Electrographic seizures in neonates correlate with poor neurodevelopmental outcome

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.

Neurological outcomes and mortality after neonatal seizures with electroencephalographical verification. A systematic review

AIM

To conduct a systematic review of post-neonatal neurological outcomes and mortality following neonatal seizures with electroencephalographical verification.

METHODS

The databases Medline, Embase and Web of Science were searched for eligible studies. All abstracts were screened in a blinded fashion between research team members and reports found eligible were obtained and screened in full text by two members each. From studies included, outcome results for post-neonatal epilepsy, cerebral palsy, intellectual disability, developmental delay, mortality during and after the neonatal period and composite outcomes were extracted. A quality assessment of each study was performed.

RESULTS

In total, 5518 records were screened and 260 read in full text. Subsequently, 31 studies were included, containing cohorts of either mixed or homogenous etiologies. Follow-up time and gestational ages varied between studies. No meta-analysis could be performed due to the low number of studies with comparable outcomes and effect measures. Reported cumulative incidences of outcomes varied greatly between studies. For post-neonatal epilepsy the reported incidence was 5-84%, for cerebral palsy 9-78%, for intellectual disability 24-67%, for developmental delay 10-67% and for mortality 1-62%. Subgroup analysis had more coherent results and in cohorts with status epilepticus a higher incidence of post-neonatal epilepsy from 46 to 84% was shown.

CONCLUSION

The large variation of reported incidences for neurological outcomes and mortality found even when restricting to cohorts with electroencephalographically verified neonatal seizures indicates selection bias as a significant confounder in existing studies. Population-based approaches are thus warranted to correctly predict outcomes in this group.

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.

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.

Treatment of seizures in the neonate: Guidelines and consensus-based recommendations-Special report from the ILAE Task Force on Neonatal Seizures

Seizures are common in neonates, but there is substantial management variability. The Neonatal Task Force of the International League Against Epilepsy (ILAE) developed evidence-based recommendations about antiseizure medication (ASM) management in neonates in accordance with ILAE standards. Six priority questions were formulated, a systematic literature review and meta-analysis were performed, and results were reported following the PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) 2020 standards. Bias was evaluated using the Cochrane tool and risk of Bias in non-randomised studies - of interventions (ROBINS-I), and quality of evidence was evaluated using grading of recommendations, assessment, development and evaluation (GRADE). If insufficient evidence was available, then expert opinion was sought using Delphi consensus methodology. The strength of recommendations was defined according to the ILAE Clinical Practice Guidelines development tool. There were six main recommendations. First, phenobarbital should be the first-line ASM (evidence-based recommendation) regardless of etiology (expert agreement), unless channelopathy is likely the cause for seizures (e.g., due to family history), in which case phenytoin or carbamazepine should be used. Second, among neonates with seizures not responding to first-line ASM, phenytoin, levetiracetam, midazolam, or lidocaine may be used as a second-line ASM (expert agreement). In neonates with cardiac disorders, levetiracetam may be the preferred second-line ASM (expert agreement). Third, following cessation of acute provoked seizures without evidence for neonatal-onset epilepsy, ASMs should be discontinued before discharge home, regardless of magnetic resonance imaging or electroencephalographic findings (expert agreement). Fourth, therapeutic hypothermia may reduce seizure burden in neonates with hypoxic-ischemic encephalopathy (evidence-based recommendation). Fifth, treating neonatal seizures (including electrographic-only seizures) to achieve a lower seizure burden may be associated with improved outcome (expert agreement). Sixth, a trial of pyridoxine may be attempted in neonates presenting with clinical features of vitamin B6-dependent epilepsy and seizures unresponsive to second-line ASM (expert agreement). Additional considerations include a standardized pathway for the management of neonatal seizures in each neonatal unit and informing parents/guardians about the diagnosis of seizures and initial treatment options.

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.

Efficacy and safety of ketamine for neonatal refractory status epilepticus: case report and systematic review

Background

Evidence-based data on treatment of neonatal status epilepticus (SE) are scarce. We aimed to collect data on the efficacy and safety of ketamine for the treatment of neonatal SE and to assess its possible role in the treatment of neonatal SE.

Methods

We described a novel case and conducted a systematic literature review on neonatal SE treated with ketamine. The search was carried out in Pubmed, Cochrane, Clinical Trial Gov, Scopus and Web of Science.

Results

Seven published cases of neonatal SE treated with ketamine were identified and analyzed together with our novel case. Seizures typically presented during the first 24 h of life (6/8). Seizures were resistant to a mean of five antiseizure medications. Ketamine, a NMDA receptor antagonist, appeared to be safe and effective in all neonates treated. Neurologic sequelae including hypotonia and spasticity were reported for 4/5 of the surviving children (5/8). 3/5 of them were seizure free at 1-17 months of life.

Discussion

Neonatal brain is more susceptible to seizures due to a shift towards increased excitation because of a paradoxical excitatory effect of GABA, a greater density of NMDA receptors and higher extracellular concentrations of glutamate. Status epilepticus and neonatal encephalopathy could further enhance these mechanisms, providing a rationale for the use of ketamine in this setting.

Conclusions

Ketamine in the treatment of neonatal SE showed a promising efficacy and safety profile. However, further in-depth studies and clinical trials on larger populations are needed.

All Care is Brain Care: Neuro-Focused Quality Improvement in the Neonatal Intensive Care Unit

Neonates requiring intensive care are in a critical period of brain development that coincides with the neonatal intensive care unit (NICU) hospitalization, placing these infants at high risk of brain injury and long-term neurodevelopmental impairment. Care in the NICU has the potential to be both harmful and protective to the developing brain. Neuro-focused quality improvement efforts address 3 main pillars of neuroprotective care: prevention of acquired injury, protection of normal maturation, and promotion of a positive environment. Despite challenges in measurement, many centers have shown success with consistent implementation of best and potentially better practices that may improve markers of brain health and neurodevelopment.

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.

The Impact of Phenobarbital on the Ability of Electroencephalogram to Predict Adverse Outcome in Asphyxiated Neonates during Therapeutic Hypothermia

OBJECTIVE

 Classification of electroencephalogram (EEG) background has been established to predict outcome in neonates with hypoxic ischemic encephalopathy (HIE). However, the impact of phenobarbital therapy on the predictability of EEG background has not been studied. Our objective is to determine if EEG background after treatment with phenobarbital during therapeutic hypothermia (TH) remains a good predictor for brain injury in neonates with HIE.

STUDY DESIGN

 This is a single-center, retrospective study of consecutive neonates with HIE who underwent TH and EEG monitoring from October 2017 to March 2021. Per institutional protocol, all infants received a dose of prophylactic phenobarbital and bumetanide therapy at the onset of TH for sedative and neuroprotective measures. The initial 3 hours of EEG background activity was classified based on national guidelines. Infants were separated into two groups based on EEG background scores: group 1 (normal-mild, n = 30) and group 2 (moderate-severe, n = 36). Brain magnetic resonance imaging (MRI) results were scored based on the National Institute of Child Health and Human Development (NICHD) criteria. Adverse outcomes were defined as death before MRI or NICHD brain injury score > 1A.

RESULTS

 Infants in group 2 had lower Apgar scores at 5 minutes of age, severe acidemia, moderate to severe encephalopathy score, and earlier initiation of EEG monitoring than infants in group 1. Moderate to severe EEG background score was associated with presence of brain injury on MRI or death (p = 0.003), and this association remained significant even after adjustment for independent risk factors (odds ratio = 56.24 [95% confidence interval = 1.841-1718], p = 0.021).

CONCLUSION

 Phenobarbital therapy does not affect the ability of EEG to predict adverse outcome in infants with perinatal asphyxia during TH.

KEY POINTS

· EEG has a clinical utility for predicting outcome in neonates with hypoxia-ischemia.. · Phenobarbital therapy is commonly used in neonates, and may impact EEG background findings.. · In spite phenobarbital therapy, moderate to severe EEG background abnormalities in infants with perinatal asphyxia during TH remain an excellent predictor for poor outcome..

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.

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.

A Commentary on Electrographic Seizure Management and Clinical Outcomes in Critically Ill Children

Continuous EEG (cEEG) monitoring is the gold standard for detecting electrographic seizures in critically ill children and the current consensus-based guidelines recommend urgent cEEG to detect electrographic seizures that would otherwise be undetected. The detection of seizures usually leads to the use of antiseizure medications, even though current evidence that treatment leads to important improvements in outcomes is limited, raising the question of whether the current strategies need re-evaluation. There is emerging evidence indicating that the presence of electrographic seizures is not associated with unfavorable neurological outcome, and thus treatment is unlikely to alter the outcomes in these children. However, a high seizure burden and electrographic status epilepticus is associated with unfavorable outcome and the treatment of status epilepticus is currently warranted. Ultimately, outcomes are more likely a function of etiology than of a direct effect of the seizures themselves. We suggest re-examining our current consensus toward aggressive treatment to abolish all electrographic seizures and recommend a tailored approach where therapeutic interventions are indicated when seizure burden breaches above a critical threshold that may be associated with adverse outcomes. Future studies should explicitly evaluate whether there is a positive impact of treating electrographic seizures or electrographic status epilepticus in order to justify continuing current approaches.

Early predictors of neurodevelopment after perinatal arterial ischemic stroke: a systematic review and meta-analysis

BACKGROUND AND AIMS

Perinatal arterial ischemic stroke (PAIS) often has lifelong neurodevelopmental consequences. We aimed to review early predictors (<4 months of age) of long-term outcome.

METHODS

We carried out a systematic literature search (PubMed and Embase), and included articles describing term-born infants with PAIS that underwent a diagnostic procedure within four months of age, and had any reported outcome parameter ≥12 months of age. Two independent reviewers included studies and performed risk of bias analysis.

RESULTS

We included 41 articles reporting on 1395 infants, whereof 1255 (90%) infants underwent follow-up at a median of 4 years. A meta-analysis was performed for the development of cerebral palsy (n = 23 studies); the best predictor was the qualitative or quantitative assessment of the corticospinal tracts on MRI, followed by standardized motor assessments. For long-term cognitive functioning, bedside techniques including (a)EEG and NIRS might be valuable. Injury to the optic radiation on DTI correctly predicted visual field defects. No predictors could be identified for behavior, language, and post-neonatal epilepsy.

CONCLUSION

Corticospinal tract assessment on MRI and standardized motor assessments are best to predict cerebral palsy after PAIS. Future research should be focused on improving outcome prediction for non-motor outcomes.

IMPACT

We present a systematic review of early predictors for various long-term outcome categories after perinatal arterial ischemic stroke (PAIS), including a meta-analysis for the outcome unilateral spastic cerebral palsy. Corticospinal tract assessment on MRI and standardized motor assessments are best to predict cerebral palsy after PAIS, while bedside techniques such as (a)EEG and NIRS might improve cognitive outcome prediction. Future research should be focused on improving outcome prediction for non-motor outcomes.

Amplitude integrated EEG: how much it helps in prognostication in neonatal encephalopathy?

INTRODUCTION

Neonatal encephalopathy (NE) is associated with a high risk of adverse neurological outcomes. Several neurodiagnostic tests have been evaluated to predict the prognosis. Amplitude integrated Electroencephalogram (aEEG) is now being commonly used for bedside evaluation of cerebral function. There is limited data on the role of aEEG for prognostication in NE, from resource-limited settings.

OBJECTIVE

To evaluate the predictive ability of aEEG for abnormal neurological outcomes in neonatal encephalopathy or neonates with encephalopathy.

METHODS

Neonates above 35 weeks of gestation admitted to NICU in a tertiary care hospital with a diagnosis of encephalopathy were enrolled. Clinical characteristics severity of encephalopathy and seizures were recorded. Amplitude integrated recording was started at admission and continued till recovery of trace to normal or for 10 days. The primary outcome was death or abnormal neurological status at 3-6 months of age. The study was registered in the Clinical Trial Registry of India (CTRI/2013/05/003612).

RESULTS

The incidence of NE was 6% of total admission. Moderate and severe encephalopathy occurred in 58 and 39% of babies respectively. Hypoxic-ischemic encephalopathy was the most common cause. Clinical seizures occurred in 91% of cases. An abnormal aEEG trace was observed in 51 (76.1%) infants with NE. For adverse neurological outcomes at an age average of 4.5 months of age, aEEG had a sensitivity, specificity, NPV, and PPV of 100, 54.2, 100, and 77.5, respectively.

CONCLUSIONS

Clinical staging and aEEG has good predictive ability to detect an adverse neurological outcome. aEEG improves the ability to predict abnormal outcome in babies with moderate encephalopathy. Early recovery of aEEG abnormality correlates with better neurodevelopmental outcomes.KEY MESSAGESWhat's known: aEEG is a useful modality to assess neurodevelopmental outcomes however data from developing countries is lacking.What's new: aEEG monitoring in babies in neonatal encephalopathy may improve the prediction of abnormal neurological outcomes in babies with moderate encephalopathy.

Ganaxolone versus Phenobarbital for Neonatal Seizure Management

OBJECTIVE

Seizures are more common in the neonatal period than at any other stage of life. Phenobarbital is the first-line treatment for neonatal seizures and is at best effective in approximately 50% of babies, but may contribute to neuronal injury. Here, we assessed the efficacy of phenobarbital versus the synthetic neurosteroid, ganaxolone, to moderate seizure activity and neuropathology in neonatal lambs exposed to perinatal asphyxia.

METHODS

Asphyxia was induced via umbilical cord occlusion in term lambs at birth. Lambs were treated with ganaxolone (5mg/kg/bolus then 5mg/kg/day for 2 days) or phenobarbital (20mg/kg/bolus then 5mg/kg/day for 2 days) at 6 hours. Abnormal brain activity was classified as stereotypic evolving (SE) seizures, epileptiform discharges (EDs), and epileptiform transients (ETs) using continuous amplitude-integrated electroencephalographic recordings. At 48 hours, lambs were euthanized for brain pathology.

RESULTS

Asphyxia caused abnormal brain activity, including SE seizures that peaked at 18 to 20 hours, EDs, and ETs, and induced neuronal degeneration and neuroinflammation. Ganaxolone treatment was associated with an 86.4% reduction in the number of seizures compared to the asphyxia group. The total seizure duration in the asphyxia+ganaxolone group was less than the untreated asphyxia group. There was no difference in the number of SE seizures between the asphyxia and asphyxia+phenobarbital groups or duration of SE seizures. Ganaxolone treatment, but not phenobarbital, reduced neuronal degeneration within hippocampal CA1 and CA3 regions, and cortical neurons, and ganaxolone reduced neuroinflammation within the thalamus.

INTERPRETATION

Ganaxolone provided better seizure control than phenobarbital in this perinatal asphyxia model and was neuroprotective for the newborn brain, affording a new therapeutic opportunity for treatment of neonatal seizures. ANN NEUROL 2022;92:1066-1079.

EEG in neonatal seizures: where to look and what to see

INTRODUCTION

Neonatal seizures are frequent and carry a detrimental prognostic outlook. Diagnosis is based on EEG confirmation. Classification has recently changed.

AREAS COVERED

We consulted original papers, book chapters, atlases, and reviews to provide a narrative overview on EEG characteristics of neonatal seizures. We searched PubMed, without time restrictions (last visited: 31 May 2022). Additional papers were extracted from the references list of selected papers. We describe the typical neonatal ictal EEG discharges morphology, location, and propagation, together with age-dependent features. Etiology-dependent electroclinical features, when identifiable, are presented for both acute symptomatic neonatal seizures and neonatal-onset epilepsies and developmental/epileptic encephalopathies. The few ictal variables known to predict long-term outcome have been discussed.

EXPERT OPINION

Multimodal neuromonitoring in critically ill newborns, high-density EEG, and functional neuroimaging might increase our insight into the neurophysiological bases of seizures in newborns. Increasing availability of long-term monitoring with conventional video-EEG and automated detection methods will allow clinicians and researchers to gather an ever expanding bulk of clinical and neurophysiological data to enhance accuracy with deep phenotyping. The latest classification proposal represents an input for critically revising our diagnostic abilities with respect to seizure definition, duration, and semiology, possibly further promoting clinical research.

Neonatal seizures: stepping outside the comfort zone

Seizures are the most common neurological disorders in newborns. Managing neonatal seizures is challenging, especially for neurologists who are not neonatal specialists. Acute brain injury during ischemic insult is a key component of seizure occurrence, while genetic and metabolic disorders play less prevalent but more severe roles. The diagnosis of neonatal seizure is ambiguous, as the subjective differentiation between seizure and nonepileptic events is difficult; therefore, electrographic recording is the gold standard for diagnosis. The detection of electrographic seizures by neonatologists is currently facilitated by amplitude-integrated electroencephalography availability in many neonatal intensive care units. Although it is less sensitive than conventional electroencephalography, it is better to record all risky neonates to filter the abnormal events as early as possible to enable the initiation of dedicated therapy at proper dose and time and facilitate the initial response to antiepileptic drugs. This, in turn, helps maintain the balance between unnecessary drug use and their neurotoxic effects. Moreover, the early treatment of electrographic seizures plays a vital role in the suppression of subsequent abnormal brain electricity (status epilepticus) and shortening the hospital stay. An explicit understanding of seizure etiology and pathophysiology should direct attention to the proper prescription of short- and long-term antiepileptic medications to solve the challenging issue of whether neonatal seizures progress to postneonatal epilepsy and long-term cognitive deficits. This review addresses recent updates in different aspects of neonatal seizures, particularly electrographic discharge, including their definition, etiology, classification, diagnosis, management, and neurodevelopmental outcomes.

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.

Electroencephalogram background and head ultrasound together stratify seizure risk in neonates undergoing hypothermia

The benefits of continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU) are increasingly appreciated, though expanding indications for cEEG may strain resources. The current standard of care in babies with hypoxic-ischemic encephalopathy (HIE) undergoing therapeutic hypothermia (TH) includes cEEG monitoring throughout the entire TH and rewarming process (at least 72 h). Recent cEEG data demonstrate that most seizures occur within the first 24 h of monitoring. We hypothesized that abnormal head imaging and EEG background could stratify seizure risk in babies with HIE undergoing TH to identify candidates for early cEEG discontinuation. In this retrospective review of 126 neonates undergoing TH and cEEG, we identified seizures in 38 (30%) neonates, 33 (87%) of whom seized within the first 24 h of cEEG monitoring. EEG background was graded and demonstrated that 90% of neonates with seizures had a moderately/markedly abnormal background versus 33% of neonates who did not seize (p < 0.0001). Additionally, while head ultrasound (HUS) obtained before EEG did not stratify seizure risk alone, no neonates with both a normal/mildly abnormal EEG background and a normal HUS (0/25) experienced seizures in contrast to 60% (24/40) neonates with both an abnormal EEG background and an abnormal HUS (p < 0.0001). Our data suggest that neonates with abnormal EEG backgrounds and abnormal HUS should be monitored for seizures throughout TH and rewarming, while neonates with normal/mildly abnormal EEG backgrounds and normal HUS are at low risk of seizures after 24 h of monitoring, and thus would be candidates for early cEEG discontinuation.

Use of Continuous EEG Monitoring and Short-Term Outcomes in Critically Ill Children

This study aimed to compare short-term outcomes at pediatric intensive care unit (PICU) discharge in critically ill children with and without continuous electroencephalography (cEEG) monitoring. We retrospectively compared 234 patients who underwent cEEG with 2294 patients without cEEG. Propensity score matching was used to compare patients with seizures and status epilepticus between cEEG and historical cohorts. The EEG cohort had higher in-hospital mortality, worse Pediatric Cerebral Performance Category (PCPC) scores, and greater PCPC decline at discharge. In patients with status epilepticus, the PCPC decline was higher in the cEEG cohort. PCPC decline at PICU discharge was associated with cEEG monitoring in patients with status epilepticus.

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.

A method for AI assisted human interpretation of neonatal EEG

The study proposes a novel method to empower healthcare professionals to interact and leverage AI decision support in an intuitive manner using auditory senses. The method’s suitability is assessed through acoustic detection of the presence of neonatal seizures in electroencephalography (EEG). Neurophysiologists use EEG recordings to identify seizures visually. However, neurophysiological expertise is expensive and not available 24/7, even in tertiary hospitals. Other neonatal and pediatric medical professionals (nurses, doctors, etc.) can make erroneous interpretations of highly complex EEG signals. While artificial intelligence (AI) has been widely used to provide objective decision support for EEG analysis, AI decisions are not always explainable. This work developed a solution to combine AI algorithms with a human-centric intuitive EEG interpretation method. Specifically, EEG is converted to sound using an AI-driven attention mechanism. The perceptual characteristics of seizure events can be heard using this method, and an hour of EEG can be analysed in five seconds. A survey that has been conducted among targeted end-users on a publicly available dataset has demonstrated that not only does it drastically reduce the burden of reviewing the EEG data, but also the obtained accuracy is on par with experienced neurophysiologists trained to interpret neonatal EEG. It is also shown that the proposed communion of a medical professional and AI outperforms AI alone by empowering the human with little or no experience to leverage AI attention mechanisms to enhance the perceptual characteristics of seizure events.

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.

Efficacy of Levetiracetam and Phenobarbital as First-Line Treatment for Neonatal Seizures

High neonatal seizure burden is associated with worsened neurodevelopmental outcomes. We compared the efficacy of initial treatment with levetiracetam vs phenobarbital for maintaining low seizure burden in a retrospective cohort of 25 neonates monitored with video electroencephalography (EEG). Video EEG tracing were reviewed and paired with medication bolus times to determine seizure burden after treatment. Initial cumulative dose of phenobarbital was 20 mg/kg in all but 1 case; initial cumulative dose of levetiracetam ranged from 50 to 100 mg/kg. Eleven of 17 (65%) patients sustained seizure burden <10% following initial treatment with levetiracetam, compared with 5 of 8 (63%) with phenobarbital. Thirteen (76%) patients treated with levetiracetam had sustained seizure burden <20% compared with 6 (75%) treated with phenobarbital. The phenobarbital group showed a larger absolute reduction in average seizure burden in the hour before and after treatment (-24.3  vs -14.2 minutes/h). Six of 17 (35%) patients treated with levetiracetam remained seizure free after initial treatment, compared with 2 of 8 (25%) patients treated with phenobarbital. Initial treatment with levetiracetam was associated with shorter average time to seizure freedom (15 vs 21 hours). None of these results were statistically significant. Cumulative doses of levetiracetam 100 mg/kg were well tolerated and associated with substantial decrease in seizure burden in several cases. Levetiracetam remains a promising first-line treatment for neonatal seizures; additional randomized controlled trials evaluating the effects of high-dose levetiracetam on seizure burden and long-term outcomes are warranted.

Neonatal Seizures-Perspective in Low-and Middle-Income Countries

Neonatal seizures are the commonest neurological emergency and are associated with poor neurodevelopmental outcome. While they are generally difficult to diagnose and treat, they pose a significant clinical challenge for physicians in low- and middle-income countries (LMIC). They are mostly provoked seizures caused by an acute brain insult such as hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the central nervous system, or acute metabolic disturbances. Early onset epilepsy syndromes are less common. Clinical diagnosis of seizures in the neonatal period are frequently inaccurate, as clinical manifestations are difficult to distinguish from nonseizure behavior. Additionally, a high proportion of seizures are electrographic-only without any clinical manifestations, making diagnosis with EEG or aEEG a necessity. Only focal clonic and focal tonic seizures can be diagnosed clinically with adequate diagnostic certainty. Prompt diagnosis and timely treatment are important, with evidence suggesting that early treatment improves the response to antiseizure medication. The vast majority of published studies are from high-income countries, making extrapolation to LMIC impossible, thus highlighting the urgent need for a better understanding of the etiologies, comorbidities, and drug trials evaluating safety and efficacy in LMIC. In this review paper, the authors present the latest data on etiology, diagnosis, classification, and guidelines for the management of neonates with the emphasis on low-resource settings.

Case Report: Congenital disseminated tuberculosis neonate born to tuberculosis- COVID-19 mother

We report a case of a 26-day-old male neonate with high suggestive of congenital disseminated tuberculosis (TB) [tuberculous meningitis (TBM), pulmonary TB, and ocular TB] at term, low birth weight born cesarean section from a confirmed COVID-19 and pulmonary TB mother who hospitalized in the isolation room and never seen her son for three weeks. The baby had a fever for two weeks after birth and a history of seizures. A nasopharyngeal swab for RT-PCR SARS-CoV-2 yielded a negative result. He was initially diagnosed as having a sepsis-like syndrome and then hospitalized. Chest x-ray revealed bilateral infiltrate, cerebrospinal fluid analysis (CSF) showed clear, cell count was 9 with dominant mononuclear cell, and gastric lavages did not yield acid-fast bacilli. X-pert MTB/RIF from gastric lavage specimen detected Mycobacterium tuberculosis rifampicin sensitive. Anti-tuberculosis drugs for TBM were started. Abdominal sonography identified multiple hypoechoic nodules in the liver and spleen. Neuroimaging studies did not identify hydrocephalus, meningeal enhancement, infarct, or tuberculoma. A Video-EEG examination showed electrical seizure after initiation of phenobarbital. Video-EEG evaluation showed no epileptiform discharge. Upon follow-up, he showed slightly delayed motor development, pan-uveitis, retinal detachment, and cataracts. We assumed that ocular TB resulted from a paradoxical reaction following TB treatment. Retinal detachment was improved and lens replacement was done.

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.

Prognostic Risk Factors for Severe Outcome in the Acute Phase of Neonatal Hypoxic-Ischemic Encephalopathy: A Prospective Cohort Study

In the first days after birth, a major focus of research is to identify infants with hypoxic-ischemic encephalopathy at higher risk of death or severe neurological impairment, despite therapeutic hypothermia (TH). This is especially crucial to consider redirection of care, according to neonatal outcome severity. We aimed to seek associations between some neonatal routine parameters, usually recorded in Neonatal Intensive Care Units, and the development of severe outcomes. All consecutive patients prospectively recruited for TH for perinatal asphyxia, born between February 2009 and July 2016, were eligible for this study. Severe outcome was defined as death or major neurological sequelae at one year of age. Among all eligible neonates, the final analysis included 83 patients. Severe outcome was significantly associated with pH and base excess measured in the first hour of life, mode of delivery, Apgar score, Sarnat and Sarnat score, electroencephalogram-confirmed neonatal epileptic seizures, and antiepileptic therapy. Studying univariate analysis by raw relative risk (RR) and 95% confidence intervals (CI), severe outcome was significantly associated with pH (p = 0.011), Apgar score (p = 0.003), Sarnat score (p < 0.001), and Caesarian section (p = 0.015). Conclusions. In addition to clinical examination, we suggest a clinical-electroencephalographic protocol useful to identify neonates at high neurological risk, available before rewarming from TH.

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.

Management of seizures in neonates with neonatal encephalopathy treated with hypothermia

Neonatal encephalopathy (NE) is the most common etiology of acute neonatal seizures - about half of neonates treated with therapeutic hypothermia for NE have EEG-confirmed seizures. These seizures are best identified with continuous EEG monitoring, as clinical diagnosis leads to under-diagnosis of subclinical seizures and over-treatment of events that are not seizures. High seizure burden, especially status epilepticus, is thought to augment brain injury. Treatment, therefore, is aimed at minimizing seizure burden. Phenobarbital remains the mainstay of treatment, as it is more effective than levetiracetam and easier to administer than fosphenytoin. Emerging evidence suggests that, for many neonates, it is safe to discontinue the phenobarbital after acute seizures resolve and prior to hospital discharge.

Early-life epilepsy after acute symptomatic neonatal seizures: A prospective multicenter study

OBJECTIVE

We aimed to evaluate early-life epilepsy incidence, seizure types, severity, risk factors, and treatments among survivors of acute neonatal seizures.

METHODS

Neonates with acute symptomatic seizures born 7/2015-3/2018 were prospectively enrolled at nine Neonatal Seizure Registry sites. One-hour EEG was recorded at age three months. Post-neonatal epilepsy and functional development (Warner Initial Developmental Evaluation of Adaptive and Functional Skills - WIDEA-FS) were assessed. Cox regression was used to assess epilepsy-free survival.

RESULTS

Among 282 infants, 37 (13%) had post-neonatal epilepsy by 24-months [median age of onset 7-months (IQR 3-14)]. Among those with post-neonatal epilepsy, 13/37 (35%) had infantile spasms and 12/37 (32%) had drug-resistant epilepsy. Most children with post-neonatal epilepsy had abnormal neurodevelopment at 24-months (WIDEA-FS >2SD below normal population mean for 81% of children with epilepsy vs 27% without epilepsy, RR 7.9, 95% CI 3.6-17.3). Infants with severely abnormal neonatal EEG background patterns were more likely to develop epilepsy than those with mild/moderate abnormalities (HR 3.7, 95% CI 1.9-5.9). Neonatal EEG with ≥3 days of seizures also predicted hazard of epilepsy (HR 2.9, 95% CI 1.4-5.9). In an adjusted model, days of neonatal EEG-confirmed seizures (HR 1.4 per day, 95% CI 1.2-1.6) and abnormal discharge examination (HR 3.9, 95% CI 1.9-7.8) were independently associated with time to epilepsy onset. Abnormal (vs. normal) three-month EEG was not associated with epilepsy.

SIGNIFICANCE

In this multicenter study, only 13% of infants with acute symptomatic neonatal seizures developed post-neonatal epilepsy by age 24-months. However, there was a high risk of severe neurodevelopmental impairment and drug-resistant seizures among children with post-neonatal epilepsy. Days of EEG-confirmed neonatal seizures was a potentially modifiable epilepsy risk factor. An EEG at three months was not clinically useful for predicting epilepsy. These practice changing findings have implications for family counseling, clinical follow-up planning, and future research to prevent post-neonatal epilepsy.

Carbonic anhydrase inhibitors suppress seizures in a rat model of birth asphyxia

OBJECTIVE

Seizures are common in neonates recovering from birth asphyxia but there is general consensus that current pharmacotherapy is suboptimal and that novel antiseizure drugs are needed. We recently showed in a rat model of birth asphyxia that seizures are triggered by the post-asphyxia recovery of brain pH. Here our aim was to investigate whether carbonic anhydrase inhibitors (CAIs), which induce systemic acidosis, block the post-asphyxia seizures.

METHODS

The CAIs acetazolamide (AZA), benzolamide (BZA), and ethoxzolamide (EZA) were administered intraperitoneally or intravenously to 11-day-old rats exposed to intermittent asphyxia (30 min; three 7+3 min cycles of 9% and 5% O₂ at 20% CO₂ ). Electrode measurements of intracortical pH, Po₂ , and local field potentials (LFPs) were made under urethane anesthesia. Convulsive seizures and blood acid-base parameters were examined in freely behaving animals.

RESULTS

The three CAIs decreased brain pH by 0.14-0.17 pH units and suppressed electrographic post-asphyxia seizures. AZA, BZA, and EZA differ greatly in their lipid solubility (EZA > AZA > BZA) and pharmacokinetics. However, there were only minor differences in the delay (range 0.8-3.7 min) from intraperitoneal application to their action on brain pH. The CAIs induced a modest post-asphyxia elevation of brain Po₂ that had no effect on LFP activity. AZA was tested in freely behaving rats, in which it induced a respiratory acidosis and decreased the incidence of convulsive seizures from 9 of 20 to 2 of 17 animals.

SIGNIFICANCE

AZA, BZA, and EZA effectively block post-asphyxia seizures. Despite the differences in their pharmacokinetics, they had similar effects on brain pH, which indicates that their antiseizure mode of action was based on respiratory (hypercapnic) acidosis resulting from inhibition of blood-borne and extracellular vascular carbonic anhydrases. AZA has been used for several indications in neonates, suggesting that it can be safely repurposed for the treatment of neonatal seizures as an add-on to the current treatment regimen.

Induction of Tertiary Phase Epileptiform Discharges after Postasphyxial Infusion of a Toll-Like Receptor 7 Agonist in Preterm Fetal Sheep

Background: Toll-like receptor (TLR) agonists are key immunomodulatory factors that can markedly ameliorate or exacerbate hypoxic–ischemic brain injury. We recently demonstrated that central infusion of the TLR7 agonist Gardiquimod (GDQ) following asphyxia was highly neuroprotective after 3 days but not 7 days of recovery. We hypothesize that this apparent transient neuroprotection is associated with modulation of seizure-genic processes and hemodynamic control. Methods: Fetuses received sham asphyxia or asphyxia induced by umbilical cord occlusion (20.9 ± 0.5 min) and were monitored continuously for 7 days. GDQ 3.34 mg or vehicle were infused intracerebroventricularly from 1 to 4 h after asphyxia. Results: GDQ infusion was associated with sustained moderate hypertension that resolved after 72 h recovery. Electrophysiologically, GDQ infusion was associated with reduced number and burden of postasphyxial seizures in the first 18 h of recovery (p < 0.05). Subsequently, GDQ was associated with induction of slow rhythmic epileptiform discharges (EDs) from 72 to 96 h of recovery (p < 0.05 vs asphyxia + vehicle). The total burden of EDs was associated with reduced numbers of neurons in the caudate nucleus (r² = 0.61, p < 0.05) and CA1/2 hippocampal region (r² = 0.66, p < 0.05). Conclusion: These data demonstrate that TLR7 activation by GDQ modulated blood pressure and suppressed seizures in the early phase of postasphyxial recovery, with subsequent prolonged induction of epileptiform activity. Speculatively, this may reflect delayed loss of early protection or contribute to differential neuronal survival in subcortical regions.

Clinical manifestations of neonatal seizures

Neonatal seizures present a unique diagnostic challenge with clinical manifestations often subtle or absent to the bedside observer. Seizures can be overdiagnosed in newborns with unusual paroxysmal movements and underdiagnosed in newborns without clinical signs of seizures. Electroclinical "uncoupling" also adds to the diagnostic challenge. Reliable diagnosis requires additional tools; continuous electroencephalogram (EEG) monitoring is the gold standard for diagnosis of neonatal seizures. Certain high-risk neonatal populations with known brain injury, such as stroke or hypoxic-ischemic encephalopathy, are most likely to benefit from continuous EEG. Studies have shown that risk stratification for continuous EEG has positive impact on care, including rapid and accurate diagnosis and treatment of neonatal seizures, which leads to reduced use of antiseizure medicines and length of hospital stay. This review describes common clinical manifestations of neonatal seizures, and clinical situations in which EEG monitoring to screen for seizures should be considered.

Risk Factors for Mortality among Newborns with Neonatal Seizures

OBJECTIVE

The aim of the study is to examine the incidence and risk factors for death among neonates who developed neonatal seizures (NS) in an ethnically distinctive community with high consanguinity rate in Israel.

METHODS

Retrospective study was conducted at a single institution on data between January 2001 and January 2016. All neonates diagnosed with NS developed up to age 28 days were included. Mortality was defined as death within the first year of life.

RESULTS

Of all 69,460 neonates born during the study period, 118 (1.7 per 1,000 live births) developed NS; 35 (29.7%) died within the first year while 83 (70.3%) survived. The leading causes of death were developmental brain malformation (31.4%), genetic/metabolic (20%), hypoxic ischemic encephalopathy (20%), intracranial hemorrhage (11.4%) and infections (11.4%). Any consanguinity between the parents was found in 18 and 14.6% among the survivors and deceased groups, respectively (p = 0.24). Developmental brain malformations that lead to death were present in 3.6 and 31.4% in the survivors and deceased groups, respectively (p = 0.001; relative risk 8.70; 95% confidence interval 2.58-29.27). Stepwise backward logistic regression analysis revealed that developmental brain malformations (p < 0.0001), use of more than one antiepileptic medication (p = 0.006), and multiorgan failure (p = 0.004) were significant risk factors that predicted death.

CONCLUSION

The results of the current study show that developmental brain malformations that cause NS were the leading risk factor for death.

Does the first hour of continuous electroencephalography predict neonatal seizures?

OBJECTIVE

Prolonged continuous video-electroencephalography (cEEG) is recommended for neonates at risk of seizures. The cost and expertise required to provide a real-time response to detected seizures often limits its utility. We hypothesised that the first hour of cEEG could predict subsequent seizures.

DESIGN AND SETTING

Retrospective multicentre diagnostic accuracy study.

PATIENTS

266 term neonates at risk of seizure or with suspected seizures.

INTERVENTION

The first hour of cEEG was graded by expert and novice interpreters as normal, mildly, moderately or severely abnormal; seizures were identified.

MAIN OUTCOME MEASURES

Association between abnormalities in the first hour of cEEG and the presence of seizures during total cEEG monitoring.

RESULTS

50/98 (51%) of neonates who developed seizures had their first seizure in the first hour of cEEG monitoring. The 'time-to-event' risk of seizure from 0 to 96 hours was 0.38 (95% CI 0.32 to 0.44) while the risk in the first hour was 0.19 (95% CI 0.15 to 0.24). cEEG background was normal in 48% of neonates, mildly abnormal in 30%, moderately abnormal in 13% and severely abnormal in 9%. Inter-rater agreement for determination of background was very good (weighted kappa=0.81, 95% CI 0.72 to 0.91). When neonates with seizures during the first hour were excluded, an abnormal background resulted in 2.4 times increased risk of seizures during the subsequent monitoring period (95% CI 1.3 to 4.4, p<0.003) while a severely abnormal background resulted in a sevenfold increased risk (95% CI 3.4 to 14.3, p<0.0001).

CONCLUSIONS

The first hour of cEEG in at-risk neonates is useful in identifying and predicting whether seizures occur during cEEG monitoring up to 96 hours. This finding enables identification of high-risk neonates who require closer observation.

The ILAE classification of seizures and the epilepsies: Modification for seizures in the neonate. Position paper by the ILAE Task Force on Neonatal Seizures

Seizures are the most common neurological emergency in the neonatal period and in contrast to those in infancy and childhood, are often provoked seizures with an acute cause and may be electrographic-only. Hence, neonatal seizures may not fit easily into classification schemes for seizures and epilepsies primarily developed for older children and adults. A Neonatal Seizures Task Force was established by the International League Against Epilepsy (ILAE) to develop a modification of the 2017 ILAE Classification of Seizures and Epilepsies, relevant to neonates. The neonatal classification framework emphasizes the role of electroencephalography (EEG) in the diagnosis of seizures in the neonate and includes a classification of seizure types relevant to this age group. The seizure type is determined by the predominant clinical feature. Many neonatal seizures are electrographic-only with no evident clinical features; therefore, these are included in the proposed classification. Clinical events without an EEG correlate are not included. Because seizures in the neonatal period have been shown to have a focal onset, a division into focal and generalized is unnecessary. Seizures can have a motor (automatisms, clonic, epileptic spasms, myoclonic, tonic), non-motor (autonomic, behavior arrest), or sequential presentation. The classification allows the user to choose the level of detail when classifying seizures in this age group.

Efficacy and Safety of Phenobarbitone as First-Line Treatment for Neonatal Seizure: A Systematic Review and Meta-Analysis

BACKGROUND AND OBJECTIVE

Phenobarbitone is used as a first-line drug for neonatal seizures. However, its poor short- and long-term safety profile is concerning. We aim to systematically synthesize the data on the efficacy and safety of phenobarbitone as a first-line agent and compare it against other anti-epileptic drugs (AEDs) in neonates.

METHODS

Using keywords related to the study population (neonatal seizure) and intervention (phenobarbitone), we searched CENTRAL, Embase, PubMed and Web of Science until 15 December 2020. Randomized controlled trials (RCTs) comparing phenobarbitone with any other AED as first-line therapy for seizure control in the neonates were considered eligible. The random-effect meta-analysis was done using RevMan 5.3 software.

RESULTS

We screened through 443 records and identified nine eligible studies (719 participants). Five RCTs comparing phenobarbitone with levetiracetam did not find any difference in seizure control with the first dose [risk ratio (RR) 1.43, 95% CI 0.79-2.57] or adverse effects (RR 4.66; 95% CI 0.33-65.83). Two trials comparing phenobarbitone and phenytoin also did not find any difference in seizure control with the first dose (RR 2.09; 95% CI 0.31-14.03) and other outcomes. Only one RCT compared phenobarbitone and lorazepam and found lorazepam to be more efficacious in seizure control with the first dose (RR 0.71; 95% CI 0.53-0.94). Three trials compared neurodevelopmental outcomes, in which levetiracetam was better in two, whereas one did not find any difference.

CONCLUSION

Phenobarbitone is at least as efficacious and safe as other drugs like phenytoin and levetiracetam. The data over the long-term neurodevelopmental outcome are lacking. The existing evidence is insufficient to recommend other drugs over phenobarbitone.

Efficacy of Fosphenytoin as First-Line Antiseizure Medication for Neonatal Seizures Compared to Phenobarbital

Currently used treatment protocols for neonatal seizures vary among centers with limited evidence to support the choice of a given antiseizure medication. Because of concerns about the potential negative impact of phenobarbital on long-term neurodevelopment outcomes, our unit transitioned to fosphenytoin as the first-line antiseizure medication. A retrospective observational cohort study was conducted to compare the acute and long-term outcomes of fosphenytoin and phenobarbital as first-line antiseizure medication for neonatal seizure treatment. The 2 study groups had similar baseline characteristics for neonatal variables as well as maternal antenatal complications. We did not find any differences in the acute outcomes between the 2 groups. However, significantly fewer infants in the fosphenytoin group had moderate-to-severe neurodevelopmental delay at the 18- and 24-month assessments. In conclusion, although both medications were equally efficacious for acute neonatal seizure control, fosphenytoin had the potential for significantly better neurodevelopmental outcomes at 18-24 months of age.

Current and Future Uses of Continuous EEG in the NICU

Continuous EEG (cEEG) is a fundamental neurodiagnostic tool in the care of critically ill neonates and is increasingly recommended. cEEG enhances prognostication via assessment of the background brain activity, plays a role in predicting which neonates are at risk for seizures when combined with clinical factors, and allows for accurate diagnosis and management of neonatal seizures. Continuous EEG is the gold standard method for diagnosis of neonatal seizures and should be used for detection of seizures in high-risk clinical conditions, differential diagnosis of paroxysmal events, and assessment of response to treatment. High costs associated with cEEG are a limiting factor in its widespread implementation. Centralized remote cEEG interpretation, automated seizure detection, and pre-natal EEG are potential future applications of this neurodiagnostic tool.

Sex specific correlation between GABAergic disruption in the dorsal hippocampus and flurothyl seizure susceptibility after neonatal hypoxic-ischemic brain injury

Since neonatal hypoxia-ischemia (HI) disrupts the hippocampal (Hp) GABAergic network in the mouse and Hp injury in this model correlates with flurothyl seizure susceptibility only in male mice, we hypothesized that GABAergic disruption correlates with flurothyl seizure susceptibility in a sex-specific manner. C57BL6 mice were exposed to HI (Vannucci model) versus sham procedures at P10, randomized to normothermia (NT) or therapeutic hypothermia (TH), and subsequently underwent flurothyl seizure testing at P18. Only in male mice, Hp atrophy correlated with seizure susceptibility. The number of Hp parvalbumin positive interneurons (PV⁺INs) decreased after HI in both sexes, but TH attenuated this deficit only in females. In males only, seizure susceptibility directly correlated with the number of PV⁺INs, but not somatostatin or calretinin expressing INs. Hp GABA_B receptor subunit levels were decreased after HI, but unrelated to later seizure susceptibility. In contrast, Hp GABA_A receptor α1 subunit (GABA_ARα1) levels were increased after HI. Adjusting the number of PV⁺ INs for their GABA_ARα1 expression strengthened the correlation with seizure susceptibility in male mice. Thus, we identified a novel Hp sex-specific GABA-mediated mechanism of compensation after HI that correlates with flurothyl seizure susceptibility warranting further study to better understand potential clinical translation.

Acute symptomatic neonatal seizures, brain injury, and long-term outcome: The role of neuroprotective strategies

INTRODUCTION

Neonatal seizures are frequent but underdiagnosed manifestations of acute brain dysfunction and an important contributor to unfavorable outcomes. Etiology and severity of brain injury are the single strongest outcome determinants.

AREAS COVERED

The authors will discuss the prognostic role of acute symptomatic seizures versus brain injury and the main neuroprotective and neurorestorative strategies for full-term and preterm infants.

EXPERT OPINION

Prolonged acute symptomatic seizures likely contribute to long-term outcomes by independently adding further brain injury to initial insults. Correct timing and dosing of therapeutic interventions, depending on etiology and gestational ages, need careful evaluation. Although promising strategies are under study, the only standard of care is whole-body therapeutic hypothermia in full-term newborns with hypoxic-ischemic encephalopathy.

Corpus Callosotomy for Refractory Epilepsy in Aicardi Syndrome: Case Report and Focused Review of the Literature

BACKGROUND

Aicardi syndrome is a severe neurodevelopmental disorder that occurs primarily in females and is characterized by seizures, agenesis of the corpus callosum, and chorioretinal lacunae, which occur together in the majority of affected individuals. Seizures begin in infancy and tend to progress in intensity and are often refractory to standard multimodal medication treatments.

CASE DESCRIPTION

We present here a unique case of a 12-year-old girl with partial agenesis of the corpus callosum who underwent a corpus callosotomy for treatment of medically refractory epilepsy. In so doing, we also review the literature with regard to the neurosurgical management of these unique patients.

CONCLUSIONS

For the subset of children who present with partial, rather than complete, agenesis of the corpus callosum, corpus callosotomy should be considered as a treatment option to reduce seizure burden.

A Trial of Real-Time Electrographic Seizure Detection by Neuro-ICU Nurses Using a Panel of Quantitative EEG Trends

BACKGROUND

Non-convulsive seizures (NCS) are a common occurrence in the neurologic intensive care unit (Neuro-ICU) and are associated with worse outcomes. Continuous electroencephalogram (cEEG) monitoring is necessary for the detection of NCS; however, delays in interpretation are a barrier to early treatment. Quantitative EEG (qEEG) calculates a time-compressed simplified visual display from raw EEG data. This study aims to evaluate the performance of Neuro-ICU nurses utilizing bedside, real-time qEEG interpretation for detecting recurrent NCS.

METHODS

This is a prospective, single-institution study of patients admitted to the Duke Neuro-ICU between 2016 and 2018 who had NCS identified on traditional cEEG review. The accuracy of recurrent seizure detection on hourly qEEG review by bedside Neuro-ICU nurses was compared to the gold standard of cEEG interpretation by two board-certified neurophysiologists. The nurses first received brief qEEG training, individualized for their specific patient. The bedside qEEG display consisted of rhythmicity spectrogram (left and right hemispheres) and amplitude-integrated EEG (left and right hemispheres) in 1-h epochs.

RESULTS

Twenty patients were included and 174 1-h qEEG blocks were analyzed. Forty-seven blocks contained seizures (27%). The sensitivity was 85.1% (95% CI 71.1-93.1%), and the specificity was 89.8% (82.8-94.2%) for the detection of seizures for each 1-h block when compared to interpretation of conventional cEEG by two neurophysiologists. The false positive rate was 0.1/h. Hemispheric seizures (> 4 unilateral EEG electrodes) were more likely to be correctly identified by nurses on qEEG than focal seizures (≤ 4 unilateral electrodes) (p = 0.03).

CONCLUSIONS

After tailored training sessions, Neuro-ICU nurses demonstrated a good sensitivity for the interpretation of bedside real-time qEEG for the detection of recurrent NCS with a low false positive rate. qEEG is a promising tool that may be used by non-neurophysiologists and may lead to earlier detection of NCS.

Continuous Electroencephalography Monitoring in Critically Ill Infants and Children

Continuous video electroencephalography (CEEG) monitoring of critically ill infants and children has expanded rapidly in recent years. Indications for CEEG include evaluation of patients with altered mental status, characterization of paroxysmal events, and detection of electrographic seizures, including monitoring of patients with limited neurological examination or conditions that put them at high risk for electrographic seizures (e.g., cardiac arrest or extracorporeal membrane oxygenation cannulation). Depending on the inclusion criteria and clinical characteristics of the population studied, the percentage of pediatric patients with electrographic seizures varies from 7% to 46% and with electrographic status epilepticus from 1% to 23%. There is also evidence that epileptiform and background CEEG patterns may provide important information about prognosis in certain clinical populations. Quantitative EEG techniques are emerging as a tool to enhance the value of CEEG to provide real-time bedside data for management and prognosis. Continued research is needed to understand the clinical value of seizure detection and identification of other CEEG patterns on the outcomes of critically ill infants and children.

Levetiracetam Versus Phenobarbital for Neonatal Seizures: A Randomized Controlled Trial

BACKGROUND AND OBJECTIVES

There are no US Food and Drug Administration-approved therapies for neonatal seizures. Phenobarbital and phenytoin frequently fail to control seizures. There are concerns about the safety of seizure medications in the developing brain. Levetiracetam has proven efficacy and an excellent safety profile in older patients; therefore, there is great interest in its use in neonates. However, randomized studies have not been performed. Our objectives were to study the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment of neonatal seizures.

METHODS

The study was a multicenter, randomized, blinded, controlled, phase IIb trial investigating the efficacy and safety of levetiracetam compared with phenobarbital as a first-line treatment for neonatal seizures of any cause. The primary outcome measure was complete seizure freedom for 24 hours, assessed by independent review of the EEGs by 2 neurophysiologists.

RESULTS

Eighty percent of patients (24 of 30) randomly assigned to phenobarbital remained seizure free for 24 hours, compared with 28% of patients (15 of 53) randomly assigned to levetiracetam (P < .001; relative risk 0.35 [95% confidence interval: 0.22-0.56]; modified intention-to-treat population). A 7.5% improvement in efficacy was achieved with a dose escalation of levetiracetam from 40 to 60 mg/kg. More adverse effects were seen in subjects randomly assigned to phenobarbital (not statistically significant).

CONCLUSIONS

In this phase IIb study, phenobarbital was more effective than levetiracetam for the treatment of neonatal seizures. Higher rates of adverse effects were seen with phenobarbital treatment. Higher-dose studies of levetiracetam are warranted, and definitive studies with long-term outcome measures are needed.