Ictal-Interictal Continuum in the Pediatric Intensive Care Unit.

BACKGROUND: The ictal-interictal continuum (IIC) consists of several electroencephalogram (EEG) patterns that are common in critically ill adults. Studies focused on the IIC are limited in critically ill children and have focused primarily on associations with electrographic seizures (ESs). We report the incidence of the IIC in the pediatric intensive care unit (PICU). We then compare IIC patterns to rhythmic and periodic patterns (RPP) not meeting IIC criteria looking for associations with acute cerebral abnormalities, ES, and in-hospital mortality. METHODS: This was a retrospective review of prospectively collected data for patients admitted to the PICU at Children's National Hospital from July 2021 to January 2023 with continuous EEG. We excluded patients with known epilepsy and cerebral injury prior to presentation. All patients were screened for RPP. The American Clinical Neurophysiology Society standardized Critical Care EEG terminology for the IIC was applied to each RPP. Associations between IIC and RPP not meeting IIC criteria, with clinical and EEG variables, were calculated using odds ratios (ORs). RESULTS: Of 201 patients, 21% (42/201) had RPP and 12% (24/201) met IIC criteria. Among patients with an IIC pattern, the median age was 3.4 years (interquartile range (IQR) 0.6-12 years). Sixty-seven percent (16/24) of patients met a single IIC criterion, whereas the remainder met two criteria. ESs were identified in 83% (20/24) of patients and cerebral injury was identified in 96% (23/24) of patients with IIC patterns. When comparing patients with IIC patterns with those with RPP not qualifying as an IIC pattern, both patterns were associated with acute cerebral abnormalities (IIC OR 26 [95% confidence interval {CI} 3.4-197], p = 0.0016 vs. RPP OR 3.5 [95% CI 1.1-11], p = 0.03), however, only the IIC was associated with ES (OR 121 [95% CI 33-451], p < 0.0001) versus RPP (OR 1.3 [0.4-5], p = 0.7). CONCLUSIONS: Rhythmic and periodic patterns and subsequently the IIC are commonly seen in the PICU and carry a high association with cerebral injury. Additionally, the IIC, seen in more than 10% of critically ill children, is associated with ES. The independent impact of RPP and IIC patterns on secondary brain injury and need for treatment of these patterns independent of ES requires further study.

Background EEG Suppression Ratio for Early Detection of Cerebral Injury in Pediatric Cardiac Arrest.

BACKGROUND: Our objective was to assess the utility of the 1-h suppression ratio (SR) as a biomarker of cerebral injury and neurologic prognosis after cardiac arrest (CA) in the pediatric hospital setting. METHODS: Prospectively, we reviewed data from children presenting after CA and monitored by continuous electroencephalography (cEEG). Patients aged 1 month to 21 years were included. The SR, a quantitative measure of low-voltage cEEG (≤ 3 µV) content, was dichotomized as present or absent if there was > 0% suppression for one continuous hour. A multivariate logistic regression analysis was performed including age, sex, type of CA (i.e., in-hospital or out-of-hospital), and the presence of SR as a predictor of global anoxic cerebral injury as confirmed by magnetic resonance imaging (MRI). RESULTS: We included 84 patients with a median age of 4 years (interquartile range 0.9-13), 64% were male, and 49% (41/84) had in-hospital CA. Cerebral injury was seen in 50% of patients, of whom 65% had global injury. One-hour SR presence, independent of amount, predicted cerebral injury with 81% sensitivity (95% confidence interval (CI) (66-91%) and 98% specificity (95% CI 88-100%). Multivariate logistic regression analyses indicated that SR was a significant predictor of both cerebral injury (ß = 6.28, p < 0.001) and mortality (ß = 3.56, p < 0.001). CONCLUSIONS: The SR a sensitive and specific marker of anoxic brain injury and post-CA mortality in the pediatric population. Once detected in the post-CA setting, the 1-h SR may be a useful threshold finding for deployment of early neuroprotective strategies prior or for prompting diagnostic neuroimaging.

Neuromonitoring in Children with Cerebrovascular Disorders.

BACKGROUND: Cerebrovascular disorders are an important cause of morbidity and mortality in children. The acute care of a child with an ischemic or hemorrhagic stroke or cerebral sinus venous thrombosis focuses on stabilizing the patient, determining the cause of the insult, and preventing secondary injury. Here, we review the use of both invasive and noninvasive neuromonitoring modalities in the care of pediatric patients with arterial ischemic stroke, nontraumatic intracranial hemorrhage, and cerebral sinus venous thrombosis. METHODS: Narrative review of the literature on neuromonitoring in children with cerebrovascular disorders. RESULTS: Neuroimaging, near-infrared spectroscopy, transcranial Doppler ultrasonography, continuous and quantitative electroencephalography, invasive intracranial pressure monitoring, and multimodal neuromonitoring may augment the acute care of children with cerebrovascular disorders. Neuromonitoring can play an essential role in the early identification of evolving injury in the aftermath of arterial ischemic stroke, intracranial hemorrhage, or sinus venous thrombosis, including recurrent infarction or infarct expansion, new or recurrent hemorrhage, vasospasm and delayed cerebral ischemia, status epilepticus, and intracranial hypertension, among others, and this, is turn, can facilitate real-time adjustments to treatment plans. CONCLUSIONS: Our understanding of pediatric cerebrovascular disorders has increased dramatically over the past several years, in part due to advances in the neuromonitoring modalities that allow us to better understand these conditions. We are now poised, as a field, to take advantage of advances in neuromonitoring capabilities to determine how best to manage and treat acute cerebrovascular disorders in children.

The Spectrum of Quantitative EEG Utilization Across North America: A Cross-Sectional Survey.

BACKGROUND: Continuous electroencephalography (cEEG) is commonly used for neuromonitoring in pediatric intensive care units (PICU); however, there are barriers to real-time interpretation of EEG data. Quantitative EEG (qEEG) transforms the EEG signal into time-compressed graphs, which can be displayed at the bedside. A survey was designed to understand current PICU qEEG use. METHODS: An electronic survey was sent to the Pediatric Neurocritical Care Research Group and Pediatric Status Epilepticus Research Group, and intensivists in 16 Canadian PICUs. Questions addressed demographics, qEEG acquisition and storage, clinical use, and education. RESULTS: Fifty respondents from 39 institutions completed the survey (response rate 53% [39 of 74 institutions]), 76% (37 of 50) from the United States and 24% (12 of 50) from Canada. Over half of the institutions (22 of 39 [56%]) utilize qEEG in their ICUs. qEEG use was associated with having a neurocritical care (NCC) service, ≥200 NCC consults/year, ≥1500 ICU admissions/year, and ≥4 ICU EEGs/day (P < 0.05 for all). Nearly all users (92% [24 of 26]) endorsed that qEEG enhanced care of children with acute neurological injury. Lack of training in qEEG was identified as a common barrier [85% (22 of 26)]. Reviewing and reporting of qEEG was not standard at most institutions. Training was required by 14% (three of 22) of institutions, and 32% (seven of 22) had established curricula. CONCLUSIONS: ICU qEEG was used at more than half of the institutions surveyed, but review, reporting, and application of this tool remained highly variable. Although providers identify qEEG as a useful tool in patient management, further studies are needed to define clinically meaningful pediatric trends, standardize reporting, and enhance educate bedside providers.

Sporadic and Periodic Interictal Discharges in Critically Ill Children: Seizure Associations and Time to Seizure Identification.

PURPOSE: We evaluated interictal discharges (IEDs) as a biomarker for the time to development of electrographic seizures (ES). METHODS: Prospective observational study of 254 critically ill children who underwent continuous electroencephalography (cEEG) monitoring. We excluded neonates and patients with known epilepsy or the sole cEEG indication to characterize events. Interictal discharges included sporadic epileptiform discharges and periodic and rhythmic patterns. Sporadic epileptiform discharges were categorized as low frequency (rare [<1/hour] and occasional [≥1/hour but <1/minute]) and high frequency (frequent, [≥1/minute] and abundant [≥1/10 seconds]). Time variables included time from cEEG start to first IED and time between first IED and ES. RESULTS: Interictal discharges were present in 33% (83/254) of patients. We identified ES in 20% (50/254), and 86% (43/50) had IEDs. High-frequency sporadic epileptiform discharges (odds ratio [OR], 35; 95% confidence interval [CI], 14.5-88; P < 0.0001) and lateralized periodic discharges (OR, 27; 95% CI, 7.3-100; P < 0.0001) were associated with ES. Mildly abnormal EEG background without IEDs or background asymmetry was associated with the absence of seizures (OR, 0.1; 95% CI, 0.04-0.3; P < 0.0001). Time from cEEG start to first IED was 36 minutes (interquartile range, 3-131 minutes), and time between first IED and ES was 9.6 minutes (interquartile range, 0.6-165 minutes). CONCLUSIONS: Interictal discharges are associated with ES and are identified in the first 3 hours of cEEG. High-frequency sporadic epileptiform discharges and periodic patterns have the highest risk of ES. Our findings define a window of high seizure risk after the identification of IEDs in which to allocate resources to improve seizure identification and subsequent treatment.

Continuous Video Electroencephalography (EEG) for Event Characterization in Critically Ill Children.

OBJECTIVE: To determine features of paroxysmal events and background electroencephalographic (EEG) abnormalities associated with electroclinical seizures in critically ill children who undergo continuous video EEG to characterize clinical events. METHODS: This is a prospective study of critically ill children from July 2016 to October 2018. Non-neonates with continuous video EEG indication to characterize a clinical event were included. Patients with continuous video EEG to assess for subclinical seizures due to unexplained encephalopathy and those whose event of concern were not captured on continuous video EEG were excluded. The event to be characterized was taken from documented descriptions of health care providers and classified as motor, ocular, orobuccal, autonomic, and other. In patients with more than 1 component to their paroxysmal event, the events were classified as motor plus and nonmotor plus. RESULTS: One hundred patients met inclusion and exclusion criteria, with electroclinical seizures captured in 30% (30/100). The most common event to be characterized was an autonomic event in 32% (32/100). Asymmetry and epileptiform discharges were associated with electroclinical seizures (odds ratio [OR] 2.7, 95% confidence interval [CI] 1.1-6.5, P = .03; and OR 12.5, 95% CI 4.4-35.6, P < .0001). Autonomic events alone, particularly unexplained vital sign changes, were not associated with electroclinical seizures (OR 0.3, 95% CI 0.11-0.93, P = .03). CONCLUSIONS: Isolated autonomic events are unlikely to be electroclinical seizures. Details of the paroxysmal events in question can help decide which patient will benefit most from continuous video EEG based on institutional resources.

Quantitative Electroencephalography for Early Detection of Elevated Intracranial Pressure in Critically Ill Children: Case Series and Proposed Protocol.

OBJECTIVE: To describe quantitative EEG (electroencephalography) suppression ratio in children with increased intracranial pressure comparing acute suppression ratio changes to imaging and/or examination findings. METHODS: We retrospectively reviewed the suppression ratio from patients with neuroimaging and /or examination findings of increased intracranial pressure while on continuous EEG. The time of the first change in the suppression ratio was compared to the time of the first image and/or examination change confirming increased intracranial pressure. RESULTS: Thirteen patients with a median age of 3.1 years(interquartile range 1.8-6.3) had a rise in the suppression ratio with median time from identification to acute neuroimaging or examination of increased intracranial pressure of 3.12 hours (interquartile range 2.2-33.5) after the first increase in the suppression ratio. CONCLUSIONS: Acute suppression ratio increase is seen prior to imaging and/or examination findings of increased intracranial pressure. With further study, the suppression ratio can be targeted with intracranial pressure-lowering agents to prevent morbidity and mortality associated with increased intracranial pressure.

EEG features of brain injury during extracorporeal membrane oxygenation in children.

OBJECTIVE: To examine EEG features of major pathophysiology in children undergoing extracorporeal membrane oxygenation (ECMO). METHODS: This was a single-center, retrospective study of 201 pediatric patients on ECMO, using the first 24 hours of continuous EEG (cEEG) monitoring, collating background activity and electrographic seizures (ES) with imaging, ECMO type, and outcome. RESULTS: Severely abnormal cEEG background occurred in 12% (25/201), and was associated with death (sensitivity 0.23, specificity 0.97). ES occurred in 16% (33/201) within 3.2 (0.6-20.3) hours (median [interquartile range]) of cEEG commencement, and higher ES burden was associated with death. ES was always associated with ipsilateral injury (p = 0.006), but occurred in only one-third of cases with abnormal imaging. In 28 patients with isolated hemisphere lesion, type of arterial ECMO cannulation was associated with side of injury: right carotid cannulation was associated with right hemisphere lesions, and ascending aorta cannulation with left hemisphere lesions (odds ratio, 0.29 [95% confidence interval, 0.08-0.98], p = 0.03). CONCLUSIONS: After starting ECMO, cEEG background activity has the potential to inform prognosis. Type of arterial (carotid vs aortic) ECMO correlates with side of focal cerebral injury, which in ≈33% is associated with presence of ES. We hypothesize that the differential distribution reflects abnormal flow dynamics or embolic injury.

Posterior-onset Rasmussen's encephalitis with ipsilateral cerebellar atrophy and uveitis resistant to rituximab.

Rasmussen encephalitis (RE) is a disorder characterized by drug-resistant seizures and progressive unihemispheric atrophy, hemiparesis, and varying degrees of cognitive decline. The pathophysiology of RE remains elusive, with hypotheses suggesting underlying autoimmune- and T cell-mediated processes. In this case report, we describe a single patient's clinical course from the first day of presentation until definitive treatment for atypical Rasmussen encephalitis at a tertiary care pediatric center. The patient exhibited several atypical features of Rasmussen encephalitis, including a posterior predominance of initial seizure onset with the development of severe choreoathetosis and ipsilateral cerebellar atrophy. He subsequently developed coexistent autoimmune disorders in the form of psoriasis and uveitis, and underwent multiple forms of immunotherapy with limited benefit. This patient shows an association of RE with other autoimmune conditions supporting an autoimmune mechanism of disease while exhibiting several atypical features of RE. Rarely, occipital lobe seizures have been documented as the presenting semiology of this syndrome. This case highlights the need to be mindful of atypical features that may delay hemispherectomy, which remains the definitive treatment. It also suggests that children may be predisposed to the development of autoimmune disorders in later stages of the disease.

Interleukin-6 Blockade With Tocilizumab in Anakinra-Refractory Febrile Infection-Related Epilepsy Syndrome (FIRES).

Febrile infection-related epilepsy syndrome (FIRES) is characterized by new onset refractory status epilepticus in a previously healthy child that is associated with poor cognitive outcomes and chronic epilepsy. Innate immune system dysfunction is hypothesized to be a key etiologic contributor, with a potential role for immunotherapy blocking pro-inflammatory cytokines, such as interleukin-1ß and interleukin-6. We present a case of FIRES refractory to anakinra, an interleukin-1 receptor antagonist, subsequently treated with the ketogenic diet and tocilizumab, an interleukin-6 receptor antagonist, temporally associated with seizure cessation and a favorable 1-year outcome.

Electroencephalographic Reporting for Refractory Status Epilepticus.

PURPOSE: We aimed to determine whether clinical EEG reports obtained from children in the intensive care unit with refractory status epilepticus could provide data for comparative effectiveness research studies. METHODS: We conducted a retrospective descriptive study to assess the documentation of key variables within clinical continuous EEG monitoring reports based on the American Clinical Neurophysiology Society's standardized EEG terminology for children with refractory status epilepticus from 10 academic centers. Two pediatric electroencephalographers reviewed the EEG reports. We compared reports generated using free text or templates. RESULTS: We reviewed 191 EEG reports. Agreement between the electroencephalographers regarding whether a variable was described in the report ranged from fair to very good. The presence of electrographic seizures (ES) was documented in 46% (87/191) of reports, and these reports documented the time of first ES in 64% (56/87), ES duration in 72% (63/85), and ES frequency in 68% (59/87). Reactivity was documented in 16% (31/191) of reports, and it was more often documented in template than in free-text reports (40% vs. 14%, P = 0.006). Other variables were not differentially reported in template versus free-text reports. CONCLUSIONS: Many key EEG features are not documented consistently in clinical continuous EEG monitoring reports, including ES characteristics and reactivity assessment. Standardization may be needed for clinical EEG reports to provide informative data for large multicenter observational studies.

Seizure Prediction Models in the Neonatal Intensive Care Unit.

PURPOSE: Conventional video-EEG monitoring is required to diagnose seizures accurately in neonates. This tool is resource-intense and has limited availability in many centers. Seizure prediction models could help allocate resources by improving efficiency in which conventional video-EEG monitoring is used to detect subclinical seizures. The aim of this retrospective study was to create a neonate-specific seizure prediction model using clinical characteristics and EEG background findings. METHODS: We conducted a 3-year retrospective study of all consecutive neonates who underwent conventional video-EEG monitoring at a tertiary care pediatric hospital. Variables including age, EEG indication, high-risk clinical characteristics, and EEG background informed seizure prediction models based on a multivariable logistic regression model. A Cox proportional hazard regression model was used to construct time to first EEG seizure. RESULTS: Prediction models with clinical variables or background EEG features alone versus combined clinical and background EEG features were created from 210 neonates who met inclusion criteria. The combined clinical and EEG model had a higher area under the curve for combined sensitivity and specificity to 83.0% when compared to the clinical model (76.4%) or EEG model (66.2%). The same trend of higher sensitivity of the combined model was found for time to seizure outcome. CONCLUSIONS: While both clinical and EEG background features were predictive of neonatal seizures, the combination improved overall prediction of seizure occurrence and prediction of time to first seizure as compared with prediction models based solely on clinical or EEG features alone. With prospective validation, this model may improve efficiency of patient-oriented EEG monitoring.

Conventional and quantitative EEG in status epilepticus.

PURPOSE: To summarize the use of continuous electroencephalographic monitoring (cEEG) in the diagnosis and management of pediatric convulsive status epilepticus (CSE) and subsequent non-convulsive seizures (NCS) with a focus on available guidelines and infrastructure. In addition, we provide an overview of quantitative EEG (QEEG) for the identification of NCS in critically ill children. METHODS: We performed a review of the medical literature on the use of cEEG and QEEG in pediatric CSE. This included published guideline, consensus statements, and literature focused on the use of cEEG and QEEG to detect NCS. RESULTS: cEEG monitoring is recommended for prompt recognition of ongoing seizures that may be subtle, masked by pharmacologic paralysis, and or converted from convulsive seizures to NCS after administration of anti-seizure medications. Evidence indicating that high seizure burden is associated with worse outcome has motivated prompt recognition and management of NCS. The American Clinical Neurophysiology Society's consensus statement recommends a minimum of 24 h to exclude electrographic seizures, while the Neurocritical Care Society's guideline suggests 48 h in patients that are comatose. The use of QEEG amongst electroencephalographers and critical care medicine providers is increasing for NCS detection in critically ill children. The sensitivity and specificity of QEEG to detect NCS ranges from 65 to 83% and 65-92%, respectively. CONCLUSION: The use of cEEG is important to the diagnosis and treatment of NCS or subtle clinical seizures after pediatric CSE. QEEG allows cEEG data to be reviewed and interpreted quickly and is a useful tool for detection of NCS after CSE.

Machine Learning for Outcome Prediction in Electroencephalograph (EEG)-Monitored Children in the Intensive Care Unit.

The aim of this study was to evaluate the performance of models predicting in-hospital mortality in critically ill children undergoing continuous electroencephalography (cEEG) in the intensive care unit (ICU). We evaluated the performance of machine learning algorithms for predicting mortality in a database of 414 critically ill children undergoing cEEG in the ICU. The area under the receiver operating characteristic curve (AUC) in the test subset was highest for stepwise selection/elimination models (AUC = 0.82) followed by least absolute shrinkage and selection operator (LASSO) and support vector machine with linear kernel (AUC = 0.79), and random forest (AUC = 0.71). The explanatory models had the poorest discriminative performance (AUC = 0.63 for the model without considering etiology and AUC = 0.45 for the model considering etiology). Using few variables and a relatively small number of patients, machine learning techniques added information to explanatory models for prediction of in-hospital mortality.

Post-arrest therapeutic hypothermia in pediatric patients with congenital heart disease.

BACKGROUND: While therapeutic hypothermia (TH) is an effective neuroprotective therapy for neonatal hypoxic-ischemic encephalopathy, TH has not been demonstrated to improve outcome in other pediatric populations. Patients with acquired or congenital heart disease (CHD) are at high risk of both cardiac arrest and neurodevelopmental impairments, and therapies are needed to improve neurologic outcome. The primary goal of our study was to compare safety/efficacy outcomes in post-arrest CHD patients treated with TH versus controls not treated with TH. METHODS: Patients with CHD treated during the first 18 months after initiation of a post-arrest TH protocol (temperature goal: 33.5 °C) were compared to historical and contemporary post-arrest controls not treated with TH. Post-arrest data, including temperature, safety measures (e.g. arrhythmia, bleeding), neurodiagnostic data (EEG, neuroimaging), and survival were compared. RESULTS: Thirty arrest episodes treated with TH and 51 control arrest episodes were included. The groups did not differ in age, duration of arrest, post-arrest lactate, or use of ECMO-CPR. The TH group's post-arrest temperature was significantly lower than control's (33.6 ±â€¯0.2 °C vs 34.7 ±â€¯0.5 °C, p < 0.001). There was no difference between the groups in safety/efficacy measures, including arrhythmia, infections, chest-tube output, or neuroimaging abnormalities, nor in hospital survival (TH 61.5% vs control 59.1%, p = NS). Significantly more controls had seizures than TH patients (26.1% vs. 4.0%, p = 0.04). Almost all seizures were subclinical and occurred more than 24 h post-arrest. CONCLUSION: Our data show that pediatric CHD patients who suffer cardiac arrest can be treated effectively and safely with TH, which may decrease the incidence of seizures.

Time to continuous electroencephalogram in repeated admissions to the pediatric intensive care unit.

PURPOSE: Describe timing from intensive care unit (ICU) admission to initiation of continuous electroencephalogram (cEEG) in repeated ICU admissions. METHOD: We performed a retrospective observational study in pediatric patients who underwent repeated ICU admissions with cEEG from 2011 to 2013. The main outcome measure was time from ICU admission to cEEG. RESULTS: There were 41 patients (54% males) with at least 2 ICU admissions with cEEG (median (p25-p75) age at first admission: 3.3 (0.3-8.4) years, at second admission: 3.9 (1.1-9.4) years), 7 patients (57% males, 9.9 (2.9-11.5) years) with at least 3 ICU admissions, and 5 patients (60% males, 10.1 (4-10.5) years) with at least 4 ICU admissions. One patient had 21 ICU admissions. The median (p25-p75) time from ICU admission to cEEG was not different during the first and second ICU admissions [10.7 (1.9-22.9) hours versus 13 (0.2-36.7) hours; p=0.908]. Among patients with electrographic seizures on first admission, time to cEEG was not different during the first and second admissions [7.9 (0.5-23.4) hours versus 14.5 (-2 to 44.5) hours; p=0.636]. Among patients with status epilepticus during the first admission, time to cEEG was not different between the first and second admissions [15.3 (9-79) hours versus 40.7 (19.3-42.6) hours; p=0.75]. CONCLUSIONS: The time from ICU admission to the initiation of cEEG did not decrease in second or subsequent ICU admissions, even in patients with seizures or status epilepticus on the first admission.

Electrographic Seizures in Preterm Neonates in the Neonatal Intensive Care Unit.

OBJECTIVE: Characterize clinical and electroencephalography (EEG) characteristics of preterm neonates undergoing continuous EEG in the neonatal intensive care unit. METHODS: Retrospective study of preterm neonates born less than 37 weeks' gestational age undergoing continuous EEG in the neonatal intensive care unit at Boston Children's Hospital over a 2-year period. RESULTS: Fifty-two preterms (46% male) had a mean gestational age of 32.8 weeks (standard deviation = 4.17). Seizures were detected in 12/52 (23%), with EEG seizures detected in 4/12 (33%). The median time from EEG to the first seizure was 0.5 hours (interquartile range 0.24-4). Factors associated with seizures were male gender (odds ratio = 4.65 [95% confidence interval = 1.02-21.24], P = .047) and lack of EEG state change (odds ratio = 0.043 [95% confidence interval = 0.005-0.377], P = .04). CONCLUSION: Twenty-three percent of preterms undergoing continuous EEG had EEG seizures or electrographic seizures with no clear clinical correlate. This confirms recent American Clinical Neurophysiology Society guidelines suggesting that preterm neonates are at high risk for seizures.

Diagnostic and Therapeutic Management of a First Unprovoked Seizure in Children and Adolescents With a Focus on the Revised Diagnostic Criteria for Epilepsy.

By definition, unprovoked seizures are not precipitated by an identifiable factor, such as fever or trauma. A thorough history and physical examination are essential to caring for pediatric patients with a potential first unprovoked seizure. Differential diagnosis, EEG, neuroimaging, laboratory tests, and initiation of treatment will be reviewed. Treatment is typically initiated after 2 unprovoked seizures, or after 1 seizure in select patients with distinct epilepsy syndromes. Recent expansion of the definition of epilepsy by the ILAE allows for the diagnosis of epilepsy to be made after the first seizure if the clinical presentation and supporting diagnostic studies suggest a greater than 60% chance of a second seizure. This review summarizes the current literature on the diagnostic and therapeutic management of first unprovoked seizure in children and adolescents while taking into consideration the revised diagnostic criteria of epilepsy.

Continuous EEG in Pediatric Critical Care: Yield and Efficiency of Seizure Detection.

PURPOSE: Our goal was to define the duration of continuous EEG (cEEG) monitoring needed to adequately capture electrographic seizures and EEG status epilepticus in the pediatric intensive care unit using clinical and background EEG features. METHODS: Retrospective study of patients aged 1 month to 21 years admitted to a tertiary pediatric intensive care unit and undergoing cEEG (>3 hours). Clinical data collected included admission diagnosis, EEG background features, and time variables including time to first seizure after initiation of cEEG. RESULTS: Four hundred fourteen patients aged 4.2 (0.75-11.3) years (median, interquartile range) were included. With a median duration of 21 (16-42.2) hours of cEEG monitoring, we identified electrographic seizure or EEG status epilepticus in 25% of subjects. We identified three features that could improve the efficiency of cEEG resources and provide a decision-making framework: (1) clinical history of acute encephalopathy is not predictive of detecting electrographic seizure or EEG status epilepticus, whereas a history of status epilepticus or seizures is; (2) normal EEG background or absence of epileptiform discharges in the initial 24 hours of recording informs the decision to discontinue cEEG; (3) failure to record electrographic ictal events within the first 4 to 6 hours of monitoring may be sufficient to predict the absence of subsequent ictal events. CONCLUSIONS: Individualized monitoring plans are necessary to increase seizure detection yield while improving resource utilization. A strategy using information from the clinical history, initial EEG background, and the first 4 to 6 hours of recording may be effective in determining the necessary duration of cEEG monitoring in the pediatric intensive care unit.

Time to electroencephalography is independently associated with outcome in critically ill neonates and children.

OBJECTIVE: To identify factors associated with in-hospital mortality in neonates and children undergoing continuous electroencephalography (cEEG) monitoring in the intensive care unit (ICU). METHODS: We performed a retrospective observational study in patients from birth to 21 years of age who underwent clinically indicated cEEG in the ICU from 2011 to 2013. The main outcome measure was in-hospital mortality. RESULTS: Six-hundred and twenty-five patients (54.2% male) met eligibility criteria, of whom 211 were neonates (55% male, 24.8% premature) and 414 were pediatric patients (53.9% male). Electrographic seizures occurred in 176 patients (28.2%) and status epilepticus (SE) occurred in 20 (11.4%). The time from ICU admission to cEEG initiation was 16.7 (5.1-94.4) h. Eighty-nine patients (14.2%) (30 [14.2%] neonates, and 59 [14.3%] pediatric patients) died in the hospital. In neonates-after controlling for gender and prematurity-independent factors associated with mortality were prematurity (odds ratio [OR] 2.63. 95% confidence interval [CI] 1.06-6.5, p = 0.037), presence of status epilepticus (SE); OR 8.82, 95% CI 1.74-44.57, p = 0.008), and time from ICU admission to initiation of cEEG (OR 1.002, 95% CI 1.001-1.004 per hour, p = 0.008]. In pediatric patients-after controlling for gender and age-independent factors associated with mortality were the absence of seizures factors associated with mortality were absence of seizures (OR = 4.3, (95% CI: 1.5-12.4), p = 0.007), the presence of SE (OR 7.76, 95% CI 1.47-40.91, p = 0.016), and the time from ICU admission to initiation of cEEG (OR 1.001, 95% CI 1.0002-1.001, per hour, p = 0.005]. SIGNIFICANCE: Both presence of electrographic SE and time from ICU admission to cEEG initiation were independent factors associated with mortality in neonates and pediatric patients with cEEG in the ICU.