Unrecognized Focal Nonmotor Seizures in Adolescents Presenting to Emergency Departments

BACKGROUND AND OBJECTIVES

Many adolescents with undiagnosed focal epilepsy seek evaluation in emergency departments (EDs). Accurate history-taking is essential to prompt diagnosis and treatment. In this study, we investigated ED recognition of motor vs nonmotor seizures and its effect on management and treatment of focal epilepsy in adolescents.

METHODS

This was a retrospective analysis of enrollment data from the Human Epilepsy Project (HEP), an international multi-institutional study that collected data from 34 sites between 2012 and 2017. Participants were 12 years or older, neurotypical, and within 4 months of treatment initiation for focal epilepsy. We used HEP enrollment medical records to review participants' initial diagnosis and management.

RESULTS

A total of 83 adolescents were enrolled between 12 and 18 years. Fifty-eight (70%) presented to an ED before diagnosis of epilepsy. Although most ED presentations were for motor seizures (n = 52; 90%), many patients had a history of nonmotor seizures (20/52 or 38%). Adolescents with initial nonmotor seizures were less likely to present to EDs (26/44 or 59% vs 32/39 or 82%, p = 0.02), and nonmotor seizures were less likely to be correctly identified (2/6 or 33% vs 42/52 or 81%, p = 0.008). A history of initial nonmotor seizures was not recognized in any adolescent who presented for a first-lifetime motor seizure. As a result, initiation of treatment and admission from the ED was not more likely for these adolescents who met the definition of epilepsy compared with those with no seizure history. This lack of nonmotor seizure history recognition in the ED was greater than that observed in the adult group (0% vs 23%, p = 0.03) and occurred in both pediatric and nonpediatric ED settings.

DISCUSSION

Our study supports growing evidence that nonmotor seizures are often undiagnosed, with many individuals coming to attention only after conversion to motor seizures. We found this treatment gap is exacerbated in the adolescent population. Our study highlights a critical need for physicians to inquire about the symptoms of nonmotor seizures, even when the presenting seizure is motor. Future interventions should focus on improving nonmotor seizure recognition for this population in EDs.

GWAS meta-analysis of over 29,000 people with epilepsy identifies 26 risk loci and subtype-specific genetic architecture

Epilepsy is a highly heritable disorder affecting over 50 million people worldwide, of which about one-third are resistant to current treatments. Here we report a multi-ancestry genome-wide association study including 29,944 cases, stratified into three broad categories and seven subtypes of epilepsy, and 52,538 controls. We identify 26 genome-wide significant loci, 19 of which are specific to genetic generalized epilepsy (GGE). We implicate 29 likely causal genes underlying these 26 loci. SNP-based heritability analyses show that common variants explain between 39.6% and 90% of genetic risk for GGE and its subtypes. Subtype analysis revealed markedly different genetic architectures between focal and generalized epilepsies. Gene-set analyses of GGE signals implicate synaptic processes in both excitatory and inhibitory neurons in the brain. Prioritized candidate genes overlap with monogenic epilepsy genes and with targets of current antiseizure medications. Finally, we leverage our results to identify alternate drugs with predicted efficacy if repurposed for epilepsy treatment.

Antiseizure Medication Withdrawal in Seizure-Free Patients: Practice Advisory Update Summary: Report of the AAN Guideline Subcommittee

OBJECTIVE

To update a 1996 American Academy of Neurology practice parameter.

METHODS

The authors systematically reviewed literature published from January 1991 to March 2020.

RESULTS

The long-term (24-60 months) risk of seizure recurrence is possibly higher among adults who have been seizure-free for 2 years and taper antiseizure medications (ASMs) vs those who do not taper ASMs (15% vs 7% per the 1 Class I article addressing this issue). In pediatric patients, there is probably no significant difference in seizure recurrence between those who begin tapering ASMs after 2 years vs 4 years of seizure freedom, and there is insufficient evidence of significant difference in risk of seizure recurrence between those who taper ASMs after 18 months of seizure freedom and those tapering after 24 months. There is insufficient evidence that the rate of seizure recurrence with ASM withdrawal following epilepsy surgery after 1 year of seizure freedom vs after 4 years is not significantly different than maintaining patients on ASMs. An epileptiform EEG in pediatric patients increases the risk of seizure recurrence. ASM withdrawal possibly does not increase the risk of status epilepticus in adults. In seizure-free adults, ASM weaning possibly does not change quality of life. Withdrawal of ASMs at 25% every 10 days to 2 weeks is probably not significantly different from withdrawal at 25% every 2 months in children who are seizure-free in more than 4 years of follow-up.

RECOMMENDATIONS

Fourteen recommendations were developed.

Adjunctive everolimus therapy for tuberous sclerosis complex-associated refractory seizures: Results from the postextension phase of EXIST-3

OBJECTIVE

Epilepsy is highly prevalent in patients with tuberous sclerosis complex (TSC). Everolimus showed higher efficacy than placebo for seizures in the primary analysis of the EXIST-3 study. Here, we present the long-term outcomes of everolimus at the end of the postextension phase (PEP; data cutoff date: October 25, 2017).

METHODS

After completion of the extension phase, patients were invited to continue everolimus in the PEP with everolimus (targeted trough concentration = 5-15 ng/ml, investigator-judged). Efficacy assessments included changes in seizure status during the PEP collected at 12-week intervals as parent/caregiver-reported data through a structured questionnaire.

RESULTS

Among 361 patients, 343 entered the extension phase and 249 entered the PEP. After 12 weeks in the PEP, 18.9% (46/244) of patients were seizure-free since the last visit of the extension phase and 64.8% (158/244) had a stable/improved seizure status. At 24 weeks, the corresponding percentages were 18.2% (42/231) and 64.5% (149/231). Among 244 patients, the response rate was 32.8% (80/244) during the 12-week maintenance period of the core phase and 63.9% (156/244) at the end of the extension phase. Of the 149 responders at the end of the extension phase, 70.5% were seizure-free or had stable/improved seizure status. Long-term efficacy data showed persistent responses were observed in 183 of 361 patients (50.7%); 63.9% of these patients had a response that lasted at least 48 weeks. The most frequent Grade 3-4 adverse events (≥2% incidence) reported throughout the study were pneumonia, status epilepticus, seizure, stomatitis, neutropenia, and gastroenteritis. Four patients died during the study.

SIGNIFICANCE

The final analysis of EXIST-3 demonstrated the sustained efficacy of everolimus as adjunctive therapy in patients with TSC-associated treatment-refractory seizures, with a tolerable safety profile.

Capturing seizures in clinical trials of antiseizure medications for KCNQ2-DEE

Literature review of patients with KCNQ2 developmental and epileptic encephalopathy (KCNQ2-DEE) reveals, based on 16 reports including 139 patients, a clinical phenotype that includes age- and disease-specific stereotyped seizures. The typical seizure type of KCNQ2-DEE, focal tonic, starts within 0-5 days of life and is readily captured by video-electroencephalography VEEG for clinical and genetic diagnosis. After initial identification, KCNQ2-DEE seizures are clinically apparent and can be clearly identified without the use of EEG or VEEG. Therefore, we propose that the 2019 recommendations from the International League against Epilepsy (ILAE), the Pediatric Epilepsy Research Consortium (PERC), for capturing and recording seizures for clinical trials (Epilepsia Open, 4, 2019, 537) are suitable for use in KCNQ2-DEE‒associated antiseizure medicine (ASM) treatment trials. The ILAE/PERC consensus guidance states that a caregiver-maintained seizure diary, completed by caregivers who are trained to recognize seizures using within-patient historical recordings, accurately captures seizures prospectively in a clinical trial. An alternative approach historically endorsed by the Food and Drug Administration (FDA) compares seizure counts captured on VEEG before and after treatment. A major advantage of the ILAE/PERC strategy is that it expands the numbers of eligible patients who meet inclusion criteria of clinical trials while maintaining accurate seizure counts (Epilepsia Open, 4, 2019, 537). Three recent phase 3 pivotal pediatric trials investigating ASMs to treat syndromic seizures in patients as young as 2 years of age (N Engl J Med, 17, 2017, 699; Lancet, 21, 2020, 2243; Lancet, 17, 2018, 1085); and ongoing phase 2 open-label pediatric clinical trial that includes pediatric epileptic syndromes as young as 1 month of age (Am J Med Genet A, 176, 2018, 773), have already used caregiver-maintained seizure diaries successfully. For determining the outcome of a KCNQ2-DEE ASM treatment trial, the use of a seizure diary to count seizures by trained observers is feasible because the seizures of KCNQ2-DEE are clinically apparent. This strategy is supported by successful precedent in clinical trials in similar age groups and has the endorsement of the international pediatric epilepsy community.

Management of Infantile Spasms During the COVID-19 Pandemic

Circumstances of the COVID-19 pandemic have mandated a change to standard management of infantile spasms. On April 6, 2020, the Child Neurology Society issued an online statement of immediate recommendations to streamline diagnosis and treatment of infantile spasms with utilization of telemedicine, outpatient studies, and selection of first-line oral therapies as initial treatment. The rationale for the recommendations and specific guidance including follow-up assessment are provided in this manuscript. These recommendations are indicated as enduring if intended to outlast the pandemic, and limited if intended only for the pandemic health care crisis but may be applicable to future disruptions of health care delivery.

Ultra-Rare Genetic Variation in the Epilepsies: A Whole-Exome Sequencing Study of 17,606 Individuals

Sequencing-based studies have identified novel risk genes associated with severe epilepsies and revealed an excess of rare deleterious variation in less-severe forms of epilepsy. To identify the shared and distinct ultra-rare genetic risk factors for different types of epilepsies, we performed a whole-exome sequencing (WES) analysis of 9,170 epilepsy-affected individuals and 8,436 controls of European ancestry. We focused on three phenotypic groups: severe developmental and epileptic encephalopathies (DEEs), genetic generalized epilepsy (GGE), and non-acquired focal epilepsy (NAFE). We observed that compared to controls, individuals with any type of epilepsy carried an excess of ultra-rare, deleterious variants in constrained genes and in genes previously associated with epilepsy; we saw the strongest enrichment in individuals with DEEs and the least strong in individuals with NAFE. Moreover, we found that inhibitory GABA_A receptor genes were enriched for missense variants across all three classes of epilepsy, whereas no enrichment was seen in excitatory receptor genes. The larger gene groups for the GABAergic pathway or cation channels also showed a significant mutational burden in DEEs and GGE. Although no single gene surpassed exome-wide significance among individuals with GGE or NAFE, highly constrained genes and genes encoding ion channels were among the lead associations; such genes included CACNA1G, EEF1A2, and GABRG2 for GGE and LGI1, TRIM3, and GABRG2 for NAFE. Our study, the largest epilepsy WES study to date, confirms a convergence in the genetics of severe and less-severe epilepsies associated with ultra-rare coding variation, and it highlights a ubiquitous role for GABAergic inhibition in epilepsy etiology.

Infantile Spasms of Unknown Cause: Predictors of Outcome and Genotype-Phenotype Correlation

BACKGROUND

No large-scale studies have specifically evaluated the outcomes of infantile spasms (IS) of unknown cause, previously known as cryptogenic or idiopathic. The Epilepsy Phenome/Genome Project aimed to characterize IS of unknown cause by phenotype and genotype analysis.

METHODS

We undertook a retrospective multicenter observational cohort of 133 individuals within the Epilepsy Phenome/Genome Project database met criteria for IS of unknown cause with at least six months of follow-up data. Clinical medical records, imaging, and electroencephalography were examined.

RESULTS

Normal development occurred in only 15% of IS of unknown cause. The majority (85%) had clinically documented developmental delay (15% mild, 20% moderate, and 50% severe) at last assessment (median 2.7 years; interquartile interval 1.71-6.25 years). Predictors of positive developmental outcomes included no delay prior to IS (P < 0.001), older age of IS onset (median six months old), and resolution of IS after initial treatment (P < 0.001). Additional seizures after IS occurred in 67%, with predictors being seizures prior to IS (P = 0.018), earlier age of IS onset (median five months old), and refractory IS (P = 0.008). On a research basis, whole exome sequencing identified 15% with de novo variants in known epilepsy genes. Individuals with a genetic finding were more likely to have poor developmental outcomes (P = 0.035).

CONCLUSIONS

The current study highlights the predominately unfavorable developmental outcomes and that subsequent seizures are common in children with IS of unknown cause. Ongoing genetic evaluation of IS of seemingly unknown cause is likely to yield a diagnosis and provide valuable prognostic information.

Everolimus for treatment-refractory seizures in TSC: Extension of a randomized controlled trial

Background

EXamining everolimus In a Study of Tuberous sclerosis 3 (EXIST-3) demonstrated significantly reduced seizure frequency (SF) with everolimus vs placebo. In this study, we evaluate the long-term efficacy and safety of everolimus for tuberous sclerosis complex (TSC)-associated treatment-refractory seizures.

Methods

After completion of the core phase, patients could enter an open-label extension phase and receive everolimus (target exposure, 3-15 ng/mL) for ≥48 weeks. Efficacy end points included change from baseline in average weekly SF expressed as response rate (RR, ≥50% reduction) and median percentage reduction (PR).

Results

Of 366 patients, 361 received everolimus in core/extension phases. The RR was 31% (95% CI, 26.2-36.1; N = 352) at week 18, 46.6% (95% CI, 40.9-52.5; N = 298) at 1 year, and 57.7% (95% CI, 49.7-65.4; N = 163) at 2 years. Median PR in SF was 31.7% (95% CI, 28.5-36.1) at week 18, 46.7% (95% CI, 40.2-54) at 1 year, and 56.9% (95% CI, 50-68.4) at 2 years. Ninety-five patients (26.3%) discontinued everolimus before 2 years; 103 (28.5%) had <2 years of follow-up at study cutoff, and 40% were exposed to everolimus for ≥2 years. An analysis classifying discontinued patients as nonresponders showed an RR of 30.2% (95% CI, 25.5-35.2; N = 361) at week 18, 38.8% (95% CI, 33.7-44.1; N = 358) at 1 year, and 41% (95% CI, 34.6-47.7; N = 229) at 2 years, suggesting sustained benefit over time. The incidence of grade 3/4 adverse events (AEs) (any cause) was 40.2%, and 13% discontinued because of AEs (pneumonia [1.7%] and stomatitis [1.4%]). Two deaths were suspected to be treatment-related (pneumonia and septic shock).

Conclusions

Sustained reductions in TSC-associated treatment-refractory seizures over time were achieved with adjunctive everolimus. The safety profile was consistent with the core phase with no new safety concerns.

Classification of evidence

This study provides Class IV evidence that long-term everolimus therapy reduces SF in patients with TSC-associated treatment-refractory seizures.

Spike persistence and normalization in benign epilepsy with centrotemporal spikes - Implications for management

PURPOSE

This study was performed 1) to determine the timing of spike normalization in patients with benign epilepsy with centrotemporal spikes (BECTS); 2) to identify relationships between age of seizure onset, age of spike normalization, years of spike persistence and treatment; and 3) to assess final outcomes between groups of patients with or without spikes at the time of medication tapering.

METHODS

Retrospective analysis of BECTS patients confirmed by clinical data, including age of onset, seizure semiology and serial electroencephalography (EEG) from diagnosis to remission. Age at spike normalization, years of spike persistence, and time of treatment onset to spike normalization were assessed. Final seizure and EEG outcome were compared between the groups with or without spikes at the time of AED tapering.

RESULTS

One hundred and thirty-four patients were included. Mean age at seizure onset was 7.52 ± 2.11 years. Mean age at spike normalization was 11.89 ± 2.11 (range: 6.3-16.8) years. Mean time of treatment onset to spike normalization was 4.11 ± 2.13 (range: 0.24-10.08) years. Younger age of seizure onset was correlated with longer duration of spike persistence (r = -0.41, p < 0.001). In treated patients, spikes persisted for 4.1 ± 1.95 years, compared with 2.9 ± 1.97 years in untreated patients. No patients had recurrent seizures after AED was discontinued, regardless of the presence/absence of spikes at time of AED tapering.

CONCLUSION

Years of spike persistence was longer in early onset BECTS patients. Treatment with AEDs did not shorten years of spike persistence. Persistence of spikes at time of treatment withdrawal was not associated with seizure recurrence.

Detection of generalized tonic-clonic seizures using surface electromyographic monitoring

Objective

A prospective multicenter phase III trial was undertaken to evaluate the performance and tolerability in the epilepsy monitoring unit (EMU) of an investigational wearable surface electromyographic (sEMG) monitoring system for the detection of generalized tonic–clonic seizures (GTCSs).

Methods

One hundred ninety‐nine patients with a history of GTCSs who were admitted to the EMU in 11 level IV epilepsy centers for clinically indicated video‐electroencephalographic monitoring also received sEMG monitoring with a wearable device that was worn on the arm over the biceps muscle. All recorded sEMG data were processed at a central site using a previously developed detection algorithm. Detected GTCSs were compared to events verified by a majority of three expert reviewers.

Results

For all subjects, the detection algorithm detected 35 of 46 (76%, 95% confidence interval [CI] = 0.61–0.87) of the GTCSs, with a positive predictive value (PPV) of 0.03 and a mean false alarm rate (FAR) of 2.52 per 24 h. For data recorded while the device was placed over the midline of the biceps muscle, the system detected 29 of 29 GTCSs (100%, 95% CI = 0.88–1.00), with a detection delay averaging 7.70 s, a PPV of 6.2%, and a mean FAR of 1.44 per 24 h. Mild to moderate adverse events were reported in 28% (55 of 199) of subjects and led to study withdrawal in 9% (17 of 199). These adverse events consisted mostly of skin irritation caused by the electrode patch that resolved without treatment. No serious adverse events were reported.

Significance

Detection of GTCSs using an sEMG monitoring device on the biceps is feasible. Proper positioning of this device is important for accuracy, and for some patients, minimizing the number of false positives may be challenging.

DNM1 encephalopathy: A new disease of vesicle fission

OBJECTIVE

To evaluate the phenotypic spectrum caused by mutations in dynamin 1 (DNM1), encoding the presynaptic protein DNM1, and to investigate possible genotype-phenotype correlations and predicted functional consequences based on structural modeling.

METHODS

We reviewed phenotypic data of 21 patients (7 previously published) with DNM1 mutations. We compared mutation data to known functional data and undertook biomolecular modeling to assess the effect of the mutations on protein function.

RESULTS

We identified 19 patients with de novo mutations in DNM1 and a sibling pair who had an inherited mutation from a mosaic parent. Seven patients (33.3%) carried the recurrent p.Arg237Trp mutation. A common phenotype emerged that included severe to profound intellectual disability and muscular hypotonia in all patients and an epilepsy characterized by infantile spasms in 16 of 21 patients, frequently evolving into Lennox-Gastaut syndrome. Two patients had profound global developmental delay without seizures. In addition, we describe a single patient with normal development before the onset of a catastrophic epilepsy, consistent with febrile infection-related epilepsy syndrome at 4 years. All mutations cluster within the GTPase or middle domains, and structural modeling and existing functional data suggest a dominant-negative effect on DMN1 function.

CONCLUSIONS

The phenotypic spectrum of DNM1-related encephalopathy is relatively homogeneous, in contrast to many other genetic epilepsies. Up to one-third of patients carry the recurrent p.Arg237Trp variant, which is now one of the most common recurrent variants in epileptic encephalopathies identified to date. Given the predicted dominant-negative mechanism of this mutation, this variant presents a prime target for therapeutic intervention.

Adjunctive everolimus therapy for treatment-resistant focal-onset seizures associated with tuberous sclerosis (EXIST-3): a phase 3, randomised, double-blind, placebo-controlled study

BACKGROUND

Everolimus, a mammalian target of rapamycin (mTOR) inhibitor, has been used for various benign tumours associated with tuberous sclerosis complex. We assessed the efficacy and safety of two trough exposure concentrations of everolimus, 3-7 ng/mL (low exposure) and 9-15 ng/mL (high exposure), compared with placebo as adjunctive therapy for treatment-resistant focal-onset seizures in tuberous sclerosis complex.

METHODS

In this phase 3, randomised, double-blind, placebo-controlled study, eligible patients aged 2-65 years with tuberous sclerosis complex and treatment-resistant seizures (≥16 in an 8-week baseline phase) receiving one to three concomitant antiepileptic drugs were recruited from 99 centres across 25 countries. Participants were randomly assigned (1:1:1), via permuted-block randomisation (block size of six) implemented by Interactive Response Technology software, to receive placebo, low-exposure everolimus, or high-exposure everolimus. Randomisation was stratified by age subgroup (<6 years, 6 to <12 years, 12 to <18 years, and ≥18 years). Patients, investigators, site personnel, and the sponsor's study team were masked to treatment allocation. The starting dose of everolimus depended on age, body-surface area, and concomitant use of cytochrome 3A4/P-glycoprotein inducers. Dose adjustments were done to attain target trough ranges during a 6-week titration period, and as needed during a 12-week maintenance period of core phase. Patients or their caregivers recorded events in a seizure diary throughout the study. The primary endpoint was change from baseline in the frequency of seizures during the maintenance period, defined as response rate (the proportion of patients achieving ≥50% reduction in seizure frequency) and median percentage reduction in seizure frequency, in all randomised patients. This study is registered with ClinicalTrials.gov, number NCT01713946.

FINDINGS

Between July 3, 2013, and May 29, 2015, 366 patients were enrolled and randomly assigned to placebo (n=119), low-exposure everolimus, (n=117), or high-exposure everolimus (n=130). The response rate was 15·1% with placebo (95% CI 9·2-22·8; 18 patients) compared with 28·2% for low-exposure everolimus (95% CI 20·3-37·3; 33 patients; p=0·0077) and 40·0% for high-exposure everolimus (95% CI 31·5-49·0; 52 patients; p<0·0001). The median percentage reduction in seizure frequency was 14·9% (95% CI 0·1-21·7) with placebo versus 29·3% with low-exposure everolimus (95% CI 18·8-41·9; p=0·0028) and 39·6% with high-exposure everolimus (95% CI 35·0-48·7; p<0·0001). Grade 3 or 4 adverse events occurred in 13 (11%) patients in the placebo group, 21 (18%) in the low-exposure group, and 31 (24%) in the high-exposure group. Serious adverse events were reported in three (3%) patients who received placebo, 16 (14%) who received low-exposure everolimus, and 18 (14%) who received high-exposure everolimus. Adverse events led to treatment discontinuation in two (2%) patients in the placebo group versus six (5%) in the low-exposure group and four (3%) in the high-exposure group.

INTERPRETATION

Adjunctive everolimus treatment significantly reduced seizure frequency with a tolerable safety profile compared with placebo in patients with tuberous sclerosis complex and treatment-resistant seizures.

FUNDING

Novartis Pharmaceuticals Corporation.

Delineating the GRIN1 phenotypic spectrum: A distinct genetic NMDA receptor encephalopathy

Objective:

To determine the phenotypic spectrum caused by mutations in GRIN1 encoding the NMDA receptor subunit GluN1 and to investigate their underlying functional pathophysiology.

Methods:

We collected molecular and clinical data from several diagnostic and research cohorts. Functional consequences of GRIN1 mutations were investigated in Xenopus laevis oocytes.

Results:

We identified heterozygous de novo GRIN1 mutations in 14 individuals and reviewed the phenotypes of all 9 previously reported patients. These 23 individuals presented with a distinct phenotype of profound developmental delay, severe intellectual disability with absent speech, muscular hypotonia, hyperkinetic movement disorder, oculogyric crises, cortical blindness, generalized cerebral atrophy, and epilepsy. Mutations cluster within transmembrane segments and result in loss of channel function of varying severity with a dominant-negative effect. In addition, we describe 2 homozygous GRIN1 mutations (1 missense, 1 truncation), each segregating with severe neurodevelopmental phenotypes in consanguineous families.

Conclusions:

De novo GRIN1 mutations are associated with severe intellectual disability with cortical visual impairment as well as oculomotor and movement disorders being discriminating phenotypic features. Loss of NMDA receptor function appears to be the underlying disease mechanism. The identification of both heterozygous and homozygous mutations blurs the borders of dominant and recessive inheritance of GRIN1-associated disorders.

Impact of an ICU EEG monitoring pathway on timeliness of therapeutic intervention and electrographic seizure termination

OBJECTIVES

We aimed to determine whether implementation of a structured multidisciplinary electroencephalography (EEG) monitoring pathway improved the timeliness of administration of antiseizure medication in response to electrographic seizures in encephalopathic critically ill children.

METHODS

A multidisciplinary team developed a pathway to standardize EEG monitoring and seizure management in encephalopathic critically ill children, aiming to decrease the time from electrographic seizure onset to antiseizure medication administration. Data were collected to inform the team of improvement opportunities, which were then provided by an institutional pathway, staff education, and streamlined communication. Measurements were obtained before and after pathway implementation to assess for improvement.

RESULTS

We collected data on 41 patients before and 21 after pathway implementation. There were no differences between the baseline and pathway groups in demographic characteristics, acute encephalopathy etiologies, or antiseizure medications utilized. The median duration [interquartile range, IQR] from seizure onset to antiseizure medication administration was shorter for patients treated with the pathway (64 min [50, 101]) compared to patients treated prior to pathway implementation (139 min [71, 189]; p = 0.0006). The median [IQR] interval from seizure onset to antiseizure medication order was shorter for the pathway group (31 min [20, 49]) than the baseline group (71 min [33, 131]; p = 0.003). The median [IQR] interval from antiseizure medication order to administration was shorter for the pathway group (30 min [19, 40]) than the baseline group (40 min [17, 68]) (p = 0.047). Seizure termination was more likely to occur following initial antiseizure medication administration in the pathway than baseline group (67% vs. 27%, p = 0.002).

SIGNIFICANCE

Implementation of the pathway resulted in a significant reduction in the duration between electrographic seizure onset and antiseizure medication administration, and a significant increase in the rate of electrographic seizure termination following an initial antiseizure medication. Further study is needed to determine whether these changes are associated with improved outcomes.

The nature of neonatal status epilepticus--a clinician's perspective

Neonatal status epilepticus occurs within the substrate of the hyperexcitable newborn brain and is usually provoked by acute CNS derangements, although status can also be the presentation of early-life epilepsy. Provoked neonatal status usually resolves within a few days, with or without treatment, but new data suggests that status is associated with adverse outcomes, even after controlling for underlying disease severity and MRI structural brain injury. Novel treatments may be needed to improve seizure control and outcome, given the characteristics of neurotransmission in the newborn brain. This article is part of a Special Issue entitled "Status Epilepticus".

Electrographic status epilepticus and neurobehavioral outcomes in critically ill children

PURPOSE

Electrographic seizures (ESs) and electrographic status epilepticus (ESE) are common in children with acute neurologic conditions in pediatric intensive care units (PICUs), and ESE is associated with worse functional and quality-of-life outcomes. As an exploratory study, we aimed to determine if ESE was associated with worse outcomes using more detailed neurobehavioral measures.

METHODS

Three hundred children with an acute neurologic condition and altered mental status underwent clinically indicated EEG monitoring and were enrolled in a prospective observational study. We obtained follow-up data from subjects who were neurodevelopmentally normal prior to PICU admission. We evaluated for associations between ESE and adaptive behavior (Adaptive Behavior Assessment System-II, ABAS-II), behavioral and emotional problems (Child Behavior Checklist, CBCL), and executive function (Behavior Rating Inventory of Executive Function, BRIEF) using linear regression analyses. A p-value of <0.05 was considered significant.

RESULTS

One hundred thirty-seven of 300 subjects were neurodevelopmentally normal prior to PICU admission. We obtained follow-up data from 36 subjects for the CBCL, 32 subjects for the ABAS-II, and 20 subjects for the BRIEF. The median duration from admission to follow-up was 2.6 years (IQR: 1.2-3.8). There were no differences in the acute care variables (age, sex, mental status category, intubation status, paralysis status, acute neurologic diagnosis category, seizure category, EEG background category, or short-term outcome) between subjects with and without follow-up data for any of the outcome measures. On univariate analysis, significant differences were not identified for CBCL total problem (ES coefficient: -4.1, p = 0.48; ESE coefficient: 8.9, p = 0.13) or BRIEF global executive function (ES coefficient: 2.1, p = 0.78; ESE coefficient: 14.1, p = 0.06) scores, although there were trends toward worse scores in subjects with ESE. On univariate analysis, ESs were not associated with worse scores (coefficient: -21.5, p = 0.051), while ESE (coefficient: -29.7, p = 0.013) was associated with worse ABAS-II adaptive behavioral global composite scores. On multivariate analysis, when compared to subjects with no seizures, both ESs (coefficient: -28, p=0.014) and ESE (coefficient: -36, p = 0.003) were associated with worse adaptive behavioral global composite scores.

DISCUSSION

Among previously neurodevelopmentally normal children with acute neurologic disorders, ESs and ESE were associated with worse adaptive behavior and trends toward worse behavioral-emotional and executive function problems. This was a small exploratory study, and the impact of ESs and ESE on these neurobehavioral measures may be clarified by subsequent larger studies. This article is part of a Special Issue entitled "Status Epilepticus".

Retention rates of rufinamide in pediatric epilepsy patients with and without Lennox-Gastaut Syndrome

OBJECTIVE

To evaluate the effectiveness of rufinamide (RFM) in patients with Lennox-Gastaut Syndrome (LGS) compared to those with other epilepsy syndromes using time to treatment failure (retention rate) as the outcome measure.

METHODS

In this retrospective cohort study, characteristics and outcomes of all patients receiving RFM in 2009 and 2010 were recorded. The primary outcome measure was RFM failure, defined as discontinuation of RFM or initiation of an additional antiepileptic therapy. The secondary outcome measure was discontinuation of RFM. Kaplan-Meier method survival curves were generated for time to RFM failure, for all patients and by the presence or absence of Lennox Gastaut Syndrome (LGS). The impact of age, seizure type, fast or slow drug titration, and concomitant therapy with valproate on retention rate were evaluated using Cox regression models.

RESULTS

One hundred thirty-three patients were included, 39 (30%) of whom had LGS. For all patients, the probability of remaining on RFM without additional therapy was 45% at 12 months and 30% at 24 months. LGS diagnosis was an independent predictor of time to RFM failure (HR 0.51, 95% CI 0.31-0.83), with a median time to failure of 18 months in LGS compared to 6 months in all others (p=0.006).

CONCLUSIONS

In a broad population of children with refractory epilepsy, around half will continue taking the medication for at least a year without additional therapy. Patients with LGS are two times more likely to continue RFM without additional therapy compared to those without LGS.

Utility of CT-compatible EEG electrodes in critically ill children

BACKGROUND

Electroencephalographic monitoring is being used with increasing frequency in critically ill children who may require frequent and sometimes urgent brain CT scans. Standard metallic disk EEG electrodes commonly produce substantial imaging artifact, and they must be removed and later reapplied when CT scans are indicated.

OBJECTIVE

To determine whether conductive plastic electrodes caused artifact that limited CT interpretation.

MATERIAL AND METHODS

We describe a retrospective cohort of 13 consecutive critically ill children who underwent 17 CT scans with conductive plastic electrodes during 1 year. CT images were evaluated by a pediatric neuroradiologist for artifact presence, type and severity.

RESULTS

All CT scans had excellent quality images without artifact that impaired CT interpretation except for one scan in which improper wire placement resulted in artifact.

CONCLUSION

Conductive plastic electrodes do not cause artifact limiting CT scan interpretation and may be used in critically ill children to permit concurrent electroencephalographic monitoring and CT imaging.

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).

KCNT1 gain of function in 2 epilepsy phenotypes is reversed by quinidine

OBJECTIVE

Mutations in KCNT1 have been implicated in autosomal dominant nocturnal frontal lobe epilepsy (ADNFLE) and epilepsy of infancy with migrating focal seizures (EIMFS). More recently, a whole exome sequencing study of epileptic encephalopathies identified an additional de novo mutation in 1 proband with EIMFS. We aim to investigate the electrophysiological and pharmacological characteristics of hKCNT1 mutations and examine developmental expression levels.

METHODS

Here we use a Xenopus laevis oocyte-based automated 2-electrode voltage clamp assay. The effects of quinidine (100 and 300 μM) are also tested. Using quantitative reverse transcriptase polymerase chain reaction, the relative levels of mouse brain mKcnt1 mRNA expression are determined.

RESULTS

We demonstrate that KCNT1 mutations implicated in epilepsy cause a marked increase in function. Importantly, there is a significant group difference in gain of function between mutations associated with ADNFLE and EIMFS. Finally, exposure to quinidine significantly reduces this gain of function for all mutations studied.

INTERPRETATION

These results establish direction for a targeted therapy and potentially exemplify a translational paradigm for in vitro studies informing novel therapies in a neuropsychiatric disease.

Assessing the similarity of surface linguistic features related to epilepsy across pediatric hospitals

Objective

The constant progress in computational linguistic methods provides amazing opportunities for discovering information in clinical text and enables the clinical scientist to explore novel approaches to care. However, these new approaches need evaluation. We describe an automated system to compare descriptions of epilepsy patients at three different organizations: Cincinnati Children’s Hospital, the Children’s Hospital Colorado, and the Children’s Hospital of Philadelphia. To our knowledge, there have been no similar previous studies.

Materials and methods

In this work, a support vector machine (SVM)-based natural language processing (NLP) algorithm is trained to classify epilepsy progress notes as belonging to a patient with a specific type of epilepsy from a particular hospital. The same SVM is then used to classify notes from another hospital. Our null hypothesis is that an NLP algorithm cannot be trained using epilepsy-specific notes from one hospital and subsequently used to classify notes from another hospital better than a random baseline classifier. The hypothesis is tested using epilepsy progress notes from the three hospitals.

Results

We are able to reject the null hypothesis at the 95% level. It is also found that classification was improved by including notes from a second hospital in the SVM training sample.

Discussion and conclusion

With a reasonably uniform epilepsy vocabulary and an NLP-based algorithm able to use this uniformity to classify epilepsy progress notes across different hospitals, we can pursue automated comparisons of patient conditions, treatments, and diagnoses across different healthcare settings.

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.

Role of genetics in the diagnosis and treatment of epilepsy

Epilepsy is a heterogeneous group of multifactorial diseases, the vast majority determined by interactions between many genes and environmental factors; however, there are rare epilepsy syndromes that can be caused by a single gene mutation and are inherited according to classical mendelian genetic principles. Finding disease-causing genetic mutations in epilepsy has provided new opportunities for aiding diagnosis and developing therapies. Thus, the discovery of KCNQ2 mutations in benign familial neonatal convulsions, SCN1A mutations in severe myoclonic epilepsy of infancy and in generalized epilepsy with febrile seizures plus, and CHRA4 and CHRB2 mutations in autosomal-dominant nocturnal frontal lobe epilepsy, has led to the establishment of epilepsy as a disorder of ion channel function and, furthermore, has led to the introduction of genetic tests that are available clinically to aid in diagnosis and treatment. At the present time, clinical use of genetic testing in epilepsy is greatest in suspected cases of severe myoclonic epilepsy of infancy, generalized epilepsy with febrile seizures plus, atypical cases of benign familial neonatal convulsions and 'occult' cases of autosomal-dominant nocturnal frontal lobe epilepsy without a family history. Overall, clinical use is limited by the low number of documented disease-associated mutations and the uncertain clinical significance of many test results. Further elucidation of the relationship between gene mutations and channel function will add value to genetic testing in the future, as will better characterization of the association between gene mutations and clinical phenotypes.

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.

Brain tumor presenting as somnambulism in an adolescent

BACKGROUND

Sleepwalking is typically a benign and self-limited non-rapid eye movement parasomnia of childhood.

PATIENT

We describe an unusual 15-year-old boy referred to our sleep center for new-onset sleepwalking.

RESULTS

An overnight polysomnogram was normal from a respiratory standpoint, but a concurrent extended electroencephalogram montage showed frequent epileptiform discharges from the right parietal-temporal region and two electroclinical seizures arising from the right-frontal-central-temporal region during sleep. Magnetic resonance imaging scan revealed a right parasagittal parietal region lesion consistent with a low-grade neoplasm, and surgical resection of the lesion demonstrated a right parietal dysembryoplastic neuroepithelial tumor. Complex partial seizures and sleepwalking remitted completely with anticonvulsant therapy following surgery.

CONCLUSIONS

This patient highlights the differential diagnosis of nocturnal events appearing to be typical parasomnias, especially when they arise abruptly at an older age.

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.

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.

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.

The evaluation of treatment-resistant epilepsy

An estimated 10% to 40% of children with epilepsy have treatment-resistant epilepsy. Persistent seizures have negative psychosocial, behavioral, cognitive, and financial consequences and are associated with an increased mortality rate. Accurate syndromic and etiologic diagnoses are of vital importance because they may guide medical and/or surgical decision making. Revisitation of the history to confirm the diagnosis of epilepsy and the appropriateness of medication trials to date is vital. Routine imaging should include structural magnetic resonance imaging (MRI) with an established epilepsy protocol. In the setting of a normal previous MRI, repeat imaging may be indicated and may be supplemented with other imaging modalities. The admission for prolonged inpatient video-encephalographic monitoring may lead to a revision of a pre-existing diagnosis. Laboratory evaluations should include genetic, metabolic, and infectious/inflammatory studies when indicated. In this review, we discuss the implication of seizure semiology and syndrome classification when searching for an underlying diagnosis in treatment-resistant epilepsy, and will review both basic and more advanced procedures/studies that may aid diagnosis.

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.

Common data elements in epilepsy research: development and implementation of the NINDS epilepsy CDE project

The Common Data Element (CDE) Project was initiated in 2006 by the National Institute of Neurological Disorders and Stroke (NINDS) to develop standards for performing funded neuroscience-related clinical research. CDEs are intended to standardize aspects of data collection; decrease study start-up time; and provide more complete, comprehensive, and equivalent data across studies within a particular disease area. Therefore, CDEs will simplify data sharing and data aggregation across NINDS-funded clinical research, and where appropriate, facilitate the development of evidenced-based guidelines and recommendations. Epilepsy-specific CDEs were established in nine content areas: (1) Antiepileptic Drugs (AEDs) and Other Antiepileptic Therapies (AETs), (2) Comorbidities, (3) Electrophysiology, (4) Imaging, (5) Neurological Exam, (6) Neuropsychology, (7) Quality of Life, (8) Seizures and Syndromes, and (9) Surgery and Pathology. CDEs were developed as a dynamic resource that will accommodate recommendations based on investigator use, new technologies, and research findings documenting emerging critical disease characteristics. The epilepsy-specific CDE initiative can be viewed as part of the larger international movement toward "harmonization" of clinical disease characterization and outcome assessment designed to promote communication and research efforts in epilepsy. It will also provide valuable guidance for CDE improvement during further development, refinement, and implementation. This article describes the NINDS CDE Initiative, the process used in developing Epilepsy CDEs, and the benefits of CDEs for the clinical investigator and NINDS.

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.

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.

Magnetoencephalography for pediatric epilepsy: how we do it

Magnetoencephalography (MEG) is increasingly being used in the preoperative evaluation of pediatric patients with epilepsy. The ability to noninvasively localize ictal onset zones (IOZ) and their relationships to eloquent functional cortex allows the pediatric epilepsy team to more accurately assess the likelihood of postoperative seizure freedom, while more precisely prognosticating the potential functional deficits that may be expected from resective surgery. Confirmation of clinically suggested multifocality may result in a recommendation against resective surgery because the probability of seizure freedom will be low. Current paradigms for motor and somatosensory testing are robust. Paradigms allowing localization of those regions necessary for competent language function, though promising, are under continuous optimization. MR imaging white matter trajectory data, created from diffusion tensor imaging obtained in the same setting as the localization brain MR imaging, provide ancillary information regarding connectivity of the IOZ to sites of rapid secondary spread and the spatial relationship of the IOZ to functionally important white matter bundles, such as the corticospinal tracts. A collaborative effort between neuroradiology, neurology, neurosurgery, neuropsychology, technology, and physics ensures successful implementation of MEG within a pediatric epilepsy program.