Neonatal Encephalopathy: Need for Recognition of Multiple Etiologies for Optimal Management

Clinical exome sequencing uncovers genetic disorders in neonates with suspected hypoxic-ischemic encephalopathy: A retrospective analysis

Hypoxic-ischemic encephalopathy (HIE) occurs in up to 7 out of 1000 births and accounts for almost a quarter of neonatal deaths worldwide. Despite the name, many newborns with HIE have little evidence of perinatal hypoxia. We hypothesized that some infants with HIE have genetic disorders that resemble encephalopathy. We reviewed genetic results for newborns with HIE undergoing exome or genome sequencing at a clinical laboratory (2014-2022). Neonates were included if they had a diagnosis of HIE and were delivered ≥35 weeks. Neonates were excluded for cardiopulmonary pathology resulting in hypoxemia or if neuroimaging suggested postnatal hypoxic-ischemic injury. Of 24 patients meeting inclusion criteria, six (25%) were diagnosed with a genetic condition. Four neonates had variants at loci linked to conditions with phenotypic features resembling HIE, including KIF1A, GBE1, ACTA1, and a 15q13.3 deletion. Two additional neonates had variants in genes not previously associated with encephalopathy, including DUOX2 and PTPN11. Of the six neonates with a molecular diagnosis, two had isolated HIE without apparent comorbidities to suggest a genetic disorder. Genetic diagnoses were identified among neonates with and without sentinel labor events, abnormal umbilical cord gasses, and low Apgar scores. These results suggest that genetic evaluation is clinically relevant for patients with perinatal HIE.

Consensus definition and diagnostic criteria for neonatal encephalopathy-study protocol for a real-time modified delphi study

BACKGROUND

'Neonatal encephalopathy' (NE) describes a group of conditions in term infants presenting in the earliest days after birth with disturbed neurological function of cerebral origin. NE is aetiologically heterogenous; one cause is peripartum hypoxic ischaemia. Lack of uniformity in the terminology used to describe NE and its diagnostic criteria creates difficulty in the design and interpretation of research and complicates communication with families. The DEFINE study aims to use a modified Delphi approach to form a consensus definition for NE, and diagnostic criteria.

METHODS

Directed by an international steering group, we will conduct a systematic review of the literature to assess the terminology used in trials of NE, and with their guidance perform an online Real-time Delphi survey to develop a consensus diagnosis and criteria for NE. A consensus meeting will be held to agree on the final terminology and criteria, and the outcome disseminated widely.

DISCUSSION

A clear and consistent consensus-based definition of NE and criteria for its diagnosis, achieved by use of a modified Delphi technique, will enable more comparability of research results and improved communication among professionals and with families.

IMPACT

The terms Neonatal Encephalopathy and Hypoxic Ischaemic Encephalopathy tend to be used interchangeably in the literature to describe a term newborn with signs of encephalopathy at birth. This creates difficulty in communication with families and carers, and between medical professionals and researchers, as well as creating difficulty with performance of research. The DEFINE project will use a Real-time Delphi approach to create a consensus definition for the term 'Neonatal Encephalopathy'. A definition formed by this consensus approach will be accepted and utilised by the neonatal community to improve research, outcomes, and parental experience.

Parental impact during and after neonatal intensive care admission

Parents play a pivotal role in neurodevelopmental outcomes of their children in the neonatal intensive care unit (NICU) and beyond. Integration of parents in clinical care and research is synergistic. Engaged parents yield more comprehensive clinical care and more robust and meaningful research products. Subsequently, successful clinical and research efforts improve outcomes for children. We review strategies for parental integration into NICU clinical care and research, including parental involvement in therapeutic interventions and neurodevelopmental care, and effective communication strategies for clinicians and researchers. We discuss challenges in neonatal trials and emphasize the need for building a culture of research, collaborative partnerships with patient advocacy organizations, and ongoing support beyond the NICU. Overall, we call for recognizing and fostering the impactful role of parents as teammates with clinicians and researchers in optimizing neurodevelopmental outcomes in the NICU and beyond.

Ultrasound Diagnosis and Near-Infrared Spectroscopy in the Study of Encephalopathy in Neonates Born under Asphyxia: Narrative Review

Brain injury resulting from adverse events during pregnancy and delivery is the leading cause of neonatal morbidity and disability. Surviving neonates often suffer long-term motor, sensory, and cognitive impairments. Birth asphyxia is among the most common causes of neonatal encephalopathy. The integration of ultrasound, including Doppler ultrasound, and near-infrared spectroscopy (NIRS) offers a promising approach to understanding the pathology and diagnosis of encephalopathy in this special patient population. Ultrasound diagnosis can be very helpful for the assessment of structural abnormalities associated with neonatal encephalopathy such as alterations in brain structures (intraventricular hemorrhage, infarcts, hydrocephalus, white matter injury) and evaluation of morphologic changes. Doppler sonography is the most valuable method as it provides information about blood flow patterns and outcome prediction. NIRS provides valuable insight into the functional aspects of brain activity by measuring tissue oxygenation and blood flow. The combination of ultrasonography and NIRS may produce complementary information on structural and functional aspects of the brain. This review summarizes the current state of research, discusses advantages and limitations, and explores future directions to improve applicability and efficacy.

Role of next generation sequencing in diagnosis and management of critically ill children with suspected monogenic disorder

Next generation sequencing based diagnosis has emerged as a promising tool for evaluating critically ill neonates and children. However, there is limited data on its utility in developing countries. We assessed its diagnostic rate and clinical impact on management of pediatric patients with a suspected genetic disorder requiring critical care. The study was conducted at a single tertiary hospital in Northern India. We analyzed 70 children with an illness requiring intensive care and obtained a precise molecular diagnosis in 32 of 70 probands (45.3%) using diverse sequencing techniques such as clinical exome, whole exome, and whole genome. A significant change in clinical outcome was observed in 13 of 32 (40.6%) diagnosed probands with a change in medication in 11 subjects and redirection to palliative care in two subjects. Additional benefits included specific dietary management (three cases), avoidance of a major procedure (one case) and better reproductive counseling. Dramatic therapeutic responses were observed in three cases with SCN1A, SCN2A and KCNQ2-related epileptic encephalopathy. A delayed turn-around for sequencing results was perceived as a major limiting factor in the study, as rapid and ultra-rapid sequencing was not available. Achieving a precise molecular diagnosis has great utility in managing critically ill patients with suspected genetic disorders in developing countries.

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.

COHESION: a core outcome set for the treatment of neonatal encephalopathy

BACKGROUND

Heterogeneity in outcomes reported in trials of interventions for the treatment of neonatal encephalopathy (NE) makes evaluating the effectiveness of treatments difficult. Developing a core outcome set for NE treatment would enable researchers to measure and report the same outcomes in future trials. This would minimise waste, ensure relevant outcomes are measured and enable evidence synthesis. Therefore, we aimed to develop a core outcome set for treating NE.

METHODS

Outcomes identified from a systematic review of the literature and interviews with parents were prioritised by stakeholders (n = 99 parents/caregivers, n = 101 healthcare providers, and n = 22 researchers/ academics) in online Delphi surveys. Agreement on the outcomes was achieved at online consensus meetings attended by n = 10 parents, n = 18 healthcare providers, and n = 13 researchers/ academics.

RESULTS

Seven outcomes were included in the final core outcome set: survival; brain injury on imaging; neurological status at discharge; cerebral palsy; general cognitive ability; quality of life of the child, and adverse events related to treatment.

CONCLUSION

We developed a core outcome set for the treatment of NE. This will allow future trials to measure and report the same outcomes and ensure results can be compared. Future work should identify how best to measure the COS.

IMPACT

We have identified seven outcomes that should be measured and reported in all studies for the treatment of neonatal encephalopathy. Previously, a core outcome set for neonatal encephalopathy treatments did not exist. This will help to reduce heterogeneity in outcomes reported in clinical trials and other studies, and help researchers identify the best treatments for neonatal encephalopathy.

Temporal evolution of electrographic seizures in newborn infants with hypoxic-ischaemic encephalopathy requiring therapeutic hypothermia: a secondary analysis of the ANSeR studies

BACKGROUND

Despite extensive research on neonatal hypoxic-ischaemic encephalopathy, detailed information about electrographic seizures during active cooling and rewarming of therapeutic hypothermia is sparse. We aimed to describe temporal evolution of seizures and determine whether there is a correlation of seizure evolution with 2-year outcome.

METHODS

This secondary analysis included newborn infants recruited from eight European tertiary neonatal intensive care units for two multicentre studies (a randomised controlled trial [NCT02431780] and an observational study [NCT02160171]). Infants were born at 36+0 weeks of gestation with moderate or severe hypoxic-ischaemic encephalopathy and underwent therapeutic hypothermia with prolonged conventional video-electroencephalography (EEG) monitoring for 10 h or longer from the start of rewarming. Seizure burden characteristics were calculated based on electrographic seizures annotations: hourly seizure burden (minutes of seizures within an hour) and total seizure burden (minutes of seizures within the entire recording). We categorised infants into those with electrographic seizures during active cooling only, those with electrographic seizures during cooling and rewarming, and those without seizures. Neurodevelopmental outcomes were determined using the Bayley's Scales of Infant and Toddler Development, Third Edition (BSID-III), the Griffiths Mental Development Scales (GMDS), or neurological assessment. An abnormal outcome was defined as death or neurodisability at 2 years. Neurodisability was defined as a composite score of 85 or less on any subscales for BSID-III, a total score of 87 or less for GMDS, or a diagnosis of cerebral palsy (dyskinetic cerebral palsy, spastic quadriplegia, or mixed motor impairment) or epilepsy.

FINDINGS

Of 263 infants recruited between Jan 1, 2011, and Feb 7, 2017, we included 129 infants: 65 had electrographic seizures (43 during active cooling only and 22 during and after active cooling) and 64 had no seizures. Compared with infants with seizures during active cooling only, those with seizures during and after active cooling had a longer seizure period (median 12 h [IQR 3-28] vs 68 h [35-86], p<0·0001), more seizures (median 12 [IQR 5-36] vs 94 [24-134], p<0·0001), and higher total seizure burden (median 69 min [IQR 22-104] vs 167 min [54-275], p=0·0033). Hourly seizure burden peaked at about 20-24 h in both groups, and infants with seizures during and after active cooling had a secondary peak at 85 h of age. When combined, worse EEG background (major abnormalities and inactive background) at 12 h and 24 h were associated with the seizure group: compared with infants with a better EEG background (normal, mild, or moderate abnormalities), infants with a worse EEG background were more likely to have seizures after cooling at 12 h (13 [54%] of 24 vs four [14%] of 28; odds ratio 7·09 [95% CI 1·88-26·77], p=0·0039) and 24 h (14 [56%] of 25 vs seven [18%] of 38; 5·64 [1·81-17·60], p=0·0029). There was a significant relationship between EEG grade at 12 h (four categories) and seizure group (p=0·020). High total seizure burden was associated with increased odds of an abnormal outcome at 2 years of age (odds ratio 1·007 [95% CI 1·000-1·014], p=0·046), with a medium negative correlation between total seizure burden and BSID-III cognitive score (rS=-0·477, p=0·014, n=26).

INTERPRETATION

Overall, half of infants with hypoxic-ischaemic encephalopathy had electrographic seizures and a third of those infants had seizures beyond active cooling, with worse outcomes. These results raise the importance of prolonged EEG monitoring of newborn infants with hypoxic-ischaemic encephalopathy not only during active cooling but throughout the rewarming phase and even longer when seizures are detected.

FUNDING

Wellcome Trust, Science Foundation Ireland, and the Irish Health Research Board.

The net impact of clinical seizures on outcome characteristics in infants with neonatal encephalopathies at 12 months of age

PURPOSE

To assess the impact of clinical neonatal seizures on outcome characteristics of preterm and term newborns with neonatal encephalopathy (NE).

METHODS

We designed a prospective comparative study with 53 babies (preterm neonates: 26 and term neonates: 27) with NE: group 1 (preterm neonates with seizures, n = 13), group 2 (preterm neonates without seizures, n = 13), group 3 (term neonates with seizures, n = 13) and group 4 (term neonates without seizures, n = 14). The functional outcome characteristics of the survivors were assessed by the Ankara Developmental Screening Inventory (ADSI) and the Guide for Monitoring Child Development (GMCD) at 12 months of age.

RESULTS

Clinically defined acute symptomatic seizures were diagnosed with prompt conventional EEG / amplitude-integrated EEG in preterm (92.3%) and term neonates (81.4%) with etiology-specific diagnoses of NE. There were no differences between the study groups regarding seizure semiology and EEG characteristics. A primary adverse outcome was defined in 22 (41.5%) of the cohort. However, only 15.3% of infants had an unfavorable functional outcome with ADSI at 12 months. Among the survivors, there was no significant difference between the study groups regarding ADSI scores. The GMDC test revealed normal development in 50% of survivors with seizures in the preterm group and 83% in the term group.

CONCLUSION

There was no significant difference between the characteristics of functional outcomes at 12 months in preterm and term neonates with NE for clinical seizures.

Mimickers of hypoxic-ischaemic brain injury in term neonates: What the radiologist should know

Patterns of neonatal hypoxic-ischaemic brain injury (HIBI) are fairly well known. There are, however, other diagnoses with imaging patterns that may mimic HIBI. A review of MRI studies was conducted for children with suspected cerebral palsy, correlated with prior imaging, clinical details and laboratory tests where available. In the 63 identified cases, imaging features were, in many cases, very similar to the known patterns of HIBI. The alternative diagnoses can be classified as developmental, vascular, chromosomal, infections, metabolic disorders, and congenital syndromes. These findings are described in this pictorial essay. The potential mimickers of HIBI described in this essay can demonstrate similar imaging appearances to HIBI.

Contribution

There are multiple possible causes of neonatal encephalopathy other than hypoxic-ischaemic encephalopathy. Many conditions may mimic HIBI, each of which can be associated with significant morbidity. It is prudent for the reporting radiologist to be aware of these alternate clinico-radiological diagnoses.

Newly discovered variants in unexplained neonatal encephalopathy

BACKGROUND

The genetic background of neonatal encephalopathy (NE) is complicated and early diagnosis is beneficial to optimizing therapeutic strategy for patients.

METHODS

NE Patients with unclear etiology received regular clinical tests including ammonia test, metabolic screening test, amplitude-integrated electroencephalographic (aEEG) monitoring, brain Magnetic Resonance Imaging (MRI) scanning, and genetic test. The protein structure change was predicted using Dynamut2 and RoseTTAFold.

RESULTS

15 out of a total of 113 NE Patients were detected with newly reported pathogenic variants. In this sub-cohort, (1) seizure was the primary initial symptoms; (2) four patients had abnormal metabolic screening results, and two of them were also diagnosed with excessive blood ammonia concentration; (3) the brain MRI results were irregular in three infants and the brain waves were of moderate-severe abnormality in about a half of the patients. The novel pathogenic variants discovered in this study belonged to 12 genes, and seven of them were predicted to introduce a premature translation termination. In-silicon predictions showed that four variants were destructive to the protein structure of KCNQ2.

CONCLUSION

Our study expands the mutation spectrum of genes associated with NE and introduces new evidence for molecular diagnosis in this newborn illness.

A Call for Early Detection of Cerebral Palsy

Cerebral palsy (CP) is the most common physical disability across the lifespan, but historically, CP has not been diagnosed before the age of 2 years. Barriers to early diagnosis ranged from lack of available biomarkers, absence of curative treatments, perceived stigma associated with a lifelong diagnosis, and a desire to rule out other diagnoses first. Most importantly, the fundamental question that remained was whether children would benefit from earlier detection and intervention given the paucity of research. However, evidence-based guidelines published in 2017 demonstrated that the General Movements Assessment, the Hammersmith Infant Neurological Examination, and neuroimaging can be combined with other elements such as a clinical history and standardized motor assessments to provide the highest predictive value for diagnosing CP as early as age 3 months in high-risk newborns. Implementation of these guidelines has been successful in decreasing the age at CP diagnosis, particularly in high-risk infant follow-up clinics with expertise in performing these assessments. Early detection of CP allows for clinical and research opportunities investigating earlier interventions during a critical period of neuroplasticity, with the goal of improving developmental trajectories for children and their families. New guidelines and research are now being developed with a focus on early, targeted interventions that continue to be studied, along with global detection initiatives.

The Placenta and Neonatal Encephalopathy with a Focus on Hypoxic-Ischemic Encephalopathy

Background: Placental examination is important for its diagnostic immediacy to correlate with maternal and/or fetal complications and parturitional difficulties. In a broader context, clinicopathologic studies of the placenta have addressed a range of pathogenetic questions that have led to conclusive and inconclusive results and interpretations. Methods: Recent standardized morphologic criteria and terminology of placental lesions have facilitated the ability to compare findings from studies that have focused on complications and outcomes of pregnancy. This review is an evaluation of recent studies on placental lesions associated with hypoxic-ischemic encephalopathy (HIE). Conclusion: No apparent consensus exists on whether it is fetal inflammation with the release of cytokines or chronic maternal and/or fetal vascular malperfusion is responsible for HIE with a lowering of the threshold for hypoxic ischemia. The counter argument is that HIE occurs solely as an intrapartum event. Additional investigation is necessary.

Sex differences in neonatal brain injury and inflammation

Neonatal brain injury and associated inflammation is more common in males. There is a well-recognised difference in incidence and outcome of neonatal encephalopathy according to sex with a pronounced male disadvantage. Neurodevelopmental differences manifest from an early age in infancy with females having a lower incidence of developmental delay and learning difficulties in comparison with males and male sex has consistently been identified as a risk factor for cerebral palsy in epidemiological studies. Important neurobiological differences exist between the sexes with respect to neuronal injury which are especially pronounced in preterm neonates. There are many potential reasons for these sex differences including genetic, immunological and hormonal differences but there are limited studies of neonatal immune response. Animal models with induced neonatal hypoxia have shown various sex differences including an upregulated immune response and increased microglial activation in males. Male sex is recognized to be a risk factor for neonatal hypoxic ischemic encephalopathy (HIE) during the perinatal period and this review discusses in detail the sex differences in brain injury in preterm and term neonates and some of the potential new therapies with possible sex affects.

Characteristics, Genetic Testing, and Diagnoses of Infants with Neonatal Encephalopathy Not Due to Hypoxic Ischemic Encephalopathy: A Cohort Study

OBJECTIVE

To characterize the presentation and evaluation of infants with neonatal encephalopathy (NE) not due to hypoxic-ischemic encephalopathy (non-HIE NE) and to describe the genetic abnormalities identified.

STUDY DESIGN

Retrospective cohort study of 193 non-HIE NE neonates admitted to a level IV NICU from 2015 through 2019. For changes in testing over time, Cochrane-Armitage test for trend was used with a Bonferroni-corrected P-value, and comparison between groups was performed using Fisher exact test.

RESULT

The most common symptom of non-HIE NE was abnormal tone in 47% (90/193). Ten percent (19/193) died prior to discharge, and 48% of survivors (83/174) required medical equipment at discharge. Forty percent (77/193) underwent genetic testing as an inpatient. Of 52 chromosomal studies, 54 targeted tests, and 16 exome sequences, 10%, 41%, and 69% were diagnostic, respectively, with no difference in diagnostic rates between infants with and without an associated congenital anomaly and/or dysmorphic feature. Twenty-eight genetic diagnoses were identified.

CONCLUSIONS

Neonates with non-HIE NE have high rates of morbidity and mortality and may benefit from early genetic testing, even in the absence of other exam findings. This study broadens our knowledge of genetic conditions underlying non-HIE NE, which may enable families and care teams to anticipate the needs of the individual, allow early initiation of targeted therapies, and facilitate decisions surrounding goals of care.

Increased newborn NICU admission for evaluation of hypoxic-ischemic encephalopathy during COVID-19 pandemic in a public hospital

Background

Prenatal and perinatal care of pregnant mothers has been adversely affected during the COVID-19 pandemic. Hypoxic-ischemic encephalopathy (HIE) is a leading cause of neonatal death and long-term neurological disabilities. Therapeutic hypothermia is effective for neonatal HIE. This study evaluated the effect of the pandemic on neonatal HIE.

Methods

This retrospective single-center study compared neonatal HIE evaluation and hypothermia treatment between pre-COVID-19 pandemic (1 January 2018-31 December 2019) and COVID-19 pandemic (1 January 2020-31 December 2021) periods. Infants with abnormal neurological examination and or significant metabolic acidosis were admitted to NICU for evaluation of HIE and therapeutic hypothermia. Demographics, NICU admission and interventions, and neonatal outcomes were compared between infants born during the two periods using χ², t-test, and Wilcoxon rank-sum test as appropriate. Statistical Process Control charts show the yearly proportion of infants evaluated for HIE and those treated with therapeutic hypothermia.

Results

From the pre-pandemic to the pandemic period, the proportion of infants that met HIE screening criteria increased from 13% to 16% (p < 0.0001), the proportion of infants admitted to NICU for HIE evaluation increased from 1% to 1.4% (p = 0.02), and the maternal hypertension rates of the admitted infants increased from 30% to 55% (p = 0.006). There was no difference in the proportions of the infants diagnosed with HIE (0.7% vs. 0.9%, p = 0.3) or treated with therapeutic hypothermia (0.2% vs. 0.3%, p = 0.3) between the two periods. There were no differences in the HIE severity and outcomes of the infants treated with therapeutic hypothermia between the two periods.

Conclusion

During the COVID-19 pandemic, we observed a significant increase in NICU admission for HIE evaluation. While we did not find significant increases in neonatal HIE and the need for therapeutic hypothermia, larger studies are needed for a comprehensive assessment of the impact of the COVID-19 pandemic on neonatal HIE.

Selected environmental factors in mothers of newborns subjected to the therapeutic hypothermia - a case control study

OBJECTIVES

Hypothermia is an established method of treating severe forms of perinatal hypoxia in newborns. Some of them develop neonatal encephalopathy, which is associated with high morbidity and mortality. Therefore, prophylaxis of this pathology is important as well as determining environmental factors in mothers of newborns affected by this pathology. The aim of the study was to assess of selected environmental factors in mothers of newborns qualified for hypothermia.

MATERIAL AND METHODS

The material consisted of 102 subjects, including 51 mothers of newborns with hypoxic-ischemic encephalopathy referred for hypothermia treatment (group I) and 51 mothers of newborns without signs of hypoxia (group II). The case-control study was carried out in the third level reference centre. It is 1 of 20 centers of therapeutic hypothermia for newborn in Poland. Data was collected based on a data collection sheet. Study groups were compared in terms of demographic and environmental data. The odds ratio (OR) was determined and the logistic regression analysis of univariate and multivariate regression was used to determine the probability of the need for hypothermia in the study group.

RESULTS

The groups did not differ in terms of age, BMI and place of living. The need to use hypothermia increased in pregnant women living together with their parents (OR = 6.8, 95% CI: 2.4-19.6) also in case of exposure to factors at the workplace, i.e., noise (OR = 4.1, 95% CI: 1.1-15.5).

CONCLUSIONS

Based on the results of our case-control study we postulate to pay attention during preconception care to proper preparation for pregnancy especially in younger women exposed to nuisance in the work environment and at home. In this area postulated activities should include education programs, in close cooperation occupational medicine practitioners and obstetricians even before the conception as a part of pre-conception counseling. Int J Occup Med Environ Health. 2023;36(1):59-68.

Continuous electroencephalography in the intensive care unit: A critical review and position statement from an Australian and New Zealand perspective

Objectives

This article aims to critically review the literature on continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU) from an Australian and New Zealand perspective and provide recommendations for clinicians.

Design and review methods

A taskforce of adult and paediatric neurologists, selected by the Epilepsy Society of Australia, reviewed the literature on cEEG for seizure detection in critically ill neonates, children, and adults in the ICU. The literature on routine EEG and cEEG for other indications was not reviewed. Following an evaluation of the evidence and discussion of controversial issues, consensus was reached, and a document that highlighted important clinical, practical, and economic considerations regarding cEEG in Australia and New Zealand was drafted.

Results

This review represents a summary of the literature and consensus opinion regarding the use of cEEG in the ICU for detection of seizures, highlighting gaps in evidence, practical problems with implementation, funding shortfalls, and areas for future research.

Conclusion

While cEEG detects electrographic seizures in a significant proportion of at-risk neonates, children, and adults in the ICU, conferring poorer neurological outcomes and guiding treatment in many settings, the health economic benefits of treating such seizures remain to be proven. Presently, cEEG in Australian and New Zealand ICUs is a largely unfunded clinical resource that is subsequently reserved for the highest-impact patient groups. Wider adoption of cEEG requires further research into impact on functional and health economic outcomes, education and training of the neurology and ICU teams involved, and securement of the necessary resources and funding to support the service.

Early Biomarkers in the Prediction of Later Functional Impairment in Term Children with Cerebral Palsy

AIM

To identify possible early biomarkers that could predict later functional capabilities in children at risk for cerebral palsy (CP).

METHODS

Data from 869 term children with CP were extracted from the Canadian Cerebral Palsy Registry. Univariate analyses were conducted to measure the association between readily available objective early biomarkers (neonatal encephalopathy [NE], cord or first hour of life pH, magnetic resonance imaging [MRI]) and functional outcomes such as mobility and feeding status. Multivariable regressions were then modeled to study whether adding predictors would affect the strength of the observed association.

RESULTS

Patients with NE have higher odds of having an assigned Gross Motor Function Classification Score level of IV to V (prevalence ratio [PR], 2.87; 95% confidence interval [CI], 2.07 to 3.97) and are more likely to require dependent tube feeding (PR, 2.09; 95% CI, 1.12 to 3.88); this was similarly seen in patients with MRI findings of deep gray matter injury, watershed injury, near-total brain injury, and/or cortical malformation (mobility status [PR, 5.13; 95% CI, 3.73 to 7.11] and feeding status [PR, 4.87; 95% CI, 2.57 to 9.75]). Patients with cord or first hour of life pH <7 were also more likely to predict dependent mobility status (PR, 2.86; 95% CI, 1.76 to 4.69), however, not significantly more likely to predict eventual dependent feeding status (PR, 1.47; 95% CI, 0.58 to 3.32).

CONCLUSIONS

This retrospective cohort study demonstrates that NE, MRI findings and cord or first hour of life pH can reliably predict later CP related functioning. These associations can be used to inform and clarify early prognosis discussions between caregivers and health professionals.

Neutrophil Extracellular Traps Release following Hypoxic-Ischemic Brain Injury in Newborn Rats Treated with Therapeutic Hypothermia

The peripheral immune system plays a critical role in neuroinflammation of the central nervous system after an insult. Hypoxic-ischemic encephalopathy (HIE) induces a strong neuroinflammatory response in neonates, which is often associated with exacerbated outcomes. In adult models of ischemic stroke, neutrophils infiltrate injured brain tissue immediately after an ischemic insult and aggravate inflammation via various mechanisms, including neutrophil extracellular trap (NETs) formation. In this study, we used a neonatal model of experimental hypoxic-ischemic (HI) brain injury and demonstrated that circulating neutrophils were rapidly activated in neonatal blood. We observed an increased infiltration of neutrophils in the brain after exposure to HI. After treatment with either normothermia (NT) or therapeutic hypothermia (TH), we observed a significantly enhanced expression level of the NETosis marker Citrullinated H3 (Cit-H3), which was significantly more pronounced in animals treated with TH than in those treated with NT. NETs and NLR family pyrin domain containing 3 (NLRP-3) inflammasome assembly are closely linked in adult models of ischemic brain injury. In this study, we observed an increase in the activation of the NLRP-3 inflammasome at the time points analyzed, particularly immediately after TH, when we observed a significant increase in NETs structures in the brain. Together, these results suggest the important pathological functions of early arriving neutrophils and NETosis following neonatal HI, particularly after TH treatment, which is a promising starting point for the development of potential new therapeutic targets for neonatal HIE.

Identifying Genetic Susceptibility in Neonates With Hypoxic-Ischemic Encephalopathy: A Retrospective Case Series

Neonatal hypoxic-ischemic encephalopathy is a clinical phenomenon that often results from perinatal asphyxia. To mitigate secondary neurologic injury, prompt initial assessment and diagnosis is needed to identify patients eligible for therapeutic hypothermia. However, occasionally neonates present with a clinical picture of hypoxic-ischemic encephalopathy without significant risk factors for perinatal asphyxia. We hypothesized that in patients with genetic abnormalities, the clinical manifestation of those abnormalities may overlap with hypoxic-ischemic encephalopathy criteria, potentially contributing to a causal misattribution. We reviewed 210 charts of infants meeting local protocol criteria for moderate to severe hypoxic-ischemic encephalopathy in neonatal intensive care units in Calgary, Alberta. All patients that met criteria for therapeutic hypothermia were eligible for the study. Data were collected surrounding pregnancy and birth histories, as well as any available genetic or metabolic testing including microarray, gene panels, whole-exome sequencing, and newborn metabolic screens. Twenty-eight patients had genetic testing such as microarray, whole-exome sequencing, or a gene panel, because of clinical suspicion. Ten of 28 patients had genetic mutations, including CDKL5, pyruvate dehydrogenase, CFTR, CYP21A2, ISY1, KIF1A, KCNQ2, SCN9A, MTFMT, and NPHP1. All patients lacked significant risk factors to support a moderate to severe hypoxic-ischemic encephalopathy diagnosis. Treatment was changed in 2 patients because of confirmed genetic etiology. This study demonstrates the importance of identifying genetic comorbidities as potential contributors to a hypoxic-ischemic encephalopathy phenotype in neonates. Early identification of clinical factors that support an alternate diagnosis should be considered when the patient's clinical picture is not typical of hypoxic-ischemic encephalopathy and could aid in both treatment decisions and outcome prognostication.

The NESHIE and CP Genetics Resource (NCGR): A database of genes and variants reported in neonatal encephalopathy with suspected hypoxic ischemic encephalopathy (NESHIE) and consequential cerebral palsy (CP)

Neonatal encephalopathy (NE) with suspected hypoxic ischaemic encephalopathy (HIE) (NESHIE) is a complex syndrome occurring in newborns, characterised by altered neurological function. It has been suggested that genetic variants may influence NESHIE susceptibility and outcomes. Unlike NESHIE, for which a limited number of genetic studies have been performed, many studies have identified genetic variants associated with cerebral palsy (CP), which can develop from severe NESHIE. Identifying variants in patients with CP, as a consequence of NESHIE, may provide a starting point for the identification of genetic variants associated with NESHIE outcomes. We have constructed NCGR (NESHIE and CP Genetics Resource), a database of genes and variants reported in patients with NESHIE and CP (where relevant to NESHIE), for the purpose of collating and comparing genetic findings between the two conditions. In this paper we describe the construction and functionality of NCGR. Furthermore, we demonstrate how NCGR can be used to prioritise genes and variants of potential clinical relevance that may underlie a genetic predisposition to NESHIE and contribute to an understanding of its pathogenesis.

Neuroprotective therapies in the NICU in term infants: present and future

Outcomes of neonatal encephalopathy (NE) have improved since the widespread implementation of therapeutic hypothermia (TH) in high-resource settings. While TH for NE in term and near-term infants has proven beneficial, 30-50% of infants with moderate-to-severe NE treated with TH still suffer death or significant impairments. There is therefore a critical need to find additional pharmacological and non-pharmacological interventions that improve the outcomes for these children. There are many potential candidates; however, it is unclear whether these interventions have additional benefits when used with TH. Although primary and delayed (secondary) brain injury starting in the latent phase after HI are major contributors to neurodisability, the very late evolving effects of tertiary brain injury likely require different interventions targeting neurorestoration. Clinical trials of seizure management and neuroprotection bundles are needed, in addition to current trials combining erythropoietin, stem cells, and melatonin with TH. IMPACT: The widespread use of therapeutic hypothermia (TH) in the treatment of neonatal encephalopathy (NE) has reduced the associated morbidity and mortality. However, 30-50% of infants with moderate-to-severe NE treated with TH still suffer death or significant impairments. This review details the pathophysiology of NE along with the evidence for the use of TH and other beneficial neuroprotective strategies used in term infants. We also discuss treatment strategies undergoing evaluation at present as potential adjuvant treatments to TH in NE.

Study on NGF and VEGF during the Equine Perinatal Period-Part 2: Foals Affected by Neonatal Encephalopathy

Neonatal Encephalopathy (NE) may be caused by hypoxic ischemic insults or inflammatory insults and modified by innate protective or excitatory mechanisms. Understanding the underlying pathophysiology is important in formulating a rational approach to diagnosis. The preliminary aim was to clinically characterize a population of foals spontaneously affected by NE. The study aimed to: (i) evaluate nerve growth factor (NGF) and vascular endothelial growth factor (VEGF) levels in plasma samples obtained in the affected population at parturition from the mare’s jugular vein, umbilical cord vein and foal’s jugular vein, as well as in amniotic fluid; (ii) evaluate the NGF and VEGF content in the plasma of foals affected by NE during the first 72 h of life/hospitalization; (iii) evaluate NGF and VEGF levels at birth/admission in relation to selected mare’s and foal’s clinical parameters; (iv) evaluate the relationship between the two trophic factors and thyroid hormone levels (TT3 and TT4) in the first 72 h of life/hospitalization; and (v) assess the mRNA expression of NGF, VEGF and brain-derived neurotrophic factor (BDNF), and their cell surface receptors, in the placenta of mares that delivered foals affected by NE. Thirteen affected foals born from mares hospitalized for peripartum monitoring (group NE) and twenty affected foals hospitalized after birth (group exNE) were included in the study. Dosage of NGF and VEGF levels was performed using commercial ELISA kits, whereas NGF, VEGF, and BDNF placental gene expression was performed using a semi-quantitative real-time PCR. In group NE, NGF levels decreased significantly from T0 to T24 (p = 0.0447) and VEGF levels decreased significantly from T0 to T72 (p = 0.0234), whereas in group exNE, only NGF levels decreased significantly from T0 to T24 (p = 0.0304). Compared to healthy foals, a significant reduction of TT3 levels was observed in both NE (T24, p = 0.0066; T72 p = 0.0003) and exNE (T0, p = 0.0082; T24, p < 0.0001; T72, p < 0.0001) groups, whereas a significant reduction of TT4 levels was observed only in exNE group (T0, p = 0.0003; T24, p = 0.0010; T72, p = 0.0110). In group NE, NGF levels were positively correlated with both TT3 (p = 0.0475; r = 0.3424) and TT4 levels (p = 0.0063; r = 0.4589). In the placenta, a reduced expression of NGF in the allantois (p = 0.0033) and a reduced expression of BDNF in the amnion (p = 0.0498) were observed. The less pronounced decrease of the two trophic factors compared to healthy foals, their relationship with thyroid hormones over time, and the reduced expression of NGF and BDNF in placental tissues of mares that delivered affected foals, could be key regulators in the mechanisms of equine NE.

Azithromycin reduces inflammation-amplified hypoxic-ischemic brain injury in neonatal rats

BACKGROUND

Systemic inflammation amplifies neonatal hypoxic-ischemic (HI) brain injury. Azithromycin (AZ), an antibiotic with anti-inflammatory properties, improves sensorimotor function and reduces tissue damage after neonatal rat HI brain injury. The objective of this study was to determine if AZ is neuroprotective in two neonatal rat models of inflammation-amplified HI brain injury.

DESIGN/METHODS

Seven-day-old (P7) rats received injections of toll-like receptor agonists lipopolysaccharide (LPS) or Pam₃Cys-Ser-(Lys)₄ (PAM) prior to right carotid ligation followed by 50 min (LPS + HI) or 60 min (PAM + HI) in 8% oxygen. Outcomes included contralateral forelimb function (forepaw placing; grip strength), survival, %Intact right hemisphere (brain damage), and a composite score incorporating these measures. We compared postnatal day 35 outcomes in controls and groups treated with three or five AZ doses. Then, we compared P21 outcomes when the first (of five) AZ doses were administered 1, 2, or 4 h after HI.

RESULTS

In both LPS + HI and PAM + HI models, AZ improved sensorimotor function, survival, brain tissue preservation, and composite scores. Benefits increased with five- vs. three-dose AZ and declined with longer initiation delay.

CONCLUSIONS

Perinatal systemic infection is a common comorbidity of neonatal asphyxia brain injury and contributes to adverse outcomes. These data support further evaluation of AZ as a candidate treatment for neonatal neuroprotection.

IMPACT

AZ treatment decreases sensorimotor impairment and severity of brain injury, and improves survival, after inflammation-amplified HI brain injury, and this can be achieved even with a 2 h delay in initiation. This neuroprotective benefit is seen in models of inflammation priming by both Gram-negative and Gram-positive infections. This extends our previous findings that AZ treatment is neuroprotective after HI brain injury in neonatal rats.

Uterine activity in labour and the risk of neonatal encephalopathy: a case control study

OBJECTIVE

To determine the relationship between intrapartum contraction frequency, rest interval duration, and cervical dilation speed and the risk of neonatal hypoxic-ischemic encephalopathy (HIE).

STUDY DESIGN

This was a retrospective case-control study conducted in a maternity hospital in Dublin, Ireland. Babies born without major congenital anomalies between September 2006 and November 2017 at ≥ 35 + 0 weeks' gestational age were eligible. Cases were diagnosed with moderate-severe HIE. The controls were the first eligible baby born before and after each case with normal Apgar scores and not admitted to the neonatal unit. Intrapartum uterine activity was assessed by automated analysis of external tocography recordings. Cervical dilation was assessed by linear interpolation between vaginal examination measurements. The speed of cervical dilation was expressed as the times from 4 to 6 cm, >6 cm to the start of pushing, and from pushing to delivery.

RESULTS

Intrapartum tocographs results were available in 49 of 88 cases and 121 of 176 controls. The median contraction rate in cases was 7.7 (Interquartile range [IQR]: 6.6-9.0) compared to 7.0 in controls (IQR: 6.2-7.9) (p = 0.021). The median rest interval duration was 56 s (IQR: 38-76) in cases and 62 s (IQR: 50-79) in controls (p = 0.058). Cases took longer to progress from > 6 cm to the start of pushing (cases: 02:58 [01:14-04:49], controls: 01:48 [00:51-03:34], p = 0.020) and from pushing to delivery (cases: 00:34 [00:24-01:10], controls: 00:27 [00:13-00:56], p = 0.036).

CONCLUSIONS

Higher contraction frequencies and slower progress towards the end of labour are both independently associated with the risk of moderate-severe HIE. Inter-contraction rest interval duration as measured by external tocography does not provide additional accuracy.

Core outcomes in neonatal encephalopathy: a qualitative study with parents

OBJECTIVE

To identify the outcomes considered important to parents or caregivers of infants diagnosed with neonatal encephalopathy, hypoxic ischaemic encephalopathy or birth asphyxia in high-income and low- to middle-income countries (LMiCs), as part of the outcome-identification process in developing a core outcome set (COS) for the treatment of neonatal encephalopathy.

DESIGN

A qualitative study involving 25 semistructured interviews with parents or other family members (caregivers) of infants who were diagnosed with, and treated for, neonatal encephalopathy, hypoxic ischaemic encephalopathy or birth asphyxia.

SETTING

Interviews were conducted in high-income countries (HiCs) (n=11) by Zoom video conferencing software and in LMiCs (n=14) by phone or face to face.

FINDINGS

Parents identified 54 outcomes overall, which mapped to 16 outcome domains. The domains identified were neurological outcomes, respiratory outcomes, gastrointestinal outcomes, cardiovascular outcomes, motor development, cognitive development, development (psychosocial), development (special senses), cognitive development, development (speech and social), other organ outcomes, survival/living outcomes, long-term disability, hospitalisation, parent-reported outcomes and adverse events.

CONCLUSIONS

This study provides insight into the outcomes that parents of infants diagnosed with neonatal encephalopathy have identified as the most important, to be considered in the process of developing a COS for the treatment of neonatal encephalopathy. We also provide description of the processes employed to ensure the inclusion of participants from LMiCs as well as HiCs.

Background suppression of electrical activity is a potential biomarker of subsequent brain injury in a rat model of neonatal hypoxia-ischemia

Electrographic seizures and abnormal background activity in the neonatal electroencephalogram (EEG) may differentiate between harmful versus benign brain insults. Using two animal models of neonatal seizures, electrical activity was recorded in freely behaving rats and examined quantitatively during successive time periods with field-potential recordings obtained shortly after the brain insult (i.e., 0-4 days). Single-channel, differential recordings with miniature wireless telemetry were used to analyze spontaneous electrographic seizures and background suppression of electrical activity after 1) hypoxia-ischemia (HI), which is a model of neonatal encephalopathy that causes acute seizures and a large brain lesion with possible development of epilepsy, 2) hypoxia alone (Ha), which causes severe acute seizures without an obvious lesion or subsequent epilepsy, and 3) sham control rats. Background EEG exhibited increases in power as a function of age in control animals. Although background electrical activity was depressed in all frequency bands immediately after HI, suppression in the β and γ bands was greatest and lasted longest. Spontaneous electrographic seizures were recorded, but only in a few HI-treated animals. Ha-treated rat pups were similar to sham controls, they had no subsequent spontaneous electrographic seizures after the treatment and background suppression was only briefly observed in one frequency band. Thus, the normal age-dependent maturation of electrical activity patterns in control animals was significantly disrupted after HI. Suppression of the background EEG observed here after HI-induced acute seizures and subsequent brain injury may be a noninvasive biomarker for detecting severe brain injuries and may help predict subsequent epilepsy.NEW & NOTEWORTHY Biomarkers of neonatal brain injury are needed. Hypoxia-ischemia (HI) in immature rat pups caused severe brain injury, which was associated with strongly suppressed background EEG. The suppression was most robust in the β and γ bands; it started immediately after the HI injury and persisted for days. Thus, background suppression may be a noninvasive biomarker for detecting severe brain injuries and may help predict subsequent epilepsy.

Electrographic Seizures in Neonates with a High Risk of Encephalopathy

Background: Neonatal encephalopathy is caused by a wide variety of acute brain insults in newborns and presents with a spectrum of neurologic dysfunction, such as consciousness disturbance, seizures, and coma. The increased excitability in the neonatal brain appears to be highly susceptible to seizures after a variety of insults, and seizures may be the first clinical sign of a serious neurologic disorder. Subtle seizures are common in the neonatal period, and abnormal clinical paroxysmal events may raise the suspicion of neonatal seizures. Continuous video electroencephalographic (EEG) monitoring is the gold standard for the diagnosis of neonatal seizures. The aim of this study was to identify the prevalence of electrographic seizures and the impact of monitoring in neonates with a high risk of encephalopathy. Methods: We conducted this prospective cohort study in a tertiary neonatal intensive care unit over a 4-year period. Neonates with a high risk of encephalopathy who were receiving continuous video EEG monitoring were eligible. The patients were divided into 2 groups: (1) acute neonatal encephalopathy (ANE) and (2) other high-risk encephalopathy conditions (OHRs). The neonates’ demographic characteristics, etiologies, EEG background feature, presence of electrographic seizures and the impact of monitoring were analyzed. Results: A total of 71 neonates with a high risk of encephalopathy who received continuous video EEG monitoring were enrolled. In this consecutive cohort, 42 (59.2%) were monitored for ANE and 29 (40.8%) were monitored for OHRs. At the time of starting EEG monitoring, 54 (76.1%) of the neonates were term infants. The median gestational age at monitoring was 39 weeks (interquartile range, 37−41 weeks). The median total EEG monitoring duration was 64.7 h (interquartile range, 22.2−72.4 h). Electrographic seizures were captured in 25 of the 71 (35.2%) neonates, of whom 20 (80%) had electrographic-only seizures without clinical correlation. Furthermore, of these 20 neonates, 13 (65%) developed electrographic status epilepticus. Electrographic seizures were most commonly found in the ANE group (17, 40.5%) than in the OHRs group (8, 27.6%) (p = 0.013). Besides, normal/mild abnormality and inactive EEG background were less electrographic seizure than moderate and major abnormality EEG background (2 of 30, 6.7% vs. 23 of 41, 56.1%, p < 0.001). Finally, continuous video EEG monitoring excluded the diagnosis of electrographic seizures in two-thirds of the monitored neonates who had paroxysmal events mimicking seizures and led to a change in clinical management in 39.4% of the neonates. Conclusions: Our findings showed that monitoring could accurately detect seizures, and that it could be used to guide seizure medication management. Therefore, continuous video EEG monitoring has important clinical management implications in neonates with a high risk of encephalopathy.

Temporal Characterization of Microglia-Associated Pro- and Anti-Inflammatory Genes in a Neonatal Inflammation-Sensitized Hypoxic-Ischemic Brain Injury Model

Hypoxic-ischemic encephalopathy (HIE) mainly affects preterm and term newborns, leading to a high risk of brain damage. Coexisting infection/inflammation and birth asphyxia are key factors associated with intracerebral increase of proinflammatory cytokines linked to HIE. Microglia are key mediators of inflammation during perinatal brain injury, characterized by their phenotypic plasticity, which may facilitate their participation in both the progression and resolution of injury-induced inflammation. The purpose of this study was to investigate the temporal expression of genes associated with pro- and anti-inflammatory cytokines as well as the nucleotide-binding domain, leucine-rich repeat protein (NLRP-3) inflammasome from microglia cells. For this purpose, we used our established neonatal rat model of inflammation-sensitized hypoxic-ischemic (HI) brain injury in seven-day-old rats. We assessed gene expression profiles of 11 cytokines and for NLRP-3 using real-time PCR from sorted CD11b/c microglia of brain samples at different time points (3.5 h after LPS injection and 0, 5, 24, 48, and 72 hours post HI) following different treatments: vehicle, E. coli lipopolysaccharide (LPS), vehicle/HI, and LPS/HI. Our results showed that microglia are early key mediators of the inflammatory response and exacerbate the inflammatory response following HI, polarizing into a predominant proinflammatory M1 phenotype in the early hours post HI. The brains only exposed to HI showed a delay in the expression of proinflammatory cytokines. We also demonstrated that NLRP-3 plays a role in the inflammatory resolution with a high expression after HI insult. The combination of both, a preinfection/inflammation condition and hypoxia-ischemia, resulted in a higher proinflammatory cytokine storm, highlighting the significant contribution of acute inflammation sensitizing prior to a hypoxic insult on the severity of perinatal brain damage.

Risk factors for neonatal encephalopathy in late preterm and term singleton births in a large California birth cohort

OBJECTIVE

The objective was to investigate maternal and pregnancy characteristics associated with neonatal encephalopathy (NE).

STUDY DESIGN

We queried an administrative birth cohort from California between 2011 and 2017 to determine the association between each factor and NE with and without hypothermia treatment.

RESULTS

From 3 million infants born at 35 or more weeks of gestation, 6,857 cases of NE were identified (2.3 per 1000 births), 888 (13%) received therapeutic hypothermia. Risk factors for NE were stronger among cases receiving hypothermia therapy. Substance-related diagnosis, preexisting diabetes, preeclampsia, and any maternal infection were associated with a two-fold increase in risk. Maternal overweight/obesity, nulliparity, advanced maternal age, depression, gestational diabetes or hypertension, and short or long gestations also predicted NE. Young maternal age, Asian race and Hispanic ethnicity, and cannabis-related diagnosis lowered risk of NE.

CONCLUSIONS

By disseminating these results, we encourage further interrogation of these perinatal factors.

Multi-organ dysfunction scoring in neonatal encephalopathy (MODE Score) and neurodevelopmental outcomes

AIM

Neonatal encephalopathy (NE) is associated with an increased risk of multi-organ injury. The lack of standardised definitions for multi-organ dysfunction in NE hinders accurate quantification of these complications.

METHODS

A simple multi-organ dysfunction in neonatal encephalopathy scoring (MODE) system was created to include the cardiovascular, respiratory, gastrointestinal, haematological and neurological systems with a maximum score of 15. The MODE score was then compared with the grade of NE, Bayley Scales of Infant Development (Bayley-III) at 2 years of age and mortality. The Bayley score was used as it gave an objective score making it easier to compare the MODE score. Bayley score of <90 and/or abnormal MRI as an adverse outcome.

RESULTS

Infants with perinatal asphyxia (PA:n = 85) were prospectively enrolled (PA only n = 9; NE I = 23; NE II = 42; NE III = 11). Infants with higher MODE scores were significantly more likely to have moderate/severe NE (NE II/III: median scores (IQR) 7(5-10) versus mild NE 2 (1-3); p-value < 0.001) The MODE score was highly predictive of mortality (AUC 0.96, p-value = 0.002). Infants who had an abnormal neurological examination at discharge or abnormal Bayley-III scores had significantly higher MODE scores (p-value = 0.001).

CONCLUSION

Quantifying multi-organ injury is important to plan optimal early management and long-term follow-up. Additional use of clinical biomarkers may be useful as surrogate endpoints in future clinical trials and link to multi-organ longer-term developmental follow-up.

Therapeutic hypothermia for encephalopathic newborns with congenital heart defect: A cross-sectional survey on current practices and opinions in Germany

BACKGROUND

Therapeutic hypothermia (TH) reduces neonatal mortality and long-term neurodevelopmental impairment in infants with moderate-to-severe hypoxic-ischemic encephalopathy (HIE) caused by perinatal asphyxia. There is an increasing trend to apply TH in other indications and populations, such as infants with mild HIE or neonates with congenital heart defects (CHD), even though there is little evidence to support or refute this.

OBJECTIVE

The aim of this survey was to analyze practice variations with respect to TH use in neonates with CHD and to assess expert opinions on this topic across tertiary neonatal departments in Germany.

METHODS/DESIGN

A web-based survey was sent to all tertiary neonatal departments in Germany. The questionnaire contained 32 multiple-choice questions. The survey inquired current practices on TH in newborns with CHD and expert opinions on various clinical scenarios.

MAIN RESULTS

A total 80 (51.3%) neonatal departments partially completed the survey, and 69 (44.2%) respondents filled out the whole questionnaire. All 80 (100.0%) departments perform TH. TH is offered by 76 (95.0%) respondents to encephalopathic newborns with simple CHD. In infants with critical/complex CHD, TH is offered after perinatal asphyxial HIE and in newborns with encephalopathy after severe acidosis associated with cardiac complications by 25 (31.3%), or 17 (22.1%) respondents, respectively, whereas a clear majority of centers reject TH in these infants. Unclear effects of TH on any ongoing prostaglandin therapy (57.6 and 52.3%, respectively), an increased risk for adverse reactions during TH (51.6 and 52.3%, respectively) and lack of evidence (33.3 and 53.8%, respectively) are the most frequently cited reasons for not performing TH in these infants. The majority of experts from neonatal departments providing comprehensive care for neonates with severe CHD support the initiation of TH in encephalopathic neonates.

DISCUSSION

The considerable heterogeneity in the use of TH in neonates with CHD emphasizes the need for further research to optimize treatment strategies for these patients.

Cause of Death in Neonates With Neurological Insults in the Neonatal Intensive Care Unit: Insights From A MITS Pilot Study

Background

Minimally invasive tissue sampling (MITS) of organs has been used as an alternative to complete diagnostic autopsy in countries where refusal for autopsy in newborns is common for sociocultural reasons. There is a paucity of literature regarding the diagnostic utility of MITS of the brain after death in neonates with neurological insults, especially in India.

Methods

This was a prospective, preliminary single-center tertiary care hospital study in India, focused specifically on MITS of the brain after neonatal death as a diagnostic tool to identify the various neurological insults. All neonatal deaths with neurological symptoms occurring within the first 30 days of life were enrolled, irrespective of the suspected clinical diagnosis.

Results

Sixteen neonates were enrolled after death for MITS of the brain, performed for diagnostic purposes, during the study period from February 2020 to March 2021. Their gestational ages ranged from 26 to 38 weeks. All neonates had either a history of seizures and/or respiratory distress or clinical evidence of sepsis and were on ventilator support. Histopathology in all 16 neonates showed evidence of anoxia, with or without reactive astrogliosis or microgliosis. In 5 neonates with cranial ultrasound evidence of brain hemorrhage, MITS of the brain showed intraventricular hemorrhage, subdural hemorrhage, or intraparenchymal white matter microhemorrhages. Premortem blood culture–proven sepsis was seen in 9 neonates. In all cases (100%), MITS had a good diagnostic yield and was useful to establish the neurological insult in the brain.

Conclusions

MITS of the brain provides an accurate and adequate diagnosis and can be an alternative to complete diagnostic autopsy for establishing the cause of death due to neurological insults, especially in low-resource settings where obtaining consent for more invasive procedure is often challenging.

The role of lymphocytes in neonatal encephalopathy

Neonatal encephalopathy is a syndrome characterised by abnormal neurological function often caused by a hypoxic insult during childbirth. Triggers such as hypoxia-ischaemia result in the release of cytokines and chemokines inducing the infiltration of neutrophils, natural killer cells, B cells, T cells and innate T cells into the brain. However, the role of these cells in the development of the brain injury is poorly understood. We review the mechanisms by which lymphocytes contribute to brain damage in NE. NK, T and innate T cells release proinflammatory cytokines contributing to the neurodegeneration in the secondary and tertiary phase of injury, whereas B cells and regulatory T cells produce IL-10 protecting the brain in NE. Targeting lymphocytes may have therapeutic potential in the treatment of NE in terms of management of inflammation and brain damage, particularly in the tertiary or persistent phases.

Medico-legal considerations in the context of neonatal encephalopathy and therapeutic hypothermia

Neonatal encephalopathy (NE) is a significant complication of the peripartum period. It can lead to lifelong neurologic disabilities, including cerebral palsy, cognitive impairments, developmental delays, and epilepsy. Induced hypothermia is the first therapy, which has shown promise in improving the outcomes for neonates with moderate to severe NE following a presumed intrapartum insult. NE is also a frequent source of medical malpractice litigation. In this paper, we will review salient features of the American Tort System as it pertains to medical malpractice. We will discuss the obstetric medico-legal implications of therapeutic hypothermia and suggest a five-step approach to analyzing neonatal cases for causation, etiology, timing of occurrence, responsibility, and liability. We will close with three illustrative clinical cases.

Unanswered questions regarding therapeutic hypothermia for neonates with neonatal encephalopathy

Therapeutic hypothermia (TH) is now well established to improve intact survival after neonatal encephalopathy (NE). However, many questions could not be addressed by the randomized controlled trials. Should late preterm newborns with NE be cooled? Is cooling beneficial for mild NE? Is the current therapeutic time window optimal, or could it be shortened or prolonged? Will either milder or deeper hypothermia be effective? Does infection/inflammation exposure in the perinatal period in combination with NE offer potentially beneficial preconditioning or might it obviate hypothermic neuroprotection? In the present review, we dissect the evidence, for whom, when and how can TH best be delivered, and highlight areas that need further research.

Neonatal encephalopathy: Etiologies other than hypoxic-ischemic encephalopathy

Neonatal encephalopathy (NE) describes the clinical syndrome of a newborn with abnormal brain function that may result from a variety of etiologies. HIE should be distinguished from neonatal encephalopathy due to other causes using data gathered from the history, physical and neurological exam, and further investigations. Identifying the underlying cause of encephalopathy has important treatment implications. This review outlines conditions that cause NE and may be mistaken for HIE, along with their distinguishing clinical features, pathophysiology, investigations, and treatments. NE due to brain malformations, vascular causes, neuromuscular causes, genetic conditions, neurogenetic disorders and inborn errors of metabolism, central nervous system (CNS) and systemic infections, and toxic/metabolic disturbances are discussed.

Novel Point-of-Care Diagnostic Method for Neonatal Encephalopathy Using Purine Nucleosides

Background: Evidence suggests that earlier diagnosis and initiation of treatment immediately after birth is critical for improved neurodevelopmental outcomes following neonatal encephalopathy (NE). Current diagnostic tests are, however, mainly restricted to clinical diagnosis with no molecular tests available. Purines including adenosine are released during brain injury such as hypoxia and are also present in biofluids. Whether blood purine changes can be used to diagnose NE has not been investigated to date.

Methods: Blood purines were measured in a mouse model of neonatal hypoxia and infants with NE using a novel point-of-care diagnostic technology (SMARTChip) based on the summated electrochemical detection of adenosine and adenosine metabolites in the blood.

Results: Blood purine concentrations were ∼2–3-fold elevated following hypoxia in mice [2.77 ± 0.48 μM (Control) vs. 7.57 ± 1.41 μM (post-hypoxia), p = 0.029]. Data in infants with NE had a 2–3-fold elevation when compared to healthy controls [1.63 ± 0.47 μM (Control, N = 5) vs. 4.87 ± 0.92 μM (NE, N = 21), p = 0.0155]. ROC curve analysis demonstrates a high sensitivity (81%) and specificity (80%) for our approach to identify infants with NE. Moreover, blood purine concentrations were higher in infants with NE and seizures [8.13 ± 3.23 μM (with seizures, N = 5) vs. 3.86 ± 0.56 μM (without seizures, N = 16), p = 0.044].

Conclusion: Our data provides the proof-of-concept that measurement of blood purine concentrations via SMARTChip technology may offer a low-volume bedside test to support a rapid diagnosis of NE.

Fluid management, electrolytes imbalance and renal management in neonates with neonatal encephalopathy treated with hypothermia

Kidney dysfunction and acute kidney injury (AKI) frequently accompanies neonatal encephalopathy and contributes to neonatal morbidity and mortality. While there are currently no proven therapies for the treatment of AKI, understanding the pathophysiology along with early recognition and treatment of alterations in fluid, electrolyte and metabolic homeostasis that accompany AKI offer opportunity to reduce associated morbidity. Promising new tests and technologies, including urine and serum biomarkers and renal near-infrared spectroscopy offer opportunities to improve diagnosis and monitoring of neonates at risk for kidney injury. Furthermore, recent advances in neonatal kidney supportive therapies such as hemofiltration and hemodialysis may further improve outcomes in this population. This chapter provides an overview of disorders of fluid balance, electrolyte homeostasis and kidney function associated with neonatal encephalopathy and therapeutic hypothermia. Recommendations for fluid and electrolyte management based upon published literature and authors' opinions are provided.

Neonatal encephalopathy: Focus on epidemiology and underexplored aspects of etiology

Neonatal Encephalopathy (NE) is a neurologic syndrome in term and near-term infants who have depressed consciousness, difficulty initiating and maintaining respiration, and often abnormal tone, reflexes and neonatal seizures in varying combinations. Moderate/severe NE affects 0.5-3/1000 live births in high-income countries, more in low- and middle-income countries, and carries high risk of mortality or disability, including cerebral palsy. Reduced blood flow and/or oxygenation around the time of birth, as with ruptured uterus, placental abruption or umbilical cord prolapse can cause NE. This subset of NE, with accompanying low Apgar scores and acidemia, is termed Hypoxic-Ischemic Encephalopathy. Other causes of NE that can present similarly, include infections, inflammation, toxins, metabolic disease, stroke, placental disease, and genetic disorders. Aberrant fetal growth and congenital anomalies are strongly associated with NE, suggesting a major role for maldevelopment. As new tools for differential diagnosis emerge, their application for prevention, individualized treatment and prognostication will require further systematic studies of etiology of NE.

The Term Newborn: Evaluation for Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy due to perinatal hypoxia-ischemia (hypoxic-ischemic encephalopathy [HIE]) occurs at a rate of 1 to 3 per 1000 live births. Therapeutic hypothermia is the standard of care and the only currently available therapy to reduce the risk of death or disability in newborns with moderate to severe HIE. Hypothermia therapy needs to be initiated within 6 hours after birth in order to provide the best chance for neuroprotection. All pediatricians and delivery room attendants should be trained to recognize encephalopathy and understand the eligibility criteria for treatment. The modified Sarnat examination is the most frequently used tool to assess the degree of encephalopathy and has six categories, each of which can have mild, moderate, severe abnormalities. Apart from historical and biochemical criteria, a neonate must have 3 of 6 categories scored in the moderate or severe range in order to qualify for hypothermia as was done in the randomized trials. Whether an infant qualifies or there is concern that an infant might have HIE, transfer to a center that can perform treatment should be initiated immediately. Hypothermia significantly reduces the risk of death or moderate to severe impairments at 2 years and at school age. On average, only 7 neonates need to be treated for one neonate to benefit. Although easy in concept, implementation of hypothermia does require expertise and should be carried out under the guidance of a neonatologist. If infants are passively cooled prior to transport, core temperature needs to be closely monitored with a target of 33.5°C ± 0.5°C. Maintenance of homeostasis is important in order to prevent conditions that may result in additional brain injury. Seizures are common in neonates with HIE, but electrographic seizures are rare in the first few hours after birth if the insult occurred during labor and delivery. Prophylactic antiepileptic drugs should not be administered. Brain monitoring in the form of electroencephalogram (EEG) and or amplitude-integrated EEG should be implemented as soon as possible to help with prognosis and to accurately diagnose seizures.