Independent role of neonatal seizures in subsequent neurological outcomes: a population-based study

Current Evidence: Seizures in Extremely Low Gestational Age Newborns (ELGANs)

Extremely low gestational age newborns (ELGANs) are born at or below 28 weeks of gestational age. Despite improved obstetric care, the incidence of preterm birth continues to rise in advanced countries. Preterm birth remains a major cause of infant mortality, and for infants who survive, neonatal seizures are a significant predictor of later neurologic morbidity. However, little is known about risk factors for neonatal seizures in ELGANs. Understanding the association between neonatal seizures and the development of other neurologic disorders is important given the increasing prevalence of ELGANs. Identifying risk factors that contribute to the development of neonatal seizures in ELGANs may offer insights into novel mechanisms of epileptogenesis in the developing brain and improvements in the prevention or treatment of seizures in preterm infants, including ELGANs. In this literature review, we outline the limitations of epidemiologic studies of neonatal seizures in ELGANs and discuss risk factors for neonatal seizures.

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

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

Distinct manifestations and potential mechanisms of seizures due to cortical versus white matter injury in children

PURPOSE

To study seizure manifestations and outcomes in children with cortical versus white matter injury, differences potentially explaining variability of epilepsy in children with cerebral palsy.

METHODS

In this population-based retrospective cohort study, MRIs of children with cerebral palsy due to ischemia or haemorrhage were classified according to presence or absence of cortical injury. MRI findings were then correlated with history of neonatal seizures, seizures during childhood, epilepsy syndromes, and seizure outcomes.

RESULTS

Of 256 children studied, neonatal seizures occurred in 57 and seizures during childhood occurred in 93. Children with neonatal seizures were more likely to develop seizures during childhood, mostly those with cortical injury. Cortical injury was more strongly associated with (1) developing seizures during childhood, (2) more severe epilepsy syndromes (infantile spasms syndrome, focal epilepsy, Lennox-Gastaut syndrome), and (3) less likelihood of reaching > 2 years without seizures at last follow-up, compared to children without cortical injury. Children without cortical injury, mainly those with white matter injury, were less likely to develop neonatal seizures and seizures during childhood, and when they did, epilepsy syndromes were more commonly febrile seizures and self-limited focal epilepsies of childhood, with most achieving > 2 years without seizures at last follow-up. The presence of cortical injury also influenced seizure occurrence, severity, and outcome within the different predominant injury patterns of the MRI Classification System in cerebral palsy, most notably white matter injury.

CONCLUSIONS

Epileptogenesis is understood with cortical injury but not well with white matter injury, the latter potentially related to altered postnatal white matter development or myelination leading to apoptosis, abnormal synaptogenesis or altered thalamic connectivity of cortical neurons. These findings, and the potential mechanisms discussed, likely explain the variability of epilepsy in children with cerebral palsy and epilepsy following early-life brain injury in general.

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

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

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.

Genetic Testing and Hospital Length of Stay in Neonates With Epilepsy

BACKGROUND

We evaluated changes in genetic testing for neonatal-onset epilepsy and associated short-term outcomes over an 8-year period among a cohort of patients in the neonatal intensive care unit (NICU) at a single institution before and after the introduction of sponsored genetic epilepsy testing in January 2018.

METHODS

Our primary outcome was a change in length of stay (LOS) after 2018. We also ascertained severity of illness with the Neonatal Sequential Organ Failure Assessment (nSOFA), type and result of genetic testing, turnaround time to molecular diagnosis (TAT), LOS, antiseizure medications (ASMs), and use of technology at discharge. We compared outcomes using nonparametric tests and difference-in-difference analysis.

RESULTS

Fifty-three infants with genetic testing were included; 20 infants were tested after 2018. A total of 4160 infants in the NICU without genetic testing were used as reference. In the genetic testing group, LOS was 25 days (interquartile range [IQR] 5, 49) pre-2018 and 19 days (IQR 6, 19) post-2018 (P < 0.001 when compared with the reference population in the difference-in-difference analysis). TAT decreased from 51 days to 17 days after 2018 (P = 0.003). ASM number decreased from 4 (IQR 2, 5) to 2 post-2018 (IQR 1, 3) (P = 0.02). Over the same time periods there was no significant change in birth weight, maximum nSOFA score, or technology dependence.

CONCLUSIONS

In this cohort, changes in genetic testing for neonatal-onset epilepsy were associated with shorter LOS that was not explained by changes in severity of illness, birth weight, or the average LOS in the NICU over time. Validation of these results in a larger, multicenter sample size is warranted.

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

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

The longitudinal role of early family risks and early social-emotional problems for friendship quality in preadolescence-A regression model

The quality of a best friendship provides information about how developmentally beneficial it is. However, little is known about possible early risk factors that influence later friendship quality. The present study examined the role of family risks and social-emotional problems (behavioral problems, peer problems, anxious, and depressive symptoms) in early childhood for positive (i.e., support and help) and negative (i.e., conflicts and betrayal) dimensions of friendship quality with their best friend in preadolescence. 293 children (47.9% female) aged 2–4, their parents and teachers participated in the study with three measurement occasions (T1; M_age = 2.81, T2; M_age = 3.76, T3; M_age = 9.69). The last measurement occasion was at the age of 9–11 years. Results of the longitudinal regression model showed that depressive symptoms in early childhood were associated with a lower positive dimension of friendship quality in preadolescence. In contrast, early anxious symptoms were related to a higher positive dimension of friendship quality six years later. Neither family risks, nor behavioral problems and peer problems in early childhood were linked to the positive dimension of friendship quality in preadolescence. No early predictors were found for the negative dimension of friendship quality. Possible reasons for the lack of associations are discussed. Findings suggest that children with early depressive symptoms at 3–5 years of age should be the targets of potential interventions to form high quality friendships in preadolescence. Possible interventions are mentioned.

Neonatal Seizures Revisited

Seizures are the most common neurological disorder in newborns and are most prevalent in the neonatal period. They are mostly caused by severe disorders of the central nervous system (CNS). However, they can also be a sign of the immaturity of the infant’s brain, which is characterized by the presence of specific factors that increase excitation and reduce inhibition. The most common disorders which result in acute brain damage and can manifest as seizures in neonates include hypoxic-ischemic encephalopathy (HIE), ischemic stroke, intracranial hemorrhage, infections of the CNS as well as electrolyte and biochemical disturbances. The therapeutic management of neonates and the prognosis are different depending on the etiology of the disorders that cause seizures which can lead to death or disability. Therefore, establishing a prompt diagnosis and implementing appropriate treatment are significant, as they can limit adverse long-term effects and improve outcomes. In this review paper, we present the latest reports on the etiology, pathomechanism, clinical symptoms and guidelines for the management of neonates with acute symptomatic seizures.

Investigating and managing neonatal seizures in the UK: an explanatory sequential mixed methods approach

Background

Neonatal seizures are difficult to diagnose and, when they are, tradition dictates first line treatment is phenobarbital. There is little data on how consultants diagnose neonatal seizures, choose when to treat or how they choose aetiological investigations or drug treatments. The purpose of this study was to assess the variation across the UK in the management of neonatal seizures and explore paediatricians’ views on their diagnosis and treatment.

Methods

An explanatory sequential mixed methods approach was used (QUAN→QUAL) with equal waiting between stages. We collected quantitative data from neonatology staff and paediatric neurologists using a questionnaire sent to neonatal units and via emails from the British Paediatric Neurology Association. We asked for copies of neonatal unit guidelines on the management of seizures. The data from questionnaires was used to identify16 consultants using semi-structured interviews. Thematic analysis was used to interpret qualitative data, which was triangulated with quantitative questionnaire data.

Results

One hundred questionnaires were returned: 47.7% thought levetiracetam was as, or equally, effective as phenobarbital; 9.2% thought it was less effective. 79.6% of clinicians had seen no side effects in neonates with levetiracetam. 97.8% of unit guidelines recommended phenobarbital first line, with wide variation in subsequent drug choice, aetiological investigations, and advice on when to start treatment. Thematic analysis revealed three themes: ‘Managing uncertainty with neonatal seizures’, ‘Moving practice forward’ and ‘Multidisciplinary team working’. Consultants noted collecting evidence on anti-convulsant drugs in neonates is problematic, and recommended a number of solutions, including collaboration to reach consensus guidelines, to reduce diagnostic and management uncertainty.

Conclusions

There is wide variation in the management of neonatal seizures and clinicians face many uncertainties. Our data has helped reveal some of the reasons for current practice and decision making. Suggestions to improve certainty include: educational initiatives to improve the ability of neonatal staff to describe suspicious events, greater use of video, closer working between neonatologists and neurologists, further research, and a national discussion to reach a consensus on a standardised approach to managing neonatal epileptic seizures.

Lidocaine as treatment for neonatal seizures: Evaluation of previously developed population pharmacokinetic models and dosing regimen

AIMS

Lidocaine is used to treat neonatal seizures refractory to other anticonvulsants. It is effective, but also associated with cardiac toxicity. Previous studies have reported on the pharmacokinetics of lidocaine in preterm and term neonates and proposed a dosing regimen for effective and safe lidocaine use. The objective of this study was to evaluate the previously developed pharmacokinetic models and dosing regimen. As a secondary objective, lidocaine effectiveness and safety were assessed.

METHODS

Data from preterm neonates and (near-)term neonates with and without therapeutic hypothermia receiving lidocaine were included. Pharmacokinetic analyses were performed using non-linear mixed effects modelling. Simulations were performed to evaluate the proposed dosing regimen. Lidocaine was considered effective if no additional anticonvulsant was required and safe if no cardiac adverse events occurred.

RESULTS

Data were available for 159 neonates; 50 (31.4%) preterm and 109 term neonates, of whom 49 (30.8%) were treated with therapeutic hypothermia. Lidocaine clearance increased with postmenstrual age by 0.69%/day (95% confidence interval 0.54-0.84%). During therapeutic hypothermia (33.5°C), lidocaine clearance was reduced by 21.8% (7.26%/°C, 95% confidence interval 1.63-11.2%) compared to normothermia (36.5°C). Simulations demonstrated that the proposed dosing regimen leads to adequate average lidocaine plasma concentrations. Effectiveness and safety were assessed in 92 neonates. Overall effectiveness was 53.3% (49/92) and 56.5% (13/23) for neonates receiving the proposed dosing regimen. No cardiac toxicity was observed.

CONCLUSION

Lidocaine pharmacokinetics was adequately described across the entire neonatal age range. With the proposed dosing regimen, lidocaine can provide effective and safe treatment for neonatal seizures.

Neurodevelopmental outcomes at 9-14 months gestational age after treatment of neonatal seizures due to brain injury

PURPOSE

Infants with brain injury are susceptible to developmental delays. Survivors of neonatal seizures are at risk for developmental delay, epilepsy, and further neurological comorbidities. Despite advances in neonatal critical care, the prevalence of adverse long-term outcomes and seizure recurrence remains unchanged. Our goal is to determine if early treatment of neonatal seizures with phenobarbital or levetiracetam is associated with worse neurodevelopmental outcomes in brain-injured infants.

METHODS

We conducted a retrospective cohort study of 119 infants admitted between 2013 and 2017 who were at risk for developmental delay and assessed in our clinic. We compared brain injury infants with neonatal seizures to brain injury infants without neonatal seizures using Bayley scores (BSID III) at 9-14 months gestational age. A comparison of Bayley scores between those exposed to phenobarbital and levetiracetam was conducted.

RESULTS

Twenty-two children with neonatal seizures scored lower than 53 children without seizures in all domains with significant values in composite scores for cognitive function (p = 0.003) and language (p = 0.031). We found no difference in scores at 9-14 months between infants exposed to phenobarbital versus levetiracetam.

CONCLUSIONS

Our results suggest that in infants with brain injury, the occurrence of neonatal seizures has an adverse effect on neurodevelopmental outcomes. The choice of antiseizure medication may not play a significant role in their outcomes.