Outcome following neonatal seizures

Infant sleep spindle measures from EEG improve prediction of cerebral palsy

OBJECTIVE

Early identification of infants at risk of cerebral palsy (CP) enables interventions to optimize outcomes. Central sleep spindles reflect thalamocortical sensorimotor circuit function. We hypothesized that abnormal infant central spindle activity would predict later contralateral CP.

METHODS

We trained and validated an automated detector to measure spindle rate, duration, and percentage from central electroencephalogram (EEG) channels in high-risk infants (n = 35) and age-matched controls (n = 42). Neonatal magnetic resonance imaging (MRI) findings, infant motor exam, and CP outcomes were obtained from chart review. Using univariable and multivariable logistic regression models, we examined whether spindle activity, MRI abnormalities, and/or motor exam predicted future contralateral CP.

RESULTS

The detector had excellent performance (F1 = 0.50). Spindle rate (p = 0.005, p = 0.0004), duration (p < 0.001, p < 0.001), and percentage (p < 0.001, p < 0.001) were decreased in hemispheres corresponding to future CP compared to those without. In this cohort, PLIC abnormality (p = 0.004) and any MRI abnormality (p = 0.004) also predicted subsequent CP. After controlling for MRI findings, spindle features remained significant predictors and improved model fit (p < 0.001, all tests). Using both spindle duration and MRI findings had highest accuracy to classify hemispheres corresponding to future CP (F1 = 0.98, AUC 0.999).

CONCLUSION

Decreased central spindle activity improves the prediction of future CP in high-risk infants beyond early MRI or clinical exam alone.

SIGNIFICANCE

Decreased central spindle activity provides an early biomarker for CP.

Treating Seizures and Improving Newborn Outcomes for Infants with Hypoxic-Ischemic Encephalopathy

Hypoxic-ischemic encephalopathy is the most common cause of neonatal seizures. Continuous electroencephalographic monitoring is recommended given high rates of subclinical seizures. Prompt diagnosis and treatment of seizures may improve neurodevelopmental outcomes. International League Against Epilepsy guidelines indicate that (1) phenobarbital remains the first-line treatment of neonatal seizures and (2) early discontinuation of antiseizure medications following resolution of acute provoked seizures, and prior to discharge home, is recommended. Long-term follow-up of these infants is necessary to screen for postneonatal epilepsy and support neurodevelopment.

Clinical Experience With Lacosamide as an Adjunct Treatment for Neonatal Seizures: A Retrospective Single-Center Study

BACKGROUND

Lacosamide (LCM) is a third-generation antiseizure medication (ASM) currently approved for the treatment of focal seizures in children aged greater than one month. There are limited data on its efficacy in the neonatal age group. We describe our experience with LCM as an adjunct ASM for the treatment of neonatal seizures.

METHODS

A retrospective chart review over a five-year period (2018 to 2022) was conducted at Le Bonheur Children's Hospital to identify neonates with electroencephalography (EEG)-proven seizures who were treated with LCM. Data were collected on electroclinical seizure characteristics, underlying etiology, ASMs, treatment response, and any adverse effects.

RESULTS

A total of 15 neonates with EEG-confirmed seizures who were treated with LCM were included. Ten neonates achieved seizure cessation after LCM was added to their ASM regimen consisting of phenobarbital, levetiracetam, or both. No new treatment-related adverse effects were noted.

CONCLUSIONS

LCM is effective as an adjunct treatment for neonatal seizures. Randomized controlled studies are needed to establish its effectiveness and adequate dosing regimen in this population.

Assessment of extremely premature lambs supported by the Extrauterine Environment for Neonatal Development (EXTEND)

BACKGROUND

Our team has previously reported physiologic support by the EXTra-uterine Environment for Neonatal Development (EXTEND) of 105 to 117 days gestational age (GA) lambs for up to 28 days with normal organ maturation. However, the fetal lamb brain matures more rapidly, requiring the study of 90-105 day GA fetal lambs to assess more neurodevelopmentally equivalent lambs to the 23-25 week GA extreme premature infant.

METHODS

Extremely preterm lambs (90-95 days of GA) were delivered by C-section and supported by EXTEND. Estimated circuit flows were maintained at around 325 ml/kg/min. After support on EXTEND, MRI and histopathologic analysis were performed and compared to 105-112 days GA control lambs.

RESULTS

The extremely preterm group includes 10 animals with a mean GA of 91.6 days, a mean weight at cannulation of 0.98 kg and a mean length of stay on EXTEND of 13.5 days (10-21 days). Hemodynamics and oxygenation showed stable parameters. Animals showed growth and physiologic cardiac function. MRI volumetric and diffusion analysis was comparable to controls. Histologic brain analysis revealed no difference between study groups.

CONCLUSION

EXTEND appears to support brain and cardiac development in an earlier gestation, less mature, lamb model.

IMPACT

Prolonged (up to 21 days) physiological support of extremely preterm lambs of closer neurodevelopmental equivalence to the 24-28 gestational week human was achieved using the EXTEND system. EXTEND treatment supported brain growth and development in extremely preterm fetal lambs and was not associated with intraventricular hemorrhage or white matter injury. Daily echocardiography demonstrated physiologic heart function, absence of cardiac afterload, and normal developmental increase in cardiac chamber dimensions. This study demonstrates hemodynamic and metabolic support by the EXTEND system in the extremely preterm ovine model.

Retrospective Multicenter Cohort Study on Safety and Electroencephalographic Response to Lacosamide for Neonatal Seizures

BACKGROUND

There is growing evidence supporting the safety and effectiveness of lacosamide in older children. However, minimal data are available for neonates. We aimed to determine the incidence of adverse events associated with lacosamide use and explore the electroencephalographic seizure response to lacosamide in neonates.

METHODS

A retrospective cohort study was conducted using data from seven pediatric hospitals from January 2009 to February 2020. For safety outcomes, neonates were followed for ≤30 days from index date. Electroencephalographic response of lacosamide was evaluated based on electroencephalographic reports for ≤3 days.

RESULTS

Among 47 neonates, 98% received the first lacosamide dose in the intensive care units. During the median follow-up of 12 days, 19% of neonates died, and the crude incidence rate per 1000 patient-days (95% confidence interval) of the adverse events by diagnostic categories ranged from 2.8 (0.3, 10.2) for blood or lymphatic system disorders and nervous system disorders to 10.5 (4.2, 21.6) for cardiac disorders. Electroencephalographic seizures were observed in 31 of 34 patients with available electroencephalographic data on the index date. There was seizure improvement in 29% of neonates on day 1 and also in 29% of neonates on day 2. On day 3, there was no change in 50% of neonates and unknown change in 50% of neonates.

CONCLUSIONS

The results are reassuring regarding the safety of lacosamide in neonates. Although some neonates had fewer seizures after lacosamide administration, the lack of a comparator arm and reliance on qualitative statements in electroencephalographic reports limit the preliminary efficacy results.

Sequential levetiracetam and phenytoin in electroencephalographic neonatal seizures unresponsive to phenobarbital: a multicenter prospective observational study in India

Background

Although levetiracetam and phenytoin are widely used antiseizure medications (ASM) in neonates, their efficacy on seizure freedom is unclear. We evaluated electroencephalographic (EEG) seizure freedom following sequential levetiracetam and phenytoin in neonatal seizures unresponsive to phenobarbital.

Methods

We recruited neonates born ≥35 weeks and aged <72 h who had continued electrographic seizures despite phenobarbital, from three Indian hospitals, between 20 June 2020 and 31 July 2022. The neonates were treated with intravenous levetiracetam (20 mg/kg x 2 doses, second line) followed by phenytoin (20 mg/kg x 2 doses, third line) if seizures persisted. The primary outcome was complete seizure freedom, defined as an absence of seizures on EEG for at least 60 min within 40 min from the start of infusion.

Findings

Of the 206 neonates with continued seizures despite phenobarbital, 152 received levetiracetam with EEG. Of these one EEG was missing, 47 (31.1%) were in status epilepticus, and primary outcome data were available in 145. Seizure freedom occurred in 20 (13.8%; 95% CI 8.6%-20.5%) after levetiracetam; 16 (80.0%) responded to the first dose and 4 (20.0%) to the second dose. Of the 125 neonates with persisting seizures after levetiracetam, 114 received phenytoin under EEG monitoring. Of these, the primary outcome data were available in 104. Seizure freedom occurred in 59 (56.7%; 95% CI 46.7%-66.4%) neonates; 54 (91.5%) responded to the first dose and 5 (8.5%) to the second dose.

Interpretation

With the conventional doses, levetiracetam was associated with immediate EEG seizure cessation in only 14% of phenobarbital unresponsive neonatal seizures. Additional treatment with phenytoin along with levetiracetam attained seizure freedom in further 57%. Safety and efficacy of higher doses of levetiracetam should be evaluated in well-designed randomised controlled trials.

Funding

National Institute for Health and Care Research (NIHR) Research and Innovation for Global Health Transformation (NIHR200144).

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.

Factors associated with the development of epilepsy in very low birth weight infants

BACKGROUND

The survival rate of very low birth weight (VLBW) infants has recently improved. However, the occurrence of and factors associated with epilepsy in VLBW infants remain unknown. This study aimed to clarify the incidence, characteristics, and factors associated with epilepsy development in VLBW infants.

METHODS

All VLBW infants admitted to our hospital between 2012 and 2017 were included in this study. VLBW infants with a follow-up period of <1 year were excluded. Chromosomal abnormalities, brain anomalies, severe intraventricular hemorrhage (IVH), cystic periventricular leukomalacia (PVL), and hypoxic ischemic encephalopathy (HIE) were considered to be risk factors.

RESULTS

Epilepsy occurred in 21/526 (4.0%) VLBW infants. Chromosomal abnormalities, brain anomalies, severe IVH, cystic PVL, HIE, neonatal seizures, advanced maternal age, maternal diabetes mellitus, no administration of antenatal corticosteroids, and low Apgar scores at 1 and 5 min were associated with a risk of epilepsy. The median time to epilepsy onset was 8 months (range: 0-59 months), and the onset occurred within 2 years in 15/21 patients (71.4%) and within 4 years in 18/21 patients (85.7%). VLBW infants with risk factors developed epilepsy earlier and at a significantly higher rate than those without risk factors. Among infants who had risk factors and who developed epilepsy, 86.7% did so within 2 years of age, compared to 33.3% of those who developed epilepsy but did not have risk factors.

CONCLUSION

These findings regarding factors associated with a risk of development of epilepsy and temporal feature of epilepsy may contribute to the development of monitoring and treatment protocols for epilepsy in VLBW infants.

Neonatal seizures: Etiologies, clinical characteristics, and radiological features: A cross-sectional study

Seizures are a common clinical indication of central nervous system damage or abnormality in neonates. We aimed to identify the etiologies, clinical characteristics, and radiological features of neonatal seizures. This is a cross-sectional, retrospective, descriptive study using data obtained from the neonatal intensive care unit in King Abdulaziz Medical City (KAMC), a governmental, academic tertiary hospital in Riyadh, Saudi Arabia. The population of interest were neonates diagnosed with a neonatal seizure at KAMC between April 2015 and March 2019. A total of 61 patients with neonatal seizures were included in the study. The most common etiology was hypoxic-ischemic encephalopathy (43%). A total of 32 patients were full-term (52.5%). Around one-fifth of the study sample (21.3%) had a family history of neonatal seizures. Around 43.0% of the patients had epilepsy episodes. More than half of the patients (57.0%) were on one anti-seizure medication. Patients were followed up after 1 year, they had multiple comorbidities, including developmental delay, epilepsy, and cerebral palsy. Developmental delay was identified in 62.3% of the patients. A total of 19 patients have passed away (31%). Neonatal seizures are a common manifestation of neurologic disorders in neonates and are associated with high morbidity and mortality. Therefore, early identification of seizure etiology and proper management may help to improve the outcome.

ILAE Genetic Literacy Series: Self-limited familial epilepsy syndromes with onset in neonatal age and infancy

The self-limited (familial) epilepsies with onset in neonates or infants, formerly called benign familial neonatal and/or infantile epilepsies, are autosomal dominant disorders characterized by neonatal- or infantile-onset focal motor seizures and the absence of neurodevelopmental complications. Seizures tend to remit during infancy or early childhood and are therefore called "self-limited". A positive family history for epilepsy usually suggests the genetic etiology, but incomplete penetrance and de novo inheritance occur. Here, we review the phenotypic spectrum and the genetic architecture of self-limited (familial) epilepsies with onset in neonates or infants. Using an illustrative case study, we describe important clues in recognition of these syndromes, diagnostic steps including genetic testing, management, and genetic counseling.

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 Role of Amplitude-Integrated Electroencephalography (aEEG) in Monitoring Infants with Neonatal Seizures and Predicting Their Neurodevelopmental Outcome

Newborn monitoring in neonatal intensive care units (NICU) is mandatory, but neurological and especially electroencephalographic (EEG) monitoring can be overlooked or delayed until the newborn is clinically stable. However, the neonatal period is associated with the highest risk of seizures in humans, and the clinical symptoms may often be discrete, but the evolution and long-term neurodevelopmental disorders in these patients may be important. In response to this issue, we conducted a study to evaluate newborns who experienced neonatal seizures (NS) in the NICU and monitored their long-term neurological development. We enrolled 73 term and preterm newborns who underwent EEG monitoring using amplitude-integrated electroencephalography (aEEG). We then followed their neurological development until around 18 months of age, with 59 patients remaining in the long-term study. A total of 22% of patients with NS developed epilepsy, 12% cerebral palsy, 19% severe neurodevelopmental disabilities, and 8.5% died within the first 18 months of life. Our findings indicate that aEEG background pattern is a strong predictor of unfavorable neurological outcomes, with an odds ratio of 20.4174 (p < 0.05). Additionally, higher Apgar scores were associated with better outcomes (p < 0.05), with the odds of unfavorable neurological outcomes decreasing by 0.7-fold for every point increase in Apgar score. Furthermore, we found a statistically significant association between preterm birth and unfavorable neurological outcomes (p = 0.0104). Our study highlights the importance of early EEG monitoring in the NICU and provides valuable insights into predictors of unfavorable neurological outcomes in newborns who experienced NS.

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.

Comparison between Phenobarbitone and Levetiracetam as the initial anticonvulsant in preterm neonatal seizures - a pilot randomized control trial in developing country setup

This study aimed to compare the efficacy and safety of intravenous Levetiracetam and Phenobarbitone in the treatment of seizures in preterm neonates. It was an open-labeled, parallel randomized controlled trial conducted in a tertiary Neonatal Intensive Care Unit, India. Total 48 preterm neonates (28-36⁺⁶ weeks) with clinical seizures were randomized to receive either Levetiracetam (LEV; 40 mg/kg, then 20 mg/kg) or Phenobarbitone (PB; 15 mg/kg, then 10 mg/kg) intravenously as first loading dose in ratio 1:1; second loading was given for persistent seizure. Efficacy was denoted by cessation of clinical seizures with first or second doses of the allotted antiepileptic, and remaining seizure-free for the next 24 h. The demographic characteristics of preterm neonates and seizure types were comparable between both groups. Clinical seizure was controlled in 19 (79%) neonates in LEV group and 17 (70%) neonates in PB group, RR 1.12 (95% CI: 0.80 to 1.55), p = 0.504. There was increased respiratory support in PB group 9 (38%) vs. 3 (13%) in LEV group, RR 3.0 (95% CI: 0.92 to 9.74), p = 0.06.  Conclusion: Levetiracetam and Phenobarbitone were equally efficacious for clinical neonatal seizure control, but increased respiratory support was found with Phenobarbitone use. What is Known: • Preterm neonates are at higher risk of neonatal seizure and Phenobarbitone is commonly used as the first line antiepileptic drugs in treating them. What is New: • Levetiracetam found equally efficacious as Phenobarbitone for cessation of clinical seizures in preterm neonates, with less adverse effect.

Machine learning for the early prediction of infants with electrographic seizures in neonatal hypoxic-ischemic encephalopathy

OBJECTIVE

To assess if early clinical and electroencephalography (EEG) features predict later seizure development in infants with hypoxic-ischemic encephalopathy (HIE).

METHODS

Clinical and EEG parameters <12 h of birth from infants with HIE across eight European Neonatal Units were used to develop seizure-prediction models. Clinical parameters included intrapartum complications, fetal distress, gestational age, delivery mode, gender, birth weight, Apgar scores, assisted ventilation, cord pH, and blood gases. The earliest EEG hour provided a qualitative analysis (discontinuity, amplitude, asymmetry/asynchrony, sleep-wake cycle [SWC]) and a quantitative analysis (power, discontinuity, spectral distribution, inter-hemispheric connectivity) from full montage and two-channel amplitude-integrated EEG (aEEG). Subgroup analysis, only including infants without anti-seizure medication (ASM) prior to EEG was also performed. Machine-learning (ML) models (random forest and gradient boosting algorithms) were developed to predict infants who would later develop seizures and assessed using Matthews correlation coefficient (MCC) and area under the receiver-operating characteristic curve (AUC).

RESULTS

The study included 162 infants with HIE (53 had seizures). Low Apgar, need for ventilation, high lactate, low base excess, absent SWC, low EEG power, and increased EEG discontinuity were associated with seizures. The following predictive models were developed: clinical (MCC 0.368, AUC 0.681), qualitative EEG (MCC 0.467, AUC 0.729), quantitative EEG (MCC 0.473, AUC 0.730), clinical and qualitative EEG (MCC 0.470, AUC 0.721), and clinical and quantitative EEG (MCC 0.513, AUC 0.746). The clinical and qualitative-EEG model significantly outperformed the clinical model alone (MCC 0.470 vs 0.368, p-value .037). The clinical and quantitative-EEG model significantly outperformed the clinical model (MCC 0.513 vs 0.368, p-value .012). The clinical and quantitative-EEG model for infants without ASM (n = 131) had MCC 0.588, AUC 0.832. Performance for quantitative aEEG (n = 159) was MCC 0.381, AUC 0.696 and clinical and quantitative aEEG was MCC 0.384, AUC 0.720.

SIGNIFICANCE

Early EEG background analysis combined with readily available clinical data helped predict infants who were at highest risk of seizures, hours before they occur. Automated quantitative-EEG analysis was as good as expert analysis for predicting seizures, supporting the use of automated assessment tools for early evaluation of HIE.

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.

Neonatal seizures: diagnostic updates based on new definition and classification

Neonatal seizures are the most common neurological symptoms caused by various etiologies in the neonatal period, but their diagnosis and treatment are challenging because their pathophysiology and electroclinical manifestations differ from those of patients in older age groups. Many seizures present as electrographic-only events without clinical signs or as obscure clinical manifestations that are difficult to distinguish from other neonatal behaviors. Accordingly, a new definition and classification of neonatal seizures was recently proposed by the International League Against Epilepsy Task Force on neonatal seizures, highlighting the role of electroencephalography in diagnosing and treating neonatal seizures. Neonatal seizures are defined as electrographic events with sudden, paroxysmal, and abnormal alteration of activity and divided into electroclinical seizures and electrographic-only seizures according to their clinical signs, thus excluding clinical events without an electrographic correlation. Seizure types are described by their predominant clinical features and divided into motor (automatisms, clonic, epileptic spasms, myoclonic, tonic, and sequential), nonmotor (autonomic and behavioral arrest), and unclassified. Although many neonatal seizures are acute reactive events caused by hypoxic-ischemic encephalopathy or vascular insults, structural, genetic, or metabolic etiologies of neonatal-onset epilepsy should also be thoroughly evaluated to determine their appropriate management.

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.

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.

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.

Safety of Early Discontinuation of Antiseizure Medication After Acute Symptomatic Neonatal Seizures

Question

Is discontinuation of antiseizure medication (ASM) after resolution of acute symptomatic neonatal seizures and prior to discharge from the hospital associated with functional neurodevelopment or epilepsy at 24 months?

Findings

In this comparative effectiveness study of 303 children with neonatal seizures from 9 centers, 64% had ASM maintained at hospital discharge. No difference was found between ASM maintenance and discontinuation groups in functional neurodevelopment or epilepsy; 13% of children developed epilepsy, including more than one-third with infantile spasms.

Meaning

These results support discontinuing ASMs for most neonates with acute symptomatic seizures prior to discharge from the hospital, an approach that may represent an evidence-based change in practice for many clinicians.

Importance

Antiseizure medication (ASM) treatment duration for acute symptomatic neonatal seizures is variable. A randomized clinical trial of phenobarbital compared with placebo after resolution of acute symptomatic seizures closed early owing to low enrollment.

Objective

To assess whether ASM discontinuation after resolution of acute symptomatic neonatal seizures and before hospital discharge is associated with functional neurodevelopment or risk of epilepsy at age 24 months.

Design, Setting, and Participants

This comparative effectiveness study included 303 neonates with acute symptomatic seizures (282 with follow-up data and 270 with the primary outcome measure) from 9 US Neonatal Seizure Registry centers, born from July 2015 to March 2018. The centers all had level IV neonatal intensive care units and comprehensive pediatric epilepsy programs. Data were analyzed from June 2020 to February 2021.

Exposures

The primary exposure was duration of ASM treatment dichotomized as ASM discontinued vs ASM maintained at the time of discharge from the neonatal seizure admission. To enhance causal association, each outcome risk was adjusted for propensity to receive ASM at discharge. Propensity for ASM maintenance was defined by a logistic regression model including seizure cause, gestational age, therapeutic hypothermia, worst electroencephalogram background, days of electroencephalogram seizures, and discharge examination (all P ≤ .10 in a joint model except cause, which was included for face validity).

Main Outcomes and Measures

Functional neurodevelopment was assessed by the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS) at 24 months powered for propensity-adjusted noninferiority of early ASM discontinuation. Postneonatal epilepsy, a prespecified secondary outcome, was defined per International League Against Epilepsy criteria, determined by parent interview, and corroborated by medical records.

Results

Most neonates (194 of 303 [64%]) had ASM maintained at the time of hospital discharge. Among 270 children evaluated at 24 months (mean [SD], 23.8 [0.7] months; 147 [54%] were male), the WIDEA-FS score was similar for the infants whose ASMs were discontinued (101 of 270 [37%]) compared with the infants with ASMs maintained (169 of 270 [63%]) at discharge (median score, 165 [interquartile range, 150-175] vs 161 [interquartile range, 129-174]; P = .09). The propensity-adjusted average difference was 4 points (90% CI, −3 to 11 points), which met the a priori noninferiority limit of −12 points. The epilepsy risk was similar (11% vs 14%; P = .49), with a propensity-adjusted odds ratio of 1.5 (95% CI, 0.7-3.4; P = .32).

Conclusions and Relevance

In this comparative effectiveness study, no difference was found in functional neurodevelopment or epilepsy at age 24 months among children whose ASM was discontinued vs maintained at hospital discharge after resolution of acute symptomatic neonatal seizures. These results support discontinuation of ASM prior to hospital discharge for most infants with acute symptomatic neonatal seizures.

Novel Therapeutics for Neonatal Seizures

Neonatal seizures are a common neurologic emergency for which therapies have not significantly changed in decades. Improvements in diagnosis and pathophysiologic understanding of the distinct features of acute symptomatic seizures and neonatal-onset epilepsies present exceptional opportunities for development of precision therapies with potential to improve outcomes. Herein, we discuss the pathophysiology of neonatal seizures and review the evidence for currently available treatment. We present emerging therapies in clinical and preclinical development for the treatment of acute symptomatic neonatal seizures. Lastly, we discuss the role of precision therapies for genetic neonatal-onset epilepsies and address barriers and goals for developing new therapies for clinical care.

Clinical profile, aetiology, short-term outcome and predictors of poor outcome of neonatal seizures among out-born neonates admitted to a neonatal unit in Paediatric emergency of a tertiary care hospital in North India: A prospective observational study

Neonatal seizures are common manifestations of several neurological or systemic disorders and associated with high morbidity, mortality and poor short- and long-term developmental outcomes. It is important to determine the aetiology and factors that determine the poor outcome, more so in a newly developed setting. The early detection of predictors of poor outcome will help in planning acute management, counselling, follow-up and rehabilitation services. In this prospective observational study, we looked at the clinical profile, aetiology, short-term outcomes and predictors of poor outcome of neonatal seizures among out-born neonates. The common causes were hypoxic ischaemic encephalopathy, sepsis and metabolic disturbances. One-third of neonates had poor outcome. Abnormal neurological and cardiorespiratory examination at admission; low oxygen saturation, glucose and pH; and hypoxic ischemic encephalopathy-III were predictors of poor outcome.

Neonatal Antiepileptic Medication Treatment Patterns: A Decade of Change

OBJECTIVE

This study aims to describe the frequency and characteristics of anticonvulsant medication treatments initiated in the neonatal period.

STUDY DESIGN

We analyzed a cohort of neonates with a seizure diagnosis who were discharged from institutions in the Pediatric Health Information System between 2007 and 2016. Adjusted risk ratios and 95% confidence intervals for characteristics associated with neonatal (≤ 28 days postnatal) anticonvulsant initiation were calculated via modified Poisson regression.

RESULTS

A total of 6,245 infants from 47 institutions were included. There was a decrease in both phenobarbital initiation within the neonatal period (96.9 to 91.3%, p = 0.015) and continuation at discharge (90.6 to 68.6%, p <0.001). Levetiracetam (7.9 to 39.6%, p < 0.001) initiation within the neonatal period and continuation at discharge (9.4 to 49.8%, p < 0.001) increased. Neonates born at ≥ 37 weeks' gestation and those diagnosed with intraventricular hemorrhage, ischemic/thrombotic stroke, other hemorrhagic stroke, and hypoxic ischemic encephalopathy (HIE) had a higher probability of anticonvulsant administration. The most prevalent diagnosis was HIE (n = 2,223, 44.4%).

CONCLUSION

Phenobarbital remains the most widely used neonatal seizure treatment. Levetiracetam is increasingly used as a second line therapy. Increasing levetiracetam use indicates a need for additional study to determine its effectiveness in reducing seizure burden and improving long-term outcomes.

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.

Moderately and Late Preterm Infants: Short- and Long-Term Outcomes From a Registry-Based Cohort

Background: While most studies on the association of preterm birth and cerebral palsy (CP) have focused on very preterm infants, lately, attention has been paid to moderately preterm [32 to <34 weeks gestational age (GA)] and late preterm infants (34 to <37 weeks GA).

Methods: In order to report on the outcomes of a cohort of moderately and late preterm infants, derived from a population-based CP Registry, a comparative analysis of data on 95 moderately preterm infants and 96 late preterm infants out of 1,016 with CP, was performed.

Results: Moderately preterm neonates with CP were more likely to have a history of N-ICU admission (p = 0.001) and require respiratory support (p < 0.001) than late preterm neonates. Birth weight was significantly related to early neonatal outcome with children with lower birth weight being more likely to have a history of N-ICU admission [moderately preterm infants (p = 0.006)/late preterm infants (p < 0.001)], to require ventilator support [moderately preterm infants (p = 0.025)/late preterm infants (p = 0.014)] and not to have neonatal seizures [moderately preterm infants (p = 0.044)/late preterm infants (p = 0.263)]. In both subgroups, the majority of children had bilateral spastic CP with moderately preterm infants being more likely to have bilateral spastic CP and less likely to have ataxic CP as compared to late preterm infants (p = 0.006). The prevailing imaging findings were white matter lesions in both subgroups, with statistically significant difference between moderately preterm infants who required ventilator support and mainly presented with this type of lesion vs. those who did not and presented with gray matter lesions, maldevelopments or miscellaneous findings. Gross motor function was also assessed in both subgroups without significant difference. Among late preterm infants, those who needed N-ICU admission and ventilator support as neonates achieved worse fine motor outcomes than those who did not.

Conclusions: Low birth weight is associated with early neonatal problems in both moderately and late preterm infants with CP. The majority of children had bilateral spastic CP and white matter lesions in neuroimaging. GMFCS levels were comparable in both subgroups while BFMF was worse in late preterm infants with a history of N-ICU admission and ventilator support.

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.

Seizures in the neonate: A review of etiologies and outcomes

Neonatal seizures occur in their majority in close temporal relation to an acute brain injury or systemic insult, and are accordingly defined as acute symptomatic or provoked seizures. However less frequently, unprovoked seizures may also present in the neonatal period as secondary to structural brain abnormalities, thus corresponding to structural epilepsies, or to genetic conditions, thus corresponding to genetic epilepsies. Unprovoked neonatal seizures should be thus considered as the clinical manifestation of early onset structural or genetic epilepsies that often have the characteristics of early onset epileptic encephalopathies. In this review, we address the conundrum of neonatal seizures including acute symptomatic, remote symptomatic, provoked, and unprovoked seizures, evolving to post-neonatal epilepsies, and neonatal onset epilepsies. The different clinical scenarios involving neonatal seizures, each with their distinct post-neonatal evolution are presented. The structural and functional impact of neonatal seizures on brain development and the concept of secondary epileptogenesis, with or without a following latent period after the acute seizures, are addressed. Finally, we underline the need for an early differential diagnosis between an acute symptomatic seizure and an unprovoked seizure, since it is associated with fundamental differences in clinical evolution. These are crucial aspects for neonatal management, counselling and prognostication. In view of the above aspects, we provide an outlook on future strategies and potential lines of research in this field.

Preterm Brain Injury, Antenatal Triggers, and Therapeutics: Timing Is Key

With a worldwide incidence of 15 million cases, preterm birth is a major contributor to neonatal mortality and morbidity, and concomitant social and economic burden Preterm infants are predisposed to life-long neurological disorders due to the immaturity of the brain. The risks are inversely proportional to maturity at birth. In the majority of extremely preterm infants (<28 weeks' gestation), perinatal brain injury is associated with exposure to multiple inflammatory perinatal triggers that include antenatal infection (i.e., chorioamnionitis), hypoxia-ischemia, and various postnatal injurious triggers (i.e., oxidative stress, sepsis, mechanical ventilation, hemodynamic instability). These perinatal insults cause a self-perpetuating cascade of peripheral and cerebral inflammation that plays a critical role in the etiology of diffuse white and grey matter injuries that underlies a spectrum of connectivity deficits in survivors from extremely preterm birth. This review focuses on chorioamnionitis and hypoxia-ischemia, which are two important antenatal risk factors for preterm brain injury, and highlights the latest insights on its pathophysiology, potential treatment, and future perspectives to narrow the translational gap between preclinical research and clinical applications.

Evaluation of the Neonate with Seizures

Neonatal seizures are common, occurring in 2 to 5 of 1,000 live births in the United States. The neonatal brain is thought to be predisposed toward seizures due to a combination of excessive excitatory and deficient inhibitory neuronal activity. The seizures tend to be focal or multifocal without secondary generalization, resulting in subtle seizure appearance. There are five main categories of neonatal seizures: focal clonic, focal tonic, myoclonic, subtle, and generalized tonic. An electroencephalogram is recommended to diagnose and treat neonatal seizures due to poor reliability of the clinical examination. Causes of neonatal seizures are broad, including trauma, structural brain anomalies, infections, metabolic disorders, drug withdrawal or intoxication, and neonatal epilepsy syndromes. Treatment of neonatal seizures involves management of cardiorespiratory status, correction of metabolic derangements, and antiepileptics as needed. The most common antiepileptics used in neonates are phenobarbital, levetiracetam, and fosphenytoin. The long-term risk of neurodevelopmental disability varies depending upon the etiology of neonatal seizures. Close attention to developmental milestones and neurology follow-up is recommended for all neonates with seizures. [Pediatr Ann. 2020;49(7):e292-e298.].

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.

Applications of advanced signal processing and machine learning in the neonatal hypoxic-ischemic electroencephalogram

Perinatal hypoxic-ischemic-encephalopathy significantly contributes to neonatal death and life-long disability such as cerebral palsy. Advances in signal processing and machine learning have provided the research community with an opportunity to develop automated real-time identification techniques to detect the signs of hypoxic-ischemic-encephalopathy in larger electroencephalography/amplitude-integrated electroencephalography data sets more easily. This review details the recent achievements, performed by a number of prominent research groups across the world, in the automatic identification and classification of hypoxic-ischemic epileptiform neonatal seizures using advanced signal processing and machine learning techniques. This review also addresses the clinical challenges that current automated techniques face in order to be fully utilized by clinicians, and highlights the importance of upgrading the current clinical bedside sampling frequencies to higher sampling rates in order to provide better hypoxic-ischemic biomarker detection frameworks. Additionally, the article highlights that current clinical automated epileptiform detection strategies for human neonates have been only concerned with seizure detection after the therapeutic latent phase of injury. Whereas recent animal studies have demonstrated that the latent phase of opportunity is critically important for early diagnosis of hypoxic-ischemic-encephalopathy electroencephalography biomarkers and although difficult, detection strategies could utilize biomarkers in the latent phase to also predict the onset of future seizures.

Efficacy of antiepileptic drugs in neonatal seizures: a systematic review protocol

INTRODUCTION

Seizures are one of the most common neurological disorders of neonates, which is also an emergency in the neonatal intensive care unit. For neonates, the recommended first-line antiepileptic drugs (AEDs) include phenobarbitone, which may be effective in only 50% of seizures. Some new AEDs, such as levetiracetam, have been shown to be effective in adults and older children. However, their efficacy for neonatal seizures remains uncertain. The aim of this investigation is to conduct a systematic review to evaluate the efficacy of all AEDs in neonates. Additionally, the long-term outcomes following neonatal seizures, in relation to the development of cerebral palsy and epilepsy, will be studied.

METHOD

We will perform a systematic review including randomised controlled studies (RCTs), cohort studies, case-controlled studies and case series studies which evaluated the efficacy of AEDs and short-term and long-term outcomes in neonatal seizures. PubMed, Embase, Web of Science, Cochrane Library and Clinical trial.gov will be searched. There will be no language restriction. Risk bias in RCTs will be evaluated by the Cochrane risk-of-bias tool, while cohort and case-control studies will be evaluated by the Newcastle-Ottawa Scale. A network meta-analysis will be performed by the Bayesian model using WinBUGS V.1.4.3 and R software if there is a high degree of homogeneity among studies. Otherwise, we will perform a narrative review without pooling. Subgroup analyses will be performed in different AEDs and dosage groups.

OUTCOME

The primary outcomes will be seizure cessation confirmed by electroencephalogram and long-term neurodevelopmental outcome. Secondary outcomes will be neonatal mortality during hospitalisation and suspected drug toxicity.

ETHICS AND DISSEMINATION

Formal ethical approval is not required as no primary data are collected. This systematic review will be disseminated through a peer-reviewed publication.

Effectiveness of low dose of rapamycin in preventing seizure-induced anxiety-like behaviour, cognitive impairment, and defects in neurogenesis in developing rats

Aims: Previous studies have demonstrated that rapamycin prevents seizure-induced anxiety-like behaviors. However, rapamycin had been used at a higher dose of 3 mg/kg and resulted in side effects in immature animals. This work was designed to explore whether a lower dose of rapamycin has similar efficacy but has milder side effects.Methods: Acute seizures were induced by injection of pilocarpine at postnatal 10-day Sprague-Dawley rats. Western blot analysis was used to detect changes in mammalian target of rapamycin (mTOR) pathway after seizure. Immunofluorescent intensity of doublecortin (DCX) was conducted to evaluate the development of neurons in hippocampus. Morris water maze and Y-maze test were used to assess cognitive functions and open-field test and elevated plus maze were used to detect anxiety-like behaviors 4 weeks after seizure onset.Results: mTOR pathway was abnormally activated with two peaks after pilocarpine-induced seizures, and no difference of DCX-positive cells and body weight were noticed between control and pilocarpine-induced seizure rats. Pilocarpine-induced seizure in postnatal 10 days rats did not exert impairment on cognitive functions, but resulted in obvious anxiety-like behaviors. Low dose of rapamycin at 0.3 mg/kg significantly reversed seizure-induced increase of p-S6 levels as well as abnormal anxiety-like behaviors. In addition, rapamycin at the dose of 0.3mg/kg did not affect normal development and cognitive functions.Conclusion: lower doses of rapamycin should be used in infants compared with older children or adults.

Characterisation of neonatal seizures and their treatment using continuous EEG monitoring: a multicentre experience

OBJECTIVE

The aim of this multicentre study was to describe detailed characteristics of electrographic seizures in a cohort of neonates monitored with multichannel continuous electroencephalography (cEEG) in 6 European centres.

METHODS

Neonates of at least 36 weeks of gestation who required cEEG monitoring for clinical concerns were eligible, and were enrolled prospectively over 2 years from June 2013. Additional retrospective data were available from two centres for January 2011 to February 2014. Clinical data and EEGs were reviewed by expert neurophysiologists through a central server.

RESULTS

Of 214 neonates who had recordings suitable for analysis, EEG seizures were confirmed in 75 (35%). The most common cause was hypoxic-ischaemic encephalopathy (44/75, 59%), followed by metabolic/genetic disorders (16/75, 21%) and stroke (10/75, 13%). The median number of seizures was 24 (IQR 9-51), and the median maximum hourly seizure burden in minutes per hour (MSB) was 21 min (IQR 11-32), with 21 (28%) having status epilepticus defined as MSB>30 min/hour. MSB developed later in neonates with a metabolic/genetic disorder. Over half (112/214, 52%) of the neonates were given at least one antiepileptic drug (AED) and both overtreatment and undertreatment was evident. When EEG monitoring was ongoing, 27 neonates (19%) with no electrographic seizures received AEDs. Fourteen neonates (19%) who did have electrographic seizures during cEEG monitoring did not receive an AED.

CONCLUSIONS

Our results show that even with access to cEEG monitoring, neonatal seizures are frequent, difficult to recognise and difficult to treat.

OBERSERVATION STUDY NUMBER

NCT02160171.

Recommendations for the design of therapeutic trials for neonatal seizures

Although seizures have a higher incidence in neonates than any other age group and are associated with significant mortality and neurodevelopmental disability, treatment is largely guided by physician preference and tradition, due to a lack of data from well-designed clinical trials. There is increasing interest in conducting trials of novel drugs to treat neonatal seizures, but the unique characteristics of this disorder and patient population require special consideration with regard to trial design. The Critical Path Institute formed a global working group of experts and key stakeholders from academia, the pharmaceutical industry, regulatory agencies, neonatal nurse associations, and patient advocacy groups to develop consensus recommendations for design of clinical trials to treat neonatal seizures. The broad expertise and perspectives of this group were invaluable in developing recommendations addressing: (1) use of neonate-specific adaptive trial designs, (2) inclusion/exclusion criteria, (3) stratification and randomization, (4) statistical analysis, (5) safety monitoring, and (6) definitions of important outcomes. The guidelines are based on available literature and expert consensus, pharmacokinetic analyses, ethical considerations, and parental concerns. These recommendations will ultimately facilitate development of a Master Protocol and design of efficient and successful drug trials to improve the treatment and outcome for this highly vulnerable population.

Outcome in preterm infants with seizures

Most neonatal seizures in preterm newborns are of acute symptomatic origin with a prevalence higher than in full-term infants. To date, recommendations for management of seizures in preterm newborns are scarce and do not differ from those in full-term newborns. Mortality in preterm newborns with seizures has significantly declined over the last decades, from figures of 84%-94% in the 1970s and 1980s to 22%-45% in the last years. However, mortality is significantly higher in those with a birth weight<1000g and a gestational age<28 weeks. Seizures are a strong predictor of unfavorable outcomes, including not only cerebral palsy, epilepsy, and intellectual disability, but also vision, hearing impairment, and microcephaly. The majority of patients with developmental delay are severely affected and this is usually associated with cerebral palsy. Furthermore, the incidence of epilepsy after neonatal seizures seems to be lower in preterm than in full-term infants but the risk is approximately 40 times greater than in the general population. Clinical studies cannot disentangle the specific and independent contributions of seizure-induced functional changes and the role of etiology and brain damage severity in determining the long-term outcomes in these newborns.

Diagnosis of seizures and encephalopathy using conventional EEG and amplitude integrated EEG

Seizures are more common in the neonatal period than at any other time of life, partly due to the relative hyperexcitability of the neonatal brain. Brain monitoring of sick neonates in the NICU using either conventional electroencephalography or amplitude integrated EEG is essential to accurately detect seizures. Treatment of seizures is important, as evidence increasingly indicates that seizures damage the brain in addition to that caused by the underlying etiology. Prompt treatment has been shown to reduce seizure burden with the potential to ameliorate seizure-mediated damage. Neonatal encephalopathy most commonly caused by a hypoxia-ischemia results in an alteration of mental status and problems such as seizures, hypotonia, apnea, and feeding difficulties. Confirmation of encephalopathy with EEG monitoring can act as an important adjunct to other investigations and the clinical examination, particularly when considering treatment strategies such as therapeutic hypothermia. Brain monitoring also provides useful early prognostic indicators to clinicians. Recent use of machine learning in algorithms to continuously monitor the neonatal EEG, detect seizures, and grade encephalopathy offers the exciting prospect of real-time decision support in the NICU in the very near future.

Seizure classification, etiology, and management

The first weeks of life are a time of heightened risk for seizures due to age-dependent physiologic features of the developing brain that lead to increased neuronal excitation and decreased inhibition. Usually, seizures in neonates are a symptom of an acute brain injury; seizures are only rarely due to neonatal-onset epilepsy syndromes. Neonatal seizures are harmful to the developing brain; early and accurate diagnosis is critical. For suspected seizures, EEG monitoring should be initiated as soon as is feasible, in order to evaluate for events of concern, screen for subclinical seizures, and assess the EEG background. Amplitude-integrated EEG can provide excellent complementary data, particularly with regard to evolution of background patterns, but has limited sensitivity to detect individual neonatal seizures. An urgent and systematic approach to precise etiologic diagnosis is key for optimal management and estimates of prognosis. Evaluation of the seizure etiology must occur in parallel with initiation of appropriate treatment. It is critical that neonatologists and neurologists develop hospital-specific, consensus-based practice pathways for neonatal seizure evaluation and treatment. Such practice pathways can streamline medical decision making, facilitate rapid medication administration, and potentially decrease seizure burden and optimize outcomes. Herein, the pathophysiology, epidemiology, treatment, and long-term management considerations for neonatal seizures are presented.

Seizures in newborn infants without hypoxic ischemic encephalopathy - antenatal and labor-related risk factors: a case-control study

Objective: To identify antepartum and intrapartum risk factors for neonatal seizures in the absence of hypoxic ischemic encephalopathy (HIE).Methods: Population-based case-control study. Of 98 484 births, 40 newborns at 34 gestational weeks or later had seizures within the first 7 days of life. Cases (n = 40) and controls (n = 160) were retrieved from the University hospitals of Örebro for 1994-2013 and Uppsala for 2003-2013. Demographics and characteristics of pregnancy, labor, delivery, and neonatal data were analyzed. Crude odds ratio (OR) and adjusted odds ratios (AOR) with 95% confidence intervals (CIs) for antenatal and intrapartum factors were calculated using logistic regression analysis. Main outcome measure was neonatal seizures within the first 7 days of life.Results: The incidence of neonatal seizures without HIE was 0.41/1000 live births. Antenatal risk factors for neonatal seizures were as follows: short maternal stature (AOR: 5.4; 1.8-16.5); previous caesarean section (AOR: 4.8; 1.5-15.0); and assisted fertilization (AOR: 6.8; 1.3-35.2). Intrapartum risk factors were as follows: induction of labor (AOR: 5.7; 1.8-17.7); preterm birth (AOR: 13.5; 3.7-48.9); and head circumference >37 cm (AOR: 6.9; 1.4-34.8).Conclusions: Preterm birth was the strongest risk factor for neonatal seizures in the absence of HIE. The results also indicate that feto-pelvic disproportion is associated with the occurrence of seizures.Rationale: Antepartum and intrapartum risk factors for newborn seizures in the absence of HIE were investigated in a case-control study. Out of 98 484 births at 34 gestational weeks or more, 40 newborns had seizures without HIE. All had a normal Apgar score although they later presented with seizures. Preterm birth was the strongest risk factor (OR: 13.5; 95% CI: 3.7-48.9). Our results also indicate that feto-pelvic disproportion is of importance. Furthermore, a history of prior caesarean was associated with seizures. This is the first study to assess obstetric risk factors for newborn seizures separate from those with seizures and concomitant HIE. The distinction is of importance due to different etiologies, treatments, and preventive strategies.

Heart rate variability in neonatal patients with seizures

OBJECTIVE

Seizures are frequently observed in neurological conditions affecting newborns. Since autonomic alterations are commonly associated with neonatal seizures (NS), we investigated the utility of heart rate variability (HRV) indexes of cardiac autonomic regulation for NS detection.

METHODS

HRV analysis was conducted on ECG tracings recorded during video-EEG monitoring in newborns with NS and matched-controls. The effects of gestational age on HRV were also evaluated.

RESULTS

Newborns with NS showed lower resting state HRV compared to controls. Moreover, seizure episodes were characterized by a short-lasting increase in vagal indexes of HRV. Pre-term newborns with NS had a lower HRV than full-term at rest. In pre-term newborns, no changes in HRV were observed before and during NS. On the contrary, full-term newborns showed significantly higher HRV before and during NS compared to the respective baseline values.

CONCLUSION

Our data point to resting autonomic impairment in newborns with NS. In addition, an increment in HRV has been observed during NS only in full term newborns.

SIGNIFICANCE

Although these findings do not allow validation of HRV measures for NS prediction and detection, they suggest that a putative protective vagal mechanism might be adopted when an advanced maturation of autonomic nervous system is achieved.

Predictive value of early EEG for seizures in neonates with hypoxic-ischemic encephalopathy undergoing therapeutic hypothermia

OBJECTIVES

To assess the prognostic significance of an early normal/mildly abnormal conventional EEG (cEEG) on seizure risk in neonates undergoing therapeutic hypothermia.

METHODS

We reviewed the video-EEG recordings from a large cohort of neonates treated with therapeutic hypothermia for hypoxic-ischemic encephalopathy from 2008 to 2017 in a single tertiary center. Continuous video-EEG was started as soon as possible (median 8.2 h) and continued throughout hypothermia and rewarming. We studied those neonates with a normal/mildly abnormal EEG during the first 24 h of monitoring.

RESULTS

A total of 331 neonates were treated with hypothermia and 323 had cEEG recordings available for review; 99 were excluded because of a moderately/severely abnormal cEEG background and/or seizure during the first 24 h of recording, and an additional eight because of early rewarming. The remaining 216 had a normal/mildly abnormal cEEG in the first 24 h. None of these patients subsequently developed seizures.

CONCLUSION

A normal/mildly abnormal cEEG during the first 24 h indicates a very low risk of subsequent seizures. This suggests that cEEG monitoring can be safely discontinued after 24 h if it has remained normal or excessively discontinuous and no seizures are detected, limiting the need for this resource-intensive and expensive tool.

Incidence of neonatal seizures, perinatal risk factors for epilepsy and mortality after neonatal seizures in the province of Parma, Italy

OBJECTIVE

Information about the incidence of neonatal seizures (NS) is scarce. Previous studies relied primarily on a clinical diagnosis of seizures. This population-based, retrospective study evaluated the incidence of electroencephalography (EEG)-confirmed seizures in neonates born in the province of Parma and the perinatal risk factors for mortality and epilepsy.

METHODS

All neonates with suspected seizures or with medical conditions at high risk for seizures from the study area were recorded in the neonatal intensive care unit (NICU) of the Parma University Hospital. NS were EEG confirmed. Perinatal risk factors for mortality and epilepsy after NS were evaluated with Cox's proportional hazards models.

RESULTS

In a 13-year period, 112 patients presented with NS: 102 newborns had electroclinical seizures (46 full-term and 56 preterm), whereas 10 presented only electrical seizures. The incidence was 2.29/1000 live births (95% confidence interval [CI] 1.87-2.72), with higher rates in preterm neonates (14.28/1000 in preterm vs 1.10/1000 in full-term infants). The incidence increased with decreasing gestational age (31-36 weeks of gestation: 5.01/1000, 28-30: 54.9/1000, and <28: 85.6/1000) and with decreasing birth weight (≥2500 g: 1.19/1000, <1000 g: 127.57/1000). Twenty-eight patients (25%) died, 16 (14.3%) had a diagnosis of epilepsy, 33 (29.5%) had cerebral palsy, and 39 (34.8%) had a developmental delay. Among the perinatal risk factors considered, the multivariate analysis showed an association between a 5-minute Apgar score of 0-7 and etiology with increased mortality and between female gender and status epilepticus with epilepsy.

SIGNIFICANCE

The incidence of NS is inversely associated with gestational age and birth weight. The etiology and a low Apgar score are strongly related to mortality; female gender and status epilepticus are risk factors for the development of epilepsy.

Outcomes After Acute Symptomatic Seizures in Children Admitted to a Neonatal Neurocritical Care Service

BACKGROUND

Neonatal seizures due to acute brain injury are associated with high rates of death, disability, and epilepsy. Our objective was to examine incidence of and risk factors for epilepsy among survivors of acute symptomatic neonatal seizures who were cared for by a neonatal neurocritical care service.

METHODS

Neonates with acute symptomatic seizures who were admitted to UCSF Benioff Children's Hospital Neuro-Intensive Care Nursery from July 2008 to June 2014 were considered for inclusion.

RESULTS

A total of 144 children with acute symptomatic seizures met study criteria and 37 (26%) died before age one. Eighty-seven children (85% of eligible survivors) were followed up to one year or longer. Epilepsy was diagnosed in eight children at median age 4.9 (interquartile range 1.7, 6.1) years. The cumulative incidence risk of epilepsy at one year was 2% (95% confidence interval 0.6% to 9%) and at five years was 7% (95% confidence interval 3% to 20%). Cerebral palsy was diagnosed in 21%. Bayley-III cognitive subscale less than 85 was present in 13%. Children with epilepsy were more likely to be preterm, have brain injury, and be discharged home on antiseizure medication, although the results were not significant after adjusted analysis.

CONCLUSIONS

The risk of epilepsy was lower and age at onset was older than in previous reports, which may be related to multiple factors including a neurocritical care approach, treatment of hypoxic-ischemic encephalopathy with hypothermia, high rate of neonatal transition to palliative care, and the exclusion of neonatal onset epilepsies. Continuation of antiseizure medications in infancy did not decrease the risk of epilepsy. Long-term, multicenter studies are needed to understand whether neonatal seizure management can alter the risk of epilepsy.

Acute symptomatic neonatal seizures in preterm neonates: etiologies and treatments

Acute symptomatic neonatal seizures in preterm newborns are a relevant clinical challenge due to the presence of many knowledge gaps. Etiology-wise, acute symptomatic seizures have an age-specific epidemiology, with intraventricular hemorrhage and its complications representing the first cause in extremely and very preterm neonates, whereas other etiologies have similar occurrence rates as in full-term infants. Specific treatment strategies for the premature neonates are not yet available. Studies suggest a similarly low response rate with even more unfavorable prognosis than in full-term infants. Pharmacodynamic and pharmacokinetic changes are likely under way during the preterm period, with the potential to affect both effectiveness and safety of antiepileptic drugs in these patients. However, due to the lack of clear evidence to guide prioritization of second-line drugs, off-label medications are frequently indicated by review papers and flow-charts, and are prescribed in clinical practice. We therefore conclude by exploring potential future lines of research.

Outcomes after acute symptomatic seizures in neonates

Acute symptomatic seizures are a common sign of neurological dysfunction and brain injury in neonates and occur in approximately one to three per 1000 live births. Seizures in neonates are usually a sign of underlying brain injury and, as such, are commonly associated with adverse outcomes. Neurological morbidities in survivors often co-occur; epilepsy, cerebral palsy, and intellectual disability often occur together in the most severely affected children. Risk factors for adverse outcome include prematurity, low Apgar scores, low pH on the first day of life, seizure onset <24 or >72 h after birth, abnormal neonatal neurological examination, abnormal neonatal electroencephalographic background, status epilepticus, and presence and pattern of brain injury (particularly deep gray or brainstem injury). Despite this list of potential indicators, accurate prediction of outcome in a given child remains challenging. There is great need for long-term, multicenter studies to examine risk factors for, and pathogenesis of, adverse outcomes following acute symptomatic seizures in neonates.