Postneonatal epilepsy following amplitude-integrated EEG-detected neonatal seizures

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

AIM

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

METHODS

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

RESULTS

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

CONCLUSION

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

Epilepsy Frequency and Risk Factors Three Years After Neonatal Seizures

BACKGROUND

Neonatal seizures, one of the main risk factors for the development of epilepsy, remain a clinical concern. In children with neonatal seizures, early recognition of risk factors is important for the early diagnosis and appropriate treatment of epilepsy and for improving prognosis. In this study, we aimed to determine the frequency of and the risk factors for the development of epilepsy in patients with neonatal seizures.

METHODS

The hospital files of 228 children who experienced seizures in the neonatal period were reviewed. The frequency of epilepsy and risk factors for the development of epilepsy were determined at age 36 months.

RESULTS

Epilepsy was diagnosed in 40.8% of the cases. Univariate analysis revealed family history of epilepsy, parental consanguinity, abnormal neurological examination findings, microcephaly, unresponsiveness to antiepileptic drugs or antiseizure medication, use of more than one antiepileptic drugs to antiseizure medication at discharge, status epilepticus, electroencephalography abnormalities, abnormal neuroimaging findings, invasive ventilation requirement, myoclonic seizures, central nervous system malformation, and congenital metabolic disease as risk factors for the development of epilepsy. Of these, a family history of epilepsy, abnormal neurological examination findings at discharge, and use of at least two antiepileptic drugs to antiseizure medication at discharge were found as independent risk factors in multivariate analysis.

CONCLUSIONS

Neonatal seizures appear to be associated with epilepsy in more than one-third of the patients. Of the newborns with seizures, those with a family history of epilepsy, abnormal neurological examination findings at discharge, and those using at least two antiepileptic drugs to antiseizure medication at discharge should be monitored more carefully for the development of epilepsy.

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

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

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.

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

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

Precision Medicine in Neonates: A Tailored Approach to Neonatal Brain Injury

Despite advances in neonatal care to prevent neonatal brain injury and neurodevelopmental impairment, predicting long-term outcome in neonates at risk for brain injury remains difficult. Early prognosis is currently based on cranial ultrasound (CUS), MRI, EEG, NIRS, and/or general movements assessed at specific ages, and predicting outcome in an individual (precision medicine) is not yet possible. New algorithms based on large databases and machine learning applied to clinical, neuromonitoring, and neuroimaging data and genetic analysis and assays measuring multiple biomarkers (omics) can fulfill the needs of modern neonatology. A synergy of all these techniques and the use of automatic quantitative analysis might give clinicians the possibility to provide patient-targeted decision-making for individualized diagnosis, therapy, and outcome prediction. This review will first focus on common neonatal neurological diseases, associated risk factors, and most common treatments. After that, we will discuss how precision medicine and machine learning (ML) approaches could change the future of prediction and prognosis in this field.

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.

Clinical seizures and unfavorable brain MRI patterns in neonates with hypoxic ischemic encephalopathy

The aim was to examine whether clinical seizures and amplitude-integrated electroencephalogram (aEEG) patterns in infants with hypoxic ischemic encephalopathy (HIE) can predict the extent of brain injury on magnetic resonance images (MRI) and the long-term neurodevelopmental outcomes at 18∼24 months of age.HIE infants who underwent therapeutic hypothermia (TH) between June 2014 and March 2017 were included in this study. Infants with clinical seizure were analyzed for aEEG patterns and the extent of brain injury on MRI findings. Clinical seizure, aEEG, and brain MRI were assessed and compared with neurodevelopmental outcomes at 18∼24 months of age.Among the 97 HIE infants enrolled in this study with brain MRI scans, 78 (73.1%) TH-treated HIE infants exhibited clinical seizures. More abnormalities on a EEGs and more significant use of first and second antiepileptic drugs (AEDs) were significantly higher in the clinical-seizure group with longer hospitalized days. At a corrected 18 to 24 months of age, HIE infants in the clinical-seizure group with more extension of injury lesions on diffusion-weighted MRI scans exhibited significantly more delayed neurodevelopment. A risk factor analysis indicated that male infants who stayed in the hospital for more than 11 days were at a higher risk of having clinical seizures. The lesion size in MRI greater than 37 pixels was a risk factor with an 81.8% accuracy.Seizures in HIE infants may predict abnormal brain MRI scans and abnormal neurodevelopment at 18 to 24 months of age.

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.

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.

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

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

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

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

Distinguishing Epileptiform Discharges From Normal Electroencephalograms Using Scale-Dependent Lyapunov Exponent

Epileptiform discharges are of fundamental importance in understanding the physiology of epilepsy. To aid in the clinical diagnosis, classification, prognosis, and treatment of epilepsy, it is important to develop automated computer programs to distinguish epileptiform discharges from normal electroencephalogram (EEG). This is a challenging task as clinically used scalp EEG often contains a lot of noise and motion artifacts. The challenge is even greater if one wishes to develop explainable rather than black-box based approaches. To take on this challenge, we propose to use a multiscale complexity measure, the scale-dependent Lyapunov exponent (SDLE). We analyzed 640 multi-channel EEG segments, each 4 s long. Among these segments, 540 are short epileptiform discharges, and 100 are from healthy controls. We found that features from SDLE were very effective in distinguishing epileptiform discharges from normal EEG. Using Random Forest Classifier (RF) and Support Vector Machines (SVM), the proposed approach with different features from SDLE robustly achieves an accuracy exceeding 99% in distinguishing epileptiform discharges from normal control ones. A single parameter, which is the ratio of the spectral energy of EEG signals and the SDLE and quantifies the regularity or predictability of the EEG signals, is introduced to better understand the high accuracy in the classification. It is found that this regularity is considerably greater for epileptiform discharges than for normal controls. Robustly having high accuracy in distinguishing epileptiform discharges from normal controls irrespective of which classification scheme being used, the proposed approach has the potential to be used widely in a clinical setting.

Distinguishing Epileptiform Discharges From Normal Electroencephalograms Using Adaptive Fractal and Network Analysis: A Clinical Perspective

Epilepsy is one of the most common disorders of the brain. Clinically, to corroborate an epileptic seizure-like symptom and to find the seizure localization, electroencephalogram (EEG) data are often visually examined by a clinical doctor to detect the presence of epileptiform discharges. Epileptiform discharges are transient waveforms lasting for several tens to hundreds of milliseconds and are mainly divided into seven types. It is important to develop systematic approaches to accurately distinguish these waveforms from normal control ones. This is a difficult task if one wishes to develop first principle rather than black-box based approaches, since clinically used scalp EEGs usually contain a lot of noise and artifacts. To solve this problem, we analyzed 640 multi-channel EEG segments, each 4s long. Among these segments, 540 are short epileptiform discharges, and 100 are from healthy controls. We have proposed two approaches for distinguishing epileptiform discharges from normal EEGs. The first method is based on Signal Range and EEGs' long range correlation properties characterized by the Hurst parameter H extracted by applying adaptive fractal analysis (AFA), which can also maximally suppress the effects of noise and various kinds of artifacts. Our second method is based on networks constructed from three aspects of the scalp EEG signals, the Signal Range, the energy of the alpha wave component, and EEG's long range correlation properties. The networks are further analyzed using singular value decomposition (SVD). The square of the first singular value from SVD is used to construct features to distinguish epileptiform discharges from normal controls. Using Random Forest Classifier (RF), our approaches can achieve very high accuracy in distinguishing epileptiform discharges from normal control ones, and thus are very promising to be used clinically. The network-based approach is also used to infer the localizations of each type of epileptiform discharges, and it is found that the sub-networks representing the most likely location of each type of epileptiform discharges are different among the seven types of epileptiform discharges.

Seizures severity during rewarming can predict seizure outcomes of infants with neonatal hypoxic-ischemic encephalopathy following therapeutic hypothermia

Background

The aim of this study was to examine the predictive value of amplitude-integrated electroencephalography (aEEG) on 12-month seizure outcomes of infants with neonatal hypoxic-ischemic encephalopathy (HIE) treated with therapeutic hypothermia.

Methods

We conducted this retrospective cohort study in a tertiary neonatal intensive care unit between May 2012 and September 2017. Neonates with HIE who received both therapeutic hypothermia (TH) and aEEG were enrolled.

Results

A total of 23 infants (14 boys, nine girls) with a mean gestational age of 38.9 weeks were enrolled. Fifteen (65%) infants had moderate HIE and eight (35%) had severe HIE according to modified Sarnat staging. The mean aEEG recording time was 107.5 h. Twenty (86.9%) infants had seizure activity during the first 24 h after cooling and 14 (60.8%) had seizure activity during the first 24 h after rewarming. At 12 months, five (21.7%) infants had poor seizure outcomes. Repetitive seizures or status epilepticus pattern during the first 24 h after rewarming, but not the first 24 h after cooling, were associated with the presence of epilepsy at 12 months (p = 0.037).

Conclusions

We identified a high incidence of electrographic seizures in infants with neonatal HIE treated with therapeutic hypothermia, and post-neonatal epilepsy in the children who survived after HIE. Repetitive seizures or status epilepticus pattern during the first 24 h after rewarming, but not in the first 24 h after cooling, were associated with the presence of epilepsy at 12 months.

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.

Delay in Treatment of Neonatal Seizures: A Retrospective Cohort Study

INTRODUCTION

Neonatal seizures are common and caused by a variety of underlying disorders. There is increasing evidence that neonatal seizures result in further brain damage.

OBJECTIVE

To describe the time interval between diagnosis of amplitude-integrated electroencephalography (aEEG)-confirmed seizures and administration of anti-epileptic drugs (AEDs).

METHODS

Single-centre retrospective cohort study, with full-term infants (n = 106) admitted to a level III neonatal intensive care unit between 2012 and 2017 with seizures confirmed on 2-channel aEEG and corresponding raw electroencephalography traces, treated with AEDs. The time interval between the first seizure on the aEEG registration and AED administration was calculated. Factors associated with early treatment were analysed.

RESULTS

The median time interval of initiating treatment of aEEG-confirmed seizures was 01:50 h (interquartile range 00:43-4:30 h). Treatment of aEEG-confirmed seizures was initiated <1 h in 34/106 infants (32.1%), between 1 and 2 h in 21/106 infants (19.8%), 2-4 h in 23/106 infants (21.7%), 4-8 h in 14/106 infants (13.2%), and ≥8 h in 14/106 infants (13.2%). Seizures treated <1 h were significantly more often recognized by the seizure detection algorithm (SDA) compared to seizures treated >1 h (67 vs. 42%, p = 0.02) and showed more clinical signs (79.4 vs. 37.5%, p < 0.01). There was no difference for out-of-office hours (23.5 vs. 22.2%, p = 0.88).

CONCLUSION

With only 32.1% of the seizures being treated <1 h, there is room for improvement. Timely treatment occurred more often when seizures were clinical or recognised by the SDA. aEEG is a helpful tool for diagnosing seizures 24/7.

Assessing the Feasibility of Providing a Real-Time Response to Seizures Detected With Continuous Long-Term Neonatal Electroencephalography Monitoring

PURPOSE

Continuous video electroencephalography (cEEG) monitoring is the recommended gold standard of care for at-risk neonates but is not available in many Neonatal Intensive Care Units (NICUs). To conduct a randomized treatment trial of levetiracetam for the first-line treatment of neonatal seizures (the NEOLEV2 trial), we developed a monitoring infrastructure at five NICUs, implementing recent technological advancements to provide continuous video EEG monitoring and real-time response to seizure detection. Here, we report on the feasibility of providing this level of care.

METHODS

Twenty-five key informant interviews were conducted with study neurologists, neonatologists, coordinators, and EEG technicians from the commercial EEG monitoring company Corticare. A general inductive approach was used to analyze these qualitative data.

RESULTS

A robust infrastructure for continuous video EEG monitoring, remote review, and real-time seizure detection was established at all sites. At the time of this survey, 260 babies had been recruited and monitored for 2 to 6 days. The EEG technician review by the commercial EEG monitoring company was reassuring to families and neonatologists and led to earlier detection of seizures but did not reduce work load for neurologists. Neurologists found the automated neonatal seizure detector algorithm provided by the EEG software company Persyst useful, but the accuracy of the algorithm was not such that it could be used without review by human expert. Placement of EEG electrodes to initiate monitoring, especially after hours, remains problematic.

CONCLUSIONS

Technological advancements have made it possible to provide at-risk neonates with continuous video EEG monitoring, real-time detection of and response to seizures. However, this standard of care remains unfeasible in usual clinical practice. Chief obstacles remain starting a recording and resourcing the real-time specialist review of suspect seizures.

Detection of seizure patterns with multichannel amplitude-integrated EEG and the color density spectral array in the adult neurology intensive care unit

This study's purpose was to determine the sensitivity, false-positive and false-negative of seizure detection in adult intensive care by amplitude-integrated electroencephalography (aEEG) and color density spectral array (CDSA).30 continuous electroencephalogram (EEG) recordings were randomly performed in 3 digital EEG-recording machines, 3 specialized neurophysiologists participated in this study, underwent 4 hours of training of CDSA and aEEG, marked any epochs suspected to be seizures without access to the raw EEG. The results will be compared and analyzed with continuous EEG reading to consider sensitivity, positive or negative rate.The recordings in this study, comprised 720 hours of EEG containing a total of 435 seizures. The median sensitivity for seizure identification was 80% of CDSA and 81.3% of aEEG, Median false-positive was 4 per 24 hours of CDSA, and 2 per 24 hours of aEEG display, Median false-negative was 4 per 24 hours of CDSA, and 4 per 24 hours of aEEG display. The time spent in identification of seizures by CDSA and aEEG was much time-saving than continuous EEG-reading.In this study, both CDSA and aEEG have a higher sensitivity but lower false-positive or missed rate in the interpretation of seizure identification in adult NICU.

LyTONEPAL: long term outcome of neonatal hypoxic encephalopathy in the era of neuroprotective treatment with hypothermia: a French population-based cohort

Background

Hypoxic-ischemic encephalopathy (HIE) is a rare neonatal condition affecting about 1‰ births. Despite a significant improvement in the management of this condition in the last ten years, HIE remains associated with high rates of death and severe neurological disability. From September 2015 to March 2017, a French national cohort of HIE cases was conducted to estimate the extent of long-term moderate and severe neurodevelopmental disability at 3 years and its determinants.

Methods

This prospective population-based cohort includes all moderate or severe cases of HIE, occurring in newborns delivered between 34 and 42 completed weeks of gestation and admitted to a neonatal intensive care unit. Detailed data on the pregnancy, delivery, and newborn until hospital discharge was collected from the medical records in maternity and neonatology units. All clinical examinations including biomarkers, EEG, and imaging were recorded. To ensure the completeness of HIE registration, a registry of non-included eligible neonates was organized, and the exhaustiveness of the cohort is currently checked using the national hospital discharge database. Follow-up is organized by the regional perinatal network, and 3 medical visits are planned at 18, 24 and 36 months. One additional project focused on early predictors, in particular early biomarkers, involves a quarter of the cohort.

Discussion

This cohort study aims to improve and update our knowledge about the incidence, the prognosis and the etiology of HIE, and to assess medical care. Its final objective is to improve the definition of this condition and develop prevention and management strategies for high-risk infants.

Trial registration

NCT02676063. Date of registration (Retrospectively Registered): February 8, 2016.

Inter-observer reliability in reading amplitude-integrated electroencephalogram in the newborn intensive care unit

AIM

Amplitude-integrated electroencephalogram (aEEG) is widely used in neonates to detect electrical seizure and predict outcome following hypoxic ischaemic encephalopathy and other encephalopathy. Because accurate interpretation is important for clinical decision-making and family counselling, inter-observer reliability is a major concern. We aimed to evaluate inter-observer reliability in the interpretation of aEEG tracings in a neonatal intensive care unit.

METHODS

Three neonatal intensive care unit clinicians with different levels of experience in reading aEEG independently reviewed and scored aEEG traces using standardised criteria, categories and interpretation rules. Inter-observer reliability was evaluated using weighted Cohen's κ and intra-class correlation coefficients.

RESULTS

All 131 tracings from 120 neonates were reviewed by the neontalogist, 128 (97.7%) by the clinical nurse specialist, 73 (55.7%) by the nurse educator and 70 (53.4%) by all three clinicians. The majority (88 of 120, 73.3%) were term infants (mean gestational age 38 weeks, standard deviation 3.2). Average duration of recording was 27 h (standard deviation 19.1, range 1-105 h). Inter-observer reliability varied across categories and observers - from very good to excellent for the main background activity (intra-class correlation coefficients 0.93-0.98); good to very good for seizures; and moderate to very good for sleep-wake cycle and quality of recording (weighted κs' 0.71-0.85, 0.50-0.75, 0.46-0.81, respectively).

CONCLUSION

While certain aEEG features appear challenging to inter-observer reliability, our findings suggest that with training and consensus guidelines, levels of reliability needed to enhance clinical and prognostic usefulness of aEEG are achievable across clinicians with different levels of experience in reading aEEG.

Reduced infancy and childhood epilepsy following hypothermia-treated neonatal encephalopathy

OBJECTIVE

To investigate what proportion of a regional cohort of cooled infants with neonatal encephalopathy develop epilepsy (determined by the International League Against Epilepsy [ILAE] definition and the number of antiepileptic drugs [AEDs]) up to 8 years of age.

METHODS

From 2006-2013, 151 infants with perinatal asphyxia underwent 72 h cooling. Clinical and amplitude-integrated electroencepalography (aEEG) with single-channel EEG-verified neonatal seizures were treated with AEDs. Brain magnetic resonance imaging (MRI) was assessed using a 0-11 severity score. Postneonatal seizures, epilepsy rates, and AED treatments were documented. One hundred thirty-four survivors were assessed at 18-24 months; adverse outcome was defined as death or Bayley III composite Cognition/Language or Motor scores <85 and/or severe cerebral palsy or severely reduced vision/hearing. Epilepsy rates in 103 children age 4-8 years were also documented.

RESULTS

aEEG confirmed seizures occurred precooling in 77 (57%) 151 of neonates; 48% had seizures during and/or after cooling and received AEDs. Only one infant was discharged on AEDs. At 18-24 months, one third of infants had an adverse outcome including 11% mortality. At 2 years, 8 (6%) infants had an epilepsy diagnosis (ILAE definition), of whom 3 (2%) received AEDs. Of the 103 4- to 8-year-olds, 14 (13%) had developed epilepsy, with 7 (7%) receiving AEDs. Infants/children on AEDs had higher MRI scores than those not on AEDs (median [interquartile range] 9 [8-11] vs. 2 [0-4]) and poorer outcomes. Nine (64%) of 14 children with epilepsy had cerebral palsy compared to 13 (11%) of 120 without epilepsy, and 10 (71%) of 14 children with epilepsy had adverse outcomes versus 23 (19%) of 120 survivors without epilepsy. The number of different AEDs given to control neonatal seizures, aEEG severity precooling, and MRI scores predicted childhood epilepsy.

SIGNIFICANCE

We report, in a regional cohort of infants cooled for perinatal asphyxia, 6% with epilepsy at 2 years (2% on AEDs) increasing to 13% (7% on AEDs) at early school age. These AED rates are much lower than those reported in the cooling trials, even with adjusting for our cohort's milder asphyxia. Long-term follow-up is needed to document final epilepsy rates.

Evaluation of Dry Sensors for Neonatal EEG Recordings

PURPOSE

Neonatal seizures are a common neurologic diagnosis in neonatal intensive care units, occurring in approximately 14,000 newborns annually in the United States. Although the only reliable means of detecting and treating neonatal seizures is with an electroencephalography (EEG) recording, many neonates do not receive an EEG or experience delays in getting them. Barriers to obtaining neonatal EEGs include (1) lack of skilled EEG technologists to apply conventional wet electrodes to delicate neonatal skin, (2) poor signal quality because of improper skin preparation and artifact, and (3) extensive time needed to apply electrodes. Dry sensors have the potential to overcome these obstacles but have not previously been evaluated on neonates.

METHODS

Sequential and simultaneous recordings with wet and dry sensors were performed for 1 hour on 27 neonates from 35 to 42.5 weeks postmenstrual age. Recordings were analyzed for correlation and amplitude and were reviewed by neurophysiologists. Performance of dry sensors on simulated vernix was examined.

RESULTS

Analysis of dry and wet signals showed good time-domain correlation (reaching >0.8), given the nonsuperimposed sensor positions and similar power spectral density curves. Neurophysiologist reviews showed no statistically significant difference between dry and wet data on most clinically relevant EEG background and seizure patterns. There was no skin injury after 1 hour of dry sensor recordings. In contrast to wet electrodes, impedance and electrical artifact of dry sensors were largely unaffected by simulated vernix.

CONCLUSIONS

Dry sensors evaluated in this study have the potential to provide high-quality, timely EEG recordings on neonates with less risk of skin injury.

Value of electroencephalographic monitoring in newborns with hypoxic-ischemic encephalopathy treated with hypothermia

BACKGROUND

The values of electroencephalography (EEG) in neonatal hypoxic-ischemic encephalopathy (HIE) during therapeutic hypothermia (TH) are still uncertain.

AIMS

The aim of this study is to detect EEG background, the prevalence of seizures during cooling, and to determine different EEG patterns that can predict brain injury in magnetic resonance imaging (MRI).

PATIENTS AND METHODS

Thirty-nine newborns with HIE were subjected to TH. Continuous monitoring by video-EEG was carried out throughout cooling and during rewarming. MRI was done for all newborns after rewarming. The predictive value of EEG background for MRI brain injury was evaluated at 6-h intervals during cooling and rewarming.

RESULTS

At all-time intervals, normal EEG was associated with no or mild MRI brain injury. At the beginning of cooling, normal background was more predictive of a favorable MRI outcome than at later time points. After 24 h of monitoring, diffuse burst suppression and depressed patterns had the greatest prognostic value. In most patients, a discontinuous pattern was not associated with poor prognosis. Thirty-one percent developed electrical seizures, and 8% developed status epilepticus. Seizures were subclinical in 42%. There is a significant association between duration of seizure patterns detected on the EEG and severity of brain injury on MRI.

CONCLUSIONS

Continuous EEG monitoring in newborns with HIE under cooling has a prognostic value about early MRI brain injury and identifies electrographic seizures, approximately 50% of which are subclinical. Treatment of clinical and subclinical seizure results in a reduction of the total duration of seizure pattern supports the hypothesis that subclinical seizures should be treated.

Treating EEG Seizures in Hypoxic Ischemic Encephalopathy: A Randomized Controlled Trial

BACKGROUND

The impact of treating electrographic seizures in hypoxic ischemic encephalopathy (HIE) is unknown.

METHODS

Neonates ≥36 weeks with moderate or severe HIE were randomly assigned to either treatment of electrographic seizures alone (ESG) or treatment of clinical seizures (CSG). Conventional EEG video was monitored in both groups for up to 96 hours. Cumulative electrographic seizure burden (SB) was calculated in seconds and converted to log units for analysis. MRI scans were scored for severity of brain injury. Infants underwent neurodevelopmental evaluation at 18 to 24 months. Statistical analyses were performed by using SAS 9.3 version (SAS Institute, Inc, Cary, NC).

RESULTS

Thirty-five of 69 neonates (51%) who were randomly assigned and included in the study developed seizures (15 in ESG and 20 in CSG). Excluding infants with status epilepticus, median SB (interquartile range) in seconds in ESG (n = 10) was lower than in CSG (n = 16) (449 [113-2070] vs 2226 [760-7654]; P = .02). ESG had fewer seizures with shorter time to treatment (P = .04). Twenty-four of 30 (80%) surviving infants with seizures underwent neurodevelopmental evaluation at 18 to 24 months. Increasing SB in the combined cohort was significantly associated with higher brain injury scores (P < .03) and lower performance scores across all 3 domains on BSID III (P = .03).

CONCLUSIONS

In neonates with HIE, EEG monitoring and treatment of electrographic seizures results in significant reduction in SB. SB is associated with more severe brain injury and significantly lower performance scores across all domains on BSID III.

Early Anatomical Injury Patterns Predict Epilepsy in Head Cooled Neonates With Hypoxic-Ischemic Encephalopathy

BACKGROUND

Our aim was to determine whether early anatomical injury patterns on magnetic resonance imaging-correlate with the development of postneonatal epilepsy in infants treated with selective head cooling for hypoxic-ischemic encephalopathy.

METHODS

We retrospectively analyzed infants ≥35 weeks' gestation born between 2008 and 2013 and followed for at least one year at Northwestern University. All had brain magnetic resonance imaging scans at days 4-5 and electroencephalographs during rewarming and at 3 to 6 months of age.

RESULTS

Outcome was favorable for our cohort of 73 individuals with a mean follow-up of 41 (±7) months. The majority (66%) survived with no seizure recurrence, whereas 13 (18%) developed postneonatal epilepsy, including eight who had infantile spasms. Twelve infants (16%) died. The most common magnetic resonance imaging pattern was diffuse brain injury involving both cortical and subcortical gray matter (26/73, 35%), followed by cortical and subcortical white matter injury (18/73, 25%) and normal magnetic resonance imaging (16/73, 22%). In 13 infants (18%), the brainstem was involved in addition to cortical and subcortical gray matter; nine died and all four surviving infants developed infantile spasms. All 18 infants with cortical and subcortical white matter injury survived and none developed postneonatal epilepsy. The risk of postneonatal epilepsy was associated with injury involving subcortical regions (basal ganglia, thalamus ± brainstem) (12/39 versus 1/34, P < 0.003).

CONCLUSIONS

Brainstem injury was highly predictive of infantile spasms, whereas cortical injury alone predicted low risk for short-term postneonatal epilepsy. Location of anatomical injury on magnetic resonance imaging can be an early predictive factor for development of infantile spasms and inform prognostic decisions in newborns treated with selective head cooling for hypoxic-ischemic encephalopathy.

Systematic review of neonatal seizure management strategies provides guidance on anti-epileptic treatment

There is a lack of scientific evidence to support the best management of neonatal seizures. Current strategies for neonatal seizure management were investigated by analysis of all surveys published during the time period 2000-2012. Methods for seizure diagnosis and availability of electroencephalogram (EEG), including monitoring, varied. Phenobarbital was the drug of first choice, and the use of off-label drugs and treatment times varied.

CONCLUSION

We conclude that there is an urgent need for more evidence-based studies to guide neonatal seizure management.

Epilepsy after neonatal seizures: literature review

INTRODUCTION

Acute neonatal seizures are the most frequent neurological complication in the neonatal intensive care units and the seizing newborns have an increased risk of long-term morbidity. However, the relationship between neonatal seizures and the development of epilepsy later in life is still unclear.

METHODS

We performed a literature review using the search terms "neonatal seizures AND outcome", "neonatal seizures AND epilepsy", "neonatal seizures AND post-neonatal epilepsy", including secondary sources of data such as reference lists of articles reviewed. From the studies in which data were available, the incidence of epilepsy was calculated by dividing the number of all subjects who developed epilepsy in the different studies considered with the number of all newborns enrolled to the studies less the number of patients lost at follow-up.

RESULTS

We found 44 studies published between 1954 and 2013, of which 4 were population-based studies and the remaining were hospital-based case series. The overall population evaluated was 4538 newborns and 17.9% developed post-neonatal epilepsy, with an onset within the first year of life in 68.5% of the patients. In 80.7%, epilepsy was associated with other neurological impairments.

CONCLUSION

Estimates on epilepsy after neonatal seizures vary widely depending on selection criteria and length of the follow-up. However, it represents a common outcome of these newborns, especially in those with severe brain injury and additional neurodevelopmental disabilities.

Evaluation of cerebral function in high risk term infants by using a scoring system based on aEEG

OBJECTIVE

To investigate the relationship between the amplitude integrated electroencephalogram (aEEG) findings and neurodevelopmental outcomes of high-risk term infants with neurological disorders and develop a scoring system for assessment of the cerebral function.

METHODS

The neurological outcome was assessed at 12- to 18-month of age by using the Bayley Scales of Infant Development II. Valuation of the classification of aEEG background pattern, epileptic electrical activity and sleep-weak cycle (SWC) was conducted to develop a new scoring system. The correlation between the summarized scores and outcome analyzed, and the predictive test of the score system was calculated.

RESULTS

A total of 81 infants (39 with asphyxia, 10 with hypoglycemia, 15 with acute bacterial meningoencephalitis, 10 with hyperbilirubinemia and 7 with inborn errors of metabolism) enrolled in the study. The neurological outcome was positive correlated with the background pattern, electrical activity, SWC and summarized scores of the score system based on aEEG. The scoring system has a higher r value, specificity, PPV and lower sensitivity compared with the separate entities such as background pattern, seizures and SWC. The area under the receiver operator characteristics (ROC) curve for predicting outcome by the scoring system was 0.93 (95% CI, 0.878-0.990), with the cut-off value of 7.5.

CONCLUSIONS

aEEG maybe a potential tool for monitoring cerebral function in term infants at risk for poor neurodevelopmental outcomes. Our proposed scoring system based on aEEG could quantify information provided by aEEG objectively and could be a good predictor for neurological outcome.

Neonatal seizures: magnetic resonance imaging adds value in the diagnosis and prediction of neurodisability

AIM

To determine the aetiological associations, neurological sequelae and role of magnetic resonance imaging (MRI) in term newborn infants with seizures.

METHODS

Cohort study of infants ≥37 weeks' gestation delivered in a tertiary level centre, prospectively identified and followed longitudinally for 18-24 months.

RESULTS

An underlying aetiology was found in 95% of the 77 infants identified with seizures (3.0/1000 live births). The most common diagnosis was hypoxic-ischaemic encephalopathy (HIE) (65%), followed by neonatal stroke (12%). Nine infants died, 28 of the 68 survivors developed neurodevelopmental impairment (NDI), and 15 had recurrent seizures in the first 2 years, with both outcomes more likely in those with a diagnosis other than HIE. Abnormal MRI findings were found in 45 of the 70 infants imaged. The absence of major cerebral lesions was highly predictive of a normal neurological outcome.

CONCLUSION

We report the first cohort of term infants with seizures fully investigated by MRI. The universal use of MRI enabled a cause to be identified in 95% of cases. The probability of having NDI or recurrence of seizures was extremely low with absence of major cerebral lesions on MRI. This study demonstrates the added value of MRI for diagnosis of aetiology and the prediction of neurological outcome.

Neonatal seizures: aetiology by means of a standardized work-up

Neonatal seizures are an alarming symptom and are frequent in neonates. It is important to find the cause of neonatal seizures to start a specific treatment and to give a meaningful prognosis. The aim of this study is to investigate the incidence of different aetiologies of neonatal seizures in our hospital by a specific work-up.

METHODS

All full-term born neonates from January 2002 till September 2009 with neonatal seizures, admitted to our neonatal intensive care unit were included (n = 221). Aetiology was investigated by means of a standardized aetiologic work-up.

RESULTS

The frequencies of aetiologies of neonatal seizures were: hypoxic-ischemic encephalopathy (HIE) (n = 119; 53.9%), metabolic or electrolyte disorders (n = 24; 10.9%), intracranial hemorrhage (n = 20; 9.0%), ischemic infarction (n = 16; 7.2%), intracranial infections (n = 14; 6.3%), congenital malformations of the central nervous system (n = 7; 3.2%), inborn errors of metabolism (n = 5; 2.3%), epileptic syndromes (n = 1; 0.5%), HIE + hypoglycemia (n = 4; 1.8%), HIE + intracranial hemorrhage (n = 3; 1.4%), HIE + ischemic infarction (n = 1; 0.5%), ischemic infarction + intracranial hemorrhage (n = 1; 0.5%), idiopathic (n = 4, 1.8%), intoxications (n = 1; 0.5%) and unknown (n = 1; 0.5%).

CONCLUSION

Our work-up is a practical tool to find the aetiology of neonatal seizures.

Clinical utility of early amplitude integrated EEG in monitoring term newborns at risk of neurological injury

OBJECTIVE

to test the clinical utility of an early amplitude-integrated electroencephalography (aEEG) to predict short-term neurological outcome in term newborns at risk of neurology injury.

METHODS

this was a prospective, descriptive study. The inclusion criteria were neonatal encephalopathy, neurologic disturbances, and severe respiratory distress syndrome. Sensitivity, specificity, positive and negative predictive values, and likelihood ratio (LR) were calculated. Clinical and demographic data were analyzed. Neurological outcome was defined as the sum of clinical, electroimaging, and neuroimaging findings.

RESULTS

ten of the 21 monitored infants (48%) presented altered short-term neurologic outcome. The aEEG had 90% sensitivity, 82% specificity, 82% positive predictive value, and 90% negative predictive value. The positive LR was 4.95, and the negative LR was 0.12. In three of 12 (25%) encephalopathic infants, the aEEG allowed for a better definition of the severity of their condition. Seizures were detected in eight infants (38%), all subclinical at baseline, and none had a normal aEEG background pattern. The status of three infants (43%) evolved and required two or more drugs for treatment.

CONCLUSIONS

in infants with encephalopathy or other severe illness, aEEG disturbances occur frequently. aEEG provided a better classification of the severity of encephalopathy, detected early subclinical seizures, and allowed for monitoring of the response to treatment. aEEG was a useful tool at the neonatal intensive care unit for predicting poor short-term neurological outcomes for all sick newborn.

Risk factors and scoring system as a prognostic tool for epilepsy after neonatal seizures

BACKGROUND

Neonatal seizures may cause irreversible changes to the immature brain and. A scoring system for early prognostic information could be a useful clinical tool. The aim of the study was to analyze risk factors for epilepsy after neonatal seizures, to validate Garfinkle's scoring system, and to analyze whether a new scoring system is feasible.

METHODS

A retrospective study of 176 newborns (59.1% boys, 40.9% girls, 70.5% term, 29.5% preterm; mean birth weight 2820 g), admitted to the Department of Neonatology, Division of Pediatrics, University Medical Centre, Ljubljana, because of neonatal seizures (clinical and/or neurophysiological), was performed. Epilepsy rate between 2 and 12 years of follow-up was 18.1%. Five independent predictors from Garfinkle's study and other known predictors were entered into hierarchical binary logistic regression models and analyzed through four steps to identify independent predictors of epilepsy. We tested whether any of the predictors was an effect modifier.

RESULTS

Of five potential predictors from Garfinkle's score, electroencephalograph background findings and etiology were predictive. Etiologies, gestation, mode of delivery, duration of seizures, and other risk factors at birth were found to be independent predictors. Duration of seizures has a different effect on prognosis depending on the gestational age.

CONCLUSION

Gestational age determines the association between duration of seizures and epilepsy. Scoring systems to predict development of epilepsy after neonatal seizures need to limit interaction between important predictor variables.

Treatment of neonatal seizures

Seizures occur more often during the neonatal period than at any other period of life. Precise incidence is difficult to delineate and depends on study population and criteria used for diagnosis of seizures. Controversy exists as to whether neonatal seizures themselves cause damage to the developing brain, or if the damage is primarily due to the underlying cause of the seizures. As a result of this controversy there is an ongoing discussion as to whether all seizures (both clinical and subclinical) should be treated. When (sub)clinical seizures are treated, there is no consensus about the most appropriate treatment for neonatal seizures and how to assess the efficacy of treatment. Current therapeutic options to treat neonatal seizures (i.e. primarily first generation antiepileptics) are relatively ineffective. There is an urgent need for prospective, randomized, controlled trials for efficacy and safety of these second-generation antiepileptic drugs in neonates. The aim of this review is to survey current knowledge regarding treatment of neonatal seizures in both term and preterm infants.

Prognostic factors of developmental outcome in neonatal seizures in term infants

BACKGROUND

The purpose of this study was to identify prognostic indicators of neurodevelopmental outcome in term infants who experienced clinical neonatal seizure.

METHODS

This is a retrospective, observational hospital-based study. Term infants who experienced clinical neonatal seizure between January 1999 and December 2009 were enrolled. Adverse outcomes were defined as death, cerebral palsy, global developmental delay, and/or epilepsy. The associations between adverse outcomes and 17 variables, including sex, mode of delivery, being small of gestational age, maternal illness, perinatal insults, meconium stained liquor, Apgar score at 1 and 5 minutes, seizure onset age, seizure type, etiology, electroencephalography (EEG) findings, antiepileptic drug efficacy, presence of metabolic acidosis, and cranial ultrasonographic findings, and presence of congenital heart disease were analyzed.

RESULTS

Among the 232 enrolled infants, 125 had a normal outcome and 14 had mild functional disability (59.9%), and 55 (23.7%) survived with one or more neurodevelopmental impairments (7 with cerebral palsy, 48 with global developmental delay), and 38 (16.4%) died. Forty-seven (23.0%) of the 204 patients who survived after the first discharge had epilepsy. Ten variables were associated with adverse outcome on univariate analysis, but only four variables, i.e., including abnormal cranial ultrasonography findings, abnormal anterior cerebral artery resistance index, abnormal EEG findings, and presence of congenital heart disease were independent predictors on multivariate logistic regression analysis.

CONCLUSION

In term infants with neonatal seizures, several risk factors related to adverse outcome were recognized. Physicians should pay more attention to these factors when handling patients with neonatal seizures.

Evaluation of etiologic and prognostic factors in neonatal convulsions

This study evaluated etiologic and risk factors affecting long-term prognoses of neurologic outcomes in newborns with neonatal seizures. We enrolled patients at chronologic ages of 23-44 months, referred to the Department of Pediatric Neurology, Istanbul Medical Faculty, from January 1, 2007-December 31, 2009, after manifesting seizures in their first postnatal 28 days. Of 112 newborns, 41 were female, 71 were male, 33 were preterm, and 79 were full-term. Perinatal asphyxia (28.6%) and intracranial hemorrhage (17%) were the most common causes of neonatal seizures. Cerebral palsy developed in 27.6% of patients during follow-up. The incidence of epilepsy was 35.7%. Almost 50% of patients manifested developmental delay in one or more areas. Global developmental delay was the most common (50.8%) neurologic disorder. The correlation between gestational age or birth weight and adverse outcomes was nonsignificant. Etiology, Apgar score, need for resuscitation at birth, background electroencephalogram, neonatal status epilepticus, cranial imaging findings, type/duration of antiepileptic treatment, and response to acute treatment were all strong prognostic factors in neurologic outcomes. Neonatal seizures pose a threat of neurologic sequelae for preterm and full-term infants. Although the number of recognized etiologic factors in neonatal seizures has increased because of improvements in neonatology and diagnostic methods, perinatal asphyxia remains the most common factor.

Neonatal seizures and postneonatal epilepsy: a 7-y follow-up study

BACKGROUND

Seizures are one of the most common symptoms of acute neurological disorders in newborns. This study aimed at evaluating predictors of epilepsy in newborns with neonatal seizures.

METHODS

We recruited consecutively 85 neonates with repeated neonatal video-electroencephalogram (EEG)-confirmed seizures between January 1999 and December 2004. The relationship between clinical, EEG, and ultrasound (US) data in the neonatal period and the development of postneonatal epilepsy was investigated at 7 y of age.

RESULTS

Fifteen patients (17.6%) developed postneonatal epilepsy. Partial or no response to anticonvulsant therapy (odds ratio (OR) 16.7, 95% confidence interval (CI): 1.8-155.8, P = 0.01; OR 47, 95% CI: 5.2-418.1, P < 0.01, respectively), severely abnormal cerebral US scan findings (OR: 5.4; 95% CI: 1.1-27.4; P < 0.04), severely abnormal EEG background activity (OR: 9.5; 95% CI: 1.6-54.2; P = 0.01), and the presence of status epilepticus (OR: 6.1; 95% CI: 1.8-20.3; P < 0.01) were found to be predictors of epilepsy. However, only the response to therapy seemed to be an independent predictor of postneonatal epilepsy.

CONCLUSION

Neonatal seizures seem to be related to postneonatal epilepsy. Recurrent and prolonged neonatal seizures may act on an epileptogenic substrate, causing further damage, which is responsible for the subsequent clinical expression of epilepsy.

Long-term neurological outcome of term-born children treated with two or more anti-epileptic drugs during the neonatal period

BACKGROUND

Neonatal seizures may persist despite treatment with multiple anti-epileptic drugs (AEDs).

OBJECTIVE

To determine in term-born infants with seizures that required two or more AEDs, whether treatment efficacy and/or the underlying disorder were related to neurological outcome.

DESIGN/METHODS

We included 82 children (born 1998-2006) treated for neonatal seizures. We recorded mortality, aetiology of seizures, the number of AEDs required, achievement of seizure control, and amplitude-integrated-EEG (aEEG) background patterns. Follow-up consisted of an age-adequate neurological examination. Surviving children were classified as normal, having mild neurological abnormalities, or cerebral palsy (CP).

RESULTS

Forty-seven infants (57%) had status epilepticus. The number of AEDs was not related to neurological outcome. Treatment with three or four AEDs as opposed to two showed a trend towards an increased risk of a poor outcome, i.e., death or CP, odds ratio (OR) 2.74; 95% confidence interval (CI) 0.98-7.69; P=.055. Failure to achieve seizure control increased the risk of poor outcome, OR 6.77; 95%-CI 1.42-32.82, P=.016. Persistently severely abnormal aEEG background patterns also increased this risk, OR 3.19; 95%-CI 1.90-5.36; P<.001. In a multivariate model including abnormal aEEG background patterns, failure to achieve seizure control nearly reached significance towards an increased risk of poor outcome, OR 5.72, 95%-CI 0.99-32.97, P=.051. We found no association between seizure aetiology and outcome.

CONCLUSIONS

In term-born infants with seizures that required two or more AEDs outcome was poorer if seizure control failed. The number of AEDs required to reach seizure control and seizure aetiology had limited prognostic value.

Amplitude-integrated EEG colored according to spectral edge frequency

OBJECTIVE

To improve the interpretability of figures containing an amplitude-integrated electroencephalogram (aEEG), we devised a color scale that allows us to incorporate spectral edge frequency (SEF) information into aEEG figures. Preliminary clinical assessment of this novel technique, which we call aEEG/SEF, was performed using neonatal and early infantile seizure data.

METHODS

We created aEEG, color density spectral array (DSA), and aEEG/SEF figures for focal seizures recorded in seven infants. Each seizure was paired with an interictal period from the same patient. After receiving instructions on how to interpret the figures, eight test reviewers examined each of the 72 figures displaying compressed data in aEEG, DSA, or aEEG/SEF form (12 seizures and 12 corresponding interictal periods) and attempted to identify each as a seizure or otherwise. They were not provided with any information regarding the original record.

RESULTS

The median number of correctly identified seizures, out of a total of 12, was 7 (58.3%) for aEEG figures, 8 (66.7%) for DSA figures and 10 (83.3%) for aEEG/SEF figures; the differences among these are statistically significant (p=0.011). All reviewers concluded that aEEG/SEF figures were the easiest to interpret.

CONCLUSION

The aEEG/SEF data presentation technique is a valid option in aEEG recordings of seizures.

Current management of the infant who presents with neonatal encephalopathy

Neonatal encephalopathy after perinatal hypoxic-ischemic insult is a major contributor to global child mortality and morbidity. Brain injury in term infants in response to hypoxic-ischemic insult is a complex process evolving over hours to days, which provides a unique window of opportunity for neuroprotective treatment interventions. Advances in neuroimaging, brain monitoring techniques, and tissue biomarkers have improved the ability to diagnose, monitor, and care for newborn infants with neonatal encephalopathy as well as predict their outcome. However, challenges remain in early identification of infants at risk for neonatal encephalopathy, determination of timing and extent of hypoxic-ischemic brain injury, as well as optimal management and treatment duration. Therapeutic hypothermia is the most promising neuroprotective intervention to date for infants with moderate to severe neonatal encephalopathy after perinatal asphyxia and has currently been incorporated in many neonatal intensive care units in developed countries. However, only 1 in 6 babies with encephalopathy will benefit from hypothermia therapy; many infants still develop significant adverse outcomes. To enhance the outcome, specific diagnostic predictors are needed to identify patients likely to benefit from hypothermia treatment. Studies are needed to determine the efficacy of combined therapeutic strategies with hypothermia therapy to achieve maximal neuroprotective effect. This review focuses on important concepts in the pathophysiology, diagnosis, and management of infants with neonatal encephalopathy due to perinatal asphyxia, including an overview of recently introduced novel therapies.

Development of later life spontaneous seizures in a rodent model of hypoxia-induced neonatal seizures

PURPOSE

To study the development of epilepsy following hypoxia-induced neonatal seizures in Long-Evans rats and to establish the presence of spontaneous seizures in this model of early life seizures.

METHODS

Long-Evans rat pups were subjected to hypoxia-induced neonatal seizures at postnatal day 10 (P10). Epidural cortical electroencephalography (EEG) and hippocampal depth electrodes were used to detect the presence of seizures in later adulthood (> P60). In addition, subdermal wire electrode recordings were used to monitor age at onset and progression of seizures in the juvenile period, at intervals between P10 and P60. Timm staining was performed to evaluate mossy fiber sprouting in the hippocampi of P100 adult rats that had experienced neonatal seizures.

KEY FINDINGS

In recordings made from adult rats (P60-180), the prevalence of epilepsy in cortical and hippocampal EEG recordings was 94.4% following early life hypoxic seizures. These spontaneous seizures were identified by characteristic spike and wave activity on EEG accompanied by behavioral arrest and facial automatisms (electroclinical seizures). Phenobarbital injection transiently abolished spontaneous seizures. EEG in the juvenile period (P10-60) showed that spontaneous seizures first occurred approximately 2 weeks after the initial episode of hypoxic seizures. Following this period, spontaneous seizure frequency and duration increased progressively with time. Furthermore, significantly increased sprouting of mossy fibers was observed in the CA3 pyramidal cell layer of the hippocampus in adult animals following hypoxia-induced neonatal seizures. Notably, Fluoro-Jade B staining confirmed that hypoxic seizures at P10 did not induce acute neuronal death.

SIGNIFICANCE

The rodent model of hypoxia-induced neonatal seizures leads to the development of epilepsy in later life, accompanied by increased mossy fiber sprouting. In addition, this model appears to exhibit a seizure-free latent period, following which there is a progressive increase in the frequency of electroclinical seizures.

Neonatal electroencephalography: review of a practical approach

Neonatal electroencephalography (EEG) recordings have routinely been performed for more than half a century. ''Old'' technical difficulties are no longer of concern with the advent of modern digital technology. Still, many ''old'' issues are at debate: characterization of neonatal EEG features, identification of EEG waveforms with potential clinical correlates, the role of neonatal EEG in prediction of neurodevelopmental outcome, and use of new devices. In the past decades, neonatal EEG and emerging issues' literature has greatly expanded. In this review, the authors have summarized some of these issues to increase the availability of the information for both clinical and research purposes. They propose an up-to-date concentrated practical approach to this rapidly expanding ''subfield'' of neonatal neurology.