Tammy N. Tsuchida

The American clinical neurophysiology society's guideline on continuous electroencephalography monitoring in neonates

This article offers the preferred methods and indications for longterm, conventional electroencephalography (EEG) monitoring for selected, high-risk neonates of postmenstrual age less than 48 weeks. The authors recognize that there may be significant practical barriers to the implementation of these recommendations for many caregivers and institutions, particularly with regard to the availability of equipment, and technical and interpretive personnel. A wide range of clinical circumstances dictates the implementation of EEG monitoring, frequency of EEG review, and the subsequent treatment of seizures or EEG background abnormalities detected by neonatal EEG. Consequently, this article should be considered as an expression of idealized goals and not as a mandated standard of care.

Consensus Statement on Continuous EEG in Critically Ill Adults and Children, Part I: Indications

Introduction: Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. Methods: The Critical Care Continuous EEG Task Force of the American Clinical Neurophysiology Society developed expert consensus recommendations on the use of CCEEG in critically ill adults and children. Recommendations: The consensus panel recommends CCEEG for diagnosis of nonconvulsive seizures, nonconvulsive status epilepticus, and other paroxysmal events, and for assessment of the efficacy of therapy for seizures and status epilepticus. The consensus panel suggests CCEEG for identification of ischemia in patients at high risk for cerebral ischemia; for assessment of level of consciousness in patients receiving intravenous sedation or pharmacologically induced coma; and for prognostication in patients after cardiac arrest. For each indication, the consensus panel describes the patient populations for which CCEEG is indicated, evidence supporting use of CCEEG, utility of video and quantitative EEG trends, suggested timing and duration of CCEEG, and suggested frequency of review and interpretation. Conclusion: CCEEG has an important role in detection of secondary injuries such as seizures and ischemia in critically ill adults and children with altered mental status.

American clinical neurophysiology society standardized EEG terminology and categorization for the description of continuous EEG monitoring in neonates: report of the American Clinical Neurophysiology Society critical care monitoring committee.

BACKGROUNDCritically ill neonates are at high risk for adverse neurologic sequelae, but the bedside evaluation of a neonates neurologic status, especially cortical functioning, is extremely limited. In such circumstances, continuous video EEG provides particularly useful information about brain

Summary of recommendations for the management of infantile seizures: Task Force Report for the ILAE Commission of Pediatrics

Evidence‐based guidelines, or recommendations, for the management of infants with seizures are lacking. A Task Force of the Commission of Pediatrics developed a consensus document addressing diagnostic markers, management interventions, and outcome measures for infants with seizures. Levels of evidence to support recommendations and statements were assessed using the American Academy of Neurology Guidelines and the Grading of Recommendations Assessment, Development and Evaluation (GRADE) system. The report contains recommendations for different levels of care, noting which would be regarded as standard care, compared to optimal care, or “state of the art” interventions. The incidence of epilepsy in the infantile period is the highest of all age groups (strong evidence), with epileptic spasms the largest single subgroup and, in the first 2 years of life, febrile seizures are the most commonly occurring seizures. Acute intervention at the time of a febrile seizure does not alter the risk for subsequent epilepsy (class 1 evidence). The use of antipyretic agents does not alter the recurrence rate (class 1 evidence), and there is no evidence to support initiation of regular antiepileptic drugs for simple febrile seizures (class 1 evidence). Infants with abnormal movements whose routine electroencephalography (EEG) study is not diagnostic, would benefit from video‐EEG analysis, or home video to capture events (expert opinion, level U recommendation). Neuroimaging is recommended at all levels of care for infants presenting with epilepsy, with magnetic resonance imaging (MRI) recommended as the standard investigation at tertiary level (level A recommendation). Genetic screening should not be undertaken at primary or secondary level care (expert opinion). Standard care should permit genetic counseling by trained personal at all levels of care (expert opinion). Genetic evaluation for Dravet syndrome, and other infantile‐onset epileptic encephalopathies, should be available in tertiary care (weak evidence, level C recommendation). Patients should be referred from primary or secondary to tertiary level care after failure of one antiepileptic drug (standard care) and optimal care equates to referral of all infants after presentation with a seizure (expert opinion, level U evidence). Infants with recurrent seizures warrant urgent assessment for initiation of antiepileptic drugs (expert opinion, level U recommendation). Infantile encephalopathies should have rapid introduction and increment of antiepileptic drug dosage (expert opinion, level U recommendation). There is no high level evidence to support any particular current agents for use in infants with seizures. For focal seizures, levetiracetam is effective (strong evidence); for generalized seizures, weak evidence supports levetiracetam, valproate, lamotrigine, topiramate, and clobazam; for Dravet syndrome, strong evidence supports that stiripentol is effective (in combination with valproate and clobazam), whereas weak evidence supports that topiramate, zonisamide, valproate, bromide, and the ketogenic diet are possibly effective; and for Ohtahara syndrome, there is weak evidence that most antiepileptic drugs are poorly effective. For epileptic spasms, clinical suspicion remains central to the diagnosis and is supported by EEG, which ideally is prolonged (level C recommendation). Adrenocorticotropic hormone (ACTH) is preferred for short‐term control of epileptic spasms (level B recommendation), oral steroids are probably effective in short‐term control of spasms (level C recommendation), and a shorter interval from the onset of spasms to treatment initiation may improve long‐term neurodevelopmental outcome (level C recommendation). The ketogenic diet is the treatment of choice for epilepsy related to glucose transporter 1 deficiency syndrome and pyruvate dehydrogenase deficiency (expert opinion, level U recommendation). The identification of patients as potential candidates for epilepsy surgery should be part of standard practice at primary and secondary level care. Tertiary care facilities with experience in epilepsy surgery should undertake the screening for epilepsy surgical candidates (level U recommendation). There is insufficient evidence to conclude if there is benefit from vagus nerve stimulation (level U recommendation). The key recommendations are summarized into an executive summary. The full report is available as Supporting Information. This report provides a comprehensive foundation of an approach to infants with seizures, while identifying where there are inadequate data to support recommended practice, and where further data collection is needed to address these deficits.

Consensus Statement on Continuous EEG in Critically Ill Adults and Children, Part II: Personnel, Technical Specifications and Clinical Practice

Introduction: Critical Care Continuous EEG (CCEEG) is a common procedure to monitor brain function in patients with altered mental status in intensive care units. There is significant variability in patient populations undergoing CCEEG and in technical specifications for CCEEG performance. Methods: The Critical Care Continuous EEG Task Force of the American Clinical Neurophysiology Society developed expert consensus recommendations on the use of CCEEG in critically ill adults and children. Recommendations: The consensus panel describes the qualifications and responsibilities of CCEEG personnel including neurodiagnostic technologists and interpreting physicians. The panel outlines required equipment for CCEEG, including electrodes, EEG machine and amplifier specifications, equipment for polygraphic data acquisition, EEG and video review machines, central monitoring equipment, and network, remote access, and data storage equipment. The consensus panel also describes how CCEEG should be acquired, reviewed and interpreted. The panel suggests methods for patient selection and triage; initiation of CCEEG; daily maintenance of CCEEG; electrode removal and infection control; quantitative EEG techniques; EEG and behavioral monitoring by non-physician personnel; review, interpretation, and reports; and data storage protocols. Conclusion: Recommended qualifications for CCEEG personnel and CCEEG technical specifications will facilitate standardization of this emerging technology.

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.

Novel SCN1A Mutation in a Proband With Malignant Migrating Partial Seizures of Infancy

OBJECTIVE To characterize a novel SCN1A mutation in a proband with malignant migrating partial seizures of infancy. DESIGN Genomic DNA was isolated from blood and submitted for commercial testing. The identified missense mutation was confirmed in brain DNA obtained at autopsy. Genomic DNA from the brain of the proband was analyzed by comparative genome hybridization, and the coding exons of SCN9A were amplified. Quantitation studies of the mutant transcript were performed. SETTING Childrens National Medical Center and Yale University School of Medicine. PROBAND: A full-term female infant who experienced seizure onset at age 10 weeks, with progression of hemiclonic, apneic, and multifocal migrating partial seizures leading to recurrent status epilepticus and death at age 9 months. MAIN OUTCOME MEASURES Electroencephalographic and magnetic resonance imaging results, quantitative RNA expression, and secondary mutation test results. RESULTS The heterozygous missense mutation c.C5006C>A was identified by sequencing genomic DNA from blood and was confirmed in brain DNA. The resulting amino acid substitution p.A1669E alters an evolutionarily conserved residue in an intracellular linker of domain 4 of the SCN1A sodium channel protein Na(v)1.1. The mutant transcript is found to be expressed at levels comparable to the wild-type allele in brain RNA. No variation in copy number was detected in the chromosome region 2q24 containing SCN1A or elsewhere in the genome. No mutations were detected in the linked sodium channel gene SCN9A, which has been reported to act as a modifier of SCN1A mutations. CONCLUSION This report expands the spectrum of SCN1A epileptic channelopathies to include malignant migrating partial seizures of infancy.

Results of phase II levetiracetam trial following acute head injury in children at risk for posttraumatic epilepsy

Posttraumatic seizures develop in up to 20% of children following severe traumatic brain injury (TBI). Children ages 6–17 years with one or more risk factors for the development of posttraumatic epilepsy, including presence of intracranial hemorrhage, depressed skull fracture, penetrating injury, or occurrence of posttraumatic seizure were recruited into this phase II study. Treatment subjects received levetiracetam 55 mg/kg/day, b.i.d., for 30 days, starting within 8 h postinjury. The recruitment goal was 20 treated patients. Twenty patients who presented within 8–24 h post‐TBI and otherwise met eligibility criteria were recruited for observation. Follow‐up was for 2 years. Forty‐five patients screened within 8 h of head injury met eligibility criteria and 20 were recruited into the treatment arm. The most common risk factor present for pediatric inclusion following TBI was an immediate seizure. Medication compliance was 95%. No patients died; 19 of 20 treatment patients were retained and one observation patient was lost to follow‐up. The most common severe adverse events in treatment subjects were headache, fatigue, drowsiness, and irritability. There was no higher incidence of infection, mood changes, or behavior problems among treatment subjects compared to observation subjects. Only 1 (2.5%) of 40 subjects developed posttraumatic epilepsy (defined as seizures >7 days after trauma). This study demonstrates the feasibility of a pediatric posttraumatic epilepsy prevention study in an at‐risk traumatic brain injury population. Levetiracetam was safe and well tolerated in this population. This study sets the stage for implementation of a prospective study to prevent posttraumatic epilepsy in an at‐risk population.

KCNQ2 encephalopathy: Features, mutational hot spots, and ezogabine treatment of 11 patients

Objective: To advance the understanding of KCNQ2 encephalopathy genotype–phenotype relationships and to begin to assess the potential of selective KCNQ channel openers as targeted treatments. Methods: We retrospectively studied 23 patients with KCNQ2 encephalopathy, including 11 treated with ezogabine (EZO). We analyzed the genotype–phenotype relationships in these and 70 previously described patients. Results: The mean seizure onset age was 1.8 ± 1.6 (SD) days. Of the 20 EEGs obtained within a week of birth, 11 showed burst suppression. When new seizure types appeared in infancy (15 patients), the most common were epileptic spasms (n = 8). At last follow-up, seizures persisted in 9 patients. Development was delayed in all, severely in 14. The KCNQ2 variants identified introduced amino acid missense changes or, in one instance, a single residue deletion. They were clustered in 4 protein subdomains predicted to poison tetrameric channel functions. EZO use (assessed by the treating physicians and parents) was associated with improvement in seizures and/or development in 3 of the 4 treated before 6 months of age, and 2 of the 7 treated later; no serious side effects were observed. Conclusions: KCNQ2 variants cause neonatal-onset epileptic encephalopathy of widely varying severity. Pathogenic variants in epileptic encephalopathy are clustered in “hot spots” known to be critical for channel activity. For variants causing KCNQ2 channel loss of function, EZO appeared well tolerated and potentially beneficial against refractory seizures when started early. Larger, prospective studies are needed to enable better definition of prognostic categories and more robust testing of novel interventions. Classification of evidence: This study provides Class IV evidence that EZO is effective for refractory seizures in patients with epilepsy due to KCNQ2 encephalopathy.

New-onset afebrile seizures in infants Role of neuroimaging

Objective: To investigate the presenting characteristics of new-onset afebrile seizures in infants (age 1–24 months) and the yield of neuroimaging. Methods: Prospective data were obtained from a standardized evaluation and management plan mandated by a critical care pathway. A total of 317 infants presented with new-onset afebrile seizures between 2001 and 2007. EEG was performed on 90.3%, head CT was obtained on 94%, and MRI was obtained on 57.4%. Results: We found half of the infants had partial features to their seizures, yet evidence for primary generalized seizures was rare. The majority had more than 1 seizure upon presentation. Seizures in this age group tended to be brief, with 44% lasting less than 1 minute. EEG abnormalities were found in half. One-third of CTs were abnormal, with 9% of all CTs requiring acute medical management. Over half of MRIs were abnormal, with cerebral dysgenesis being the most common abnormality (p < 0.05). One-third of normal CTs had a subsequent abnormal MRI—only 1 resulted in altered medical management. Conclusions: Infantile seizures are usually brief, but commonly recurrent, and strong consideration should be made for inpatient observation. Acute imaging with CT can alter management in a small but important number of infants. Due to the superior yield, strong consideration for MRI should be given for all infants, as primary generalized seizures are rare, and there is a high rate of cerebral dysgenesis.