Epilepsy after neonatal seizures: literature review

High-frequency oscillations in neonatal EEG and their association with epilepsy

OBJECTIVE

We assessed high-frequency oscillations (HFOs) in neonatal EEG hypothesizing that HFOs would be prevalent in neonates with prevailing or forthcoming severe epilepsy, fewer in those with benign epilepsy or acute provoked seizures, and absent in healthy neonates.

METHODS

From a population-derived EEG database, we identified neonates with neonatal-onset epilepsy, chronic brain disease, acute stroke, perinatal hypoxic ischemic encephalopathy, acute brain infection, or no neurological diagnoses. We marked sleep stages, seizures, and HFOs manually, and evaluated outcome from medical records.

RESULTS

HFOs were detected in 29/98 (30 %) neonates, of whom 10 had ictal (median rate 0.53/min, range 0.07-6.41/min) and 24 had nonictal HFOs (median rate 0.20/min, range 0.01-20.99/min). Nonictal HFO occurrence and rate were significantly i) higher in neonates with neonatal-onset developmental and epileptic encephalopathy (DEE) than most other diagnostic groups, and ii) higher in neonates that later developed infantile-onset DEE (p < 0.05) than those surviving without DEE. Ictal HFOs were common during acute provoked seizures and were not linked with epilepsy.

CONCLUSIONS

Neonatal nonictal HFOs were associated with prevailing or forthcoming early-onset DEE.

SIGNIFICANCE

Our data support the hypotheses that neonatal scalp HFOs are i) pathological, ii) associated with epilepsy severity, and iii) a marker of epileptogenesis.

Neonatal seizures: A cohort evaluation at a pediatric referral center

OBJECTIVE

Neonatal seizures have an incidence of 1-5/1000 newborns. Their clinical, etiology, and therapeutic characterization is a clinical challenge. The objective of this study was to characterize neonatal seizures recorded over 6 years, considering the clinical presentation, management, and follow-up.

METHODS

A retrospective analysis of clinical, neurophysiological (video-electroencephalogram), and imaging data of all newborns who had suspected neonatal seizures with electroencephalographic findings (paroxysmal activity, electrographic-only seizures, and/or electroclinical seizures) was performed. The study considered all cases that occurred between January 2010 and December 2015, with the respective follow-up equal to or longer than 7 years.

RESULTS

Seizures were diagnosed in 85 newborns, 87.1% within the first 48 h of life. In 72.9% of suspected cases, only paroxysmal activity in the v-EEG was recorded, in another 16.5% electrical-only seizures were found, and in 10.6% there were electroclinical seizures. Epilepsy was diagnosed in 23.5% of cases, with 14% currently maintaining therapy. Motor sequelae occurred in 44.3% of children and 41.4% had normal neurological examination. There were also 11.4% of deaths in the neonatal period.

SIGNIFICANCE

Neonatal seizures occur mostly in the first 48 h of life and mainly due to hypoxic-ischemic injuries. During follow-up, we recorded epilepsy in ¼ of patients.

The risk of epilepsy after neonatal seizures

AIM

To estimate the cumulative risk of epilepsy after neonatal seizures and identify subpopulations at increased risk.

METHOD

This was a nationwide register-based cohort study including all children born in Denmark between 1997 and 2018. The cumulative risk of epilepsy in children with and without neonatal seizures was compared. Furthermore, neonatal seizures were stratified according to aetiology.

RESULTS

We followed 1 294 377 children and identified 1998 neonatal survivors with neonatal seizures. The cumulative risk of epilepsy was 20.4% (95% confidence interval [CI] = 18.5-22.3) among children with neonatal seizures, compared to 1.15% (95% CI = 1.12-1.18) among children without. Epilepsy was diagnosed before 1 year of age in 11.4% of children with neonatal seizures, in an additional 4.5% between 1 year and 5 years, 3.1% between 5 years and 10 years, and 1.4% between 10 years and 22 years. The aetiologies of neonatal cerebral infarction, haemorrhage, or malformations (adjusted hazard ratio = 2.49, 95% CI = 1.98-3.14) and low Apgar score (1.49, 95% CI = 1.12-1.98) were associated with the highest risk of epilepsy, compared to children with seizures of unknown aetiology.

INTERPRETATION

Epilepsy after neonatal seizures is common and remains a substantial risk throughout childhood. Aetiological risk factors are identifiable and relevant when planning appropriate information for parents and follow-up.

Defining neonatal status epilepticus: A scoping review from the ILAE neonatal task force

OBJECTIVE

To review the available literature concerning the definition of neonatal status epilepticus (SE) and/or seizure burden.

METHODS

The International League Against Epilepsy Neonatal Task Force performed a scoping review of the definitions of neonatal SE. Following a systematic literature review, articles were screened and data were abstracted regarding: (1) article characteristics (author identification, publication year, journal name, digital object identifier, title, objective, and study design); (2) cohort characteristics (sample size, gestational age, seizure etiology); (3) definition of SE and/or seizure burden; and (4) the method used to identify and classify SE, including routine EEG (EEG), continuous EEG monitoring (cEEG), amplitude-integrated EEG (aEEG), or clinical features.

RESULTS

The scoping review yielded 44 articles containing a definition of neonatal SE. Studies mainly included infants with hypoxic-ischemic encephalopathy or neonates considered at risk for seizures. SE identification and classification most often relied on cEEG. The majority of studies based the definition of SE on seizure duration, including summed duration of seizures comprising ≥50% of any 1-h epoch, recurrent seizures for >50% of the total recording time, or either electrographic seizures lasting >30 min and/or repeated electrographic seizures totaling >50% in any 1-h period. Seizure burden was reported in 20 studies, and the most commonly used approach assessed total seizure burden, defined as total duration of EEG seizures in minutes. Sixteen studies assessed the relationship between seizure burden and outcomes, and most identified a significant association between higher seizure burden and unfavorable outcomes.

SIGNIFICANCE

This scoping review demonstrates a substantial variation in neonatal SE definitions across the literature. The most common definitions were based around a 30-min seizure duration criterion, but evidence was insufficient to support that 30 min was a cutoff defining prolonged seizures or that seizures exceeding this burden were more likely to be pharmacoresistant or associated with worse outcomes. As a next step, the Neonatal Task Force intends to develop a standardized approach to assessing and describing neonatal seizure burden and defining neonatal SE.

PLAIN LANGUAGE SUMMARY

Prolonged seizures are a neurologic emergency, if untreated, can lead to permanent injury or death. In adults and children, seizures lasting longer than 30 min are believed to cause brain damage. However, it is not clear if this definition can be applied to neonates. The International League Against Epilepsy Neonatal Taskforce performed a scoping literature review which identified 44 articles containing a definition of neonatal status epilepticus. In this article, the authors reviewed the current used definitions for prolonged seizures in neonates to establish a relationship between seizure duration and neurological outcome. As a next step, the Neonatal Task Force intends to develop a standardized approach to assessing and describing neonatal seizure burden and defining neonatal SE.

Temporal development of seizure threshold and spontaneous seizures after neonatal asphyxia and the effect of prophylactic treatment with midazolam in rats

Birth asphyxia (BA) and subsequent hypoxic-ischemic encephalopathy (HIE) is one of the most serious birth complications affecting full-term infants and can result in severe disabilities including mental retardation, cerebral palsy, and epilepsy. Animal models of BA and HIE are important to characterize the functional and behavioral correlates of injury, explore cellular and molecular mechanisms, and assess the potential of novel therapeutic strategies. Here we used a non-invasive, physiologically validated rat model of BA and acute neonatal seizures that mimics many features of BA and HIE in human infants to study (i) the temporal development of epilepsy with spontaneous recurrent seizures (SRS) in the weeks and months after the initial brain injury, (ii) alterations in seizure threshold and hippocampal EEG that may precede the onset of SRS, and (iii) the effect of prophylactic treatment with midazolam. For this purpose, a total of 89 rat pups underwent asphyxia or sham asphyxia at postnatal day 11 and were examined over 8-10.5 months. In vehicle-treated animals, the incidence of electroclinical SRS progressively increased from 0 % at 2.5 months to 50 % at 6.5 months, 75 % at 8.5 months, and > 80 % at 10.5 months after asphyxia. Unexpectedly, post-asphyxial rats did not differ from sham-exposed rats in seizure threshold or interictal epileptiform discharges in the EEG. Treatment with midazolam (1 mg/kg i.p.) after asphyxia, which suppressed acute symptomatic neonatal seizures in about 60 % of the rat pups, significantly reduced the incidence of SRS regardless of its effect on neonatal seizures. This antiepileptogenic effect of midazolam adds to the recently reported prophylactic effects of this drug on BA-induced neuroinflammation, brain damage, behavioral alterations, and cognitive impairment in the rat asphyxia model of HIE.

Reducing the percentage of surviving infants with acute symptomatic seizures discharged on anti-seizure medication

OBJECTIVE

To evaluate the impact of inclusion of an anti-seizure medication (ASM) weaning protocol in a neonatal seizure pathway on the percent of infants discharged on ASMs.

STUDY DESIGN

This cohort study included surviving infants with acute symptomatic seizures treated with ASMs across three institutions. We evaluated infants in 2 epochs, pre- and post-implementation of the ASM weaning protocol. The primary outcome was discharge on ASM.

RESULTS

Of 116 included infants, the percent of infants discharged on ASMs was 69% in epoch 1 versus 34% in epoch 2 (p < 0.001). There was no significant difference between epochs in recurrence of seizures after discharge by 1 year of age (p = 0.125). There was an annual decrease in the percent of infants discharged on ASM across all institutions.

CONCLUSION

Inclusion of a formal ASM weaning protocol as part of an institutional seizure pathway reduced percent of infants with acute symptomatic seizures discharged on ASM.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSION

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

Neurodevelopmental outcome of neonatal seizures: A longitudinal study

INTRODUCTION

Neonatal seizures (NS) are the most common neurological emergency in the neonatal period. The International League Against Epilepsy (ILAE) proposed a new classification of NS based on semiology and highlighted the correlation between semiology and aetiology. However, neurodevelopmental outcomes have not been comprehensively evaluated based on this new classification.

AIMS

To evaluate neurodevelopmental outcomes and potential risk factors for severe outcomes in NS.

METHODS

Patients with video electroencephalogram confirmed NS were evaluated. Seizure aetiology, cerebral magnetic resonance imaging (MRI) data, background electroencephalograms data, general movements, and neurodevelopmental outcomes were analysed. Severe outcomes were one of the following: death, cerebral palsy, Griffiths developmental quotient <70, epilepsy, deafness, or blindness.

RESULTS

A total of 74 neonates were evaluated: 62 (83.8 %) with acute provoked NS (primarily hypoxic-ischaemic encephalopathy), and 12 (16.2 %) with neonatal-onset epilepsies (self-limited neonatal epilepsy, developmental and epileptic encephalopathy, cerebral malformations). Of these, 32 (43.2 %) had electrographic seizures, while 42 (56.7 %) had electroclinical seizures - 38 (90.5 %) were motor (42.1 % clonic) and 4 (9.5 %) were non-motor phenomena. Severe outcomes occurred in 33 of the 74 (44.6 %) participants. In multivariate analysis, neonatal-onset epilepsies (odds ratio [OR]: 1.3; 95 % confidence interval [CI]: 1.1-1.6), status epilepticus (OR: 5.4; 95 % CI: 1.5-19.9), and abnormal general movements (OR: 3.4; 95 % CI: 1.9-7.6) were associated with severe outcomes.

CONCLUSIONS

At present, hypoxic-ischaemic encephalopathy remains the most frequent aetiology of NS. The prognosis of neonatal-onset epilepsies was worse than that of acute provoked NS, and status epilepticus was the most predictive factor for adverse outcomes.

Acute symptomatic seizures in newborns: a narrative review

Acute symptomatic seizures are the main sign of neurological dysfunction in newborns. This is linked to the unique characteristics of the neonatal brain, making it hyperexcitable compared to older ages, and to the common occurrence of some forms of acquired brain injury, namely hypoxic-ischemic encephalopathy. In this narrative review we will provide an overview of neonatal seizures definition, their main underlying etiologies, diagnostic work-up and differential diagnoses, and will discuss about therapeutic options and prognostic outlook. The latest publications from the ILAE Task Force on Neonatal Seizures will be presented and discussed. Of note, they highlight the current lack of robust evidence in this field of clinical neurology. We will also report on specificities pertaining to low-and-middle income countries in terms of incidence, main etiologies and diagnosis. The possibilities offered by telemedicine and automated seizures detection will also be summarized in order to provide a framework for future directions in seizures diagnosis and management with a global perspective. Many challenges and opportunities for improving identification, monitoring and treatment of acute symptomatic seizures in newborns exist. All current caveats potentially represent different lines of research with the aim to provide better care and reach a deeper understanding of this important topic of neonatal neurology.

Effects of season, daytime, sex, and stress on the incidence, latency, frequency, severity, and duration of neonatal seizures in a rat model of birth asphyxia

Neonatal seizures are common in newborn infants after birth asphyxia. They occur more frequently in male than female neonates, but it is not known whether sex also affects seizure severity or duration. Furthermore, although stress and diurnal, ultradian, circadian, or multidien cycles are known to affect epileptic seizures in adults, their potential impact on neonatal seizures is not understood. This prompted us to examine the effects of season, daytime, sex, and stress on neonatal seizures in a rat model of birth asphyxia. Seizures monitored in 176 rat pups exposed to asphyxia on 40 experimental days performed over 3 years were evaluated. All rat pups exhibited seizures when exposed to asphyxia at postnatal day 11 (P11), which in terms of cortical development corresponds to term human babies. A first examination of these data indicated a seasonal variation, with the highest seizure severity in the spring. Sex and daytime did not affect seizure characteristics. However, when rat pups were subdivided into animals that were exposed to acute (short-term) stress after asphyxia (restraint and i.p. injection of vehicle) and animals that were not exposed to this stress, the seizures in stress-exposed rats were more severe but less frequent. Acute stress induced an increase in hippocampal microglia density in sham-exposed rat pups, which may have an additive effect on microglia activation induced by asphyxia. When seasonal data were separately analyzed for stress-exposed vs. non-stress-exposed rat pups, no significant seasonal variation was observed. This study illustrates that without a detailed analysis of all factors, the data would have erroneously indicated significant seasonal variability in the severity of neonatal seizures. Instead, the study demonstrates that even mild, short-lasting postnatal stress has a profound effect on asphyxia-induced seizures, most likely by increasing the activity of the hypothalamic-pituitary-adrenal axis. It will be interesting to examine how postnatal stress affects the treatment and adverse outcomes of birth asphyxia and neonatal seizures in the rat model used here.

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.

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.

The loop diuretic torasemide but not azosemide potentiates the anti-seizure and disease-modifying effects of midazolam in a rat model of birth asphyxia

Loop diuretics such as furosemide and bumetanide, which act by inhibiting the Na-K-2Cl cotransporter NKCC2 at the thick ascending limb of the loop of Henle, have been shown to exert anti-seizure effects. However, the exact mechanism of this effect is not known. For bumetanide, it has been suggested that inhibition of the NKCC isoform NKCC1 in the membrane of brain neurons may be involved; however, NKCC1 is expressed by virtually all cell types in the brain, which makes any specific targeting of neuronal NKCC1 by bumetanide impossible. In addition, bumetanide only poorly penetrates the brain. We have previously shown that loop diuretics azosemide and torasemide also potently inhibit NKCC1. In contrast to bumetanide and furosemide, azosemide and torasemide lack a carboxylic group, which should allow them to better penetrate through biomembranes by passive diffusion. Because of the urgent medical need to develop new treatments for neonatal seizures and their adverse outcome, we evaluated the effects of azosemide and torasemide, administered alone or in combination with phenobarbital or midazolam, in a rat model of birth asphyxia and neonatal seizures. Neither diuretic suppressed the seizures when administered alone but torasemide potentiated the anti-seizure effect of midazolam. Brain levels of torasemide were below those needed to inhibit NKCC1. In addition to suppressing seizures, the combination of torasemide and midazolam, but not midazolam alone, prevented the cognitive impairment of the post-asphyxial rats at 3 months after asphyxia. Furthermore, aberrant mossy fiber sprouting in the hippocampus was more effectively prevented by the combination. We assume that either an effect on NKCC1 at the blood-brain barrier and/or cells in the periphery or the NKCC2-mediated diuretic effect of torasemide are involved in the present findings. Our data suggest that torasemide may be a useful option for improving the treatment of neonatal seizures and their adverse outcome.

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

Introduction

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

Methods

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

Results

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

Discussion

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

Prevalence, Risk Factors, and Impact of Preoperative Seizures in Neonates With Congenital Heart Disease

PURPOSE

The purpose of this study was to assess the prevalence, risk factors, and impact of electrographic seizures in neonates with complex congenital heart disease before cardiac surgery.

METHODS

A cohort of 31 neonates with congenital heart disease monitored preoperatively with continuous video-EEG (cEEG) was first reviewed for electrographic seizure burden and EEG background abnormalities. Second, cEEG findings were correlated with brain MRI and 18-month outcomes.

RESULTS

Continuous video-EEG was recorded preoperatively for a median duration of 20.5 hours (range, 2.5-93.5 hours). The five neonates (16%; 95% confidence interval, 5.5% to 34%) with seizures detected on cEEG in the preoperative period had a diagnosis of transposition of the great arteries or similar physiology, detected in four of five postnatally. None of the 157 recorded electrographic seizures had a clinical correlate. The median time to first seizure was 65 minutes (range, 6-300 minutes) after cEEG hookup. The median maximum hourly seizure burden was 12.4 minutes (range, 7-23 minutes). Before the first electrographic seizure, a prolonged interburst interval (>10 seconds) was not associated with seizures (coefficient 1.2; 95% confidence interval, -1.1 to 3.6). MRI brain lesions were three times more common in neonates with seizures. Sharp wave transients on cEEG were associated with delayed opercular development.

CONCLUSIONS

In this cohort, preoperative electrographic seizures were common, were all subclinical, and were associated with MRI brain injury and postnatal diagnosis of transposition of the great arteries. The findings motivate further study of the mechanisms of preoperative brain injury, particularly among neonates with a postnatal diagnosis of transposition of the great arteries.

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.

Sleep architecture in neonatal and infantile onset epilepsies in the first six months of life: A scoping review

AIM

Epilepsy occurs in approximately 80 per 100,000 infants in the first year of life, ranging in severity from self-limited and likely to spontaneously resolve, to severe developmental and epileptic encephalopathies. Sleep plays a key role in early brain development and the reciprocal relationship between sleep and seizures is not yet fully understood, particularly in young children. We conducted a Scoping Review to synthesise current knowledge of sleep architecture in neonates and infants with epilepsy.

METHOD

Peer-reviewed publications from 2005 to 2022 describing sleep architecture in infants up to six months of age with unprovoked seizures were included. The analysis set was derived from EMBASE, Web of Science and PubMED using key terms "sleep, epilepsy and infant" and related descriptors. Inclusion criteria were prospectively described in a Scoping Review protocol. Sleep architecture was assessed as macro- and micro-structural elements.

RESULTS

21 publications were included in the qualitative analysis. In self-limited familial and genetic epilepsy, sleep macrostructure was generally preserved. In DEEs and in epileptic encephalopathies of genetic or structural aetiology, sleep architecture was significantly disrupted.

INTERPRETATION

Early identification of infants with epilepsy is important to ensure early and effective treatment. In the DEE spectrum, sleep architecture is significantly impacted, and abnormal sleep architecture may be associated with compromised developmental outcome. Further research is needed to identify the sequence of events in abnormal brain development, epilepsy and sleep disruption and potentially help to predict the course of epilepsy towards a self-limited epilepsy versus a DEE.

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.

aEEG vs cEEG's sensivity for seizure detection in the setting of neonatal intensive care units: A systematic review and meta-analysis

AIM

Amplitude-integrated electroencephalography (aEEG)'s accuracy compared to conventional electroencephalography (cEEG) has not been fully established. The aim of our study was to conduct a systematic review on the sensitivity of the aEEG for neonatal seizure detection.

METHODS

Studies from PubMed and Google Scholar databases comparing recordings of cEEG and aEEG in newborns were included according to the PRISMA method. A quality assessment using the QUADAS-2 tool was provided. A random-effect model was used to account for different sources of variations among studies. Publication biases were represented by a funnel plot, and funnel plot symmetry was assessed.

RESULTS

Fourteen studies were reported; sensitivity of each diagnostic tool used (single-channel aEEG, two-channel aEEG, two-channel aEEG plus raw trace EEG) was compared to that of the gold-standard cEEG and to those of the other methods used. Overall sensitivity of the aEEG ranged from 31.25% to 90%.

CONCLUSION

Our study provides evidence that sensitivity of aEEG varies significantly and that seizure detection rate is lower than that of cEEG. The two-channel aEEG with raw trace EEG shows a high sensitivity and might represent a valid alternative to the cEEG in the setting of neonatal intensive care units (NICUs).

Case Report: Early Neonatal EEG in Two Infants with Pallister Killian Syndrome (PKS)

Pallister Killian Syndrome (PKS) is a rare genetic disorder caused by a mosaic tetrasomy of the short arm of chromosome 12. The syndrome is characterised by typical craniofacial dysmorphism, congenital anomalies and intellectual disability. Epilepsy is a known complication, with onset usually occurring in early childhood and characterised most commonly by spasms and myoclonic seizures. To the best of our knowledge, there have been no cases describing the early neonatal EEG in PKS and  electrographic seizures, to date. Here, we report two cases of PKS presenting in the neonatal period with distinctive EEG features and seizures.

Expert consensus on grading management of electroencephalogram monitoring in neonates

Neonatal electroencephalogram (EEG) monitoring guidelines have been published by American Clinical Neurophysiology Society, and the expert consensus on neonatal amplitude-integrated EEG (aEEG) has also been published in China. It is difficult to strictly follow the guidelines or consensus for EEG monitoring in different levels of neonatal units due to a lack of EEG monitoring equipment and professional interpreters. The Subspecialty Group of Neonatology, Society of Pediatrics, Chinese Medical Association, established an expert group composed of professionals in neonatology, pediatric neurology, and brain electrophysiology to review published guidelines and consensuses and the articles in related fields and propose grading management recommendations for EEG monitoring in different levels of neonatal units. Based on the characteristics of video EEG and aEEG, local medical resources, and disease features, the expert group recommends that video EEG and aEEG can complement each other and can be used in different levels of neonatal units. The consensus also gives recommendations for promoting collaboration between professionals in neonatology, pediatric neurology, and brain electrophysiology and implementing remote EEG monitoring.

Long-term outcome in a noninvasive rat model of birth asphyxia with neonatal seizures: Cognitive impairment, anxiety, epilepsy, and structural brain alterations

OBJECTIVE

Birth asphyxia is a major cause of hypoxic-ischemic encephalopathy (HIE) in neonates and often associated with mortality, neonatal seizures, brain damage, and later life motor, cognitive, and behavioral impairments and epilepsy. Preclinical studies on rodent models are needed to develop more effective therapies for preventing HIE and its consequences. Thus far, the most popular rodent models have used either exposure of intact animals to hypoxia-only, or a combination of hypoxia and carotid occlusion, for the induction of neonatal seizures and adverse outcomes. However, such models lack systemic hypercapnia, which is a fundamental constituent of birth asphyxia with major effects on neuronal excitability. Here, we use a recently developed noninvasive rat model of birth asphyxia with subsequent neonatal seizures to study later life adverse outcome.

METHODS

Intermittent asphyxia was induced for 30 min by exposing male and female postnatal day 11 rat pups to three 7 + 3-min cycles of 9% and 5% O₂ at constant 20% CO₂ . All pups exhibited convulsive seizures after asphyxia. A set of behavioral tests were performed systematically over 14 months following asphyxia, that is, a large part of the rat's life span. Video-electroencephalographic (EEG) monitoring was used to determine whether asphyxia led to the development of epilepsy. Finally, structural brain alterations were examined.

RESULTS

The animals showed impaired spatial learning and memory and increased anxiety when tested at an age of 3-14 months. Video-EEG at ~10 months showed an abundance of spontaneous seizures, which was paralleled by neurodegeneration in the hippocampus and thalamus, and by aberrant mossy fiber sprouting.

SIGNIFICANCE

The present model of birth asphyxia recapitulates several of the later life consequences associated with human HIE. This model thus allows evaluation of the efficacy of novel therapies designed to prevent HIE and seizures following asphyxia, and of how such therapies might alleviate long-term adverse consequences.

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.

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.

Treating the symptom or treating the disease in neonatal seizures: a systematic review of the literature

Aim

The existing treatment options for neonatal seizures have expanded over the last few decades, but no consensus has been reached regarding the optimal therapeutic protocols. We systematically reviewed the available literature examining neonatal seizure treatments to clarify which drugs are the most effective for the treatment of specific neurologic disorders in newborns.

Method

We reviewed all available, published, literature, identified using PubMed (published between August 1949 and November 2020), that focused on the pharmacological treatment of electroencephalogram (EEG)-confirmed neonatal seizures.

Results

Our search identified 427 articles, of which 67 were included in this review. Current knowledge allowed us to highlight the good clinical and electrographic responses of genetic early-onset epilepsies to sodium channel blockers and the overall good response to levetiracetam, whose administration has also been demonstrated to be safe in both full-term and preterm newborns.

Interpretation

Our work contributes by confirming the limited availability of evidence that can be used to guide the use of anticonvulsants to treat newborns in clinical practice and examining the efficacy and potentially harmful side effects of currently available drugs when used to treat the developing newborn brain; therefore, our work might also serve as a clinical reference for future studies.

Neonatal Seizures and Future Epilepsy: Predictive Value of Perinatal Risk Factors, Electroencephalography, and Imaging

Context

There are limited data in the literature about the relationship between neonatal seizures and subsequent epilepsy.

Aims

This study aimed to identify the predictive value of perinatal factors, etiologies, electroencephalography (EEG), and cranial ultrasonography (USG) for future epilepsy after neonatal seizures.

Materials and Methods

A total of 92 children with epilepsy who had seizures during their neonatal period were retrospectively evaluated whether the contribution of perinatal, natal, and postnatal risk factors confining clinical, laboratory, EEG, and imaging to subsequent epilepsy. Chi-square, uni, and multivariate logistic regression were applied to find out predictive factors for subsequent epilepsy.

Results

The rate of epilepsy was 57.6 % during 1-6 years follow-up. Birth weight, Apgar scores at first and fifth minutes, resuscitation history, abnormal neurological examination, etiology, response to the treatment, abnormal EEG, or USG findings were the most important risk factors for future epilepsy in univariate analysis (P < 0.05). Furthermore, asphyxia, fifth minute Apgar scores, response to the treatment, USG, and EEG were independent predictors (P < 0.05) for subsequent epilepsy in multivariate logistic regression. No relationship was found between subsequent epilepsy and mode of delivery, seizure onset time, and seizure types (P > 0.05).

Conclusion

Although there are recent promising and advanced techniques in neonatal intensive care units, asphyxia is still one of the most important risk factors for not only poor neurological conditions but also for future epilepsy after neonatal seizures. Apgar scores, treatment with multiple antiepileptic drugs, poor background EEG activity, and abnormal neuroimaging seem to have strong predictive values for developing subsequent epilepsy. Therefore, patients with a history of neonatal seizures should be closely followed up to decrease the risk of long-term outcomes and early detection of epilepsy.

Consensus protocol for EEG and amplitude-integrated EEG assessment and monitoring in neonates

The aim of this work is to establish inclusive guidelines on electroencephalography (EEG) applicable to all neonatal intensive care units (NICUs). Guidelines on ideal EEG monitoring for neonates are available, but there are significant barriers to their implementation in many centres around the world. These include barriers due to limited resources regarding the availability of equipment and technical and interpretive round-the-clock personnel. On the other hand, despite its limitations, amplitude-integrated EEG (aEEG) (previously called Cerebral Function Monitor [CFM]) is a common alternative used in NICUs. The Italian Neonatal Seizure Collaborative Network (INNESCO), working with all national scientific societies interested in the field of neonatal clinical neurophysiology, performed a systematic literature review and promoted interdisciplinary discussions among experts (neonatologists, paediatric neurologists, neurophysiologists, technicians) between 2017 and 2020 with the aim of elaborating shared recommendations. A consensus statement on videoEEG (vEEG) and aEEG for the principal neonatal indications was established. The authors propose a flexible frame of recommendations based on the complementary use of vEEG and aEEG applicable to the various neonatal units with different levels of complexity according to local resources and specific patient features. Suggestions for promoting cooperation between neonatologists, paediatric neurologists, and neurophysiologists, organisational restructuring, and teleneurophysiology implementation are provided.

Models for predicting treatment efficacy of antiepileptic drugs and prognosis of treatment withdrawal in epilepsy patients

Although antiepileptic drugs (AEDs) are the most effective treatment for epilepsy, 30–40% of patients with epilepsy would develop drug-refractory epilepsy. An accurate, preliminary prediction of the efficacy of AEDs has great clinical significance for patient treatment and prognosis. Some studies have developed statistical models and machine-learning algorithms (MLAs) to predict the efficacy of AEDs treatment and the progression of disease after treatment withdrawal, in order to provide assistance for making clinical decisions in the aim of precise, personalized treatment. The field of prediction models with statistical models and MLAs is attracting growing interest and is developing rapidly. What’s more, more and more studies focus on the external validation of the existing model. In this review, we will give a brief overview of recent developments in this discipline.

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.

A critical analysis of the purported role of hypoxaemia in the comorbidity of obstructive sleep apnoea and epilepsy

Obstructive sleep apnoea (OSA) is a globally prevalent sleep disorder of significant health concern and confounded with several comorbidities resulting in adverse effect(s) on quality of life in patients afflicted with it. Of particular interest is the enigmatic high comorbidity of OSA with epilepsy, the exact underlying pathophysiology of which remains elusive despite a multitude of research performed in the last four decades. Hypoxaemia, which is an important characteristic feature found in OSA during apnoeic spells, has been implicated in the high comorbidity of OSA with epilepsy, the basis of which rests upon hypoxaemia-mediated brain damage, subcortical release phenomenon, oxidative stress and neuroinflammatory reactions. However, several studies present contradictory evidences that potentially refute the hypoxaemia-based mechanism. Additionally, the role of hypercapnia thatgenerally accompanies hypoxaemia during apnoeic spells, cannot be overlooked and is known to be potentially protective against neuronal hyperexcitability. Thus, hypoxaemia theory implicated in the high comorbidity of OSA and epilepsy appears weak and refutable. This brief paper studies and critically analyses the role of hypoxaemia in conjunction with hypercapnia in the underlying pathophysiology of the comorbidity.

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.

Efficacy of Levetiracetam in neonatal seizures: a systematic review

BACKGROUND

Neonatal seizures represent the most frequent presenting sign of any neurological abnormality secondary to various etiologies in the neonatal period. Phenobarbitone (PB) has been used as first-line anti-epileptic drug in the treatment of seizures but concerns have been raised regarding its neuro-apoptotic effects over the developing brain. Levetiracetam (LEV) is a newer anti-epileptic drug with neuroprotective property and has been used in adults and pediatric patient but its use in neonates have very limited experience. Recently many neonatal studies have sought the role of LEV in the management of neonatal seizures.

AIMS AND OBJECTIVE

To evaluate the efficacy of Levetiracetam in the management of neonatal seizures.

SEARCH METHODS

The literature search was done for this systematic review by searching the Cochrane Central Register of Controlled Trials (CENTRAL), and other various electronic databases including PubMed and various sites for ongoing trials and abstracts of conferences.

RESULTS

Two eligible studies were analyzed that fulfilled the inclusion criteria of the systematic review. Fifteen studies were excluded due to the non-fulfillment of inclusion criteria. The primary outcome of both studies was to see the efficiency of LEV in controlling neonatal seizures when compared to PB. Better seizure control after a single loading dose of LEV was seen. Rates of seizure cessation at 24 h was also better in the LEV arm. Neonatal seizures secondary to hypoxic-ischemic encephalopathy (HIE) and receiving therapeutic hypothermia were better controlled with LEV. The side effect of LEV was significantly less when compared to PB.

CONCLUSION

Levetiracetam has shown to have promising anti-epileptic properties for the management of neonatal seizure with better efficacy and less or no side effects. There is a need to conduct more randomized controlled trials seeking the role of LEV in the acute management of neonatal seizures and also for assessing its neuroprotective role and neurodevelopmental outcome in these neonates.

Neonatal Seizures and Purinergic Signalling

Neonatal seizures are one of the most common comorbidities of neonatal encephalopathy, with seizures aggravating acute injury and clinical outcomes. Current treatment can control early life seizures; however, a high level of pharmacoresistance remains among infants, with increasing evidence suggesting current anti-seizure medication potentiating brain damage. This emphasises the need to develop safer therapeutic strategies with a different mechanism of action. The purinergic system, characterised by the use of adenosine triphosphate and its metabolites as signalling molecules, consists of the membrane-bound P1 and P2 purinoreceptors and proteins to modulate extracellular purine nucleotides and nucleoside levels. Targeting this system is proving successful at treating many disorders and diseases of the central nervous system, including epilepsy. Mounting evidence demonstrates that drugs targeting the purinergic system provide both convulsive and anticonvulsive effects. With components of the purinergic signalling system being widely expressed during brain development, emerging evidence suggests that purinergic signalling contributes to neonatal seizures. In this review, we first provide an overview on neonatal seizure pathology and purinergic signalling during brain development. We then describe in detail recent evidence demonstrating a role for purinergic signalling during neonatal seizures and discuss possible purine-based avenues for seizure suppression in neonates.

Risk factors for neonatal seizures: A case-control study in the province of Parma, Italy

PURPOSE

The present study evaluated the risk factors for electroencephalographic (EEG)-confirmed seizures during the whole neonatal period in preterm and term neonates born in the province of Parma between January 2009 and December 2014.

METHODS

We selected as cases the infants that presented EEG-confirmed neonatal seizures (NS). Two population controls for each case were matched by gestational age (GA), sex, hospital, and period of birth. Information on the mother, the pregnancy, the labor and delivery, and the neonates were taken from the Emilia-Romagna Certificate of Delivery Assistance database and from hospital charts and ICD-9-CM codes.

RESULTS AND INTERPRETATION

In the 6-year period of this study, 22 patients were recorded with NS. The association between at least one pregnancy complication and at least one neonatal complication, a low Apgar score, the need for resuscitation at birth, intraventricular hemorrhages (IVH) grades II-IV for preterm, and acute perinatal asphyxia/hypoxic-ischemic encephalopathy (HIE) for term infants were all statistically significant among cases. Neonates presenting these risk factors are more prone to develop NS and have to be strictly monitored.

Evaluation of the prognostic factors in school age children who experienced neonatal seizures

BACKGROUND

This prospective study aimed to evaluate long-term neurodevelopmental outcomes and risk factors of the previously reported cohort, at their school age.

METHOD

We included neonates whose seizures were directly observed by the child neurologist or neonatologist based on clinical observations. They were assessed for cognitive and neurological outcomes at the age of 9-11 years. The test battery included a neurological examination, the Wechsler Intelligence Scale for Children-Revised (WISC-R) test, and patients with the diagnosis of cerebral palsy (CP) were graded according to the Gross Motor Function Classification System (GMFCS). The primary outcome of this study was to determine risk factors for the long-term prognosis of neonatal seizures.

RESULTS

For the long-term follow-up, 97 out of 112 patients of the initial cohort were available (86.6%). We found that 40 patients (41%) have the normal prognosis, 22 patients (22.7%) have the diagnosis of CP, and 30 patients (30.9%) were diagnosed as having epilepsy. Twelve out of 22 patients with CP had the diagnosis of epilepsy. The WISC-R full-scale IQ scores were <55 points in 27 patients (27.8%) and were >85 points in 40 patients (41.2%). According to GMFCS, 10 patients were classified as levels 1-2, and 12 patients were classified as levels 3-5. In multivariate regression analyses, 5-min APGAR score <6 was found to be an independent risk factor for CP, and 5-min APGAR score <6 and neonatal status epilepticus were independent risk factors for epilepsy.

CONCLUSIONS

This prospective cohort study reveals that abnormal school age outcome after neonatal seizures are significantly related to 5-min APGAR score <6 and neonatal status epilepticus.

Neonatal seizures in preterm infants: A systematic review of mortality risk and neurological outcomes from studies in the 2000's

INTRODUCTION

Neonatal seizures (NS) are associated with increased mortality and risk of cerebral palsy, epilepsy and intellectual disability. We performed a systematic review with the primary objective to delineate the rate of these outcomes following NS in preterm infants from studies published in the 2000's and the secondary objective to identify risk factors.

METHODS

Inclusion criteria: original articles published between 1/1/2000 and 12/31/2018, written in English, evaluating newborns ≤37 weeks of gestational age and suffering from NS, in which at least one of these was evaluated: epilepsy, cerebral palsy, intellectual disability/developmental delay, normal outcome, death.

RESULTS

Twenty-two papers were selected and all were observational, with a retrospective design in 15. Three were population-based and twenty-one have a comparison. It has been found a 22-80 % of mortality, 11.3-38.9 % of epilepsy, 12-84.6 % of cerebral palsy, and 20-42.7 % of intellectual disability/developmental delay rate. An increased risk for all outcomes considered was reported. Risk factors for specific outcomes were provided by a minority of studies. However, inclusion criteria, definition of NS and measured outcomes, follow-up lengths differed considerably between studies.

DISCUSSION

Results of the selected studies are only partially comparable or generalizable because of differences in study design. They have a risk for potential biases, although they provide (if analyzed) readily available prognostic factors, easy to apply in clinical practice. Prospective, population-based studies with EEG-defined NS are warranted in order to produce evidence-based guidance for management of preterm newborns with seizures.

Why we urgently need improved seizure and epilepsy therapies for children and neonates

In contrast to epilepsy in adolescents and adults, neonatal seizures and early onset epilepsy poses unique challenges with significant repercussion for treatment choices. Most importantly, high seizure burden and epileptic encephalopathy are associated with developmental, behavioural and cognitive problems. The causes are multifactorial and include etiology, seizure burden, epileptic encephalopathy, but also antiseizure medication. In contrast to adults and older children only very few drugs have been licenced for infants and neonates, and after a long delay. Very recently, extrapolation of adult data has become possible as a path to speed up drug development for younger children but this is not necessarily possible for infants and neonates. With the advances in understanding the molecular basis of many epilepsies, targeted therapies become available, for example for KCNQ2 mutation related epilepsies, Dravet syndrome or tuberous sclerosis complex. Drug trials in neonates are particularly challenging because of their inconspicuous clinical presentation, the need for continuous EEG monitoring, high co-morbidity, and poor response to antiepileptic drugs. There is an urgent need for development of new drugs, evaluation of safety and efficacy of current antiseizure drugs, as well as for national policies and guidelines for the management of seizures and epilepsy in neonates and infants. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.

Early changes in pro-inflammatory cytokine levels in neonates with encephalopathy are associated with remote epilepsy

BACKGROUND

Neonatal seizures are associated with adverse neurologic sequelae including epilepsy in childhood. Here we aim to determine whether levels of cytokines in neonates with brain injury are associated with acute symptomatic seizures or remote epilepsy.

METHODS

This is a cohort study of term newborns with encephalopathy at UCSF between 10/1993 and 1/2000 who had dried blood spots. Maternal, perinatal/postnatal, neuroimaging, and epilepsy variables were abstracted by chart review. Logistic regression was used to compare levels of cytokines with acute seizures and the development of epilepsy.

RESULTS

In a cohort of 26 newborns with neonatal encephalopathy at risk for hypoxic ischemic encephalopathy with blood spots for analysis, diffuse alterations in both pro- and anti-inflammatory cytokine levels were observed between those with (11/28, 39%) and without acute symptomatic seizures. Seventeen of the 26 (63%) patients had >2 years of follow-up and 4/17 (24%) developed epilepsy. Higher levels of pro-inflammatory cytokines IL-6 and TNF-α within the IL-1β pathway were significantly associated with epilepsy.

CONCLUSIONS

Elevations in pro-inflammatory cytokines in the IL-1β pathway were associated with later onset of epilepsy. Larger cohort studies are needed to confirm the predictive value of these circulating biomarkers.

Efficacy and safety of levetiracetam in children with epilepsy: protocol for an umbrella review of systematic reviews and meta-analyses of randomised controlled trials

INTRODUCTION

Epilepsy causes serious suffering in children and is associated with high morbidity and increased mortality. It impairs children's quality of life and places a heavy burden on healthcare resources. Levetiracetam has been used to prevent and treat paediatric epilepsy for years. To date, a number of systematic reviews have been performed to assess the efficacy and safety of levetiracetam in a variety of clinical settings. Conflicting outcomes have been reported for the same clinical issues. Our objective is to provide a comprehensive overview of the literature for clinicians and policymakers via an umbrella review that assesses the efficacy and safety of levetiracetam in children with epilepsy.

METHODS AND ANALYSIS

We will follow the Joanna Briggs Institute's guidelines for umbrella reviews and the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. The following seven databases will be searched from 1990 to February 2019: PubMed, Embase, Cochrane Database of Systematic Reviews, JBISRIR, EPPI, Epistemonikos and PROSPERO. We will provide evidence from existing systematic reviews and meta-analyses of randomised controlled trials regarding the use of levetiracetam in children with epilepsy. The intervention of interest is levetiracetam monotherapy and add-on therapies for prevention or treatment purposes. Studies will be individually selected and assessed by two reviewers. The primary outcomes of interest are epilepsy control, the efficacy of prophylaxis for provoked seizures and the mortality rate of children with epilepsy who received levetiracetam treatment. The secondary outcomes are adverse events and withdrawal rates due to adverse effects. The methodological quality of all reviews will be individually assessed by two reviewers using the 'A Measurement Tool to Assess Systematic Reviews' instrument. The Grading of Recommendations Assessment, Development and Evaluation assessment will be applied to evaluate the quality of evidence for each outcome of interest. A narrative description of an analysis of the systematic reviews will be tabulated to address objective and specific questions. Information from each review will be detailed in a table including the population, number of studies, total number of participants, year range of the trials, study designs of the primary trials, countries and settings of the trials, heterogeneity of results and assessment tools. Recommendations regarding each outcome of levetiracetam will be categorised based on a protocol.

ETHICS AND DISSEMINATION

This umbrella review will inform clinical and policy decisions regarding the efficacy and safety of levetiracetam for preventing and treating paediatric epilepsy. The results will be disseminated through a peer-reviewed publication and conference presentations. Ethical approval is not required for this study.

Etiology of neonatal seizures and maintenance therapy use: a 10-year retrospective study at Toulouse Children's hospital

BACKGROUND

No guidelines exist concerning the maintenance antiepileptic drug to use after neonatal seizures. Practices vary from one hospital to another. The aim of this study was to investigate etiologies and to report on the use of maintenance antiepileptic therapy in our population of full-term neonates presenting neonatal seizures.

METHODS

From January 2004 to October 2014, we retrospectively collected data from all full-term neonates with neonatal seizures admitted to the Children's Hospital of Toulouse, France.

RESULTS

Two hundred and forty-three neonates were included (59% males, 48% electroencephalographic confirmation). The frequencies of etiologies of neonatal seizures were: hypoxic-ischemic encephalopathy (HIE) (n = 91; 37%), ischemic infarction (n = 36; 15%), intracranial hemorrhage (n = 29; 12%), intracranial infection (n = 19; 8%), metabolic or electrolyte disorders (n = 9; 3%), inborn errors of metabolism (n = 5; 2%), congenital malformations of the central nervous system (n = 11; 5%), epileptic syndromes (n = 27; 12%) and unknown (n = 16; 7%). A maintenance therapy was prescribed in 180 (72%) newborns: valproic acid (n = 123), carbamazepine (n = 28), levetiracetam (n = 17), vigabatrin (n = 2), and phenobarbital (n = 4). In our cohort, the choice of antiepileptic drug depended mainly on etiology. The average duration of treatment was six months.

CONCLUSIONS

In our cohort, valproic acid was the most frequently prescribed maintenance antiepileptic therapy. However, the arrival on the market of new antiepileptic drugs and a better understanding of the physiopathology of genetic encephalopathies is changing our practice.

TRIAL REGISTRATION

Retrospectively registered. Patient data were reported to the "Commission Nationale Informatique et Libertés" under the number 2106953 .

Seizure Susceptibility Correlates with Brain Injury in Male Mice Treated with Hypothermia after Neonatal Hypoxia-Ischemia

Hypoxic-ischemic encephalopathy is a common neonatal brain injury associated with significant morbidity and mortality despite the administration of therapeutic hypothermia (TH). Neonatal seizures and subsequent chronic epilepsy are frequent in this patient population and current treatments are partially effective. We used a neonatal murine hypoxia-ischemia (HI) model to test whether the severity of hippocampal and cortical injury predicts seizure susceptibility 8 days after HI and whether TH mitigates this susceptibility. HI at postnatal day 10 (P10) caused hippocampal injury not mitigated by TH in male or female pups. TH did not confer protection against flurothyl seizure susceptibility at P18 in this model. Hippocampal (R2 = 0.33, p = 0.001) and cortical (R2 = 0.33, p = 0.003) injury directly correlated with seizure susceptibility in male but not female pups. Thus, there are sex-specific consequences of neonatal HI on flurothyl seizure susceptibility in a murine neonatal HI model. Further studies are necessary to elucidate the underlying mechanisms of sex dimorphism in seizure susceptibility after neonatal HI.

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.

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.

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.

Brain cooling reduces the risk of postneonatal epilepsy in newborns affected by moderate to severe hypoxic-ischemic encephalopathy

BACKGROUND

Neonatal hypoxic-ischemic encephalopathy is still a significant cause of neonatal death and neurodevelopmental disabilities, such as cerebral palsy, mental delay, and epilepsy. After the introduction of therapeutic hypothermia, the prognosis of hypoxic-ischemic encephalopathy has improved, with reduction of death and disabilities. However, few studies evaluated whether hypothermia affects rate and severity of postneonatal epilepsy. We evaluated rates, characteristics and prognostic markers of postneonatal epilepsy in infants with moderate to severe hypoxic-ischemic encephalopathy treated or not with therapeutic hypothermia.

METHODS

We analyzed clinical data, EEG recordings, cerebral Magnetic Resonance Imaging (MRI) and outcome in 23 cooled and 26 non-cooled asphyxiated neonates (≥36 weeks' gestation), admitted from 2004 to 2012.

RESULTS

Among 49 neonates 11 (22%) had postneonatal epilepsy, of which 9 (18%) were non-cooled and 2 (4%) were cooled (P=0.05). Six of 11 infants (55%) had West syndrome, 4 (36%) had focal epilepsy and 1 (9%) had Lennox-Gastaut Syndrome. At multiple logistic regression analysis MRI pattern significantly correlated with postneonatal epilepsy (OR 0.19, 95% CI 0.04-0.88, P=0.03). Extensive lesions in basal ganglia and thalami plus cortical and white matter were associated with postneonatal epilepsy.

CONCLUSIONS

Only perinatal asphyxia with extensive lesions in basal ganglia and thalami plus cortical and white matter lesion conveys a high risk for early and severe postneonatal epilepsy. Moreover, therapeutic hypothermia is associated with a decrease of the risk of developing postneonatal epilepsy.