mediation analysis, the significant relationship between POE and severe PWML was not indirectly mediated through preterm birth/gestational age (OR, 0.93; 95% CI, 0.78-1.10), thus suggesting the association was largely driven by a direct adverse effect of POE on white matter. In multivariable analyses, POE was associated with a significantly lower score by -6.2 (95% CI, -11.8 to -0.6) points on the Bayley Scales of Infant and Toddler Development-III Motor subscale compared with unexposed infants.

CONCLUSIONS

POE was associated with severe PWML; this outcome may be a direct effect of POE rather than being mediated by premature birth. POE was also associated with worse motor development. Continued follow-up to understand the long-term effects of POE is warranted.

Angiogenic responses are enhanced by recombinant human erythropoietin in a model of periventricular white matter damage of neonatal rats through EPOR-ERK1 signaling

Recombinant human erythropoietin (rh-EPO) has been shown to stimulate neurogenesis and angiogenesis, both of which play crucial roles in the repair of brain injuries. Previously, we observed that rh-EPO treatment effectively reduced brain damage and enhanced angiogenesis in a neonatal rat model of periventricular white matter damage (PWMD). The objective of this research is to investigate the specific mechanism through which rh-EPO regulates angiogenesis following PWMD in premature neonates. We conducted experiments utilizing a neonatal PWMD model. Following rh-EPO treatment, the levels of erythropoietin receptor (EPOR) were found to be increased in the damaged brain of rats. Although the total amount of extracellular signal-regulated kinase (ERK), a downstream protein in the EPO signaling pathway, remained unchanged, there was clear upregulation of phosphorylated ERK1 (p-ERK1) levels. The increase in levels of p-ERK1 was inhibited by an ERK kinase inhibitor, while the total amount of ERK remained unchanged. Conversely, the levels of EPOR were not affected by the inhibitor. Notably, the introduction of rh-EPO led to a significant increase in the frequency of angiogenesis-related cells and the expression levels of angiogenic factors. However, these effects were nullified when the ERK pathway was blocked. These findings indicate that rh-EPO enhances angiogenic responses through the EPOR-ERK1 pathway in a neonatal PWMD model.

Early Extra-Uterine Growth Restriction in Very-Low-Birth-Weight Neonates with Normal or Mildly Abnormal Brain MRI: Effects on a 2-3-Year Neurodevelopmental Outcome

Extra-uterine growth restriction (EUGR) is a common complication and a known risk factor for impaired development in very-low-birth-weight (VLBW) neonates. We report a population of 288 patients with no or with low-grade MRI lesions scanned at a term equivalent age (TEA) born between 2012 and 2018. Griffiths Mental Development Scale II (GMDS II) at 2 and 3 years, preterm complications and weight growth were retrospectively analyzed. EUGR was defined for weight z-score ˂ 10 percentile at TEA, 6 and 12 months of correct age or as z-score decreased by 1-point standard deviation (SDS) from birth to TEA and from TEA to 6 months. Multivariate analysis showed that a higher weight z-score at 6 months is protective for the global developmental quotient (DQ) at 2 years (OR 0.74; CI 95% 0.59-0.93; p = 0.01). EUGR at 6 months was associated with worse locomotor, personal/social, language and performance DQ at 2 years and worse language and practical reasoning DQ at 3 years. In conclusion, a worse weight z-score at 6 months of age seems to be an independent risk factor for significantly reduced GMDS in many areas. These results suggest that we should invest more into post-discharge nutrition, optimizing family nutritional education.

High resolution and contrast 7 tesla MR brain imaging of the neonate

Introduction

Ultra-high field MR imaging offers marked gains in signal-to-noise ratio, spatial resolution, and contrast which translate to improved pathological and anatomical sensitivity. These benefits are particularly relevant for the neonatal brain which is rapidly developing and sensitive to injury. However, experience of imaging neonates at 7T has been limited due to regulatory, safety, and practical considerations. We aimed to establish a program for safely acquiring high resolution and contrast brain images from neonates on a 7T system.

Methods

Images were acquired from 35 neonates on 44 occasions (median age 39 + 6 postmenstrual weeks, range 33 + 4 to 52 + 6; median body weight 2.93 kg, range 1.57 to 5.3 kg) over a median time of 49 mins 30 s. Peripheral body temperature and physiological measures were recorded throughout scanning. Acquired sequences included T2 weighted (TSE), Actual Flip angle Imaging (AFI), functional MRI (BOLD EPI), susceptibility weighted imaging (SWI), and MR spectroscopy (STEAM).

Results

There was no significant difference between temperature before and after scanning (p = 0.76) and image quality assessment compared favorably to state-of-the-art 3T acquisitions. Anatomical imaging demonstrated excellent sensitivity to structures which are typically hard to visualize at lower field strengths including the hippocampus, cerebellum, and vasculature. Images were also acquired with contrast mechanisms which are enhanced at ultra-high field including susceptibility weighted imaging, functional MRI, and MR spectroscopy.

Discussion

We demonstrate safety and feasibility of imaging vulnerable neonates at ultra-high field and highlight the untapped potential for providing important new insights into brain development and pathological processes during this critical phase of early life.

Development of neonatal-specific sequences for portable ultralow field magnetic resonance brain imaging: a prospective, single-centre, cohort study

Background

Magnetic Resonance (MR) imaging is key for investigation of suspected newborn brain abnormalities. Access is limited in low-resource settings and challenging in infants needing intensive care. Portable ultralow field (ULF) MRI is showing promise in bedside adult brain imaging. Use in infants and children has been limited as brain-tissue composition differences necessitate sequence modification. The aim of this study was to develop neonatal-specific ULF structural sequences and test these across a range of gestational maturities and pathologies to inform future validation studies.

Methods

Prospective cohort study within a UK neonatal specialist referral centre. Infants undergoing 3T MRI were recruited for paired ULF (64mT) portable MRI by convenience sampling from the neonatal unit and post-natal ward. Key inclusion criteria: 1) Infants with risk or suspicion of brain abnormality, or 2) preterm and term infants without suspicion of major genetic, chromosomal or neurological abnormality. Exclusions: presence of contra-indication for MR scanning. ULF sequence parameters were optimised for neonatal brain-tissues by iterative and explorative design. Neuroanatomic and pathologic features were compared by unblinded review, informing optimisation of subsequent sequence generations in a step-wise manner. Main outcome: visual identification of healthy and abnormal brain tissues/structures. ULF MR spectroscopy, diffusion, susceptibility weighted imaging, arteriography, and venography require pre-clinical technical development and have not been tested.

Findings

Between September 23, 2021 and October 25, 2022, 102 paired scans were acquired in 87 infants; 1.17 paired scans per infant. Median age 9 days, median postmenstrual age 40+2 weeks (range: 31+3-53+4). Infants had a range of intensive care requirements. No adverse events observed. Optimised ULF sequences can visualise key neuroanatomy and brain abnormalities. In finalised neonatal sequences: T2w imaging distinguished grey and white matter (7/7 infants), ventricles (7/7), pituitary tissue (5/7), corpus callosum (7/7) and optic nerves (7/7). Signal congruence was seen within the posterior limb of the internal capsule in 10/11 infants on finalised T1w scans. In addition, brain abnormalities visualised on ULF optimised sequences have similar MR signal patterns to 3T imaging, including injury secondary to infarction (6/6 infants on T2w scans), hypoxia-ischaemia (abnormal signal in basal ganglia, thalami and white matter 2/2 infants on T2w scans, cortical highlighting 1/1 infant on T1w scan), and congenital malformations: polymicrogyria 3/3, absent corpus callosum 2/2, and vermian hypoplasia 3/3 infants on T2w scans. Sequences are susceptible to motion corruption, noise, and ULF artefact. Non-identified pathologies were small or subtle.

Interpretation

On unblinded review, optimised portable MR can provide sufficient contrast, signal, and resolution for neuroanatomical identification and detection of a range of clinically important abnormalities. Blinded validation studies are now warranted.

Funding

The Bill and Melinda Gates Foundation, the MRC, the Wellcome/EPSRC Centre for Medical Engineering, the MRC Centre for Neurodevelopmental Disorders, and the National Institute for Health Research (NIHR) Biomedical Research Centres based at Guy's and St Thomas' and South London & Maudsley NHS Foundation Trusts and King's College London.