Clinical neuroimaging in the preterm infant: Diagnosis and prognosis

Neurodevelopmental outcome in preterm infants with intraventricular hemorrhages: the potential of quantitative brainstem MRI

OBJECTIVES

This retrospective study aimed to identify quantitative magnetic resonance imaging markers in the brainstem of preterm neonates with intraventricular hemorrhages. It delves into the intricate associations between quantitative brainstem magnetic resonance imaging metrics and neurodevelopmental outcomes in preterm infants with intraventricular hemorrhage, aiming to elucidate potential relationships and their clinical implications.

MATERIALS AND METHODS

Neuroimaging was performed on preterm neonates with intraventricular hemorrhage using a multi-dynamic multi-echo sequence to determine T1 relaxation time, T2 relaxation time, and proton density in specific brainstem regions. Neonatal outcome scores were collected using the Bayley Scales of Infant and Toddler Development. Statistical analysis aimed to explore potential correlations between magnetic resonance imaging metrics and neurodevelopmental outcomes.

RESULTS

Sixty preterm neonates (mean gestational age at birth 26.26 ± 2.69 wk; n = 24 [40%] females) were included. The T2 relaxation time of the midbrain exhibited significant positive correlations with cognitive (r = 0.538, P < 0.0001, Pearson's correlation), motor (r = 0.530, P < 0.0001), and language (r = 0.449, P = 0.0008) composite scores at 1 yr of age.

CONCLUSION

Quantitative magnetic resonance imaging can provide valuable insights into neurodevelopmental outcomes after intraventricular hemorrhage, potentially aiding in identifying at-risk neonates. Multi-dynamic multi-echo sequence sequences hold promise as an adjunct to conventional sequences, enhancing the sensitivity of neonatal magnetic resonance neuroimaging and supporting clinical decision-making for these vulnerable patients.

A Multiplanar Radiomics Model Based on Cranial Ultrasound to Predict the White Matter Injury in Premature Infants and an Analysis of its Correlation With Neurodevelopment

OBJECTIVES

To develop and evaluate a multiplanar radiomics model based on cranial ultrasound (CUS) to predict white matter injury (WMI) in premature infants and explore its correlation with neurodevelopment.

METHODS

We retrospectively reviewed 267 premature infants. The radiomics features were extracted from five standard sections of CUS. The Spearman's correlation coefficient combined with the least absolute shrinkage and selection operator (LASSO) was applied to select features and build radiomics signature, and a multiplanar radiomics model was constructed based on the radiomics signature of five planes. The performance of the model was evaluated using the area under the receiver operating characteristic curve (AUC). Infants with WMI were re-examined by ultrasound at 2 and 4 weeks after birth, and the recovery degree of WMI was evaluated using multiplanar radiomics. The relationship between WMI and the recovery degree and neurodevelopment was analyzed.

RESULTS

The AUC of the multiplanar radiomics in the training and validation sets were 0.94 and 0.91, respectively. The neurodevelopmental function scores in infants with WMI were significantly lower than those in healthy preterm infants and full-term newborns (P < .001). There were statistically significant differences in the neurodevelopmental function scores of infants between the 2- and 4-week lesion disappearance and 4-week lesion persistence (P < .001).

CONCLUSIONS

The multiplanar radiomics model showed a good performance in predicting the WMI of premature infants. It can not only provide objective and accurate results but also dynamically monitor the degree of recovery of WMI to predict the prognosis of premature infants.

Evidence of brain injury in fetuses of mothers with preterm labor with intact membranes and preterm premature rupture of membranes

BACKGROUND

Brain injury and poor neurodevelopment have been consistently reported in infants and adults born before term. These changes occur, at least in part, prenatally and are associated with intra-amniotic inflammation. The pattern of brain changes has been partially documented by magnetic resonance imaging but not by neurosonography along with amniotic fluid brain injury biomarkers.

OBJECTIVE

This study aimed to evaluate the prenatal features of brain remodeling and injury in fetuses from patients with preterm labor with intact membranes or preterm premature rupture of membranes and to investigate the potential influence of intra-amniotic inflammation as a risk mediator.

STUDY DESIGN

In this prospective cohort study, fetal brain remodeling and injury were evaluated using neurosonography and amniocentesis in singleton pregnant patients with preterm labor with intact membranes or preterm premature rupture of membranes between 24.0 and 34.0 weeks of gestation, with (n=41) and without (n=54) intra-amniotic inflammation. The controls for neurosonography were outpatient pregnant patients without preterm labor or preterm premature rupture of membranes matched 2:1 by gestational age at ultrasound. Amniotic fluid controls were patients with an amniocentesis performed for indications other than preterm labor or preterm premature rupture of membranes without brain or genetic defects whose amniotic fluid was collected in our biobank for research purposes matched by gestational age at amniocentesis. The group with intra-amniotic inflammation included those with intra-amniotic infection (microbial invasion of the amniotic cavity and intra-amniotic inflammation) and those with sterile inflammation. Microbial invasion of the amniotic cavity was defined as a positive amniotic fluid culture and/or positive 16S ribosomal RNA gene. Inflammation was defined by amniotic fluid interleukin 6 concentrations of >13.4 ng/mL in preterm labor and >1.43 ng/mL in preterm premature rupture of membranes. Neurosonography included the evaluation of brain structure biometric parameters and cortical development. Neuron-specific enolase, protein S100B, and glial fibrillary acidic protein were selected as amniotic fluid brain injury biomarkers. Data were adjusted for cephalic biometrics, fetal growth percentile, fetal sex, noncephalic presentation, and preterm premature rupture of membranes at admission.

RESULTS

Fetuses from mothers with preterm labor with intact membranes or preterm premature rupture of membranes showed signs of brain remodeling and injury. First, they had a smaller cerebellum. Thus, in the intra-amniotic inflammation, non-intra-amniotic inflammation, and control groups, the transcerebellar diameter measurements were 32.7 mm (interquartile range, 29.8-37.6), 35.3 mm (interquartile range, 31.2-39.6), and 35.0 mm (interquartile range, 31.3-38.3), respectively (P=.019), and the vermian height measurements were 16.9 mm (interquartile range, 15.5-19.6), 17.2 mm (interquartile range, 16.0-18.9), and 17.1 mm (interquartile range, 15.7-19.0), respectively (P=.041). Second, they presented a lower corpus callosum area (0.72 mm2 [interquartile range, 0.59-0.81], 0.71 mm2 [interquartile range, 0.63-0.82], and 0.78 mm2 [interquartile range, 0.71-0.91], respectively; P=.006). Third, they showed delayed cortical maturation (the Sylvian fissure depth-to-biparietal diameter ratios were 0.14 [interquartile range, 0.12-0.16], 0.14 [interquartile range, 0.13-0.16], and 0.16 [interquartile range, 0.15-0.17], respectively [P<.001], and the right parieto-occipital sulci depth ratios were 0.09 [interquartile range, 0.07-0.12], 0.11 [interquartile range, 0.09-0.14], and 0.11 [interquartile range, 0.09-0.14], respectively [P=.012]). Finally, regarding amniotic fluid brain injury biomarkers, fetuses from mothers with preterm labor with intact membranes or preterm premature rupture of membranes had higher concentrations of neuron-specific enolase (11,804.6 pg/mL [interquartile range, 6213.4-21,098.8], 8397.7 pg/mL [interquartile range, 3682.1-17,398.3], and 2393.7 pg/mL [interquartile range, 1717.1-3209.3], respectively; P<.001), protein S100B (2030.6 pg/mL [interquartile range, 993.0-4883.5], 1070.3 pg/mL [interquartile range, 365.1-1463.2], and 74.8 pg/mL [interquartile range, 44.7-93.7], respectively; P<.001), and glial fibrillary acidic protein (1.01 ng/mL [interquartile range, 0.54-3.88], 0.965 ng/mL [interquartile range, 0.59-2.07], and 0.24 mg/mL [interquartile range, 0.20-0.28], respectively; P=.002).

CONCLUSION

Fetuses with preterm labor with intact membranes or preterm premature rupture of membranes had prenatal signs of brain remodeling and injury at the time of clinical presentation. These changes were more pronounced in fetuses with intra-amniotic inflammation.

Serum Neuron-Specific Enolase as a Biomarker of Neonatal Brain Injury-New Perspectives for the Identification of Preterm Neonates at High Risk for Severe Intraventricular Hemorrhage

Neonatal brain injury (NBI) is a critical condition for preterm neonates with potential long-term adverse neurodevelopmental outcomes. This prospective longitudinal case-control study aimed at investigating the levels and prognostic value of serum neuron-specific enolase (NSE) during the first 3 days of life in preterm neonates (<34 weeks) that later developed brain injury in the form of either periventricular leukomalacia (PVL) or intraventricular hemorrhage (IVH) during their hospitalization. Participants were recruited from one neonatal intensive care unit, and on the basis of birth weight and gestational age, we matched each case (n = 29) with a neonate who had a normal head ultrasound scan (n = 29). We report that serum NSE levels during the first three days of life do not differ significantly between control and preterm neonates with NBI. Nevertheless, subgroup analysis revealed that neonates with IVH had significantly higher concentrations of serum NSE in comparison to controls and neonates with PVL on the third day of life (p = 0.014 and p = 0.033, respectively). The same pattern on the levels of NSE on the third day of life was also observed between (a) neonates with IVH and all other neonates (PVL and control; p = 0.003), (b) neonates with II-IV degree IVH and all other neonates (p = 0.003), and (c) between control and the five (n = 5) neonates that died from the case group (p = 0.023). We conclude that NSE could be an effective and useful biomarker on the third day of life for the identification of preterm neonates at high risk of developing severe forms of IVH.

Differences in the amplitude of low-frequency fluctuations of spontaneous brain activity between preterm and term infants

Objectives

To date, the majority of research on resting-state functional magnetic resonance imaging (rs-fMRI) in the developing brain has primarily centered on adolescents and adults, leaving a gap in understanding variations in spontaneous brain activity at rest in preterm infants. This study aimed to uncover and comprehend the distinctions in spontaneous brain activity between preterm and term infants, with the goal of establishing a foundation for assessing the condition of preterm infants.

Methods

In this study, 14 term infants and 15 preterm infants with equivalent gestational age were carefully chosen from the neonatal unit of Anhui Provincial Children's Hospital. The amplitude of low-frequency fluctuations (ALFF) intensity was assessed using resting-state functional magnetic resonance imaging (rs-fMRI) to examine brain activity in both groups. Subsequently, the differences between the term and preterm infants were statistically analyzed using a two-sample t-test. A p-value of <0.05, corrected for the REST Gaussian Random Fields, was deemed to be statistically significant.

Results

In comparison to the term infant group, the preterm infant group exhibited a significant increase in the ALFF value in the left precuneus, left frontal superior orbital gyrus, and left calcarine cortex.

Conclusion

Significant variances in spontaneous brain activity have been observed in various regions between term infants and preterm infants of equivalent gestational age. These variations could potentially impact the emotional and cognitive development of preterm infants in the long term.

Association of aEEG and brain injury severity on MRI at term-equivalent age in preterm infants

AIM

Measures to detect and monitor brain injury in preterm infants are amplitude-integrated electroencephalography (aEEG) and magnetic resonance imaging (MRI). To investigate the association between aEEG and MRI in a large cohort of preterm infants. Five hundred and twenty-three preterm infants were included in the study.

METHODS

AEEG was interpreted for the total maturation score (TMS) according to Burdjalov. Cerebral MRI was evaluated using a validated scoring system by Kidokoro.

RESULTS

One hundred and forty-six infants (27.9%) showed some form of brain injury, with 111 infants (21.2%) showing mild injury and 35 (6.7%) showing severe injury. TMS were significantly higher in infants without injury compared to severe injury. When comparing infants with isolated intraventricular haemorrhage  to infants without brain injury, TMS were significantly lower.

CONCLUSION

Prediction of adverse outcome is an important aspect of neonatal care. The combination of diagnostic measures evaluating brain injury might enhance our abilities in neonatal care to provide accurate information about later outcome. Early aEEG is predictive for the severity of brain injury detected by MRI at term-equivalent age. Whether aEEG is also predictive for neurodevelopmental outcome needs to be further investigated in relation to the various patterns of preterm brain injury.

Overview of the Current Knowledge and Conventional MRI Characteristics of Peri- and Para-Vascular Spaces

Brain spaces around (perivascular spaces) and alongside (paravascular or Virchow-Robin spaces) vessels have gained significant attention in recent years due to the advancements of in vivo imaging tools and to their crucial role in maintaining brain health, contributing to the anatomic foundation of the glymphatic system. In fact, it is widely accepted that peri- and para-vascular spaces function as waste clearance pathways for the brain for materials such as ß-amyloid by allowing exchange between cerebrospinal fluid and interstitial fluid. Visible brain spaces on magnetic resonance imaging are often a normal finding, but they have also been associated with a wide range of neurological and systemic conditions, suggesting their potential as early indicators of intracranial pressure and neurofluid imbalance. Nonetheless, several aspects of these spaces are still controversial. This article offers an overview of the current knowledge and magnetic resonance imaging characteristics of peri- and para-vascular spaces, which can help in daily clinical practice image description and interpretation. This paper is organized into different sections, including the microscopic anatomy of peri- and para-vascular spaces, their associations with pathological and physiological events, and their differential diagnosis.

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.

A Review of the Occurrence of Intraventricular Hemorrhage in Preterm Newborns and its Future Neurodevelopmental Consequences

Intraventricular hemorrhage (IVH) is a type of bleeding that occurs through the germinal matrix and comes through the ependymal cells into the ventricular cavity. It is mostly seen in preterm neonates but can also be seen sometimes in term neonates. Various factors predispose to preterm delivery; it can be spontaneous or medically induced. Spontaneous IVH occurs in cases of intrauterine infections in the mother, and it can be induced in cases of medical emergencies such as preeclampsia and eclampsia. The brain of a preterm newborn is not fully developed as it does not have pericytes and proteins, so it can bleed very quickly, which can cause IVH. Also, the vessels supplying the germinal matrix are immature and highly vascularized. IVH has four grades based on findings detected on cranial ultrasound and MRI. Management includes medical and surgical management; medical management includes phenobarbitone used for seizures and prophylaxis. Surgical management includes drainage, irrigation, and fibrinolytic therapy (DRIFT), and neuro-endoscopic lavage. IVH causes various short-term and long-term neurodevelopmental consequences. Long-term complications include cerebral palsy and intellectual disability, which hamper the life of the child. It mainly presents with seizures, flaccidity, decerebrate posture, etc. Various preventive measures can be taken to tackle IVH in newborns. First of all, preterm delivery should be avoided, and intrauterine infections in mothers should be treated. The administration of corticosteroids should be done for all preterm deliveries as it helps in the maturation of organs. The administration of magnesium sulfate should be done as it is neuroprotective and reduces cerebral palsy in the future. Delayed cord clamping is to be done to reduce recurrent blood transfusions and decrease the risk of IVH. This article explains the pathogenesis, management, prevention, and future outcomes of IVH.

The Impact of Intraventricular Hemorrhage and Periventricular Leukomalacia on Mortality and Neurodevelopmental Outcome in Very Preterm and Very Low Birthweight Infants: A Prospective Population-based Cohort Study

OBJECTIVE

To survey the incidence of intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL) by gestational age and to report the impact on mortality and neurodevelopmental outcome in very preterm/very low birthweight infants.

STUDY DESIGN

This was a population-based cohort study of 1927 very preterm/very low birthweight infants born in 2014-2016 and admitted to Flemish neonatal intensive care units. Infants underwent standard follow-up assessment until 2 years corrected age with the Bayley Scales of Infant and Toddler Development and neurological assessments.

RESULTS

No brain lesion was present in 31% of infants born at <26 weeks of gestation and 75.8% in infants born at 29-32 weeks of gestation. The prevalence of low-grade IVH/PVL (grades I and II) was 16.8% and 12.7%, respectively. Low-grade IVH/PVL was not related significantly to an increased likelihood of mortality, motor delay, or cognitive delay, except for PVL grade II, which was associated with a 4-fold increase in developing cerebral palsy (OR, 4.1; 95% CI, 1.2-14.6). High-grade lesions (III-IV) were present in 22.0% of the infants born at <26 weeks of gestational and 3.1% at 29-32 weeks of gestation, and the odds of death were ≥14.0 (IVH: OR, 14.0; 95% CI, 9.0-21.9; PVL: OR, 14.1; 95% CI, 6.6-29.9). PVL grades III-IV showed an increased odds of 17.2 for motor delay and 12.3 for cerebral palsy, but were not found to be associated significantly with cognitive delay (OR, 2.9; 95% CI, 0.5-17.5; P = .24).

CONCLUSIONS

Both the prevalence and severity of IVH/PVL decreased significantly with advancing gestational age. More than 75% of all infants with low grades of IVH/PVL showed normal motor and cognitive outcome at 2 years corrected age. High-grade PVL/IVH has become less common and is associated with adverse outcomes.

Brain injury and long-term outcome after neonatal surgery for non-cardiac congenital anomalies

BACKGROUND

There is growing evidence that neonatal surgery for non-cardiac congenital anomalies (NCCAs) in the neonatal period adversely affects long-term neurodevelopmental outcome. However, less is known about acquired brain injury after surgery for NCCA and abnormal brain maturation leading to these impairments.

METHODS

A systematic search was performed in PubMed, Embase, and The Cochrane Library on May 6, 2022 on brain injury and maturation abnormalities seen on magnetic resonance imaging (MRI) and its associations with neurodevelopment in neonates undergoing NCCA surgery the first month postpartum. Rayyan was used for article screening and ROBINS-I for risk of bias assessment. Data on the studies, infants, surgery, MRI, and outcome were extracted.

RESULTS

Three eligible studies were included, reporting 197 infants. Brain injury was found in n = 120 (50%) patients after NCCA surgery. Sixty (30%) were diagnosed with white matter injury. Cortical folding was delayed in the majority of cases. Brain injury and delayed brain maturation was associated with a decrease in neurodevelopmental outcome at 2 years of age.

CONCLUSIONS

Surgery for NCCA was associated with high risk of brain injury and delay in maturation leading to delay in neurocognitive and motor development. However, more research is recommended for strong conclusions in this group of patients.

IMPACT

Brain injury was found in 50% of neonates who underwent NCCA surgery. NCCA surgery is associated with a delay in cortical folding. There is an important research gap regarding perioperative brain injury and NCCA surgery.

Contrast-enhanced subharmonic aided pressure estimation for assessment of intracranial pressure in vivo

BACKGROUND

Intracranial pressure (ICP) monitoring in children currently requires invasive techniques. Subharmonic aided pressure estimation (SHAPE) uses contrast-enhanced ultrasound (CEUS) to measure intravascular and interstitial pressure, but utility in ICP measurements has yet to be explored.

OBJECTIVE

The objective of this study was to investigate SHAPE as a novel tool for noninvasive ICP measurements in fetal lambs.

MATERIALS AND METHODS

Eighteen fetal lambs at 107-139 days gestational age (term = 145 days) underwent subdural ICP catheter placement. The brain was imaged in the coronal plane in CEUS mode optimized for SHAPE, while infusing an US contrast agent into the fetal circulation. After SHAPE calibration, saline was infused via the subdural catheter to increase ICP. Five-second SHAPE cine clips were obtained at various ICPs. Subharmonic intensity values of the whole brain and thalami were correlated with ICP values using mixed effects linear regression analyses and the strength of the relationship was evaluated by Spearman's rank-order correlation.

RESULTS

Forty-nine experiments produced 723 datapoints, including SHAPE intensity values and mean ICP measurements. There was a statistically significant inverse relationship between SHAPE intensity values and ICP measurements in the whole brain and thalami (median rho value - 0.58 and - 0.56, respectively).

CONCLUSION

SHAPE intensity values of the brain demonstrate an inverse and statistically significant correlation with in vivo ICP measurements in an animal model.

Prevention of Neurological Sequelae in Preterm Infants

BACKGROUND

Preterm birth is one of the world's critical health problems, with an incidence of 5% to 18% of living newborns according to various countries. White matter injuries due to preoligodendrocytes deficits cause hypomyelination in children born preterm. Preterm infants also have multiple neurodevelopmental sequelae due to prenatal and perinatal risk factors for brain damage. The purpose of this work was to explore the effects of the brain risk factors and MRI volumes and abnormalities on the posterior motor and cognitive development at 3 years of age.

METHODS

A total of 166 preterm infants were examined before 4 months and clinical and MRI evaluations were performed. MRI showed abnormal findings in 89% of the infants. Parents of all infants were invited to receive the Katona neurohabilitation treatment. The parents of 128 infants accepted and received Katona's neurohabilitation treatment. The remaining 38 infants did not receive treatment for a variety of reasons. At the three-year follow-up, Bayley's II Mental Developmental Index (MDI) and the Psychomotor Developmental Index (PDI) were compared between treated and untreated subjects.

RESULTS

The treated children had higher values of both indices than the untreated. Linear regression showed that the antecedents of placenta disorders and sepsis as well as volumes of the corpus callosum and of the left lateral ventricle significantly predicted both MDI and PDI, while Apgar < 7 and volume of the right lateral ventricle predicted the PDI.

CONCLUSIONS

(1) The results indicate that preterm infants who received Katona's neurohabilitation procedure exhibited significantly better outcomes at 3 years of age compared to those who did not receive the treatment. (2) The presence of sepsis and the volumes of the corpus callosum and lateral ventricles at 3-4 months were significant predictors of the outcome at 3 years of age.

Targeting the brain 5-HT7 receptor to prevent hypomyelination in a rodent model of perinatal white matter injuries

Approximately 15 million babies are born prematurely every year and many will face lifetime motor and/or cognitive deficits. Children born prematurely are at higher risk of developing perinatal brain lesions, especially white matter injuries (WMI). Evidence in humans and rodents demonstrates that systemic inflammation-induced neuroinflammation, including microglial and astrocyte reactivity, is the prominent processes of WMI associated with preterm birth. Thus, a new challenge in the field of perinatal brain injuries is to develop new neuroprotective strategies to target neuroinflammation to prevent WMI. Serotonin (5-HT) and its receptors play an important role in inflammation, and emerging evidence indicates that 5-HT may regulate brain inflammation by the modulation of microglial reactivity and astrocyte functions. The present study is based on a mouse model of WMI induced by intraperitoneal (i.p.) injections of IL-1β during the first 5 days of life. In this model, certain key lesions of preterm brain injuries can be summarized by (i) systemic inflammation, (ii) pro-inflammatory microglial and astrocyte activation, and (iii) inhibition of oligodendrocyte maturation, leading to hypomyelination. We demonstrate that Htr7 mRNA (coding for the HTR7/5-HT7 receptor) is significantly overexpressed in the anterior cortex of IL-1β-exposed animals, suggesting it as a potential therapeutic target. LP-211 is a specific high-affinity HTR7 agonist that crosses the blood-brain barrier (BBB). When co-injected with IL-1β, LP-211 treatment prevented glial reactivity, the down-regulation of myelin-associated proteins, and the apparition of anxiety-like phenotypes. Thus, HTR7 may represent an innovative therapeutic target to protect the developing brain from preterm brain injuries.

Ultrasonographic evaluation of the early brain growth pattern in very low birth weight infants

BACKGROUND

Preterm infants develop smaller brain volumes compared to term newborns. Our aim is to study early brain growth related to perinatal factors in very low birth weight infants (VLBWI).

METHODS

Manual segmentation of total brain volume (TBV) was performed in weekly 3D-ultrasonographies in our cohort of VLBWI. We studied the brain growth pattern related to term magnetic resonance image (term-MRI).

RESULTS

We found different brain growth trajectories, with smaller brain volumes and a decrease in brain growth rate in those VLBWI who would later have an abnormal term-MRI (mean TBV 190.68 vs. 213.9 cm3; P = 0.0001 and mean TBV growth rate 14.35 (±1.27) vs. 16.94 (±2.29) cm3/week; P = 0.0001). TBV in those with normal term-MRI was related to gestational age (GA), being small for gestational age (SGA), sex, and duration of parenteral nutrition (TPN) while in those with abnormal term-MRI findings it was related to GA, SGA, TPN, and comorbidities. We found a deceleration in brain growth rate in those with ≥3 comorbidities.

CONCLUSIONS

An altered brain growth pattern in VLBWI who subsequently present worst scores on term-MRI is related to GA, being SGA and comorbidities. Early ultrasonographic monitoring of TBV could be useful to detect deviated patterns of brain growth.

IMPACT STATEMENT

We describe the brain growth pattern in very low birth weight infants during their first postnatal weeks. Brain growth may be affected in the presence of certain perinatal factors and comorbidities, conditioning a deviation of the normal growth pattern. The serial ultrasound follow-up of these at-risk patients allows identifying these brain growth patterns early, which offers a window of opportunity for implementing earlier interventions.

Brain Damage in the Preterm Infant: Clinical Aspects and Recent Progress in the Prevention and Treatment

Although the prevalence of brain injury and related neurodevelopmental disabilities resulting from preterm birth are major public health concerns, there are no definite neuroprotective strategies to prevent or reduce brain injury. The pattern of brain injury seen in preterm infants has evolved into more subtle lesions that are still essential to diagnose regarding neurodevelopmental outcomes. There is no specific effective method for the treatment of premature infant brain injury, and the focus of clinical treatment is still on prevention. Prevention of this injury requires insight into the pathogenesis, but many gaps exist in our understanding of how neonatal treatment procedures and medications impact cerebral hemodynamics and preterm brain injury. Many studies provide evidence about the prevention of premature infant brain injury, which is related to some drugs (such as erythropoietin, melatonin, mesenchymal stem cells, etc.). However, there are still some controversies about the quality of research and the effectiveness of therapy. This review aims to recapitulate the results of preclinical studies and provide an update on the latest developments around etiological pathways, prevention, and treatment.

The association of γδT lymphocytes with cystic leukomalacia in premature infants

Background

Periventricular leukomalacia (PVL) is an essential cause of cerebral palsy in preterm infants, and cystic PVL (cPVL) is the most severe form of the disease. The pathogenesis of cPVL is complex, and immune imbalances and inflammatory responses may play an essential role in it.

Objective

This study aimed to investigate the correlation between peripheral blood lymphocyte subsets, especially γδT cells with the pathogenesis of cPVL in preterm infants.

Methods

Peripheral blood from preterm infants with GA < 32 weeks and BW < 1,500 g was used in this study and was collected at 34 weeks corrected gestational age and within 24 h after the diagnosis with cranial MRI or cranial ultrasound. The infants were divided into cPVL groups and control groups. Flow cytometry was used to detect peripheral blood γδT, CD3+, CD4+, CD8+, and the proportion of total lymphocytes. Multiplex cell assays were used to detect the concentration of extracellular serum cytokines IL-6, IL-2, IL-8, IL-17A, IL-10, IL-1RA, eotaxin (CCL11), MCP-1 (CCL2), CXCL1, G-CSF, and IFNγ. A follow-up visit was carried out when the patient was 3 years old.

Results

After correcting for confounding factors, the proportion of peripheral blood γδT in the cPVL group was significantly lower than that in the control group (β: 0.216; 95% CI: 0.058-0.800, P < 0.022). Peripheral blood γδT (AUC: 0.722, P=0.006) and multivariate binary regression model (AUC: 0.865, P < 0.000) have good diagnostic values for cPVL. Peripheral blood γδT has some predictive power for neurodevelopmental outcomes in preterm infants (AUC: 0.743, P = 0.002).

Conclusion

It seems that peripheral blood γδT cells are inversely correlated with cPVL, which is not only a risk factor for cPVL disease but also neurodevelopmental outcomes in preterm infants. However, the causality of cPVL and various lymphocytes is unclear and needs further study.

Newborn differential DNA methylation and subcortical brain volumes as early signs of severe neurodevelopmental delay in a South African Birth Cohort Study

OBJECTIVES

Early detection of neurodevelopmental delay is crucial for intervention and treatment strategies. We analysed associations between newborn DNA methylation (DNAm), neonatal magnetic resonance imaging (MRI) neuroimaging data, and neurodevelopment.

METHODS

Neurodevelopment was assessed in 161 children from the South African Drakenstein Child Health Study at 2 years of age using the Bayley Scales of Infant and Toddler Development III. We performed an epigenome-wide association study of neurodevelopmental delay using DNAm from cord blood. Subsequently, we analysed if associations between DNAm and neurodevelopmental delay were mediated by altered neonatal brain volumes (subset of 51 children).

RESULTS

Differential DNAm at SPTBN4 (cg26971411, Δbeta = -0.024, p-value = 3.28 × 10-08), and two intergenic regions (chromosome 11: cg00490349, Δbeta = -0.036, p-value = 3.02 × 10-08; chromosome 17: cg15660740, Δbeta = -0.078, p-value = 6.49 × 10-08) were significantly associated with severe neurodevelopmental delay. While these associations were not mediated by neonatal brain volume, neonatal caudate volumes were independently associated with neurodevelopmental delay, particularly in language (Δcaudate volume = 165.30 mm3, p = 0.0443) and motor (Δcaudate volume = 365.36 mm3, p-value = 0.0082) domains.

CONCLUSIONS

Differential DNAm from cord blood and increased neonatal caudate volumes were independently associated with severe neurodevelopmental delay at 2 years of age. These findings suggest that neurobiological signals for severe developmental delay may be detectable in very early life.

Short-term effects of fresh mother's own milk in very preterm infants

Fresh mother's own milk (MOM) can protect preterm infants from many complications. Often MOM is pasteurized for safety, which can deactivate cellular and bioactive components with protective benefits. Questions remain regarding whether pasteurized MOM provides the same benefits as fresh MOM. The aim of this study was to evaluate the association and feasibility of feeding very preterm infants with fresh MOM. This prospective cohort study included 157 very preterm infants born before 32 weeks' gestational age and with a birthweight below 1500 g. Of these, 82 infants were included in the fresh MOM without any processing group and 75 infants were included in the pasteurized never-frozen MOM (PNFMOM) group. The mortality rate, survival rate without severe complication, incidence of complications, feeding indexes and growth velocities were compared to assess the association and feasibility of feeding fresh MOM. Compared with the PNFMOM group, the fresh MOM group had a higher survival rate without severe complications (p = 0.014) and a lower incidence of bronchopulmonary dysplasia (p = 0.010) after adjustment for confounders. The fresh MOM group regained birthweight earlier (p = 0.021), reached total enteral feeding earlier (p = 0.024), and received total parenteral nutrition for less time (p = 0.045). No adverse events associated with fresh MOM feeding were recorded. Feeding fresh MOM may reduce the incidence of complications in very premature infants. Fresh MOM was shown to be a feasible feeding strategy to improve preterm infants' outcomes.

Imaging of Premature Infants

According to the World Health Organization (WHO), 15 million babies are born preterm each year. Preterm infants are those born at less than 37 weeks, while extremely and very preterm neonates include those born at 22 to less than 32 weeks gestational age. Infants that fail to make it to term are missing a key part in neurodevelopment, as weeks 24 to 40 are a critical period of brain development. Neonatal brain injury is a crucial predictor for mortality and morbidity in premature and low birth weight (<1500 g) infants. Although the complications associated with preterm birth continue to be the number one cause of death in children under 5, the survival rates are increasing (Volpe, 2019). Despite this, the incidence of comorbidities, such as learning disabilities and visual and hearing problems, is still high. The functional deficits seen in these infants can be contributed to the white matter abnormalities (WMA) that have been found in 50% to 80% of extremely and very preterm neonates. While numerous, the etiology of the neonatal brain injury is essential for determining the mortality and morbidities of the infant, as there is an increased risk for both intraventricular hemorrhage (IVH) and periventricular leukomalacia (PVL), which can be attributed to their lack of cerebrovascular autoregulation and hypoxic events. Neuroimaging plays a key role in detecting and assessing these neurologic injuries that preterm infants are at risk for. It is essential to diagnose these events early on to assess neurologic damage, minimize disease progression, and provide supportive care. Brain MRI and cranial ultrasound (CUS) are both extensively used neuroimaging techniques to assess WMA, and it has become ever more important to determine the best imaging techniques and modalities with the increasing survival rates and high incidence of comorbidities among these infants.

Alteration of the Oligodendrocyte Lineage Varies According to the Systemic Inflammatory Stimulus in Animal Models That Mimic the Encephalopathy of Prematurity

Preterm birth before the gestational age of 32 weeks is associated with the occurrence of specific white matter damage (WMD) that can compromise the neurological outcome. These white matter abnormalities are embedded in more global brain damage defining the encephalopathy of prematurity (EoP). A global reduction in white matter volume that corresponds to chronic diffuse WMD is the most frequent form in contemporary cohorts of very preterm infants. This WMD partly results from alterations of the oligodendrocyte (OL) lineage during the vulnerability window preceding the beginning of brain myelination. The occurrence of prenatal, perinatal and postnatal events in addition to preterm birth is related to the intensity of WMD. Systemic inflammation is widely recognised as a risk factor of WMD in humans and in animal models. This review reports the OL lineage alterations associated with the WMD observed in infants suffering from EoP and emphasizes the role of systemic inflammation in inducing these alterations. This issue is addressed through data on human tissue and imaging, and through neonatal animal models that use systemic inflammation to induce WMD. Interestingly, the OL lineage damage varies according to the inflammatory stimulus, i.e., the liposaccharide portion of the E.Coli membrane (LPS) or the proinflammatory cytokine Interleukin-1β (IL-1β). This discrepancy reveals multiple cellular pathways inducible by inflammation that result in EoP. Variable long-term consequences on the white matter morphology and functioning may be speculated upon according to the intensity of the inflammatory challenge. This hypothesis emerges from this review and requires further exploration.

A Neurologist's Guide to Neonatal Neurodevelopmental Assessments and Preterm Brain Injury

Despite advances in medical care and improved survival of extremely preterm infants, rates of neurodevelopmental impairment remain high. Outcomes are significantly improved with early intervention, but infants must be appropriately identified to facilitate services. Neuroimaging provides important information regarding neurodevelopmental outcomes but prognosticating and communicating risk remains challenging. Standardized neonatal neurodevelopmental assessments provide supplemental information to aid in the identification of high-risk infants and counseling for their families.

Combining advanced MRI and EEG techniques better explains long-term motor outcome after very preterm birth

BACKGROUND

Preterm born children are at high risk for adverse motor neurodevelopment. The aim of this study was to establish the relationship between motor outcome and advanced magnetic resonance imaging (MRI) and electroencephalography (EEG) measures.

METHODS

In a prospective cohort study of 64 very preterm born children, the motor outcome was assessed at 9.83 (SD 0.70) years. Volumetric MRI, diffusion tensor imaging (DTI), and EEG were acquired at 10.85 (SD 0.49) years. We investigated associations between motor outcome and brain volumes (white matter, deep gray matter, cerebellum, and ventricles), white matter integrity (fractional anisotropy and mean, axial and radial diffusivity), and brain activity (upper alpha (A2) functional connectivity and relative A2 power). The independence of associations with motor outcome was investigated with a final model. For each technique, the measure with the strongest association was selected to avoid multicollinearity.

RESULTS

Ventricular volume, radial diffusivity, mean diffusivity, relative A2 power, and A2 functional connectivity were significantly correlated to motor outcome. The final model showed that ventricular volume and relative A2 power were independently associated with motor outcome (B = -9.42 × 10^-5, p = 0.027 and B = 28.9, p = 0.007, respectively).

CONCLUSIONS

This study suggests that a lasting interplay exists between brain structure and function that might underlie motor outcome at school age.

IMPACT

This is the first study that investigates the relationships between motor outcome and brain volumes, DTI, and brain function in preterm born children at school age. Ventricular volume and relative upper alpha power on EEG have an independent relation with motor outcome in preterm born children at school age. This suggests that there is a lasting interplay between structure and function that underlies adverse motor outcome.

Real-time motion monitoring improves functional MRI data quality in infants

Imaging the infant brain with MRI has improved our understanding of early neurodevelopment. However, head motion during MRI acquisition is detrimental to both functional and structural MRI scan quality. Though infants are typically scanned while asleep, they commonly exhibit motion during scanning causing data loss. Our group has shown that providing MRI technicians with real-time motion estimates via Framewise Integrated Real-Time MRI Monitoring (FIRMM) software helps obtain high-quality, low motion fMRI data. By estimating head motion in real time and displaying motion metrics to the MR technician during an fMRI scan, FIRMM can improve scanning efficiency. Here, we compared average framewise displacement (FD), a proxy for head motion, and the amount of usable fMRI data (FD ≤ 0.2 mm) in infants scanned with (n = 407) and without FIRMM (n = 295). Using a mixed-effects model, we found that the addition of FIRMM to current state-of-the-art infant scanning protocols significantly increased the amount of usable fMRI data acquired per infant, demonstrating its value for research and clinical infant neuroimaging.

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MRI studies of the infant brain are critical for studying early neurodevelopment.

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Head motion diminishes MRI data quality, which can adversely affect infant imaging.

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We show that real-time head motion monitoring improves fMRI scan quality in infants.

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Being able to monitor motion during fMRI acquisition improves scanning efficiency.

The Impact of Different Degrees of Intraventricular Hemorrhage on Mortality and Neurological Outcomes in Very Preterm Infants: A Prospective Cohort Study

Objective

Intraventricular hemorrhage (IVH) is a common complication in preterm infants and is related to neurodevelopmental outcomes. Infants with severe IVH are at higher risk of adverse neurological outcomes and death, but the effect of low-grade IVH remains controversial. The purpose of this study was to evaluate the impact of different degrees of IVH on mortality and neurodevelopmental outcomes in very preterm infants.

Methods

Preterm infants with a gestational age of &lt;30 weeks admitted to neonatal intensive care units were included. Cerebral ultrasound was examined repeatedly until discharge or death. All infants were followed up to 18–24 months of corrected age. The impact of different grades of IVH on death and neurodevelopmental disability was assessed by multiple logistic regression.

Results

A total of 1,079 preterm infants were included, and 380 (35.2%) infants had grade I-II IVH, 74 (6.9%) infants had grade III-IV IVH, and 625 (57.9%) infants did not have IVH. The mortality in the non-IVH, I-II IVH, and III-IV IVH groups was 20.1, 19.7, and 55.2%, respectively (p &lt; 0.05), and the incidence of neurodevelopmental disabilities was 13.9, 16.1, and 43.3%, respectively (p &lt; 0.05), at 18–24 months of corrected age. After adjusting for confounding factors, preterm infants with III-IV IVH had higher rates of cerebral palsy [26.7 vs. 2.4%, OR = 6.10, 95% CI (1.840–20.231), p = 0.003], disability [43.3 vs. 13.9%, OR = 2.49, 95% CI (1.059–5.873), p = 0.037], death [55.2 vs. 20.1%, OR = 3.84, 95% CI (2.090–7.067), p &lt; 0.001], and disability + death [73.7 vs. 28.7%, OR = 4.77, 95% CI (2.518–9.021), p &lt; 0.001] compared to those without IVH. However, the mortality and the incidence of neurodevelopmental disability in infants with I-II IVH were similar to those without IVH (p &gt; 0.05).

Conclusions

Severe IVH but not mild IVH increased the risk of mortality and neurodevelopmental disability in very preterm infants.

Cyto/myeloarchitecture of cortical gray matter and superficial white matter in early neurodevelopment: multimodal MRI study in preterm neonates

The cerebral cortex undergoes rapid microstructural changes throughout the third trimester. Recently, there has been growing interest on imaging features that represent cyto/myeloarchitecture underlying intracortical myelination, cortical gray matter (GM), and its adjacent superficial whitematter (sWM). Using 92 magnetic resonance imaging scans from 78 preterm neonates, the current study used combined T1-weighted/T2-weighted (T1w/T2w) intensity ratio and diffusion tensor imaging (DTI) measurements, including fractional anisotropy (FA) and mean diffusivity (MD), to characterize the developing cyto/myeloarchitectural architecture. DTI metrics showed a linear trajectory: FA decreased in GM but increased in sWM with time; and MD decreased in both GM and sWM. Conversely, T1w/T2w measurements showed a distinctive parabolic trajectory, revealing additional cyto/myeloarchitectural signature inferred. Furthermore, the spatiotemporal courses were regionally heterogeneous: central, ventral, and temporal regions of GM and sWM exhibited faster T1w/T2w changes; anterior sWM areas exhibited faster FA increases; and central and cingulate areas in GM and sWM exhibited faster MD decreases. These results may explain cyto/myeloarchitectural processes, including dendritic arborization, synaptogenesis, glial proliferation, and radial glial cell organization and apoptosis. Finally, T1w/T2w values were significantly associated with 1-year language and cognitive outcome scores, while MD significantly decreased with intraventricular hemorrhage.

Discrete white matter abnormalities at age 8-11 years in children born extremely preterm are not associated with adverse cognitive or motor outcomes

AIM

Little is known about the prevalence of discrete white matter abnormalities (WMA) beyond the first years in children born extremely preterm (EPT) and the relation to neurodevelopmental outcomes. Our aim was to investigate the prevalence of discrete WMA in children born EPT and the relationship to neonatal white matter injuries (WMI), white matter (WM) volume, WM diffusivity and neurodevelopment.

METHODS

The study was a part of a longitudinal follow-up study of EPT neonates. All children were scanned at Karolinska University hospital 2004-2007 (neonates) and 2014-2015 (children at 8-11 years). WMA was qualitatively assessed by visual inspection. Developmental assessment was conducted at 12 years.

RESULTS

In total, 112 children (median age 10.3 years, 56 girls) underwent MRI of the brain (68 EPT, 45 controls). In the EPT group, a subset had MRI around term equivalent age (n = 61). In the EPT group, the prevalence of discrete WMA at 8-11 years was 52%. There was a positive association between WMI at TEA and 8-11 years. There was no association between WMI and WM volumes or diffusivity at 8-11 years. Discrete WMA was not related to neurodevelopmental outcomes.

CONCLUSION

Discrete WMA was prevalent in children born EPT at 8-11 years but were not related to neurodevelopmental outcomes.

Intraoperative cerebral oxygen saturation and neurological outcomes following surgical management of necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis: Predictive factors of neurological complications following neonatal necrotizing enterocolitis

BACKGROUND

The goal of the present study was to investigate intraoperative factors associated with major neurological complications at 1 year following surgery for necrotizing enterocolitis.

MATERIAL AND METHODS

The study consisted of a retrospective review of medical charts of patients operated for over one calendar year in one institution. Data collected included demographic data, cardiac resuscitation at birth, Bell classification, antibiotics usage, time of day of surgery, surgical technique, surgical duration, type of ventilation, intraoperative vasoactive agents, and albumin use, nadir cerebral saturation, the decrease in cerebral saturation from baseline, the time period when cerebral saturation was at least 20% below baseline, and the mean arterial pressure at nadir cerebral saturation. Reported follow-up complications were assessed during formal neonatologist consultation and additional imaging exploration as needed. Analyses included descriptive statistics, and univariable and multivariable statistics.

RESULTS

The study included 32 patients with no prior clinical neurological complications, of which 25 had normal cerebral imaging. Severe neurological complications occurred in nine patients at 1 year: Intraventricular hemorrhage (N = 2) and Periventricular leukomalacia (N = 7). However, preoperative cerebral imaging was lacking in seven patients. Consequently, the observed neurological complications at 1 year might be present before the surgery. Multivariable analysis found the decrease in cerebral saturation ≥36% from baseline as the only factor associated with the occurrence of those complications.

CONCLUSION

Intraoperative decrease of cerebral oxygen saturation below ≥36% from baseline is associated with severe neurological complications in neonates undergoing surgery for necrotizing enterocolitis.

Early detection and treatment of attention deficits in preterm and at term infants with risk factors for brain damage

Cognitive deficits in infants born preterm and infants at term with risk factors for brain damage are a common outcome. Attention deficits in preterm infants are related to the development of attention-deficit/hyperactivity disorder (ADHD), and therefore, there is a need for earlier evaluations and treatment procedures that are implemented before the presence of signs of ADHD.

METHODS

We studied preterm (74%) and term infants with the Infant Scale of Selective Attention (ISSA, Escala de Evaluación de la Atención Selectiva (EEAS), in Spanish). This scale evaluates both visual- and auditory-orienting attention. Two groups participated, one with attention deficits (n = 26) and another with regular performance (n = 36). An early attention-stimulation program (EASP) was implemented in the infant group with attention deficits from three to eight months of age. All infants underwent magnetic resonance imaging (MRI), and visual and auditory evoked responses were assessed.

RESULTS

All infants had prenatal and perinatal risk factors for brain damage and abnormal MRI findings, and the majority had abnormalities compatible with white matter injury. However, there were four infants with porencephalic cysts; 3 of them were in the treated group. At the beginning of the treatment, ISSA values showed differences between groups. These differences persisted for five months in the visual test and up to the sixth month in the auditory evaluation. Afterward, there were no significant differences, indicating that infants with attention deficits had satisfactorily responded to the treatment.

CONCLUSIONS

The ISSA is helpful for the early evaluation of visual and auditory attention. Infants with attention deficits react well enough after six months of EASP.

Relationship between the Quantitative Indicators of Cranial MRI and the Early Neurodevelopment of Preterm Infants

Aim

To explore the relationship between the quantitative indicators (biparietal width, interhemispheric distance) of the cranial MRI for preterm infants at 37 weeks of postmenstrual age (PMA) and neurodevelopment at 6 months of corrected age.

Methods

A total of 113 preterm infants (gestational age < 37 weeks) delivered in the Obstetrics Department of the First People's Hospital of Lianyungang from September 2018 to February 2020 and directly transferred to the Neonatology Department for treatment were enrolled in this study. Based on their development quotient (DQ), the patients were divided into the normal (DQ ≥ 85, n = 76) group and the abnormal (DQ < 85, n = 37) group. Routine cranial MRI (cMRI) was performed at 37 weeks of PMA to measure the biparietal width (BPW) and interhemispheric distance (IHD). At the corrected age of 6 months, Development Screening Test (for children under six) was used to assess the participants' neurodevelopment.

Results

Univariate analysis showed statistically significant differences in BPW, IHD, and the incidence of bronchopulmonary dysplasia between the normal and the abnormal groups (P < 0.05), while no statistically significant differences were found in maternal complications and other clinical conditions between the two groups (P > 0.05). Binary logistic regression analysis demonstrated statistically significant differences in IHD and BPW between the normal and the abnormal groups (95% CI: 1.629-12.651 and 0.570-0.805, respectively; P = 0.004 and P < 0.001, respectively), while no significant differences were found in the incidence of bronchopulmonary dysplasia between the two groups (95% CI: 0.669-77.227, P = 0.104). Receiver operating characteristic curve revealed that the area under the curve of BPW, IHD, and the joint predictor (BPW + IHD) were 0.867, 0.805, and 0.881, respectively (95% CI: 0.800-0.933, 0.710-0.900, and 0.819-0.943, respectively; all P values < 0.001).

Conclusion

BPW and IHD, the two quantitative indicators acquired by cMRI, could predict the neurodevelopmental outcome of preterm infants at the corrected age of 6 months. The combination of the two indicators showed an even higher predictive value.

The effects of neonatal procedural pain and maternal isolation on hippocampal cell proliferation and reelin concentration in neonatal and adult male and female rats

Preterm births accounted for over 10% of all U.S. live births in 2019 and the rate is rising. Neonatal stressors, especially procedural pain, experienced by preterm infants in the neonatal intensive care unit (NICU) have been associated with neurodevelopmental impairments. Parental care can alleviate stress during stressful or painful procedures; however, infants in the NICU often receive reduced parental care compared with their peers. Animal studies suggest that decreased maternal care similarly impairs neurodevelopment but also influences the effects of neonatal pain. It is important to mimic both stressors in animal models of neonatal stress exposure. In this study, researchers investigated the individual and combined impact of neonatal pain and maternal isolation on reelin protein levels and cellular proliferation in the hippocampal dentate gyrus of 8 days old and adult rats. Exposure to either stressor individually, but not both, increased reelin levels in the dentate gyrus of adult females without significantly altering reelin levels in adult males. However, cell proliferation levels at either age were unaffected by the early-life stressors. These results suggest that each early-life stressor has a unique effect on markers of brain development and more research is needed to further investigate their distinct influences.

Counseling parents of premature neonates on neuroimaging findings

While medical advancements have led to improved survival of extremely premature infants, children remain at risk for brain injury and neurodevelopmental impairment. Brain imaging can offer insight into an infant's acute and long-term outcome; however, counseling parents about the results and implications of brain imaging remains challenging. The purpose of this article is to review the current literature and describe the challenges associated with counseling families of premature infants on neuroimaging findings. We propose a framework to guide clinicians in counseling parents about brain imaging results, informed by best practices in other disciplines: (FIGURE): 1) Formulate a plan 2) Identify parental needs and values 3) Give information 4) Acknowledge Uncertainty 5) Recognize and Respond to emotions 6) Discuss Expectations and Establish follow-up.

Apnoea of Prematurity and Neurodevelopmental Outcomes: Current Understanding and Future Prospects for Research

Infants who are born prematurely are at significant risk of apnoea. In addition to the short-term consequences such as hypoxia, apnoea of prematurity has been associated with long-term morbidity, including poor neurodevelopmental outcomes. Clinical trials have illustrated the importance of methylxanthine drugs, in particular caffeine, in reducing the risk of long term adverse neurodevelopmental outcomes. However, the extent to which apnoea is causative of this secondary neurodevelopmental delay or is just associated in a background of other sequelae of prematurity remains unclear. In this review, we first discuss the pathophysiology of apnoea of prematurity, previous studies investigating the relationship between apnoea and neurodevelopmental delay, and treatment of apnoea with caffeine therapy. We propose a need for better methods of measuring apnoea, along with improved understanding of the neonatal brain's response to consequent hypoxia. Only then can we start to disentangle the effects of apnoea on neurodevelopment in preterm infants. Moreover, by better identifying those infants who are at risk of apnoea, and neurodevelopmental delay, we can work toward a risk stratification system for these infants that is clinically actionable, for example, with doses of caffeine tailored to the individual. Optimising treatment of apnoea for individual infants will improve neonatal care and long-term outcomes for this population.

Predictive value of brain MRI at term-equivalent age in extremely preterm children on neurodevelopmental outcome at school-age

This study's objective was to correlate the abnormalities in brain MRIs performed at corrected-term age for minor or moderate neurocognitive disorders in children school-age born extremely premature (EPT) and without serious sequelae such as autism, cerebral palsy, mental impairment. Data were issued from a cross-sectional multicenter study (GP-Qol study, number NCT01675726). Clinical examination and psychometric assessments were performed when the children were between 7 and 10 years old during a day-long evaluation. Term-equivalent age brain MRIs on EPT were analyzed with a standardized scoring system. There were 114 children included in the study. The mean age at the time of evaluation, was 8.47 years old (± 0.70). 59% of children with at least one cognitive impairment and 53% who had a dysexecutive disorder. Only ten EPT (8.7%) presented moderate to severe white and grey matter abnormalities. These moderate to severe grey matter abnormalities were associated with at least two abnormal executive functions [OR 3.08 (95% CI 1.04-8.79), p = 0.04] and language delay [OR 3.25 (95% CI 1.03-9.80), p = 0.04]. These results remained significant in the multivariate analysis. Moderate to severe ventricular dilatation abnormalities (15%, n = 17) were associated with ideomotor dyspraxia [OR 7.49 (95% CI 1.48-35.95), p = 0.02] and remained significant in multivariate analysis [OR 11.2 (95% CI 1.45-131.4), p = 0.02]. Biparietal corrected diameters were moderate abnormal in 20% of cases (n = 23) and were associated to visuo spatial integration delay [OR 4.13 (95% CI 1.23-13.63), p = 0.02]. Cerebral MRI at term-equivalent age with scoring system analysis can provide information on long-term neuropsychological outcomes at school-age in EPTs children having no severe disability.

Serum Activin A as Brain Injury Biomarker in the First Three Days of Life. A Prospective Case-Control Longitudinal Study in Human Premature Neonates

Disruption of normal intrauterine brain development is a significant consequence of premature birth and may lead to serious complications, such as neonatal brain injury (NBI). This prospective case-control longitudinal study aimed at determining the levels and prognostic value of serum activin A during the first three days of life in human premature neonates which later developed NBI. It was conducted in a single tertiary hospital and eligible participants were live-born premature (<34 weeks) neonates. Each case (n = 29) developed NBI in the form of an intraventricular haemorrhage, or periventricular leukomalacia, and was matched according to birth weight and gestational age to one neonate with normal head ultrasound scans. Serum activin A levels in both groups showed a stable concentration during the first three days of life as no difference was observed within the two groups from the first to the third day. Neonates diagnosed with NBI had significantly higher activin A levels during the first two days of life compared to control neonates and its levels correlated to the severity of NBI during the second and third day of life. Although serum activin A on the second day was the best predictor for neonates at risk to develop NBI, the overall predictive value was marginally fair (area under the ROC-curve 69.2%). Activin A, in combination with other biomarkers, may provide the first clinically useful panel for the early detection of premature neonates at high risk of NBI.

Early skin contact combined with mother's breastfeeding to shorten the process of premature infants ≤ 30 weeks of gestation to achieve full oral feeding: the study protocol of a randomized controlled trial

Background

Most hospitalized preterm infants experience difficulties in transitioning from tube feeding to full oral feeding. Interventions to promote full oral feeding in preterm infants in the neonatal intensive care unit (NICU) are limited to pacifier use or bottle-feeding exercises. Skin contact has been shown to be beneficial to start and maintain lactation and provide preterm infants with the opportunity to suck on the mother’s breast, which may promote further development of the preterm infant’s suckling patterns. The objective of this study is to compare and evaluate the effects of skin contact combined with breastfeeding (suck on the mother’s empty breast) as compared to the routine pacifier suckling training model in achieving full oral feeding for infants whose gestational age are ≤ 30 weeks.

Methods

This is a single-center, randomized controlled clinical trial conducted in the NICU and designed according to the SPIRIT Statement. The subjects included in the study are premature infants born between April 2020 and July 2021 with a gestational age of ≤30 weeks, birth weight of <1500 g, admission age of <72 h, and absence of congenital malformations. Those with oxygenation indices of >40 and those born to mothers with poor verbal communication skills will be excluded. A sample of 148 infants is needed. The infants will be randomized to the intervention (skin contact combined with mother’s breastfeeding model) or control group (routine pacifier sucking training model). The primary outcome is the time required to achieve full oral feeding. The secondary outcomes are the breastfeeding abilities of preterm infants as assessed by the Preterm Infant Breastfeeding Behavior Scale (PIBBS), breastfeeding rates at 3 and 6 months corrected gestational age, complication rates, duration of oxygen requirement, days of hospital stay, and satisfaction of parents.

Discussion

This paper describes the first single-center, open-label, randomized clinical trial on this topic and will provide crucial information to support the implementation of skin contact combined with the breastfeeding model in the NICU setting.

Trial registration

ClinicalTrials.gov NCT 04283682. Registered on 8 February 2020.

Supplementary Information

The online version contains supplementary material available at 10.1186/s13063-021-05605-x.

Lipid Intake and Neurodevelopment in Preterm Infants

Preterm infants are born before the critical period of lipid accretion and brain development that occurs during the third trimester of pregnancy. Dietary lipids serve as an important source of energy and are involved in complex processes that are essential for normal central nervous system development. In addition to traditional neurodevelopmental testing, novel quantitative magnetic resonance imaging (MRI) techniques are now available to evaluate the impact of nutritional interventions on early preterm brain development. Trials of long-chain polyunsaturated fatty acid supplementation have yielded inconsistent effects on neurodevelopmental outcomes and quantitative MRI findings. Recent studies using quantitative MRI suggest a positive impact of early lipid intake on brain volumes and white matter microstructural organization by term-equivalent age.

Precision Medicine in Neonates: A Tailored Approach to Neonatal Brain Injury

Despite advances in neonatal care to prevent neonatal brain injury and neurodevelopmental impairment, predicting long-term outcome in neonates at risk for brain injury remains difficult. Early prognosis is currently based on cranial ultrasound (CUS), MRI, EEG, NIRS, and/or general movements assessed at specific ages, and predicting outcome in an individual (precision medicine) is not yet possible. New algorithms based on large databases and machine learning applied to clinical, neuromonitoring, and neuroimaging data and genetic analysis and assays measuring multiple biomarkers (omics) can fulfill the needs of modern neonatology. A synergy of all these techniques and the use of automatic quantitative analysis might give clinicians the possibility to provide patient-targeted decision-making for individualized diagnosis, therapy, and outcome prediction. This review will first focus on common neonatal neurological diseases, associated risk factors, and most common treatments. After that, we will discuss how precision medicine and machine learning (ML) approaches could change the future of prediction and prognosis in this field.

Preterm infants with severe brain injury demonstrate unstable physiological responses during maternal singing with music therapy: a randomized controlled study

Preterm infants with severe brain injury are at high risk for poor outcomes and, therefore, may benefit from developmental care modalities such as music therapy (MT). In this prospective, randomized intervention, preterm infants with severe brain injury (grade 3 or 4 intraventricular hemorrhage or periventricular leukomalacia) who underwent skin-to-skin contact (SSC) with or without maternal singing during MT were evaluated for physiological responses, including autonomic nervous system stability (low frequency (LF)/high frequency (HF) power), heart rate, respiratory rate, oxygen saturation, and behavioral state. Maternal anxiety state and physiological data were also evaluated. A total of 35 preterm infants with severe brain injuries were included in the study analysis. Higher mean ± standard deviation (SD) LF/HF ratio (1.8 ± 0.7 vs. 1.1 ± 0.25, p = 0.01), higher mean ± SD heart rate (145 ± 15 vs. 132 ± 12 beats per minute, p = 0.04), higher median (interquartile range) infant behavioral state (NIDCAP manual for naturalistic observation and the Brazelton Neonatal Behavioral Assessment) score (3 (2-5) vs. 1 (1-3), p = 0.03), and higher mean ± SD maternal anxiety (state-trait anxiety inventory) score (39.1 ± 10.4 vs. 31.5 ± 7.3, p = 0.04) were documented in SSC combined with maternal singing during MT, as compared to SSC alone.Conclusion: Maternal singing during MT for preterm infants with severe brain injury induces physiological and behavioral instability and increases maternal anxiety during NICU hospitalization. A unique MT intervention should be designed for preterm infants with severe brain injury and their mothers. What is Known: • Preterm infants with severe brain injury are at high risk for poor outcomes. • Music therapy benefits brain development of preterm infants without severe brain injury, however it is unknown whether maternal singing during music therapy for preterm infants with severe brain injury is beneficial. What is New: • Maternal singing during music therapy for preterm infants with severe brain injury induces physiological and behavioral instability and increases maternal anxiety during NICU hospitalization. • A unique music therapy intervention should be designed for preterm infants with severe brain injury and their mothers.

Brain volumetry in fetuses that deliver very preterm: An MRI pilot study

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Fetuses that subsequently deliver very preterm have a reduction in cortical and extra cerebrospinal fluid volumes.

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If such alterations commence antenatally this suggests a role for earlier administration of neuroprotective agents.

Background

Infants born preterm are at increased risk of neurological complications resulting in significant morbidity and mortality. The exact mechanism and the impact of antenatal factors has not been fully elucidated, although antenatal infection/inflammation has been implicated in both the aetiology of preterm birth and subsequent neurological sequelae. It is therefore hypothesized that processes driving preterm birth are affecting brain development in utero. This study aims to compare MRI derived regional brain volumes in fetuses that deliver < 32 weeks with fetuses that subsequently deliver at term.

Methods

Women at high risk of preterm birth, with gestation 19.4–32 weeks were recruited prospectively. A control group was obtained from existing study datasets. Fetal MRI was performed on a 1.5 T or 3 T MRI scanner: T2-weighted images were obtained of the fetal brain. 3D brain volumetric datsets were produced using slice to volume reconstruction and regional segmentations were produced using multi-atlas approaches for supratentorial brain tissue, lateral ventricles, cerebellum cerebral cortex and extra-cerebrospinal fluid (eCSF). Statistical comparison of control and high-risk for preterm delivery fetuses was performed by creating normal ranges for each parameter from the control datasets and then calculating gestation adjusted z scores. Groups were compared using t-tests.

Results

Fetal image datasets from 24 pregnancies with delivery < 32 weeks and 87 control pregnancies that delivered > 37 weeks were included. Median gestation at MRI of the preterm group was 26.8 weeks (range 19.4–31.4) and control group 26.2 weeks (range 21.7–31.9). No difference was found in supra-tentorial brain volume, ventricular volume or cerebellar volume but the eCSF and cerebral cortex volumes were smaller in fetuses that delivered preterm (p < 0.001 in both cases).

Conclusion

Fetuses that deliver preterm have a reduction in cortical and eCSF volumes. This is a novel finding and needs further investigation. If alterations in brain development are commencing antenatally in fetuses that subsequently deliver preterm, this may present a window for in utero therapy in the future.

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

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

Germinal Matrix-Intraventricular Hemorrhage: A Tale of Preterm Infants

Germinal matrix-intraventricular hemorrhage (GM-IVH) is a common intracranial complication in preterm infants, especially those born before 32 weeks of gestation and very-low-birth-weight infants. Hemorrhage originates in the fragile capillary network of the subependymal germinal matrix of the developing brain and may disrupt the ependymal lining and progress into the lateral cerebral ventricle. GM-IVH is associated with increased mortality and abnormal neurodevelopmental outcomes such as posthemorrhagic hydrocephalus, cerebral palsy, epilepsy, severe cognitive impairment, and visual and hearing impairment. Most affected neonates are asymptomatic, and thus, diagnosis is usually made using real-time transfontanellar ultrasound. The present review provides a synopsis of the pathogenesis, grading, incidence, risk factors, and diagnosis of GM-IVH in preterm neonates. We explore brief literature related to outcomes, management interventions, and pharmacological and nonpharmacological prevention strategies for GM-IVH and posthemorrhagic hydrocephalus.

Therapeutic potential of stem cells for preterm infant brain damage: Can we move from the heterogeneity of preclinical and clinical studies to established therapeutics?

Acquired perinatal brain injuries are a set of conditions that remains a key challenge for neonatologists and that have significant social, emotional and financial implications for our communities. In our perspective article, we will introduce perinatal brain injury focusing specifically on the events leading to brain damage in preterm born infants and outcomes for these infants. Then we will summarize and discuss the preclinical and clinical studies testing the efficacy of stem cells as neuroprotectants in the last ten years in perinatal brain injury. There are no therapies to treat brain damage in preterm born infants and a primary finding from this review is that there is a scarcity of stem cell trials focused on overcoming brain injuries in these infants. Overall, across all forms of perinatal brain injury there is a remarkable heterogeneity in previous and on-going preclinical and clinical studies in terms of the stem cell type, animal models/patient selection, route and time of administration. Despite the quality of many of the studies this variation makes it difficult to reach a valid consensus for future developments. However, it is clear that stem cells (and stem cell derived exosomes) can reduce perinatal brain injury and our field needs to work collectively to refine an effective protocol for each type of injury. The use of standardized stem cell products and testing these products across multiple models of injury will provide a stronger framework for clinical trials development.

Abnormal Nutritive Sucking as an Indicator of Neonatal Brain Injury

A term neonate is born with the ability to suck; this neuronal network is already formed and functional by 28 weeks gestational age and continues to evolve into adulthood. Because of the necessity of acquiring nutrition, the complexity of the neuronal network needed to suck, and neuroplasticity in infancy, the skill of sucking has the unique ability to give insight into areas of the brain that may be damaged either during or before birth. Interpretation of the behaviors during sucking shows promise in guiding therapies and how to potentially repair the damage early in life, when neuroplasticity is high. Sucking requires coordinated suck-swallow-breathe actions and is classified into two basic types, nutritive and non-nutritive. Each type of suck has particular characteristics that can be measured and used to learn about the infant's neuronal circuitry. Basic sucking and swallowing are present in embryos and further develop to incorporate breathing ex utero. Due to the rhythmic nature of the suck-swallow-breathe process, these motor functions are controlled by central pattern generators. The coordination of swallowing, breathing, and sucking is an enormously complex sensorimotor process. Because of this complexity, brain injury before birth can have an effect on these sucking patterns. Clinical assessments allow evaluators to score the oral-motor pattern, however, they remain ultimately subjective. Thus, clinicians are in need of objective measures to identify the specific area of deficit in the sucking pattern of each infant to tailor therapies to their specific needs. Therapeutic approaches involve pacifiers, cheek/chin support, tactile, oral kinesthetic, auditory, vestibular, and/or visual sensorimotor inputs. These therapies are performed to train the infant to suck appropriately using these subjective assessments along with the experience of the therapist (usually a speech therapist), but newer, more objective measures are coming along. Recent studies have correlated pathological sucking patterns with neuroimaging data to get a map of the affected brain regions to better inform therapies. The purpose of this review is to provide a broad scope synopsis of the research field of infant nutritive and non-nutritive feeding, their underlying neurophysiology, and relationship of abnormal activity with brain injury in preterm and term infants.

A Narrative Review of Circular RNAs in Brain Development and Diseases of Preterm Infants

Circular RNAs (circRNAs) generated by back-splicing are the vital class of non-coding RNAs (ncRNAs). Circular RNAs are highly abundant and stable in eukaryotes, and many of them are evolutionarily conserved. They are blessed with higher expression in mammalian brains and could take part in the regulation of physiological and pathophysiological processes. In addition, premature birth is important in neurodevelopmental diseases. Brain damage in preterm infants may represent the main cause of long-term neurodevelopmental disorders in surviving babies. Until recently, more and more researches have been evidenced that circRNAs are involved in the pathogenesis of encephalopathy of premature. We aim at explaining neuroinflammation promoting the brain damage. In this review, we summarize the current findings of circRNAs properties, expression, and functions, as well as their significances in the neurodevelopmental impairments, white matter damage (WMD) and hypoxic-ischemic encephalopathy (HIE). So we think that circRNAs have a direct impact on neurodevelopment and brain injury, and will be a powerful tool in the repair of the injured immature brain. Even though their exact roles and mechanisms of gene regulation remain elusive, circRNAs have potential applications as diagnostic biomarkers for brain damage and the target for neuroprotective intervention.

Noncontact optical imaging of brain hemodynamics in preterm infants: a preliminary study

Extremely preterm infants' hemodynamic instability places them at high risk of brain injury. Currently there is no reliable bedside method to continuously monitor cerebral hemodynamics in the neonatal intensive care unit (NICU). This paper reports a feasibility study to adapt and test an innovative speckle contrast diffuse correlation tomography (scDCT) device for noncontact, high-density, 3D imaging of cerebral blood flow (CBF) in preterm infants. The scDCT scans a focused point near-infrared illumination to multiple source positions for deep tissue penetration, and controls an electron multiplying charge-coupled-device camera with thousands of pixels to achieve a high-density sampling. The optimized scDCT for use in preterm infants was first evaluated against an established diffuse correlation spectroscopy in an infant-head-simulating phantom with known properties. The observed significant correlation between the two measurements verified the capability of scDCT for transcranial brain imaging. The insignificant influence of transparent incubator wall on scDCT measurements was then confirmed by comparing adult forearm blood flow responses to artery cuff occlusions measured inside and outside the incubator. Finally, the scDCT device was moved to the NICU to image CBF variations in two preterm infants. Infant #1 with no major organ deficits showed little CBF fluctuation over the first 3 weeks of life. Infant #2 showed a significant CBF increase after the 2 h pharmacotherapy for patent ductus arteriosus closure. While these CBF variations meet physiological expectations, the fact that no significant changes are noted with peripheral monitoring of blood oxygen saturation suggests necessity of direct cerebral monitoring. This feasibility study with timely technology development is an important and necessary step towards larger clinical studies with more subjects to further validate it for continuous monitoring and instant management of cerebral pathologies and interventions in the NICU.

A Model of Germinal Matrix Hemorrhage in Preterm Rat Pups

Germinal matrix hemorrhage (GMH) is a serious complication in extremely preterm infants associated with neurological deficits and mortality. The purpose of the present study was to develop and characterize a grade III and IV GMH model in postnatal day 5 (P5) rats, the equivalent of preterm human brain maturation. P5 Wistar rats were exposed to unilateral GMH through intracranial injection into the striatum close to the germinal matrix with 0.1, 0.2, or 0.3 U of collagenase VII. During 10 days following GMH induction, motor functions and body weight were assessed and brain tissue collected at P16. Animals were tested for anxiety, motor coordination and motor asymmetry on P22–26 and P36–40. Using immunohistochemical staining and neuropathological scoring we found that a collagenase dose of 0.3 U induced GMH. Neuropathological assessment revealed that the brain injury in the collagenase group was characterized by dilation of the ipsilateral ventricle combined with mild to severe cellular necrosis as well as mild to moderate atrophy at the levels of striatum and subcortical white matter, and to a lesser extent, hippocampus and cortex. Within 0.5 h post-collagenase injection there was clear bleeding at the site of injury, with progressive increase in iron and infiltration of neutrophils in the first 24 h, together with focal microglia activation. By P16, blood was no longer observed, although significant gray and white matter brain infarction persisted. Astrogliosis was also detected at this time-point. Animals exposed to GMH performed worse than controls in the negative geotaxis test and also opened their eyes with latency compared to control animals. At P40, GMH rats spent more time in the center of open field box and moved at higher speed compared to the controls, and continued to show ipsilateral injury in striatum and subcortical white matter. We have established a P5 rat model of collagenase-induced GMH for the study of preterm brain injury. Our results show that P5 rat pups exposed to GMH develop moderate brain injury affecting both gray and white matter associated with delayed eye opening and abnormal motor functions. These animals develop hyperactivity and show reduced anxiety in the juvenile stage.

Germinal Matrix-Intraventricular Hemorrhage of the Preterm Newborn and Preclinical Models: Inflammatory Considerations

The germinal matrix-intraventricular hemorrhage (GM-IVH) is one of the most important complications of the preterm newborn. Since these children are born at a critical time in brain development, they can develop short and long term neurological, sensory, cognitive and motor disabilities depending on the severity of the GM-IVH. In addition, hemorrhage triggers a microglia-mediated inflammatory response that damages the tissue adjacent to the injury. Nevertheless, a neuroprotective and neuroreparative role of the microglia has also been described, suggesting that neonatal microglia may have unique functions. While the implication of the inflammatory process in GM-IVH is well established, the difficulty to access a very delicate population has lead to the development of animal models that resemble the pathological features of GM-IVH. Genetically modified models and lesions induced by local administration of glycerol, collagenase or blood have been used to study associated inflammatory mechanisms as well as therapeutic targets. In the present study we review the GM-IVH complications, with special interest in inflammatory response and the role of microglia, both in patients and animal models, and we analyze specific proteins and cytokines that are currently under study as feasible predictors of GM-IVH evolution and prognosis.

Plasma and Cerebrospinal Fluid Candidate Biomarkers of Neonatal Encephalopathy Severity and Neurodevelopmental Outcomes

OBJECTIVES

To identify candidate biomarkers in both plasma and cerebrospinal fluid (CSF) that are associated with neonatal encephalopathy severity measured by encephalopathy grade, seizures, brain injury by magnetic resonance imaging (MRI), and neurodevelopmental outcomes at 15-30 months.

STUDY DESIGN

A retrospective cohort study of plasma (N = 155, day of life 0-1) and CSF (n = 30, day of life 0-7) from neonates with neonatal encephalopathy and healthy neonates born at term (N = 30, ≥36 weeks of gestation) was conducted. We measured central nervous system necrosis (glial fibrillary acidic protein [GFAP], neurogranin [NRGN], tau), inflammatory (interleukin [IL]-6, IL-8, IL-10), and trophic (brain-derived neurotrophic factor [BDNF], vascular endothelial growth factor) proteins. Clinical outcomes were Sarnat scores of encephalopathy, seizures, MRI scores, and Bayley Scales of Infant and Toddler Development III at 15-30 months.

RESULTS

Plasma NRGN, tau, IL-6, IL-8, and IL-10 were greater, whereas BDNF and vascular endothelial growth factor were lower in patients with neonatal encephalopathy vs controls. In plasma, tau, GFAP, and NRGN were directly and BDNF inversely associated with encephalopathy grade. IL-6 was inversely related to seizures. Tau was directly related to MRI abnormalities. Tau was inversely associated with Bayley Scales of Infant and Toddler Development III cognitive and motor outcomes. In CSF, NRGN was inversely associated with cognitive, motor, and language measures. GFAP, IL-6, and IL-10 were inversely related to cognitive and motor outcomes. IL-8 was inversely related to motor outcomes. CSF candidate biomarkers showed no significant relationships with encephalopathy grade, seizures, or MRI abnormalities.

CONCLUSIONS

Plasma candidate biomarkers predicted encephalopathy severity, seizures, MRI abnormalities, and neurodevelopmental outcomes at 15-30 months.