Simulation-based Inference of Developmental EEG Maturation with the Spectral Graph Model.

The spectral content of macroscopic neural activity evolves throughout development, yet how this maturation relates to underlying brain network formation and dynamics remains unknown. Here, we assess the developmental maturation of electroencephalogram spectra via Bayesian model inversion of the spectral graph model, a parsimonious whole-brain model of spatiospectral neural activity derived from linearized neural field models coupled by the structural connectome. Simulation-based inference was used to estimate age-varying spectral graph model parameter posterior distributions from electroencephalogram spectra spanning the developmental period. This model-fitting approach accurately captures observed developmental electroencephalogram spectral maturation via a neurobiologically consistent progression of key neural parameters: long-range coupling, axonal conduction speed, and excitatory:inhibitory balance. These results suggest that the spectral maturation of macroscopic neural activity observed during typical development is supported by age-dependent functional adaptations in localized neural dynamics and their long-range coupling across the macroscopic structural network.

Relationship of Neonatal Seizure Burden Before Treatment and Response to Initial Antiseizure Medication.

OBJECTIVE: To assess among a cohort of neonates with hypoxic-ischemic encephalopathy (HIE) the association of pretreatment maximal hourly seizure burden and total seizure duration with successful response to initial antiseizure medication (ASM). STUDY DESIGN: This was a retrospective review of data collected from infants enrolled in the HEAL Trial (NCT02811263) between January 25, 2017, and October 9, 2019. We evaluated a cohort of neonates born at ≥36 weeks of gestation with moderate-to-severe HIE who underwent continuous electroencephalogram monitoring and had acute symptomatic seizures. Poisson regression analyzed associations between (1) pretreatment maximal hourly seizure burden, (2) pretreatment total seizure duration, (3) time from first seizure to initial ASM, and (4) successful response to initial ASM. RESULTS: Among 39 neonates meeting inclusion criteria, greater pretreatment maximal hourly seizure burden was associated with lower chance of successful response to initial ASM (adjusted relative risk for each 5-minute increase in seizure burden 0.83, 95% CI 0.69-0.99). There was no association between pretreatment total seizure duration and chance of successful response. Shorter time-to-treatment was paradoxically associated with lower chance of successful response to treatment, although this difference was small in magnitude (relative risk 1.007, 95% CI 1.003-1.010). CONCLUSIONS: Maximal seizure burden may be more important than other, more commonly used measures in predicting response to acute seizure treatments.

A quantitative EEG index for the recognition of arterial ischemic stroke in children.

OBJECTIVE: To describe and assess performance of the Correlate Of Injury to the Nervous system (COIN) index, a quantitative electroencephalography (EEG) metric designed to identify areas of cerebral dysfunction concerning for stroke. METHODS: Case-control study comparing continuous EEG data from children with acute ischemic stroke to children without stroke, with or without encephalopathy. COIN is calculated continuously and compares EEG power between cerebral hemispheres. Stroke relative infarct volume (RIV) was calculated from quantitative neuroimaging analysis. Significance was determined using a two-sample t-test. Sensitivity, specificity, and accuracy were measured using logistic regression. RESULTS: Average COIN values were -34.7 in the stroke cohort compared to -9.5 in controls without encephalopathy (p = 0.003) and -10.5 in controls with encephalopathy (p = 0.006). The optimal COIN cutoff to discriminate stroke from controls was -15 in non-encephalopathic and -18 in encephalopathic controls with >92% accuracy in strokes with RIV > 5%. A COIN cutoff of -20 allowed discrimination between strokes with <5% and >5% RIV (p = 0.027). CONCLUSIONS: We demonstrate that COIN can identify children with acute ischemic stroke. SIGNIFICANCE: COIN may be a valuable tool for stroke identification in children. Additional studies are needed to determine utility as a monitoring technique for children at risk for stroke.

Association of EEG Background and Neurodevelopmental Outcome in Neonates With Hypoxic-Ischemic Encephalopathy Receiving Hypothermia.

BACKGROUND AND OBJECTIVES: Predicting neurodevelopmental outcome for neonates with hypoxic-ischemic encephalopathy (HIE) is important for clinical decision-making, care planning, and parent communication. We examined the relationship between EEG background and neurodevelopmental outcome among children enrolled in a trial of erythropoietin or placebo for neonates with HIE treated with therapeutic hypothermia. METHODS: Participants had EEG recorded throughout hypothermia. EEG background was classified as normal, discontinuous, or severely abnormal (defined as burst suppression, low voltage suppressed, or status epilepticus) at 5 1-hour epochs: onset of recording, 24, 36, 48, and 72 hours after birth. The predominant background pattern during the entire continuous video EEG monitoring recording was calculated using the arithmetic mean of the 5 EEG background ratings (normal = 0; discontinuous = 1; severely abnormal = 2) as follows: "predominantly normal" (mean = 0), "normal/discontinuous" (0 < mean<1), "predominantly discontinuous" (mean = 1), "discontinuous/severely abnormal" (1 < mean<2), or "predominantly severely abnormal" (mean = 2). Primary outcome was death or neurodevelopmental impairment (NDI) defined as cerebral palsy, Gross Motor Function Classification Score ≥1, or cognitive score <90 on Bayley Scales of Infant Toddler Development, third edition at age 2 years. Neurodevelopment was also categorized into a 5-level ordinal measure: no, mild, moderate, severe NDI, or death for secondary analysis. We used generalized linear regression models with robust standard errors to assess the relative risk of death or NDI by EEG background in both unadjusted and adjusted analyses controlling for the effects of treatment group, sex, HIE severity, and study recruitment site. RESULTS: Among 142 neonates, the predominant background EEG pattern was predominantly normal in 35 (25%), normal/discontinuous in 68 (48%), predominantly discontinuous in 11 (7.7%), discontinuous/severely abnormal in 16 (11%), and predominantly severely abnormal in 12 (8.5%). Increasing severity of background across monitoring epochs was associated with increasingly worse clinical outcomes. Children with severe EEG background abnormality at any time point (n = 36, 25%) were significantly more likely to die or have severe NDI at 2 years (adjusted relative risk: 7.95, 95% CI 3.49-18.12). DISCUSSION: EEG background is strongly associated with NDI at age 2 years. These results can be used to assist health care providers to plan follow-up care and counsel families for decision-making related to goals of care.

Neonatal brain MRI and short-term outcomes after acute provoked seizures.

OBJECTIVE: We investigated how diagnosis and injury location on neonatal brain MRI following onset of acute provoked seizures was associated with short term outcome. STUDY DESIGN: A multicenter cohort of neonates with acute provoked seizures enrolled in the Neonatal Seizure Registry. MRIs were centrally evaluated by a neuroradiologist for location of injury and radiologic diagnosis. Clinical outcomes were determined by chart review. Multivariate logistic regression was used to examine the association between MRI findings and outcomes. RESULTS: Among 236 newborns with MRI at median age 4 days (IQR 3-8), 91% had abnormal MRI. Radiologic diagnoses of intracranial hemorrhage (OR 3.2 [1.6-6.5], p < 0.001) and hypoxic-ischemic encephalopathy (OR 2.7 [1.4-5.4], p < 0.003) were associated with high seizure burden. Radiologic signs of intracranial infection were associated with abnormal neurologic examination at discharge (OR 3.9 [1.3-11.6], p < 0.01). CONCLUSION: Findings on initial MRI can help with expectant counseling on short-term outcomes following acute provoked neonatal seizures.

Association of High-Dose Erythropoietin With Circulating Biomarkers and Neurodevelopmental Outcomes Among Neonates With Hypoxic Ischemic Encephalopathy: A Secondary Analysis of the HEAL Randomized Clinical Trial.

Importance: The ability to predict neurodevelopmental impairment (NDI) for infants diagnosed with hypoxic ischemic encephalopathy (HIE) is important for parental guidance and clinical treatment as well as for stratification of patients for future neurotherapeutic studies. Objectives: To examine the effect of erythropoietin on plasma inflammatory mediators in infants with moderate or severe HIE and to develop a panel of circulating biomarkers that improves the projection of 2-year NDI over and above the clinical data available at the time of birth. Design, Setting, and Participants: This study is a preplanned secondary analysis of prospectively collected data from infants enrolled in the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) Trial, which tested the efficacy of erythropoietin as an adjunctive neuroprotective therapy to therapeutic hypothermia. The study was conducted at 17 academic sites comprising 23 neonatal intensive care units in the United States between January 25, 2017, and October 9, 2019, with follow-up through October 2022. Overall, 500 infants born at 36 weeks' gestation or later with moderate or severe HIE were included. Intervention: Erythropoietin treatment 1000 U/kg/dose on days 1, 2, 3, 4 and 7. Main Outcomes and Measures: Plasma erythropoietin was measured in 444 infants (89%) within 24 hours after birth. A subset of 180 infants who had plasma samples available at baseline (day 0/1), day 2, and day 4 after birth and either died or had 2-year Bayley Scales of Infant Development III assessments completed were included in the biomarker analysis. Results: The 180 infants included in this substudy had a mean (SD) gestational age of 39.1 (1.5) weeks, and 83 (46%) were female. Infants who received erythropoietin had increased concentrations of erythropoietin at day 2 and day 4 compared with baseline. Erythropoietin treatment did not alter concentrations of other measured biomarkers (eg, difference in interleukin [IL] 6 between groups on day 4: -1.3 pg/mL; 95% CI, -4.8 to 2.0 pg/mL). After adjusting for multiple comparisons, we identified 6 plasma biomarkers (C5a, interleukin [IL] 6, and neuron-specific enolase at baseline; IL-8, tau, and ubiquitin carboxy-terminal hydrolase-L1 at day 4) that significantly improved estimations of death or NDI at 2 years compared with clinical data alone. However, the improvement was only modest, increasing the AUC from 0.73 (95% CI, 0.70-0.75) to 0.79 (95% CI, 0.77-0.81; P = .01), corresponding to a 16% (95% CI, 5%-44%) increase in correct classification of participant risk of death or NDI at 2 years. Conclusions and Relevance: In this study, erythropoietin treatment did not reduce biomarkers of neuroinflammation or brain injury in infants with HIE. Circulating biomarkers modestly improved estimation of 2-year outcomes. Trial Registration: ClinicalTrials.gov Identifier: NCT02811263.

Responsive Neurostimulation in Drug-Resistant Pediatric Epilepsy: Findings From the Epilepsy Surgery Subgroup of the Pediatric Epilepsy Research Consortium.

BACKGROUND: Responsive neurostimulation (RNS), a closed-loop intracranial electrical stimulation system, is a palliative surgical option for patients with drug-resistant epilepsy (DRE). RNS is approved by the US Food and Drug Administration for patients aged ≥18 years with pharmacoresistant partial seizures. The published experience of RNS in children is limited. METHODS: This is a combined prospective and retrospective study of patients aged ≤18 years undergoing RNS placement. Patients were identified from the multicenter Pediatric Epilepsy Research Consortium Surgery Registry from January 2018 to December 2021, and additional data relevant to this study were retrospectively collected and analyzed. RESULTS: Fifty-six patients received RNS during the study period. The mean age at implantation was 14.9 years; the mean duration of epilepsy, 8.1 years; and the mean number of previously trialed antiseizure medications, 4.2. Five patients (9%) previously trialed dietary therapy, and 19 patients (34%) underwent prior surgery. Most patients (70%) underwent invasive electroencephalography evaluation before RNS implantation. Complications occurred in three patients (5.3%) including malpositioned leads or transient weakness. Follow-up (mean 11.7 months) was available for 55 patients (one lost), and four were seizure-free with RNS off. Outcome analysis of stimulation efficacy was available for 51 patients: 33 patients (65%) were responders (≥50% reduction in seizure frequency), including five patients (10%) who were seizure free at follow-up. CONCLUSIONS: For young patients with focal DRE who are not candidates for surgical resection, neuromodulation should be considered. Although RNS is off-label for patients aged <18 years, this multicenter study suggests that it is a safe and effective palliative option for children with focal DRE.

Risk of seizures in neonates with hypoxic-ischemic encephalopathy receiving hypothermia plus erythropoietin or placebo.

BACKGROUND: An ancillary study of the High-Dose Erythropoietin for Asphyxia and Encephalopathy (HEAL) trial for neonates with hypoxic-ischemic encephalopathy (HIE) and treated with therapeutic hypothermia examined the hypothesis that neonates randomized to receive erythropoietin (Epo) would have a lower seizure risk and burden compared with neonates who received placebo. METHODS: Electroencephalograms (EEGs) from 7/17 HEAL trial centers were reviewed. Seizure presence was compared across treatment groups using a logistic regression model adjusting for treatment, HIE severity, center, and seizure burden prior to the first dose. Among neonates with seizures, differences across treatment groups in median maximal hourly seizure burden were assessed using adjusted quantile regression models. RESULTS: Forty-six of 150 (31%) neonates had EEG seizures (31% in Epo vs 30% in placebo, p = 0.96). Maximal hourly seizure burden after the study drug was not significantly different between groups (median 11.4 for Epo, IQR: 5.6, 18.1 vs median 9.7, IQR: 4.9, 21.0 min/h for placebo). CONCLUSION: In neonates with HIE treated with hypothermia who were randomized to Epo or placebo, we found no meaningful between-group difference in seizure risk or burden. These findings are consistent with overall trial results, which do not support Epo use for neonates with HIE undergoing therapeutic hypothermia. IMPACT: In the HEAL trial of erythropoietin (Epo) vs placebo for neonates with encephalopathy presumed due to hypoxic-ischemic encephalopathy (HIE) who were also treated with therapeutic hypothermia, electrographic seizures were detected in 31%, which is lower than most prior studies. Epo did not reduce the proportion of neonates with acute provoked seizures (31% in Epo vs 30% in placebo) or maximal hourly seizure burden after the study drug (median 11.4, IQR 5.6, 18.1 for Epo vs median 9.7, IQR 4.9, 21.0 min/h for placebo). There was no anti- or pro-convulsant effect of Epo when combined with therapeutic hypothermia for HIE.

Seizure Burden, EEG, and Outcome in Neonates With Acute Intracranial Infections: A Prospective Multicenter Cohort Study.

BACKGROUND: Limited data exist regarding seizure burden, electroencephalogram (EEG) background, and associated outcomes in neonates with acute intracranial infections. METHODS: This secondary analysis was from a prospective, multicenter study of neonates enrolled in the Neonatal Seizure Registry with seizures due to intracranial infection. Sites used continuous EEG monitoring per American Clinical Neurophysiology Society guidelines. High seizure burden was defined a priori as seven or more EEG-confirmed seizures. EEG background was categorized using standardized terminology. Primary outcome was neurodevelopment at 24-months corrected age using Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS). Secondary outcomes were postneonatal epilepsy and motor disability. RESULTS: Twenty-seven of 303 neonates (8.9%) had seizures due to intracranial infection, including 16 (59.3%) bacterial, 5 (18.5%) viral, and 6 (22.2%) unknown. Twenty-three neonates (85%) had at least one subclinical seizure. Among 23 children with 24-month follow-up, the WIDEA-FS score was, on average, 23 points lower in children with high compared with low seizure burden (95% confidence interval, [-48.4, 2.1]; P = 0.07). After adjusting for gestational age, infection etiology, and presence of an additional potential acute seizure etiology, the effect size remained unchanged (ß = -23.8, P = 0.09). EEG background was not significantly associated with WIDEA-FS score. All children with postneonatal epilepsy (n = 4) and motor disability (n = 5) had high seizure burden, although associations were not significant. CONCLUSION: High seizure burden may be associated with worse neurodevelopment in neonates with intracranial infection and seizures. EEG monitoring can provide useful management and prognostic information in this population.

Inequities in Therapy for Infantile Spasms: A Call to Action.

OBJECTIVE: The aim of this study was to determine whether selection of treatment for children with infantile spasms (IS) varies by race/ethnicity. METHODS: The prospective US National Infantile Spasms Consortium database includes children with IS treated from 2012 to 2018. We examined the relationship between race/ethnicity and receipt of standard IS therapy (prednisolone, adrenocorticotropic hormone, vigabatrin), adjusting for demographic and clinical variables using logistic regression. Our primary outcome was treatment course, which considered therapy prescribed for the first and, when needed, the second IS treatment together. RESULTS: Of 555 children, 324 (58%) were non-Hispanic white, 55 (10%) non-Hispanic Black, 24 (4%) non-Hispanic Asian, 80 (14%) Hispanic, and 72 (13%) other/unknown. Most (398, 72%) received a standard treatment course. Insurance type, geographic location, history of prematurity, prior seizures, developmental delay or regression, abnormal head circumference, hypsarrhythmia, and IS etiologies were associated with standard therapy. In adjusted models, non-Hispanic Black children had lower odds of receiving a standard treatment course compared with non-Hispanic white children (odds ratio [OR], 0.42; 95% confidence interval [CI], 0.20-0.89; p = 0.02). Adjusted models also showed that children with public (vs. private) insurance had lower odds of receiving standard therapy for treatment 1 (OR, 0.42; CI, 0.21-0.84; p = 0.01). INTERPRETATION: Non-Hispanic Black children were more often treated with non-standard IS therapies than non-Hispanic white children. Likewise, children with public (vs. private) insurance were less likely to receive standard therapies. Investigating drivers of inequities, and understanding the impact of racism on treatment decisions, are critical next steps to improve care for patients with IS. ANN NEUROL 2022;92:32-44.

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.

Disorders of Neuronal Migration/Organization Convey the Highest Risk of Neonatal Onset Epilepsy Compared With Other Congenital Brain Malformations.

BACKGROUND: Although seizures in neonates are common and often due to acute brain injury, 10-15% are unprovoked from congenital brain malformations. A better understanding of the risk of neonatal-onset epilepsy by the type of brain malformation is essential for counseling and monitoring. METHODS: In this retrospective cohort study, we evaluated 132 neonates with congenital brain malformations and their risk of neonatal-onset epilepsy. Malformations were classified into one of five categories based on imaging patterns on prenatal or postnatal imaging. Infants were monitored with continuous video EEG (cEEG) for encephalopathy and paroxysmal events in addition to abnormal neuroimaging. RESULTS: Seventy-four of 132 (56%) neonates underwent EEG monitoring, and 18 of 132 (14%) were diagnosed with neonatal-onset epilepsy. The highest prevalence of epilepsy was in neonates with disorders of neuronal migration/organization (9/34, 26%; 95% confidence interval [CI] = 13-44%), followed by disorders of early prosencephalic development (6/38, 16%; 95% CI = 6-31%), complex total brain malformations (2/16, 13%; 95% CI = 2-38%), and disorders of midbrain/hindbrain malformations (1/30, 3%; 95% CI = 0-17%). Of neonates with epilepsy, 5 of 18 (28%) had only electrographic seizures, 13 of 18 (72%) required treatment with two or more antiseizure medicines (ASMs), and 7 of 18 (39%) died within the neonatal period. CONCLUSION: Our results demonstrate that disorders of neuronal migration/organization represent the highest-risk group for early-onset epilepsy. Seizures are frequently electrographic only, require treatment with multiple ASMs, and portend a high mortality rate. These results support American Clinical Neurophysiology Society recommendations for EEG monitoring during the neonatal period for infants with congenital brain malformations.

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.

Neonatal presentation of genetic epilepsies: Early differentiation from acute provoked seizures.

OBJECTIVE: Although most seizures in neonates are due to acute brain injury, some represent the first sign of neonatal onset genetic epilepsies. Delay in recognition and lack of expert assessment of neonates with epilepsy may result in worse developmental outcomes. As in older children and adults, seizure semiology in neonates is an essential determinant in diagnosis. We aimed to establish whether seizure type at presentation in neonates can suggest a genetic etiology. METHODS: We retrospectively analyzed the clinical and electroencephalographic (EEG) characteristics of seizures in neonates admitted in two Level IV neonatal intensive care units, diagnosed with genetic epilepsy, for whom a video-EEG recording at presentation was available for review, and compared them on a 1:2 ratio with neonates with seizures due to stroke or hypoxic-ischemic encephalopathy. RESULTS: Twenty neonates with genetic epilepsy were identified and compared to 40 neonates with acute provoked seizures. Genetic epilepsies were associated with pathogenic variants in KCNQ2 (n = 12), KCNQ3 (n = 2), SCN2A (n = 2), KCNT1 (n = 1), PRRT2 (n = 1), and BRAT1 (n = 2). All neonates with genetic epilepsy had seizures with clinical correlates that were either tonic (18/20) or myoclonic (2/20). In contrast, 17 of 40 (42%) neonates with acute provoked seizures had electrographic only seizures, and the majority of the remainder had clonic seizures. Time to first seizure was longer in neonates with genetic epilepsies (median = 60 h of life) compared to neonates with acute provoked seizures (median = 15 h of life, p < .001). Sodium channel-blocking antiseizure medications were effective in 13 of 14 (92%) neonates with tonic seizures who were trialed at onset or during the course of the epilepsy. SIGNIFICANCE: Seizure semiology is an easily accessible sign of genetic epilepsies in neonates. Early identification of the seizure type can prompt appropriate workup and treatment. Tonic seizures are associated with channelopathies and are often controlled by sodium channel-blocking antiseizure medications.

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

Importance: Antiseizure medication (ASM) treatment duration for acute symptomatic neonatal seizures is variable. A randomized clinical trial of phenobarbital compared with placebo after resolution of acute symptomatic seizures closed early owing to low enrollment. Objective: To assess whether ASM discontinuation after resolution of acute symptomatic neonatal seizures and before hospital discharge is associated with functional neurodevelopment or risk of epilepsy at age 24 months. Design, Setting, and Participants: This comparative effectiveness study included 303 neonates with acute symptomatic seizures (282 with follow-up data and 270 with the primary outcome measure) from 9 US Neonatal Seizure Registry centers, born from July 2015 to March 2018. The centers all had level IV neonatal intensive care units and comprehensive pediatric epilepsy programs. Data were analyzed from June 2020 to February 2021. Exposures: The primary exposure was duration of ASM treatment dichotomized as ASM discontinued vs ASM maintained at the time of discharge from the neonatal seizure admission. To enhance causal association, each outcome risk was adjusted for propensity to receive ASM at discharge. Propensity for ASM maintenance was defined by a logistic regression model including seizure cause, gestational age, therapeutic hypothermia, worst electroencephalogram background, days of electroencephalogram seizures, and discharge examination (all P ≤ .10 in a joint model except cause, which was included for face validity). Main Outcomes and Measures: Functional neurodevelopment was assessed by the Warner Initial Developmental Evaluation of Adaptive and Functional Skills (WIDEA-FS) at 24 months powered for propensity-adjusted noninferiority of early ASM discontinuation. Postneonatal epilepsy, a prespecified secondary outcome, was defined per International League Against Epilepsy criteria, determined by parent interview, and corroborated by medical records. Results: Most neonates (194 of 303 [64%]) had ASM maintained at the time of hospital discharge. Among 270 children evaluated at 24 months (mean [SD], 23.8 [0.7] months; 147 [54%] were male), the WIDEA-FS score was similar for the infants whose ASMs were discontinued (101 of 270 [37%]) compared with the infants with ASMs maintained (169 of 270 [63%]) at discharge (median score, 165 [interquartile range, 150-175] vs 161 [interquartile range, 129-174]; P = .09). The propensity-adjusted average difference was 4 points (90% CI, -3 to 11 points), which met the a priori noninferiority limit of -12 points. The epilepsy risk was similar (11% vs 14%; P = .49), with a propensity-adjusted odds ratio of 1.5 (95% CI, 0.7-3.4; P = .32). Conclusions and Relevance: In this comparative effectiveness study, no difference was found in functional neurodevelopment or epilepsy at age 24 months among children whose ASM was discontinued vs maintained at hospital discharge after resolution of acute symptomatic neonatal seizures. These results support discontinuation of ASM prior to hospital discharge for most infants with acute symptomatic neonatal seizures.

Seizure and Interictal Electroencephalographic (EEG) Changes with Cannabinoid Concentrate Use.

BACKGROUND The electroencephalographic (EEG) findings associated with tetrahydrocannabinol (THC) use, particularly in concentrated form, are not well-described, despite the current widespread availability of these products. There is a lack of prior research describing the EEG findings in adolescent cannabis users, and the effects of THC on the seizure threshold have been variably reported. CASE REPORT A 17-year-old girl with no prior history of seizures or known seizure risk factors presented to an Emergency Department with acutely abnormal behavior in the setting of daily vaping of highly concentrated THC marijuana ("wax"). On admission, she had a witnessed generalized tonic-clonic seizure. Urine toxicology was positive for THC, and an extensive evaluation for other etiologies of her encephalopathy was unrevealing. Extended EEG on admission showed mild diffuse background slowing with occasional bifronto-centrally predominant sharp and spike wave discharges. Seven days later, without interim antiseizure medications, a repeat extended EEG showed resolution of the previously seen interictal findings. CONCLUSIONS The clinical and EEG findings were temporally associated with the patient's use of concentrated THC and may represent a constellation of symptoms of a THC wax toxidrome. In this case, THC was associated with lowering the seizure threshold and triggering a provoked seizure in an adolescent with no prior evidence of seizure tendency. This case also suggests the possibility of THC concentrate itself generating epileptiform discharges, as has previously been described with synthetic cannabinoid use.

Comparison of multiplex cytokine assays in a pediatric cohort with epilepsy.

BACKGROUND: Multiplex analyses allow for detection of dozens of cytokines/chemokines in small sample volumes. Although several commercially available assay kits are available, there are no comparative data in plasma measurements among pediatric or epilepsy cohorts. NEW METHOD: Cohort study of 38 children with epilepsy. We evaluated plasma levels of cytokines/chemokines using three different assays: Luminex® xMAP high-sensitivity (HS) and standard-sensitivity (SS) assays, and Meso-Scale Discovery (MSD). We calculated recovery rates of each analyte, correlation coefficients between assays, and level of agreement between measurements. We repeated analyses in a subset of samples after a single freeze-thaw cycle. RESULTS: Among ten analytes common to all assays, HS had high recovery (<15% of values extrapolated or out-of- range [OOR]) for all analytes, SS for 50%, and MSD for 40%. While several analytes had a high correlation between assays, Bland-Altman plots demonstrated assays were not interchangeable. For most analytes, a single freeze-thaw cycle decreased cytokines/chemokine measurements. There was good correlation of measurements after a freeze-thaw cycle with acceptable agreement between measurements for six of 13 (46%) analytes using HS, one of 9 (11%) for SS, and none for MSD. COMPARISON WITH EXISTING METHODS: HS assays may optimize yield in plasma for proteins of particular interest in epilepsy research, limit values extrapolated beyond the standard curve, and improve precision compared to other SS and MSD assays. CONCLUSION: Our results demonstrate assay choice may be critical to study results and support the need for a standardized approach to biomarker assessment across epilepsy research and other domains.

Potential induction of epileptic spasms by nonselective voltage-gated sodium channel blockade: Interaction with etiology.

PURPOSE: Epileptic spasms are often preceded by focal (or multifocal) seizures. Based on a series of case reports suggesting that carbamazepine and oxcarbazepine may induce epileptic spasms, we set out to rigorously evaluate the potential association between exposure to voltage-gated sodium channel blockade and latency to epileptic spasms. METHODS: We identified 50 cases (children with focal seizures and evolution to epileptic spasms) and 50 controls (children with focal seizures without evolution to epileptic spasms). For each patient, we reviewed all sequential neurology encounters between onset of epilepsy and emergence of epileptic spasms. For each encounter we recorded seizure-frequency and all anti-seizure therapy exposures. Using multivariable Cox proportional hazards regression, we evaluated the association between voltage-gated sodium channel exposure (carbamazepine, oxcarbazepine, lacosamide, or phenytoin) and latency to epileptic spasms onset, with adjustment for etiology and seizure-frequency. RESULTS: Latency to epileptic spasms onset was independently associated with exposure to sodium channel blockade (hazard ratio = 2.4; 95% CI 1.1-5.2; P = 0.03) and high-risk etiology (hazard ratio = 2.8; 95% CI 1.5-5.1; P = 0.001). With assessment for interaction between sodium channel blockade and etiology, we identified an estimated 7-fold increased risk of epileptic spasms with the combination of sodium channel blockade and high-risk etiology (hazard ratio = 7.0, 95% CI 2.5-19.8; P < 0.001). CONCLUSION: This study suggests that voltage-gated sodium channel blockade may induce epileptic spasms among children at risk on the basis of etiology. Further study is warranted to replicate these findings, ascertain possible drug- and dose-specific risks, and identify potential mechanisms of harm.