Effects of hypothermia for perinatal asphyxia on childhood outcomes

Analysis of CTG patterns in cases with metabolic acidosis at birth with and without neonatal neurological alterations

OBJECTIVE

To determine cardiotocographic patterns in newborns with metabolic acidosis, based on clinical signs of neurological alteration (NA) and the need for hypothermic treatment.

METHODS

All term newborns with metabolic acidosis in a single center from 2016 to 2020 were included in the study. Three segments of intrapartum CTG (cardiotocography) were considered (first 30 min of active labor, 90 to 30 min before birth, and last 30 min before delivery) and a longitudinal analysis of CTG pattern was performed according to the 2015 FIGO classification.

RESULTS

Three hundred and twenty-four neonates with metabolic acidosis diagnosed at birth were divided into three groups: the first group included all neonates with any clinical sign of neurological alteration, requiring hypothermia according to the recommendation of the Italian Society of Neonatology (group TNA-Treated neurological Alteration, n = 17), the second encompassed neonates with any clinical sign of neurological alteration not requiring hypothermia (group NTNA-Not Treated neurological Alteration, n = 83), and the third enclosed all neonates without any sign of clinical neurological involvement (group NoNA-No neurological Alteration, n = 224). The most frequent alterations of CTG in TNA group were late decelerations, reduced variability, bradycardia, and tachysystole. Unexpectedly, from the longitudinal analysis of the CTG, 49% of all cases with metabolic acidosis never showed a pathological CTG with normal trace at the beginning of labor followed by normal or suspicious trace in the final part of labor, the same as in TNA and NTNA groups (10 and 39%, respectively).

CONCLUSIONS

CTG has limited specificity in identifying cases of acidosis at birth, even in babies who will develop NA.

Application of the Hammersmith Infant Neurological Examination in the developmental follow-up of high-risk infants

AIM

To investigate the independent influences affecting the global score of the Hammersmith Infant Neurological Examination (HINE) in the early life of high-risk infants and to provide evidence for early effective screening and for evaluating interventions.

METHOD

We conducted a prospective cohort study of 258 high-risk infants assessed by the HINE and Gesell Developmental Diagnosis Schedule at 3, 6, 9, and 12 months corrected age. A multiple linear regression model was developed to investigate independent influences on HINE global score at 3 months corrected age. The accuracy of the HINE global score was analysed by calculating the discriminant, concurrent, and predictive validities according to ages.

RESULTS

There were nine independent influences affecting the HINE global score at 3 months corrected age in high-risk infants. The discriminant, concurrent, and predictive validities of the HINE for gross motor developmental delays at 12 months corrected age were all statistically significant (p < 0.05).

INTERPRETATION

Different neonatal clinical settings are related to the HINE global score of high-risk infants early in life. The HINE can be used for longitudinal monitoring of neurological development in the first year of life in a typical Chinese clinical setting and the findings at all four ages tested relate to neuromotor outcomes at 12 months corrected age.

Advances in Electroencephalographic Biomarkers of Neonatal Hypoxic Ischemic Encephalopathy

Electroencephalography (EEG) is a key objective biomarker of newborn brain function, delivering critical, cotside insights to aid the management of encephalopathy. Access to continuous EEG is limited, forcing reliance on subjective clinical assessments. In hypoxia ischaemia, the primary cause of encephalopathy, alterations in EEG patterns correlate with. injury severity and evolution. As HIE evolves, causing secondary neuronal death, EEG can track injury progression, informing neuroprotective strategies, seizure management and prognosis. Despite its value, challenges with interpretation and lack of on site expertise has limited its broader adoption. Technological advances, particularly in digital EEG and machine learning, are enhancing real-time analysis. This will allow EEG to expand its role in HIE diagnosis, management and outcome prediction.

Long-Term Outcomes Following Hypoxic Ischemic Encephalopathy

Hypoxic ischemic encephalopathy (HIE) is the most common cause of neonatal encephalopathy and results in significant morbidity and mortality. Long-term outcomes of the condition encompass impairments across all developmental domains. While therapeutic hypothermia (TH) has improved outcomes for term and late preterm infants with moderate to severe HIE, trials are ongoing to investigate the use of TH for infants with mild or preterm HIE. There is no evidence that adjuvant therapies in combination with TH improve long-term outcomes. Numerous trials of various adjuvant therapies are underway in the quest to further improve outcomes for infants with HIE.

Single-Center Experience with Therapeutic Hypothermia for Hypoxic-Ischemic Encephalopathy in Infants with <36 Weeks' Gestation

OBJECTIVE

 Hypoxic-ischemic encephalopathy (HIE) is a leading cause of morbidity and mortality in neonates. Therapeutic hypothermia (TH) has improved outcomes and mortality in infants with >36 weeks' gestational age (GA) with moderate-to-severe HIE. There are limited data on the safety and efficacy of TH in preterm infants with HIE. This study describes our experience and examines the safety of TH in neonates with <36 weeks' GA.

STUDY DESIGN

A single-center, retrospective study of preterm neonates born at <36 weeks' GA with moderate-to-severe HIE and treated with TH, compared to a cohort of term neonates with HIE (≥37 weeks' GA), was conducted. The term cohort was matched for degree of background abnormality on electroencephalogram, sex, inborn versus outborn status, and birth year. Medical records were reviewed for pregnancy and delivery complications, need for transfusion, sedation and antiseizure medications, electroencephalography and imaging findings, and in-hospital mortality.

RESULTS

 Forty-two neonates born at <36 weeks' GA with HIE received TH between 2005 and 2022. Data from 42 term neonates were analyzed for comparison. The average GA of the preterm cohort was 34.6 weeks and 39.3 weeks for the term cohort. Apgar scores, degree of acidosis, and need for blood product transfusions were similar between groups. Preterm infants were more likely to require inotropic support (55 vs. 29%, p = 0.026) and hydrocortisone (36 vs. 12%, p = 0.019) for hypotension. The proportion of infants without evidence of injury on magnetic resonance imaging was similar in both groups: 43 versus 50% in preterm and term infants, respectively. No significant difference was found in mortality between groups.

CONCLUSION

 In this single-center cohort, TH in preterm infants appears to be as safe as in term infants, with no significant increase in intracranial bleeds or mortality. Preterm infants more frequently required inotropes and steroids for hypotension. Further research is needed to determine efficacy of TH in preterm infants.

KEY POINTS

· TH is used off-protocol in preterm infants.. · Preterm and term infants have similar mortality.. · Preterm cohort required more inotropic support..

Hammersmith

目的

探讨影响高危儿生命早期Hammersmith婴儿神经学检查(HINE)总分的独立影响因素，并为早期有效筛查和评估干预疗效提供证据。

方法

我们对258名高危儿进行了前瞻性队列研究，分别在矫正3、6、9 和12月龄时接受了 HINE和Gesell发育诊断表的评估。一个多元线性回归模型被建立以探究矫正3月龄时HINE总分的独立影响因素。通过计算不同年龄段的区分效度、同时效度和预测效度，分析HINE 总分的准确性。

结果

高危儿HINE总分在矫正3月龄时有9个独立影响因素。在矫正2月龄时，HINE总分对粗大运动发育迟缓的区分效度、同时效度和预测效度均有统计学意义(P < 0.05)。

结果

不同的新生儿临床状况与其生命早期HINE总分有关。在典型的中国临床环境中，HINE可用于纵向监测高危儿出生后第一年的神经系统发育情况，而且四个年龄段的筛查结果都与矫正12月龄时的神经运动发育结果有关。

Key Inflammatory Biomarkers in Perinatal Asphyxia: A Comprehensive Review

This article summarizes the current evidence regarding inflammatory biomarkers (placental and postnatal) and provides a comprehensive understanding of their roles: (1) diagnostic accuracy to predict the severity of hypoxic-ischemia encephalopathy (HIE), (2) value in assessing treatment responses, and (3) prediction of both short- and long-term neurodevelopmental outcomes. In the early critical stages of perinatal asphyxia, inflammatory biomarkers may guide clinical decision-making. Additional research is required to increase our understanding of the optimal utility of biomarkers to predict the severity, evolution, and developmental outcomes after exposure to HIE.

Moving the Needle in Low-Resource Settings: Is Hypothermia a Friend or a Foe?

Hypoxic-ischemic encephalopathy in low resource settings is associated with low occurrence of perinatal sentinel events, growth restriction, short birth depression, early seizure onset, white matter injury, and non-acute hypoxia on whole genome expression profile suggesting that intra-partum hypoxia might be occurring from a normal or augmented labor process in an already compromised fetus. Induced hypothermia increases mortality and does not reduce brain injury. Strict adherence to the updated National Neonatology forum guidelines is essential to prevent harm from induced hypothermia in low resource settings.

Neuroprotection provided by hypothermia initiated with high transnasal flow with ambient air in a model of pediatric cardiac arrest

Clinical trials of hypothermia after pediatric cardiac arrest (CA) have not seen robust improvement in functional outcome, possibly because of the long delay in achieving target temperature. Previous work in infant piglets showed that high nasal airflow, which induces evaporative cooling in the nasal mucosa, reduced regional brain temperature uniformly in half the time needed to reduce body temperature. Here, we evaluated whether initiation of hypothermia with high transnasal airflow provides neuroprotection without adverse effects in the setting of asphyxic CA. Anesthetized piglets underwent sham-operated procedures (n = 7) or asphyxic CA with normothermic recovery (38.5°C; n = 9) or hypothermia initiated by surface cooling at 10 (n = 8) or 120 (n = 7) min or transnasal cooling initiated at 10 (n = 7) or 120 (n = 7) min after resuscitation. Hypothermia was sustained at 34°C with surface cooling until 20 h followed by 6 h of rewarming. At 4 days of recovery, significant neuronal loss occurred in putamen and sensorimotor cortex. Transnasal cooling initiated at 10 min significantly rescued the number of viable neurons in putamen, whereas levels in putamen in other hypothermic groups remained less than sham levels. In sensorimotor cortex, neuronal viability in the four hypothermic groups was not significantly different from the sham group. These results demonstrate that early initiation of high transnasal airflow in a pediatric CA model is effective in protecting vulnerable brain regions. Because of its simplicity, portability, and low cost, transnasal cooling potentially could be deployed in the field or emergency room for early initiation of brain cooling after pediatric CA.NEW & NOTEWORTHY The onset of therapeutic hypothermia after cardiac resuscitation is often delayed, leading to incomplete neuroprotection. In an infant swine model of asphyxic cardiac arrest, initiation of high transnasal airflow to maximize nasal evaporative cooling produced hypothermia sufficient to provide neuroprotection that was not inferior to body surface cooling. Because of its simplicity and portability, this technique may be of use in the field or emergency room for rapid brain cooling in pediatric cardiac arrest victims.

Neocortical cholinergic pathology after neonatal brain injury is increased by Alzheimer's disease-related genes in mice

Hypoxic-ischemic encephalopathy (HIE) in neonates causes mortality and neurologic morbidity, including poor cognition with a complex neuropathology. Injury to the cholinergic basal forebrain and its rich innervation of cerebral cortex may also drive cognitive pathology. It is uncertain whether genes associated with adult cognition-related neurodegeneration worsen outcomes after neonatal HIE. We hypothesized that neocortical damage caused by neonatal HI in mice is ushered by persistent cholinergic innervation and interneuron (IN) pathology that correlates with cognitive outcome and is exacerbated by genes linked to Alzheimer's disease. We subjected non-transgenic (nTg) C57Bl6 mice and mice transgenically (Tg) expressing human mutant amyloid precursor protein (APP-Swedish variant) and mutant presenilin (PS1-ΔE9) to the Rice-Vannucci HI model on postnatal day 10 (P10). nTg and Tg mice with sham procedure were controls. Visual discrimination (VD) was tested for cognition. Cortical and hippocampal cholinergic axonal and IN pathology and Aβ plaques, identified by immunohistochemistry for choline acetyltransferase (ChAT) and 6E10 antibody respectively, were counted at P210. Simple ChAT+ axonal swellings were present in all sham and HI groups; Tg mice had more than their nTg counterparts, but HI did not affect the number of axonal swellings in APP/PS1 Tg mice. In contrast, complex ChAT+ neuritic clusters (NC) occurred only in Tg mice; HI increased that burden. The abundance of ChAT+ clusters in specific regions correlated with decreased VD. The frequency of attritional ChAT+ INs in the entorhinal cortex (EC) was increased in Tg shams relative to their nTg counterparts, but HI obviated this difference. Cholinergic IN pathology in EC correlated with NC number. The Aβ deposition in APP/PS1 Tg mice was not exacerbated by HI, nor did it correlate with other metrics. Adult APP/PS1 Tg mice have significant cortical cholinergic axon and EC ChAT+ IN pathologies; some pathology was exacerbated by neonatal HI and correlated with VD. Mechanisms of neonatal HI induced cognitive deficits and cortical neuropathology may be modulated by genetic risk, perhaps accounting for some of the variability in outcomes.

Early automated classification of neonatal hypoxic-ischemic encephalopathy - An aid to the decision to use therapeutic hypothermia

OBJECTIVE

The study aimed to address the challenge of early assessment of neonatal hypoxic-ischemic encephalopathy (HIE) severity to identify candidates for therapeutic hypothermia (TH). The objective was to develop an automated classification model for neonatal EEGs, enabling accurate HIE severity assessment 24/7.

METHODS

EEGs recorded within 6 h of life after perinatal anoxia were visually graded into 3 severity groups (HIE French Classification) and quantified using 6 qEEG markers measuring amplitude, continuity and frequency content. Machine learning models were developed on a dataset of 90 EEGs and validated on an independent dataset of 60 EEGs.

RESULTS

The selected model achieved an overall accuracy of 80.6% in the development phase and 80% in the validation phase. Notably, the model accurately identified 28 out of 30 children for whom TH was indicated after visual EEG analysis, with only 2 cases (moderate EEG abnormalities) not recommended for cooling.

CONCLUSIONS

The combination of clinically relevant qEEG markers led to the development of an effective automated EEG classification model, particularly suited for the post-anoxic latency phase. This model successfully discriminated neonates requiring TH.

SIGNIFICANCE

The proposed model has potential as a bedside clinical decision support tool for TH.

Neonatal therapeutic hypothermia in a regional swedish cohort: Adherence to guidelines, transport and outcomes

AIM

Swedish guidelines for therapeutic hypothermia (TH) after perinatal asphyxia were established in 2007, following several randomised studies that demonstrated improved outcomes. We assessed the implementation of hypothermia treatment in a mid-Swedish region with a sizeable proportion of outborn infants.

METHOD

A population-based TH cohort from 2007 to 2015 was scrutinised for adherence to national guidelines, interhospital transport, including the use of a cooling mattress made of phase change material for thermal management, and outcomes.

RESULTS

Of 136 admitted infants, 99 (73 %) were born outside the hospital. Ninety-eight percent fulfilled the criteria for postnatal depression/acidosis, and all patients had moderate-to-severe encephalopathy. Treatment was initiated within 6 h in 85 % of patients; amplitude-integrated electroencephalography/electroencephalography was recorded in 98 %, cranial ultrasound in 78 %, brain magnetic resonance imaging in 79 %, hearing tests in all, and follow-up was performed in 93 %. Although target body temperature was attained later (p < 0.01) in outborn than in inborn infants, at a mean (standard deviations) age of 6.2 (3.2) h vs 4.4 (2.6) h, 40 % of those transported using the cooling mattress were already within the therapeutic temperature range on arrival, and few were excessively cooled. The mortality rate was 23 %, and 38 % of the survivors had neurodevelopmental impairment at a median of 2.5 years.

CONCLUSION

The regionalisation of TH, including interhospital transport, was feasible and resulted in outcomes comparable to those of randomised controlled studies.

Growth trajectories and need for oral feeding support among infants with neonatal encephalopathy treated with therapeutic hypothermia

OBJECTIVE

Identify feeding supports required among infants with neonatal encephalopathy and determine growth trajectories to 3 years.

STUDY DESIGN

Single-center retrospective cohort study of 120 infants undergoing therapeutic hypothermia. Logistic regression and stratified analyses identified whether clinical factors, EEG-determined encephalopathy severity, and MRI-based brain injury predict feeding supports (nasogastric tube, oral feeding compensations) and growth.

RESULTS

50.8% of infants required feeding supports in the hospital, decreasing to 14% at discharge. Moderate-to-severe encephalopathy and basal ganglia injury predicted feeding support needs. Yet, 35% of mildly encephalopathic infants required gavage tubes. Growth trajectories approximated expected growth of healthy infants.

CONCLUSION

Infants with neonatal encephalopathy-even if mild-frequently experience feeding difficulties during initial hospitalization. With support, most achieve full oral feeds by discharge and adequate early childhood growth. Clinical factors may help identify infants requiring feeding support, but do not detect all at-risk infants, supporting routine screening of this high-risk population.

How do we reach the goal of personalized medicine for neuroprotection in neonatal hypoxic-ischemic encephalopathy?

Therapeutic hypothermia is now standard of care for neonates with hypoxic-ischemic encephalopathy (HIE) in high income countries (HIC). Conversely, compelling trial evidence suggests that hypothermia is ineffective, and may be deleterious, in low- and middle-income countries (LMIC), likely reflecting the lower proportion of infants who had sentinel events at birth, suggesting that injury had advanced to a stage when hypothermia is no longer effective. Although hypothermia significantly reduced the risk of death and disability in HICs, many infants survived with disability and in principle may benefit from targeted add-on neuroprotective or neurorestorative therapies. The present review will assess biomarkers that could be used to personalize treatment for babies with HIE - to determine first whether an individual infant is likely to respond to hypothermia, and second, whether additional treatments may be beneficial.

Echinatin alleviates inflammation and pyroptosis in hypoxic-ischemic brain damage by inhibiting TLR4/ NF-κB pathway

Hypoxic ischemic encephalopathy (HIE) is a primary cause of neonatal death and disabilities. The pathogenetic process of HIE is closely associated with neuroinflammation. Therefore, targeting and suppressing inflammatory pathways presents a promising therapeutic strategy for the treatment of HIE. Echinatin is an active component of glycyrrhiza, with anti-inflammatory and anti-oxidative properties. It is commonly combined with other traditional Chinese herbs to exert heat-clearing and detoxifying effects. This study aimed to investigate the anti-inflammatory and neuroprotective effects of Echinatin in neonatal rats with hypoxic-ischemic brain damage, as well as in PC12 cells exposed to oxygen-glucose deprivation (OGD). In vivo, Echinatin effectively reduced cerebral edema and infarct volume, protected brain tissue morphology, improved long-term behavioral functions, and inhibited microglia activation. These effects were accompanied by the downregulation of inflammatory factors and pyroptosis markers. The RNA sequencing analysis revealed an enrichment of inflammatory genes in rats with hypoxic-ischemic brain damage, and Protein-protein interaction (PPI) network analysis identified TLR4, MyD88, and NF-κB as the key regulators. In vitro, Echinatin reduced the levels of TLR4 relevant proteins, inhibited nuclear translocation of NF-κB, reduced the expression of downstreams inflammatory cytokines and pyroptosis proteins, and prevented cell membrane destructions. These findings demonstrated that Echinatin could inhibit the TLR4/NF-κB pathway, thereby alleviating neuroinflammation and pyroptosis. This suggests that Echinatin could be a potential candidate for the treatment of HIE.

Hypothermia protects the integrity of corticospinal tracts and alleviates mitochondria injury after intracerebral hemorrhage in mice

Disruption of corticospinal tracts (CST) is a leading factor for motor impairments following intracerebral hemorrhage (ICH) in the striatum. Previous studies have shown that therapeutic hypothermia (HT) improves outcomes of ICH patients. However, whether HT has a direct protection effect on the CST integrity and the underlying mechanisms remain largely unknown. In this study, we employed a chemogenetics approach to selectively activate bilateral warm-sensitive neurons in the preoptic areas to induce a hypothermia-like state. We then assessed effects of HT treatment on the integrity of CST and motor functional recovery after ICH. Our results showed that HT treatment significantly alleviated axonal degeneration around the hematoma and the CST axons at remote midbrain region, ultimately promoted skilled motor function recovery. Anterograde and retrograde tracing revealed that HT treatment protected the integrity of the CST over an extended period. Mechanistically, HT treatment prevented mitochondrial swelling in degenerated axons around the hematoma, alleviated mitochondrial impairment by reducing mitochondrial ROS accumulation and improving mitochondrial membrane potential in primarily cultured cortical neurons with oxyhemoglobin treatment. Serving as a proof of principle, our study provided novel insights into the application of HT to improve functional recovery after ICH.

Antiapoptotic Effects of Hydroxychloroquine on Hypoxic-Ischemic Injury in Neonatal Rat Brain: May Hydroxychloroquine Be an Adjuvant Theraphy?

OBJECTIVE

Hydroxychloroquine (HCQ) has immunomodulatory, antithrombotic, cardiovascular, antimicrobial, and antineoplastic effects. In this study, we aimed to investigate the antiapoptotic and immunomodulator effects of intraperitoneal HCQ on hypoxic-ischemic (HI) injury in newborn rats.

STUDY DESIGN

Wistar albino rats, 7 to 10 days old, were randomly divided into three groups: hypoxic-ischemic encephalopathy (HIE) group, HIE treated with HCQ group, and Sham group. Left common carotid artery ligation and hypoxia model were performed in HIE and HCQ groups. The HCQ group was treated with 80 mg/kg intraperitoneal HCQ every 24 hours for 3 days, while Sham and HIE groups were given physiological saline. After 72 hours, rats were decapitated and brain tissues were stained with hematoxylin and eosin, TUNEL, and IL-1β for histopathological grading and neuronal cell injury.

RESULTS

Neuronal apoptosis was statistically lower in all neuroanatomical areas in the HCQ group compared with the HIE group. IL-1β-stained areas were similar in both HCQ and HIE groups but significantly higher compared with the Sham group. Histopathological grading scores were found to be lower in the HCQ group on the left parietal cortex and hippocampus region.

CONCLUSION

In this study, we have shown for the first time that HCQ treatment decreased apoptosis in HI newborn rat model in both hemispheres. HCQ may be a promising adjuvant therapy in neonatal HIE.

KEY POINTS

· HCQ decreased neuronal apoptosis in the ischemic penumbra of the rat brain.. · HCQ attenuates hypoxia-ischemia-induced brain injury in neonatal rats.. · HCQ has no anti-inflammatory effect on HI injury..

Trends and hotspots of the neuroprotection of hypothermia treatment: A bibliometric and visualized analysis of research from 1992 to 2023

AIM

Recent studies have extensively investigated hypothermia as a therapeutic approach for mitigating neural damage. Despite this, bibliometric analyses specifically focusing on this area remain scarce. Consequently, this study aims to comprehensively outline the historical framework of research and to pinpoint future research directions and trends.

METHODS

Articles spanning from 2003 to 2023, relevant to both "neuroprotection" and "hypothermia", were sourced from the Web of Science Core Collection. The CiteSpace software facilitated a comprehensive evaluation and analysis of these publications. This analysis included examining the annual productivity, collaboration among nations, institutions, and authors, as well as the network of co-cited references, authors and journals, and the co-occurrence of keywords, and their respective clusters and trends, all of which were visualized.

RESULTS

This study included 2103 articles on the neuroprotection effects of hypothermia, noting a consistent increase in publications since 1992. The United States, the University of California System, and Ji Xunming emerged as the most productive nation, institution, and author, respectively. Analysis of the top 10 co-cited publications revealed that seven articles focused on the effects of hypothermia in infants with hypoxic-ischemic encephalopathy, while three studies addressed cardiac arrest. Shankaran S and the journal Stroke were the most frequently co-cited author and journal, respectively. Keyword cluster analysis identified ischemic stroke as the primary focus of hypothermia therapy historically, with cardiac arrest and neonatal hypoxic-ischemic encephalopathy emerging as current research foci.

CONCLUSIONS

Recent studies on the neuroprotective effects of hypothermia in cardiac arrest and neonatal hypoxic-ischemic encephalopathy suggest that hypothermia may mitigate neural damage associated with these conditions. However, the application of hypothermia in the treatment of ischemic stroke remains confined to animal models and in vitro studies, with a notable absence of evidence from multicenter randomized controlled trials (RCTs). Further research is required to address this gap.

MRI predictors of long-term outcomes of neonatal hypoxic ischaemic encephalopathy: a primer for radiologists

This review aims to serve as a foundational resource for general radiologists, enhancing their understanding of the role of Magnetic Resonance Imaging (MRI) in early prognostication for newborns diagnosed with hypoxic ischaemic encephalopathy (HIE). The article explores the application of MRI as a predictive instrument for determining long-term outcomes in newborns affected by HIE. With HIE constituting a leading cause of neonatal mortality and severe long-term neurodevelopmental impairments, early identification of prognostic indicators is crucial for timely intervention and optimal clinical management. We examine current literature and recent advancements to provide an in-depth overview of MRI predictors, encompassing brain injury patterns, injury scoring systems, spectroscopy, and diffusion imaging. The potential of these MRI biomarkers in predicting long-term neurodevelopmental outcomes and the probability of epilepsy is also discussed.

Therapeutic Hypothermia for Neonatal Hypoxic-Ischemic Encephalopathy: Reducing Variability in Practice through a Collaborative Telemedicine Initiative

OBJECTIVE

 This study aimed to assess the viability of implementing a tele-educational training program in neurocritical care for newborns diagnosed with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia (TH), with the goal of reducing practice variation.

STUDY DESIGN

 Prospective study including newborns with HIE treated with TH from 12 neonatal intensive care units in Brazil conducted from February 2021 to February 2022. An educational intervention consisting of 12 biweekly, 1-hour, live videoconferences was implemented during a 6-month period in all centers. Half of the centers had the assistance of a remote neuromonitoring team. The primary outcome was the rate of deviations from TH protocol, and it was evaluated during a 3-month period before and after the intervention. Logistic regression via generalized estimating equations was performed to compare the primary and secondary outcomes. Protocol deviations were defined as practices not in compliance with the TH protocol provided. A subanalysis evaluated the differences in protocol deviations and clinical variables between centers with and without neuromonitoring.

RESULTS

 Sixty-six (39.5%) newborns with HIE were treated with TH during the preintervention period, 69 (41.3%) during the intervention period and 32 (19.1%) after intervention. There was not a significant reduction in protocol deviations between the pre- and postintervention periods (37.8 vs. 25%, p = 0.23); however, a decrease in the rates of missing Sarnat examinations within 6 hours after birth was seen between the preintervention (n = 5, 7.6%) and postintervention (n = 2, 6.3%) periods (adjusted odds ratio [aOR]: 0.36 [0.25-0.52], p < 0.001). Centers with remote neuromonitoring support had significantly lower rates of seizures (27.6 vs. 57.5%; aOR: 0.26 [0.12-0.55], p < 0.001) and significant less seizure medication (27.6 vs. 68.7%; aOR: 0.17 [0.07-0.4], p < 0.001).

CONCLUSION

 This study shows that implementing a tele-educational program in neonatal neurocritical care is feasible and may decrease variability in the delivery of care to patients with HIE treated with TH.

KEY POINTS

· Neurocritical care strategies vary widely in low- and middle-income countries.. · Heterogeneity of care may lead to suboptimal efficacy of neuroprotective strategies.. · Tele-education and international collaboration can decrease the variability of neurocritical care provided to infants with HIE..

Knowledge mapping of neonatal electroencephalogram: A bibliometric analysis (2004-2022)

BACKGROUND

Electroencephalography (EEG), a widely used noninvasive neurophysiological diagnostic tool, has experienced substantial advancements from 2004 to 2022, particularly in neonatal applications. Utilizing a bibliometric methodology, this study delineates the knowledge structure and identifies emergent trends within neonatal EEG research.

METHODS

An exhaustive literature search was conducted on the Web of Science Core Collection (WoSCC) database to identify publications related to neonatal EEG from 2004 to 2022. Analytical tools such as VOSviewer, CiteSpace, and the R package "bibliometrix" were employed to facilitate this investigation.

RESULTS

The search yielded 2501 articles originating from 79 countries, with the United States and England being the predominant contributors. A yearly upward trend in publications concerning neonatal EEG was observed. Notable research institutions leading this field include the University of Helsinki, University College London, and University College Cork. Clinical Neurophysiology is identified as the foremost journal in this realm, with Pediatrics as the most frequently co-cited journal. The collective body of work from 9977 authors highlights Sampsa Vanhatalo as the most prolific contributor, while Mark Steven Scher is recognized as the most frequently co-cited author. Key terms such as "seizures," "epilepsy," "hypoxic-ischemic encephalopathy," "amplitude-integrated EEG," and "brain injury" represent the focal research themes.

CONCLUSION

This bibliometric analysis offers the first comprehensive review, encapsulating research trends and progress in neonatal EEG. It reveals current research frontiers and crucial directions, providing an essential resource for researchers engaged in neonatal neuroscience.

Exposure to Maternal Diabetes during Pregnancy Is Associated with Aggravated Short-Term Neonatal and Neurological Outcomes following Perinatal Hypoxic-Ischemic Encephalopathy

OBJECTIVE

Infants of diabetic mothers (IDM) are at higher risk of perinatal morbidities and glycemic instability, but the impact of maternal diabetes on neonatal and neurological short-term outcomes of neonates with hypoxic-ischemic encephalopathy (HIE) remains poorly described. Our objective was to determine the impact of maternal diabetes on neonatal and neurological short-term outcomes following neonatal HIE.

STUDY DESIGN

This was a retrospective single-center study including 102 term neonates with HIE who received therapeutic hypothermia (TH) treatment between 2013 and 2020. Multiple regression analysis was used to assess the relationship between the presence of maternal diabetes and short-term outcomes.

RESULTS

Neonates with HIE and maternal diabetes exposure had a significantly lower gestational age at birth (38.6 vs. 39.7 weeks of gestation, p = 0.005) and a significantly higher mean birth weight (3,588 ± 752 vs. 3,214 ± 514 g, p = 0.012). IDM with HIE were ventilated for longer duration (8 vs. 4 days, p = 0.0047) and had a longer neonatal intensive care unit (NICU) stay (18 vs. 11 days, p = 0.0483) as well as took longer time to reach full oral feed (15 vs. 7 days, p = 0.0432) compared with neonates of nondiabetic mother. Maternal diabetes was also associated with an increased risk of death or abnormal neurological examination at discharge in neonates with HIE (odds ratio: 6.41 [1.54-26.32]).

CONCLUSION

In neonates with HIE, maternal diabetes is associated with an increased risk of death or short-term neonatal morbidities, such as longer duration of ventilation, prolonged neonatal stay, greater need for tube feeding, and being discharged with an abnormal neurological examination. Strategies to prevent, reduce, or better control maternal diabetes during pregnancy should be prioritized to minimize complications after perinatal asphyxia.

KEY POINTS

· Maternal DB is associated with unfavorable outcomes.. · IDM have longer ventilatory support and tube feeding.. · IDM have higher risk of abnormal neurological examination..

Regional variability in therapeutic hypothermia eligibility criteria for neonatal hypoxic-ischemic encephalopathy

Early induced therapeutic hypothermia represents the cornerstone treatment in neonates with probable hypoxic-ischemic encephalopathy. The selection of patients for treatment usually involves meeting criteria indicating evidence of perinatal hypoxia-ischemia and the presence of moderate or severe encephalopathy. In this review, we highlight the variability that exists between some of the different regional and national eligibility guidelines. Determining the potential presence of perinatal hypoxia-ischemia may require either one, two or three signs amongst history of acute perinatal event, prolonged resuscitation at delivery, abnormal blood gases and low Apgar score, with a range of cutoff values. Clinical neurological exams often define the severity of encephalopathy differently, with varying number of domains required for determining eligibility and blurred interpretation of findings assigned to different severity grades in different systems. The role of early electrophysiological assessment is weighted differently. A clinical implication is that infants may receive different care depending on the location in which they are born. This could also impact epidemiological data, as inference of rates of moderate-severe encephalopathy based on therapeutic hypothermia rates are misleading and influenced by different eligibility methods used. We would advocate that a universally endorsed single severity staging of encephalopathy is vital for standardizing management and neonatal outcome. IMPACT: Variability exists between regional and national therapeutic hypothermia eligibility guidelines for neonates with probable hypoxic-ischemic encephalopathy. Differences are common in both criteria indicating perinatal hypoxia-ischemia and criteria defining moderate or severe encephalopathy. The role of early electrophysiological assessment is also weighted unequally. This reflects in different individual care and impacts research data. A universally endorsed single severity staging of encephalopathy would be crucial for standardizing management.

Inflammatory, metabolic, and sex-dependent gene-regulatory dynamics of microglia and macrophages in neonatal hippocampus after hypoxia-ischemia

Neonatal hypoxia-ischemia (HI) is a major cause of perinatal death and long-term disabilities worldwide. Post-ischemic neuroinflammation plays a pivotal role in HI pathophysiology. In the present study, we investigated the temporal dynamics of microglia (CX3CR1GFP/+) and infiltrating macrophages (CCR2RFP/+) in the hippocampi of mice subjected to HI at postnatal day 9. Using inflammatory pathway and transcription factor (TF) analyses, we identified a distinct post-ischemic response in CCR2RFP/+ cells characterized by differential gene expression in sensome, homeostatic, matrisome, lipid metabolic, and inflammatory molecular signatures. Three days after injury, transcriptomic signatures of CX3CR1GFP/+ and CCR2RFP/+ cells isolated from hippocampi showed a partial convergence. Interestingly, microglia-specific genes in CX3CR1GFP/+ cells showed a sexual dimorphism, where expression returned to control levels in males but not in females during the experimental time frame. These results highlight the importance of further investigations on metabolic rewiring to pave the way for future interventions in asphyxiated neonates.

Leflunomide Treatment Does Not Protect Neural Cells following Oxygen-Glucose Deprivation (OGD) In Vitro

Neonatal hypoxia-ischemia (HI) affects 2-3 per 1000 live births in developed countries and up to 26 per 1000 live births in developing countries. It is estimated that of the 750,000 infants experiencing a hypoxic-ischemic event during birth per year, more than 400,000 will be severely affected. As treatment options are limited, rapidly identifying new therapeutic avenues is critical, and repurposing drugs already in clinical use offers a fast-track route to clinic. One emerging avenue for therapeutic intervention in neonatal HI is to target mitochondrial dysfunction, which occurs early in the development of brain injury. Mitochondrial dynamics are particularly affected, with mitochondrial fragmentation occurring at the expense of the pro-fusion protein Optic Atrophy (OPA)1. OPA1, together with mitofusins (MFN)1/2, are required for membrane fusion, and therefore, protecting their function may also safeguard mitochondrial dynamics. Leflunomide, an FDA-approved immunosuppressant, was recently identified as an activator of MFN2 with partial effects on OPA1 expression. We, therefore, treated C17.2 cells with Leflunomide before or after oxygen-glucose deprivation, an in vitro mimic of HI, to determine its efficacy as a neuroprotection and inhibitor of mitochondrial dysfunction. Leflunomide increased baseline OPA1 but not MFN2 expression in C17.2 cells. However, Leflunomide was unable to promote cell survival following OGD. Equally, there was no obvious effect on mitochondrial morphology or bioenergetics. These data align with studies suggesting that the tissue and mitochondrial protein profile of the target cell/tissue are critical for taking advantage of the therapeutic actions of Leflunomide.

Socioemotional and Psychological Outcomes of Hypoxic-Ischemic Encephalopathy: A Systematic Review

BACKGROUND AND OBJECTIVES

Therapeutic hypothermia has reduced the risk of death or major disability following perinatal hypoxic-ischemic encephalopathy (HIE); however, many children who experience perinatal HIE still go on to develop personal and behavioral challenges, which can be difficult for caregivers and a public health burden for society. Our objective with this review is to systematically identify and synthesize studies that evaluate associations between perinatal HIE and socioemotional or psychological outcomes.

METHODS

We screened all search-returned journal articles from Cochrane Library, Embase, Medline, PsycINFO, Scopus, and Web of Science from data inception through February 1, 2023. Keywords related to HIE (eg, neonatal encephalopathy, neonatal brain injury) and outcomes (eg, social*, emotion*, behav* problem, psycholog*, psychiatr*) were searched with a predefined search string. We included all observational human studies reporting socioemotional or psychological sequelae of term HIE. Study data were recorded on standardized sheets, and the Newcastle-Ottawa Scale was adapted to assess study quality.

RESULTS

We included 43 studies documenting 3244 HIE participants and 2132 comparison participants. We found statistically significant associations between HIE and social and emotional, behavioral, and psychological and psychiatric deficits throughout infancy, childhood, and adolescence (19 studies). The authors of the included studies also report nonsignificant findings (11 studies) and outcomes without statistical comparison (25 studies).

CONCLUSIONS

Perinatal HIE may be a risk factor for a range of socioemotional and psychological challenges in the short- and long-term. Routine screening, early intervention, and follow-up support may be particularly beneficial to this population.

Parent Experience of Hypoxic-Ischemic Encephalopathy and Hypothermia: A Call for Trauma Informed Care

OBJECTIVE

Therapeutic hypothermia (TH) is the standard treatment for hypoxic-ischemic encephalopathy (HIE). We surveyed parents of infants treated with TH about their experiences of communication and parental involvement in the neonatal intensive care unit (NICU).

STUDY DESIGN

A 29-question anonymous survey was posted on a parent support (web site: https://www.hopeforhie.org ) and sent to members via e-mail. Responses from open-ended questions were analyzed using thematic analysis.

RESULTS

A total of 165 respondents completed the survey and 108 (66%) infants were treated with TH. 79 (48%) respondents were dissatisfied/neutral regarding the quality of communication in the NICU, whereas 127 (77%) were satisfied/greatly satisfied with the quality of parental involvement in the NICU. Six themes were identified as follows: (1) setting for communication: parents preferred face to face meetings with clinicians; (2) content and clarity of language: parents valued clear language (use of layman's terms) and being explicitly told the medical diagnosis of HIE; (3) immediate and longitudinal emotional support: parents required support from clinicians to process the trauma of the birth experience and hypothermia treatment; (4) clinician time and scheduling: parents valued the ability to join rounds and other major conversations about infant care; (5) valuing the parent role: parents desired being actively involved in rounds, care times, and decision-making; (6) physical presence and touch: parents valued being physically present and touching their baby; this presence was limited by the novel coronavirus disease 2019 (COVID-19)-related restrictions.

CONCLUSION

We highlight stakeholder views on parent involvement and parent-clinician communication in the NICU and note significant overlap with principles of trauma informed care: safety (physical and psychological), trustworthiness and transparency, peer support, collaboration and mutuality, empowerment, and voice and choice. We propose that a greater understanding and implementation of these principles may allow the medical team to more effectively communicate with and involve parents in the care of infants with HIE in the NICU.

KEY POINTS

· Parents of infants with HIE experience trauma both from the birth and the hypothermia treatment.. · Transparent communication and encouraging parental involvement can ameliorate this trauma..

Neuroprotective therapies in the NICU in preterm infants: present and future (Neonatal Neurocritical Care Series)

The survival of preterm infants has steadily improved thanks to advances in perinatal and neonatal intensive clinical care. The focus is now on finding ways to improve morbidities, especially neurological outcomes. Although antenatal steroids and magnesium for preterm infants have become routine therapies, studies have mainly demonstrated short-term benefits for antenatal steroid therapy but limited evidence for impact on long-term neurodevelopmental outcomes. Further advances in neuroprotective and neurorestorative therapies, improved neuromonitoring modalities to optimize recruitment in trials, and improved biomarkers to assess the response to treatment are essential. Among the most promising agents, multipotential stem cells, immunomodulation, and anti-inflammatory therapies can improve neural outcomes in preclinical studies and are the subject of considerable ongoing research. In the meantime, bundles of care protecting and nurturing the brain in the neonatal intensive care unit and beyond should be widely implemented in an effort to limit injury and promote neuroplasticity. IMPACT: With improved survival of preterm infants due to improved antenatal and neonatal care, our focus must now be to improve long-term neurological and neurodevelopmental outcomes. This review details the multifactorial pathogenesis of preterm brain injury and neuroprotective strategies in use at present, including antenatal care, seizure management and non-pharmacological NICU care. We discuss treatment strategies that are being evaluated as potential interventions to improve the neurodevelopmental outcomes of infants born prematurely.

Parents' Experiences of Therapeutic Hypothermia for Neonates With Hypoxic-Ischemic Encephalopathy (HIE): A Single-Center Cross-Sectional Study

BACKGROUND AND OBJECTIVES

The purpose of the study is to assess parental experiences of therapeutic hypothermia for moderate to severe hypoxic-ischemic encephalopathy with the goal of improving local clinical practice guidelines and fostering family-integrated care in neonates with hypoxic-ischemic encephalopathy.

METHODS

This single-center retrospective cross-sectional study included neonates and their parents registered in the Swiss National Asphyxia and Cooling Register between 2011 and 2021. Based on a literature review, an anonymous survey of parents of neonates with hypoxic-ischemic encephalopathy was developed and conducted using an online survey tool. Descriptive statistics were used to analyze the survey results.

RESULTS

The overall response rate to this survey was 64% (46/72). Sufficient information about hypoxic-ischemic encephalopathy was reported by 78% (36/46) of parents and sufficient information about the process of therapeutic hypothermia by 87% (40/46) of parents. The majority of parents indicated the need for, and at least a satisfactory perception of, professional (91%; 42/46) and emotional (87%; 40/46) support. Parents identified fostering family involvement and regular family communication that focuses on family integrated care as areas for improvement.

CONCLUSIONS

There is still an unmet need for multidisciplinary teams to provide professional, empathetic, high quality, and family-integrated care to families with a neonate receiving therapeutic hypothermia for moderate or severe hypoxic-ischemic encephalopathy.

A Review of the Use of Extracellular Vesicles in the Treatment of Neonatal Diseases: Current State and Problems with Translation to the Clinic

Neonatal disorders, particularly those resulting from prematurity, pose a major challenge in health care and have a significant impact on infant mortality and long-term child health. The limitations of current therapeutic strategies emphasize the need for innovative treatments. New cell-free technologies utilizing extracellular vesicles (EVs) offer a compelling opportunity for neonatal therapy by harnessing the inherent regenerative capabilities of EVs. These nanoscale particles, secreted by a variety of organisms including animals, bacteria, fungi and plants, contain a repertoire of bioactive molecules with therapeutic potential. This review aims to provide a comprehensive assessment of the therapeutic effects of EVs and mechanistic insights into EVs from stem cells, biological fluids and non-animal sources, with a focus on common neonatal conditions such as hypoxic-ischemic encephalopathy, respiratory distress syndrome, bronchopulmonary dysplasia and necrotizing enterocolitis. This review summarizes evidence for the therapeutic potential of EVs, analyzes evidence of their mechanisms of action and discusses the challenges associated with the implementation of EV-based therapies in neonatal clinical practice.

Time to Reaching Target Cooling Temperature and 2-year Outcomes in Infants with Hypoxic-Ischemic Encephalopathy

OBJECTIVE

To determine if time to reaching target temperature (TT) is associated with death or neurodevelopmental impairment (NDI) at 2 years of age in infants with hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

Newborn infants ≥36 weeks of gestation diagnosed with moderate or severe HIE and treated with therapeutic hypothermia were stratified based on time at which TT was reached, defined as early (ie, ≤4 hours of age) or late (>4 hours of age). Primary outcomes were death or NDI. Secondary outcomes included neurodevelopmental assessment with Bayley Scales of Infant and Toddler Development, third edition (BSID-III) at age 2.

RESULTS

Among 500 infants, the median time to reaching TT was 4.3 hours (IWR, 3.2-5.7 hours). Infants in early TT group (n = 211 [42%]) compared with the late TT group (n = 289 [58%]) were more likely to be inborn (23% vs 13%; P < .001) and have severe HIE (28% vs 19%; P = .03). The early and late TT groups did not differ in the primary outcome of death or any NDI (adjusted RR, 1.05; 95% CI, 0.85-0.30; P = .62). Among survivors, neurodevelopmental outcomes did not differ significantly in the 2 groups (adjusted mean difference in Bayley Scales of Infant Development-III scores: cognitive, -2.8 [95% CI, -6.1 to 0.5], language -3.3 [95% CI, -7.4 to 0.8], and motor -3.5 [95% CI, -7.3 to 0.3]).

CONCLUSIONS

In infants with HIE, time to reach TT is not independently associated with risk of death or NDI at age 2 years. Among survivors, developmental outcomes are similar between those who reached TT at <4 and ≥4 hours of age.

TRIAL REGISTRATION

High-dose Erythropoietin for Asphyxia and Encephalopathy (HEAL); NCT02811263; https://beta.

CLINICALTRIALS

gov/study/NCT02811263.

Higher parental education was associated with good cognitive outcomes in infants with hypoxic-ischaemic encephalopathy

AIM

Predicting neurodevelopmental outcomes in hypoxic-ischaemic encephalopathy (HIE) remains imprecise, despite advanced imaging and neurophysiological tests. We explored the predictive value of socio-economic status (SES).

METHODS

The cohort comprised 93 infants (59% male) with HIE, who had received therapeutic hypothermia. Patients underwent magnetic resonance imaging, and brain injuries were quantified using the Barkovich scoring system. Family SES was self-reported using a questionnaire. Adverse outcomes were defined as mild to severely delayed development with a score of ≤85 in any domain at 2 years of age, based on the Bayley Scales of Infant Development, Second Edition. Data are presented as odds ratios (OR) with 95% confidence intervals (95% CI).

RESULTS

Multiple regression modelling revealed that higher parental education was strongly associated with good cognitive development, when adjusted for gestational age, serum lactate and brain injuries (OR 2.20, 95% CI 1.16-4.36). The effect size of parental education (β = 0.786) was higher than one score for any brain injury using the Barkovich scoring system (β = -0.356). The literacy environment had a significant effect on cognitive development in the 21 infants who had brain injuries (OR 40, 95% CI 3.70-1352).

CONCLUSION

Parental education and the literacy environment influenced cognitive outcomes in patients with HIE.

Hearing impairment after asphyxia and neonatal encephalopathy: a Norwegian population-based study

The purpose of this study is to evaluate the association between perinatal asphyxia, neonatal encephalopathy, and childhood hearing impairment. This is a population-based study including all Norwegian infants born ≥ 36 weeks gestation between 1999 and 2014 and alive at 2 years (n = 866,232). Data was linked from five national health registries with follow-up through 2019. Perinatal asphyxia was defined as need for neonatal intensive care unit (NICU) admission and an Apgar 5-min score of 4-6 (moderate) or 0-3 (severe). We coined infants with seizures and an Apgar 5-min score < 7 as neonatal encephalopathy with seizures. Infants who received therapeutic hypothermia were considered to have moderate-severe hypoxic-ischemic encephalopathy (HIE). The reference group for comparisons were non-admitted infants with Apgar 5-min score ≥ 7. We used logistic regression models and present data as adjusted odds ratios (aORs) with 95% confidence intervals (CI). The aOR for hearing impairment was increased in all infants admitted to NICU: moderate asphyxia aOR 2.2 (95% CI 1.7-2.9), severe asphyxia aOR 5.2 (95% CI 3.6-7.5), neonatal encephalopathy with seizures aOR 7.0 (95% CI 2.6-19.0), and moderate-severe HIE aOR 10.7 (95% CI 5.3-22.0). However, non-admitted infants with Apgar 5-min scores < 7 did not have increased OR of hearing impairment. The aOR for hearing impairment for individual Apgar 5-min scores in NICU infants increased with decreasing Apgar scores and was 13.6 (95% CI 5.9-31.3) when the score was 0.          Conclusions: An Apgar 5-min score < 7 in combination with NICU admission is an independent risk factor for hearing impairment. Children with moderate-severe HIE had the highest risk for hearing impairment. What is Known: • Perinatal asphyxia and neonatal encephalopathy are associated with an increased risk of hearing impairment. • The strength of the association, and how other co-morbidities affect the risk of hearing impairment, is poorly defined. What is New: • Among neonates admitted to a neonatal intensive care unit (NICU), decreased Apgar 5-min scores, and increased severity of neonatal encephalopathy, were associated with a gradual rise in risk of hearing impairment. • Neonates with an Apgar 5-min score 7, but without NICU admission, did not have an increased risk of hearing impairment.

Altered resting-state functional connectivity in newborns with hypoxic ischemic encephalopathy assessed using high-density functional near-infrared spectroscopy

Hypoxic-ischemic encephalopathy (HIE) results from a lack of oxygen to the brain during the perinatal period. HIE can lead to mortality and various acute and long-term morbidities. Improved bedside monitoring methods are needed to identify biomarkers of brain health. Functional near-infrared spectroscopy (fNIRS) can assess resting-state functional connectivity (RSFC) at the bedside. We acquired resting-state fNIRS data from 21 neonates with HIE (postmenstrual age [PMA] = 39.96), in 19 neonates the scans were acquired post-therapeutic hypothermia (TH), and from 20 term-born healthy newborns (PMA = 39.93). Twelve HIE neonates also underwent resting-state functional magnetic resonance imaging (fMRI) post-TH. RSFC was calculated as correlation coefficients amongst the time courses for fNIRS and fMRI data, respectively. The fNIRS and fMRI RSFC maps were comparable. RSFC patterns were then measured with graph theory metrics and compared between HIE infants and healthy controls. HIE newborns showed significantly increased clustering coefficients, network efficiency and modularity compared to controls. Using a support vector machine algorithm, RSFC features demonstrated good performance in classifying the HIE and healthy newborns in separate groups. Our results indicate the utility of fNIRS-connectivity patterns as potential biomarkers for HIE and fNIRS as a new bedside tool for newborns with HIE.

Neonatal Hypoxic-Ischemic Encephalopathy and Hypothermia Treatment

Neonatal hypoxic-ischemic encephalopathy (HIE) is an important clinical entity because it is associated with death and long-term disability, including cognitive impairment, cerebral palsy, seizures, and neurosensory deficits. Over the past 40 years, there has been an intensive search to identify therapies to improve the prognosis of neonates with HIE. Hypothermia treatment represents the culmination of laboratory investigations including small and large animal studies, followed by pilot human studies, and, finally, randomized controlled trials to establish efficacy and safety. Clinical trials have demonstrated that hypothermia treatment reduces mortality and improves early childhood outcome among survivors. Hypoxic-ischemic encephalopathy is a multi-system disease process that requires intensive medical support for brain monitoring and monitoring of non-central nervous system organ dysfunction. Treatment must be conducted in a level III or IV neonatal intensive care unit with infrastructure for an integrated approach to care for critically ill neonates. Hypothermia treatment is the first and currently the only therapy to improve outcomes for neonates with HIE and indicates that HIE is modifiable. However, outcomes likely can be improved further. Hypothermia treatment has accelerated investigation of other therapies to combine with hypothermia. It has also stimulated a more intensive approach to brain monitoring, which allows earlier intervention for complications. Finally, HIE and hypothermia treatment negatively influences the psychological state of affected families, and there is growing recognition of the importance of trauma-informed principles to guide medical professionals.

Growth and developmental outcomes of infants with hypoxic ischemic encephalopathy

Despite advances in obstetric care, hypoxic ischemic encephalopathy (HIE) remains a significant disease burden. We determined the national trends of HIE prevalence, therapeutic hypothermia (TH) use, mortality, and outcomes from 2012 to 2019. This study included term infants diagnosed with HIE between 2012 and 2019 from the National Health Insurance Service database. The prevalence of HIE was 2.4 per 1000 births without significant change during the period. TH was performed in approximately 6.7% of infants with HIE, and the annual variation ranged from 2.4 to 12.5%. The mortality among all term infants with HIE was 4.6%. The mortality rate among infants with HIE and TH significantly declined from 40 to 16.9% during the eight years. Infants with TH had higher mortality, increased use of inhaled nitric oxide, and more invasive ventilator use, indicating greater disease severity in the TH group. Infants with TH also showed significantly poorer outcomes, including delayed development, cerebral palsy, sensorineural hearing loss, and seizure, compared to infants without TH (p < 0.0001). With the increasing application of TH, mortality and developmental outcomes among infants with HIE have been improving in the past eight years in Korea. Further efforts to improve outcomes should be needed.

Increase in Standardized Management of Neonates with Hypoxic-Ischemic Encephalopathy Since Implementation of a Patient Register

The Swiss National Asphyxia and Cooling Register was implemented in 2011. This study assessed quality indicators of the cooling process and (short-term) outcomes of neonates with hypoxic-ischemic encephalopathy (HIE) receiving therapeutic hypothermia (TH) longitudinally over time in Switzerland. This is a multicenter national retrospective cohort study of prospectively collected register data. Quality indicators were defined for longitudinal comparison (2011-2014 vs. 2015-2018) of processes of TH and (short-term) outcomes of neonates with moderate-to-severe HIE. Five hundred seventy neonates receiving TH in 10 Swiss cooling centers were included (2011-2018). Four hundred forty-nine (449/570; 78.8%) neonates with moderate-to-severe HIE received TH according to the Swiss National Asphyxia and Cooling Register Protocol. Quality indicators of processes of TH improved in 2015-2018 (compared with 2011-2014): less passive cooling (p = 0.013), shorter time to reach target temperature (p = 0.002), and less over- or undercooling (p < 0.001). In 2015-2018, adherence to performing a cranial magnetic resonance imaging after rewarming improved (p < 0.001), whereas less cranial ultrasounds were performed on admission (p = 0.012). With regard to quality indicators of short-term outcomes, persistent pulmonary hypertension of the neonate was reduced (p = 0.003), and there was a trend toward less coagulopathy (p = 0.063) in 2015-2018. There was no statistically significant change in the remaining processes and outcomes. The Swiss National Asphyxia and Cooling Register is well implemented with good overall adherence to the treatment protocol. Management of TH improved longitudinally. Continuous reevaluation of register data is desirable for quality assessment, benchmarking, and maintaining international evidence-based quality standards.

Therapeutic Hypothermia for Hypoxic-Ischemic Brain Injury Is More Effective in Newborn Infants than in Older Patients: Review and Hypotheses

Posthypoxic therapeutic hypothermia has been tested in newborn infants, with seven randomized trials showing consistent evidence of reduction in death, cerebral palsy, and cognitive impairment at school age. In contrast, randomized trials of hypothermia after cardiac arrest in adults have not shown consistent evidence of lasting neurological protection. The apparently greater effectiveness of therapeutic hypothermia in newborns may be due to important biological and clinical differences. One such difference is that adults are heavily colonized with microbes, and many have active inflammatory processes at the time of arrest, but few newborns are heavily colonized or infected at the time of birth. Inflammation can interfere with hypothermia's neuroprotection. A second difference is that apoptosis is more commonly the pathway of neuronal death in newborns than in adults. Hypothermia inhibits apoptosis but not necrosis. Newborns have a larger endogenous supply of stem cells (which reduce apoptosis) than adults and this may favor regeneration and protection from hypothermia and regeneration. A third difference is that immature oligodendroglia are more sensitive to free radical attack then mature oligodendroglia. Hypothermia reduces free radical release. In addition, immature brain has increased N-methyl-D-aspartate receptor subunits compared with adults and hypothermia reduces excitotoxic amino acids. Adults suffering cardiac arrest often have comorbidities such as diabetes, hypertension, and atherosclerosis, which complicate recovery, but newborn infants rarely have comorbidities before asphyxia. Adult hypothermia treatment may have been too short as no trial has cooled for longer than 48 hours, some only 24 or 12 hours, but neonatal therapeutic hypothermia has routinely lasted 72 hours. We hypothesize that this combination of differences favors the effectiveness of therapeutic hypothermia in newborn infants compared with adults.

Association between continuous glucose profile during therapeutic hypothermia and unfavorable outcome in neonates with hypoxic-ischemic encephalopathy209 23-32

BACKGROUND

The detection and management of blood glucose abnormalities in high-risk neonates are crucial for clinical care. The objective of the study was to investigate the continuous glucose profile of hypoxic-ischemic encephalopathy (HIE) patients in the whole-process of therapeutic hypothermia (TH) and its association with clinical and neurological outcomes.

METHOD

In this single-center retrospective study, HIE patients who received both TH and continuous glucose monitoring (CGM) were recruited from March 2016 to September 2021.

RESULTS

Of 47 neonates recruited, 24 had unfavorable outcome. Dysglycemia was most prevalent in the first 24 h of TH, among which hyperglycemia occurred more frequently. CGM showed that the duration, episodes and area under curve (AUC) of hypoglycemia were statistically different in neonates with different outcomes. The occurrence, longer duration, greater AUC of hypoglycemia and an early high coefficient of variation (CV%, CV = SD/mean) were associated with unfavorable outcomes (aOR 26.55 [2.02-348.5], aOR 2.11 [1.08-4.14], aOR 1.80 [1.11-2.91] and aOR respectively), while hyperglycemia was not.

CONCLUSION

During the whole process of TH, hypoglycemia and early unstable glycemic variability were strongly associated with unfavorable outcomes. CGM can instantly detect dysglycemia and facilitate precise glucose management in HIE neonates.

The critical role of technologies in neonatal care

Neonatal care has made significant advances in the last few decades. As a result, mortality and morbidity in high-risk infants, such as extremely preterm infants or those infants with birth-related brain injury, has reduced significantly. Many of these advances have been facilitated or delivered through development of medical technologies allowing clinical teams to be better supported with the care they deliver or provide new therapies and diagnostics to improve management. The delivery of neonatal intensive care requires the provision of medical technologies that are easy to use, reliable, accurate and ideally developed for the unique needs of the newborn population. Many technologies have been developed and commercialised following adult trials without ever being studied in neonatal patients despite the unique characteristics of this population. Increasingly, funders and industry are recognising this major challenge which has resulted in initiatives to develop new ideas from concept through to clinical care. This review explores some of the key medical technologies used in neonatal care and the evidence to support their adoption to improve outcomes. A number of devices have yet to realise their full potential and will require further development to optimise and find their ideal target population and clinical benefit. Examples of emerging technologies, which may soon become more widely used, are also discussed. As neonatal care relies more on medical technologies, we need to be aware of the impact on care pathways, especially from a human factors approach, the associated costs and subsequent benefits to patients alongside the supporting evidence.

Hypothermia combined with extracellular vesicles from clonally expanded immortalized mesenchymal stromal cells improves neurodevelopmental impairment in neonatal hypoxic-ischemic brain injury

BACKGROUND

Neonatal encephalopathy following hypoxia-ischemia (HI) is a leading cause of childhood death and morbidity. Hypothermia (HT), the only available but obligatory therapy is limited due to a short therapeutic window and limited efficacy. An adjuvant therapy overcoming limitations of HT is still missing. Mesenchymal stromal cell (MSC)-derived extracellular vesicles (EVs) have shown promising therapeutic effects in various brain injury models. Challenges associated with MSCs' heterogeneity and senescence can be mitigated by the use of EVs from clonally expanded immortalized MSCs (ciMSCs). In the present study, we hypothesized that intranasal ciMSC-EV delivery overcomes limitations of HT.

METHODS

Nine-day-old C57BL/6 mice were exposed to HI by occlusion of the right common carotid artery followed by 1 h hypoxia (10% oxygen). HT was initiated immediately after insult for 4 h. Control animals were kept at physiological body core temperatures. ciMSC-EVs or vehicle were administered intranasally 1, 3 and 5 days post HI/HT. Neuronal cell loss, inflammatory and regenerative responses were assessed via immunohistochemistry, western blot and real-time PCR 7 days after insult. Long-term neurodevelopmental outcome was evaluated by analyses of cognitive function, activity and anxiety-related behavior 5 weeks after HI/HT.

RESULTS

In contrast to HT monotherapy, the additional intranasal therapy with ciMSC-EVs prevented HI-induced cognitive deficits, hyperactivity and alterations of anxiety-related behavior at adolescence. This was preceded by reduction of striatal neuronal loss, decreased endothelial, microglia and astrocyte activation; reduced expression of pro-inflammatory and increased expression of anti-inflammatory cytokines. Furthermore, the combination of HT with intranasal ciMSC-EV delivery promoted regenerative and neurodevelopmental processes, including endothelial proliferation, neurotrophic growth factor expression and oligodendrocyte maturation, which were not altered by HT monotherapy.

CONCLUSION

Intranasal delivery of ciMSC-EVs represents a novel adjunct therapy, overcoming limitations of acute HT thereby offering new possibilities for improving long-term outcomes in neonates with HI-induced brain injury.

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

Background

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

Methods

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

Findings

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

Interpretation

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

Funding

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

Rapid, selective and homogeneous brain cooling with transnasal flow of ambient air for pediatric resuscitation

Neurologic outcome from out-of-hospital pediatric cardiac arrest remains poor. Although therapeutic hypothermia has been attempted in this patient population, a beneficial effect has yet to be demonstrated, possibly because of the delay in achieving target temperature. To minimize this delay, we developed a simple technique of transnasal cooling. Air at ambient temperature is passed through standard nasal cannula with an open mouth to produce evaporative cooling of the nasal passages. We evaluated efficacy of brain cooling with different airflows in different size piglets. Brain temperature decreased by 3°C within 25 minutes with nasal airflow rates of 16, 32, and 16 L/min in 1.8-, 4-, and 15-kg piglets, respectively, whereas rectal temperature lagged brain temperature. No substantial spatial temperature gradients were seen along the neuroaxis, suggesting that heat transfer is via blood convection. The evaporative cooling did not reduce nasal turbinate blood flow or sagittal sinus oxygenation. The rapid and selective brain cooling indicates a high humidifying capacity of the nasal turbinates is present early in life. Because of its simplicity, portability, and low cost, transnasal cooling potentially could be deployed in the field for early initiation of brain cooling prior to maintenance with standard surface cooling after pediatric cardiac arrest.

Early assessment of injury with optical markers in a piglet model of neonatal encephalopathy

BACKGROUND

Opportunities for adjunct therapies with cooling in neonatal encephalopathy are imminent; however, robust biomarkers of early assessment are lacking. Using an optical platform of broadband near-infrared spectroscopy and diffuse correlation spectroscopy to directly measure mitochondrial metabolism (oxCCO), oxygenation (HbD), cerebral blood flow (CBF), we hypothesised optical indices early (1-h post insult) after hypoxia-ischaemia (HI) predicts insult severity and outcome.

METHODS

Nineteen newborn large white piglets underwent continuous neuromonitoring as controls or following moderate or severe HI. Optical indices were expressed as mean semblance (phase difference) and coherence (spectral similarity) between signals using wavelet analysis. Outcome markers included the lactate/N-acetyl aspartate (Lac/NAA) ratio at 6 h on proton MRS and TUNEL cell count.

RESULTS

CBF-HbD semblance (cerebrovascular dysfunction) correlated with BGT and white matter (WM) Lac/NAA (r2 = 0.46, p = 0.004, r2 = 0.45, p = 0.004, respectively), TUNEL cell count (r2 = 0.34, p = 0.02) and predicted both initial insult (r2 = 0.62, p = 0.002) and outcome group (r2 = 0.65 p = 0.003). oxCCO-HbD semblance (cerebral metabolic dysfunction) correlated with BGT and WM Lac/NAA (r2 = 0.34, p = 0.01 and r2 = 0.46, p = 0.002, respectively) and differentiated between outcome groups (r2 = 0.43, p = 0.01).

CONCLUSION

Optical markers of both cerebral metabolic and vascular dysfunction 1 h after HI predicted injury severity and subsequent outcome in a pre-clinical model.

IMPACT

This study highlights the possibility of using non-invasive optical biomarkers for early assessment of injury severity following neonatal encephalopathy, relating to the outcome. Continuous cot-side monitoring of these optical markers can be useful for disease stratification in the clinical population and for identifying infants who might benefit from future adjunct neuroprotective therapies beyond cooling.

Progress in the treatment of neonatal hypoxic-ischemic encephalopathy with umbilical cord blood mononuclear cells

Neonatal hypoxic-ischemic encephalopathy (HIE) is a common disease among newborns, which is a leading cause of neonatal death and permanent neurological sequelae. Therapeutic hypothermia (TH) is the only method for the treatment of HIE that has been recognized effective clinically at home and abroad, but the efficacy is limited. Recent research suggests that the cord blood-derived mononuclear cells (CB-MNCs), which the refer to blood cells containing one nucleus in the cord blood, exert anti-oxidative, anti-inflammatory, anti-apoptotic effects and play a neuroprotective role in HIE. This review focuses on safety and efficacy, the route of administration, dose, timing and combination treatment of CB-MNCs in HIE.

Remote Monitoring for Seizures During Therapeutic Hypothermia in Neonates With Hypoxic-Ischemic Encephalopathy

Importance

Neonates with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH) frequently experience seizures, which are associated with adverse outcomes. Efforts to rapidly identify seizures and reduce seizure burden may positively change neurologic and neurodevelopmental outcomes.

Objective

To describe the onset, treatment, and evolution of seizures in a large cohort of newborns with HIE during TH assisted by a telehealth model and remote neuromonitoring approach.

Design, Setting, and Participants

This was a prospective, observational, multicenter cohort study performed between July 2017 and December 2021 in 32 hospitals in Brazil. Participants were newborns with HIE meeting eligibility criteria and receiving TH. Data were analyzed from November 2022 to April 2023.

Exposure

Infants with HIE receiving TH were remotely monitored with 3-channel amplitude-integrated electroencephalography (aEEG) including raw tracing and video imaging, and bedside clinicians received assistance from trained neonatologists and neurologists.

Main Outcomes and Measures

Data on modified Sarnat examination, presence, timing and seizure type, aEEG background activity, sleep-wake cycling, and antiepileptic drugs used were collected. Descriptive statistical analysis was used with independent t test, χ2, Mann-Whitney test, and post hoc analyses applied for associations.

Results

A total of 872 cooled newborns were enrolled; the median (IQR) gestational age was 39 (38-40) weeks, 518 (59.4%) were male, and 59 (6.8%) were classified as having mild encephalopathy by modified Sarnat examination, 504 (57.8%) as moderate, and 180 (20.6%) as severe. Electrographic seizures were identified in 296 newborns (33.9%), being only electrographic in 213 (71.9%) and clinical followed by electroclinical uncoupling in 50 (16.9%). Early abnormal background activity had a significant association with seizures. Infants with flat trace had the highest rate of seizures (58 infants [68.2%]) and the greatest association with the incidence of seizures (odds ratio [OR], 12.90; 95% CI, 7.57-22.22) compared with continuous normal voltage. The absence of sleep-wake cycling was also associated with a higher occurrence of seizures (OR, 2.22; 95% CI, 1.67-2.96). Seizure onset was most frequent between 6 and 24 hours of life (181 infants [61.1%]); however, seizure occurred in 34 infants (11.5%) during rewarming. A single antiepileptic drug controlled seizures in 192 infants (64.9%). The first line antiepileptic drug was phenobarbital in 294 (99.3%).

Conclusions and Relevance

In this cohort study of newborns with HIE treated with TH, electrographic seizure activity occurred in 296 infants (33.9%) and was predominantly electrographic. Seizure control was obtained with a single antiepileptic drug in 192 infants (64.9%). These findings suggest neonatal neurocritical care can be delivered at remote limited resource hospitals due to innovations in technology and telehealth.

The association of placental pathology and neurodevelopmental outcomes in patients with neonatal encephalopathy

BACKGROUND

Studies conflict on how acute versus chronic placental pathology impacts outcomes after neonatal encephalopathy from presumed hypoxic-ischemic encephalopathy (HIE). We examine how outcomes after presumed HIE vary by placental pathology categories.

METHODS

We performed retrospective chart review for neonates with presumed HIE, regardless of severity, focusing on 50 triads for whom placental specimens were available for re-review. Placentas were categorized as having only acute, any chronic, or no lesions. Primary outcomes included in-hospital morbidity/mortality and long-term neurodevelopmental symptoms. Secondary outcomes assessed neonatal MRI and EEG.

RESULTS

Demographics did not differ between groups. Forty-seven neonates were treated with therapeutic hypothermia. Placental acuity category was not associated with primary or secondary outcomes, but clinical and/or histopathological chorioamnionitis was associated with abnormal EEG background and post-neonatal epilepsy (16.7%, n = 3 with chorioamnionitis versus 0%, n = 0 without chorioamnionitis, p = 0.04).

CONCLUSIONS

When grouped by acute, chronic, or absent placental lesions, we observed no association with in-hospital, neurodevelopmental, MRI, or EEG outcomes. When reanalyzed by the presence of chorioamnionitis, we found that chorioamnionitis appeared to be associated with a higher risk of EEG alterations and post-neonatal epilepsy. Despite our limited sample size, our results emphasize the critical role of placental examination for neuroprognostication in presumed HIE.

IMPACT

Neonatal encephalopathy presumed to result from impaired fetal cerebral oxygenation or blood flow is called hypoxic ischemic encephalopathy (HIE). Prior studies link placental pathology to various outcomes after HIE but disagree on the impact of acute versus chronic pathology. Our study determines that neurodevelopmental outcomes, in-hospital outcomes, injury on MRI, and EEG findings in patients with HIE are not differentially associated with acute versus chronic placental pathology. Chorioamnionitis is associated with an increased risk of abnormal EEG patterns and post-neonatal epilepsy. Histopathologic chorioamnionitis without clinical symptoms is common in HIE, emphasizing the crucial role of placental pathology for neuroprognostication.

Long-term motor development after hypothermia-treated hypoxic-ischaemic encephalopathy

AIMS

To describe longitudinal motor development in children treated with therapeutic- hypothermia (TH) due to neonatal hypoxic-ischaemic encephalopathy (HIE) and to explore motor functioning in early adolescence.

MATERIAL AND METHODS

Children treated with TH due to HIE during 2007-2009, in Stockholm, participated in a prospective follow-up study. Motor development was assessed on four occasions, reported as percentiles and at mean ages. Alberta Infant Motor Scale was used at 0.35 years of age, Bayley Scales of Infant and Toddler Development-III at 2.1 years and Movement Assessment Battery for Children (MABC-2) at 7.3 and 11.1 years of age. MABC-2 Checklist was completed by parents at 7.3 and 11.1 years of age. General cognition was assessed using Wechsler Intelligence Scales for Children Fifth Edition (WISC-V).

RESULTS

Thirty-one percent (14/45) of the children had a motor score ≤ 15th percentile, indicating risk of motor difficulties at 11.1 years of age, and simultaneously the scores from parents of 52% (23/44), indicating risk of motor difficulties in the everyday context. These children had significantly lower motor percentile at 2.1 years of age, but within the normal range. Longitudinal motor development displayed a weak association with WISC-V Full Scale IQ (rs0.38, p = 0.013).

CONCLUSION

Among survivors of hypothermia-treated HIE free of moderate/severe cerebral palsy, a third had MABC-2 scores indicating risk of motor difficulties at 11.1 years of age. As motor difficulties became more apparent over time, we suggest that children treated with TH due to neonatal HIE should be followed into at least middle school age.

Hypothermic Protection in Neocortex Is Topographic and Laminar, Seizure Unmitigating, and Partially Rescues Neurons Depleted of RNA Splicing Protein Rbfox3/NeuN in Neonatal Hypoxic-Ischemic Male Piglets

The effects of hypothermia on neonatal encephalopathy may vary topographically and cytopathologically in the neocortex with manifestations potentially influenced by seizures that alter the severity, distribution, and type of neuropathology. We developed a neonatal piglet survival model of hypoxic-ischemic (HI) encephalopathy and hypothermia (HT) with continuous electroencephalography (cEEG) for seizures. Neonatal male piglets received HI-normothermia (NT), HI-HT, sham-NT, or sham-HT treatments. Randomized unmedicated sham and HI piglets underwent cEEG during recovery. Survival was 2-7 days. Normal and pathological neurons were counted in different neocortical areas, identified by cytoarchitecture and connectomics, using hematoxylin and eosin staining and immunohistochemistry for RNA-binding FOX-1 homolog 3 (Rbfox3/NeuN). Seizure burden was determined. HI-NT piglets had a reduced normal/total neuron ratio and increased ischemic-necrotic/total neuron ratio relative to sham-NT and sham-HT piglets with differing severities in the anterior and posterior motor, somatosensory, and frontal cortices. Neocortical neuropathology was attenuated by HT. HT protection was prominent in layer III of the inferior parietal cortex. Rbfox3 immunoreactivity distinguished cortical neurons as: Rbfox3-positive/normal, Rbfox3-positive/ischemic-necrotic, and Rbfox3-depleted. HI piglets had an increased Rbfox3-depleted/total neuron ratio in layers II and III compared to sham-NT piglets. Neuronal Rbfox3 depletion was partly rescued by HT. Seizure burdens in HI-NT and HI-HT piglets were similar. We conclude that the neonatal HI piglet neocortex has: (1) suprasylvian vulnerability to HI and seizures; (2) a limited neuronal cytopathological repertoire in functionally different regions that engages protective mechanisms with HT; (3) higher seizure burden, insensitive to HT, that is correlated with more panlaminar ischemic-necrotic neurons in the somatosensory cortex; and (4) pathological RNA splicing protein nuclear depletion that is sensitive to HT. This work demonstrates that HT protection of the neocortex in neonatal HI is topographic and laminar, seizure unmitigating, and restores neuronal depletion of RNA splicing factor.

Bladder Temperature During Neonatal Targeted Temperature Management: A Case Report

BACKGROUND

Neonatal encephalopathy is a clinical condition of altered neurological function in the first days of life. Targeted temperature management (TTM) is a validated approach to mitigate neurologic sequelae. Current literature suggests using rectal or esophageal site to assess temperature during TTM, but few studies focused on the best and the less invasive site to evaluate the temperature. This case report describes the performance of the bladder temperature monitoring during TTM.

CLINICAL FINDINGS

A female newborn was born at 39 weeks' gestational age plus 4 days. At delivery, the newborn was in cardiorespiratory arrest.

PRIMARY DIAGNOSIS

After performing cardiopulmonary resuscitation and neurological examination, a hypoxic-ischemic encephalopathy was diagnosed.

INTERVENTIONS

After about 2 hours from birth, the newborn underwent TTM.

OUTCOMES

A total of 4642 measurements of rectal temperature and 4520 measurements of bladder temperature were collected. Agreement between the 2 sites was statistically significant with a mean difference of 0.064°C ± 0.219 (95% confidence interval, -0.364 to 0.494); F = 47.044; and P value of less than .001. Furthermore, difference between rectal and bladder sites was not influenced by patient's urine output ( F = 0.092, P = .762).

PRACTICE RECOMMENDATIONS

Bladder temperature seems to have a good reliability and not to be inferior to the other assessment site currently used. Using bladder catheter with temperature sensor could reduce the number of devices, ensure safer stabilization, and decrease treatment downtime.