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Background and ObjectivesZhu-Tokita-Takenouchi-Kim (ZTTK) syndrome (OMIM 617140) is a recently identified neurodevelopmental disorder caused by heterozygous loss-of-function (LoF) variants inSON. Because the SON protein functions as an RNA-splicing regulator, it has been shown that some clinical features of ZTTK syndrome can be attributed to abnormal RNA splicing. Several neurologic features have been observed in patients with ZTTK syndrome, including seizure/epilepsy and other EEG abnormalities. However, a relationship betweenSONLoF in ZTTK syndrome and hemiplegic migraine remains unknown.MethodsWe identified a patient with a pathogenic variant inSONwho shows typical clinical features of ZTTK syndrome and experienced recurrent episodes of hemiplegic migraine. To define clinical features, brain MRI and EEG during and after episodes of hemiplegic migraine were characterized. To identify molecular mechanisms for this clinical presentation, we investigated the impact of small interfering RNA (siRNA)-mediatedSONknockdown on mRNA expression of theCACNA1A,ATP1A2,SCN1A, andPRRT2genes, known to be associated with hemiplegic migraine, by quantitative RT-PCR. Pre-mRNA splicing ofPRRT2onSONknockdown was further examined by RT-PCR using primers targeting specific exons.ResultsRecurrent episodes of hemiplegic migraine in our patient typically followed modest closed head injuries, and recurrent seizures occurred during the most severe of these episodes. Transient hemispheric cortical interstitial edema and asymmetric EEG slowing were identified during episodes. Our siRNA experiments revealed thatSONknockdown significantly reducesPRRT2mRNA levels in U87MG and SH-SY5Y cell lines, although a reduction inCACNA1A,ATP1A2, andSCN1AmRNA expression was not observed. We further identified thatSONknockdown leads to failure in intron 2 removal fromPRRT2pre-mRNA, resulting in a premature termination codon that blocks the generation of functionally intact full-length PRRT2.DiscussionThis report identifies recurrent hemiplegic migraine as a novel clinical manifestation of ZTTK syndrome, further characterizes this clinical feature, and provides evidence for downregulation ofPRRT2caused bySONLoF as a mechanism causing hemiplegic migraine. Examination of theSONgene may be indicated in individuals with recurrent hemiplegic migraine.

To evaluate the long-term safety and efficacy of add-on cannabidiol (CBD) in patients with seizures associated with tuberous sclerosis complex (TSC) in the open-label extension (OLE) of the randomized, placebo-controlled phase 3 trial GWPCARE6 (NCT02544763). Results of an interim (February 2019 data cut) analysis are reported.Patients who completed the randomized trial enrolled to receive CBD (EpidiolexOf 201 patients who completed the randomized phase, 199 (99%) entered the OLE. Mean age was 13 years (range, 1-57). At the time of analysis, 5% of patients had completed treatment, 20% had withdrawn, and 75% were ongoing. One-year retention rate was 79%. Median treatment time was 267 days (range, 18-910) at a 27 mg/kg/day mean modal dose. Most patients (92%) had an adverse event (AE). Most common AEs were diarrhea (42%), seizure (22%), and decreased appetite (20%). AEs led to permanent discontinuation in 6% of patients. There was one death that was deemed treatment unrelated by the investigator. Elevated liver transaminases occurred in 17 patients (9%) patients; 12 were taking valproate. Median percentage reductions in seizure frequency (12-week windows across 48 weeks) were 54%-68%. Seizure responder rates (≥50%, ≥75%, 100% reduction) were 53%-61%, 29%-45%, and 6%-11% across 12-week windows for 48 weeks. Improvement on the S/CGIC scale was reported by 87% of patients/caregivers at 26 weeks.In patients with TSC, long-term add-on CBD treatment was well tolerated and sustainably reduced seizures through 48 weeks, with most patients/caregivers reporting global improvement.

Objective:The purpose of our study was to assess whether race/ethnicity was associated with seizure remission in pediatric epilepsy.Methods:This was a retrospective population-based cohort study of children who were evaluated for new-onset epilepsy in the clinic, emergency department, and/or hospital by a pediatric neurologist in an integrated health care delivery system. Children were between ages 6 months and 15 years at their initial presentation of epilepsy. The cohort, identified through an electronic database, was assembled over 6 years, with no less than 5 years of follow-up. All children were evaluated for race, ethnicity, insurance type, and socioeconomic background. Patient outcome was determined at the conclusion of the study period and categorized according to their epilepsy control as either drug resistant (pharmacoresistant and intractable) or drug responsive (controlled, probable remission, and terminal remission).Results:In the final cohort of 776 patients, 63% were drug responsive (control or seizure remission). After controlling for confounding socioeconomic and demographic factors, children of Hispanic ethnicity experienced reduced likelihood (hazard) of drug-responsive epilepsy (hazard ratio 0.6, P < .001), and had longer median time to remission (8 years; 95% CI 5.9-9.6 years) compared to white non-Hispanic patients (5.6 years; 95% CI 4.9-6.1 years). Among Hispanic patients, higher health care costs were associated with reduced likelihood of drug responsiveness.Significance:We found that Hispanic ethnicity is associated with a reduced likelihood of achieving seizure control and remission. This study suggests that factors associated with the race/ethnicity of patients contributes to their likelihood of achieving seizure freedom.

Objective To determine the diagnostic yield of a commercial epilepsy gene panel in adults with chronic epilepsy and accompanying intellectual disability, given that genetic evaluation is often overlooked in this group of patients. Methods This is a cross-sectional study analyzing the results of epilepsy gene panels including up to 185 genes in adult epilepsy patients with intellectual disability, according to Diagnostic and Statistical Manual of Mental Disorders, fifth edition. Patients with acquired structural brain abnormalities or known chromosomal abnormalities were excluded. Results From approximately 600 patients seen from January 2017 to June 2018 at a single academic epilepsy center, 64 probands and two affected relatives (32 males, mean age = 31 years ± 10) were selected and clinically tested. Fourteen probands (14/64 = 22%; four males, mean age = 32 years ± 10) were found to have pathogenic or likely pathogenic variants in the following genes: SCN1A, GABRB3, UBE3A, KANSL1, SLC2A1, KCNQ2, SLC6A1, HNRNPU, STX1B, SCN2A, PURA, and CHD2. Six variants arose de novo, and the inheritance was not determined in eight. Nine probands (64%) had severe or profound intellectual disability, and five (35%) had autistic features. Eight patients (57%) had a diagnostic change from presumptive clinical diagnosis prior to genetic testing. Significance We were able to demonstrate that a commercial epilepsy gene panel can be an important resource in clinical practice, identifying the etiology in 22% of adults with epilepsy and intellectual disability. The diagnostic yield is similar to previously reported pediatric cohorts. Larger samples would be required to evaluate the more prevalent genotypes among adult epilepsy patients.

IntroductionComputational analysis of genome or exome sequences may improve inherited disease diagnosis, but is costly and time-consuming.MethodsWe describe the use of iobio, a web-based tool suite for intuitive, real-time genome diagnostic analyses.ResultsWe used iobio to identify the disease-causing variant in a patient with early infantile epileptic encephalopathy with prior nondiagnostic genetic testing.ConclusionsIobio tools can be used by clinicians to rapidly identify disease-causing variants from genomic patient sequencing data.

Innovative therapeutics are transforming care of children with previously untreatable neurological disorders. However, there are challenges in the use of new therapies: the medicine may not be effective in all patients, administration may not be tolerated, and matching therapy choice to patient is complex. Finally, costs are high, which imposes financial burdens on insurance companies, families, and the health-care system. Our objective was to address challenges for clinical implementation of the new therapeutics. We sought to develop a process that would be personalized for patient and disease, encourage appropriate use of a therapeutic agent while mitigating pressure on a clinician to prescribe the therapy in all instances, and assist third-party payers in approving therapeutic use based on safety and efficacy. We report our creation of a Neurology Therapeutics Committee for pediatric patients. We review the committee’s mechanisms, describe its use and report outcomes, and suggest the Neurology Therapeutics Committee’s broader applicability.

Early infantile epileptic encephalopathy (EIEE) is a devastating epilepsy syndrome with onset in the first months of life. Although mutations in more than 50 different genes are known to cause EIEE, current diagnostic yields with gene panel tests or whole-exome sequencing are below 60%. We applied whole-genome analysis (WGA) consisting of whole-genome sequencing and comprehensive variant discovery approaches to a cohort of 14 EIEE subjects for whom prior genetic tests had not yielded a diagnosis. We identified both de novo point and INDEL mutations and de novo structural rearrangements in known EIEE genes, as well as mutations in genes not previously associated with EIEE. The detection of a pathogenic or likely pathogenic mutation in all 14 subjects demonstrates the utility of WGA to reduce the time and costs of clinical diagnosis of EIEE. While exome sequencing may have detected 12 of the 14 causal mutations, 3 of the 12 patients received non-diagnostic exome panel tests prior to genome sequencing. Thus, given the continued decline of sequencing costs, our results support the use of WGA with comprehensive variant discovery as an efficient strategy for the clinical diagnosis of EIEE and other genetic conditions., Pediatric neurology: whole-genome analysis finds mutations causing severe newborn seizures Whole-genome sequencing combined with specialized bioinformatics can diagnose disease mutations in newborns with devastating seizures. Josh Bonkowsky, Gabor Marth, Aaron Quinlan, and colleagues from the University of Utah in Salt Lake City, USA, thoroughly detailed the genomic variation of 14 babies with early infantile epileptic encephalopathy (EIEE). EIEE is a severe pediatric neurodevelopmental disorder causing seizures and early death. In the 14 infants, who had previous testing that did not identify the cause, the research team found the genetic cause for all of the infants. Prior to this work, approaches for EIEE diagnosed only up to 60% of infants. With the cost of DNA sequencing continuing to fall, the authors suggest that whole-genome testing could be a cost-effective approach to diagnosing EIEE and other genetic conditions.

Objective We studied our collective open-label, compassionate use experience in using cannabidiol (CBD) to treat epilepsy in patients with CDKL5 deficiency disorder and Aicardi, Doose, and Dup15q syndromes. Methods We included patients aged 1–30 years with severe childhood-onset epilepsy who received CBD for ≥10 weeks as part of multiple investigator-initiated expanded access or state access programs for a compassionate prospective interventional study: CDKL5 deficiency disorder (n = 20), Aicardi syndrome (n = 19), Dup15q syndrome (n = 8), and Doose syndrome (n = 8). These patients were treated at 11 institutions from January 2014 to December 2016. Results The percent change in median convulsive seizure frequency for all patients taking CBD in the efficacy group decreased from baseline [n = 46] to week 12 (51.4% [n = 35], interquartile range (IQR): 9–85%) and week 48 (59.1% [n = 27], IQR: 14–86%). There was a significant difference between the percent changes in monthly convulsive seizure frequency during baseline and week 12, χ2(2) = 22.9, p = 0.00001, with no difference in seizure percent change between weeks 12 and 48. Of the 55 patients in the safety group, 15 (27%) withdrew from extended observation by week 144: 4 due to adverse effects, 9 due to lack of efficacy, 1 withdrew consent, and 1 was lost to follow-up. Significance This open-label drug trial provides class III evidence for the long-term safety and efficacy of CBD administration in patients with treatment-resistant epilepsy (TRE) associated with CDKL5 deficiency disorder and Aicardi, Dup15q, and Doose syndromes. Adjuvant therapy with CBD showed similar safety and efficacy for these four syndromes as reported in a diverse population of TRE etiologies. This study extended analysis of the prior report from 12 weeks to 48 weeks of efficacy data and suggested that placebo-controlled randomized trials should be conducted to formally assess the safety and efficacy of CBD in these epileptic encephalopathies.

Item does not contain fulltext Developmental and epileptic encephalopathies (DEEs) are severe neurodevelopmental disorders often beginning in infancy or early childhood that are characterized by intractable seizures, abundant epileptiform activity on EEG, and developmental impairment or regression. CACNA1E is highly expressed in the central nervous system and encodes the alpha1-subunit of the voltage-gated CaV2.3 channel, which conducts high voltage-activated R-type calcium currents that initiate synaptic transmission. Using next-generation sequencing techniques, we identified de novo CACNA1E variants in 30 individuals with DEE, characterized by refractory infantile-onset seizures, severe hypotonia, and profound developmental impairment, often with congenital contractures, macrocephaly, hyperkinetic movement disorders, and early death. Most of the 14, partially recurring, variants cluster within the cytoplasmic ends of all four S6 segments, which form the presumed CaV2.3 channel activation gate. Functional analysis of several S6 variants revealed consistent gain-of-function effects comprising facilitated voltage-dependent activation and slowed inactivation. Another variant located in the domain II S4-S5 linker results in facilitated activation and increased current density. Five participants achieved seizure freedom on the anti-epileptic drug topiramate, which blocks R-type calcium channels. We establish pathogenic variants in CACNA1E as a cause of DEEs and suggest facilitated R-type calcium currents as a disease mechanism for human epilepsy and developmental disorders.

BACKGROUND:After licensure of the 7-valent pneumococcal conjugate vaccine (PCV7) in the United States in 2000, the incidence of pediatric pneumococcal meningitis decreased significantly. However, cases continue to occur. It is unknown whether meningitis due to PCV7 and non-PCV7 serotypes causes similar morbidity and mortality.METHODS:We performed a retrospective cohort study of laboratory-confirmed pneumococcal meningitis among Utah children from 1997 to 2010. We reviewed medical records and obtained clinical data during the acute illness and follow-up data on neurologic sequelae.RESULTS:Sixty-eight cases of meningitis were identified. PCV7 serotypes caused 64% of cases before and 25% of cases after licensure of PCV7 (P < .01). The age range was similar before and after PCV7 licensure (P = .5). The overall case fatality rate was 13% and was similar among cases caused by PCV7 and non-PCV7 serotypes (P = .7). Children with PCV7 serotypes were more likely to require mechanical ventilation (68% vs 34%; P < .01). Of all survivors, 63% had neurologic sequelae, and the proportion was similar after infection with PCV7 or non-PCV7 serotypes (P = .1). More than one-half (54%) of all children who developed pneumococcal meningitis in the PCV7 period were eligible for PCV7 and had not been immunized.CONCLUSIONS:Pneumococcal meningitis continues to be associated with high mortality and morbidity; death and neurologic sequelae are common with both PCV7 and non-PCV7 serotype meningitis. The substantial burden of this disease and continued cases among unimmunized children reinforce the need for more effective immunization strategies and continued surveillance in the era of PCV13.

Vici syndrome is a recessively inherited multisystem disorder characterized by callosal agenesis, cataracts, cardiomyopathy, combined immunodeficiency and hypopigmentation. To investigate the molecular basis of Vici syndrome, we carried out exome and Sanger sequence analysis in a cohort of 18 affected individuals. We identified recessive mutations in EPG5 (previously KIAA1632), indicating a causative role in Vici syndrome. EPG5 is the human homolog of the metazoan-specific autophagy gene epg-5, encoding a key autophagy regulator (ectopic P-granules autophagy protein 5) implicated in the formation of autolysosomes. Further studies showed a severe block in autophagosomal clearance in muscle and fibroblasts from individuals with mutant EPG5, resulting in the accumulation of autophagic cargo in autophagosomes. These findings position Vici syndrome as a paradigm of human multisystem disorders associated with defective autophagy and suggest a fundamental role of the autophagy pathway in the immune system and the anatomical and functional formation of organs such as the brain and heart.

Pallister–Killian syndrome (PKS) is a rare, sporadic genetic disorder caused by tetrasomy 12p mosaicism associated with a supernumerary isochromosome. Craniofacial dysmorphism, learning impairment and seizures are considered characteristic. However, little is known of the seizure and epilepsy patterns seen in PKS. To better define the occurrence and nature of epileptic and non-epileptic paroxysmal events in PKS, we describe our experience with 5 patients and compare their features with data from a larger cohort of PKS patients ascertained via a web-based parental questionnaire. Three of the 5 patients have had definite epileptic seizures, and one other has had paroxysmal events as yet not clarified. Four of the 5 have also had either non-epileptic paroxysmal events or episodes of uncertain nature. In those with epilepsy, all have had some period of relatively refractory seizures, all have required more than one antiepileptic drug, but none experienced status epilepticus. Only one of the patients with epilepsy (the oldest) has gone into remission. In two of the four with non-epileptic events, video-electroencephalographic monitoring has been valuable in clarifying the nature of the events. EEG characteristics include a slow dominant frequency as well as generalized and focal epileptiform features. Brain MRI findings can be normal but are variable. These specific findings correspond well to information reported by parents in a larger cohort of 51 individuals with PKS. Better understanding of the nature of epileptic and non-epileptic events in PKS will result from a more detailed analysis of objective data obtained from this larger cohort, and from deeper understanding of the molecular impact of 12p tetrasomy in selected cell lines.

Objectives: Leukodystrophies are diseases of the white matter for which data concerning clinical characteristics, incidence, disease burden, and description of outcomes are sparse. The purpose of our study was to determine the incidence and most common types of inherited leukodystrophies in a population, the mortality and time course of deaths, common neurologic features in patients, and health care costs associated with leukodystrophies. Methods: We conducted a retrospective, hospital- and clinic-based surveillance of inherited leukodystrophies among children younger than 18 years presenting to a regional children9s hospital. We enrolled children evaluated from January 1, 1999, through December 31, 2007; clinical information was obtained from medical records. We calculated incidence based on state birth rates. Results: A total of 122 children with an inherited leukodystrophy were identified; 542 patients were excluded. A total of 49% had epilepsy, 43% required a gastrostomy tube, and 32% had a history of developmental regression. Mortality was 34%; average age at death was 8.2 years. No final diagnosis was reported in 51% of patients. The most common diagnoses were metachromatic leukodystrophy (8.2%), Pelizaeus-Merzbacher disease (7.4%), mitochondrial diseases (4.9%), and adrenoleukodystrophy (4.1%). Endocrine abnormalities and hypoplastic cerebellum were noted in significant portions of patients (15% and 14%). Average yearly per-patient medical costs were $22,579. Population incidence was 1 in 7,663 live births. Conclusions: Inherited leukodystrophies are associated with substantial morbidity and mortality in children. Overall population incidence is higher than generally appreciated (1 in 7,663 live births). Most leukodystrophies remain undiagnosed, but a logical algorithm based on prevalence could aid testing.

Summary 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.

Summary: Purpose: To use available evidence and expert consensus to develop performance indicators for the evaluation and management of pediatric epilepsy. Methods: We used a three-step process to develop the performance indicators. First, research findings were compiled into evidence tables focusing on different clinical issues. Second, an advisory panel of clinicians, educational and public health experts, and families of children with epilepsy reviewed the evidence. The advisory group used the evidence to draft a preliminary set of performance indicators for pediatric epilepsy management. Third, 13 internationally recognized experts in pediatric neurology or epilepsy rated the value of these indicators on a 5-point scale [1 (essential) to 5 (not necessary)] in a two-round Delphi process. Positive consensus was reached if ≥80% of experts gave an indicator a “1” rating and negative consensus if >80% gave an indicator a “5” rating. Indicators that achieved positive consensus during either round of the Delphi process constituted the final set of indicators. Results: Of the 68 draft performance indicators, the expert panel members achieved positive consensus on 30 performance indicators: eight indicators related to diagnostic strategies and seizure classification, nine related to antiepileptic drug use, six related to cognitive and behavioral issues, six related to quality of life, and three related to specialty referrals. Conclusions: We identified 30 potential indicators for evaluating the care provided to pediatric patients with epilepsy. The next step is to examine the relation of these performance indicators to clinical outcomes and health care utilization among pediatric patients with epilepsy.

Management of pediatric epilepsy requires complex coordination of care. We hypothesized that an improved seizure management care plan would reduce health care utilization and improve outcomes. The authors conducted a cohort study with historical controls of 120 epilepsy patients before and after implementation of a “Seizure Action Plan.” The authors evaluated for differences in health care utilization including emergency department visits, hospitalizations, clinic visits, telephone calls, and the percentage of emergency department visits that resulted in hospitalization in patients who did or did not have a Seizure Action Plan. The authors found that there was no decrease in these measures of health care utilization, and in fact the number of follow-up clinic visits was increased in the group with Seizure Action Plans (4.2 vs 3.3, P = .006). However, the study was underpowered to detect smaller differences. This study suggests that pediatric epilepsy quality improvement measures may require alternative approaches to reduce health care utilization and improve outcomes.

Objective To compare intranasal midazolam, using a Mucosal Atomization Device (IN-MMAD), with rectal diazepam (RD) for the home treatment of seizures in children with epilepsy. Design Prospective randomized study. Setting Patients' homes and a freestanding children's hospital that serves as a referral center for 5 states. Patients A total of 358 pediatric patients who visited a pediatric neurology clinic from July 2006 through September 2008 and were prescribed a home rescue medication for their next seizure. Intervention Caretakers were randomized to use either 0.2 mg/kg of IN-MMAD (maximum, 10 mg) or 0.3 to 0.5 mg/kg of RD (maximum, 20 mg) at home for their child's next seizure if it lasted more than 5 minutes. Outcome Measures The primary outcome measure was total seizure time after medication administration. Our secondary outcome measures were total seizure time, time to medication administration, respiratory complications, emergency medical service support, emergency department visits, hospitalizations, and caretakers' ease of administration and satisfaction with the medication. Results A total of 92 caretakers gave the study medication during a child's seizure (50 IN-MMAD, 42 RD). The median time from medication administration to seizure cessation for IN-MMAD was 1.3 minutes less than for RD (95% confidence interval, 0.0-3.5 minutes; P = .09). The median time to medication administration was 5.0 minutes for each group. No differences in complications were found between treatment groups. Caretakers were more satisfied with IN-MMAD and report that it was easier to give than RD. Conclusions There was no detectable difference in efficacy between IN-MMAD and RD as a rescue medication for terminating seizures at home in pediatric patients with epilepsy. Ease of administration and overall satisfaction was higher with IN-MMAD compared with RD. Trial Registration clinicaltrials.gov Identifier:NCT00326612

A follow-up study of a large Utah family with significant linkage to chromosome 2q24 led us to identify a new febrile seizure (FS) gene, SCN9A encoding Nav1.7. In 21 affected members, we uncovered a potential mutation in a highly conserved amino acid, p.N641Y, in the large cytoplasmic loop between transmembrane domains I and II that was absent from 586 ethnically matched population control chromosomes. To establish a functional role for this mutation in seizure susceptibility, we introduced the orthologous mutation into the murine Scn9a ortholog using targeted homologous recombination. Compared to wild-type mice, homozygous Scn9aN641Y/N641Y knockin mice exhibit significantly reduced thresholds to electrically induced clonic and tonic-clonic seizures, and increased corneal kindling acquisition rates. Together, these data strongly support the SCN9A p.N641Y mutation as disease-causing in this family. To confirm the role of SCN9A in FS, we analyzed a collection of 92 unrelated FS patients and identified additional highly conserved Nav1.7 missense variants in 5% of the patients. After one of these children with FS later developed Dravet syndrome (severe myoclonic epilepsy of infancy), we sequenced the SCN1A gene, a gene known to be associated with Dravet syndrome, and identified a heterozygous frameshift mutation. Subsequent analysis of 109 Dravet syndrome patients yielded nine Nav1.7 missense variants (8% of the patients), all in highly conserved amino acids. Six of these Dravet syndrome patients with SCN9A missense variants also harbored either missense or splice site SCN1A mutations and three had no SCN1A mutations. This study provides evidence for a role of SCN9A in human epilepsies, both as a cause of FS and as a partner with SCN1A mutations.

To use available evidence and expert consensus to develop performance indicators for the evaluation and management of pediatric epilepsy.We used a three-step process to develop the performance indicators. First, research findings were compiled into evidence tables focusing on different clinical issues. Second, an advisory panel of clinicians, educational and public health experts, and families of children with epilepsy reviewed the evidence. The advisory group used the evidence to draft a preliminary set of performance indicators for pediatric epilepsy management. Third, 13 internationally recognized experts in pediatric neurology or epilepsy rated the value of these indicators on a 5-point scale [1 (essential) to 5 (not necessary)] in a two-round Delphi process. Positive consensus was reached ifor=80% of experts gave an indicator a "1" rating and negative consensus if80% gave an indicator a "5" rating. Indicators that achieved positive consensus during either round of the Delphi process constituted the final set of indicators.Of the 68 draft performance indicators, the expert panel members achieved positive consensus on 30 performance indicators: eight indicators related to diagnostic strategies and seizure classification, nine related to antiepileptic drug use, six related to cognitive and behavioral issues, six related to quality of life, and three related to specialty referrals.We identified 30 potential indicators for evaluating the care provided to pediatric patients with epilepsy. The next step is to examine the relation of these performance indicators to clinical outcomes and health care utilization among pediatric patients with epilepsy.