Neonatal seizures triple the risk of a remote seizure after perinatal ischemic stroke

Incidence and Predictors of Later Epilepsy in Neonates with Encephalopathy: The Impact of Electrographic Seizures

OBJECTIVES

To determine the incidence of later epilepsy in full-term infants with neonatal encephalopathy (NE) who undergo continuous electroencephalography (cEEG) monitoring in the neonatal period and to identify potential predictors of later epilepsy both in infants with and without electrographic neonatal seizures (ENS).

METHODS

This was a retrospective observational study performed at Cork University Maternity Hospital, Cork, Ireland, between 2003 and 2019. All term infants with NE had a minimum of 2 h of cEEG monitoring in the neonatal period. ENS were identified via cEEG monitoring. Pediatric medical charts were reviewed to determine if epilepsy developed after the neonatal period and to determine potential predictors of epilepsy in infants both with and without ENS.

RESULTS

Two hundred and eighty infants were included. The overall incidence rate of epilepsy was 17.55 per 1000 person-years (95% CI: 10.91 to 28.23). In infants with ENS (n = 82), the incidence rate was 39.27 per 1000 person-years (95% CI: 22.30 to 69.16). In infants without ENS (n = 198), the incidence rate was 7.54 per 1000 person-years (95% CI: 3.14 to 18.12). The incidence rate was significantly higher in the ENS group compared to the non-ENS group (p-value = 0.002). Several potential predictors for the development of later epilepsy were identified including infants delivered vaginally, low Apgar scores at 1 and 5 min, severe HIE diagnosis, presence of ENS, a severely abnormal EEG background and an abnormal brain MRI.

SIGNIFICANCE

Following NE, term infants are at risk of epilepsy with a significantly higher incidence rate in infants who experience ENS compared to those who did not. Close follow-up is required in both groups well into the childhood period.

PLAIN LANGUAGE SUMMARY

This study aimed to determine the occurrence of epilepsy in children who were monitored for seizures in the newborn period. The occurrence of epilepsy was higher in infants who experienced seizures in the newborn period compared to those who did not. Several potential predictors of later epilepsy were identified in both groups of infants (those with and without seizures in the newborn period). Both groups of infants require close follow-up in childhood.

Effectiveness of sodium channel blockers in treating neonatal seizures due to arterial ischemic stroke

OBJECTIVE

Few studies have evaluated the efficacy of antiseizure medications (ASMs) according to the etiology of neonatal acute provoked seizures. We aimed to investigate the response to ASMs in term/near term neonates with acute arterial ischemic stroke (AIS), as well as the type of seizure at presentation and the monitoring approach.

METHODS

We retrospectively evaluated neonates from 15 European level IV neonatal intensive care units who presented with seizures due to AIS and were monitored by continuous electroencephalography (cEEG) and/or amplitude-integrated EEG (aEEG) in whom actual recordings, timing, doses, and response to ASMs were available for review.

RESULTS

One hundred seven neonates were referred, and 88 were included. Of those, 56 met the criteria for evaluating the treatment response. The mean time to treatment was 7.9 h (SD = 16.4), and the most frequently administered first-line ASM was phenobarbital (PB; 74/88, 84.1%). Seizures were controlled within 24 h from onset of symptoms in 64.3% (36/56) of neonates. Phenytoin (PHT) was effective in almost all neonates in whom it was trialed (24/25, 96.0%), whereas PB was effective in only 22.0% of patients (11/50). Infants treated with PB or PHT as first-line treatment (53/56, 94.6%) showed a higher response rate with PHT (6/6, 100.0%) than with PB (11/47, 23.4%). Monitoring approach and seizure types were evaluated in 88 infants. Forty-six of 88 (52.3%) were monitored with cEEG and 47.7% (42/88) with aEEG, with or without intermittent cEEG. The mean monitoring duration was 65.8 h (SD = 39.21). In 83 of 88 (94.3%) infants, the type of seizure suspected clinically prior to monitoring was confirmed afterward. Unilateral focal clonic seizures were seen in 71 of 88 infants (80.7%), whereas 11 of 88 (12.5%) presented with ictal apneas.

SIGNIFICANCE

Our findings provide evidence in a large, homogenous cohort that PHT is more effective than PB in treating neonatal acute symptomatic seizures due to AIS.

Neuroimaging and Neurological Outcomes in Perinatal Arterial Ischemic Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Prediction of outcomes in perinatal arterial ischemic stroke (PAIS) is challenging. We performed a systematic review and meta-analysis to determine whether infarct characteristics can predict outcomes in PAIS.

METHODS

A systematic search was conducted using five databases in January 2023. Studies were included if the sample included children with neonatal or presumed PAIS; if infarct size, location, or laterality was indicated; and if at least one motor, cognitive, or language outcome was reported. The level of evidence and risk of bias were evaluated using the Risk of Bias in Non-Randomized Studies of Interventions tool. Meta-analyses were conducted comparing infarct size or location with neurological outcomes when at least three studies could be analyzed.

RESULTS

Eighteen full-text articles were included in a systematic review with nine included in meta-analysis. Meta-analyses revealed that small strokes were associated with a lower risk of cerebral palsy/hemiplegia compared with large strokes (risk ratio [RR] = 0.263, P = 0.001) and a lower risk of epilepsy (RR = 0.182, P < 0.001). Middle cerebral artery (MCA) infarcts were not associated with a significantly different risk of cerebral palsy/hemiplegia compared with non-MCA strokes (RR = 1.220, P = 0.337). Bilateral infarcts were associated with a 48% risk of cerebral palsy/hemiplegia, a 26% risk of epilepsy, and a 58% risk of cognitive impairment.

CONCLUSIONS

Larger stroke size was associated with worse outcomes across multiple domains. Widely heterogeneous reporting of infarct characteristics and outcomes limits the comparison of studies and the analysis of outcomes. More consistent reporting of infarct characteristics and outcomes will be important to advance research in this field.

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.

Investigating the Impact on Long-Term Outcomes and the Necessity of Hereditary Thrombophilia Screening in Presumed or Perinatal Arterial Ischemic Stroke

This study aimed to investigate the influence of prothrombotic risk factors on long-term outcomes of patients with perinatal arterial ischemic stroke. The study was conducted through an analysis of monitoring results that were regularly maintained for approximately 20 years at a tertiary stroke-monitoring center. The study assessed prothrombotic risk factors, radiological area of involvement, clinical presentation, treatments, clinical outcomes, and long-term outcomes of the 48 patients included in the study, with a mean monitoring time of 77.6 ± 45.7 months (range: 6-204). Our results showed that the presence of prothrombotic risk factors did not affect long-term outcomes. However, patients with middle cerebral artery infarction had the highest risk of developing cerebral palsy, whereas those with presumed stroke had the highest risk of developing epilepsy. This study suggests that prothrombotic risk factors should not be evaluated during the acute stage unless there is a strong suspicion of the patient's history, and prevention or early diagnosis of presumed stroke patients will positively impact their long-term prognosis.

The thalamus and basal ganglia are smaller in children with epilepsy after perinatal stroke

Background

Epilepsy is one of the most serious consequences of perinatal stroke. Epilepsy itself has been proposed as a risk factor for impaired cognitive, language, and behavioral functioning. It is still unclear which children develop epilepsy after perinatal stroke. The current study aimed to evaluate the volume of the thalamus and the basal ganglia in children after perinatal stroke in relation to poststroke epilepsy.

Methods

The follow-up study included 29 children with perinatal arterial ischemic stroke (AIS), 33 children with presumed periventricular venous infarction (PVI), and 46 age- and sex-matched healthy controls. Magnetic resonance imaging was performed in children between the ages of 4 and 18 years, and volumetric analysis by segmentation was used to evaluate the size of the thalamus, caudate nucleus, putamen, globus pallidus, hippocampus, amygdala, and nucleus accumbens.

Results

During a median follow-up time of 12.8 years [interquartile range (IQR): 10.8-17.3] in the AIS group and 12.5 years (IQR: 9.3-14.8) in the PVI group (p = 0.32), epilepsy developed in 10 children (34.5%) with AIS and in 4 (12.1%) children with PVI, p = 0.036 [odds ratio (OR) = 3.8, 95%, confidence interval (CI): 1.04-14]. Epilepsy and interictal epileptiform discharges (IEDs) without clinical seizures were more often expressed in children with AIS (n = 16, 55%) than in children with PVI (n = 7, 21.2%), p = 0.0057 (OR = 3.8 95% CI: 1.04-14). In the AIS group, the ipsilesional and contralesional thalamus, ipsilesional caudate nucleus, and nucleus accumbens were significantly smaller in children with epilepsy compared to children without epilepsy. In the PVI group, the ipsilesional thalamus, caudate nucleus, and nucleus accumbens were smaller in the pooled group of epilepsy plus IED alone compared to children without epilepsy.

Conclusion

In children with AIS, epilepsy or IED occurred more often compared to children with PVI. Both patients with AIS and PVI with severe damage to the basal ganglia and the thalamus have a higher risk of developing poststroke epilepsy and should be monitored more closely throughout childhood to initiate timely antiseizure medication and rehabilitation.

Pediatric Ischemic Stroke

OBJECTIVE

Pediatric cerebrovascular disease is one of the leading causes of death and disability in children. Survivors of childhood stroke and their families are often left to cope with long-lasting sequelae, such as barriers to school reentry and long-term challenges in attaining independence as adults. Because childhood stroke is rare and providers may not be familiar with the disorder, this article reviews the risk factors, acute management, and sequelae of ischemic stroke in children.

LATEST DEVELOPMENTS

High-quality evidence has resulted in an organized approach to emergent treatment of ischemic stroke in adults, but most front-line providers are less prepared for emergent stroke management in children. The level of evidence for reperfusion therapies in children remains low but is growing. Thrombolysis and thrombectomy are sometimes considered for hyperacute treatment of stroke in children. Readiness for pediatric stroke at regional centers should include an organized approach to pediatric stroke triage and management based on extrapolation from adult stroke trials, expert consensus, and emerging pediatric studies.

ESSENTIAL POINTS

This review provides up-to-date information about ischemic stroke risk factors and management in children. Preparation for rapid stroke diagnosis and management in children may improve outcomes.

Effect of neonatal seizure burden and etiology on the long-term outcome: data from a randomized, controlled trial

Background

Neonatal seizures are common, but the impact of neonatal seizures on long-term neurologic outcome remains unclear. We addressed this question by analyzing data from an early-phase controlled trial of bumetanide to treat neonatal seizures.

Methods

Neonatal seizure burden was calculated from continuous video-EEG data. Neurologic outcome was determined by standardized developmental tests and post-neonatal seizure recurrence.

Results

Of 111 enrolled neonates, 43 were randomized to treatment or control groups. There were no differences in neurologic outcome between treatment and control groups. A subgroup analysis was performed for 84 neonates with acute perinatal brain injury (57 HIE, 18 stroke, 9 ICH), most of whom (70%) had neonatal seizures. There was a significant negative correlation between seizure burden and developmental scores (p<0.01). Associations between seizure burden and developmental scores were stronger in HIE and stroke groups compared with ICH (p<0.05).

Conclusion

Bumetanide showed no long-term beneficial or adverse effects, as expected based on treatment duration versus duration of neonatal seizures. For neonates with perinatal brain injury, higher neonatal seizure burden correlated significantly with worse developmental outcome, particularly for ischemic versus hemorrhagic brain injury. These data highlight the need for further investigation of the long-term effects of both neonatal seizure severity and etiology.

Efficacy of the anti-seizure medications in acute symptomatic neonatal seizures caused by stroke. A systematic review

BACKGROUND AND AIM

Neonatal stroke is the second cause of acute symptomatic neonatal seizures after hypoxic-ischemic encephalopathy. The aim of this systematic review is to determine which drug among those available represents the best therapeutic choice for treatment of secondary seizures due to neonatal stroke.

METHODS

We performed a systematic review searching on PubMed the keywords "Neonatal", "Stroke", "Seizures" and "Treatment". Search was limited only to English language with no time limit. Last literature search was done on May 30, 2022.

RESULTS

We selected 5 articles involving a total of 52 full-term neonates. In 96.1% the first line treatment was phenobarbital and in 3.9% was used phenobarbital associated with midazolam from the seizure onset but in all of these cases it was necessary to introduce further medications for controlling the seizures. As second line treatment was used lidocaine (response rate of 53.3%), midazolam (response rate of 15.38%) bumetanide (response rate of 100%), and fosphenytoin (no response). As third line treatment was used lidocaine (response rate of 87.5%), Midazolam (response rate of 60%), levetiracetam and clonazepam (response rate of 100%).

CONCLUSIONS

Our review shows that the use of ASMs that act throughout a gabaergic mechanism are inadequate in controlling seizures secondary to neonatal stroke in full-term newborns. Very effective seems to be lidocaine and levetiracetam with an apparent safer profile in short and long term. Bumetanide shows promising results, but they need to be confirmed by phase 3 studies.

Neurological and Functional Outcomes after Pediatric Stroke

Pediatric stroke results in life-long morbidity for many patients, but the outcomes can vary depending on factors such as age of injury, or mechanism, size, and location of stroke. In this review, we summarize the current understanding of outcomes in different neurological domains (eg, motor, cognitive, language) for children with stroke of different mechanisms (ie, arterial ischemic stroke, cerebral sinus venous thrombosis, and hemorrhagic stroke), but with a focus on World Health Organization International Classification for Functioning, Disability, and Health (ICF-CY) framework for measuring health and disability for children and youth. We describe outcomes for the population as a whole and certain factors that may further refine prognostication.

Validation of central nervous system-induced seizures and other neurological variables in the Swedish Neonatal Quality Register

Aim

We sought to validate neurological variables and relevant International Classification of Diseases, Tenth Revision (ICD‐10) codes in the Swedish Neonatal Quality (SNQ) Register.

Methods

Register data were collected for 351 neonates, born between January 2009 and December 2016, who were treated at a neonatal unit in the Stockholm region on 385 occasions. They were eligible if the check‐box for central nervous system (CNS)‐induced seizures was ticked. The Register data, including relevant ICD‐10 codes, were validated by checking the patients' electronic medical charts.

Results

Most of the neonates were born at term (76%) and weighed >2500 g (80%). The variable CNS‐induced seizures had a positive predictive value of 46%. The ICD‐10 diagnosis P90.9A had a positive predictive value of 90%. This comprises seizures validated with electroencephalography, amplitude‐integrated electroencephalography or continuous function monitoring. The majority of the associated neurological variables in the Register had positive predictive values above 85%.

Conclusion

When the check‐box was ticked for central nervous system‐induced seizures, most of the neurological variables in the Register had high validity. However, the CNS‐induced seizures variable per se had a lower positive predictive value. Future SNQ Register‐based studies of such neonatal seizures should also include ICD‐10 P90.9A.

Whole-exome sequencing with targeted analysis and epilepsy after acute symptomatic neonatal seizures

BACKGROUND

The contribution of pathogenic gene variants with development of epilepsy after acute symptomatic neonatal seizures is not known.

METHODS

Case-control study of 20 trios in children with a history of acute symptomatic neonatal seizures: 10 with and 10 without post-neonatal epilepsy. We performed whole-exome sequencing (WES) and identified pathogenic de novo, transmitted, and non-transmitted variants from established and candidate epilepsy association genes and correlated prevalence of these variants with epilepsy outcomes. We performed a sensitivity analysis with genes associated with coronary artery disease (CAD). We analyzed variants throughout the exome to evaluate for differential enrichment of functional properties using exploratory KEGG searches.

RESULTS

Querying 200 established and candidate epilepsy genes, pathogenic variants were identified in 5 children with post-neonatal epilepsy yet in only 1 child without subsequent epilepsy. There was no difference in the number of trios with non-transmitted pathogenic variants in epilepsy or CAD genes. An exploratory KEGG analysis demonstrated a relative enrichment in cell death pathways in children without subsequent epilepsy.

CONCLUSIONS

In this pilot study, children with epilepsy after acute symptomatic neonatal seizures had a higher prevalence of coding variants with a targeted epilepsy gene sequencing analysis compared to those patients without subsequent epilepsy.

IMPACT

We performed whole-exome sequencing (WES) in 20 trios, including 10 children with epilepsy and 10 without epilepsy, both after acute symptomatic neonatal seizures. Children with post-neonatal epilepsy had a higher burden of pathogenic variants in epilepsy-associated genes compared to those without post-neonatal epilepsy. Future studies evaluating this association may lead to a better understanding of the risk of epilepsy after acute symptomatic neonatal seizures and elucidate molecular pathways that are dysregulated after brain injury and implicated in epileptogenesis.

Clinical analysis of 33 cases with neonatal cerebral infarction

Objective:

To investigate the etiology, clinical manifestations, diagnosis, treatment and prognosis of neonatal cerebral infarction (NCI) to further improve the understanding of the disease.

Methods:

Clinical data and follow-up results of 33 cases of NCI in neonatal intensive care unit of a first-class hospital from September 2009 to September 2019 were retrospectively analyzed.

Results:

All 33 patients were diagnosed with NCI by MRI. Among them, 31 cases (93.94%) were full-term infants, 25 cases (75.76%) were mother’s first birth, and 18 (54.55%) cases were males. Pregnancy complications were reported in 18 cases (54.55%), and 19 cases (57.58%) had perinatal hypoxia history. Seizures were the most common first symptom and clinical manifestation in the course of disease (81.8%). There were 27 cases (81.82%) of patent foramen ovale (PFO) among NCI cohort. Ischemic cerebral infarction occurred in 32 cases (96.97%). The middle cerebral artery and its branches were more frequently involved, mainly on the left side. The acute stage of NCI was managed by symptomatic support treatment, and the recovery stage involved mainly rehabilitation treatment. Among the 33 cases, five cases were lost to follow-up, two patients died, 26 patients survived without complications, one case had cerebral palsy, one case had language retardation, and six cases had dyskinesia. Poor prognosis was associated with the involvement of deep gray matter nuclei or multiple lobes, and intrapartum complications. Vaginal mode of delivery and longer hospital stay were associated with better prognosis.

Conclusions:

Complications leading to placental circulation disorder during pregnancy and perinatal hypoxia are common high-risk factors of NCI. The seizure is the most common clinical manifestation. There is a possible correlation between PFO and NCI. Involvement of deep gray matter or multiple lobes and intrapartum complications may indicate poor prognosis, while vaginal delivery and prolonged hospitalizations are associated with better prognosis of NCI.

Risk Factors for Drug Resistance in Epileptic Children with Age of Onset above Five Years: A Case-Control Study

Background

Children with epilepsy with onset above five years encompass distinct epidemiological and clinical characteristics that may have specific risk factors for resistance to antiseizure medications (ASMs). Studies on this age group are limited.

Purpose

To identify risk factors for drug resistance in children with epilepsy with the age of onset above five years.

Methods

A case-control study was conducted on children with epilepsy with the age of onset above five years visiting the Pediatric Neurology Clinic of Cipto Mangunkusumo and Mohammad Hoesin Hospital between September 2015 and August 2016. Cases consisted of drug-resistant children while control consisted of drug-responsive children according to 2010 ILAE classification. Risk factors studied include onset, number of seizures, illness duration before treatment, cause, seizure type, status epilepticus, initial and evolution of EEG, brain imaging, and initial treatment response.

Results

Thirty-two pairs of children were included in the study. After logistic regression analysis, symptomatic etiology and failure to achieve early response to treatment were found to be associated with drug resistance with adjusted OR of 84.71 (95% CI: 5.18-1359.15) and 72.55 (95% CI: 7.08-743.85), respectively.

Conclusion

Poor initial response to ASM and symptomatic etiology are independent risk factors for drug resistance in children with epilepsy with the age of onset above five years.

Pediatric Ischemic Stroke and Epilepsy: A Nationwide Cohort Study

Background and Purpose

The risk of epilepsy after stroke has not been thoroughly explored in pediatric ischemic stroke. We examined the risk of epilepsy in children with ischemic stroke as well as in their first-degree relatives.

Methods

In Swedish National Registers, we identified 1220 children <18 years with pediatric ischemic stroke diagnosed 1969 to 2016, alive 7 days after stroke and with no prior epilepsy. We used 12 155 age- and sex-matched individuals as comparators. All first-degree relatives to index individuals and comparators were also identified. The risk of epilepsy was estimated in children with ischemic stroke and in their first-degree relatives using Cox proportional hazard regression model.

Results

Through this nationwide population-based study, 219 (18.0%) children with ischemic stroke and 91 (0.7%) comparators were diagnosed with epilepsy during follow-up corresponding to a 27.8-fold increased risk of future epilepsy (95% CI, 21.5–36.0). The risk of epilepsy was still elevated after 20 years (hazard ratio [HR], 7.9 [95% CI, 3.3–19.0]), although the highest HR was seen in the first 6 months (HR, 119.4 [95% CI, 48.0–297.4]). The overall incidence rate of epilepsy was 27.0 per 100 000 person-years (95% CI, 21.1–32.8) after ischemic stroke diagnosed ≤day 28 after birth (perinatal) and 11.6 per 100 000 person-years (95% CI, 9.6–13.5) after ischemic stroke diagnosed ≥day 29 after birth (childhood). Siblings and parents, but not offspring, to children with ischemic stroke were at increased risk of epilepsy (siblings: HR, 1.64 [95% CI, 1.08–2.48] and parents: HR, 1.41 [95% CI, 1.01–1.98]).

Conclusions

The risk of epilepsy after ischemic stroke in children is increased, especially after perinatal ischemic stroke. The risk of epilepsy was highest during the first 6 months but remained elevated even 20 years after stroke which should be taken into account in future planning for children affected by stroke.

Management of seizures in neonates with neonatal encephalopathy treated with hypothermia

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

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

OBJECTIVE

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

Short-term outcomes after a neonatal arterial ischemic stroke

PURPOSE

The purpose of this study is to determine the frequency and radiological predictors of recurrent acute symptomatic seizures (RASS) and motor impairment at discharge after a neonatal arterial ischemic stroke (NAIS).

METHODS

In a nonconcurrent cohort study, 33 full-term newborns with NAIS confirmed by MRI are admitted into our hospital between January 2003 and December 2012. Stroke size, calculated as stroke volume divided by whole brain volume (WBV), was categorized as > or < 3.3% of WBV. A univariate analysis of categorical variables was performed using Fisher's exact test. A multivariate analysis was performed using logistic regression models including all variables with a p value < 0.1 in the univariate analysis.

RESULTS

The median age at NAIS was 2 days (IQR, 1-5.6), 36.4% were girls. The stroke size was > 3.3 of WBV in 48.5% of the cases, and 54.5% showed multifocal lesions. Involvement of the cerebral cortex (54.5%), thalamus (48.5%), posterior limb of the internal capsule (36.4%), basal ganglia (36.4%), and brainstem (28.2%) were found. At discharge, 45.5% of newborns had a motor deficit, and 27.3% had at least two seizures. Multivariate analyses revealed that stroke size > 3.3% of WBV (OR: 8.1, CI: 1.2-53.9) and basal ganglia involvement (OR: 12.8, CI: 1.7-95.4) predicted motor impairment at discharge. Cortical involvement of temporal and frontal lobes (OR: 14, CI: 2.2-88.1; and OR: 9.1, CI: 1.2-72.6) were predictive of RASS.

CONCLUSION

Stroke size and location are independent risk factors for adverse short-term neurological outcomes in full-term newborns following a NAIS.

Epileptogenic modulation index and synchronization in hypsarrhythmia of West syndrome secondary to perinatal arterial ischemic stroke

OBJECTIVE

Perinatal arterial ischemic stroke (PAIS) is associated with epileptic spasms of West syndrome (WS) and long term Focal epilepsy (FE). The mechanism of epileptogenic network generation causing hypsarrhythmia of WS is unknown. We hypothesized that Modulation index (MI) [strength of phase-amplitude coupling] and Synchronization likelihood (SL) [degree of connectivity] could interrogate the epileptogenic network in hypsarrhythmia of WS secondary to PAIS.

METHODS

We analyzed interictal scalp electroencephalography (EEG) in 10 WS and 11 FE patients with unilateral PAIS. MI between gamma (30-70 Hz) and slow waves (3-4 Hz) was calculated to measure phase-amplitude coupling. SL between electrode pairs was analyzed in 9-frequency bands (5-delta, theta, alpha, beta, gamma) to examine inter- and intra-hemispheric connectivity.

RESULTS

MI was higher in affected hemispheres in WS (p = 0.006); no differences observed in FE. Inter-hemispheric SL of 3-delta, theta, alpha, beta, gamma bands was significantly higher in WS (p < 0.001). In WS, modified Z-Score of intra-hemispheric SL values in 3-delta, theta, alpha, beta and gamma in the affected hemispheres were significantly higher than those in the unaffected hemispheres (p < 0.001) as well as 0.5-4 Hz (p = 0.004).

CONCLUSIONS

The significantly higher modulation in affected hemisphere and stronger inter- and intra-hemispheric connectivity generate hypsarrhythmia of WS secondary to PAIS.

SIGNIFICANCE

Epileptogenic cortical-subcortical transcallosal networks from affected hemisphere post-PAIS provokes infantile spasms.

Neonatal Encephalopathy: Beyond Hypoxic-Ischemic Encephalopathy

Neonatal encephalopathy is a clinical syndrome of neurologic dysfunction that encompasses a broad spectrum of symptoms and severity, from mild irritability and feeding difficulties to coma and seizures. It is vital for providers to understand that the term "neonatal encephalopathy" is simply a description of the neonate's neurologic status that is agnostic to the underlying etiology. Unfortunately, hypoxic-ischemic encephalopathy (HIE) has become common vernacular to describe any neonate with encephalopathy, but this can be misleading. The term should not be used unless there is evidence of perinatal asphyxia as the primary cause of encephalopathy. HIE is a common cause of neonatal encephalopathy; the differential diagnosis also includes conditions with infectious, vascular, epileptic, genetic/congenital, metabolic, and toxic causes. Because neonatal encephalopathy is estimated to affect 2 to 6 per 1,000 term births, of which HIE accounts for approximately 1.5 per 1,000 term births, (1)(2)(3)(4)(5)(6) neonatologists and child neurologists should familiarize themselves with the evaluation, diagnosis, and treatment of the diverse causes of neonatal encephalopathy. This review begins by discussing HIE, but also helps practitioners extend the differential to consider the broad array of other causes of neonatal encephalopathy, emphasizing the epidemiology, neurologic presentations, diagnostics, imaging findings, and therapeutic strategies for each potential category.

Perinatal Stroke: A Practical Approach to Diagnosis and Management

Perinatal stroke is a focal vascular brain injury that occurs from the fetal period to 28 days of postnatal age. With an overall incidence of up to 1 in 1,000 live births, the most focused lifetime risk for stroke occurs near birth. Perinatal stroke can be classified by the timing of diagnosis, vessel involvement, and type of injury. Timing of diagnosis may be in the acute neonatal period or retrospectively after a period of normal development, followed by abnormal neurologic findings, with the injury presumed to have occurred around the time of birth. Strokes may be arterial or venous, ischemic, and/or hemorrhagic. Within these classifications, 6 perinatal stroke diseases are recognizable, based on clinical and radiographic features. Morbidity is high in perinatal stroke, because it accounts for most cases of hemiparetic cerebral palsy, with disability lasting a lifetime. Additional complications include disorders of sensation and vision, language delays, cognitive and learning deficits, epilepsy, and mental health consequences that affect the entire family. Advances in neonatal neurocritical care may afford opportunity to minimize brain injury and improve outcomes. In the chronic timeframe, progress made in neuroimaging and brain mapping is revealing the developmental plasticity that occurs, informing new avenues for neurorehabilitation. This review will summarize the diagnosis and management of each perinatal stroke disease, highlighting their similarities and distinctions and emphasizing a patient- and family-centered approach to management.

Seizures in the neonate: A review of etiologies and outcomes

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

Risk for infantile spasms after acute symptomatic neonatal seizures

OBJECTIVE

Infantile spasms (IS) is a severe epilepsy in early childhood. Early treatment of IS provides the best chance of seizure remission and favorable developmental outcome. We aimed to develop a prediction rule to accurately predict which neonates with acute symptomatic seizures will develop IS.

METHODS

We used data from the Neonatal Seizure Registry, a prospective, multicenter cohort of infants with acute symptomatic neonatal seizures born from July 2015 to March 2018. Neonates with acute symptomatic seizures who received clinical electroencephalography (EEG) and magnetic resonance imaging (MRI) and were younger than 2 years of age at the time of enrollment were included. We evaluated the association of neonatal EEG, MRI, and clinical factors with subsequent IS using bivariate analysis and best subsets logistic regression. We selected a final model through a consensus process that balanced statistical significance with clinical relevance.

RESULTS

IS developed in 12 of 204 infants (6%). Multiple potential predictors were associated with IS, including Apgar scores, EEG features, seizure characteristics, MRI abnormalities, and clinical status at hospital discharge. The final model included three risk factors: (a) severely abnormal EEG or ≥3 days with seizures recorded on EEG, (b) deep gray or brainstem injury on MRI, and (c) abnormal tone on discharge exam. The stratified risk of IS was the following: no factors 0% (0/82, 95% confidence interval [CI] 0%-4%), one or two factors 4% (4/108, 95% CI 1%-9%), and all three factors 57% (8/14, 95% CI 29%-83%).

SIGNIFICANCE

IS risk after acute symptomatic neonatal seizures can be stratified using commonly available clinical data. No child without risk factors, vs >50% of those with all three factors, developed IS. This risk prediction rule may be valuable for clinical counseling as well as for selecting participants for clinical trials to prevent post-neonatal epilepsy. This tailored approach may lead to earlier diagnosis and treatment and improve outcomes for a devastating early life epilepsy.

Linking acute symptomatic neonatal seizures, brain injury and outcome in preterm infants

Neonatal seizures (NS) are the most frequent sign of neurological dysfunction in newborn infants. With increased survival of preterm neonates, the current clinical focus has shifted from preventing death to improving long-term neurological outcome. In the context of acute symptomatic NS, the main negative prognostic factors include etiology, and severity of brain injury, but also prolonged seizures and especially status epilepticus. However, the reasons for the detrimental contribution of seizures to outcome are still unclear, and evidence has been collected both in favor of seizures being an epiphenomenon of brain injury and of independently contributing to further damage. In this narrative focused review, we will discuss both hypotheses, with special emphasis on data relating to preterm infants. We will also identify present controversies and possible future lines of research.

Seizures and Outcome One Year After Neonatal and Childhood Cerebral Sinovenous Thrombosis

BACKGROUND

Pediatric cerebral sinovenous thrombosis is a treatable cause of brain injury, acute symptomatic seizures, and remote epilepsy. Our objective was to prospectively study epilepsy and outcomes in neonates and children one year after cerebral sinovenous thrombosis diagnosis.

METHODS

Patients with cerebral sinovenous thrombosis were enrolled prospectively from 21 international sites through the Seizures in Pediatric Stroke Study. Clinical data, including acute symptomatic seizures and cerebral sinovenous thrombosis risk factors, were collected at diagnosis. A neuroradiologist who was unaware of the diagnosis reviewed acute imaging. At one year, outcomes including seizure recurrence, epilepsy diagnosis, antiepileptic drug use, and modified Engel score were collected. Outcomes were assessed using the modified Rankin score and the King's Outcome Scale for Childhood Head Injury.

RESULTS

Twenty-four participants with cerebral sinovenous thrombosis were enrolled (67% male, 21% neonates). Headache was the most common presenting symptom in non-neonates (47%, nine of 19). Nine (37.5%) presented with acute symptomatic seizures. Six (25%; 95% confidence interval, 10% to 47%) developed epilepsy by one-year follow-up. No clinical predictors associated with epilepsy were identified. King's Outcome Scale for Childhood Head Injury and modified Rankin scores at one year were favorable in 71%. Half of the patients who developed epilepsy (three of six) did not have infarcts, hemorrhage, or seizures identified during the acute hospitalization.

CONCLUSION

Our study provides a prospective estimate that epilepsy occurs in approximately one-quarter of patients by one year after diagnosis of cerebral sinovenous thrombosis. Later epilepsy can develop in the absence of acute seizures or parenchymal injury associated with the acute presentation.

Perinatal Stroke

Perinatal strokes are a diverse but specific group of focal cerebrovascular injuries that occur early in brain development and affect an estimated 5 million people worldwide. The objective of this review is to describe the epidemiology, clinical presentations, pathophysiology, outcomes, and management for the 6 subtypes of perinatal stroke. Some perinatal strokes are symptomatic in the first days of life, typically with seizures, including neonatal arterial ischemic stroke, neonatal hemorrhagic stroke, and cerebral sinovenous thrombosis. The remaining subtypes present in the first year of life or later, usually with motor asymmetry and include arterial presumed perinatal ischemic stroke, presumed perinatal hemorrhagic stroke, and in utero periventricular venous infarction. The consequences of these injuries include cerebral palsy, epilepsy, and cognitive and behavioral challenges, in addition to the psychosocial impact on families. While there have been significant advances in understanding mechanisms of both injury and recovery, there is still a great deal to learn regarding causation and the optimization of outcomes.

Epileptic Spasms Predict Poor Epilepsy Outcomes After Perinatal Stroke

Perinatal stroke is a significant cause of severe epilepsy, including epileptic spasms. Although epileptic spasms due to underlying structural lesion often respond poorly to treatment and evolve into drug-resistant epilepsy, outcomes are not uniformly poor, and predictors of outcomes are not well described. We performed a single-institution retrospective review of epileptic spasms following perinatal stroke to determine if outcome depended on vascular subtype. We identified 24 children with epileptic spasms due to perinatal ischemic stroke: 11 cases of perinatal arterial stroke and 13 cases of perinatal venous infarct. Initial response to treatment was similar between groups; however, although children with perinatal arterial stroke who responded to epileptic spasms therapy had high rates of seizure freedom, many children with perinatal venous infarct, regardless of initial response, had residual drug-resistant epilepsy. We consider whether the mechanism for epileptogenesis may be different between arterial and venous strokes, and whether these 2 groups should be monitored for epileptic spasms, and subsequent epilepsy, differently.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Bedside neurophysiological tests can identify neonates with stroke leading to cerebral palsy

OBJECTIVE

The unspecific symptoms of neonatal stroke still challenge its bedside diagnosis. We studied the accuracy of routine electroencephalography (EEG) and simultaneously recorded somatosensory evoked potentials (EEG-SEP) for diagnosis and outcome prediction of neonatal stroke.

METHODS

We evaluated EEG and EEG-SEPs from a hospital cohort of 174 near-term neonates with suspected seizures or encephalopathy, 32 of whom were diagnosed with acute ischemic or hemorrhagic stroke in MRI. EEG was scored for background activity and seizures. SEPs were classified as present or absent. Developmental outcome of stroke survivors was evaluated from medical records at 8- to 18-months age.

RESULTS

The combination of continuous EEG and uni- or bilaterally absent SEP (n = 10) was exclusively seen in neonates with a middle cerebral artery (MCA) stroke (specificity 100%). Moreover, 80% of the neonates with this finding developed with cerebral palsy. Bilaterally present SEPs did not exclude stroke, but predicted favorable neuromotor outcome in stroke survivors (positive predictive value 95%).

CONCLUSIONS

Absent SEP combined with continuous EEG background in near-term neonates indicates an MCA stroke and a high risk for cerebral palsy.

SIGNIFICANCE

EEG-SEP offers a bedside method for diagnostic screening and a reliable prediction of neuromotor outcome in neonates suspected of having a stroke.

Incidence of Epilepsy and Associated Risk Factors in Perinatal Ischemic Stroke Survivors

INTRODUCTION

Epilepsy is a serious and often lifelong consequence of perinatal arterial ischemic stroke (PAIS). Variable incidences and risk factors for long-term epilepsy in PAIS have been reported. To determine the incidence of epilepsy in PAIS survivors and report factors associated with the risk of developing epilepsy, a meta-analysis and systematic review of prior publications was performed.

METHODS

We examined studies on perinatal or neonatal patients (≤28 days of life) with arterial ischemic strokes in which the development of epilepsy was reported. EMBASE and MEDLINE/PubMed databases were systematically searched in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses.

RESULTS

A meta-analysis of 10 studies revealed a summary incidence of epilepsy in PAIS patients of 27.2% (95% confidence interval 16.6% to 41.4%) over a mean study duration of 10.4 years (range 1.5 to 17). More recent studies generally reported a lower epilepsy incidence. A systematic review identified seven possible risk factors for epilepsy in PAIS patients: hippocampal volume reduction, infarct on prenatal ultrasound, a modified Alberta Stroke Program Early Computed Tomography score ≥9, family history of seizures, cerebral palsy, and initial presentation with cognitive impairment or seizures.

CONCLUSIONS

About a third of children with PAIS will develop epilepsy. While seven possible risk factors have been reported, further research is warranted to confirm the strength of their association with the development of epilepsy.

A Model of Perinatal Ischemic Stroke in the Rat: 20 Years Already and What Lessons?

Neonatal hypoxia-ischemia (HI) and ischemia are a common cause of neonatal brain injury resulting in cerebral palsy with subsequent learning disabilities and epilepsy. Recent data suggest a higher incidence of focal ischemia-reperfusion located in the middle cerebral artery (MCA) territory in near-term and newborn babies. Pre-clinical studies in the field of cerebral palsy research used, and still today, the classical HI model in the P7 rat originally described by Rice et al. (1). At the end of the 90s, we designed a new model of focal ischemia in the P7 rat to explore the short and long-term pathophysiology of neonatal arterial ischemic stroke, particularly the phenomenon of reperfusion injury and its sequelae (reported in 1998). Cerebral blood-flow and cell death/damage correlates have been fully characterized. Pharmacologic manipulations have been applied to the model to test therapeutic targets. The model has proven useful for the study of seizure occurrence, a clinical hallmark for neonatal ischemia in babies. Main pre-clinical findings obtained within these 20 last years are discussed associated to clinical pattern of neonatal brain damage.

Perinatal stroke: mechanisms, management, and outcomes of early cerebrovascular brain injury

Perinatal stroke encompasses a heterogeneous group of focal neurological injuries early in brain development that probably affects more than 5 million people worldwide. Many such injuries are symptomatic in the first days of life, including neonatal arterial ischaemic stroke, cerebral sinovenous thrombosis, and neonatal haemorrhagic stroke. The remaining focal neurological injuries usually present later in the first year with motor asymmetry, such as arterial presumed perinatal ischaemic stroke, periventricular venous infarction, and presumed perinatal haemorrhagic stroke. The numerous sequelae of these injuries include hemiparesis (cerebral palsy), epilepsy, and cognitive, language, and behavioural challenges. In this Review we summarise each perinatal stroke disease, examining the epidemiology, pathophysiology, acute management, and outcomes, including the effect on parents and families, and emerging therapies to mitigate these lifelong morbidities.

Conventional MRI scan and DTI imaging show more severe brain injury in neonates with hypoxic-ischemic encephalopathy and seizures

BACKGROUND

Neonates with hypoxic-ischemic encephalopathy (HIE) and seizures have poorer outcome for undetermined reasons.

AIMS

Our aim was to determine if brain imaging was more abnormal in neonates with HIE and electrographically confirmed seizures and whether this was impacted by seizure burden.

STUDY DESIGN

Single center retrospective review.

SUBJECTS

Forty-eight term neonates with HIE (with and without seizures) underwent MRI brain scans before age 14 days between the years 2008 and 2013.

OUTCOME MEASURES

Images were rated using a MRI injury score and fractional anisotropy (FA) values were extracted from diffusion tensor imaging (DTI).

RESULTS

The seizure group (n = 25) had significantly more injury within white matter, basal ganglia, posterior limb of internal capsule, and watershed areas compared to the group without seizures (n = 23). The severity of injury in all measured areas increased with increasing seizure severity. The seizure group also had lower FA values in posterior limb of the internal capsule and the splenium of corpus callosum.

CONCLUSIONS

Neonates with HIE and seizures had more brain injury that occurred in areas typically affected by HIE and was greater with higher seizure burden. Seizures may be a marker of more severe brain injury or seizures themselves may amplify brain damage from HIE.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Outcomes after acute symptomatic seizures in neonates

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

Outcomes following electrographic seizures and electrographic status epilepticus in the pediatric and neonatal ICUs

PURPOSE OF REVIEW

Increasing recognition of electrographic seizures and electrographic status epilepticus in critically ill neonates and children has highlighted the importance of identifying their potential contributions to neurological outcomes to guide optimal management.

RECENT FINDINGS

Recent studies in children and neonates have found an independent association between increasing seizure burden and worse short-term and long-term outcomes, even after adjusting for other important contributors to outcome such as seizure cause and illness severity. The risk of worse neurological outcome has been shown to increase above a seizure burden threshold of 12-13 min/h, which is considerably lower than the conventional definition of status epilepticus of 30 min/h. Randomized controlled trials in neonates have demonstrated that electroencephalography-targeted therapy can successfully reduce seizure burden, but due to their small size these trials have not been able to demonstrate that more aggressive electroencephalography-targeted treatment of both subclinical and clinical seizures results in improved outcome.

SUMMARY

Despite mounting evidence for an independent association between increasing seizure burden and worse outcome, further study is needed to determine whether early seizure identification and aggressive antiseizure treatment can improve neurodevelopmental outcomes.

Seizure Severity Is Correlated With Severity of Hypoxic-Ischemic Injury in Abusive Head Trauma

BACKGROUND

The objective of this study was to characterize hypoxic-ischemic injury and seizures in abusive head trauma.

METHODS

We studied 58 children with moderate or severe traumatic brain injury due to abusive head trauma. Continuous electroencephalograms and magnetic resonance images were scored.

RESULTS

Electrographic seizures (51.2%) and hypoxic-ischemic injury (77.4%) were common in our cohort. Younger age was associated with electrographic seizures (no seizures: median age 13.5 months, interquartile range five to 25 months, versus seizures: 4.5 months, interquartile range 3 to 9.5 months; P = 0.001). Severity of hypoxic-ischemic injury was also associated with seizures (no seizures: median injury score 1.0, interquartile range 0 to 3, versus seizures: 4.5, interquartile range 3 to 8; P = 0.01), but traumatic injury severity was not associated with seizures (no seizures: mean injury score 3.78 ± 1.68 versus seizures: mean injury score 3.83 ± 0.95, P = 0.89). There was a correlation between hypoxic-ischemic injury severity and seizure burden when controlling for patient age (r_s=0.61, P < 0.001). The ratio of restricted diffusion volume to total brain volume (restricted diffusion ratio) was smaller on magnetic resonance imaging done early (median restricted diffusion ratio 0.03, interquartile range 0 to 0.23 on magnetic resonance imaging done within two days versus median restricted diffusion ratio 0.13, interquartile range 0.01 to 0.43 on magnetic resonance imaging done after two days, P = 0.03).

CONCLUSIONS

Electrographic seizures are common in children with moderate to severe traumatic brain injury from abusive head trauma, and therefore children with suspected abusive head trauma should be monitored with continuous electroencephalogram. Severity of hypoxic-ischemic brain injury is correlated with severity of seizures, and evidence of hypoxic-ischemic injury on magnetic resonance imaging may evolve over time. Therefore children with a high seizure burden should be reimaged to evaluate for evolving hypoxic-ischemic injury.

EEG findings and outcomes of continuous video-EEG monitoring started prior to initiation of seizure treatment in the perinatal stroke

BACKGROUND

To analyze the findings in the background EEG activity of infants who suffered perinatal stroke.

METHODS

Eleven neonates born 2009-2014 diagnosed of ischemic stroke by MRI (three of them with multistroke) underwent continuous video-EEG monitoring. Visual and spectral (power spectrum and coherence) analyses of the background EEG was performed in three moments: 1) Onset of EEG recording (prior to initiate seizure treatment), 2) Post-ictal epoch (1-2 h after the last seizure), and 3) one-two days after seizure control. All children aged 2-6 years underwent neurodevelopmental assessment.

RESULTS

Discontinuity, asymmetry, asynchrony, transients, and relative power spectrum in δ and θ frequency bands increased significantly (p < 0.05) in the post-ictal epoch with respect to onset of EEG recording. After seizure control, discontinuity, asynchrony, and θ power spectrum no longer had significant differences with those found at onset of EEG recording. Significant differences between the ischemic and unaffected hemispheres were found in transients and in β coherence (p = 0.002; p = 0.001, respectively) exclusively in the post-ictal epoch. Seizure burden and time-to-control ranged 5-38 min and 0.5-40 h respectively. Currently, only one child is affected by spastic monoparesis. The intelligence quotients ranged 96-123.

CONCLUSIONS

The background EEG can undergo significant changes in the post-ictal epoch due to the seizure activity triggered by the perinatal stroke. Most of these EEG changes involve all brain activity and not exclusively the ischemic hemisphere. Many of these modifications in the EEG background reverse following the seizure control. Video-EEG monitoring allows accurate/immediate diagnosis and rapid/intensive treatment of the stroke-associated seizures.

Epilepsy after perinatal stroke with different vascular subtypes

Objective

With an incidence up to 63 per 100,000 live births, perinatal stroke is an important cause of childhood epilepsy. The aim of the study was to find the prevalence of and predictive factors for epilepsy, and to describe the course of epilepsy in children with perinatal stroke with different vascular subtypes.

Methods

Patients were retrieved from the Estonian Paediatric Stroke Database with follow‐up time at least 24 months. Patients were divided into 5 perinatal stroke syndromes: neonatal arterial ischemic stroke (AIS), neonatal hemorrhagic stroke, neonatal cerebral sinovenous thrombosis, presumed AIS, and presumed periventricular venous infarction.

Results

The final study group included 73 children with perinatal stroke (39 boys). With a median follow‐up time of 8.6 years, epilepsy was diagnosed in 21/73 (29%) children, most of whom had AIS (17/21, 81%). The 18‐year cumulative poststroke epilepsy risk according to the Kaplan‐Meier estimator was 40.8% (95% confidence interval [CI] 20.7–55.9%). The median age at epilepsy diagnosis was 50 months (range 1 month to 18.4 years). Children with neonatal AIS had the highest risk of epilepsy, but children with presumed AIS more often had severe epilepsy syndromes. Cortical lesions (odds ratio [OR] 19.7, 95% CI 2.9–133), and involvement of thalamus (OR 9.8, 95% CI 1.8–53.5) and temporal lobe (OR 8.3, 95% CI 1.8–39.6) were independently associated with poststroke epilepsy.

Significance

The risk for poststroke epilepsy after perinatal stroke depends on the vascular subtype. Patients with perinatal AIS need close follow‐up to detect epilepsy and start with antiepileptic treatment on time.

Non-Invasive Brain Stimulation in Children With Unilateral Cerebral Palsy: A Protocol and Risk Mitigation Guide

Non-invasive brain stimulation has been increasingly investigated, mainly in adults, with the aims of influencing motor recovery after stroke. However, a consensus on safety and optimal study design has not been established in pediatrics. The low incidence of reported major adverse events in adults with and without clinical conditions has expedited the exploration of NIBS in children with paralleled purposes to influence motor skill development after neurological injury. Considering developmental variability in children, with or without a neurologic diagnosis, adult dosing and protocols may not be appropriate. The purpose of this paper is to present recommendations and tools for the prevention and mitigation of adverse events (AEs) during NIBS in children with unilateral cerebral palsy (UCP). Our recommendations provide a framework for pediatric NIBS study design. The key components of this report on NIBS AEs are (a) a summary of related literature to provide the background evidence and (b) tools for anticipating and managing AEs from four international pediatric laboratories. These recommendations provide a preliminary guide for the assessment of safety and risk mitigation of NIBS in children with UCP. Consistent reporting of safety, feasibility, and tolerability will refine NIBS practice guidelines contributing to future clinical translations of NIBS.

A 15-year epileptogenic period after perinatal brain injury

Seizures are a frequent acute neurological event in the neonatal period. Up to 12 to 18% of all seizures in newborns are due to perinatal stroke and up to 39% of affected children can then develop epilepsy in childhood. We report the case of a young patient who presented stroke-related seizures in the neonatal period and then developed focal symptomatic epilepsy at 15 years of age, and in whom the epileptic focus was found to co-localize with the site of his ischemic brain lesion. Such a prolonged silent period before onset of remote symptomatic epilepsy has not previously been reported. This case suggests that newborns with seizures due to a neonatal stroke are at higher risk of epilepsy and that the epileptogenic process in these subjects can last longer than a decade.

Prolonged or recurrent acute seizures after pediatric arterial ischemic stroke are associated with increasing epilepsy risk

AIM

To determine epilepsy risk factors after pediatric stroke.

METHOD

A cohort of children with arterial ischemic stroke (birth-18y) was enrolled at 21 centers and followed for 1 year. Acute seizures (≤7d after stroke) and active epilepsy (at least one unprovoked remote seizure plus maintenance anticonvulsant at 1y) were identified. Predictors were determined using logistic regression.

RESULTS

Among 114 patients (28 neonates and 86 children) enrolled, 26 neonates (93%) and 32 children (37%) had an acute seizure. Acute seizures lasted longer than 5 minutes in 23 patients (40%) and were frequently recurrent: 33 (57%) had 2 to 10 seizures and 11 (19%) had more than 10. Among 109 patients with 1-year follow-up, 11 (10%) had active epilepsy. For each year younger, active epilepsy was 20% more likely (odds ratio [OR] 0.8, 95% confidence interval [CI] 0.6-0.99, p=0.041). Prolonged or recurrent acute seizures also increased epilepsy risk. Each additional 10 minutes of the longest acute seizure increased epilepsy risk fivefold (OR 4.7, 95% CI 1.7-13). Patients with more than 10 acute seizures had a 30-fold increased epilepsy risk (OR 30, 95% CI 2.9-305).

INTERPRETATION

Pediatric stroke survivors, especially younger children, have a high risk of epilepsy 1 year after stroke. Prolonged or recurrent acute seizures increase epilepsy risk in a dose-dependent manner.

Different response to antiepileptic drugs according to the type of epileptic events in a neonatal ischemia-reperfusion model

Perinatal arterial stroke is the most frequent form of cerebral infarction in children. Neonatal seizures are the most frequent symptom during the neonatal period. The current management of perinatal stroke is based on supportive care. It is currently unknown if treatment of the seizures modifies the outcome, and no clinical studies have focused on seizures during neonatal stroke. We studied the effect of phenobarbital and levetiracetam on an ischemic-reperfusion stroke model in P7 rats using prolonged electroencephalographic recordings and a histologic analysis of the brain (24h after injury). The following two types of epileptic events were observed: 1) bursts of high amplitude spikes during ischemia and the first hours of reperfusion and 2) organized seizures consisting in discharges of a 1-2Hz spike-and-wave. Both phenobarbital and levetiracetam decreased the total duration of the bursts of high amplitude spikes. Phenobarbital also delayed the start of seizures without changing the total duration of epileptic discharges. The markedly limited efficacy of the antiepileptic drugs studied in our neonatal stroke rat model is frequently observed in human neonatal seizures. Both drugs did not modify the stroke volume, which suggests that the modification of the quantity of bursts of high amplitude spikes does not influence the infarct size. In the absence of a reduction in seizure burden by the antiepileptic drugs, we increased the seizure burden and stroke volume by combining our neonatal stroke model with a lithium-pilocarpine-induced status epilepticus. Our data suggest that the reduction of burst of spikes did not influence the stroke volume. The presence of organized seizure with a pattern close to what is observed in human newborns seems related to the presence of the infarct. Further research is required to determine the relationship between seizure burden and infarct volume.

Risk of Remote Seizures After Perinatal Ischemic Stroke

Investigators from the University of California San Francisco and Kaiser Permanente Medical Centers in Oakland report outcome of perinatal arterial ischemic stroke (PAIS) in a population-based cohort, with particular attention to the incidence of seizures.