Clinical Neonatal Seizures are Independently Associated with Outcome in Infants at Risk for Hypoxic-Ischemic Brain Injury

Neonatal Seizures

Neonatal seizures are common among patients with acute brain injury or critical illness and can be difficult to diagnose and treat. The most common etiology of neonatal seizures is hypoxic-ischemic encephalopathy, with other common causes including ischemic stroke and intracranial hemorrhage. Neonatal clinicians can use a standardized approach to patients with suspected or confirmed neonatal seizures that entails laboratory testing, neuromonitoring, and brain imaging. The primary goals of management of neonatal seizures are to identify the underlying cause, correct it if possible, and prevent further brain injury. This article reviews recent evidence-based guidelines for the treatment of neonatal seizures and discusses the long-term outcomes of patients with neonatal seizures.

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.

Electrographic monitoring for seizure detection in the neonatal unit: current status and future direction

Neonatal neurocritical intensive care is dedicated to safeguarding the newborn brain by prioritising clinical practices that promote early identification, diagnosis and treatment of brain injuries. The most common newborn neurological emergency is neonatal seizures, which may also be the initial clinical indication of neurological disease. A high seizure burden in the newborn period independently contributes to increased mortality and morbidity. The majority of seizures in newborns are subclinical (without clinical presentation), and hence identification may be difficult. Neuromonitoring techniques most frequently used to monitor brain wave activity include conventional electroencephalography (cEEG) or amplitude-integrated EEG (aEEG). cEEG with video is the gold standard for diagnosing and treating seizures. Many neonatal units do not have access to cEEG, and frequently those that do, have little access to real-time interpretation of monitoring. IMPACT: EEG monitoring is of no benefit to an infant without expert interpretation. Whilst EEG is a reliable cot-side tool and of diagnostic and prognostic use, both conventional EEG and amplitude-integrated EEG have strengths and limitations, including sensitivity to seizure activity and ease of interpretation. Automated seizure detection requires a sensitive and specific algorithm that can interpret EEG in real-time and identify seizures, including their intensity and duration.

Association Between Seizures and Neurodevelopmental Outcome at Two and Five Years in Asphyxiated Newborns With Therapeutic Hypothermia

OBJECTIVE

To investigate the association between the presence and severity of seizures in asphyxiated newborns and their neurodevelopmental outcome at ages two and five years.

METHODS

Retrospective data analysis from a prospectively collected multicenter cohort of 186 term-born asphyxiated newborns undergoing therapeutic hypothermia (TH) in 11 centers in the Netherlands and Belgium. Seizures were diagnosed by amplitude-integrated electroencephalography (EEG) and raw EEG signal reading up to 48 hours after rewarming. Neurodevelopmental outcome was assessed by standardized testing at age two and five years. Primary outcome was death or long-term neurodevelopmental impairment (NDI) including cerebral palsy. Associations were calculated using univariate and multivariate logistic regression analyses adjusting for Thompson score and a validated brain magnetic resonance imaging (MRI) score.

RESULTS

Seventy infants (38%) had seizures during TH or rewarming, and 44 (63%) of these needed two or more antiseizure medications (ASMs). Overall mortality was 21%. Follow-up data from 147 survivors were available for 137 infants (93%) at two and for 94 of 116 infants (81%) at five years. NDI was present in 26% at two and five years. Univariate analyses showed a significant association between seizures and death or NDI, but this was no longer significant after adjusting for Thompson and MRI score in the multivariate analysis; this was also true for severe seizures (need for two or more ASMs) or seizures starting during rewarming.

CONCLUSION

The presence or severity of seizures in newborns undergoing TH for hypoxic-ischemic encephalopathy was not independently associated with death or NDI up to age five years after adjusting for several confounders.

Epilepsy Incidence and Developmental Outcomes After Early Discontinuation of Antiseizure Medication in Neonatal Hypoxic-Ischemic Encephalopathy

BACKGROUND

Neonatal seizures caused by hypoxic-ischemic encephalopathy (HIE) have significant morbidity and mortality. There is variability in clinical practice regarding treatment duration with antiseizure medication (ASM) after resolution of provoked neonatal seizures. We examined epilepsy incidence and developmental outcomes in post-HIE neonates discharged or not on ASM.

METHODS

We conducted a retrospective chart review of all HIE-admitted neonates to the University of Iowa Hospitals & Clinics neonatal intensive care unit between January 2008 and February 2021 who presented with encephalopathy, underwent therapeutic hypothermia, and developed seizures. Neonates were divided into two groups depending on whether ASM was continued or discontinued on discharge. We evaluated the incidence of epilepsy and developmental outcomes on follow-up in these two cohorts up to 12 months.

RESULTS

Sixty-nine neonates met the study criteria. ASM was continued on discharge in 41 neonates (59%) and discontinued before discharge in 28 (41%). At the 12-month follow-up, nine neonates (13%) had a diagnosis of epilepsy, out of which seven neonates had ASM continued on discharge (odds ratio [OR]: 2.84; 95% confidence interval [CI]: 0.48, 29.9)]. There was no statistical difference between the development of postneonatal epilepsy between the two groups (P value 0.29). There was no significant difference in developmental outcome between the two groups after adjusting for covariates like magnetic resonance imaging (MRI) brain abnormality and number of seizure days (OR: 0.68; 95% CI: 0.21, 2.22; P = 0.52).

CONCLUSION

We found no significant risk of seizure recurrence by age 12 months in infants who had discontinued ASM before discharge compared with those who had continued ASM. There was no difference in developmental outcomes at the 12-month follow-up between groups after adjusting for brain MRI abnormality and the number of seizure days during admission. Our results support early discontinuation of ASM after resolution of acute provoked seizures in neonates with HIE.

Anti-seizure medication-induced developmental cell death in neonatal rats is unaltered by history of hypoxia

BACKGROUND

Many anti-seizure medications (ASMs) trigger neuronal cell death when administered during a confined period of early life in rodents. Prototypical ASMs used to treat early-life seizures such as phenobarbital induce this effect, whereas levetiracetam does not. However, most prior studies have examined the effect of ASMs in naïve animals, and the degree to which underlying brain injury interacts with these drugs to modify cell death is poorly studied. Moreover, the degree to which drug-induced neuronal cell death differs as a function of sex is unknown.

METHODS

We treated postnatal day 7 Sprague Dawley rat pups with vehicle, phenobarbital (75 mg/kg) or levetiracetam (200 mg/kg). Separate groups of pups were pre-exposed to either normoxia or graded global hypoxia. Separate groups of males and females were used. Twenty-four hours after drug treatment, brains were collected and processed for markers of cell death.

RESULTS

Consistent with prior studies, phenobarbital, but not levetiracetam, increased cell death in cortical regions, basal ganglia, hippocampus, septum, and lateral thalamus. Hypoxia did not modify basal levels of cell death. Females - collapsed across treatment and hypoxia status, displayed a small but significant increase in cell death as compared to males in the cingulate cortex, somatosensory cortex, and the CA1 and CA3 hippocampus; these effects were not modulated by hypoxia or drug treatment.

CONCLUSION

We found that a history of graded global hypoxia does not alter the neurotoxic profile of phenobarbital. Levetiracetam, which does not induce cell death in normal developing animals, maintained a benign profile on the background of neonatal hypoxia. We found a sex-based difference, as female animals showed elevated levels of cell death across all treatment conditions. Together, these data address several long-standing gaps in our understanding of the neurotoxic profile of antiseizure medications during early postnatal development.

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.

Relationship of Neonatal Seizure Burden Before Treatment and Response to Initial Antiseizure Medication

OBJECTIVE

To assess among a cohort of neonates with hypoxic-ischemic encephalopathy (HIE) the association of pretreatment maximal hourly seizure burden and total seizure duration with successful response to initial antiseizure medication (ASM).

STUDY DESIGN

This was a retrospective review of data collected from infants enrolled in the HEAL Trial (NCT02811263) between January 25, 2017, and October 9, 2019. We evaluated a cohort of neonates born at ≥36 weeks of gestation with moderate-to-severe HIE who underwent continuous electroencephalogram monitoring and had acute symptomatic seizures. Poisson regression analyzed associations between (1) pretreatment maximal hourly seizure burden, (2) pretreatment total seizure duration, (3) time from first seizure to initial ASM, and (4) successful response to initial ASM.

RESULTS

Among 39 neonates meeting inclusion criteria, greater pretreatment maximal hourly seizure burden was associated with lower chance of successful response to initial ASM (adjusted relative risk for each 5-minute increase in seizure burden 0.83, 95% CI 0.69-0.99). There was no association between pretreatment total seizure duration and chance of successful response. Shorter time-to-treatment was paradoxically associated with lower chance of successful response to treatment, although this difference was small in magnitude (relative risk 1.007, 95% CI 1.003-1.010).

CONCLUSIONS

Maximal seizure burden may be more important than other, more commonly used measures in predicting response to acute seizure treatments.

The Association of Therapeutic Hypothermia With Seizure Burden in Neonates With Hypoxic-Ischemic Encephalopathy

OBJECTIVES

To compare seizure burden between newborn infants treated with therapeutic hypothermia (TH) and those that were not and to compare the need for antiseizure medications (ASM) in a cohort of infants who were diagnosed with neonatal hypoxic-ischemic encephalopathy (HIE).

METHODS

This was a retrospective cohort study on infants born after 35 weeks' gestation, diagnosed with moderate to severe HIE, monitored with amplitude-integrated electroencephalography (aEEG) and eligible for TH. Infants born before the implementation of TH in 2008 were compared with infants born thereafter who received TH. Seizure burden was assessed from aEEG as total time in minutes of seizures activity per hour of recording. Other clinical and demographic data were retrieved from a prospective local database of infants with HIE.

RESULTS

Overall, 149 of 207 infants were included in the study: 112 exposed to TH and 37 not exposed. Cooled infants had a lower seizure burden overall (0.4 vs 2.3 min/h, P < 0.001) and were also less likely to be treated with ASM (74% vs 100%, P < 0.001). In multivariable regression models, not exposed to TH, having a depressed aEEG background, and having higher Apgar scores were associated with higher seizure burden (incidence rate ratio: 4.78 for noncooled infants, P < 0.001); also, not exposed to TH was associated with a higher likelihood of multidrug ASM (odds ratio: 4.83, P < 0.001).

CONCLUSIONS

TH in infants with moderate to severe HIE is associated with significant reduction of seizure burden and ASM therapy.

Acute seizure activity in neonatal inflammation-sensitized hypoxia-ischemia in mice

OBJECTIVE

To examine acute seizure activity and neuronal damage in a neonatal mouse model of inflammation-sensitized hypoxic-ischemic (IS-HI) brain injury utilizing continuous electroencephalography (cEEG) and neurohistology.

METHODS

Neonatal mice were exposed to either IS-HI with Escherichia coli lipopolysaccharide (LPS) or HI alone on postnatal (p) day 10 using unilateral carotid artery ligation followed by global hypoxia (n = 10 [5 female, 5 male] for IS-HI, n = 12 [5 female, 7 male] for HI alone). Video cEEG was recorded for the duration of the experiment and analyzed for acute seizure activity and behavior. Brain tissue was stained and scored based on the degree of neuronal injury in the hippocampus, cortex, and thalamus.

RESULTS

There was no significant difference in acute seizure activity among mice exposed to IS-HI compared to HI with regards to seizure duration (mean = 63 ± 6 seconds for HI vs mean 62 ± 5 seconds for IS-HI, p = 0.57) nor EEG background activity. Mice exposed to IS-HI had significantly more severe neural tissue damage at p30 as measured by neuropathologic scores (mean = 8 ± 1 vs 23 ± 3, p < 0.0001).

INTERPRETATION

In a neonatal mouse model of IS-HI, there was no significant difference in acute seizure activity among mice exposed to IS-HI compared to HI. Mice exposed to IS-HI did show more severe neuropathologic damage at a later age, which may indicate the presence of chronic inflammatory mechanisms of brain injury distinct from acute seizure activity.

Transforming neonatal care with artificial intelligence: challenges, ethical consideration, and opportunities

Artificial intelligence (AI) offers tremendous potential to transform neonatology through improved diagnostics, personalized treatments, and earlier prevention of complications. However, there are many challenges to address before AI is ready for clinical practice. This review defines key AI concepts and discusses ethical considerations and implicit biases associated with AI. Next we will review literature examples of AI already being explored in neonatology research and we will suggest future potentials for AI work. Examples discussed in this article include predicting outcomes such as sepsis, optimizing oxygen therapy, and image analysis to detect brain injury and retinopathy of prematurity. Realizing AI's potential necessitates collaboration between diverse stakeholders across the entire process of incorporating AI tools in the NICU to address testability, usability, bias, and transparency. With multi-center and multi-disciplinary collaboration, AI holds tremendous potential to transform the future of neonatology.

Questions and Controversies in Neonatal Seizures

Neonatal seizures are relatively common, but their diagnosis and management remain challenging. We reviewed the scientific literature on neonatal seizures from July 1973 to November 2023. Several parameters were considered, including pathophysiology, diagnostic criteria, electroencephalographic findings and treatment. Recent classification system of seizures and epilepsies in the newborn, as well as treatment recommendations of neonatal seizures, have been proposed. Nonetheless, the approach to neonatal seizures varies among clinicians and centres, including detection, investigation, treatment and follow-up of patients. There are still many issues on the diagnosis and treatment of neonatal seizures, including the meaning or relevance of some electroencephalographic findings, the precise estimation of the seizure burden, the limited efficacy and side effects risk of antiseizure medications, and the best measures to establish the outcome.

Postischemic Infusion of Apigenin Reduces Seizure Burden in Preterm Fetal Sheep

Seizures are common in preterm newborns and are associated with poor neurodevelopmental outcomes. Current anticonvulsants have poor efficacy, and many have been associated with upregulation of apoptosis in the developing brain. Apigenin, a natural bioactive flavonoid, is a potent inhibitor of hyaluronidase and reduces seizures in adult animal models. However, its impact on perinatal seizures is unclear. In the present study, we examined the effect of apigenin and S3, a synthetic, selective hyaluronidase inhibitor, on seizures after cerebral ischemia in preterm fetal sheep at 0.7 gestation (98-99 days, term ~147 days). Fetuses received sham ischemia (n = 9) or ischemia induced by bilateral carotid occlusion for 25 min. Immediately after ischemia, fetuses received either a continuous infusion of vehicle (0.036% dimethyl sulfoxide, n = 8) or apigenin (50 µM, n = 6). In a pilot study, we also tested infusion of S3 (2 µM, n = 3). Fetuses were monitored continuously for 72 h after ischemia. Infusion of apigenin or S3 were both associated with reduced numbers of animals with seizures, total seizure time, and mean seizure burden. S3 was also associated with a reduction in the total number of seizures over the 72 h recovery period. In animals that developed seizures, apigenin was associated with earlier cessation of seizures. However, apigenin or S3 treatment did not alter recovery of electroencephalographic power or spectral edge frequency. These data support that targeting brain hyaluronidase activity with apigenin or S3 may be an effective strategy to reduce perinatal seizures following ischemia. Further studies are required to determine their effects on neurohistological outcomes.

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.

Continuous Electroencephalography (EEG) Protocol Improves Seizure Detection in Children on Extracorporeal Membrane Oxygenation

BACKGROUND / OBJECTIVE

Seizures are a complication for pediatric patients requiring extracorporeal membrane oxygenation (ECMO). There are no standardized guidelines regarding continuous electroencephalography (EEG) monitoring to detect seizures in these patients, and the impact of protocolized monitoring has not been evaluated. Here we examined the effects of continuous EEG protocol implementation in our pediatric ECMO population.

METHODS

Retrospective chart reviews were conducted on 57 patients who underwent extracorporeal membrane oxygenation and concurrent continuous EEG out of 165 patients supported on extracorporeal membrane oxygenation. Timing of continuous EEG initiation and seizures detected by continuous EEG was determined for 5 years prior to and 15 months after protocol implementation.

RESULTS

Protocol implementation was associated with increased ECMO-supported patients who were concurrently monitored by continuous EEG. Time from ECMO cannulation to continuous EEG initiation was shorter (median 7 hours after versus 16.2 hours before; P < .001). Patients who had ongoing seizures at the start of continuous EEG recording decreased from 64% preprotocol to 0% postprotocol (P < .001), and there was an associated earlier time to break in status epilepticus postprotocol. Seizures were detected past 48 hours after cannulation in 50% of patients in the postprotocol group.

CONCLUSIONS

Protocol implementation resulted in earlier continuous EEG initiation and more EEGs initiated before seizure onset with evidence of altered seizure dynamics. Although current recommendations suggest that continuous EEG duration of 24-48 hours results in seizure detection for >90% of critically ill adults, longer monitoring may be needed to reliably detect seizures in children supported with ECMO, particularly if monitoring is initiated earlier in the post-cannulation period.

Organ dysfunction and mortality in preterm neonates with late-onset bloodstream infection

BACKGROUND

Organ dysfunction (ODF) in late-onset bloodstream infection (LBSI) is associated with increased risk of adverse outcomes. However, no established definition of ODF exists among preterm neonates. Our objective was to describe an outcome-based ODF definition for preterm infants, and assess factors associated with mortality.

METHODS

This is a six-year retrospective study of neonates <35 weeks gestational age, >72 h of age, with non-CONS bacterial/fungal LBSI. Discriminatory ability of each parameter for mortality was evaluated: base deficit ≤-8 mmol/L (BD8), renal dysfunction (urine output <1 cc/kg/h or creatinine ≥100 μmol/L), hypoxic respiratory failure (HRF, ventilated, FiO2 = 1.0), or vasopressor/inotrope use (V/I). Multivariable logistic regression analysis was performed to derive a mortality score.

RESULTS

One hundred and forty-eight infants had LBSI. BD8 had the highest individual predictive ability for mortality (AUROC = 0.78). The combination BD8 + HRF + V/I was used to define ODF (AUROC = 0.84). Fifty-seven (39%) infants developed ODF, among which 28 (49%) died. Mortality increased inversely relative to GA at LBSI-onset (aOR 0.81 [0.67, 0.98]) and directly relative to ODF occurrence (12.15 [4.48, 33.92]). Compared to no-ODF, ODF infants had lower GA and age at illness, and higher frequency of Gram-negative pathogen.

CONCLUSIONS

Among preterm neonates with LBSI, significant metabolic acidosis, HRF, and vasopressor/inotrope use may identify infants high risk for mortality. These criteria could help identify patients for future studies of adjunctive therapies.

IMPACT

Sepsis-related organ dysfunction is associated with increased risk of adverse outcomes. Among preterm neonates, significant metabolic acidosis, use of vasopressors/inotropes, and hypoxic respiratory failure may identify high-risk infants. This can be used to target research and quality improvement efforts toward the most vulnerable infants.

A Descriptive Analysis of Febrile Seizure Hospitalizations in Children with Congenital Heart Disease in the United States

BACKGROUND

Febrile seizure (FS) is the most common convulsive disorder in children. This study analyzed the national proportion of congenital heart disease (CHD) and hospital resource utilization among children admitted for FSs in the U.S.

METHODS

This is a retrospective cross-sectional analysis of pediatric patients up to six years with a primary diagnosis of FS in 2016 and 2019 using the Kids Inpatient Database (KID). The demographic, hospital, and clinical characteristics of children with and without CHD were compared using the chi-square test for categorical variables and linear regressions for continuous variables. Multivariate logistic analysis was conducted to evaluate the impact of CHD on the mean length of hospital stay.

RESULTS

An estimated 10,039 children were admitted with the primary diagnosis of FS. Out of these, 117 (1.2%) had a discharge diagnosis of CHD. The mean age for children with and without CHD was 1.4 years (SD 1.60) and 1.5 years (SD 1.501), respectively. Children with CHD who required hospitalization for FS had longer mean lengths of hospital stay (2.1 days vs. 1.6 days), with an adjusted odd ratio of 0.43 (95% CI: 0.07-0.99; p-value: 0.017). Similarly, the hospital charges for children with CHD were higher than those without CHD ($30,960.28 vs. $21,005.11).

CONCLUSION

Children with CHD who required inpatient admission for FSs in the U.S. were associated with increased length of hospital stay and higher resource utilization when compared with those without CHD. This highlights the need for preventive measures among this vulnerable population.

Evolution of Feeding and Developmental Outcomes in Infants With Moderate Hypoxic-Ischemic Encephalopathy: A Pilot Study

The purpose of the study was to describe the evolution of outcomes among full-term infants with moderate hypoxic-ischemic encephalopathy (HIE); from their early swallowing and feeding abilities during hospitalization, to their later developmental outcomes at 6 and 12 months. Four participants with moderate HIE were recruited. Early feeding and swallowing were assessed using the Neonatal Feeding Assessment Scale and video fluoroscopic swallow studies. Developmental assessments were conducted at 6 and 12 months using the Rossetti Infant-Toddler Language Scale and Vineland-3 Scale. All participants displayed atypical outcomes throughout the study, including oropharyngeal dysphagia initially during hospitalization. All participants were discharged on oral feeds but some breastfeeding difficulties persisted. Variable but pervasive developmental delays were found among all participants at 6 and 12 months. This study emphasizes the need for consistent early intervention from the neonatal period onward, for all infants with moderate HIE. Future studies should use larger cohorts, longer follow-up, and correlational designs.

Antiseizure medication at discharge in infants with hypoxic-ischaemic encephalopathy: an observational study

OBJECTIVES

To assess variability in continuation of antiseizure medication (ASM) at discharge and to evaluate if continuation of ASM at discharge is associated with death or disability among infants with hypoxic-ischaemic encephalopathy (HIE) and seizures.

DESIGN

Retrospective study of infants enrolled in three National Institute of Child Health and Human Development Neonatal Research Network Trials of therapeutic hypothermia.

SETTING

22 US centres.

PATIENTS

Infants with HIE who survived to discharge and had clinical or electrographic seizures treated with ASM.

EXPOSURES

ASM continued or discontinued at discharge.

OUTCOMES

Death or moderate-to-severe disability at 18-22 months, using trial definitions. Multivariable logistic regression evaluated the association between continuation of ASM at discharge and the primary outcome, adjusting for severity of HIE, hypothermia trial treatment arm, use of electroencephalogram, discharge on gavage feeds, Apgar Score at 5 min, birth year and centre.

RESULTS

Of 302 infants included, 61% were continued on ASMs at discharge (range 13%-100% among 22 centres). Electroencephalogram use occurred in 92% of the cohort. Infants with severe HIE comprised 24% and 22% of those discharged with and without ASM, respectively. The risk of death or moderate-to-severe disability was greater for infants continued on ASM at discharge, compared with those infants discharged without ASM (44% vs 28%, adjusted OR 2.14; 95% CI 1.13 to 4.05).

CONCLUSIONS

In infants with HIE and seizures, continuation of ASM at discharge varies substantially among centres and may be associated with a higher risk of death or disability at 18-22 months of age.

Seizure Burden and Neurologic Outcomes After Neonatal Encephalopathy

BACKGROUND AND OBJECTIVES

Seizures are common during neonatal encephalopathy (NE), but the contribution of seizure burden (SB) to outcomes remains controversial. This study aims to examine the relationship between electrographic SB and neurologic outcomes after NE.

METHODS

This prospective cohort study recruited newborns ≥36 weeks postmenstrual age around 6 hours of life between August 2014 and November 2019 from a neonatal intensive care unit (NICU). Participants underwent continuous electroencephalography for at least 48 hours, brain MRI within 3-5 days of life, and structured follow-up at 18 months. Electrographic seizures were identified by board-certified neurophysiologists and quantified as total SB and maximum hourly SB. A medication exposure score was calculated based on all antiseizure medications given during NICU admission. Brain MRI injury severity was classified based on basal ganglia and watershed scores. Developmental outcomes were measured using the Bayley Scales of Infant Development, Third Edition. Multivariable regression analyses were performed, adjusting for significant potential confounders.

RESULTS

Of 108 enrolled infants, 98 had continuous EEG (cEEG) and MRI data collected, of which 5 were lost to follow-up, and 6 died before age 18 months. All infants with moderate-severe encephalopathy completed therapeutic hypothermia. cEEG-confirmed neonatal seizures occurred in 21 (24%) newborns, with a total SB mean of 12.5 ± 36.4 minutes and a maximum hourly SB mean of 4 ± 10 min/h. After adjusting for MRI brain injury severity and medication exposure, total SB was significantly associated with lower cognitive (-0.21, 95% CI -0.33 to -0.08, p = 0.002) and language (-0.25, 95% CI -0.39 to -0.11, p = 0.001) scores at 18 months. Total SB of 60 minutes was associated with 15-point decline in language scores and 70 minutes for cognitive scores. However, SB was not significantly associated with epilepsy, neuromotor score, or cerebral palsy (p > 0.1).

DISCUSSION

Higher SB during NE was independently associated with worse cognitive and language scores at 18 months, even after adjusting for exposure to antiseizure medications and severity of brain injury. These observations support the hypothesis that neonatal seizures occurring during NE independently contribute to long-term outcomes.

Perinatal mortality rate and adverse perinatal outcomes presumably attributable to placental dysfunction in (near) term gestation: A nationwide 5-year cohort study

INTRODUCTION

Placental dysfunction can lead to perinatal hypoxic events including stillbirth. Unless there is overt severe fetal growth restriction, placental dysfunction is frequently not identified in (near) term pregnancy, particularly because fetal size is not necessarily small. This study aimed to evaluate, among (near) term births, the burden of hypoxia-related adverse perinatal outcomes reflected in an association with birth weight centiles as a proxy for placental function.

MATERIAL AND METHOD

A nationwide 5-year cohort of the Dutch national birth registry (PeriNed) including 684,938 singleton pregnancies between 36+0 and 41+6 weeks of gestation. Diabetes, congenital anomalies, chromosomal abnormalities and non-cephalic presentations at delivery were excluded. The main outcome was antenatal mortality rate according to birthweight centiles and gestational age. Secondary outcomes included perinatal hypoxia-related outcomes, including perinatal death and neonatal morbidity, analyzed according to birthweight centiles.

RESULTS

Between 2015 and 2019, 1,074 perinatal deaths (0.16%) occurred in the study population (n = 684,938), of which 727 (0.10%) antenatally. Of all antenatal- and perinatal deaths, 29.4% and 27.9% occurred in birthweights below the 10th centile. The incidence of perinatal hypoxia-related outcomes was highest in fetuses with lowest birthweight centiles (18.0%), falling gradually up to the 50th and 90th centile where the lowest rates of hypoxia-related outcomes (5.4%) were observed.

CONCLUSION

Perinatal hypoxia-related events have the highest incidence in the lowest birthweight centiles but are identifiable throughout the entire spectrum. In fact, the majority of the adverse outcome burden in absolute numbers occurs in the group with a birthweight above the 10th centile. We hypothesize that in most cases these events are attributable to reduced placental function. Additional diagnostic modalities that indicate placental dysfunction at (near) term gestation throughout all birth weight centiles are eagerly wanted.

Bumetanide potentiates the anti-seizure and disease-modifying effects of midazolam in a noninvasive rat model of term birth asphyxia

Birth asphyxia and the resulting hypoxic-ischemic encephalopathy (HIE) are highly associated with perinatal and neonatal death, neonatal seizures, and an adverse later-life outcome. Currently used drugs, including phenobarbital and midazolam, have limited efficacy to suppress neonatal seizures. There is a medical need to develop new therapies that not only suppress neonatal seizures but also prevent later-life consequences. We have previously shown that the loop diuretic bumetanide does not potentiate the effects of phenobarbital in a rat model of birth asphyxia. Here we compared the effects of bumetanide (0.3 or 10 mg/kg i.p.), midazolam (1 mg/kg i.p.), and a combination of bumetanide and midazolam on neonatal seizures and later-life outcomes in this model. While bumetanide at either dose was ineffective when administered alone, the higher dose of bumetanide markedly potentiated midazolam's effect on neonatal seizures. Median bumetanide brain levels (0.47-0.53 µM) obtained with the higher dose were in the range known to inhibit the Na-K-Cl-cotransporter NKCC1 but it remains to be determined whether brain NKCC1 inhibition was underlying the potentiation of midazolam. When behavioral and cognitive alterations were examined over three months after asphyxia, treatment with the bumetanide/midazolam combination, but not with bumetanide or midazolam alone, prevented impairment of learning and memory. Furthermore, the combination prevented the loss of neurons in the dentate hilus and aberrant mossy fiber sprouting in the CA3a area of the hippocampus. The molecular mechanisms that explain that bumetanide potentiates midazolam but not phenobarbital in the rat model of birth asphyxia remain to be determined.

Applications of Artificial Intelligence in Neonatology

The development of artificial intelligence methods has impacted therapeutics, personalized diagnostics, drug discovery, and medical imaging. Although, in many situations, AI clinical decision-support tools may seem superior to rule-based tools, their use may result in additional challenges. Examples include the paucity of large datasets and the presence of unbalanced data (i.e., due to the low occurrence of adverse outcomes), as often seen in neonatal medicine. The most recent and impactful applications of AI in neonatal medicine are discussed in this review, highlighting future research directions relating to the neonatal population. Current AI applications tested in neonatology include tools for vital signs monitoring, disease prediction (respiratory distress syndrome, bronchopulmonary dysplasia, apnea of prematurity) and risk stratification (retinopathy of prematurity, intestinal perforation, jaundice), neurological diagnostic and prognostic support (electroencephalograms, sleep stage classification, neuroimaging), and novel image recognition technologies, which are particularly useful for prompt recognition of infections. To have these kinds of tools helping neonatologists in daily clinical practice could be something extremely revolutionary in the next future. On the other hand, it is important to recognize the limitations of AI to ensure the proper use of this technology.

Association of Hospital Resource Utilization With Neurodevelopmental Outcomes in Neonates With Hypoxic-Ischemic Encephalopathy

IMPORTANCE

Intercenter variation exists in the management of hypoxic-ischemic encephalopathy (HIE). It is unclear whether increased resource utilization translates into improved neurodevelopmental outcomes.

OBJECTIVE

To determine if higher resource utilization during the first 4 days of age, quantified by hospital costs, is associated with survival without neurodevelopmental impairment (NDI) among infants with HIE.

DESIGN, SETTING, AND PARTICIPANTS

Retrospective cohort analysis of neonates with HIE who underwent therapeutic hypothermia (TH) at US children's hospitals participating in the Children's Hospitals Neonatal Database between 2010 and 2016. Data were analyzed from December 2021 to December 2022.

EXPOSURES

Infants who survived to 4 days of age and had neurodevelopmental outcomes assessed at greater than 11 months of age were divided into 2 groups: (1) death or NDI and (2) survived without NDI. Resource utilization was defined as costs of hospitalization including neonatal neurocritical care (NNCC). Data were linked with Pediatric Health Information Systems to quantify standardized costs by terciles.

MAIN OUTCOMES AND MEASURES

The main outcome was death or NDI. Characteristics, outcomes, hospitalization, and NNCC costs were compared.

RESULTS

Among the 381 patients who were included, median (IQR) gestational age was 39 (38-40) weeks; maternal race included 79 (20.7%) Black mothers, 237 (62.2%) White mothers, and 58 (15.2%) mothers with other race; 80 (21%) died, 64 (17%) survived with NDI (combined death or NDI group: 144 patients [38%]), and 237 (62%) survived without NDI. The combined death or NDI group had a higher rate of infants with Apgar score at 10 minutes less than or equal to 5 (65.3% [94 of 144] vs 39.7% [94 of 237]; P < .001) and a lower rate of infants with mild or moderate HIE (36.1% [52 of 144] vs 82.3% [195 of 237]; P < .001) compared with the survived without NDI group. Compared with low-cost centers, there was no association between high- or medium-hospitalization cost centers and death or NDI. High- and medium-EEG cost centers had lower odds of death or NDI compared with low-cost centers (high vs low: OR, 0.30 [95% CI, 0.16-0.57]; medium vs low: OR, 0.29 [95% CI, 0.13-0.62]). High- and medium-laboratory cost centers had higher odds of death or NDI compared with low-cost centers (high vs low: OR, 2.35 [95% CI, 1.19-4.66]; medium vs low: OR, 1.93 [95% CI, 1.07-3.47]). High-antiseizure medication cost centers had higher odds of death or NDI compared with low-cost centers (high vs. low: OR, 3.72 [95% CI, 1.51-9.18]; medium vs low: OR, 1.56 [95% CI, 0.71-3.42]).

CONCLUSIONS AND RELEVANCE

Hospitalization costs during the first 4 days of age in neonates with HIE treated with TH were not associated with neurodevelopmental outcomes. Higher EEG costs were associated with lower odds of death or NDI yet higher laboratory and antiseizure medication costs were not. These findings serve as first steps toward identifying aspects of NNCC that are associated with outcomes.

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.

Effect of neonatal seizure burden and etiology on the long-term outcome: data from a randomized, controlled trial

Background

Neonatal seizures are common, but the impact of neonatal seizures on long-term neurologic outcome remains unclear. We addressed this question by analyzing data from an early-phase controlled trial of bumetanide to treat neonatal seizures.

Methods

Neonatal seizure burden was calculated from continuous video-EEG data. Neurologic outcome was determined by standardized developmental tests and post-neonatal seizure recurrence.

Results

Of 111 enrolled neonates, 43 were randomized to treatment or control groups. There were no differences in neurologic outcome between treatment and control groups. A subgroup analysis was performed for 84 neonates with acute perinatal brain injury (57 HIE, 18 stroke, 9 ICH), most of whom (70%) had neonatal seizures. There was a significant negative correlation between seizure burden and developmental scores (p<0.01). Associations between seizure burden and developmental scores were stronger in HIE and stroke groups compared with ICH (p<0.05).

Conclusion

Bumetanide showed no long-term beneficial or adverse effects, as expected based on treatment duration versus duration of neonatal seizures. For neonates with perinatal brain injury, higher neonatal seizure burden correlated significantly with worse developmental outcome, particularly for ischemic versus hemorrhagic brain injury. These data highlight the need for further investigation of the long-term effects of both neonatal seizure severity and etiology.

Epileptic high-frequency oscillations occur in neonates with a high risk for seizures

Introduction

Scalp high-frequency oscillations (HFOs, 80-250 Hz) are increasingly recognized as EEG markers of epileptic brain activity. It is, however, unclear what level of brain maturity is necessary to generate these oscillations. Many studies have reported the occurrence of scalp HFOs in children with a correlation between treatment success of epileptic seizures and the reduction of HFOs. More recent studies describe the reliable detection of HFOs on scalp EEG during the neonatal period.

Methods

In the present study, continuous EEGs of 38 neonates at risk for seizures were analyzed visually for the scalp HFOs using 30 min of quiet sleep EEG. EEGs of 14 patients were of acceptable quality to analyze HFOs.

Results

The average rate of HFOs was 0.34 ± 0.46/min. About 3.2% of HFOs occurred associated with epileptic spikes. HFOs were significantly more frequent in EEGs with abnormal vs. normal background activities (p = 0.005).

Discussion

Neonatal brains are capable of generating HFOs. HFO could be a viable biomarker for neonates at risk of developing seizures. Our preliminary data suggest that HFOs mainly occur in those neonates who have altered background activity. Larger data sets are needed to conclude whether HFO occurrence is linked to seizure generation and whether this might predict the development of epilepsy.

Adequacy of sedation analgesia to support the comfort of neonates undergoing therapeutic hypothermia and its impact on short-term neonatal outcomes

Objectives

We aimed to evaluate (1) whether sedation analgesia (SA) used during therapeutic hypothermia (TH) was efficient to support the wellbeing of neonates with hypoxic-ischemic encephalopathy, (2) the SA level and its adjustment to clinical pain scores, and (3) the impact of inadequate SA on short-term neonatal outcomes evaluated at discharge.

Methods

This was an observational retrospective study performed between 2011 and 2018 in two level III centers in Alsace, France. We analyzed the wellbeing of infants by using the COMFORT-Behavior (COMFORT-B) clinical score and SA level during TH, according to which we classified infants into four groups: those with excess SA, adequate SA, lack of SA, and variability of SA. We analyzed the variations in doses of SA and their justification. We also determined the impact of inadequate SA on neonatal outcomes at discharge by multivariate analyses with multinomial regression, with adequate SA as the reference.

Results

A total of 110 patients were included, 89 from Strasbourg university hospital and 21 from Mulhouse hospital. The COMFORT-B score was assessed 95.5% of the time. Lack of SA was mainly found on the first day of TH (15/110, 14%). In all, 62 of 110 (57%) infants were in excess of SA over the entire duration of TH. Most dose variations were related to clinical pain scores. Inadequate SA was associated with negative short-term consequences. Infants with excess of SA had a longer duration of mechanical ventilation [mean ratio 1.46, 95% confidence interval (CI), 1.13-1.89, p = 0.005] and higher incidence of abnormal neurological examination at discharge (odds ratio 2.61, 95% CI, 1.10-6.18, p = 0.029) than infants with adequate SA.

Discussion

Adequate SA was not easy to achieve during TH. Close and regular monitoring of SA level may help achieve adequate SA. Excess of SA can be harmful for newborns with hypoxic-ischemic encephalopathy who are undergoing TH.

Optimal neuromonitoring techniques in neonates with hypoxic ischemic encephalopathy

Neonates with hypoxic ischemic encephalopathy (HIE) are at significant risk for adverse outcomes including death and neurodevelopmental impairment. Neuromonitoring provides critical diagnostic and prognostic information for these infants. Modalities providing continuous monitoring include continuous electroencephalography (cEEG), amplitude-integrated electroencephalography (aEEG), near-infrared spectroscopy (NIRS), and heart rate variability. Serial bedside neuromonitoring techniques include cranial ultrasound and somatic and visual evoked potentials but may be limited by discrete time points of assessment. EEG, aEEG, and NIRS provide distinct and complementary information about cerebral function and oxygen utilization. Integrated use of these neuromonitoring modalities in addition to other potential techniques such as heart rate variability may best predict imaging outcomes and longer-term neurodevelopment. This review examines available bedside neuromonitoring techniques for the neonate with HIE in the context of therapeutic hypothermia.

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.

Optical Monitoring in Neonatal Seizures

BACKGROUND

Neonatal seizures remain a significant cause of morbidity and mortality worldwide. The past decade has resulted in substantial progress in seizure detection and understanding the impact seizures have on the developing brain. Optical monitoring such as cerebral near-infrared spectroscopy (NIRS) and broadband NIRS can provide non-invasive continuous real-time monitoring of the changes in brain metabolism and haemodynamics.

AIM

To perform a systematic review of optical biomarkers to identify changes in cerebral haemodynamics and metabolism during the pre-ictal, ictal, and post-ictal phases of neonatal seizures.

METHOD

A systematic search was performed in eight databases. The search combined the three broad categories: (neonates) AND (NIRS) AND (seizures) using the stepwise approach following PRISMA guidance.

RESULTS

Fifteen papers described the haemodynamic and/or metabolic changes observed with NIRS during neonatal seizures. No randomised controlled trials were identified during the search. Studies reported various changes occurring in the pre-ictal, ictal, and post-ictal phases of seizures.

CONCLUSION

Clear changes in cerebral haemodynamics and metabolism were noted during the pre-ictal, ictal, and post-ictal phases of seizures in neonates. Further studies are necessary to determine whether NIRS-based methods can be used at the cot-side to provide clear pathophysiological data in real-time during neonatal seizures.

Validation of central nervous system-induced seizures and other neurological variables in the Swedish Neonatal Quality Register

Aim

We sought to validate neurological variables and relevant International Classification of Diseases, Tenth Revision (ICD‐10) codes in the Swedish Neonatal Quality (SNQ) Register.

Methods

Register data were collected for 351 neonates, born between January 2009 and December 2016, who were treated at a neonatal unit in the Stockholm region on 385 occasions. They were eligible if the check‐box for central nervous system (CNS)‐induced seizures was ticked. The Register data, including relevant ICD‐10 codes, were validated by checking the patients' electronic medical charts.

Results

Most of the neonates were born at term (76%) and weighed >2500 g (80%). The variable CNS‐induced seizures had a positive predictive value of 46%. The ICD‐10 diagnosis P90.9A had a positive predictive value of 90%. This comprises seizures validated with electroencephalography, amplitude‐integrated electroencephalography or continuous function monitoring. The majority of the associated neurological variables in the Register had positive predictive values above 85%.

Conclusion

When the check‐box was ticked for central nervous system‐induced seizures, most of the neurological variables in the Register had high validity. However, the CNS‐induced seizures variable per se had a lower positive predictive value. Future SNQ Register‐based studies of such neonatal seizures should also include ICD‐10 P90.9A.

Outcome of non-cooled asphyxiated infants with under-recognised or delayed-onset encephalopathy

OBJECTIVE

To describe the clinical characteristics, MRI findings and neurodevelopmental outcome of infants with documented perinatal asphyxia and seizure onset within 24 hours after birth who were not selected for therapeutic hypothermia (TH).

DESIGN

Retrospective cohort study.

SETTING AND PATIENTS

(Near-)term infants with documented perinatal asphyxia referred to two Dutch level III neonatal units with neonatal encephalopathy (NE) and seizures <24 hours after birth not treated with TH. Infants with a diagnosis other than NE following perinatal asphyxia causing the seizures were excluded.

MAIN OUTCOME MEASURES

Clinical characteristics, findings on cranial MRI performed within 8 days after birth and neurodevelopmental outcome assessed using the Griffiths Mental Development Scales at 18 months or Bayley Scales of Infant and Toddler Development-Third Edition at 2 years of age.

RESULTS

39 infants were included. All had abnormalities on MRI. Predominant white matter/watershed injury was the most common pattern of injury, 23 (59%). 7 (18%) infants had predominant basal ganglia/thalamus injury, 3 (8%) near total brain injury, 5 (13%) arterial ischaemic stroke, 1 (3%) an intraventricular haemorrhage. Adverse outcome was seen in 51%: 6 died, 11 developed cerebral palsy (spastic n=8, dyskinetic n=3), 2 had neurodevelopmental delay, 1 had severe hearing impairment.

CONCLUSIONS

All infants with documented perinatal asphyxia and seizure onset within 24 hours after birth who did not receive TH had abnormalities on MRI. 51% had an adverse outcome. Better methods for recognition of infants who might benefit from TH and careful neurodevelopmental follow-up are urgently needed.

Diagnosis and Management of Seizures in the Preterm Infant

The risk of seizure is increased in premature neonates compared to full term infants, with a distinct profile of etiologies, timing and character. Despite improvements in neonatal care, preterm infants with seizure continue to have higher risk of abnormal neurodevelopmental outcomes when compared to preterm infants without seizures, or to full term infants with seizures. Very limited evidence guides the care of this challenging population, therefore, management of the preterm neonate with seizure is largely extrapolated from the care of full-term neonates. A critical need exists for well-designed clinical trials investigating and validating the safety, efficacy, and outcomes of seizure management in this vulnerable population.

Impact of COVID-19 Pandemic on Developmental Service Delivery in Children With a History of Neonatal Seizures

BACKGROUND

Children with a history of acute provoked neonatal seizures are at high risk for disability, often requiring developmental services. The coronavirus disease 2019 (COVID-19) pandemic has led to widespread changes in how health care is delivered. Our objective was to determine the magnitude of service interruption of among children born between October 2014 and December 2017 and enrolled in the Neonatal Seizure Registry (NSR), a nine-center collaborative of pediatric centers in the United States.

METHODS

This is a prospective cohort study of children with acute provoked seizures with onset ≤44 weeks' gestation and evaluated at age three to six years. Parents of children enrolled in the NSR completed a survey about their child's access to developmental services between June 2020 and April 2021.

RESULTS

Among 144 children enrolled, 72 children (50%) were receiving developmental services at the time of assessment. Children receiving services were more likely to be male, born preterm, and have seizure etiology of infection or ischemic stroke. Of these children, 64 (89%) experienced a disruption in developmental services due to the pandemic, with the majority of families (n = 47, 73%) reporting that in-person services were no longer available.

CONCLUSIONS

Half of children with acute provoked neonatal seizures were receiving developmental services at ages three to six years. The COVID-19 pandemic has led to widespread changes in delivery of developmental services. Disruptions in services have the potential to impact long-term outcomes for children who rely on specialized care programs to optimize mobility and learning.

Neonatal Seizure Management: Is the Timing of Treatment Critical?

OBJECTIVE

To assess the impact of the time to treatment of the first electrographic seizure on subsequent seizure burden and describe overall seizure management in a large neonatal cohort.

STUDY DESIGN

Newborns (36-44 weeks of gestation) requiring electroencephalographic (EEG) monitoring recruited to 2 multicenter European studies were included. Infants who received antiseizure medication exclusively after electrographic seizure onset were grouped based on the time to treatment of the first seizure: antiseizure medication within 1 hour, between 1 and 2 hours, and after 2 hours. Outcomes measured were seizure burden, maximum seizure burden, status epilepticus, number of seizures, and antiseizure medication dose over the first 24 hours after seizure onset.

RESULTS

Out of 472 newborns recruited, 154 (32.6%) had confirmed electrographic seizures. Sixty-nine infants received antiseizure medication exclusively after the onset of electrographic seizure, including 21 infants within 1 hour of seizure onset, 15 between 1 and 2 hours after seizure onset, and 33 at >2 hours after seizure onset. Significantly lower seizure burden and fewer seizures were noted in the infants treated with antiseizure medication within 1 hour of seizure onset (P = .029 and .035, respectively). Overall, 258 of 472 infants (54.7%) received antiseizure medication during the study period, of whom 40 without electrographic seizures received treatment exclusively during EEG monitoring and 11 with electrographic seizures received no treatment.

CONCLUSIONS

Treatment of neonatal seizures may be time-critical, but more research is needed to confirm this. Improvements in neonatal seizure diagnosis and treatment are also needed.

Risk Factors for Clinical Seizures in Neonates with Hypoxic-ischemic Encephalopathy Treated with Therapeutic Hypothermia

BACKGROUND

This study aimed to assess the risk factors for clinical seizures in newborns treated with whole body cooling (WBC) for hypoxic ischemic encephalopathy (HIE).

METHODS

Infants with gestational age≥36 weeks and birth weight≥2.000 g who were treated with WBC due to HIE were retrospectively enrolled in this study. Patients were assigned to two groups: infants without clinical seizures (Group 1) and infants with clinical seizures (Group 2). The two groups were compared to determine the risk factors for the occurrence of clinical seizures.

RESULTS

A total of 25 patients (Group 1=10 and Group 2=15) were included in the study. Prothrombin time (PT) was determined as independent risk factor for clinical seizures (p=0.046) and the odds ratio for the effect of PT was found as 1.475 (%95 CI:1.006-2.299). PT (area under the curve [AUC]=0.764; p=0.041), and increased cardiac troponin-I (cTnI) (AUC=0.935; p=0.002) were found to be significant risk factors for predicting the occurrence of clinical seizures. The optimal PT cut-off value was 22.7 sec, with a sensitivity and specificity of 45.4% and 90%, respectively; as well as positive and negative predictive value of 83.3% and 60.0%, respectively. The chest compression in the delivery room, severely abnormal amplitude integrated electroencephalography and high encephalopathy score were also found risk factors for occurrence of clinical seizures.

CONCLUSION

Chest compression in the delivery room, high encephalopathy score, prolonged PT, and increased cTnI are significant factors for clinical seizures in newborns treated with WBC for HIE.

Seizure Severity and Treatment Response in Newborn Infants with Seizures Attributed to Intracranial Hemorrhage

OBJECTIVE

We sought to characterize intracranial hemorrhage (ICH) as a seizure etiology in infants born term and preterm. For infants born term, we sought to compare seizure severity and treatment response for multisite vs single-site ICH and hypoxic-ischemic encephalopathy (HIE) with vs without ICH.

STUDY DESIGN

We studied 112 newborn infants with seizures attributed to ICH and 201 infants born at term with seizures attributed to HIE, using a cohort of consecutive infants with clinically diagnosed and/or electrographic seizures prospectively enrolled in the multicenter Neonatal Seizure Registry. We compared seizure severity and treatment response among infants with complicated ICH, defined as multisite vs single-site ICH and HIE with vs without ICH.

RESULTS

ICH was a more common seizure etiology in infants born preterm vs term (27% vs 10%, P < .001). Most infants had subclinical seizures (74%) and an incomplete response to initial antiseizure medication (ASM) (68%). In infants born term, multisite ICH was associated with more subclinical seizures than single-site ICH (93% vs 66%, P = .05) and an incomplete response to the initial ASM (100% vs 66%, P = .02). Status epilepticus was more common in HIE with ICH vs HIE alone (38% vs 17%, P = .05).

CONCLUSIONS

Seizure severity was greater and treatment response was lower among infants born term with complicated ICH. These data support the use of continuous video electroencephalogram monitoring to accurately detect seizures and a multistep treatment plan that considers early use of multiple ASMs, particularly with parenchymal and high-grade intraventricular hemorrhage and complicated ICH.

Optical Flow Estimation Improves Automated Seizure Detection in Neonatal EEG

PURPOSE

Existing automated seizure detection algorithms report sensitivities between 43% and 77% and specificities between 56% and 90%. The algorithms suffer from false alarms when applied to neonatal EEG because of the high degree of nurse handling and rhythmic patting used to soothe neonates. Computer vision technology that quantifies movement in real time could distinguish artifactual motion and improve automated neonatal seizure detection algorithms.

METHODS

The authors used video EEG recordings from 43 neonates undergoing monitoring for seizures as part of the NEOLEV2 clinical trial. The Persyst neonatal automated seizure detection algorithm ran in real time during study EEG acquisitions. Computer vision algorithms were applied to extract detailed accounts of artifactual movement of the neonate or people near the neonate though dense optical flow estimation.

RESULTS

Using the methods mentioned above, 197 periods of patting activity were identified and quantified, of which 45 generated false-positive automated seizure detection events. A binary patting detection algorithm was trained with a subset of 470 event videos. This supervised detection algorithm was applied to a testing subset of 187 event videos with 8 false-positive events, which resulted in a 24% reduction in false-positive automated seizure detections and a 50% reduction in false-positive events caused by neonatal care patting, while maintaining 11 of 12 true-positive seizure detection events.

CONCLUSIONS

This work presents a novel approach to improving automated seizure detection algorithms used during neonatal video EEG monitoring. This artifact detection mechanism can improve the ability of a seizure detector algorithm to distinguish between artifact and true seizure activity.

Early-life seizures modify behavioral response to ultrasonic vocalization playback in adult rats

Early-life seizures (ELS) are associated with autism spectrum disorder (ASD); however, due to a lack of effective treatments for ELS, it is not clear whether ELS plays a causal role, potentiates the ASD phenotype, or is the result of a common pathophysiology. Deficits in communications are a core feature of ASD. To isolate the impact of ELS on communication, we probed the behavioral consequences of a single episode of kainic acid-induced early-life seizures (KA-ELS) in male and female Sprague-Dawley (CD) rats. Deficits in auditory communication were observed in adult male rats as assessed by behavioral response to ultrasonic vocalization (USV) playback. Ultrasonic vocalizations are classified into two major categories - 50-kHz (positive) calls and 22-kHz (aversive) calls. Behavioral response was assessed via rat preference for different USV playback in a radial arm maze. Response to 22-kHz calls was not impacted by ELS while response to 50-kHz calls was impacted. All rats demonstrated positional preference for the arms adjacent to where 50-kHz calls were playing compared to background noise; however, male ELS rats demonstrated a greater positional preference for the arms adjacent to where 50-kHz calls were playing compared to male control rats. These studies demonstrate that responses to socially relevant auditory cues are chronically altered in adult male rats following a single episode of ELS. We speculate that these changes contribute to previously reported social deficits associated with ELS.

Seizures' impact on cognition and quality of life in childhood cancer survivors

BACKGROUND

The objective of this study was to determine the impact of seizure-related factors on neurocognitive, health-related quality of life (HRQOL), and social outcomes in survivors of childhood cancer.

METHODS

Survivors of childhood cancer treated at St. Jude Children's Hospital (n = 2022; 48.3% female; median age, 31.5 years; median time since diagnosis, 23.6 years) completed neurocognitive testing and questionnaires. The presence, severity, resolution, and treatment history of seizures were abstracted from medical records. Adjusting for the age at diagnosis, sex, and prior cancer therapy, multivariable models examined the impact of seizures on neurocognitive and HRQOL outcomes. Mediation analyses were conducted for social outcomes.

RESULTS

Seizures were identified in 232 survivors (11.5%; 29.9% of survivors with central nervous system [CNS] tumors and 9.0% of those without CNS tumors). In CNS tumor survivors, seizures were associated with poorer executive function and processing speed (P < .02); in non-CNS tumor survivors, seizures were associated with worse function in every domain (P < .05). Among non-CNS survivors, seizure severity was associated with worse processing speed (P = .023), and resolution was associated with better executive function (P = .028) and attention (P = .044). In CNS survivors, seizure resolution was associated with improved attention (P = .047) and memory (P < .02). Mediation analysis revealed that the impact of seizures on social outcomes was mediated by neurocognitive function.

CONCLUSIONS

Seizures in cancer survivors adversely affect long-term functional and psychosocial outcomes independently of cancer therapy. The resolution of seizure occurrence is associated with better outcomes. Seizure severity is associated with poorer outcomes and should be a focus of clinical management and patient education.

Outcomes of neonatal hypoxic-ischaemic encephalopathy in centres with and without active therapeutic hypothermia: a nationwide propensity score-matched analysis

OBJECTIVE

Therapeutic hypothermia (TH) for neonatal hypoxic-ischaemic encephalopathy (HIE), delivered mainly in tertiary cooling centres (CCs), reduces mortality and neurodisability. It is unknown if birth in a non-cooling centre (non-CC), without active TH, impacts short-term outcomes.

DESIGN

Retrospective cohort study using National Neonatal Research Database and propensity score-matching.

SETTING

UK neonatal units.

PATIENTS

Infants ≥36 weeks gestational age with moderate or severe HIE admitted 2011-2016.

INTERVENTIONS

Birth in non-CC compared with CC.

MAIN OUTCOME MEASURES

Primary outcome was survival to discharge without recorded seizures. Secondary outcomes were recorded seizures, mortality and temperature on arrival at CCs following transfer.

RESULTS

5059 infants were included with 2364 (46.7%) born in non-CCs. Birth in a CC was associated with improved survival without seizures (35.1% vs 31.8%; OR 1.15, 95% CI 1.02 to 1.31; p=0.02), fewer seizures (60.7% vs 64.6%; OR 0.84, 95% CI 0.75 to 0.95, p=0.007) and similar mortality (15.8% vs 14.4%; OR 1.11, 95% CI 0.93 to 1.31, p=0.20) compared with birth in a non-CC. Matched infants from level 2 centres only had similar results, and birth in CCs was associated with greater seizure-free survival compared with non-CCs. Following transfer from a non-CC to a CC (n=2027), 1362 (67.1%) infants arrived with a recorded optimal therapeutic temperature but only 259 (12.7%) of these arrived within 6 hours of birth.

CONCLUSIONS

Almost half of UK infants with HIE were born in a non-CC, which was associated with suboptimal hypothermic treatment and reduced seizure-free survival. Provision of active TH in non-CC hospitals prior to upward transfer warrants consideration.

Outcome Prediction in Neonatal Hypoxic-Ischaemic Encephalopathy Using Neurophysiology and Neuroimaging

OBJECTIVE

The aim of the study was to determine the predictive power of the combined use of neurophysiological (amplitude-integrated electroencephalography [aEEG], near-infrared spectroscopy [NIRS]) methods and neuroimaging (magnetic resonance imaging [MRI]) for long-term outcome prediction in neonates with hypoxic-ischaemic encephalopathy (HIE).

STUDY DESIGN

Prospective cohort study of 56 patients with moderate to severe HIE and hypothermia treatment at the Medical University of Vienna between 2008 and 2020. aEEG and NIRS were recorded continuously over a period of >4 days (102 h) starting at the initiation of hypothermia treatment, MRI was performed at a median age of 8 days. Receiver operating characteristic curves and area under the curve were calculated to evaluate the prognostic ability of aEEG, NIRS, and MRI parameters for outcome assessed via Bayley Scales of Infant Development 3rd edition at 2 years of age.

RESULTS

Combined aEEG and MRI parameters showed highest predictive power regarding long-term outcome. The highest area under the curve values (0.96-0.99) were obtained for aEEG (combination of background pattern and sleep-wake cycling) between 66 and 102 h after initiation of hypothermia in combination with MRI findings. NIRS parameters did not differ significantly between infants with favourable and adverse outcome.

CONCLUSIONS

Combined aEEG and MRI parameter scores were more predictive than single parameter scores. No further improvement was observed when combining aEEG/MRI with NIRS data.

Brain temperature monitoring in newborn infants: Current methodologies and prospects

Brain tissue temperature is a dynamic balance between heat generation from metabolism, passive loss of energy to the environment, and thermoregulatory processes such as perfusion. Perinatal brain injuries, particularly neonatal encephalopathy, and seizures, have a significant impact on the metabolic and haemodynamic state of the developing brain, and thereby likely induce changes in brain temperature. In healthy newborn brains, brain temperature is higher than the core temperature. Magnetic resonance spectroscopy (MRS) has been used as a viable, non-invasive tool to measure temperature in the newborn brain with a reported accuracy of up to 0.2 degrees Celcius and a precision of 0.3 degrees Celcius. This measurement is based on the separation of chemical shifts between the temperature-sensitive water peaks and temperature-insensitive singlet metabolite peaks. MRS thermometry requires transport to an MRI scanner and a lengthy single-point measurement. Optical monitoring, using near infrared spectroscopy (NIRS), offers an alternative which overcomes this limitation in its ability to monitor newborn brain tissue temperature continuously at the cot side in real-time. Near infrared spectroscopy uses linear temperature-dependent changes in water absorption spectra in the near infrared range to estimate the tissue temperature. This review focuses on the currently available methodologies and their viability for accurate measurement, the potential benefits of monitoring newborn brain temperature in the neonatal intensive care unit, and the important challenges that still need to be addressed.

Effect of Treatment of Clinical Seizures vs Electrographic Seizures in Full-Term and Near-Term Neonates: A Randomized Clinical Trial

IMPORTANCE

Seizures in the neonatal period are associated with increased mortality and morbidity. Bedside amplitude-integrated electroencephalography (aEEG) has facilitated the detection of electrographic seizures; however, whether these seizures should be treated remains uncertain.

OBJECTIVE

To determine if the active management of electrographic and clinical seizures in encephalopathic term or near-term neonates improves survival free of severe disability at 2 years of age compared with only treating clinically detected seizures.

DESIGN, SETTING, AND PARTICIPANTS

This randomized clinical trial was conducted in tertiary newborn intensive care units recruited from 2012 to 2016 and followed up until 2 years of age. Participants included neonates with encephalopathy at 35 weeks' gestation or more and younger than 48 hours old. Data analysis was completed in April 2021.

INTERVENTIONS

Randomization was to an electrographic seizure group (ESG) in which seizures detected on aEEG were treated in addition to clinical seizures or a clinical seizure group (CSG) in which only seizures detected clinically were treated.

MAIN OUTCOMES AND MEASURES

Primary outcome was death or severe disability at 2 years, defined as scores in any developmental domain more than 2 SD below the Australian mean assessed with Bayley Scales of Neonate and Toddler Development, 3rd ed (BSID-III), or the presence of cerebral palsy, blindness, or deafness. Secondary outcomes included magnetic resonance imaging brain injury score at 5 to 14 days, time to full suck feeds, and individual domain scores on BSID-III at 2 years.

RESULTS

Of 212 randomized neonates, the mean (SD) gestational age was 39.2 (1.7) weeks and 122 (58%) were male; 152 (72%) had moderate to severe hypoxic-ischemic encephalopathy (HIE) and 147 (84%) had electrographic seizures. A total of 86 neonates were included in the ESG group and 86 were included in the CSG group. Ten of 86 (9%) neonates in the ESG and 4 of 86 (4%) in the CSG died before the 2-year assessment. The odds of the primary outcome were not significantly different in the ESG group compared with the CSG group (ESG, 38 of 86 [44%] vs CSG, 27 of 86 [31%]; odds ratio [OR], 1.83; 95% CI, 0.96 to 3.49; P = .14). There was also no significant difference in those with HIE (OR, 1.77; 95% CI, 0.84 to 3.73; P = .26). There was evidence that cognitive outcomes were worse in the ESG (mean [SD] scores, ESG: 97.4 [17.7] vs CSG: 103.8 [17.3]; mean difference, -6.5 [95% CI, -1.2 to -11.8]; P = .01). There was little evidence of a difference in secondary outcomes, including time to suck feeds, seizure burden, or brain injury score.

CONCLUSIONS AND RELEVANCE

Treating electrographic and clinical seizures with currently used anticonvulsants did not significantly reduce the rate of death or disability at 2 years in a heterogeneous group of neonates with seizures.

TRIAL REGISTRATION

http://anzctr.org.au Identifier: ACTRN12611000327987.

Expanding Access to Continuous EEG Monitoring in Neonatal Intensive Care Units

PURPOSE

Neonatal seizures are common and difficult to identify clinically because the majority are subclinical and correct identification of electroclinical seizures based on semiology is unreliable. Therefore, continuous EEG monitoring (CEEG) is critical for seizure identification in neonates and is recommended as the gold standard method in American Clinical Neurophysiology Society guidelines. Despite these recommendations, barriers to implementing widespread CEEG exist.

METHODS

To expand access to CEEG for at-risk neonates, a framework for providing remote CEEG was established at two network hospital neonatal intensive care units. Utilization and clinical impact were tracked as a quality improvement study.

RESULTS

In a 27-month period from June 2017 through September 2019, 76 neonates underwent CEEG between the two network neonatal intensive care units. Electrographic seizures occurred in about one quarter of records (18/76; 24%), though their incidence varied by CEEG indication. Care notes indicated that CEEG impacted clinical care in three quarters of cases (57/76; 75%). Continuous EEG impacted decisions to treat with anti-seizure medications in approximately one half of patients (impact: 28/57 [49%]; no impact 29/57 [51%]), and CEEG impacted prognostic discussions in approximately two thirds of patients (impact: 39/57 [68%]; no impact 18/57 [32%]).

CONCLUSIONS

Establishment of a remote CEEG program for neonates is feasible, effective at identifying seizures, and improves the quality of care provided to neonates hospitalized at these network hospitals.

Expediting Treatment of Seizures in the Intensive Care Nursery

OBJECTIVES

Prolonged neonatal seizures are associated with poor neurodevelopmental outcomes. The aim of this quality improvement project was to decrease the time to medical treatment of seizures by 45% within 15 months for neonates admitted to the intensive care nursery (ICN) in an academic children's hospital.

METHODS

A multidisciplinary team developed key drivers for timely treatment of seizures. Targeted interventions included optimizing a seizure rescue process with a mechanism that brings a pharmacist to the bedside for expedited medication delivery, in addition to interactive educational sessions. The outcome measure was time from the decision to treat seizures to medication administration. The process measure was use of the seizure rescue process with a balancing measure of unnecessary activations of this process. Data were collected from monthly chart review and displayed on statistical process control charts for analysis. The intervention period was from January 2019 to March 2020.

RESULTS

Between January 2016 and March 2020, there were 203 seizure treatment events (160 preintervention and 43 postintervention) in the ICN. Time to treatment of neonatal seizures decreased by 48%, from a baseline of 27 minutes (January 2016 to December 2018) to 14 minutes by March 2020, which reflected significant and sustained improvement. This was associated with improvement in the process metric during the same time periods. Unnecessary seizure rescue process activations were stable postintervention.

CONCLUSIONS

Implementation of an innovative seizure rescue process, in conjunction with staff and provider education, expedited antiseizure therapy in the ICN without requiring code resources.