ANK2 loss-of-function variants are associated with epilepsy, and lead to impaired axon initial segment plasticity and hyperactive network activity in hiPSC-derived neuronal networks.

PURPOSE: To characterize a novel neurodevelopmental syndrome due to loss-of-function (LoF) variants in Ankyrin 2 (ANK2), and to explore the effects on neuronal network dynamics and homeostatic plasticity in human-induced pluripotent stem cell-derived neurons. METHODS: We collected clinical and molecular data of 12 individuals with heterozygous de novo LoF variants in ANK2. We generated a heterozygous LoF allele of ANK2 using CRISPR/Cas9 in human-induced pluripotent stem cells (hiPSCs). HiPSCs were differentiated into excitatory neurons, and we measured their spontaneous electrophysiological responses using micro-electrode arrays (MEAs). We also characterized their somatodendritic morphology and axon initial segment (AIS) structure and plasticity. RESULTS: We found a broad neurodevelopmental disorder (NDD), comprising intellectual disability, autism spectrum disorders and early onset epilepsy. Using MEAs, we found that hiPSC-derived neurons with heterozygous LoF of ANK2 show a hyperactive and desynchronized neuronal network. ANK2-deficient neurons also showed increased somatodendritic structures and altered AIS structure of which its plasticity is impaired upon activity-dependent modulation. CONCLUSIONS: Phenotypic characterization of patients with de novo ANK2 LoF variants defines a novel NDD with early onset epilepsy. Our functional in vitro data of ANK2-deficient human neurons show a specific neuronal phenotype in which reduced ANKB expression leads to hyperactive and desynchronized neuronal network activity, increased somatodendritic complexity and AIS structure and impaired activity-dependent plasticity of the AIS.

A multi-center comparison of surgical techniques for corpus Callosotomy in pediatric drug-resistant epilepsy.

OBJECTIVES: Corpus callosotomy (CC) is used to reduce seizures, primarily in patients with generalized drug-resistant epilepsy (DRE). The invasive nature of the procedure contributes to underutilization despite its potential superiority to other palliative procedures. The goal of this study was to use a multi-institutional epilepsy surgery database to characterize the use of CC across participating centers. METHODS: Data were acquired from the Pediatric Epilepsy Research Consortium (PERC) Surgery Database, a prospective observational study collecting data on children 0-18 years referred for surgical evaluation of DRE across 22 U.S. pediatric epilepsy centers. Patient, epilepsy, and surgical characteristics were collected across multiple CC modalities. Outcomes and complications were recorded and analyzed statistically. RESULTS: Eighty-three patients undergoing 85 CC procedures at 14 participating epilepsy centers met inclusion criteria. Mean age at seizure onset was 2.3 years (0-9.4); mean age for Phase I evaluation and surgical intervention were 9.45 (.1-20) and 10.46 (.2-20.6) years, respectively. Generalized seizure types were the most common (59%). Complete CC was performed in 88%. The majority of CC procedures (57%) were via open craniotomy, followed by laser interstitial thermal therapy (LiTT) (20%) and mini-craniotomy/endoscopic (mc/e) (22%). Mean operative times were significantly longer for LiTT, whereas mean estimated blood loss was greater in open cases. Complications occurred in 11 cases (13%) and differed significantly between surgical techniques (p < .001). There was no statistically significant difference in length of postoperative stay across approaches. Mean follow-up was 12.8 months (range 1-39). Favorable Engel outcomes were experienced by 37 (78.7%) of the patients who underwent craniotomy, 10 (58.8%) with LiTT, and 12 (63.2%) with mc/e; these differences were not statistically significant. SIGNIFICANCE: CC is an effective surgical modality for children with DRE. Regardless of surgical modality, complication rates are acceptable and seizure outcomes generally favorable. Newer, less-invasive, surgical approaches may lead to increased adoption of this efficacious therapeutic option for pediatric DRE.

Surgical evaluation in children <3 years of age with drug-resistant epilepsy: Patient characteristics, diagnostic utilization, and potential for treatment delays.

OBJECTIVE: Drug-resistant epilepsy (DRE) occurs at higher rates in children <3 years old. Epilepsy surgery is effective, but rarely utilized in young children despite developmental benefits of early seizure freedom. The present study aims to identify unique patient characteristics and evaluation strategies in children <3 years old who undergo epilepsy surgery evaluation as a means to assess contributors and potential solutions to health care disparities in this group. METHODS: The Pediatric Epilepsy Research Consortium Epilepsy Surgery Database, a multicentered, cross-sectional collaboration of 21 US pediatric epilepsy centers, collects prospective data on children <18 years of age referred for epilepsy surgery evaluation. We compared patient characteristics, diagnostic utilization, and surgical treatment between children <3 years old and those older undergoing initial presurgical evaluation. We evaluated patient characteristics leading to delayed referral (>1 year) after DRE diagnosis in the very young. RESULTS: The cohort included 437 children, of whom 71 (16%) were <3 years of age at referral. Children evaluated before the age of 3 years more commonly had abnormal neurological examinations (p = .002) and daily seizures (p = .001). At least one ancillary test was used in 44% of evaluations. Fifty-nine percent were seizure-free following surgery (n = 34), with 35% undergoing limited focal resections. Children with delayed referrals more often had focal aware (p < .001) seizures and recommendation for palliative surgeries (p < .001). SIGNIFICANCE: There are relatively few studies of epilepsy surgery in the very young. Surgery is effective, but may be disproportionally offered to those with severe presentations. Relatively low utilization of ancillary testing may contribute to reduced surgical therapy for those without evident lesions on magnetic resonance imaging. Despite this, a sizeable portion of patients have favorable outcome after focal epilepsy surgery resections.

Focal cortical malformations in children with early infantile epilepsy and PCDH19 mutations: case report.

In this case report we assess the occurrence of cortical malformations in children with early infantile epilepsy associated with variants of the gene protocadherin 19 (PCDH19). We describe the clinical course, and electrographic, imaging, genetic, and neuropathological features in a cohort of female children with pharmacoresistant epilepsy. All five children (mean age 10y) had an early onset of epilepsy during infancy and a predominance of fever sensitive seizures occurring in clusters. Cognitive impairment was noted in four out of five patients. Radiological evidence of cortical malformations was present in all cases and, in two patients, validated by histology. Sanger sequencing and Multiplex Ligation-dependent Probe Amplification analysis of PCDH19 revealed pathogenic variants in four patients. In one patient, array comparative genomic hybridization showed a microdeletion encompassing PCDH19. We propose molecular testing and analysis of PCDH19 in patients with pharmacoresistant epilepsy, with onset in early infancy, seizures in clusters, and fever sensitivity. Structural lesions are to be searched in patients with PCDH19 pathogenic variants. Further, PCDH19 analysis should be considered in epilepsy surgery evaluation even in the presence of cerebral structural lesions. WHAT THIS PAPER ADDS: Focal cortical malformations and monogenic epilepsy syndromes may coexist. Structural lesions are to be searched for in patients with protocadherin 19 (PCDH19) pathogenic variants with refractory focal seizures.

Clinical and Electroencephalographic Characteristics of Infantile-Onset Epilepsies Caused by Genetic Mutations.

OBJECTIVES: To determine whether certain characteristic electroencephalography (EEG) features are indicative of a genetic cause in early-life epilepsy. STUDY DESIGN: We enrolled a total of 100 patients with infantile-onset (<3 years) epilepsy due to known genetic cause (n = 50) and nongenetic cause (acquired, structural, or unknown, n = 50). The genetic group was classified into synaptopathies, channelopathies, mTOR (mammalian target of rapamycin)-opathies, and chromosomal abnormalities. The nongenetic group included epilepsy of unknown cause and structural abnormalities such as brain tumor, focal cortical dysplasia and encephalomalacia. The clinical features, magnetic resonance imaging, and video EEG obtained before 3 years of age and again at follow-up were reviewed. Specifically, the background rhythms and patterns of interictal epileptiform discharges were analyzed to define the EEG characteristics. RESULTS: The genetic group was more likely to have seizure recurrence beyond infancy and significant developmental delay (P <.01). The genetic and nongenetic groups showed different EEG patterns in the initial EEGs that persisted in follow-up EEGs. Diffuse slowing with pleomorphic focal/multifocal epileptiform discharges were present more often in the genetic (86%) compared with the nongenetic group (20%) in the initial EEGs (P <.01). The last available follow-up EEG features were similar (81% in genetic versus 17% in nongenetic) to the EEG performed prior to 3 years of age. CONCLUSIONS: Our findings suggest a simple guide for genetic screening in children with early-onset epilepsy. Genetic testing may be indicated and useful in infants with delayed development, no obvious cause, and significant EEG background slowing with pleomorphic focal or multifocal epileptiform discharges.

Pediatric Palliative Epilepsy Surgery: A Report From the Pediatric Epilepsy Research Consortium (PERC) Surgery Database.

BACKGROUND: Epilepsy surgery is an underutilized resource for children with drug-resistant epilepsy. Palliative and definitive surgical options can reduce seizure burden and improve quality of life. Palliative epilepsy surgery is often seen as a "last resort" compared to definitive surgical options. We compare patient characteristics between palliative and definitive epilepsy surgical patients and present palliative surgical outcomes from the Pediatric Epilepsy Research Consortium surgical database. METHODS: The Pediatric Epilepsy Research Consortium Epilepsy Surgery database is a prospective registry of patients aged 0-18 years undergoing evaluation for epilepsy surgery at 20 pediatric epilepsy centers. We included all children with completed surgical therapy characterized as definitive or palliative. Demographics, epilepsy type, age of onset, age at referral, etiology of epilepsy, treatment history, time-to-referral/evaluation, number of failed anti-seizure medications (ASMs), imaging results, type of surgery, and postoperative outcome were acquired. RESULTS: Six hundred forty patients undergoing epilepsy surgery were identified. Patients undergoing palliative procedures were younger at seizure onset (median: 2.1 vs 4 years, P= 0.0008), failed more ASM trials before referral for presurgical evaluation (P=<0.0001), and had longer duration of epilepsy before referral for surgery (P=<0.0001). During presurgical evaluation, patients undergoing palliative surgery had shorter median duration of video-EEG data collected (P=0.007) but number of cases where ictal data were acquired was similar between groups. The most commonly performed palliative procedure was corpus callosotmy (31%), followed by lobectomy (21%) and neuromodulation (82% responsive neurostimulation vs 18% deep brain stimulation). Palliative patients were further categorized into traditionally palliative procedures vs traditionally definitive procedures. The majority of palliative patients had 50% reduction or better in seizure burden. Seizure free outcomes were significantly higher among those with traditional definitive surgeries, 41% (95% confidence interval: 26% to 57%) compared with traditional palliative surgeries and 9% (95% confidence interval: 2% to 17%). Rate of seizure freedom was 46% at 24 months or greater of follow-up in the traditional definitive group. CONCLUSIONS: Patients receiving palliative epilepsy surgery trialed more ASMs, were referred later after becoming drug resistant, and had longer gaps between drug resistance and epilepsy surgery compared with patients undergoing definitive epilepsy surgery. The extent of surgical evaluation is impacted if surgery is thought to be palliative. A majority of palliative surgery patients achieved >50% seizure reduction at follow-up, both in groups that received traditionally palliative and traditionally definitive surgical procedures. Palliative surgical patients can achieve greater seizure control and should be referred to an epilepsy surgery center promptly after failing two appropriate anti-seizure medications.

Long-term neuropsychological outcomes in children with febrile infection-related epilepsy syndrome (FIRES) treated with anakinra.

Background: Febrile-infection related epilepsy syndrome (FIRES) is a rare epilepsy syndrome in which a previously healthy individual develops refractory status epilepticus in the setting of a preceding febrile illness. There are limited data regarding detailed long-term outcomes. This study aims to describe the long-term neuropsychological outcomes in a series of pediatric patients with FIRES. Methods: This is a retrospective multi-center case series of pediatric patients with a diagnosis of FIRES treated acutely with anakinra who had neuropsychological testing at least 12 months after status epilepticus onset. Each patient underwent comprehensive neuropsychological evaluation as part of routine clinical care. Additional data collection included the acute seizure presentation, medication exposures, and outcomes. Results: There were six patients identified with a median age of 11.08 years (IQR: 8.19-11.23) at status epilepticus onset. Anakinra initiation was a median of 11 days (IQR: 9.25-13.50) after hospital admission. All patients had ongoing seizures and none of the patients returned to baseline cognitive function with a median follow-up of 40 months (IQR 35-51). Of the five patients with serial full-scale IQ testing, three demonstrated a decline in scores over time. Testing results revealed a diffuse pattern of deficits across domains and all patients required special education and/or accommodations for academic learning. Conclusions: Despite treatment with anakinra, neuropsychological outcomes in this series of pediatric patients with FIRES demonstrated ongoing diffuse neurocognitive impairment. Future research will need to explore the predictors of long-term neurocognitive outcomes in patients with FIRES and to evaluate if acute treatment interventions improve these outcomes.

A multidisciplinary approach and consensus statement to establish standards of care for Angelman syndrome.

BACKGROUND: Angelman syndrome (AS) is a rare neurogenetic disorder present in approximately 1/12,000 individuals and characterized by developmental delay, cognitive impairment, motor dysfunction, seizures, gastrointestinal concerns, and abnormal electroencephalographic background. AS is caused by absent expression of the paternally imprinted gene UBE3A in the central nervous system. Disparities in the management of AS are a major problem in preparing for precision therapies and occur even in patients with access to experts and recognized clinics. AS patients receive care based on collective provider experience due to limited evidence-based literature. We present a consensus statement and comprehensive literature review that proposes a standard of care practices for the management of AS at a critical time when therapeutics to alter the natural history of the disease are on the horizon. METHODS: We compiled the key recognized clinical features of AS based on consensus from a team of specialists managing patients with AS. Working groups were established to address each focus area with committees comprised of providers who manage >5 individuals. Committees developed management guidelines for their area of expertise. These were compiled into a final document to provide a framework for standardizing management. Evidence from the medical literature was also comprehensively reviewed. RESULTS: Areas covered by working groups in the consensus document include genetics, developmental medicine, psychology, general health concerns, neurology (including movement disorders), sleep, psychiatry, orthopedics, ophthalmology, communication, early intervention and therapies, and caregiver health. Working groups created frameworks, including flowcharts and tables, to help with quick access for providers. Data from the literature were incorporated to ensure providers had review of experiential versus evidence-based care guidelines. CONCLUSION: Standards of care in the management of AS are keys to ensure optimal care at a critical time when new disease-modifying therapies are emerging. This document is a framework for providers of all familiarity levels.

Measurable outcomes for pediatric epileptic encephalopathy: a single-center experience with corticosteroid therapy.

Corticosteroids are commonly used to treat refractory epilepsy in children, but the heterogeneity of the population and lack of standardized outcome measures have limited understanding of their effectiveness. We conducted a single-center study of corticosteroids for epileptic encephalopathy to (a) identify domains for measurement and estimate potential effect sizes, (b) characterize heterogeneity, and (c) identify outcomes that may need better tools for measurement. In this retrospective single-center cohort study, children with epileptic encephalopathy (excluding infantile spasms) were treated with a standardized course of oral dexamethasone or IV methylprednisolone. Long-term video electroencephalography (EEG) was assessed via novel ordinal scales for five features: seizure semiology/burden, epileptiform activity, slowing, organization, and sleep architecture. We abstracted parental assessment of functional domains (i.e., cognition) from the medical records. Pre-treatment and post-treatment EEG features, functional domains, and treatment regimens were compared. Thirty-five children with refractory epilepsy were included. Overall, 16/35 (46%) of individuals had a >50% reduction in seizure frequency from the pre-treatment EEG to the initial post-treatment EEG. In particular, tonic seizures (in a subset of 23 children) were reduced (24-hour tonic seizure count pre-treatment was 8 [4-13] and 3 [1-5] post-treatment EEG#1, p=0.04). For follow-up post-treatment EEGs, there was: (1) better formation of sleep spindles (37% normal pre-treatment to 63% normal post-treatment; p=0.04); and (2) improvement in parental reported cognition (in 43%). Improved cognition was the only outcome that differed between the dexamethasone and methylprednisolone treated groups (58% for dexamethasone [n=11/19] vs. 25% for methylprednisolone [n=4/16]; p=0.03). Large studies should be powered to detect reductions in seizures (particularly tonic as we identified a 2.6-fold reduction), improved EEG organization, and improved sleep architecture (21 percentage points). Cognitive improvements following steroid treatment, reported by parents, should be quantified and fully characterized in future work.

Anakinra usage in febrile infection related epilepsy syndrome: an international cohort.

Febrile-infection related epilepsy syndrome (FIRES) is a devastating neurological condition characterized by a febrile illness preceding new onset refractory status epilepticus (NORSE). Increasing evidence suggests innate immune dysfunction as a potential pathological mechanism. We report an international retrospective cohort of 25 children treated with anakinra, a recombinant interleukin-1 receptor antagonist, as an immunomodulator for FIRES. Anakinra was potentially safe with only one child discontinuing therapy due to infection. Earlier anakinra initiation was associated with shorter duration of mechanical ventilation, ICU and hospital length of stay. Our retrospective data lay the groundwork for prospective consensus-driven cohort studies of anakinra in FIRES.

Successful management of refractory neonatal seizures with midazolam.

Seizures are indicative of underlying neurologic dysfunction in neonates. Repeated seizures may be deleterious to the brain even without disturbances of ventilation or perfusion. First-line antiepileptic drugs such as phenobarbital and phenytoin are not very effective in controlling seizures in neonates. Rapid control of status epilepticus with midazolam has been demonstrated in 2 previous studies with complete clinical and electrographic response in neonates who did not respond to phenobarbital and phenytoin. We report our experience with 3 neonates with status epilepticus. Seizures in all 3 neonates did not respond to phenobarbital and phenytoin but responded to midazolam infusion. Midazolam may be considered a safe and effective antiepileptic drug in refractory neonatal seizures of diverse etiologies.

How do we diagnose and treat epilepsy with myoclonic-atonic seizures (Doose syndrome)? Results of the Pediatric Epilepsy Research Consortium survey.

OBJECTIVE: To obtain and assess opinions on EMAS diagnostic criteria, recommended investigations, and therapeutic options, from a large group of physicians who care for children with EMAS. METHODS: The EMAS focus group of PERC created a survey to assess the opinions of pediatric neurologists who care for children with EMAS regarding diagnosis and treatment of this condition, which was sent to members of PERC, AES, and CNS. A Likert scale was used to assess the respondents' opinions on the importance of diagnostic and exclusion criteria (five point scale), investigations (four point scale), and treatment (six point scale) of EMAS. Inclusion/exclusion criteria were then classified as critical, strong, or modest. Investigations were classified as essential, recommended, or possible. Therapies were classified as first line, beneficial, indeterminate benefit, or contraindicated. RESULTS: Survey results from the 76 participants determined the following: EMAS inclusion criteria: history suggestive of MAS (critical), recorded or home video suggestive of MAS, generalized discharges on inter-ictal EEG, normal neuroimaging, normal development prior to seizure onset (strong). EMAS exclusionary criteria: epileptic spasms, abnormal neuroimaging, focal abnormal exam, seizure onset six years (strong). RECOMMENDED INVESTIGATIONS: EEG and MRI (essential), amino acids, organic acids, fatty acid/acylcarnitine profile, microarray, genetic panel, lactate/pyruvate, CSF and serum glucose/lactate (strong). RECOMMENDED TREATMENTS: Valproic acid (first line), topiramate, zonisamide, levetiracetam, benzodiazepines, and dietary therapies (beneficial). SIGNIFICANCE: To date, no similar surveys have been published, even though early syndrome identification and initiation of effective treatment have been associated with improved outcome in EMAS. Medications that exacerbate seizures in EMAS have also been identified. This survey identified critical and preferred diagnostic electro clinical features, investigations, and treatments for EMAS. It will guide future research and is a crucial first step in defining specific diagnostic criteria, recommended evaluation, and most effective therapies for EMAS.

Seizure Outcomes in Children Following Electrocorticography-Guided Single-Stage Surgical Resection.

BACKGROUND: In children with abnormal imaging, single-stage epilepsy surgery is an attractive alternative to the two-stage approach that relies on invasive recording of seizures. Implanted electrodes carry risks of their own and extend hospitalization, but the efficacy of one-stage resections in a variety of pathologies and cerebral locations is not well established. We report our center's experience with single-stage epilepsy surgery guided by intraoperative electrocorticography (ECoG). METHODS: We retrospectively analyzed 130 consecutive patients who underwent single-stage epilepsy surgery before age 19 years and had at least a two-year follow-up. Intraoperative ECoG was available for review in 113. Patients were considered seizure-free if they were continuously Engel Class I up to the two-year postoperative mark. ECoG findings were classified according to the presence of interictal attenuation, spikes, both, or neither. Complications and hospital length of stay were evaluated. RESULTS: Eighty percent of 130 patients were seizure-free at two years. All but one had an abnormal MRI. Patients with tumor had a better seizure outcome than patients with cortical malformation. Frontal resections had worse outcome, especially among tumors. Intraoperative ECoG revealed both attenuation and spikes in 48%, attenuation only in 23%, spikes only in 20%, and neither in 9%. The complication rate was 6.9%, with no major neurological complications. The average length of stay was 5.7 nights. CONCLUSIONS: With ECoG-guided single-stage surgery, we achieved results comparable with other pediatric surgical series and with a low complication rate. An extensive two-stage approach may not be required when there is a lesion on imaging and other information is concordant, even when the MRI abnormality is subtle and unclearly delineated. Frontal foci may present a challenge because of their proximity to "eloquent" nonresectable cortex or critical structures.

Visual Processing in Infants with Tuberous Sclerosis Complex.

Investigators from Harvard University and UCLA have reported that despite evidence of structural abnormalities in the visual pathway of animal models and children with tuberous sclerosis complex (TSC), visual evoked potentials (VEPs) in 12-month old children with TSC compared to an age-matched control group are not significantly altered.

Epilepsy Following Neonatal Seizures Secondary to Hemorrhagic Stroke in Term Neonates.

Intracranial hemorrhage accounts for about 50% of all pediatric stroke. Studies of term infants with intracranial hemorrhage have shown favorable motor and cognitive outcome. The goal of this study was to examine the risk of developing epilepsy in full-term infants with intracranial hemorrhage. A retrospective study was performed of term neonates (greater than or equal to 37 weeks gestation) with intracranial hemorrhage and confirmed seizures. Fifteen patients with intracranial hemorrhage and neonatal seizures were identified. Four patients did not have follow-up information beyond the neonatal period (1 death, 3 lost to follow-up after initial clinic visit). The average follow-up period for the remaining 11 patients was approximately 22 months. Ten out of the 11 patients (91%) who were followed were seizure-free and off antiepileptic medications. One patient required a ventriculoperitoneal shunt and subsequently developed infantile spasms. The authors found that overall outcome was favorable with respect to development of epilepsy.

Cannabidiol in patients with treatment-resistant epilepsy: an open-label interventional trial.

BACKGROUND: Almost a third of patients with epilepsy have a treatment-resistant form, which is associated with severe morbidity and increased mortality. Cannabis-based treatments for epilepsy have generated much interest, but scientific data are scarce. We aimed to establish whether addition of cannabidiol to existing anti-epileptic regimens would be safe, tolerated, and efficacious in children and young adults with treatment-resistant epilepsy. METHODS: In this open-label trial, patients (aged 1-30 years) with severe, intractable, childhood-onset, treatment-resistant epilepsy, who were receiving stable doses of antiepileptic drugs before study entry, were enrolled in an expanded-access programme at 11 epilepsy centres across the USA. Patients were given oral cannabidiol at 2-5 mg/kg per day, up-titrated until intolerance or to a maximum dose of 25 mg/kg or 50 mg/kg per day (dependent on study site). The primary objective was to establish the safety and tolerability of cannabidiol and the primary efficacy endpoint was median percentage change in the mean monthly frequency of motor seizures at 12 weeks. The efficacy analysis was by modified intention to treat. Comparisons of the percentage change in frequency of motor seizures were done with a Mann-Whitney U test. RESULTS: Between Jan 15, 2014, and Jan 15, 2015, 214 patients were enrolled; 162 (76%) patients who had at least 12 weeks of follow-up after the first dose of cannabidiol were included in the safety and tolerability analysis, and 137 (64%) patients were included in the efficacy analysis. In the safety group, 33 (20%) patients had Dravet syndrome and 31 (19%) patients had Lennox-Gastaut syndrome. The remaining patients had intractable epilepsies of different causes and type. Adverse events were reported in 128 (79%) of the 162 patients within the safety group. Adverse events reported in more than 10% of patients were somnolence (n=41 [25%]), decreased appetite (n=31 [19%]), diarrhoea (n=31 [19%]), fatigue (n=21 [13%]), and convulsion (n=18 [11%]). Five (3%) patients discontinued treatment because of an adverse event. Serious adverse events were reported in 48 (30%) patients, including one death-a sudden unexpected death in epilepsy regarded as unrelated to study drug. 20 (12%) patients had severe adverse events possibly related to cannabidiol use, the most common of which was status epilepticus (n=9 [6%]). The median monthly frequency of motor seizures was 30.0 (IQR 11.0-96.0) at baseline and 15.8 (5.6-57.6) over the 12 week treatment period. The median reduction in monthly motor seizures was 36.5% (IQR 0-64.7). INTERPRETATION: Our findings suggest that cannabidiol might reduce seizure frequency and might have an adequate safety profile in children and young adults with highly treatment-resistant epilepsy. Randomised controlled trials are warranted to characterise the safety profile and true efficacy of this compound. FUNDING: GW Pharmaceuticals, Epilepsy Therapy Project of the Epilepsy Foundation, Finding A Cure for Epilepsy and Seizures.

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.

Photosensitivity and CHD2 Variants.

Investigators from multinational institutions hypothesized that disruption of CHD2, which encodes chromodomain helicase DNA-binding protein 2, would be associated with common forms of photosensitive epilepsy or photosensitivity manifesting as a photoparoxysmal response alone.

Interictal attenuation in pediatric electrocorticography can be reliably detected by EEG readers.

Intraoperative electrocorticography (ECoG) helps to demarcate epileptogenic cortex, but a commonly observed feature, interictal attenuation, has received little attention. This may limit its use in the determination of the resection margin. In order to test how reliably EEGers can discern attenuation, we assessed how well EEGers agree with each other and with an objective, quantified measure of attenuation. ECoG segments (n=34) were evaluated for attenuation by two EEGers independently and in consensus, and by an amplitude spectral analysis-based quantitative method. A third EEGer divided the 34 ECoG segments into 3 subgroups-physiologic field present, physiologic field uncertain, and physiologic field absent-based on the clustering patterns of the attenuated electrodes. Inter-rater agreement between two independent EEGers (kappa=0.56) was moderate, and between consensus EEGers and the quantitative method (kappa=0.71) was substantial. These agreements were especially good among the physiologic field present subgroup where the attenuation clearly involved contiguous electrodes, and thus, more likely pathologic (kappa=0.64 for two independent EEGers and kappa=0.78 for consensus EEGers and quantitative method). Our results suggest that interictal attenuation, especially when involving contiguous electrodes, is an ECoG marker that can be consistently and reliably discerned by trained EEGers.

Is the ketogenic diet effective in specific epilepsy syndromes?

Is the ketogenic diet (KD) more effective in certain epilepsy syndromes? The KD has been shown to be effective in treating multiple seizure types and epilepsy syndromes. We review the effectiveness of the KD in Dravet syndrome, epilepsy with myoclonic-atonic seizures, mitochondrial disease, tuberous sclerosis, late infantile and juvenile neuronal ceroid lipofuscinosis, and febrile infection-related epilepsy syndrome. In certain epilepsy syndromes, like epilepsy with myoclonic-atonic seizures, the diet should be considered early in the course of treatment.