Magnetic resonance imaging of white matter diseases of prematurity

Excitotoxic lesion in the corpus callosum of neonatal rats: A model for encephalopathy of prematurity

Encephalopathy of prematurity (EP) can develop in preterm infants exposed to risk factors like extreme prematurity, low birth weight, hypoxia, infections, and inflammation. These factors can induce excitotoxicity in the brain's gray and white matter, leading to the death of neurons and oligodendrocyte progenitors. Understanding the brain mechanisms of EP requires animal models. In this study, we generated an EP model by injecting N-methyl-D-aspartic acid (NMDA) into the corpus callosum (CC) of neonatal male rats on postnatal day (PND) 5. Rats were divided into five groups: Intact, Vehicle, and three doses of NMDA (3, 4, or 5 μg). On PND 20, we measured the volumes of the CC, motor cortex (MC), and lateral ventricles. The 5 µg NMDA dose caused the largest lesion. We later assessed these structures on PNDs 6, 10, 20, and 30 to monitor lesion progression. We also analyzed myelin basic protein (MBP) expression and counted NeuN-positive cells using immunofluorescent markers. NMDA groups showed reduced MBP expression and fewer NeuN-positive cells in the MC. Additionally, NMDA-treated rats exhibited increased motor activity in the open field and reduced fall latencies in the rotarod task compared to controls. In conclusion, our perinatal excitotoxic lesion model in rats demonstrates structural abnormalities, including decreased MBP and loss of NeuN-positive cells, alongside motor and habituation impairments, resembling those seen in human EP.

Incidence and Risk Factors of White Matter Lesions in Moderate and Late Preterm Infants

Background: Moderate and late preterm infants (32-36 weeks of gestation) are at significant risk of developmental impairments. Incidence of white matter lesions, which are associated with developmental impairments in very preterm infants, remains underreported in this population. This study aimed to assess the incidence and clinical risk factors associated with brain lesions, particularly white matter lesions, in moderate and late preterm infants using term-equivalent MRI. Methods: This prospective observational study included 195 preterm infants born at 32+0-36+6 weeks of gestation and admitted to a tertiary NICU between 2019 and 2020. MRI findings at term-equivalent age were evaluated. Clinical risk factors were analysed using logistic regression. Results: Among the 195 infants, 23.6% had brain lesions on MRI, with white matter lesions (73.9%), specifically punctate white matter lesions, being the most common form of lesions. Vaginal delivery (odds ratio (OR) = 3.102, 95% confidence interval (CI) = 1.250-7.696, p = 0.015), larger birth weight z-scores (OR = 1.702, 95% CI = 1.118-2.591, p = 0.013), and intubation (OR = 2.948, 95% CI = 1.269-6.850, p = 0.012) were significant risk factors for white matter lesions. Conclusions: White matter lesions, particularly punctate white matter lesions, are common in moderate and late preterm infants. These lesions are associated with perinatal factors suggestive of delayed transition and inflammation. Future research should focus on detailed clinical care measures and neurodevelopmental assessments to identify modifiable risk factors for brain injury.

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.

On punctate white matter lesions in preterm infants: Is ultrasound diagnosis feasible?

OBJECTIVES

To observe hyperechoic nodular or punctate white matter lesions (HNPL) in a population of preterm infants using routine cranial ultrasound (cUS), to describe the characteristics of HNPL, and to compare them with punctate white matter lesions (PWML) detected in magnetic resonance imaging (MRI).

DESIGN

Retrospective observational single-center cohort study.

SETTING

Level 2B neonatal unit in France.

PATIENTS

307 infants born <33 weeks gestation undergoing routine cUS with a total of 961 cUS performed.

MAIN OUTCOME MEASURES

Description of lesions (HNPL/PWML): presence or absence, number, size, location, and structural distribution.

RESULTS

Among the 307 included infants, 63 (20.5%) had at least one cerebral lesion, with 453 HNPL for 63 infants. HNPL were numerous (more than three in 66.6% of cases), primarily grouped in clusters (76.2%), located near the lateral ventricles (96.8%), and measuring more than 2 mm (79%). HNPL were diagnosed on day 29 on average and persisted until term. Overall, 43 MRI were performed in 307 infants, on average 18.9 days after last cUS, in 21 of those the indication was presence of HPNL on cUS. Of these 21 MRI, 14/21 presented 118 PWML compared to 173 HNPL on cUS. In the remaining MRI (7/21), no PWML were detected compared to 47 HNPL on cUS.

CONCLUSIONS

In our population of 307 preterm infants, cUS allowed the diagnosis of HNPL, with a large similarity to PWML in MRI and a better sensitivity. But in the absence of data on inter-observer variability, we cannot exclude overdiagnosis of HNPL.

Neuroimaging of Neonatal Stroke: Venous Focus

Perinatal venous infarcts are underrecognized clinically and at imaging. Neonates may be susceptible to venous infarcts because of hypercoagulable state, compressibility of the dural sinuses and superficial veins due to patent sutures, immature cerebral venous drainage pathways, and drastic physiologic changes of the brain circulation in the perinatal period. About 43% of cases of pediatric cerebral sinovenous thrombosis occur in the neonatal period. Venous infarcts can be recognized by ischemia or hemorrhage that does not respect an arterial territory. Knowledge of venous drainage pathways and territories can help radiologists recognize characteristic venous infarct patterns. Intraventricular hemorrhage in a term neonate with thalamocaudate hemorrhage should raise concern for internal cerebral vein thrombosis. A striato-hippocampal pattern of hemorrhage indicates basal vein of Rosenthal thrombosis. Choroid plexus hemorrhage may be due to obstruction of choroidal veins that drain the internal cerebral vein or basal vein of Rosenthal. Fan-shaped deep medullary venous congestion or thrombosis is due to impaired venous drainage into the subependymal veins, most commonly caused by germinal matrix hemorrhage in the premature infant and impeded flow in the deep venous system in the term infant. Subpial hemorrhage, an underrecognized hemorrhage stroke type, is often observed in the superficial temporal region, and its cause is probably multifactorial. The treatment of cerebral sinovenous thrombosis is anticoagulation, which should be considered even in the presence of intracranial hemorrhage. ©RSNA, 2024 Test Your Knowledge questions in the supplemental material and the slide presentation from the RSNA Annual Meeting are available for this article.

Neurodevelopmental Outcome at 3 Years of Age in Very Low Birth Weight Infants According to Brain Development and Lesions

BACKGROUND

During the last decades, severe brain lesions affecting very low birth weight (<1500 gr, VLBW) infants were gradually substituted by milder lesions with debatable prognoses.

OBJECTIVE

The objective of this study is to define type, frequency and 3 years of neurodevelopmental outcome of prematurity-related brain lesions in a modern cohort of VLBW infants.

METHODS

VLBW infants admitted to our NICU in 5 years period with brain MRI at term-equivalent age were included. MRI scans were reviewed to identify and grade white matter lesions (WML), intraventricular hemorrhage (IVH), and cerebellar hemorrhage (CBH). Linear measurements of brain size, biparietal width (BPW) and trans-cerebellar diameter (TCD) were carried out. Total maturation score (TMS) was calculated. Developmental Coefficients (DQ) on Griffiths Scale at 3 years of age were compared between patients with different types and grades of lesions and patients without lesions; possible correlations between linear brain measurements, brain maturation and outcome were explored.

RESULTS

Study included 407 patients. Of them, 187 (46%) had at least one brain lesion on MRI, while 37 (9%) had severe lesions. The most frequent lesion was IVH (28%), followed by WML (21%) and CBH (17%). Mild and severe IVH, moderate and severe WML and all grades of CBH were related to worst outcome at 3 years. In patients without lesions, small BPW and small TCD were associated with worse outcomes. No correlations were observed between TMS and outcome.

CONCLUSION

We have observed that even mild brain lesions have a negative influence on neurological outcome at 3 years of age.

Pharmacological pain and sedation interventions for the prevention of intraventricular hemorrhage in preterm infants on assisted ventilation - an overview of systematic reviews

BACKGROUND

Germinal matrix hemorrhage and intraventricular hemorrhage (GMH-IVH) may contribute to neonatal morbidity and mortality and result in long-term neurodevelopmental sequelae. Appropriate pain and sedation management in ventilated preterm infants may decrease the risk of GMH-IVH; however, it might be associated with harms.

OBJECTIVES

To summarize the evidence from systematic reviews regarding the effects and safety of pharmacological interventions related to pain and sedation management in order to prevent GMH-IVH in ventilated preterm infants.

METHODS

We searched the Cochrane Library August 2022 for reviews on pharmacological interventions for pain and sedation management to prevent GMH-IVH in ventilated preterm infants (< 37 weeks' gestation). We included Cochrane Reviews assessing the following interventions administered within the first week of life: benzodiazepines, paracetamol, opioids, ibuprofen, anesthetics, barbiturates, and antiadrenergics. Primary outcomes were any GMH-IVH (aGMH-IVH), severe IVH (sIVH), all-cause neonatal death (ACND), and major neurodevelopmental disability (MND). We assessed the methodological quality of included reviews using the AMSTAR-2 tool. We used GRADE to assess the certainty of evidence.

MAIN RESULTS

We included seven Cochrane Reviews and one Cochrane Review protocol. The reviews on clonidine and paracetamol did not include randomized controlled trials (RCTs) matching our inclusion criteria. We included 40 RCTs (3791 infants) from reviews on paracetamol for patent ductus arteriosus (3), midazolam (3), phenobarbital (9), opioids (20), and ibuprofen (5). The quality of the included reviews was high. The certainty of the evidence was moderate to very low, because of serious imprecision and study limitations. Germinal matrix hemorrhage-intraventricular hemorrhage (any grade) Compared to placebo or no intervention, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (risk ratio (RR) 0.89, 95% confidence interval (CI) 0.38 to 2.07; 2 RCTs, 82 infants; very low-certainty evidence); midazolam may result in little to no difference in the incidence of aGMH-IVH (RR 1.68, 95% CI 0.87 to 3.24; 3 RCTs, 122 infants; low-certainty evidence); the evidence is very uncertain about the effect of phenobarbital on aGMH-IVH (RR 0.99, 95% CI 0.83 to 1.19; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in aGMH-IVH (RR 0.85, 95% CI 0.65 to 1.12; 7 RCTs, 469 infants; low-certainty evidence); ibuprofen likely results in little to no difference in aGMH-IVH (RR 0.99, 95% CI 0.81 to 1.21; 4 RCTs, 759 infants; moderate-certainty evidence). Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on aGMH-IVH (RR 1.17, 95% CI 0.31 to 4.34; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, morphine may result in a reduction in aGMH-IVH (RR 0.28, 95% CI 0.09 to 0.87; 1 RCT, 46 infants; low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on aGMH-IVH (RR 0.65, 95% CI 0.40 to 1.07; 1 RCT, 88 infants; very low-certainty evidence). Severe intraventricular hemorrhage (grade 3 to 4) Compared to placebo or no intervention, the evidence is very uncertain about the effect of paracetamol on sIVH (RR 1.80, 95% CI 0.43 to 7.49; 2 RCTs, 82 infants; very low-certainty evidence) and of phenobarbital (grade 3 to 4) (RR 0.91, 95% CI 0.66 to 1.25; 9 RCTs, 732 infants; very low-certainty evidence); opioids may result in little to no difference in sIVH (grade 3 to 4) (RR 0.98, 95% CI 0.71 to 1.34; 6 RCTs, 1299 infants; low-certainty evidence); ibuprofen may result in little to no difference in sIVH (grade 3 to 4) (RR 0.82, 95% CI 0.54 to 1.26; 4 RCTs, 747 infants; low-certainty evidence). No studies on midazolam reported this outcome. Compared to ibuprofen, the evidence is very uncertain about the effects of paracetamol on sIVH (RR 2.65, 95% CI 0.12 to 60.21; 1 RCT, 30 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.08, 95% CI 0.00 to 1.43; 1 RCT, 46 infants; very low-certainty evidence). Compared to fentanyl, the evidence is very uncertain about the effect of morphine on sIVH (grade 3 to 4) (RR 0.59, 95% CI 0.18 to 1.95; 1 RCT, 163 infants; very low-certainty evidence). All-cause neonatal death Compared to placebo or no intervention, the evidence is very uncertain about the effect of phenobarbital on ACND (RR 0.94, 95% CI 0.51 to 1.72; 3 RCTs, 203 infants; very low-certainty evidence); opioids likely result in little to no difference in ACND (RR 1.12, 95% CI 0.80 to 1.55; 5 RCTs, 1189 infants; moderate-certainty evidence); the evidence is very uncertain about the effect of ibuprofen on ACND (RR 1.00, 95% CI 0.38 to 2.64; 2 RCTs, 112 infants; very low-certainty evidence). Compared to midazolam, the evidence is very uncertain about the effect of morphine on ACND (RR 0.31, 95% CI 0.01 to 7.16; 1 RCT, 46 infants; very low-certainty evidence). Compared to diamorphine, the evidence is very uncertain about the effect of morphine on ACND (RR 1.17, 95% CI 0.43 to 3.19; 1 RCT, 88 infants; very low-certainty evidence). Major neurodevelopmental disability Compared to placebo, the evidence is very uncertain about the effect of opioids on MND at 18 to 24 months (RR 2.00, 95% CI 0.39 to 10.29; 1 RCT, 78 infants; very low-certainty evidence) and at five to six years (RR 1.6, 95% CI 0.56 to 4.56; 1 RCT, 95 infants; very low-certainty evidence). No studies on other drugs reported this outcome.

AUTHORS' CONCLUSIONS

None of the reported studies had an impact on aGMH-IVH, sIVH, ACND, or MND. The certainty of the evidence ranged from moderate to very low. Large RCTs of rigorous methodology are needed to achieve an optimal information size to assess the effects of pharmacological interventions for pain and sedation management for the prevention of GMH-IVH and mortality in preterm infants. Studies might compare interventions against either placebo or other drugs. Reporting of the outcome data should include the assessment of GMH-IVH and long-term neurodevelopment.

Caffeine dosing regimens in preterm infants with or at risk for apnea of prematurity

BACKGROUND

Very preterm infants often require respiratory support and are therefore exposed to an increased risk of bronchopulmonary dysplasia (chronic lung disease) and later neurodevelopmental disability. Caffeine is widely used to prevent and treat apnea (temporal cessation of breathing) associated with prematurity and facilitate extubation. Though widely recognized dosage regimes have been used for decades, higher doses have been suggested to further improve neonatal outcomes. However, observational studies suggest that higher doses may be associated with harm.

OBJECTIVES

To determine the effects of higher versus standard doses of caffeine on mortality and major neurodevelopmental disability in preterm infants with (or at risk of) apnea, or peri-extubation.

SEARCH METHODS

We searched CENTRAL, MEDLINE, Embase, CINAHL, the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP), and clinicaltrials.gov in May 2022. The reference lists of relevant articles were also checked to identify additional studies.

SELECTION CRITERIA

We included randomized (RCTs), quasi-RCTs and cluster-RCTs, comparing high-dose to standard-dose strategies in preterm infants. High-dose strategies were defined as a high-loading dose (more than 20 mg of caffeine citrate/kg) or a high-maintenance dose (more than 10 mg of caffeine citrate/kg/day). Standard-dose strategies were defined as a standard-loading dose (20 mg or less of caffeine citrate/kg) or a standard-maintenance dose (10 mg or less of caffeine citrate/kg/day). We specified three additional comparisons according to the indication for commencing caffeine: 1) prevention trials, i.e. preterm infants born at less than 34 weeks' gestation, who are at risk for apnea; 2) treatment trials, i.e. preterm infants born at less than 37 weeks' gestation, with signs of apnea; 3) extubation trials: preterm infants born at less than 34 weeks' gestation, prior to planned extubation.

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane. We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean, standard deviation (SD), and mean difference (MD) for continuous data.  MAIN RESULTS: We included seven trials enrolling 894 very preterm infants (reported in Comparison 1, i.e. any indication). Two studies included infants for apnea prevention (Comparison 2), four studies for apnea treatment (Comparison 3) and two for extubation management (Comparison 4); in one study, indication for caffeine administration was both apnea treatment and extubation management (reported in Comparison 1, Comparison 3 and Comparison 4). In the high-dose groups, loading and maintenance caffeine doses ranged from 30 mg/kg to 80 mg/kg, and 12 mg/kg to 30 mg/kg, respectively; in the standard-dose groups, loading and maintenance caffeine doses ranged from 6 mg/kg to 25 mg/kg, and 3 mg/kg to 10 mg/kg, respectively. Two studies had three study groups: infants were randomized in three different doses (two of them matched our definition of high dose and one matched our definition of standard dose); high-dose caffeine and standard-dose caffeine were compared to theophylline administration (the latter is included in a separate review). Six of the seven included studies compared high-loading and high-maintenance dose to standard-loading and standard-maintenance dose, whereas in one study standard-loading dose and high-maintenance dose was compared to standard-loading dose and standard-maintenance dose. High-dose caffeine strategies (administration for any indication) may have little or no effect on mortality prior to hospital discharge (risk ratio (RR) 0.86, 95% confidence of interval (CI) 0.53 to 1.38; risk difference (RD) -0.01, 95% CI -0.05 to 0.03; I² for RR and RD = 0%; 5 studies, 723 participants; low-certainty evidence). Only one study enrolling 74 infants reported major neurodevelopmental disability in children aged three to five years (RR 0.79, 95% CI 0.51 to 1.24; RD -0.15, 95% CI -0.42 to 0.13; 46 participants; very low-certainty evidence). No studies reported the outcome mortality or major neurodevelopmental disability in children aged 18 to 24 months and 3 to 5 years. Five studies reported bronchopulmonary dysplasia at 36 weeks' postmenstrual age (RR 0.75, 95% CI 0.60 to 0.94; RD -0.08, 95% CI -0.15 to -0.02; number needed to benefit (NNTB) = 13; I² for RR and RD = 0%; 723 participants; moderate-certainty evidence). High-dose caffeine strategies may have little or no effect on side effects (RR 1.66, 95% CI 0.86 to 3.23; RD 0.03, 95% CI -0.01 to 0.07; I² for RR and RD = 0%; 5 studies, 593 participants; low-certainty evidence). The evidence is very uncertain for duration of hospital stay (data reported in three studies could not be pooled in meta-analysis because outcomes were expressed as medians and interquartile ranges) and seizures (RR 1.42, 95% CI 0.79 to 2.53; RD 0.14, 95% CI -0.09 to 0.36; 1 study, 74 participants; very low-certainty evidence). We identified three ongoing trials conducted in China, Egypt, and New Zealand.

AUTHORS' CONCLUSIONS

High-dose caffeine strategies in preterm infants may have little or no effect on reducing mortality prior to hospital discharge or side effects. We are very uncertain whether high-dose caffeine strategies improves major neurodevelopmental disability, duration of hospital stay or seizures. No studies reported the outcome mortality or major neurodevelopmental disability in children aged 18 to 24 months and 3 to 5 years. High-dose caffeine strategies probably reduce the rate of bronchopulmonary dysplasia. Recently completed and future trials should report long-term neurodevelopmental outcome of children exposed to different caffeine dosing strategies in the neonatal period. Data from extremely preterm infants are needed, as this population is exposed to the highest risk for mortality and morbidity. However, caution is required when administering high doses in the first hours of life, when the risk for intracranial bleeding is highest. Observational studies might provide useful information regarding potential harms of the highest doses.

Stem cell-based interventions for the prevention and treatment of intraventricular haemorrhage and encephalopathy of prematurity in preterm infants

BACKGROUND

Germinal matrix-intraventricular haemorrhage (GMH-IVH) and encephalopathy of prematurity (EoP) remain substantial issues in neonatal intensive care units worldwide. Current therapies to prevent or treat these conditions are limited. Stem cell-based therapies offer a potential therapeutic approach to repair, restore, or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal studies. This is an update of the 2019 review, which did not include EoP.

OBJECTIVES

To evaluate the benefits and harms of stem cell-based interventions for prevention or treatment of GM-IVH and EoP in preterm infants.

SEARCH METHODS

We used standard, extensive Cochrane search methods. The latest search was April 2022.

SELECTION CRITERIA

We attempted to include randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing 1. stem cell-based interventions versus control; 2. mesenchymal stromal cells (MSCs) of type or source versus MSCs of other type or source; 3. stem cell-based interventions other than MSCs of type or source versus stem cell-based interventions other than MSCs of other type or source; or 4. MSCs versus stem cell-based interventions other than MSCs. For prevention studies, we included extremely preterm infants (less than 28 weeks' gestation), 24 hours of age or less, without ultrasound diagnosis of GM-IVH or EoP; for treatment studies, we included preterm infants (less than 37 weeks' gestation), of any postnatal age, with ultrasound diagnosis of GM-IVH or with EoP.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methods. Our primary outcomes were 1. all-cause neonatal mortality, 2. major neurodevelopmental disability, 3. GM-IVH, 4. EoP, and 5. extension of pre-existing non-severe GM-IVH or EoP. We planned to use GRADE to assess certainty of evidence for each outcome.

MAIN RESULTS

We identified no studies that met our inclusion criteria. Three studies are currently registered and ongoing. Phase 1 trials are described in the 'Excluded studies' section.

AUTHORS' CONCLUSIONS

No evidence is currently available to evaluate the benefits and harms of stem cell-based interventions for treatment or prevention of GM-IVH or EoP in preterm infants. We identified three ongoing studies, with a sample size range from 20 to 200. In two studies, autologous cord blood mononuclear cells will be administered to extremely preterm infants via the intravenous route; in one, intracerebroventricular injection of MSCs will be administered to preterm infants up to 34 weeks' gestational age.

Case report: Bilateral damage to the immature optic radiation and secondary massive loss of retinal ganglion cells causing tunnel vision

We describe the case of a 30-year-old woman, who needed a formal report on her visual impairment to seek support from society. She was born preterm, and during her neonatal period, she suffered from bilateral intraventricular hemorrhage (IVH) grade 3, a condition that can cause cerebral visual impairment (CVI) due to damage to the retro-geniculate visual pathways. Individuals with such brain damage of this severity are often restricted by cerebral palsy (CP) and intellectual disability, and thus have a limited ability to cooperate in the assessment of visual function. However, our patient was capable of providing reliable test results, and she manifested only a small island of central vision in each eye, with additional reduced visual acuities. She cooperated well in examinations involving MRI of the brain, optical coherence tomography (OCT) of retinal ganglion cells, and multi-focal visual evoked potentials, with each test providing information about potential limitations in the structural prerequisites for visual function. What distinguishes our case is the severity of the damage to the optic radiations and the massive secondary loss of most of her retinal ganglion cells (GCs). However, there is some measurable visual function, which may be due to developmental neuroplasticity during early development, when surviving GCs prioritize the central visual field. Despite her visual difficulties, she is a keen portrait painter. Our patient may be representative of, and a spokesperson for, other individuals with extensive brain damage of the same etiology, who are unable to perform perimetric tests and therefore run the risk of not being recognized as severely visually impaired, and consequently, not being given the best conditions for habilitation. OCT may serve as a helpful diagnostic tool. Aim: This study aims to describe visual behavior and practical applications of visual function in relation to structural prerequisites for visual function.

Cystic Periventricular Leukomalacia Worsens Developmental Outcomes of Very-Low-Birth Weight Infants with Intraventricular Hemorrhage-A Nationwide Cohort Study

Cystic periventricular leukomalacia (cPVL) is a major brain injury involving periventricular white matter that leads to neurodevelopmental impairment in very-low-birth weight (VLBW) infants. We investigated the neurodevelopmental outcomes (motor, cognition, visual, and hearing) of 5734 VLBW infants born between 2013 and 2019 and enrolled in the Korean Neonatal Network. Cranial ultrasound results were stratified by the presence of cPVL and severity of intraventricular hemorrhage (IVH) (no, low-grade [I/II], high-grade [III]). Neurodevelopmental impairment was evaluated using cerebral palsy for motor and Bayley Scales of Infant Development for cognition. cPVL was associated with motor, cognitive, and visual impairments in those without IVH and with low-grade IVH in pairwise comparisons (Cochran−Mantel−Haenszel p < 0.001). Conversely, cPVL was non-significantly correlated with cognitive impairment in high-grade IVH. In regression models adjusted for neonatal variables, isolated cPVL was strongly associated with motor (22.04; 11.39−42.63) and cognitive (3.10; 1.54−6.22) impairments. This study underlines the overall considerable significance of cPVL on NDI with divergent impacts depending on the severity of IVH and developmental indices.

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

OBJECTIVES

To evaluate punctate white matter lesion (PWML) influence in preterm infants on the long-term neurodevelopmental outcome (NDO).

METHODS

PubMed and EMBASE were searched from January 1, 2000, to May 31, 2021. Studies were included in which PWML in preterm infants on MRI around term-equivalent age (TEA) and NDO at ≥12 months were reported. Study and patient characteristics and NDO on motor, cognitive, and behavioral domains were extracted. The quality of studies was assessed using the Cochrane-approved Quality in Prognosis Studies tool.

RESULTS

This analysis included nine studies with a total of 1655 patients. Mean incidence of isolated PWML was 22.1%. All studies showed a relationship between PWML and motor delay. Two studies found a significant correlation between cognitive and behavioral outcomes and PWML. Number and PWML location are related to severity and impairment types.

LIMITATIONS

PWML were not always separately described from generalized WMI, only studies with imaging around TEA were included, and studies were heterogenic in design and quality.

CONCLUSIONS

PWML is common in preterm infants and predictive of adverse NDO, in particular on motor outcomes and less on cognitive and behavioral outcomes. The type and severity of impairments are related to the number and location of PMWL.

IMPACT

PWML is common in preterm infants and seems predictive of adverse NDO. DWI and SWI MRI sequences are informative because the different patterns suggest a difference in the underlying pathology. The type and severity of impairments are related to the number and location of PMWL. Our review can inform clinicians and parents about the NDO of preterm infants with a diagnosis of PWML. Prospective neuroimaging case-control cohort studies are recommended.

Routine Use of Cerebral Magnetic Resonance Imaging in Infants Born Extremely Preterm

OBJECTIVE

To describe cerebral abnormalities and their risk factors in a contemporary cohort of infants born extremely premature after the introduction of routine cerebral magnetic resonance imaging (cMRI) at term-equivalent age.

STUDY DESIGN

All cMRI examinations performed during November 2017 and November 2020, based on a standardized neonatal cMRI protocol, were included into analysis. Pathologies were retrospectively classified into 3 categories: intraventricular hemorrhage (IVH), white matter disease, and cerebellar injuries.

RESULTS

A total of 198 cMRI examinations were available for analyses; 93 (47%) showed abnormalities, most frequently IVH (n = 65, 33%), followed by cerebellar injuries (n = 41, 21%), and white matter disease (n = 28, 14%). Severe abnormalities were found in 18% of patients (n = 36). Significant clinical risk factors for abnormalities on cMRI were lower Apgar scores, lower umbilical artery and first neonatal pH, asphyxia, blood culture-proven sepsis (especially late-onset), and prolonged need of respiratory support and supplemental oxygen.

CONCLUSIONS

After routine cMRI, without preconfirmed pathology by cranial ultrasonography, low-grade IVH, noncystic white matter disease, and cerebellar injuries were the most frequently found abnormalities. The clinical value and long-term benefit of the detection of these low-grade pathologies have yet to be confirmed.

Quantitative susceptibility mapping as a measure of cerebral oxygenation in neonatal piglets

Prominence of cerebral veins using susceptibility weighted magnetic resonance imaging (SWI) has been used as a qualitative indicator of cerebral venous oxygenation (CvO2). Quantitative susceptibility mapping (QSM) adds more precision to the assessment of CvO2, but has not been applied to neonatal hypoxic ischemic injury (HII). We proposed to study QSM measures of venous susceptibility and their correlation with direct measures of brain oxygenation and cerebral blood flow (CBF) in the neonatal piglet. The association of QSM intravascular cerebral venous susceptibility, with brain tissue O2 tension, CBF, cortical tissue oxyhemoglobin saturation, and the partial pressure of oxygen in arterial blood measurement during various oxygenation states was determined by linear regression. Compared to normoxia, venous susceptibility in the straight sinus increased 56.8 ± 25.4% during hypoxia, while decreasing during hyperoxia (23.5 ± 32.9%) and hypercapnia (23.3 ± 73.1%), which was highly correlated to all other measures of oxygenation (p < 0.0001) but did not correlate to CBF (p = 0.82). These findings demonstrate a strong relationship between venous susceptibility and brain tissue O2 tension. Our results suggest that QSM-derived venous susceptibility is sensitive to cerebral oxygenation status across various oxygenation states.

White Matter Injury in Preterm Infants: Pathogenesis and Potential Therapy From the Aspect of the Gut–Brain Axis

Very preterm infants who survive are at high risk of white matter injury (WMI). With a greater understanding of the pathogenesis of WMI, the gut microbiota has recently drawn increasing attention in this field. This review tries to clarify the possible mechanisms behind the communication of the gut bacteria and the immature brain via the gut–brain axis. The gut microbiota releases signals, such as microbial metabolites. These metabolites regulate inflammatory and immune responses characterized by microglial activation, which ultimately impact the differentiation of pre-myelinating oligodendrocytes (pre-OLs) and lead to WMI. Moreover, probiotics and prebiotics emerge as a promising therapy to improve the neurodevelopmental outcome. However, future studies are required to clarify the function of these above products and the optimal time for their administration within a larger population. Based on the existing evidence, it is still too early to recommend probiotics and prebiotics as effective treatments for WMI.

Hypoxic Ischemic Encephalopathy (HIE) in Term and Preterm Infants

Hypoxic-ischemic syndrome (HIS) and Hypoxic-ischemic encephalopathy (HIE) are conditions that affect term and premature babies, with different pathophysiology and different brain disorders. HIE appears in 1-6 / 1000 live births and 26/1000 live births in developing countries. 15-20% die in the early neonatal period, while surviving babies have severe neurological impairment, including cerebral palsy, epilepsy, visual and hearing impairment, cognitive impairment, intellectual, behavioural, and social disorders. The hypoxic-ischemic event occurs before, during or after birth. The reasons may be related to the mother, the way of birth, the placenta, and the newborn. The criteria for diagnosis of HIE include a combination of perinatal factors, the need for resuscitation, standard neurological examinations, neurophysiological monitoring, neuroimaging methods and biochemical markers. The most effective treatment for HIE is hypothermia in combination with pharmacological therapy. HIE and HIS are problem that still persist in developing countries due to inadequate obstetric care, neonatal resuscitation, and hypothermia. Current and emerging research for HIE examines new markers for early recognition, treatment, and appropriate neuroprotection of high-risk term and premature infants.

Adaptations in the Hippocampus during the Fetal to Neonatal Transition in Guinea Pigs

(Background) The transition from in utero to ex utero life is associated with rapid changes in the brain that are both protective and required for newborn functional activities, allowing adaption to the changing environment. The current study aimed to reveal new insights into adaptations required for normal ongoing brain development and function after birth. (Methods) Time-mated dams were randomly allocated to fetal collection at gestational age 68 or spontaneous term delivery followed by neonatal collection within 24 h of birth. Immunohistochemistry was performed to examine mature myelin formation and neuronal nuclei coverage. RT-PCR was used to quantify the mRNA expression of key markers of the oligodendrocyte lineage, neuronal development, and GABAergic/glutamatergic pathway maturation. (Results) Mature myelin was reduced in the subcortical white matter of the neonate, whilst neuronal nuclei coverage was increased in both the hippocampus and the overlying cortical region. Increased mRNA expression in neonates was observed for oligodendrocyte and neuronal markers. There were also widespread mRNA changes across the inhibitory GABAergic and excitatory glutamatergic pathways in neonates. (Conclusions) This study has identified important adaptations in the expression of key neurodevelopmental structures, including oligodendrocytes and neurons, that may be essential for appropriate transition in neurodevelopment to the postnatal period.

Erythropoietin as a Neuroprotective Drug for Newborn Infants: Ten Years after the First Use

Protective strategies against perinatal brain injury represent a major challenge for modern neonatology. Erythropoietin (Epo) enhances endogenous mechanisms of repair and angiogenesis. In order to analyse the newest evidence on the role of Epo in prematurity, hypoxic ischemic encephalopathy (HIE) and perinatal stroke, a critical review using 2020 PRISMA statement guidelines was conducted. This review uncovered 26 clinical trials examining the use of Epo for prematurity and brain injury-related outcomes. The effects of Epo on prematurity were analysed in 16 clinical trials. Erythropoietin was provided until 32–35 weeks of corrected postnatal age with a dosage between 500–3000 UI/kg/dose. Eight trials reported the Epo effects on HIE term newborn infants: Erythropoietin was administered in the first weeks of life, at different multiple doses between 250–2500 UI/kg/dose, as either an adjuvant therapy with hypothermia or a substitute for hypothermia. Two trials investigated Epo effects in perinatal stroke. Erythropoietin was administered at a dose of 1000 IU/kg for three days. No beneficial effect in improving morbidity was observed after Epo administration in perinatal stroke. A positive effect on neurodevelopmental outcome seems to occur when Epo is used as an adjuvant therapy with hypothermia in the HIE newborns. Administration of Epo in preterm infants still presents inconsistencies with regard to neurodevelopmental outcome. Clinical trials show significant differences mainly in target population and intervention scheme. The identification of specific markers and their temporal expression at different time of recovery after hypoxia-ischemia in neonates might be implemented to optimize the therapeutic scheme after hypoxic-ischemic injury in the developing brain. Additional studies on tailored regimes, accounting for the risk stratification of brain damage in newborns, are required.

Cognitive performance during adulthood in a rat model of neonatal diffuse white matter injury

RATIONALE

Infants born prematurely risk developing diffuse white matter injury (WMI), which is associated with impaired cognitive functioning and an increased risk of autism spectrum disorder. Recently, our rat model of preterm diffuse WMI induced by combined fetal inflammation and postnatal hypoxia showed impaired motor performance, anxiety-like behaviour and autism-like behaviour in juvenile rats, especially males. Immunohistochemistry showed delayed myelination in the sensory cortex and impaired oligodendrocyte differentiation.

OBJECTIVE

To assess long-term cognitive deficits in this double-hit rat model of diffuse WMI, animals were screened on impulsivity, attention and cognitive flexibility in adulthood using the 5-choice serial reaction time task (5CSRTT) and a probabilistic reversal learning task, tests that require a proper functioning prefrontal cortex. Thereafter, myelination deficits were evaluated by immunofluorescent staining in adulthood.

RESULTS

Overall, little effect of WMI or sex was found in the cognitive tasks. WMI animals showed subtle differences in performance in the 5CSRTT. Manipulating 5CSRTT parameters resulted in performance patterns previously seen in the literature. Sex differences were found in perseverative responses and omitted trials: female WMI rats seem to be less flexible in the 5CSRTT but not in the reversal learning task. Males collected rewards faster in the probabilistic reversal learning task. These findings are explained by temporally rather than permanently affected myelination and by the absence of extensive injury to prefrontal cortical subregions, confirmed by immunofluorescent staining in both adolescence and adulthood.

CONCLUSION

This rat model of preterm WMI does not lead to long-term cognitive deficits as observed in prematurely born human infants.

Adenosine Blood Level: A Biomarker of White Matter Damage in Very Low Birth Weight Infants

BACKGROUND

Very low birth weight infants are at risk of developing periventricular white matter lesions. We previously reported high blood adenosine levels in premature infants and infants with low birth weight. We asked whether blood adenosine levels could be related to the vulnerability of the maturing white matter to develop lesions. The present study aims at finding a biomarker for the early detection of brain white matter lesions that can profoundly influence the neurodevelopmental outcome, whose pathophysiology is still unclear.

METHODS

Dried blood spots were prospectively collected for the newborn screening program and adenosine concentration measurements. Fifty-six newborns who tested four times for blood adenosine concentration (at days 3, 15, 30, and 40 post-birth) were included in the program. All infants underwent brain MRI at term equivalent age. Neurodevelopmental outcomes were studied with Griffiths Mental Development Scales (GMDS) at 12 ± 2 months corrected age.

RESULTS

Blood adenosine concentration increased over time from a median of 0.75 μM at Day 3 to 1.46 μM at Day 40. Adenosine blood concentration >1.58 μM at Day 15 was significantly associated with brain white matter lesions at MRI (OR (95 % CI) of 50.0 (3.6-688.3), p-value < 0.001). A moderate negative correlation between adenosine at 15 days of life and GMDS at 12 ± 2 months corrected age was found.

CONCLUSION

These findings suggest a potential role for blood adenosine concentration as a biomarker of creberal white matter lesions in very low birth weight infants.

Clinical experience with an in-NICU magnetic resonance imaging system

OBJECTIVE

To evaluate the utility of the 1 Tesla (1 T) Embrace (Aspect Imaging) neonatal magnetic resonance imaging (MRI) scanner in a level III NICU.

STUDY DESIGN

Embrace brain MRI findings for 207 infants were reviewed, including 32 scans directly compared within 5 days with imaging on a 3 T Siemens Trio. Clinical MRI scan abnormalities were also compared to cranial ultrasound findings.

RESULT

Of the 207 Embrace brain MRIs, 146 (70.5%) were obtained for clinical indications and 61 (29.5%) were research cases. Abnormal findings were found in 80 scans, most commonly hemorrhage and white matter injury. Notable findings included a stroke, medullary brainstem tumor, and polymicrogyria. In the 1 T versus 3 T comparison cohort, results were discordant in only one infant with punctate foci of susceptibility noted only on the 3 T scan.

CONCLUSION

The Embrace MRI scans detected clinically relevant brain abnormalities and in a subset were clinically comparable to 3 T scans.

Continuous glucose monitoring for the prevention of morbidity and mortality in preterm infants

BACKGROUND

Preterm infants are susceptible to hyperglycaemia and hypoglycaemia, which may lead to adverse neurodevelopment. The use of continuous glucose monitoring (CGM) devices might help in keeping glucose levels in the normal range, and reduce the need for blood sampling. However, the use of CGM might be associated with harms in the preterm infant.

OBJECTIVES

To assess the benefits and harms of CGM versus intermittent modalities to measure glycaemia in preterm infants 1. at risk of hypoglycaemia or hyperglycaemia; 2. with proven hypoglycaemia; or 3. with proven hyperglycaemia.

SEARCH METHODS

We searched CENTRAL (2021, Issue 4); PubMed; Embase; and CINAHL in April 2021. We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomized controlled trials (RCTs) and quasi-RCTs.

SELECTION CRITERIA

We included RCTs and quasi-RCTs comparing the use of CGM versus intermittent modalities to measure glycaemia in preterm infants at risk of hypoglycaemia or hyperglycaemia; with proven hypoglycaemia; or with proven hyperglycaemia.

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of included trials using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria (assessing randomization, blinding, loss to follow-up, and handling of outcome data). We evaluated treatment effects using a fixed-effect model with risk ratio (RR) with 95% confidence intervals (CI) for categorical data and mean, standard deviation (SD), and mean difference (MD) for continuous data. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

We included four trials enrolling 300 infants in our updated review. We included one new study and excluded another previously included study (because the inclusion criteria of the review have been narrowed). We compared the use of CGM to intermittent modalities in preterm infants at risk of hypoglycaemia or hyperglycaemia; however, one of these trials was analyzed separately because CGM was used as a standalone device, without being coupled to a control algorithm as in the other trials. We identified no studies in preterm infants with proven hypoglycaemia or hyperglycaemia.  None of the four included trials reported the neurodevelopmental outcome (i.e. the primary outcome of this review), or seizures. The effect of the use of CGM on mortality during hospitalization is uncertain (RR 0.59, 95% CI 0.16 to 2.13; RD -0.02, 95% CI -0.07 to 0.03; 230 participants; 2 studies; very low-certainty evidence). The certainty of the evidence was very low for all outcomes because of limitations in study design, and imprecision of estimates. One study is ongoing (estimated sample size 60 infants) and planned to be completed in 2022.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine if CGM affects preterm infant mortality or morbidities.  We are very uncertain of the safety of CGM and the available management algorithms, and many morbidities remain unreported. Preterm infants at risk of hypoglycaemia or hyperglycaemia were enrolled in all four included studies. No studies have been conducted in preterm infants with proven hypoglycaemia or hyperglycaemia. Long-term outcomes were not reported. Events of necrotizing enterocolitis, reported in the study published in 2021, were lower in the CGM group. However, the effect of CGM on this outcome remains very uncertain. Clinical trials are required to determine the most effective CGM and glycaemic management regimens in preterm infants before larger studies can be performed to assess the efficacy of CGM for reducing mortality, morbidity, and long-term neurodevelopmental impairments.

The Role of Extracellular Vesicles in the Developing Brain: Current Perspective and Promising Source of Biomarkers and Therapy for Perinatal Brain Injury

This comprehensive review focuses on our current understanding of the proposed physiological and pathological functions of extracellular vesicles (EVs) in the developing brain. Furthermore, since EVs have attracted great interest as potential novel cell-free therapeutics, we discuss advances in the knowledge of stem cell- and astrocyte-derived EVs in relation to their potential for protection and repair following perinatal brain injury. This review identified 13 peer-reviewed studies evaluating the efficacy of EVs in animal models of perinatal brain injury; 12/13 utilized mesenchymal stem cell-derived EVs (MSC-EVs) and 1/13 utilized astrocyte-derived EVs. Animal model, method of EV isolation and size, route, timing, and dose administered varied between studies. Notwithstanding, EV treatment either improved and/or preserved perinatal brain structures both macroscopically and microscopically. Additionally, EV treatment modulated inflammatory responses and improved brain function. Collectively this suggests EVs can ameliorate, or repair damage associated with perinatal brain injury. These findings warrant further investigation to identify the optimal cell numbers, source, and dosage regimens of EVs, including long-term effects on functional outcomes.

Incidental findings on brain MR imaging of asymptomatic term neonates in the Developing Human Connectome Project

BACKGROUND

Interpretation of incidental findings on term neonatal MRI brain imaging can be challenging as there is a paucity of published normative data on asymptomatic term neonates. Reporting radiologists and clinicians need to be familiar with these incidental findings to avoid over-investigation and misinterpretation particularly in relation to neurodevelopmental outcome. This study aimed to determine the prevalence of incidental findings in a large group of asymptomatic term neonates participating in the Developing Human Connectome Project (dHCP) who were invited for neurodevelopmental assessment at 18 months.

METHODS

We retrospectively reviewed MRI brain scans performed on 500 term neonates enrolled in the dHCP study between 2015 and 2019 with normal clinical examination. We reviewed the results of the Bayley Scales of Infant and Toddler Development (Bayley III) applied to participants who attended for neurodevelopmental follow-up at 18 months. Scores considered "delayed" if <70 on language, cognitive or motor scales.

FINDINGS

Incidental findings were observed in 47% of term infants. Acute cerebral infarcts were incidentally noted in five neonates (1%). More common incidental findings included punctate white matter lesions (PWMLs) (12%) and caudothalamic subependymal cysts (10%). The most frequent incidental finding was intracranial haemorrhage (25%), particularly subdural haemorrhage (SDH). SDH and PWMLs were more common in infants delivered with ventouse-assistance versus other delivery methods.Neurodevelopmental results were available on 386/500 (77%). 14 infants had a language score < 70 (2 SD below the mean). Of the 386 infants with neurodevelopmental follow up at 18 months, group differences in motor and language scores between infants with and without incidental findings were not significant (p = 0·17 and p = 0·97 respectively). Group differences in cognitive scores at 18 months between infants with (median (interquartile range) -100 (95-105)) and without (100 (95-110)) incidental findings were of small effect size to suggest clinical significance (Cliff's d = 0·15; p<0·05).

INTERPRETATION

Incidental findings are relatively common on brain MRI in asymptomatic term neonates, majority are clinically insignificant with normal neurodevelopment at 18 months.

FUNDING

This work was supported by the European Research Council under the European Union's Seventh Framework Programme (FP7/20072013/ERC grant agreement no. [319456] dHCP project), by core funding from the Wellcome/EPSRC Centre for Medical Engineering [WT203148/Z/16/Z] and by the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy's and St Thomas' NHS Foundation Trust and King's College London and/or the NIHR Clinical Research Facility. The views expressed are those of the authors and not necessarily those of the NHS, the NIHR or the Department of Health and Social Care.

Nosological Differences in the Nature of Punctate White Matter Lesions in Preterm Infants

Background: The pathogenesis of punctuate white matter lesions (PWMLs), a mild form of white matter damage observed in preterm infants, is still a matter of debate. Susceptibility-weighted imaging (SWI) allows to differentiate PWMLs based on the presence (SWI+) or absence (SWI-) of hemosiderin, but little is known about the significance of this distinction. This retrospective study aimed to compare neuroradiological and clinical characteristics of SWI+ and SWI- PWMLs. Materials and Methods: MR images of all VLBW infants scanned consecutively at term-equivalent age between April 2012 and May 2018 were retrospectively reviewed, and infants with PWMLs defined as small areas of high T1 and/or low T2 signal in the periventricular white matter were selected and included in the study. Each lesion was analyzed separately and characterized by localization, organization pattern, and distance from the lateral ventricle. Clinical data were retrieved from the department database. Results: A total of 517 PWMLs were registered in 81 patients, with 93 lesions (18%) visible on SWI (SWI+), revealing the presence of hemosiderin deposits. On univariate analysis, compared to SWI- PWML, SWI+ lesions were closer to the ventricle wall, more frequently organized in linear pattern and associated with lower birth weight, lower gestational age, lower admission temperature, need for intubation, bronchopulmonary dysplasia, retinopathy of prematurity, and presence of GMH-IVH. On multivariate analysis, closer distance to the ventricle wall on axial scan and lower birth weight were associated with visibility of PMWLs on SWI (p = 0.003 and p = 0.0001, respectively). Conclusions: Our results suggest a nosological difference between SWI+ and SWI- PWMLs. Other prospective studies are warranted to corroborate these observations.

Interventions to minimize blood loss in very preterm infants-A systematic review and meta-analysis

Blood loss in the first days of life has been associated with increased morbidity and mortality in very preterm infants. In this systematic review we included randomized controlled trials comparing the effects of interventions to preserve blood volume in the infant from birth, reduce the need for sampling, or limit the blood sampled. Mortality and major neurodevelopmental disabilities were the primary outcomes. Included studies underwent risk of bias-assessment and data extraction by two review authors independently. We used risk ratio or mean difference to evaluate the treatment effect and meta-analysis for pooled results. The certainty of evidence was assessed using GRADE. We included 31 trials enrolling 3,759 infants. Twenty-five trials were pooled in the comparison delayed cord clamping or cord milking vs. immediate cord clamping or no milking. Increasing placental transfusion resulted in lower mortality during the neonatal period (RR 0.51, 95% CI 0.26 to 1.00; participants = 595; trials = 5; I2 = 0%, moderate certainty of evidence) and during first hospitalization (RR 0.70, 95% CI 0.51, 0.96; 10 RCTs, participants = 2,476, low certainty of evidence). The certainty of evidence was very low for the other primary outcomes of this review. The six remaining trials compared devices to monitor glucose levels (three trials), blood sampling from the umbilical cord or from the placenta vs. blood sampling from the infant (2 trials), and devices to reintroduce the blood after analysis vs. conventional blood sampling (1 trial); the certainty of evidence was rated as very low for all outcomes in these comparisons. Increasing placental transfusion at birth may reduce mortality in very preterm infants; However, extremely limited evidence is available to assess the effects of other interventions to reduce blood loss after birth. In future trials, infants could be randomized following placental transfusion to different blood saving approaches. Trial registration: PROSPERO CRD42020159882.

Impaired Oligodendrocyte Development Following Preterm Birth: Promoting GABAergic Action to Improve Outcomes

Preterm birth is associated with poor long-term neurodevelopmental and behavioral outcomes, even in the absence of obvious brain injury at the time of birth. In particular, behavioral disorders characterized by inattention, social difficulties and anxiety are common among children and adolescents who were born moderately to late preterm (32-37 weeks' gestation). Diffuse deficits in white matter microstructure are thought to play a role in these poor outcomes with evidence suggesting that a failure of oligodendrocytes to mature and myelinate axons is responsible. However, there remains a major knowledge gap over the mechanisms by which preterm birth interrupts normal oligodendrocyte development. In utero neurodevelopment occurs in an inhibitory-dominant environment due to the action of placentally derived neurosteroids on the GABA_A receptor, thus promoting GABAergic inhibitory activity and maintaining the fetal behavioral state. Following preterm birth, and the subsequent premature exposure to the ex utero environment, this action of neurosteroids on GABA_A receptors is greatly reduced. Coinciding with a reduction in GABAergic inhibition, the preterm neonatal brain is also exposed to ex utero environmental insults such as periods of hypoxia and excessive glucocorticoid concentrations. Together, these insults may increase levels of the excitatory neurotransmitter glutamate in the developing brain and result in a shift in the balance of inhibitory: excitatory activity toward excitatory. This review will outline the normal development of oligodendrocytes, how it is disrupted under excitation-dominated conditions and highlight how shifting the balance back toward an inhibitory-dominated environment may improve outcomes.

Continuous glucose monitoring for the prevention of morbidity and mortality in preterm infants

BACKGROUND

Preterm infants are susceptible to hyperglycemia and hypoglycemia, conditions which may lead to adverse neurodevelopment. The use of continuous glucose monitoring devices (CGM) might help keeping glucose levels in the normal range, and reduce the need for blood sampling. However, the use of CGM might be associated with harms in the preterm infant.

OBJECTIVES

Objective one: to assess the benefits and harms of CGM alone versus standard method of glycemic measure in preterm infants. Objective two: to assess the benefits and harms of CGM with automated algorithm versus standard method of glycemic measure in preterm infants. Objective three: to assess the benefits and harms of CGM with automated algorithm versus CGM without automated algorithm in preterm infants.

SEARCH METHODS

We adopted the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 9), in the Cochrane Library; MEDLINE via PubMed (1966 to 25 September 2020); Embase (1980 to 25 September 2020); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 25 September 2020). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomized controlled trials and quasi-randomized trials.

SELECTION CRITERIA

Randomized controlled trials (RCTs) and quasi-RCTs in preterm infants comparing: 1) the use of CGM versus intermittent modalities to measure glycemia (comparison 1); or CGM associated with prespecified interventions to correct hypoglycemia or hyperglycemia versus CGM without such prespecified interventions (comparison 2).

DATA COLLECTION AND ANALYSIS

We assessed the methodological quality of included trials using Cochrane Effective Practice and Organisation of Care Group (EPOC) criteria (assessing randomization, blinding, loss to follow-up, and handling of outcome data). We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data and mean, standard deviation (SD), and mean difference (MD) for continuous data. We used the GRADE approach to assess the certainty of the evidence.

MAIN RESULTS

Four trials enrolling 138 infants met our inclusion criteria. Investigators in three trials (118 infants) compared the use of CGM to intermittent modalities (comparison one); however one of these trials was analyzed separately because CGM was used as a standalone device, without being coupled to a control algorithm like in the other trials. A fourth trial (20 infants) assessed CGM with an automated algorithm versus CGM with a manual algorithm. None of the four included trials reported the neurodevelopmental outcome, i.e. the primary outcome of this review. Within comparison one, the certainty of the evidence on the use of CGM on mortality during hospitalization is very uncertain (typical RR 3.00, 95% CI 0.13 to 70.30; typical RD 0.04, 95% CI -0.06 to 0.14; 50 participants; 1  study; very low certainty). The number of hypoglycemic episodes was reported in two studies with conflicting data. The number of hyperglycemic episodes was reported in one study (typical MD -1.40, 95% CI -2.84 to 0.04; 50 participants; 1 study). The certainty of the evidence was very low for all outcomes because of limitations in study design, and imprecision of estimates.  Three studies are ongoing.

AUTHORS' CONCLUSIONS

There is insufficient evidence to determine if CGM improves preterm infant mortality or morbidities. Long-term outcomes were not reported. Clinical trials are required to determine the most effective CGM and glycemic management regimens in preterm infants before larger studies can be performed to assess the efficacy of CGM  for reducing mortality, morbidity and long-term neurodevelopmental impairments. The absence of CGM labelled for neonatal use is still a major limit in its use as well as the absence of dedicated neonatal devices.

Diagnostic Specificity of Cerebral Magnetic Resonance Imaging for Punctate White Matter Lesion Assessment in a Preterm Sheep Fetus Model

Recent studies, using magnetic resonance imaging (MRI) to assess white matter injury in preterm brains, increasingly recognize punctate white matter lesions (PWML) as the primary lesion type. There are some papers showing the relationship between the size and number of PWML and the prognosis of infants. However, the histopathological features are still unknown. In this study, we experimentally induced periventricular leukomalacia (PVL) in a sheep fetus model, aiming to find whether MRI can visualize necrotic foci (small incipient lesions of PVL) as PWML. Three antenatal insults were employed to induce PVL in preterm fetuses at gestational day 101-117: (i) hypoxia under intrauterine inflammation, (ii) restriction of artificial placental blood flow, and (iii) restriction of artificial placental blood flow after exposure to intrauterine inflammation. MRI was performed 3-5 days after the insults, and standard histological studies of the PVL validated its findings. Of the 89 necrotic foci detected in histological samples from nine fetuses with PVL, 78 were visualized as PWML. Four of the lesions detected as abnormal findings on MRI could not be histologically detected as corresponding abnormal findings. The diagnostic sensitivity and positive predictive values of histologic focal necrosis visualized as PWML were 0.92 and 0.95, respectively. The four lesions were excluded from these analyses. These data suggest that MRI can visualize PVL necrotic foci as PWML 3-5 days after the injury induction. PWML can spontaneously become obscure with time after birth, so their accurate diagnosis in the acute phase can prevent overlooking mild PVL.

Confounding biases in studies on early- versus late-caffeine in preterm infants: a systematic review

BACKGROUND

Caffeine is indicated for the management of apnoea of prematurity and extubation in preterm infants. Early initiation of caffeine administration has increased in the past decades with the purpose of reducing respiratory morbidity. However, there might be harms associated with this approach. This systematic review aims to assess whether early administration of caffeine reduces morbidity and mortality in preterm infants.

METHODS

The methods were published in a preregistered protocol. The literature search was performed in February 2019 with no restrictions for language or publication date. Randomised controlled trials (RCTs) and cohort studies comparing early versus late caffeine administration to infants born before week 34 were included.

RESULTS

Two RCTs and 14 cohort studies were included. All studies but one had a serious/critical overall risk of bias. Few studies reported on long-term or patient-relevant outcomes. No meta-analysis could be performed.

CONCLUSION

Based on the available evidence, no conclusions about the optimal timing of caffeine administration can be drawn. There are inherent methodological problems in the cohort studies. RCTs are needed to answer the question of optimal timing for caffeine administration in neonatal care. Future trials should focus on outcomes relevant to patients and their families and include long-term outcomes.

Stem cell-based interventions for the prevention of morbidity and mortality following hypoxic-ischaemic encephalopathy in newborn infants

BACKGROUND

Hypoxic-ischaemic encephalopathy (HIE) is a leading cause of mortality and long-term neurological sequelae, affecting thousands of children worldwide. Current therapies to treat HIE are limited to cooling. Stem cell-based therapies offer a potential therapeutic approach to repair or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal trials.

OBJECTIVES

To determine the efficacy and safety of stem cell-based interventions for the treatment of hypoxic-ischaemic encephalopathy (HIE) in newborn infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2020, Issue 5), MEDLINE via PubMed (1966 to 8 June 2020), Embase (1980 to 8 June 2020), and CINAHL (1982 to 8 June 2020). We also searched clinical trials databases, conference proceedings, and the reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

Randomised controlled trials, quasi-randomised controlled trials and cluster trials comparing 1) stem cell-based interventions (any type) compared to control (placebo or no treatment); 2) use of mesenchymal stem/stromal cells (MSCs) of type (e.g. number of doses or passages) or source (e.g. autologous versus allogeneic, or bone marrow versus cord) versus MSCs of other type or source; 3) use of stem cell-based interventions other than MSCs of type (e.g. mononuclear cells, oligodendrocyte progenitor cells, neural stem cells, hematopoietic stem cells, and inducible pluripotent stem cells) or source (e.g. autologous versus allogeneic, or bone marrow versus cord) versus stem cell-based interventions other than MSCs of other type or source; or 4) MSCs versus stem cell-based interventions other than MSCs.

DATA COLLECTION AND ANALYSIS

For each of the included trials, two authors independently planned to extract data (e.g. number of participants, birth weight, gestational age, type and source of MSCs or other stem cell-based interventions) and assess the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). The primary outcomes considered in this review are all-cause neonatal mortality, major neurodevelopmental disability, death or major neurodevelopmental disability assessed at 18 to 24 months of age. We planned to use the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Our search strategy yielded 616 references. Two review authors independently assessed all references for inclusion. We did not find any completed studies for inclusion. Fifteen RCTs are currently registered and ongoing. We describe the three studies we excluded.

AUTHORS' CONCLUSIONS

There is currently no evidence from randomised trials that assesses the benefit or harms of stem cell-based interventions for the prevention of morbidity and mortality following hypoxic-ischaemic encephalopathy in newborn infants.

Placental Pathology Findings and the Risk of Intraventricular and Cerebellar Hemorrhage in Preterm Neonates

Placental pathology as a predisposing factor to intraventricular hemorrhage remains a matter of debate, and its contribution to cerebellar hemorrhage development is still largely unexplored. Our study aimed to assess placental and perinatal risk factors for intraventricular and cerebellar hemorrhages in preterm infants. This retrospective cohort study included very low-birth weight infants born at the Gaslini Children's Hospital between January 2012 and October 2016 who underwent brain magnetic resonance with susceptibility-weighted imaging at term-equivalent age and whose placenta was analyzed according to the Amsterdam Placental Workshop Group Consensus Statement. Of the 286 neonates included, 68 (23.8%) had intraventricular hemorrhage (all grades) and 48 (16.8%) had a cerebellar hemorrhage (all grades). After correction for gestational age, chorioamnionitis involving the maternal side of the placenta was found to be an independent risk factor for developing intraventricular hemorrhage, whereas there was no association between maternal and fetal inflammatory response and cerebellar hemorrhage. Among perinatal factors, we found that intraventricular hemorrhage was significantly associated with cerebellar hemorrhage (odds ratio [OR], 8.14), mechanical ventilation within the first 72 h (OR, 2.67), and patent ductus arteriosus requiring treatment (OR, 2.6), whereas cesarean section emerged as a protective factor (OR, 0.26). Inotropic support within 72 h after birth (OR, 5.24) and intraventricular hemorrhage (OR, 6.38) were independent risk factors for cerebellar hemorrhage, whereas higher gestational age was a protective factor (OR, 0.76). Assessing placental pathology may help in understanding mechanisms leading to intraventricular hemorrhage, although its possible role in predicting cerebellar bleeding needs further evaluation.

Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key

With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.

Head midline position for preventing the occurrence or extension of germinal matrix-intraventricular haemorrhage in preterm infants

BACKGROUND

Head position during care may affect cerebral haemodynamics and contribute to the development of germinal matrix-intraventricular haemorrhage (GM-IVH) in very preterm infants. Turning the head toward one side may occlude jugular venous drainage while increasing intracranial pressure and cerebral blood volume. It is suggested that cerebral venous pressure is reduced and hydrostatic brain drainage improved if the infant is cared for in the supine 'head midline' position.

OBJECTIVES

To assess whether head midline position is more effective than other head positions for preventing (or preventing extension) of GM-IVH in very preterm infants (< 32 weeks' gestation at birth).

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 9), MEDLINE via PubMed (1966 to 12 September 2019), Embase (1980 to 12 September 2019), and the Cumulative Index to Nursing and Allied Health Literature (CINAHL; 1982 to 12 September 2019). We searched clinical trials databases, conference proceedings, and reference lists of retrieved articles.

SELECTION CRITERIA

Randomised controlled trials (RCTs) comparing caring for very preterm infants in a supine head midline position versus a prone or lateral decubitus position, or undertaking a strategy of regular position change, or having no prespecified position. We included trials enrolling infants with existing GM-IVH and planned to assess extension of haemorrhage in a subgroup of infants. We planned to analyse horizontal (flat) versus head elevated positions separately for all body positions.

DATA COLLECTION AND ANALYSIS

We used standard methods of Cochrane Neonatal. For each of the included trials, two review authors independently extracted data and assessed risk of bias. The primary outcomes were GM-IVH, severe IVH, and neonatal death. We evaluated treatment effects using a fixed-effect model with risk ratio (RR) for categorical data; and mean, standard deviation (SD), and mean difference (MD) for continuous data. We used the GRADE approach to assess the certainty of evidence.

MAIN RESULTS

Three RCTs, with a total of 290 infants (either < 30 weeks' gestational age or < 1000 g body weight), met the inclusion criteria. Two trials compared supine midline head position versus head rotated 90° with the cot flat. One trial compared supine midline head position versus head rotated 90° with the bed tilted at 30°. We found no trials that compared supine versus prone midline head position. Meta-analysis of three trials (290 infants) did not show an effect on rates of GM-IVH (RR 1.11, 95% confidence interval (CI) 0.78 to 1.56; I² = 0%) and severe IVH (RR 0.71, 95% CI 0.37 to 1.33; I² = 0%). Neonatal mortality (RR 0.49, 95% CI 0.25 to 0.93; I² = 0%; RD -0.09, 95% CI -0.16 to -0.01) and mortality until hospital discharge (typical RR 0.50, 95% CI 0.28 to 0.90; I² = 0%; RD -0.10, 95% CI -0.18 to -0.02) were lower in the supine midline head position. The certainty of the evidence was very low for all outcomes because of limitations in study design and imprecision of estimates. We identified one ongoing study.

AUTHORS' CONCLUSIONS

We found few trial data on the effects of head midline position on GM-IVH in very preterm infants. Although meta-analyses suggest that mortality might be reduced, the certainty of the evidence is very low and it is unclear whether any effect is due to cot tilting (a co-intervention in one trial). Further high-quality RCTs would be needed to resolve this uncertainty.

Correlation of lateral ventricular size and deep gray matter volume in MRI at term equivalent age with neurodevelopmental outcome at a corrected age of 24 months and with handedness in preterm infants

The aim of this study was to correlate ventricular size and volumes of deep gray matter (DGM) in MRI at term equivalent age (TEA) with outcome at a corrected age of 24 months in preterm infants and with handedness. Seventy-three infants born before 32 weeks of gestation or with birth weight < 1500 g  were included in this retrospective analysis and measurement of lateral ventricles, and DGM was performed on MRI scans. The left lateral ventricle was significantly larger than the right lateral ventricle (p = 0.001). There was no correlation between volumes of the right and left ventricles and the DGM volume (p = 0.207 and p = 0.597, respectively), nor with the head circumference at TEA (p = 0.177 and p = 0.976, respectively). The total volume of both lateral ventricles did not correlate with Mental Develomental Index (MDI, p = 0.336) or Psychomotor Developmental Index (PDI, p = 0.650) score (Bayley Scales of Infant Development, BSID II). However, a correlation of total DGM volume with birth weight (p = 0.0001; r = 0.437), head circumference at TEA (p < 0.0001; r = 0.640), MDI (p = 0.029; r = 0.310), and PDI (p = 0.002; r = 0.456) was observed. No significant difference between right- and left-handed infants was seen in relation to volumes of both lateral ventricles and of DGM.Conclusion: DGM volume at TEA was significantly associated with the outcome at a corrected age of 24 months. Handedness did not correlate with DGM or lateral ventricle size.What is Known:• White matter injury as well as altered development of deep gray matter is associated with neurodevelopmental disability in preterm infants.• No study analyzed the association between deep gray matter volume or volumes of lateral ventricle and handedness in former preterm infants so far.What is New:• Volume of deep gray matter, but not lateral ventricular size was significantly associated with outcome at a corrected age of 24 months in preterm infants.• There was no correlation of handedness with volumes of lateral ventricular size or with deep gray matter volumes.

Neuroimaging findings in newborns with congenital heart disease prior to surgery: an observational study

OBJECTIVES

Neurodevelopmental impairment has become the most important comorbidity in infants with congenital heart disease (CHD). We aimed to (1) investigate the burden of brain lesions in infants with CHD prior to surgery and (2) explore clinical factors associated with injury.

STUDY DESIGN

Prospective observational study.

SETTING

Single centre UK tertiary neonatal intensive care unit.

PATIENTS

70 newborn infants with critical or serious CHD underwent brain MRI prior to surgery.

MAIN OUTCOME MEASURES

Prevalence of cerebral injury including arterial ischaemic strokes (AIS), white matter injury (WMI) and intracranial haemorrhage.

RESULTS

Brain lesions were observed in 39% of subjects (95% CI 28% to 50%). WMI was identified in 33% (95% CI 23% to 45%), subdural haemorrhage without mass effect in 33% (95% CI 23% to 45%), cerebellar haemorrhage in 9% (95% CI 4% to 18%) and AIS in 4% (95% CI 1.5% to 12%). WMI was distributed widely throughout the brain, particularly involving the frontal white matter, optic radiations and corona radiata. WMI exhibited restricted diffusion in 48% of cases. AIS was only observed in infants with transposition of the great arteries (TGA) who had previously undergone balloon atrial septostomy (BAS). AIS was identified in 23% (95% CI 8% to 50%) of infants with TGA who underwent BAS, compared with 0% (95% CI 0% to 20%) who did not.

CONCLUSIONS

Cerebral injury in newborns with CHD prior to surgery is common.

Stem cell-based interventions for the prevention and treatment of germinal matrix-intraventricular haemorrhage in preterm infants

BACKGROUND

Germinal matrix-intraventricular haemorrhage (GMH-IVH) remains a substantial issue in neonatal intensive care units worldwide. Current therapies to prevent or treat GMH-IVH are limited. Stem cell-based therapies offer a potential therapeutic approach to repair, restore, and/or regenerate injured brain tissue. These preclinical findings have now culminated in ongoing human neonatal studies.

OBJECTIVES

To determine the benefits and harms of stem cell-based interventions for prevention or treatment of germinal matrix-intraventricular haemorrhage (GM-IVH) in preterm infants.

SEARCH METHODS

We used the standard search strategy of Cochrane Neonatal to search the Cochrane Central Register of Controlled Trials (CENTRAL; 2019, Issue 1), in the Cochrane Library; MEDLINE via PubMed (1966 to 7 January 2019); Embase (1980 to 7 January 2019); and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) (1982 to 7 January 2019). We also searched clinical trials databases, conference proceedings, and reference lists of retrieved articles for randomised controlled trials and quasi-randomised trials.

SELECTION CRITERIA

We attempted to identify randomised controlled trials, quasi-randomised controlled trials, and cluster trials comparing (1) stem cell-based interventions versus control; (2) mesenchymal stromal cells (MSCs) of type or source versus MSCs of other type or source; (3) stem cell-based interventions other than MSCs of type or source versus stem cell-based interventions other than MSCs of other type or source; or (4) MSCs versus stem cell-based interventions other than MSCs. For prevention studies, we included extremely preterm infants (less than 28 weeks' gestation), 24 hours of age or less, without ultrasound diagnosis of GM-IVH; for treatment studies, we included preterm infants (less than 37 weeks' gestation), of any postnatal age, with ultrasound diagnosis of GM-IVH.

DATA COLLECTION AND ANALYSIS

For each of the included trials, two review authors independently planned to extract data (e.g. number of participants, birth weight, gestational age, type and source of MSCs, other stem cell-based interventions) and assess the risk of bias (e.g. adequacy of randomisation, blinding, completeness of follow-up). Primary outcomes considered in this review are all-cause neonatal mortality, major neurodevelopmental disability, GM-IVH, and extension of pre-existing non-severe GM-IVH. We planned to use the GRADE approach to assess the quality of evidence.

MAIN RESULTS

Our search strategy yielded 769 references. We did not find any completed studies for inclusion. One randomised controlled trial is currently registered and ongoing. Five phase 1 trials are described in the excluded studies.

AUTHORS' CONCLUSIONS

Currently no evidence is available to show the benefits or harms of stem cell-based interventions for treatment or prevention of GM-IVH in preterm infants.

Punctate white matter lesions of preterm infants: Risk factor analysis

AIM

Punctate white matter lesions (PWML) are frequently detected in preterm infants undergoing brain MRI at term equivalent age (TEA). The aims of this study were to assess prevalence of PWML and to identify risk factors for PWML in VLBW infants.

METHODS

Brain MRI scans obtained at TEA and clinical charts of a consecutive sample of very low birth weight (VLBW) infants admitted to Gaslini Children's Hospital NICU between 2012 and 2016 were retrospectively analyzed. MRI protocol included Susceptibility Weighted Imaging (SWI) sequence in order to identify hemosiderin depositions as a result of previous microbleeds. PWML were classified according to their number (≤6 lesions and >6 lesions) and signal characteristics (SWI+ lesions and SWI- lesions). Univariate and multivariable analysis were performed in order to identify risk factors for PWML (as a whole) and for each subgroup of PWML.

RESULTS

321 VLBW infants were included. PWML were identified in 61 subjects (19%), 26 of whom (8% of the study population) had more than 6 lesions. Risk factors for PWML (as a whole) were higher birth weight (OR = 1.001; p = 0.04) and absent or incomplete antenatal steroid course (OR = 2.13; p = 0.02). Risk factors for >6 PWML were need for intubation (OR = 11.9; p = 0.003) and higher Apgar score at 5 min (OR = 1.8; p = 0.02). Presence of GMH-IVH was the only identified risk factor for SWI + lesions.

CONCLUSIONS

Our results confirm the high prevalence of PWML among VLBW infants. Differentiation between SWI+ and SWI- lesions is crucial as they have different risk factors and may likely represent two different entities.

Automated quantitative evaluation of brain MRI may be more accurate for discriminating preterm born adults

OBJECTIVE

To investigate the structural brain abnormalities and their diagnostic accuracy through qualitative and quantitative analysis in term born and very preterm birth or with very low birth weight (VP/VLBW) adults.

METHODS

We analyzed 3-T MRIs acquired in 2011-2013 from 67 adults (27 term born controls, mean age 26.4 years, 8 females; 40 VP/VLBWs, mean age 26.6 years, 16 females). We compared automatic segmentations of the white matter, deep gray matter and cortical gray matter, manual corpus callosum measurements and visual ratings of the ventricles and white matter with t tests, logistic regression, and receiver operator characteristic (ROC) curves.

RESULTS

Automatic segmentation correctly classified 84% of cases; visual ratings correctly classified 63%. Quantitative volumetry based on automatic segmentation revealed higher ventricular volume, lower posterior corpus callosum, and deep gray matter volumes in VP/VLBW subjects compared to controls (p < 0.01). Visual rating and manual measurement revealed a thinner corpus callosum in VP/VLBW adults (p = 0.04) and deformed lateral ventricles (p = 0.03) and tendency towards more "dirty" white matter (p = 0.06). Automatic/manual measures combined with visual ratings correctly classified 87% of cases. Stepwise logistic regression identified three independent features that correctly classify 81% of cases: ventricular volume, deep gray matter volume, and white matter aspect.

CONCLUSION

Enlarged and deformed lateral ventricles, thinner corpus callosum, and "dirty" white matter are prevalent in preterm born adults. Their visual evaluation has low diagnostic accuracy. Automatic volume quantification is more accurate but time consuming. It may be useful to ask for prematurity before initiating further diagnostics in subjects with these alterations.

KEY POINTS

• Our study confirms prior reports showing that structural brain abnormalities related to preterm birth persist into adulthood. • In the clinical practice, if large and deformed lateral ventricles, small and thin corpus callosum, and "dirty" white matter are visible on MRI, ask for prematurity before considering other diagnoses. • Although prevalent, visual findings have low accuracy; adding automatic segmentation of lateral ventricles and deep gray matter nuclei improves the diagnostic accuracy.

Neuroprotection of the preterm brain

Despite notable advances in the care and survival of preterm infants, a significant proportion of preterm neonates will have life-long cognitive, behavioral, and motor deficits, and robustly effective neuroprotective strategies are still missing. These therapies must target the pathophysiologic mechanisms observed in contemporaneous infants and rely on modern epidemiology, imaging, and experimental models and assessment techniques. Two drugs, magnesium sulfate and caffeine, are already in use in several units, and although their targets are apnea of prematurity and myometrial contractility (respectively), they do offer improved odds of positive outcomes. Nevertheless, these drugs have limited efficacy, and NICU-to-NICU administration varies greatly. As such, there is an obvious need for additional specific neurotherapeutic strategies to further enhance the outcome of this very fragile population of neonates. The chapter reviews these issues, highlights bottlenecks that need to be solved for meaningful progress in the field, and proposes future innovative avenues for intervention, including delayed interventions.

Total and sn-2 fatty acid profile of breast milk from women delivering preterm infants under the influence of maternal characteristics

Data on the total fatty acid (FA) profile and position-specific triacylglycerides (TAGs) in preterm infants' maternal milk are essential for establishing the recommended requirement of FA in preterm infants in China. We aimed to determine the composition and positional distribution of FAs in preterm infants' maternal milk in China and further investigate the effect of maternal background on the FA composition. Breast milk samples (4, 11, 30, 60, and 90 (all ±3) days post-partum) were collected from 59 healthy women delivering preterm infants. The total and sn-2 milk FA composition was determined using gas chromatography. The multivariate statistical analysis showed significant differences in the FA profiles of milk with different lactation times, gestational ages and maternal ages. In particular, the content of linoleic and linolenic acid (ALA) was much higher, whereas the content of docosahexaenoic (DHA) and arachidonic acid were lower in the preterm milk from the Wuxi district than that from America and countries in Europe. The content of sn-2 polyunsaturated FAs (ALA: p = 0.013 and DHA: p = 0.003) were lower in the preterm colostrum from women aged over 30 years. Overall, these results suggest that the European and American standards of preterm formula may not be suitable for Chinese preterm infants, and polyunsaturated FA fortification in the maternal diet or preterm formula is needed for women with advanced age.

Perioperative neonatal brain injury is associated with worse school-age neurodevelopment in children with critical congenital heart disease

AIM

To assess the impact of perioperative neonatal brain injury and brain volumes on neurodevelopment throughout school-age children with critical congenital heart disease (CHD).

METHOD

Thirty-four survivors of neonatal cardiac surgery (seven females, 27 males) were included. Neonatal preoperative and postoperative cerebral magnetic resonance imaging was performed and neurodevelopment was assessed at 24 months (SD 0.7, n=32, using Bayley Score of Infant and Toddler Development, Child Behavior Checklist) and 6 years (mean age 5y 11mo; SD 0.3, n=30, using Movement Assessment Battery for Children, Wechsler Preschool and Primary Scale of Intelligence, Child Behavior Checklist, Teacher Report Form). Brain injury, brain volumes, and cortical measures were related to outcome with adjustment for maternal educational level.

RESULTS

Two-year cognitive score and 6-year Full-scale IQ were poorer in children with neonatal white matter injury (n=21, all p<0.05), with higher teacher-reported attention problems (p=0.03). Five of six children with involvement of the posterior limb of the internal capsule showed motor problems (p=0.03). Children with a below-average Fulll-scale IQ (<85, n=9) showed smaller volumes of basal ganglia thalami (-8%, p=0.03) and brain stem (-7%, p=0.03).

INTERPRETATION

Our findings provide evidence of unfavourable outcome in school-age children with critical CHD who acquire perioperative neonatal brain injury.

WHAT THIS PAPER ADDS

This paper extends knowledge about neonatal brain injury and long-term outcome in congenital heart disease. Children with white matter injury show lower IQ and more attention problems at school age. Injury of the posterior limb of the internal capsule increases the risk of motor problems. This study provides evidence for worse outcomes in neonates acquiring brain injury around cardiac surgery.

Oxidative Stress as a Primary Risk Factor for Brain Damage in Preterm Newborns

The risk of oxidative stress is high in preterm newborns. Room air exposure of an organism primed to develop in a hypoxic environment, lacking antioxidant defenses, and subjected to hyperoxia, hypoxia, and ischemia challenges the newborn with oxidative stress production. Free radicals can be generated by a multitude of other mechanisms, such as glutamate excitotoxicity, excess free iron, inflammation, and immune reactions. Free radical-induced damage caused by oxidative stress appears to be the major candidate for the pathogenesis of most of the complications of prematurity, brain being especially at risk, with short to long-term consequences. We review the role of free radical oxidative damage to the newborn brain and propose a mechanism of oxidative injury, taking into consideration the particular maturation-dependent vulnerability of the oligodendrocyte precursors. Prompted by our observation of an increase in plasma Adenosine concentrations significantly associated with brain white matter lesions in some premature infants, we discuss a possible bioenergetics hypothesis, correlated to the oxidative challenge of the premature infant. We aim at explaining both the oxidative stress generation and the mechanism promoting the myelination disturbances. Being white matter abnormalities among the most common lesions of prematurity, the use of Adenosine as a biomarker of brain damage appears promising in order to design neuroprotective strategies.

Relationship between brain function (aEEG) and brain structure (MRI) and their predictive value for neurodevelopmental outcome of preterm infants

To improve the prediction of neurodevelopmental outcome in very preterm infants, this study used the combination of amplitude-integrated electroencephalography (aEEG) within the first 72 h of life and cranial magnetic resonance imaging (MRI) at term equivalent age. A single-center cohort of 38 infants born before 32 weeks of gestation was subjected to both investigations. Structural measurements were performed on MRI. Multiple regression analysis was used to identify independent factors including functional and structural brain measurements associated with outcome at a corrected age of 24 months. aEEG parameters significantly correlated with MRI measurements. Reduced deep gray matter volume was associated with low Burdjalov Score on day 3 (p < 0.0001) and day 1-3 (p = 0.0012). The biparietal width and the transcerebellar diameter were related to Burdjalov Score on day 1 (p = 0.0111; p = 0.0002). The final multiple regression analysis revealed independent predictors of neurodevelopmental outcome: intraventricular hemorrhage (p = 0.0060) and interhemispheric distance (p = 0.0052) for mental developmental index; Burdjalov Score day 1 (p = 0.0201) and interhemispheric distance (p = 0.0142) for psychomotor developmental index.

CONCLUSION

Functional aEEG parameters were associated with altered brain maturation on MRI. The combination of aEEG and MRI contributes to the prediction of outcome at 24 months. What is Known: • Prematurity remains a risk factor for impaired neurodevelopment. • aEEG is used to measure brain activity in preterm infants and cranial MRI is performed to identify structural gray and white matter abnormalities with impact on neurodevelopmental outcome. What is New: • aEEG parameters observed within the first 72 h of life were associated with altered deep gray matter volumes, biparietal width, and transcerebellar diameter at term equivalent age. • The combination of aEEG and MRI contributes to the prediction of neurodevelopmental outcome at 2 years of corrected age in very preterm infants.

Neonatal erythropoietin mitigates impaired gait, social interaction and diffusion tensor imaging abnormalities in a rat model of prenatal brain injury

Children who are born preterm are at risk for encephalopathy of prematurity, a leading cause of cerebral palsy, cognitive delay and behavioral disorders. Current interventions are limited and none have been shown to reverse cognitive and behavioral impairments, a primary determinant of poor quality of life for these children. Moreover, the mechanisms of perinatal brain injury that result in functional deficits and imaging abnormalities in the mature brain are poorly defined, limiting the potential to target interventions to those who may benefit most. To determine whether impairments are reversible after a prenatal insult, we investigated a spectrum of functional deficits and diffusion tensor imaging (DTI) abnormalities in young adult animals. We hypothesized that prenatal transient systemic hypoxia-ischemia (TSHI) would induce multiple functional deficits concomitant with reduced microstructural white and gray matter integrity, and tested whether these abnormalities could be ameliorated using postnatal erythropoietin (EPO), an emerging neurorestorative intervention. On embryonic day 18 uterine arteries were transiently occluded for 60min via laparotomy. Shams underwent anesthesia and laparotomy for 60min. Pups were born and TSHI pups were randomized to receive EPO or vehicle via intraperitoneal injection on postnatal days 1 to 5. Gait, social interaction, olfaction and open field testing was performed from postnatal day 25-35 before brains underwent ex vivo DTI to measure fractional anisotropy, axial diffusivity and radial diffusivity. Prenatal TSHI injury causes hyperactivity, impaired gait and poor social interaction in young adult rats that mimic the spectrum of deficits observed in children born preterm. Collectively, these data show for the first time in a model of encephalopathy of prematurity that postnatal EPO treatment mitigates impairments in social interaction, in addition to gait deficits. EPO also normalizes TSHI-induced microstructural abnormalities in fractional anisotropy and radial diffusivity in multiple regions, consistent with improved structural integrity and recovery of myelination. Taken together, these results show behavioral and memory deficits from perinatal brain injury are reversible. Furthermore, resolution of DTI abnormalities may predict responsiveness to emerging interventions, and serve as a biomarker of CNS injury and recovery.