Neuroprognostication after pediatric cardiac arrest

BACKGROUND

Management decisions and parental counseling after pediatric cardiac arrest depend on the ability of physicians to make accurate and timely predictions regarding neurological recovery. We evaluated neurologists and intensivists performing neuroprognostication after cardiac arrest to determine prediction agreement, accuracy, and confidence.

METHODS

Pediatric neurologists (n = 10) and intensivists (n = 9) reviewed 18 cases of children successfully resuscitated from a cardiac arrest and managed in the pediatric intensive care unit. Cases were sequentially presented (after arrest day 1, days 2-4, and days 5-7), with updated examinations, neurophysiologic data, and neuroimaging data. At each time period, physicians predicted outcome by Pediatric Cerebral Performance Category and specified prediction confidence.

RESULTS

Predicted discharge Pediatric Cerebral Performance Category versus actual hospital discharge Pediatric Cerebral Performance Category outcomes were compared. Exact (Predicted Pediatric Cerebral Performance Category - Actual Pediatric Cerebral Performance Category = 0) and close (Predicted Pediatric Cerebral Performance Category - Actual Pediatric Cerebral Performance Category = ±1) outcome prediction accuracies for all physicians improved over successive periods (P < 0.05). Prediction accuracy did not differ significantly between physician groups at any period or overall. Agreement improved over time among neurologists (day 1 Kappa [κ], 0.28; days 2-4 κ, 0.43; days 5-7 κ, 0.68) and among intensivists (day 1 κ, 0.30; days 2-4 κ, 0.44; days 5-7 κ, 0.57). Prediction confidence increased over time (P < 0.001) and did not differ between physician groups.

CONCLUSIONS

Inter-rater agreement among neurologists and among intensivists improved over time and reached moderate levels. For all physicians, prediction accuracy and confidence improved over time. Further prospective research is needed to better characterize how physicians objectively and subjectively estimate neurological recovery after acute brain injury.

Development and validation of a seizure prediction model in critically ill children

PURPOSE

Electrographic seizures are common in encephalopathic critically ill children, but identification requires continuous EEG monitoring (CEEG). Development of a seizure prediction model would enable more efficient use of limited CEEG resources. We aimed to develop and validate a seizure prediction model for use among encephalopathic critically ill children.

METHOD

We developed a seizure prediction model using a retrospectively acquired multi-center database of children with acute encephalopathy without an epilepsy diagnosis, who underwent clinically indicated CEEG. We performed model validation using a separate prospectively acquired single center database. Predictor variables were chosen to be readily available to clinicians prior to the onset of CEEG and included: age, etiology category, clinical seizures prior to CEEG, initial EEG background category, and inter-ictal discharge category.

RESULTS

The model has fair to good discrimination ability and overall performance. At the optimal cut-off point in the validation dataset, the model has a sensitivity of 59% and a specificity of 81%. Varied cut-off points could be chosen to optimize sensitivity or specificity depending on available CEEG resources.

CONCLUSION

Despite inherent variability between centers, a model developed using multi-center CEEG data and few readily available variables could guide the use of limited CEEG resources when applied at a single center. Depending on CEEG resources, centers could choose lower cut-off points to maximize identification of all patients with seizures (but with more patients monitored) or higher cut-off points to reduce resource utilization by reducing monitoring of lower risk patients (but with failure to identify some patients with seizures).

Risk factors for EEG seizures in neonates treated with hypothermia: a multicenter cohort study

OBJECTIVE

To assess the risk factors for electrographic seizures among neonates treated with therapeutic hypothermia for hypoxic-ischemic encephalopathy (HIE).

METHODS

Three-center observational cohort study of 90 term neonates treated with hypothermia, monitored with continuous video-EEG (cEEG) within the first day of life (median age at onset of recording 9.5 hours, interquartile range 6.3-14.5), and continued for >24 hours (total recording 93.3 hours, interquartile range 80.1-112.8 among survivors). A pediatric electroencephalographer at each site reviewed cEEGs for electrographic seizures and initial EEG background category.

RESULTS

A total of 43 (48%) had electrographic seizures, including 9 (10%) with electrographic status epilepticus. Abnormal initial EEG background classification (excessively discontinuous, depressed and undifferentiated, burst suppression, or extremely low voltage), but not clinical variables (including pH <6.8, base excess ≤-20, or 10-minute Apgar ≤ 3), was strongly associated with seizures.

CONCLUSIONS

Electrographic seizures are common among neonates with HIE undergoing hypothermia and are difficult to predict based on clinical features. These results justify the recommendation for cEEG monitoring in neonates treated with hypothermia.

Electrographic seizures after convulsive status epilepticus in children and young adults: a retrospective multicenter study

OBJECTIVE

To describe the prevalence, characteristics, and predictors of electrographic seizures after convulsive status epilepticus (CSE).

STUDY DESIGN

This was a multicenter retrospective study in which we describe clinical and electroencephalographic (EEG) features of children (1 month to 21 years) with CSE who underwent continuous EEG monitoring.

RESULTS

Ninety-eight children (53 males) with CSE (median age of 5 years) underwent subsequent continuous EEG monitoring after CSE. Electrographic seizures (with or without clinical correlate) were identified in 32 subjects (33%). Eleven subjects (34.4%) had electrographic-only seizures, 17 subjects (53.1%) had electroclinical seizures, and 4 subjects (12.5%) had an unknown clinical correlate. Of the 32 subjects with electrographic seizures, 15 subjects (46.9%) had electrographic status epilepticus. Factors associated with the occurrence of electrographic seizures after CSE were a previous diagnosis of epilepsy (P = .029) and the presence of interictal epileptiform discharges (P < .0005). The median (p25-p75) duration of stay in the pediatric intensive care unit was longer for children with electrographic seizures than for children without electrographic seizures (9.5 [3-22.5] vs 2 [2-5] days, Wilcoxon test, Z = 3.916, P = .0001). Four children (4.1%) died before leaving the hospital, and we could not identify a relationship between death and the presence or absence of electrographic seizures.

CONCLUSIONS

After CSE, one-third of children who underwent EEG monitoring experienced electrographic seizures, and among these, one-third experienced entirely electrographic-only seizures. A previous diagnosis of epilepsy and the presence of interictal epileptiform discharges were risk factors for electrographic seizures.

Electrographic seizures and status epilepticus in critically ill children and neonates with encephalopathy

Electrographic seizures are seizures that are evident on EEG monitoring. They are common in critically ill children and neonates with acute encephalopathy. Most electrographic seizures have no associated clinical changes, and continuous EEG monitoring is necessary for identification. The effect of electrographic seizures on outcome is the focus of active investigation. Studies have shown that a high burden of electrographic seizures is associated with worsened clinical outcome after adjustment for cause and severity of brain injury, suggesting that a high burden of such seizures might independently contribute to secondary brain injury. Further research is needed to determine whether identification and management of electrographic seizures reduces secondary brain injury and improves outcome in critically ill children and neonates.

Electrographic status epilepticus and long-term outcome in critically ill children

OBJECTIVE

Electrographic seizures (ES) and electrographic status epilepticus (ESE) are common in children in the pediatric intensive care unit (PICU) with acute neurologic conditions. We aimed to determine whether ES or ESE was associated with worse long-term outcomes.

METHODS

Three hundred children with an acute neurologic condition and encephalopathy underwent clinically indicated EEG monitoring and were enrolled in a prospective observational study. We aimed to obtain follow-up data from 137 subjects who were neurodevelopmentally normal before PICU admission.

RESULTS

Follow-up data were collected for 60 of 137 subjects (44%) at a median of 2.7 years. Subjects with and without follow-up data were similar in clinical characteristics during the PICU admission. Among subjects with follow-up data, ES occurred in 12 subjects (20%) and ESE occurred in 14 subjects (23%). Multivariable analysis indicated that ESE was associated with an increased risk of unfavorable Glasgow Outcome Scale (Extended Pediatric Version) category (odds ratio 6.36, p = 0.01) and lower Pediatric Quality of Life Inventory scores (23 points lower, p = 0.001). Among subjects without prior epilepsy diagnoses ESE was associated with an increased risk of subsequently diagnosed epilepsy (odds ratio 13.3, p = 0.002). ES were not associated with worse outcomes.

CONCLUSIONS

Among children with acute neurologic disorders who were reported to be neurodevelopmentally normal before PICU admission, ESE but not ES was associated with an increased risk of unfavorable global outcome, lower health-related quality of life scores, and an increased risk of subsequently diagnosed epilepsy even after adjusting for neurologic disorder category, EEG background category, and age.

Gaps and opportunities in refractory status epilepticus research in children: a multi-center approach by the Pediatric Status Epilepticus Research Group (pSERG)

PURPOSE

Status epilepticus (SE) is a life-threatening condition that can be refractory to initial treatment. Randomized controlled studies to guide treatment choices, especially beyond first-line drugs, are not available. This report summarizes the evidence that guides the management of refractory convulsive SE (RCSE) in children, defines gaps in our clinical knowledge and describes the development and works of the 'pediatric Status Epilepticus Research Group' (pSERG).

METHODS

A literature review was performed to evaluate current gaps in the pediatric SE and RCSE literature. In person and online meetings helped to develop and expand the pSERG network.

RESULTS

The care of pediatric RCSE is largely based on extrapolations of limited evidence derived from adult literature and supplemented with case reports and case series in children. No comparative effectiveness trials have been performed in the pediatric population. Gaps in knowledge include risk factors for SE, biomarkers of SE and RCSE, second- and third-line treatment options, and long-term outcome.

CONCLUSION

The care of children with RCSE is based on limited evidence. In order to address these knowledge gaps, the multicenter pSERG was established to facilitate prospective collection, analysis, and sharing of de-identified data and biological specimens from children with RCSE. These data will allow identification of treatment strategies associated with better outcomes and delineate evidence-based interventions to improve the care of children with SE.

Electroencephalography monitoring in critically ill children: current practice and implications for future study design

PURPOSE

Survey data indicate that continuous electroencephalography (EEG) (CEEG) monitoring is used with increasing frequency to identify electrographic seizures in critically ill children, but studies of current CEEG practice have not been conducted. We aimed to describe the clinical utilization of CEEG in critically ill children at tertiary care hospitals with a particular focus on variables essential for designing feasible prospective multicenter studies evaluating the impact of electrographic seizures on outcome.

METHODS

Eleven North American centers retrospectively enrolled 550 consecutive critically ill children who underwent CEEG. We collected data regarding subject characteristics, CEEG indications, and CEEG findings.

KEY FINDINGS

CEEG indications were encephalopathy with possible seizures in 67% of subjects, event characterization in 38% of subjects, and management of refractory status epilepticus in 11% of subjects. CEEG was initiated outside routine work hours in 47% of subjects. CEEG duration was <12 h in 16%, 12-24 h in 34%, and >24 h in 48%. Substantial variability existed among sites in CEEG indications and neurologic diagnoses, yet within each acute neurologic diagnosis category a similar proportion of subjects at each site had electrographic seizures. Electrographic seizure characteristics including distribution and duration varied across sites and neurologic diagnoses.

SIGNIFICANCE

These data provide a systematic assessment of recent CEEG use in critically ill children and indicate variability in practice. The results suggest that multicenter studies are feasible if CEEG monitoring pathways can be standardized. However, the data also indicate that electrographic seizure variability must be considered when designing studies that address the impact of electrographic seizures on outcome.

Electrographic seizures in pediatric ICU patients: cohort study of risk factors and mortality

OBJECTIVES

We aimed to determine the incidence of electrographic seizures in children in the pediatric intensive care unit who underwent EEG monitoring, risk factors for electrographic seizures, and whether electrographic seizures were associated with increased odds of mortality.

METHODS

Eleven sites in North America retrospectively reviewed a total of 550 consecutive children in pediatric intensive care units who underwent EEG monitoring. We collected data on demographics, diagnoses, clinical seizures, mental status at EEG onset, EEG background, interictal epileptiform discharges, electrographic seizures, intensive care unit length of stay, and in-hospital mortality.

RESULTS

Electrographic seizures occurred in 162 of 550 subjects (30%), of which 61 subjects (38%) had electrographic status epilepticus. Electrographic seizures were exclusively subclinical in 59 of 162 subjects (36%). A multivariable logistic regression model showed that independent risk factors for electrographic seizures included younger age, clinical seizures prior to EEG monitoring, an abnormal initial EEG background, interictal epileptiform discharges, and a diagnosis of epilepsy. Subjects with electrographic status epilepticus had greater odds of in-hospital death, even after adjusting for EEG background and neurologic diagnosis category.

CONCLUSIONS

Electrographic seizures are common among children in the pediatric intensive care unit, particularly those with specific risk factors. Electrographic status epilepticus occurs in more than one-third of children with electrographic seizures and is associated with higher in-hospital mortality.

Pediatric intracerebral hemorrhage: acute symptomatic seizures and epilepsy

IMPORTANCE

Seizures are believed to be common presenting symptoms in neonates and children with spontaneous intracerebral hemorrhage (ICH). However, few data are available on the epidemiology of acute symptomatic seizures or the risk for later epilepsy.

OBJECTIVE

To define the incidence of and explore risk factors for seizures and epilepsy in children with spontaneous ICH. Our a priori hypotheses were that younger age at presentation, cortical involvement of ICH, acute symptomatic seizures after presentation, ICH due to vascular malformation, and elevated intracranial pressure requiring urgent intervention would predict remote symptomatic seizures and epilepsy.

DESIGN

Prospective cohort study conducted between March 1, 2007, and January 1, 2012.

SETTING

Three tertiary care pediatric hospitals.

PARTICIPANTS

Seventy-three pediatric subjects with spontaneous ICH including 20 perinatal (≥37 weeks' gestation to 28 days) and 53 childhood subjects (>28 days to <18 years at presentation).

MAIN OUTCOME MEASURES

Acute symptomatic seizures (clinically evident and electrographic-only seizures within 7 days), remote symptomatic seizures, and epilepsy.

RESULTS

Acute symptomatic seizures occurred in 35 subjects (48%). Acute symptomatic seizures as a presenting symptom of ICH occurred in 12 perinatal (60%) and 19 childhood (36%) subjects (P = .07). Acute symptomatic seizures after presentation occurred in 7 children. Electrographic-only seizures were present in 9 of 32 subjects (28%) with continuous electroencephalogram monitoring. One-year and 2-year remote symptomatic seizure-free survival rates were 82% (95% CI, 68-90) and 67% (95% CI, 46-82), respectively. One-year and 2-year epilepsy-free survival rates were 96% (95% CI, 83-99) and 87% (95% CI, 65-95), respectively. Elevated intracranial pressure requiring acute intervention was a risk factor for seizures after presentation (P = .01; Fisher exact test), remote symptomatic seizures, and epilepsy (P = .03, and P = .04, respectively; log-rank test).

CONCLUSIONS AND RELEVANCE

Presenting seizures are common in perinatal and childhood ICH. Continuous electroencephalography may detect electrographic seizures in some subjects. Single remote symptomatic seizures occur in many, and development of epilepsy is estimated to occur in 13% of patients at 2 years. Elevated intracranial pressure requiring acute intervention is a risk factor for acute seizures after presentation, remote symptomatic seizures, and epilepsy.

Treatment of electrographic seizures and status epilepticus in critically ill children: a single center experience

PURPOSE

Electrographic seizures (ES) and electrographic status epilepticus (ESE) are common in encephalopathic children in the pediatric intensive care unit (PICU) and associated with worse short-term outcome. Survey data indicate most physicians treat ES and ESE with antiepileptic drugs (AEDs), but few data are available regarding AED usage patterns. We aimed to describe AED usage for ES and ESE in critically ill children.

METHODS

We performed an observational study of patients who underwent continuous electroencephalographic (cEEG) monitoring in the PICU of a single quaternary care children's hospital. We collected data regarding age, clinical diagnoses, ES and ESE occurrence, and AEDs utilized.

RESULTS

200 subjects underwent cEEG. ES occurred in 21% (41/200) and ESE occurred in 22% (43/200). Of the 84 patients with ES or ESE, 80 received non-benzodiazepine AEDs including 48% (38 of 80) with ES and 52% (42 of 80) with ESE. The most commonly administered first AEDs were levetiracetam in 38% (30/80), phenobarbital in 31% (25/80), phenytoin-fosphenytoin in 28% (22/80), and valproate in 4% (3/80). Seizures terminated after administration of the first AED in 74% (28/38) with ES and 22% (9/41) with ESE.

CONCLUSIONS

Levetiracetam, phenobarbital, and phenytoin-fosphenytoin are commonly used to manage ES and ESE at our center. Over half of subjects received multiple AEDs.

Abstract TMP99: Pediatric Intracerebral Hemorrhage: Acute Symptomatic Seizures and Epilepsy

Background and Objectives: We aimed to define the incidence of acute symptomatic seizures and of remote symptomatic seizures and epilepsy after spontaneous pediatric intracerebral hemorrhage (ICH).

Methods: Pediatric patients with spontaneous ICH presenting between 2007 and 2012 at three tertiary care centers were prospectively identified. Acute symptomatic seizures were defined as seizures occurring from presentation to 7 days after ICH. Survival analysis was used to assess development of a first remote symptomatic seizure and epilepsy (2 or more unprovoked seizures >7 days after ICH). Log-rank tests were used to examine putative risk factors for development of remote symptomatic seizures and epilepsy.

Results: Seventy-three pediatric subjects with spontaneous ICH were identified, including 20 perinatal (≥37 weeks gestation to 28 days) and 53 childhood subjects (>28 days to <18 years). Acute symptomatic seizures occurred in 12 (60%) perinatal and 23 (43%) childhood subjects, p=.29, Fisher’s exact. Median age of childhood subjects with acute symptomatic seizures was younger than those without (2.2 versus 10.8 years, p=.006, rank-sum). Electrographic-only seizures occurred in 28% of 32 subjects who had continuous EEG monitoring. Follow-up was not different between perinatal and childhood subjects (median 371 versus 340 days), p=.68, rank-sum. One and two-year remote symptomatic seizure-free survival were 82% (95% CI 68-91%) and 67% (95% CI 46-82%). One and two-year epilepsy-free survival were 96% (95% CI 83-99%) and 87% (95% CI 65-95%). Elevated intracranial pressure (ICP) requiring urgent intervention was a risk factor for remote symptomatic seizures and epilepsy (p=.024 and p=.037, log-rank test).

Conclusions: Acute symptomatic seizures are common in both perinatal and childhood ICH. Continuous EEG monitoring may identify electrographic-only seizures in some subjects. By two-years after ICH it is estimated that about one-third of patients will have a single remote symptomatic seizures and that about 13% will develop epilepsy. Elevated ICP requiring intervention is a risk factor for remote symptomatic seizures and epilepsy.

Impact of continuous EEG monitoring on clinical management in critically ill children

BACKGROUND

Continuous EEG (cEEG) monitoring is being used with increasing frequency in critically ill patients, most often to detect non-convulsive seizures. While cEEG is non-invasive and feasible in the critical care setting, it is also expensive and labor intensive, and there has been little study of its impact on clinical care. We aimed to determine prospectively the impact of cEEG on clinical management in critically ill children.

METHODS

Critically ill children (non-neonates) with acute encephalopathy underwent cEEG. Study enrollment and data collection were prospective.

RESULTS

100 children were studied. EEG monitoring led to specific clinical management changes in 59 children. These included initiating or escalating anti-seizure medications in 43 due to seizure detection, demonstrating that a specific event (subtle movement or vital sign change) was not a seizure in 21, or obtaining urgent neuroimaging that led to a clinical change in 3. In the remaining 41 children, cEEG ruled out the presence of non-convulsive seizures but did not lead to a specific change in clinical management.

CONCLUSIONS

EEG monitoring led to changes in clinical management in the majority of patients, suggesting it may have an important role in management of critically ill children. Further study is needed to determine whether the management changes elicited by cEEG improve outcome.

Common data elements for pediatric traumatic brain injury: recommendations from the working group on demographics and clinical assessment

The Common Data Elements (CDEs) initiative is a National Institutes of Health (NIH) interagency effort to standardize naming, definitions, and data structure for clinical research variables. Comparisons of the results of clinical studies of neurological disorders have been hampered by variability in data coding, definitions, and procedures for sample collection. The CDE project objective is to enable comparison of future clinical trials results in major neurological disorders, including traumatic brain injury (TBI), stroke, multiple sclerosis, and epilepsy. As part of this effort, recommendations for CDEs for research on TBI were developed through a 2009 multi-agency initiative. Following the initial recommendations of the Working Group on Demographics and Clinical Assessment, a separate workgroup developed recommendations on the coding of clinical and demographic variables specific to pediatric TBI studies for subjects younger than 18 years. This article summarizes the selection of measures by the Pediatric TBI Demographics and Clinical Assessment Working Group. The variables are grouped into modules which are grouped into categories. For consistency with other CDE working groups, each variable was classified by priority (core, supplemental, and emerging). Templates were produced to summarize coding formats, guide selection of data points, and provide procedural recommendations. This proposed standardization, together with the products of the other pediatric TBI working groups in imaging, biomarkers, and outcome assessment, will facilitate multi-center studies, comparison of results across studies, and high-quality meta-analyses of individual patient data.

EEG monitoring during therapeutic hypothermia in neonates, children, and adults

Therapeutic hypothermia is being utilized as a neuroprotective strategy in neonates, children, and adults. The most common indications are hypoxic ischemic encephalopathy in neonates and post cardiac arrest in adults. Electroencephalographic monitoring use is increasing in critical care units, and is sometimes a component of therapeutic hypothermia clinical pathways. Monitoring may detect non-convulsive seizures or non-convulsive status epilepticus, and it may provide prognostic information. We review data regarding indications for therapeutic hypothermia and electroencephalographic monitoring in neonatal, pediatric, and adult critical care units, and discuss technical aspects related to such monitoring.

Seizures as a presenting symptom of acute arterial ischemic stroke in childhood

OBJECTIVES

To define the incidence of seizures as a presenting symptom of acute arterial ischemic stroke (AIS) in children and to determine whether younger age, infarct location, or AIS etiology were risk factors for seizure at AIS presentation.

STUDY DESIGN

Children aged 2 months to 18 years presenting with AIS between January 2005 and December 2008 were identified from a single center prospective pediatric stroke registry. Clinical data were abstracted, and a neuroradiologist reviewed imaging studies.

RESULTS

Among the 60 children who met our inclusion criteria, 13 experienced seizure at stroke presentation (22%). Median age was significantly younger in children who presented with seizures than in those who did not (1.1 years vs 10 years; P = .0009). Seizures were accompanied by hemiparesis in all patients. Three of 4 children with clinically overt seizures at presentation also had nonconvulsive seizures on continuous electroencephalography monitoring.

CONCLUSIONS

Twenty-two percent of children with acute AIS present with seizures. Seizures were always accompanied by focal neurologic deficits. Younger age was a risk factor for seizures at presentation. Seizure at presentation was not associated with infarct location or etiology. Nonconvulsive seizures may occur during the acute period.

Electrographic seizures during therapeutic hypothermia for neonatal hypoxic-ischemic encephalopathy

Electrographic seizures are common in neonates with hypoxic-ischemic encephalopathy, but detailed data are not available regarding seizure incidence during therapeutic hypothermia. The objective of this prospective study was to determine the incidence and timing of electrographic seizures in term neonates undergoing whole-body therapeutic hypothermia for hypoxic-ischemic encephalopathy as detected by conventional full-array electroencephalography for 72 hours of therapeutic hypothermia and 24 hours of normothermia. Clinical and electroencephalography data were collected from 26 consecutive neonates. Electroencephalograms were reviewed by 2 pediatric neurophysiologists. Electrographic seizures occurred in 17 of 26 (65%) patients. Seizures were entirely nonconvulsive in 8 of 17 (47%), status epilepticus occurred in 4 of 17 (23%), and seizure onset was in the first 48 hours in 13 of 17 (76%) patients. Electrographic seizures were common, were often nonconvulsive, and had onset over a broad range of times in the first days of life.

Short-term outcome prediction by electroencephalographic features in children treated with therapeutic hypothermia after cardiac arrest

BACKGROUND

Electroencephalographic (EEG) features may provide objective data regarding prognosis in children resuscitated from cardiac arrest (CA), but therapeutic hypothermia (TH) may impact its predictive value. We aimed to determine whether specific EEG features were predictive of short-term outcome in children treated with TH after CA, both during hypothermia and after return to normothermia.

METHODS

Thirty-five children managed with a standard clinical TH algorithm after CA were prospectively enrolled. EEG recordings were scored in a standardized manner and categorized. EEG category 1 consisted of continuous and reactive tracings. EEG category 2 consisted of continuous but unreactive tracings. EEG category 3 included those with any degree of discontinuity, burst suppression, or lack of cerebral activity. The primary outcome was unfavorable short-term outcome defined as Pediatric Cerebral Performance Category score of 4-6 (severe disability, vegetative, death) at hospital discharge. Univariate analyses of the association between EEG category and outcome was performed using logistic regression.

RESULTS

For tracings obtained during hypothermia, patients with EEGs in categories 2 or 3 were far more likely to have poor outcome than those in category 1 (OR 10.7, P = 0.023 and OR 35, P = 0.004, respectively). Similarly, for tracings obtained during normothermia, patients with EEGs in categories 2 or 3 were far more likely to have poor outcomes than those in category 1 (OR 27, P = 0.006 and OR 18, P = 0.02, respectively).

CONCLUSIONS

A simple EEG classification scheme has predictive value for short-term outcome in children undergoing TH after CA.

Levetiracetam for treatment of neonatal seizures

Neonatal seizures are often refractory to treatment with initial antiseizure medications. Consequently, clinicians turn to alternatives such as levetiracetam, despite the lack of published data regarding its safety, tolerability, or efficacy in the neonatal population. We report a retrospectively identified cohort of 23 neonates with electroencephalographically confirmed seizures who received levetiracetam. Levetiracetam was considered effective if administration was associated with a greater than 50% seizure reduction within 24 hours. Levetiracetam was initiated at a mean conceptional age of 41 weeks. The mean initial dose was 16 ± 6 mg/kg and the mean maximum dose was 45 ± 19 mg/kg/day. No respiratory or cardiovascular adverse effects were reported or detected. Levetiracetam was associated with a greater than 50% seizure reduction in 35% (8 of 23), including seizure termination in 7. Further study is warranted to determine optimal levetiracetam dosing in neonates and to compare efficacy with other antiseizure medications.

Nonconvulsive seizures are common in critically ill children

BACKGROUND

Retrospective studies have reported the occurrence of nonconvulsive seizures in critically ill children. We aimed to prospectively determine the incidence and risk factors of nonconvulsive seizures in critically ill children using predetermined EEG monitoring indications and EEG interpretation terminology.

METHODS

Critically ill children (non-neonates) with acute encephalopathy underwent continuous EEG monitoring if they met institutional clinical practice criteria. Study enrollment and data collection were prospective. Logistic regression analysis was utilized to identify risk factors for seizure occurrence.

RESULTS

One hundred children were evaluated. Electrographic seizures occurred in 46 and electrographic status epilepticus occurred in 19. Seizures were exclusively nonconvulsive in 32. The only clinical risk factor for seizure occurrence was younger age (p=0.03). Of patients with seizures, only 52% had seizures detected in the first hour of monitoring, while 87% were detected within 24 hours.

CONCLUSIONS

Seizures were common in critically ill children with acute encephalopathy. Most were nonconvulsive. Clinical features had little predictive value for seizure occurrence. Further study is needed to confirm these data in independent high-risk populations, to clarify which children are at highest risk for seizures so limited monitoring resources can be allocated optimally, and to determine whether seizure detection and management improves outcome.

Medical treatment of pediatric status epilepticus

Status epilepticus (SE) is a common pediatric neurologic emergency that refers to a prolonged seizure or recurrent seizures without a return to baseline mental status between seizures. Appropriate treatment strategies are necessary to prevent prolonged SE and its associated morbidity and mortality. This review discusses the importance of a rapid and organized management approach, reviews data related to commonly utilized medications including benzodiazepines, phenytoin, phenobarbital, valproate sodium, and levetiracetam, and then provides a sample SE management algorithm.

Electroencephalographic monitoring during hypothermia after pediatric cardiac arrest

BACKGROUND

Hypoxic ischemic brain injury secondary to pediatric cardiac arrest (CA) may result in acute symptomatic seizures. A high proportion of seizures may be nonconvulsive, so accurate diagnosis requires continuous EEG monitoring. We aimed to determine the safety and feasibility of long-term EEG monitoring, to describe electroencephalographic background and seizure characteristics, and to identify background features predictive of seizures in children undergoing therapeutic hypothermia (TH) after CA.

METHODS

Nineteen children underwent TH after CA. Continuous EEG monitoring was performed during hypothermia (24 hours), rewarming (12-24 hours), and then an additional 24 hours of normothermia. The tolerability of these prolonged studies and the EEG background classification and seizure characteristics were described in a standardized manner.

RESULTS

No complications of EEG monitoring were reported or observed. Electrographic seizures occurred in 47% (9/19), and 32% (6/19) developed status epilepticus. Seizures were nonconvulsive in 67% (6/9) and electrographically generalized in 78% (7/9). Seizures commenced during the late hypothermic or rewarming periods (8/9). Factors predictive of electrographic seizures were burst suppression or excessively discontinuous EEG background patterns, interictal epileptiform discharges, or an absence of the expected pharmacologically induced beta activity. Background features evolved over time. Patients with slowing and attenuation tended to improve, whereas those with burst suppression tended to worsen.

CONCLUSIONS

EEG monitoring in children undergoing therapeutic hypothermia after cardiac arrest is safe and feasible. Electrographic seizures and status epilepticus are common in this setting but are often not detectable by clinical observation alone. The EEG background often evolves over time, with milder abnormalities improving and more severe abnormalities worsening.

Cerebral sinus venous thrombosis complicated by cerebellar hemorrhage in a child with acute promyelocytic leukemia

A 12-year-old boy who presented with headache and papilledema was diagnosed with cerebral sinus venous thrombosis and promyelocytic leukemia. Cerebral sinus venous thrombosis is an uncommon manifestation of acute promyelocytic leukemia, and acute promyelocytic leukemia is an unusual etiology for cerebral sinus venous thrombosis. This case highlights the importance of a complete evaluation for risk factors in a child presenting with cerebral sinus venous thrombosis. Anticoagulation was initiated for treatment of cerebral sinus venous thrombosis, and new asymptomatic hemorrhage was identified in the cerebellum 1 day later. Anticoagulation was discontinued for 5 days and then reinitiated in the intensive care unit without hemorrhage expansion or other complications. We review the literature regarding anticoagulation in children with cerebral sinus venous thrombosis and issues specific to acute promyelocytic leukemia. This case suggests that in a controlled setting, anticoagulation may be safe in selected patients with cerebellar hemorrhage.

Treatment of refractory status epilepticus: literature review and a proposed protocol

Refractory status epilepticus describes continuing seizures despite adequate initial pharmacologic treatment. This situation is common in children, but few data are available to guide management. We review the literature related to the pharmacologic treatment and overall management of refractory status epilepticus, including midazolam, pentobarbital, phenobarbital, propofol, inhaled anesthetics, ketamine, valproic acid, topiramate, levetiracetam, pyridoxine, corticosteroids, the ketogenic diet, and electroconvulsive therapy. Based on the available data, we present a sample treatment algorithm that emphasizes the need for rapid therapeutic intervention, employs consecutive medications with different mechanisms of action, and attempts to minimize the risk of hypotension. The initial steps suggest using benzodiazepines and phenytoin. Second steps suggest using levetiracetam or valproic acid, which exert few hemodynamic adverse effects and have multiple mechanisms of action. Additional management strategies that could be employed in tertiary-care settings, such as coma induction guided by continuous electroencephalogram monitoring and surgical options, are also discussed.

Subcutaneous sumatriptan in an adolescent with acute posttraumatic headache

Acute posttraumatic headache is common and can evolve into chronic posttraumatic headache, which is associated with medication overuse and disability. However, there are few studies to guide treatment management of acute posttraumatic headache. We describe an adolescent with acute posttraumatic headache that did not respond to several initial medications but had rapid and sustained improvement in headache and associated migrainous features with subcutaneous sumatriptan.

Vein of galen aneurysmal malformation with deep venous communication and subarachnoid hemorrhage

A previously healthy 2-year-old boy presented with the acute onset of left middle cerebral artery syndrome. Evaluation revealed subarachnoid hemorrhage and a vein of Galen aneurysmal malformation with angiographic reflux into the deep venous system. Analysis of the angioarchitecture of the lesion demonstrated the basis of the hemorrhage to be reflux into cortical veins. The case supports and underscores the clinical relevance of recent reports indicating that the venous drainage of a vein of Galen aneurysmal malformation may communicate with the normal deep venous system. Such a communication implies that endovascular or surgical obliteration of the venous side of a vein of Galen aneurysmal malformation may impair normal venous drainage, potentially resulting in a venous infract or hemorrhage.

Neonatal seizure detection using multichannel display of envelope trend

We aimed to determine whether analysis of EEG envelope trend aids bedside detection of neonatal seizures. Five neonatal EEGs with multiple seizures were used to determine optimal trend parameters for seizure detection. Using these parameters, envelope trends were generated on eight additional EEGs, evaluated by experienced and inexperienced users, and compared to traditional EEG interpretation. Seizures were best detected using envelope trend of 2-6 Hz activity over 20-s epochs. Experienced and inexperienced users identified 88% and 55% of prolonged seizures, respectively, 40% and 6% of brief seizures, and 20% and 0% of slowly evolving seizures. All users identified less than two false positives per hour. Thus, an experienced envelope trend user accurately identified longer seizures but did not identify brief or slowly evolving seizures. Less experienced users were less accurate. Trending may be a useful tool for seizure detection in some neonates.

Hypodense middle cerebral artery with fat embolus

A 44-year-old man developed a right middle cerebral artery territory stroke due to a large fat embolism after an aortic valve repair. We briefly review the phenomenon of fat embolism and discuss the salient radiographic (CT) finding in this case--a "hypodense artery sign."

Medical causes of headache in children

Headache may be considered primary or secondary, and secondary headaches may be caused by intracranial disorders or medical/systemic disorders. In many cases, headache may be a presenting symptom of the medical disorder, and accurate diagnosis will lead to specific treatment. In other cases, the headache may be a known complication of the disorder, but the underlying disorder must be considered in management plans. Medical causes of headache are so diverse that uniform screening tests are not useful. History and examination must guide the differential diagnosis, and management plans must be individualized.

Nonconvulsive status epilepticus in a pediatric intensive care unit

We aimed to describe nonconvulsive status epilepticus in terms of patient age, etiology, initial presentation, and electroencephalogram and neuroimaging findings. Twenty children with nonconvulsive status epilepticus were identified by a retrospective review of children who underwent long-term electroencephalogram monitoring in a pediatric intensive care unit. Age ranged from 2 months to 18 years, and in 30% of patients, the age was <1 year. Nonconvulsive status epilepticus occurred most commonly in children with prior epilepsy (35%) or congenital heart disease (25%). Prior to nonconvulsive status epilepticus, most had experienced isolated seizures (55%) or convulsive status epilepticus (20%), but some had only preceding mental-status change (25%). The most common etiologies were exacerbation of epilepsy (35%) and ischemic stroke (25%). No children aged <1 year had preexisting epilepsy. Electroencephalograms confirmed nonconvulsive status epilepticus immediately in 65%. Nonconvulsive status epilepticus lasted up to 8 days, and neuroimaging was abnormal in 82% of patients. Nonconvulsive status epilepticus occurs in a heterogeneous group of children, results from acute symptomatic etiologies in children aged <1 year, most frequently follows isolated convulsions but can occur with only preceding mental status change, and is often prolonged. These findings suggest that a high level of suspicion for nonconvulsive status epilepticus must be maintained, and long-term electroencephalogram monitoring may be indicated in a large number of patients.

Status epilepticus secondary to hypertensive encephalopathy as the presenting manifestation of Guillain-Barré syndrome

Malignant hypertension due to autonomic dysfunction is a known complication of Guillain-Barré syndrome. We describe a child who presented with status epilepticus secondary to hypertensive encephalopathy who, in recovery, was found to be areflexic. Nerve conduction studies confirmed the clinical diagnosis of Guillain-Barré syndrome. She was treated with antihypertensive and antiseizure medications and intravenous immune globulin with complete resolution of her autonomic symptoms and improvement in her weakness. Guillain-Barré syndrome may result in hypertensive encephalopathy that can manifest as status epilepticus before the onset of motor symptoms.

Lupus anticoagulant and thrombosis following Henoch-Schonlein purpura

A male adolescent developed a sinovenous thrombosis 4 weeks following a Henoch-Schonlein purpura episode. A hypercoagulation evaluation revealed a positive lupus anticoagulant. This suggests an association between Henoch-Schonlein purpura and antiphospholipid antibody syndrome and is the first report of sinovenous thrombosis after Henoch-Schonlein purpura that was likely due to elevated antiphospholipids. Children who develop Henoch-Schonlein purpura with neurologic features including headache should be evaluated for sinovenous thrombosis and a hypercoagulable state.

Tactile attention tasks enhance activation in somatosensory regions of parietal cortex: a positron emission tomography study

We used positron emission tomography to study cortical regions mediating tactile attention. Cues selectively directed subjects to attend to the roughness or duration of contact with embossed gratings that rubbed against a single fingertip with controlled speed and force. The task required discriminating between paired gratings that differed in tactile features of roughness and/or length. For different blocks of trials, cues directed attention to one tactile feature or indicated a divided attention strategy to a change in either feature. All attention conditions unambiguously activated several somatosensory foci in the parietal cortex, including somatotopically appropriate portions of the primary somatosensory cortex in the postcentral gyrus (S1) and the secondary somatosensory region (S2) within parietal opercular regions. There was no evidence for separate processing foci for selective and divided attention strategies, or for selectively attending to roughness versus stimulus duration. We observed a greater magnitude blood flow change in S2 versus S1 during attention tasks, which suggests that S2 might actually influence S1 activity. Despite these differences, modulation of S1 and S2 supports concepts of early selection in tactile attention. There were also examples of non-sensory foci in frontal cortex, anterior cingulate gyrus and bilateral superior parietal regions at the fundus of the postcentral sulcus. Posterior parietal regions observed in this study did not overlap foci seen in studies of visual attention. Thus, the posterior parietal region may be subdivided into modality-specific subregions, each of which processes information needed to attend to a specific modality. These non-sensory areas may constitute a network that provides a source of modulating influences on the earlier stage, sensory areas.