Protective effect of the ketogenic diet in Scn1a mutant mice

Categorizing Monogenic Epilepsies by Genetic Mechanisms May Predict Efficacy of the Ketogenic Diet

BACKGROUND

The ketogenic diet (KD) is an effective treatment for epilepsy. In recent years, studies have shown favorable efficacy of KD in epilepsy from genetic disorders. In this study, we propose an approach to KD in monogenic epilepsy: we evaluate the utility of categorizing genetic variants based on rational associations with the known mechanisms of KD.

METHODS

Patients with monogenic epilepsy treated with KD were reviewed. The genetic etiologies were categorized into five groups: (1) conditions causing cellular energy impairment, (2) GABA-pathies, (3) mToR-pathies, (4) ion channelopathies, and (5) no known mechanisms associated with KD mechanisms. Treatment response was defined as a median reduction in seizure frequency of greater than 50%.

RESULTS

Of 35 patients, 24 (69%) were responders at three months. Based on categories, Group 1 had the highest response rate with seven of seven (100%), followed by Group 2, six of seven (86%), and Group 3, two of three (67%). Patients in Groups 4 and 5 had poorer responses with three of seven (43%) and four of 11 (36%) response rates, respectively (P < 0.01). Median percentage of seizure reduction showed Group 1 with the highest reduction of 97.5%, Group 2 at 94%, and Groups 3, 4, and 5 at 62.5%, 30%, and 40%, respectively (P = 0.036).

CONCLUSION

Our findings show a favorable response to KD in patients with monogenic epilepsy (69% at three months) with the highest response in patients with conditions involving cellular energy impairment and GABA-pathies. The KD, therefore, should be considered early in patients with monogenic epilepsy, especially those involving genes associated with cellular energy impairment or GABA-pathies.

Diet and Nutrients in Rare Neurological Disorders: Biological, Biochemical, and Pathophysiological Evidence

Background/Objectives: Rare diseases are a wide and heterogeneous group of multisystem life-threatening or chronically debilitating clinical conditions with reduced life expectancy and a relevant mortality rate in childhood. Some of these disorders have typical neurological symptoms, presenting from birth to adulthood. Dietary patterns and nutritional compounds play key roles in the onset and progression of neurological disorders, and the impact of alimentary needs must be enlightened especially in rare neurological diseases. This work aims to collect the in vitro, in vivo, and clinical evidence on the effects of diet and of nutrient intake on some rare neurological disorders, including some genetic diseases, and rare brain tumors. Herein, those aspects are critically linked to the genetic, biological, biochemical, and pathophysiological hallmarks typical of each disorder. Methods: By searching the major web-based databases (PubMed, Web of Science Core Collection, DynaMed, and Clinicaltrials.gov), we try to sum up and improve our understanding of the emerging role of nutrition as both first-line therapy and risk factors in rare neurological diseases. Results: In line with the increasing number of consensus opinions suggesting that nutrients should receive the same attention as pharmacological treatments, the results of this work pointed out that a standard dietary recommendation in a specific rare disease is often limited by the heterogeneity of occurrent genetic mutations and by the variability of pathophysiological manifestation. Conclusions: In conclusion, we hope that the knowledge gaps identified here may inspire further research for a better evaluation of molecular mechanisms and long-term effects.

Effects of a Ketogenic Diet on the Assessment of Biochemical and Clinical Parameters in Duchenne Muscular Dystrophy: A Preclinical Investigation

Duchenne muscular dystrophy (DMD) is an X-linked recessive disorder characterized by progressive skeletal muscle degeneration and systemic effects, including the central nervous system (CNS). This study aimed to assess the impact of a 14-day ketogenic diet (DCet) on biochemical and clinical parameters in a DMD mouse model. Young adult mice (50 days old) were fed DCet, while control groups received a standard diet. On the 14th day, memory and behavior tests were conducted, followed by biochemical evaluations of oxidative stress, inflammatory biomarkers, body weight, feed intake, and brain-derived neurotrophic factor (BDNF) levels. mdx + DCet mice showed reduced mass (0.2 g ± 2.49) and improved memory retention (p < 0.05) compared to controls. Oxidative damage in muscle tissue and CNS decreased, along with a significant cytokine level reduction (p <0.05). The protocol led to an increase in hippocampal BDNF and mitochondrial respiratory complex activity in muscle tissue and the central nervous system (CNS), while also decreasing creatine kinase activity only in the striatum. Overall, a 14-day DCet showed protective effects by improving spatial learning and memory through reductions in oxidative stress and immune response, as well as increases in BDNF levels, consistent with our study's findings.

Targeted Molecular Strategies for Genetic Neurodevelopmental Disorders: Emerging Lessons from Dravet Syndrome

Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the SCN1A gene encoding the voltage-gated sodium channel α subunit Nav1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for SCN1A-related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional SCN1A or by activating Nav1.1. These include antisense nucleotides directed against the nonproductive transcript of SCN1A with the poison exon 20N and against an inhibitory noncoding antisense RNA of SCN1A. Gene therapy approaches such as adeno-associated virus-based upregulation of SCN1A using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.

Functional analysis of a novel de novo SCN2A variant in a patient with seizures refractory to oxcarbazepine

Objective

We admitted a female patient with infantile onset epilepsy (<3-month-old). The use of oxcarbazepine exacerbated epileptic seizures in the patient. In the present study, we aimed to identify the genetic basis of the infantile onset epilepsy in the patient, and determine the correlations among genotype, phenotype, and clinical drug response.

Methods

We described the clinical characteristics of an infant with refractory epilepsy. Whole exome sequencing (WES) was used to screen for the pathogenic variant. Whole-cell patch-clamp was performed to determine functional outcomes of the variant.

Results

WES identified a novel de novo SCN2A variant (c.468 G > C, p.K156N) in the patient. In comparison with wildtype, electrophysiology revealed that SCN2A-K156N variant in transfected cells demonstrated reduced sodium current density, delayed activation and accelerated inactivation process of Na⁺ channel, all of which suggested a loss-of-function (LOF) of Na_v1.2 channel.

Conclusion

We showed the importance of functional analysis for a SCN2A variant with unknown significance to determine pathogenicity, drug reactions, and genotype-phenotype correlations. For patients suffering from early infantile epilepsies, the use of oxcarbazepine in some SCN2A-related epilepsies requires vigilance to assess the possibility of epilepsy worsening.

USE OF KETOGENIC DIET THERAPY IN EPILEPSY WITH MITOCHONDRIAL DYSFUNCTION: A SYSTEMATIC AND CRITICAL REVIEW

With the development of molecular techniques over time more than %60 of epilepsy has associated with mitochondrial (mt) dysfunction. Ketogenic diet (KD) has been used in the treatment of epilepsy since the 1920s. Aim. To evaluate the evidence behind KD in mt dysfunction in epilepsy. Methods. Databases PubMed, Google Scholar and MEDLINE were searched in an umbrella approach to 12 March 2021 in English. To identify relevant studies specific search strategies were devised for the following topics: (1) mitochondrial dysfunction (2) epilepsy (3) KD treatment. Results. From 1794 papers, 36 articles were included in analysis: 16 (%44.44) preclinical studies, 11 (%30.55) case reports, 9 (%25) clinical studies. In all the preclinic studies, KD regulated the number of mt profiles, transcripts of metabolic enzymes and encoding mt proteins, protected the mice against to seizures and had an anticonvulsant mechanism. Case reports and clinical trials have reported patients with good results in seizure control and mt functions, although not all of them give good results as well as preclinical. Conclusion. Healthcare institutions, researchers, neurologists, health promotion organizations, and dietitians should consider these results to improve KD programs and disease outcomes for mt dysfunction in epilepsy.

A ketogenic diet protects DBA/1 and Scn1aR1407X/+ mice against seizure-induced respiratory arrest independent of ketosis

Patients with uncontrolled epilepsy have a high risk of sudden unexpected death in epilepsy (SUDEP). Seizure-induced respiratory arrest (S-IRA) is thought to be the determining cause of death in many cases of SUDEP. The goal of the present study was to use Scn1aR1407X/+ (Dravet Syndrome, DS) and DBA/1 mice to determine: (1) the effect of a ketogenic diet (KD) on S-IRA and (2) the relationship between serum ketones and the protective effect of a KD. Ketogenic diet treatment significantly decreased spontaneous seizure-induced mortality in DS mice compared to control (8% vs 39%, p = 0.0021). This protective effect was not abolished when ketosis was prevented by supplementing the KD with glucose (10% mortality, p = 0.0007). In DBA/1 mice, the latency to onset of S-IRA due to audiogenic seizures was delayed from 7.6 to 20.8 seconds by a KD on treatment day (TD) 7 compared to control (p < 0.0001), an effect that was reversed on TD14 when mice were crossed over to a control diet on TD7. β-Hydroxybutyrate (BHB) levels were significantly decreased in DBA/1 mice on a KD supplemented with glucose (p = 0.0038), but the protective effect was maintained. Our findings show that a KD decreases SUDEP in DS mice and increases the latency to audiogenic S-IRA in DBA/1 mice. In both mouse models, a KD was protective against S-IRA. This effect may be due in part to specific dietary components rather than generation of ketone bodies.

Alterations in the gut microbiota contribute to cognitive impairment induced by the ketogenic diet and hypoxia

Many genetic and environmental factors increase susceptibility to cognitive impairment (CI), and the gut microbiome is increasingly implicated. However, the identity of gut microbes associated with CI risk, their effects on CI, and their mechanisms remain unclear. Here, we show that a carbohydrate-restricted (ketogenic) diet potentiates CI induced by intermittent hypoxia in mice and alters the gut microbiota. Depleting the microbiome reduces CI, whereas transplantation of the risk-associated microbiome or monocolonization with Bilophila wadsworthia confers CI in mice fed a standard diet. B. wadsworthia and the risk-associated microbiome disrupt hippocampal synaptic plasticity, neurogenesis, and gene expression. The CI is associated with microbiome-dependent increases in intestinal interferon-gamma (IFNg)-producing Th1 cells. Inhibiting Th1 cell development abrogates the adverse effects of both B. wadsworthia and environmental risk factors on CI. Together, these findings identify select gut bacteria that contribute to environmental risk for CI in mice by promoting inflammation and hippocampal dysfunction.

Ketogenic diets and the nervous system: a scoping review of neurological outcomes from nutritional ketosis in animal studies

OBJECTIVES

Ketogenic diets have reported efficacy for neurological dysfunctions; however, there are limited published human clinical trials elucidating the mechanisms by which nutritional ketosis produces therapeutic effects. The purpose of this present study was to investigate animal models that report variations in nervous system function by changing from a standard animal diet to a ketogenic diet, synthesise these into broad themes, and compare these with mechanisms reported as targets in pain neuroscience to inform human chronic pain trials.

METHODS

An electronic search of seven databases was conducted in July 2020. Two independent reviewers screened studies for eligibility, and descriptive outcomes relating to nervous system function were extracted for a thematic analysis, then synthesised into broad themes.

RESULTS

In total, 170 studies from eighteen different disease models were identified and grouped into fourteen broad themes: alterations in cellular energetics and metabolism, biochemical, cortical excitability, epigenetic regulation, mitochondrial function, neuroinflammation, neuroplasticity, neuroprotection, neurotransmitter function, nociception, redox balance, signalling pathways, synaptic transmission and vascular supply.

DISCUSSION

The mechanisms presented centred around the reduction of inflammation and oxidative stress as well as a reduction in nervous system excitability. Given the multiple potential mechanisms presented, it is likely that many of these are involved synergistically and undergo adaptive processes within the human body, and controlled animal models that limit the investigation to a particular pathway in isolation may reach differing conclusions. Attention is required when translating this information to human chronic pain populations owing to the limitations outlined from the animal research.

Ketogenic Diets Induced Glucose Intolerance and Lipid Accumulation in Mice with Alterations in Gut Microbiota and Metabolites

The ketogenic diet (KD), which can induce changes in gut microbiota, has shown benefits for epilepsy and several neurodegenerative diseases. However, the effects of a KD on glucose and lipid metabolism remain inconclusive. Using two formulas of ketogenic diets (KDR with 89.5% fat and KDH with 91.3% fat), which are commonly used in mouse trials, we found that KDR but not KDH induced insulin resistance and damaged glucose homeostasis, while KDH induced more fat accumulation in mice. Further study showed that KD impacted glucose metabolism, which was related to the sources of fat, while both the sources and proportions of fat affected lipid metabolism. And the KD widely used in human studies still induced insulin resistance and fat accumulation in mice. Moreover, KDs changed the gut microbiota and metabolites in mice, and the sources and proportions of fat in the diets respectively changed the abundance of specific bacteria and metabolites which were correlated with parameters related to glucose intolerance and lipid accumulation. Overall, our study demonstrated that the metabolic disorders induced by KDs are closely related to the source and proportion of fat in the diet, which may be associated with the changes of the gut microbiota and metabolites.IMPORTANCE The ketogenic diet with extremely high fat and very low carbohydrate levels is very popular in society today. Although it has beneficial effects on epilepsy and neurodegenerative diseases, how ketogenic diets impact host glucose and lipid metabolism and gut microbiota still needs further investigation. Here, we surveyed the effects of two ketogenic diets which are commonly used in mouse trials on metabolic phenotypes, gut microbiota, and metabolites in mice. We found that both ketogenic diets impaired glucose and lipid metabolism in mice, and this may be due to the sources and proportions of fat in the diets. This work highlights the potential risk of glucose and lipid metabolism disorders and the importance of evaluating the sources and proportions of fat in the diets, when using ketogenic diets for weight loss and the treatment of diseases.

Sodium channelopathies of skeletal muscle and brain

Voltage-gated sodium channels initiate action potentials in nerve, skeletal muscle, and other electrically excitable cells. Mutations in them cause a wide range of diseases. These channelopathy mutations affect every aspect of sodium channel function, including voltage sensing, voltage-dependent activation, ion conductance, fast and slow inactivation, and both biosynthesis and assembly. Mutations that cause different forms of periodic paralysis in skeletal muscle were discovered first and have provided a template for understanding structure, function, and pathophysiology at the molecular level. More recent work has revealed multiple sodium channelopathies in the brain. Here we review the well-characterized genetics and pathophysiology of the periodic paralyses of skeletal muscle and then use this information as a foundation for advancing our understanding of mutations in the structurally homologous α-subunits of brain sodium channels that cause epilepsy, migraine, autism, and related comorbidities. We include studies based on molecular and structural biology, cell biology and physiology, pharmacology, and mouse genetics. Our review reveals unexpected connections among these different types of sodium channelopathies.

Atypical myelinogenesis and reduced axon caliber in the Scn1a variant model of Dravet syndrome: An electron microscopy pilot study of the developing and mature mouse corpus callosum

Dravet Syndrome (DS) is a genetic neurodevelopmental disease. Recurrent severe seizures begin in infancy and co-morbidities follow, including developmental delay, cognitive and behavioral dysfunction. A majority of DS patients have an SCN1A heterozygous gene mutation. This mutation causes a loss-of-function in inhibitory neurons, initiating seizure onset. We have investigated whether the sodium channelopathy may result in structural changes in the DS model independent of seizures. Morphometric analyses of axons within the corpus callosum were completed at P16 and P50 in Scn1a heterozygote KO male mice and their age-matched wild-type littermates. Trainable machine learning algorithms were used to examine electron microscopy images of ~400 myelinated axons per animal, per genotype, including myelinated axon cross-section area, frequency distribution and g-ratios. Pilot data for Scn1a heterozygote KO mice demonstrate the average axon caliber was reduced in developing and adult mice. Qualitative analysis also shows micro-features marking altered myelination at P16 in the DS model, with myelin out-folding and myelin debris within phagocytic cells. The data has indicated, in the absence of behavioral seizures, factors that governed a shift toward small calibre axons at P16 have persisted in adult Scn1a heterozygote KO corpus callosum. The pilot study provides a basis for future meta-analysis that will enable robust estimates of the effects of the sodium channelopathy on axon architecture. We propose that early therapeutic strategies in DS could help minimize the effect of sodium channelopathies, beyond the impact of overt seizures, and therefore achieve better long-term treatment outcomes.

Diet in the Treatment of Epilepsy: What We Know So Far

Epilepsy is a chronic and debilitating neurological disorder, with a worldwide prevalence of 0.5–1% and a lifetime incidence of 1–3%. An estimated 30% of epileptic patients continue to experience seizures throughout life, despite adequate drug therapy or surgery, with a major impact on society and global health. In recent decades, dietary regimens have been used effectively in the treatment of drug-resistant epilepsy, following the path of a non-pharmacological approach. The ketogenic diet and its variants (e.g., the modified Atkins diet) have an established role in contrasting epileptogenesis through the production of a series of cascading events induced by physiological ketosis. Other dietary regimens, such as caloric restriction and a gluten free diet, can also exert beneficial effects on neuroprotection and, therefore, on refractory epilepsy. The purpose of this review was to analyze the evidence from the literature about the possible efficacy of different dietary regimens on epilepsy, focusing on the underlying pathophysiological mechanisms, safety, and tolerability both in pediatric and adult population. We believe that a better knowledge of the cellular and molecular biochemical processes behind the anticonvulsant effects of alimentary therapies may lead to the development of personalized dietary intervention protocols.

Chrononutrition in the management of diabetes

Circadian rhythms are 24-h cycles regulated by endogeneous molecular oscillators called the circadian clock. The effects of diet on circadian rhythmicity clearly involves a relationship between factors such as meal timings and nutrients, known as chrononutrition. Chrononutrition is influenced by an individual's "chronotype", whereby "evening chronotypes" or also termed "later chronotype" who are biologically driven to consume foods later in the day. Research in this area has suggested that time of day is indicative of having an influence on the postprandial glucose response to a meal, therefore having a major effect on type 2 diabetes. Cross-sectional and experimental studies have shown the benefits of consuming meals early in the day than in the evening on postprandial glycaemia. Modifying the macronutrient composition of night meals, by increasing protein and fat content, has shown to be a simple strategy to improve postprandial glycaemia. Low glycaemic index (GI) foods eaten in the morning improves glycaemic response to a greater effect than when consumed at night. Timing of fat and protein (including amino acids) co-ingested with carbohydrate foods, such as bread and rice, can reduce glycaemic response. The order of food presentation also has considerable potential in reducing postprandial blood glucose (consuming vegetables first, followed by meat and then lastly rice). These practical recommendations could be considered as strategies to improve glycaemic control, rather than focusing on the nutritional value of a meal alone, to optimize dietary patterns of diabetics. It is necessary to further elucidate this fascinating area of research to understand the circadian system and its implications on nutrition that may ultimately reduce the burden of type 2 diabetes.

Genetic and phenotypic characteristics of SCN1A-related epilepsy in Chinese children

SCN1A gene mutations are associated with epilepsy and neurodevelopmental disorders. This study aimed to explore the genotype and phenotype spectrum of SCN1A gene related epilepsy. Epileptic patients who were treated in the Children's Hospital of Chongqing Medical University from January 2015 to July 2018 and identified as having SCN1A mutations by targeted next-generation sequencing were included. Clinical manifestations of all patients were analyzed retrospectively. A total of 24 patients with SCN1A mutations were identified. The age of epilepsy onset ranged from 2 months to 2 years and 9 months. Multiple seizure types were observed. A total of 13 (54.2%) patients had three or more types of seizures. Overall, 16 (66.7%) patients had status epilepticus, 11 (45.8%) patients had fever sensitivity, and nine (37.5%) patients had seizures after vaccination. Moreover, 15 (62.5%) patients showed varying degrees of cognitive and motor development retardation. In addition, two patients had mutations inherited from one of their parents and 22 (91.7%) patients had de novo mutations. The following SCN1A mutation types were identified: missense (16 patients, 66.7%), nonsense (four patients, 16.7%), splice site (one patient), frameshift (one patient), and large deletions (two patients). Overall, 23 of the patients received antiepileptic therapy, of which eight (33.3%) patients had no decrease in seizures and 11 (45.8%) patients had more than 50% decrease in seizure frequency. Three patients had poor response to antiepileptic drug therapy before attempting ketogenic diet, after which seizure frequency decreased by 50%. A total of 10 (41.7%) patients had used sodium channel blockers before accurate diagnosis, all of whom showed ineffective or even aggravated seizure response. SCN1A mutations are associated with a spectrum of seizure-related disorders, ranging from a relatively mild form of febrile seizures to a more severe epileptic encephalopathy known as Dravet syndrome. Early diagnosis of SCN1A mutation-associated epilepsy can aid in appropriate choice of antiepileptic drugs for treatment and reducing adverse sequelae.

Mutations in the Scn8a DIIS4 voltage sensor reveal new distinctions among hypomorphic and null Nav 1.6 sodium channels

Mutations in the voltage-gated sodium channel gene SCN8A cause a broad range of human diseases, including epilepsy, intellectual disability, and ataxia. Here we describe three mouse lines on the C57BL/6J background with novel, overlapping mutations in the Scn8a DIIS4 voltage sensor: an in-frame 9 bp deletion (Δ9), an in-frame 3 bp insertion (∇3) and a 35 bp deletion that results in a frameshift and the generation of a null allele (Δ35). Scn8a ^Δ9/+ and Scn8a ^∇3/+ heterozygous mutants display subtle motor deficits, reduced acoustic startle response, and are resistant to induced seizures, suggesting that these mutations reduce activity of the Scn8a channel protein, Na_v 1.6. Heterozygous Scn8a ^Δ35/+ mutants show no alterations in motor function or acoustic startle response, but are resistant to induced seizures. Homozygous mutants from each line exhibit premature lethality and severe motor impairments, ranging from uncoordinated gait with tremor (Δ9 and ∇3) to loss of hindlimb control (Δ35). Scn8a ^Δ9/Δ9 and Scn8a ^∇3/∇3 homozygous mutants also exhibit impaired nerve conduction velocity, while normal nerve conduction was observed in Scn8a ^Δ35/Δ35 homozygous mice. Our results suggest that hypomorphic mutations that reduce Na_v 1.6 activity will likely result in different clinical phenotypes compared to null alleles. These three mouse lines represent a valuable opportunity to examine the phenotypic impacts of hypomorphic and null Scn8a mutations without the confound of strain-specific differences.

The Effects of Ketogenic Diet Treatment in Kcna1-Null Mouse, a Model of Sudden Unexpected Death in Epilepsy

Sudden unexpected death in epilepsy (SUDEP) is a leading cause of abrupt death in patient with epilepsy. It represents 5-30% of all rapid deaths in individuals with epilepsy. Ketogenic diet (KD) has been used in clinic for treatment of epilepsy for many decades. However, the cellular and molecular mechanisms underlying the SUDEP and the relationship between KD and SUDEP remain uncertain. Kcna1-null (Kcna1^-/-) mouse, an animal model of SUDEP, is frequently used to study mechanisms underlying SUDEP. The current mini-review focus on risk factors for SUDEP and their relationship with KD treatment in Kcna1^-/- mice. Emerging data suggest that factors including seizure frequency, longevity, rest, age, and gender both in Kcna1^-/- mice and KD treated Kcna1^-/-mice are involved in SUDEP. This provides valuable prediction for clinical application of KD for treatment of SUDEP.

Time of Day and a Ketogenic Diet Influence Susceptibility to SUDEP in Scn1a R1407X/+ Mice

Sudden unexpected death in epilepsy (SUDEP) is a major cause of mortality in patients with drug-resistant epilepsy. Most SUDEP cases occur in bed at night and are preceded by a generalized tonic-clonic seizure (GTCS). Dravet syndrome (DS) is a severe childhood-onset epilepsy commonly caused by mutations in the SCN1A gene. Affected individuals suffer from refractory seizures and an increased risk of SUDEP. Here, we demonstrate that mice with the Scn1a^R1407X/+ loss-of-function mutation (DS) experience more spontaneous seizures and SUDEP during the early night. We also evaluate effects of long-term ketogenic diet (KD) treatment on mortality and seizure frequency. DS mice showed high premature mortality (44% survival by P60) that was associated with increased spontaneous GTCSs 1–2 days prior to SUDEP. KD treated mice had a significant reduction in mortality (86% survival by P60) compared to mice fed a control diet. Interestingly, increased survival was not associated with a decrease in seizure frequency. Further studies are needed to determine how KD confers protection from SUDEP. Moreover, our findings implicate time of day as a factor influencing the occurrence of seizures and SUDEP. DS mice, though nocturnal, are more likely to have SUDEP at night, suggesting that the increased incidence of SUDEP at night in may not be solely due to sleep.

Efficacy of the ketogenic diet in Chinese children with Dravet syndrome: A focus on neuropsychological development

OBJECTIVES

In this retrospective study, we evaluated the efficacy of the ketogenic diet (KD) treatment in Chinese children with Dravet syndrome (DS) as well as its effect on neuropsychological development.

METHODS

Twenty-six children (14 male) living with DS and being treated with KD at our department between July 2014 and December 2017 were enrolled in the study. The efficacy of KD was measured by seizure frequency before and after the diet. Additionally, children's neuropsychological development, as evaluated by the Gesell developmental schedule, was compared between the KD and a non-KD group.

RESULTS

After 3, 6, 12, 18, 24, and 30 months, 92.3%, 84.6%, 46.2%, 30.8%, 19.2%, and 19.2% remained on the KD, while 38.4%, 34.6%, 38.4%, 23.0%, 15.4%, and 15.4% showed >50% reduction in seizure. The development age (DA) subscores of 12 children, as measured by the Gesell developmental schedule, increased after commencement of KD. However, children's development quotient (DQ) subscores (age-adjusted) decreased after KD. In the non-KD group (40 participants), an increase of DA subscores and decrease of DQ subscores were also observed. Results found no difference in changes of DQ subscores over time between the two groups. The DQ subscores after the diet in the KD group (20 participants) did not differ significantly when compared to the DQ subscores at same age in the non-KD group (20 patients) (t-test).

CONCLUSIONS

The DA subscores of 12 children in KD group increased after KD; when compared with that of the non-KD group, no significant difference was observed in respect to the changes of DQ subscore over time. Effects on cognitive and other neuropsychological development outcomes of KD for children living with DS require further study.

The Gut Microbiota Mediates the Anti-Seizure Effects of the Ketogenic Diet

The ketogenic diet (KD) is used to treat refractory epilepsy, but the mechanisms underlying its neuroprotective effects remain unclear. Here, we show that the gut microbiota is altered by the KD and required for protection against acute electrically induced seizures and spontaneous tonic-clonic seizures in two mouse models. Mice treated with antibiotics or reared germ free are resistant to KD-mediated seizure protection. Enrichment of, and gnotobiotic co-colonization with, KD-associated Akkermansia and Parabacteroides restores seizure protection. Moreover, transplantation of the KD gut microbiota and treatment with Akkermansia and Parabacteroides each confer seizure protection to mice fed a control diet. Alterations in colonic lumenal, serum, and hippocampal metabolomic profiles correlate with seizure protection, including reductions in systemic gamma-glutamylated amino acids and elevated hippocampal GABA/glutamate levels. Bacterial cross-feeding decreases gamma-glutamyltranspeptidase activity, and inhibiting gamma-glutamylation promotes seizure protection in vivo. Overall, this study reveals that the gut microbiota modulates host metabolism and seizure susceptibility in mice.

Synergistic protection against acute flurothyl-induced seizures by adjuvant treatment of the ketogenic diet with the type 2 diabetes drug pioglitazone

OBJECTIVE

We have previously found that the transcription factor peroxisome proliferator-activated receptor γ (PPARγ) contributes to the mechanism of action of the ketogenic diet (KD), an established treatment for pediatric refractory epilepsy. We have found that the KD increases brain PPARγ and that inhibition or genetic loss of PPARγ prevents the antiseizure effects of the KD on (1) acutely induced seizures in nonepileptic mice and (2) spontaneous recurrent seizures in epileptic mice. Here, we tested the hypothesis that adjuvant treatment of KD-treated mice with a PPARγ agonist, pioglitazone, would result in an additive effect.

METHODS

Acute seizures were induced in three groups of C57Bl/6 mice by inhalation exposure to flurothyl gas. In Group 1, mice were weaned onto either a standard diet or KD comprised of a fat:carbohydrate/protein ratio of either 6:1, 3:1, or 1:1 for 2 weeks. In Group 2, vehicle or pioglitazone (0.1, 1, 10, 80 mg/kg) was administered 4 h prior to flurothyl exposure. In Group 3, vehicle or increasing doses of pioglitazone were administered to KD-treated mice 4 h prior to flurothyl exposure. Latency times to clonic seizures and generalized tonic-clonic (GTC) seizures were recorded, and isobolographic analysis was used to determine combinatorial interactions.

RESULTS

Neither KD treatment nor pioglitazone alone or in combination affected clonic seizures. However, the latency to GTC seizures was dose-dependently and significantly increased by both KD (~57%, p < 0.05) and pioglitazone (~28%, p < 0.05). Coadministration of an ineffective 1:1 KD and pioglitazone resulted in ~47-55% (p < 0.05) increase in latency to GTC. Isobolographic analysis indicated a synergistic interaction of the KD and pioglitazone.

SIGNIFICANCE

These results suggest coadministration may enable reduction of the KD ratio without loss of seizure protection. Such adjuvant treatment could improve quality of life and limit adverse effects of a classic KD or high-dose pioglitazone.

Early-life febrile seizures worsen adult phenotypes in Scn1a mutants

Mutations in the voltage-gated sodium channel (VGSC) gene SCN1A, encoding the Na_v1.1 channel, are responsible for a number of epilepsy disorders including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome (DS). Patients with SCN1A mutations often experience prolonged early-life febrile seizures (FSs), raising the possibility that these events may influence epileptogenesis and lead to more severe adult phenotypes. To test this hypothesis, we subjected 21-23-day-old mice expressing the human SCN1A GEFS+ mutation R1648H to prolonged hyperthermia, and then examined seizure and behavioral phenotypes during adulthood. We found that early-life FSs resulted in lower latencies to induced seizures, increased severity of spontaneous seizures, hyperactivity, and impairments in social behavior and recognition memory during adulthood. Biophysical analysis of brain slice preparations revealed an increase in epileptiform activity in CA3 pyramidal neurons along with increased action potential firing, providing a mechanistic basis for the observed worsening of adult phenotypes. These findings demonstrate the long-term negative impact of early-life FSs on disease outcomes. This has important implications for the clinical management of this patient population and highlights the need for therapeutic interventions that could ameliorate disease progression.

Dravet syndrome: a new causative SCN1A mutation?

Dravet syndrome is often caused by SCN1A mutations and has a wide variation in clinical appearance. Indication for genetic analysis should be an epileptic encephalopathy or severe clinical course of seizures in infants with episodes of fever before the first year of life.

Dravet syndrome is often caused by SCN1A mutations and has a wide variation in clinical appearance. Indication for genetic analysis should be an epileptic encephalopathy or severe clinical course of seizures in infants with episodes of fever before the first year of life.

Huperzine A Provides Robust and Sustained Protection against Induced Seizures in Scn1a Mutant Mice

De novo loss-of-function mutations in the voltage-gated sodium channel (VGSC) SCN1A (encoding Na_v1.1) are the main cause of Dravet syndrome (DS), a catastrophic early-life encephalopathy associated with prolonged and recurrent early-life febrile seizures (FSs), refractory afebrile epilepsy, cognitive and behavioral deficits, and a 15–20% mortality rate. SCN1A mutations also lead to genetic epilepsy with febrile seizures plus (GEFS+), which is an inherited disorder characterized by early-life FSs and the development of a range of adult epilepsy subtypes. Current antiepileptic drugs often fail to protect against the severe seizures and behavioral and cognitive deficits found in patients with SCN1A mutations. To address the need for more efficacious treatments for SCN1A-derived epilepsies, we evaluated the therapeutic potential of Huperzine A, a naturally occurring reversible acetylcholinesterase inhibitor. In CF1 mice, Hup A (0.56 or 1 mg/kg) was found to confer protection against 6 Hz-, pentylenetetrazole (PTZ)-, and maximal electroshock (MES)-induced seizures. Robust protection against 6 Hz-, MES-, and hyperthermia-induced seizures was also achieved following Hup A administration in mouse models of DS (Scn1a^+/−) and GEFS+ (Scn1a^RH/+). Furthermore, Hup A-mediated seizure protection was sustained during 3 weeks of daily injections in Scn1a^RH/+ mutants. Finally, we determined that muscarinic and GABA_A receptors play a role in Hup A-mediated seizure protection. These findings indicate that Hup A might provide a novel therapeutic strategy for increasing seizure resistance in DS and GEFS+, and more broadly, in other forms of refractory epilepsy.

Palliative epilepsy surgery in Dravet syndrome-case series and review of the literature

PURPOSE

Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy (SMEI), is a rare genetic disorder that results in severe childhood-onset epilepsy. Children with DS initially present with seizures in the first year of life that are often associated with fevers. With age, multiple seizure types develop. There are few reports and no guidelines regarding palliative surgical treatment for DS. Therefore, we reviewed our surgical experience with DS.

METHODS

We conducted a retrospective review of all patients with genetically confirmed DS who underwent either vagal nerve stimulator (VNS) implantation or corpus callosotomy (CC) from May 2001 to April 2014 at our institution. All inpatient and outpatient relevant documentation were reviewed. Demographic information, genetic mutation, operation performed, and preoperative and postoperative seizure frequency were recorded. Inclusion criteria required greater than one-year postoperative follow-up.

RESULTS

Seven children with DS were assessed. Six patients were treated with VNS and one patient was treated with CC. In one child, VNS was followed by CC as a secondary procedure. Therefore, in total, eight surgeries were performed on seven patients during the study period. At least 1 year elapsed from presentation to our hospital and surgery for all patients. Average time after the first seizure to VNS was 4.1 years, and the average time after the first seizure to CC was 7.6 years. The mean age of patients undergoing VNS implantation was 4.3 years, and the mean age for patients undergoing CC was eight. Average follow-up for all seven patients was 6.6 years. Seizures were decreased in five of the six patients with VNS and decreased in the two patients after CC. Four of the six patients who had VNS implanted had a greater than 50 % reduction in seizure frequency, and one of the six patients who had VNS implanted had a less than 50 % reduction in seizure frequency. One patient did not respond effectively to the VNS and had very limited change in seizure frequency. Both patients who had a CC had a greater than 50 % reduction in seizure frequency.

CONCLUSIONS

Both VNS and CC in patients with DS can be effective at reducing seizure frequency. Patients with DS may benefit from earlier and more aggressive surgical intervention. Studies using larger patient cohorts will help clarify the role that surgery may play in the multidisciplinary approach to controlling seizures in DS. Further studies will help determine the appropriate timing of and type of surgical intervention.

Ketogenic diet treatment increases longevity in Kcna1-null mice, a model of sudden unexpected death in epilepsy

Individuals with poorly controlled epilepsy have a higher risk for sudden unexpected death in epilepsy (SUDEP). With approximately one third of people with epilepsy not achieving adequate seizure control with current antiseizure drugs, there is a critical need to identify treatments that reduce risk factors for SUDEP. The Kcna1-null mutant mouse models risk factors and terminal events associated with SUDEP. In the current study, we demonstrate the progressive nature of epilepsy and sudden death in this model (mean age of mortality (± SEM), postnatal day [P] 42.8 ± 1.3) and tested the hypothesis that long-term treatment with the ketogenic diet (KD) will prolong the life of Kcna1-null mice. We found that the KD postpones disease progression by delaying the onset of severe seizures and increases the lifespan of these mutant mice by 47%. Future studies are needed to determine the mechanisms underlying the KD effects on longevity.

Scn1a dysfunction alters behavior but not the effect of stress on seizure response

Mutations in the voltage-gated sodium channel gene SCN1A are responsible for a number of epilepsy disorders, including genetic epilepsy with febrile seizures plus (GEFS+) and Dravet syndrome. In addition, dysfunction in SCN1A is increasingly being linked to neuropsychiatric abnormalities, social deficits and cognitive disabilities. We have previously reported that mice heterozygous for the SCN1A R1648H mutation identified in a GEFS+ family have infrequent spontaneous seizures, increased susceptibility to chemically and hyperthermia-induced generalized seizures and sleep abnormalities. In this study, we characterized the behavior of heterozygous mice expressing the SCN1A R1648H mutation (Scn1a(RH/+)) and the effect of stress on spontaneous and induced seizures. We also examined the effect of the R1648H mutation on the hypothalamic-pituitary-adrenal (HPA) axis response. We confirmed our previous finding that Scn1a(RH/+) mutants are hyperactive, and also identified deficits in social behavior, spatial memory, cued fear conditioning, pre-pulse inhibition and risk assessment. Furthermore, while exposure to a stressor did increase seizure susceptibility, the effect seen in the Scn1a(RH/+) mutants was similar to that seen in wild-type littermates. In addition, Scn1a dysfunction does not appear to alter HPA axis function in adult animals. Our results suggest that the behavioral abnormalities associated with Scn1a dysfunction encompass a wider range of phenotypes than previously reported and factors such as stress exposure may alter disease severity in patients with SCN1A mutations.

Unaltered Network Activity and Interneuronal Firing During Spontaneous Cortical Dynamics In Vivo in a Mouse Model of Severe Myoclonic Epilepsy of Infancy

Severe myoclonic epilepsy of infancy (SMEI) is associated with loss of function of the SCN1A gene encoding the Na_V1.1 sodium channel isoform. Previous studies in Scn1a^−/+ mice during the pre-epileptic period reported selective reduction in interneuron excitability and proposed this as the main pathological mechanism underlying SMEI. Yet, the functional consequences of this interneuronal dysfunction at the circuit level in vivo are unknown. Here, we investigated whether Scn1a^−/+ mice showed alterations in cortical network function. We found that various forms of spontaneous network activity were similar in Scn1a^−/+ during the pre-epileptic period compared with wild-type (WT) in vivo. Importantly, in brain slices from Scn1a^−/+ mice, the excitability of parvalbumin (PV) and somatostatin (SST) interneurons was reduced, epileptiform activity propagated more rapidly, and complex synaptic changes were observed. However, in vivo, optogenetic reduction of firing in PV or SST cells in WT mice modified ongoing network activities, and juxtasomal recordings from identified PV and SST interneurons showed unaffected interneuronal firing during spontaneous cortical dynamics in Scn1a^−/+ compared with WT. These results demonstrate that interneuronal hypoexcitability is not observed in Scn1a^−/+ mice during spontaneous activities in vivo and suggest that additional mechanisms may contribute to homeostatic rearrangements and the pathogenesis of SMEI.

SCN2A mutation in a Chinese boy with infantile spasm - response to Modified Atkins Diet

BACKGROUND

Mutation of SCN2A, encoding for voltage-gated sodium channel type II alpha subunit, has been demonstrated in various epilepsy phenotypes, ranging from benign to severe epileptic disorders and recently this had been reported for cases with infantile spasm (IS).

METHODS

We study a 6 years-old Chinese boy with severe developmental delay who had infantile spasm since 15 months. He later had severe intellectual disability and autistic features. He failed to respond to most anticonvulsants. Modified Atkins Diet was introduced at 4 years of age and he showed a seizure remission for 12 months with only 1 anticonvulsants. To clarify the unknown etiology, mutations were screened for genes associated with brain development or synaptic function.

RESULTS

A heterozygous mutation (c.3631G>A; p.E1211K) was identified in exon 21 of SCN2A gene. This mutation has been reported previously only in a Japanese patient with IS.

CONCLUSION

This is the first case of SCN2A mutation identified in Chinese. Similarity of our case and one Japanese case of infantile spasm indicated that this E1211K mutation is important as possible etiology of IS. Trial of Modified Atkins Diet for other cases of infantile spasm with similar SCN2A mutations is worthwhile pursuing.

The Ketogenic Diet Does Not Affect Growth of Hedgehog Pathway Medulloblastoma in Mice

The altered metabolism of cancer cells has long been viewed as a potential target for therapeutic intervention. In particular, brain tumors often display heightened glycolysis, even in the presence of oxygen. A subset of medulloblastoma, the most prevalent malignant brain tumor in children, arises as a consequence of activating mutations in the Hedgehog (HH) pathway, which has been shown to promote aerobic glycolysis. Therefore, we hypothesized that a low carbohydrate, high fat ketogenic diet would suppress tumor growth in a genetically engineered mouse model of medulloblastoma. However, we found that the ketogenic diet did not slow the growth of spontaneous tumors or allograft flank tumors, and it did not exhibit synergy with a small molecule inhibitor of Smoothened. Serum insulin was significantly reduced in mice fed the ketogenic diet, but no alteration in PI3 kinase activity was observed. These findings indicate that while the ketogenic diet may be effective in inhibiting growth of other tumor types, it does not slow the growth of HH-medulloblastoma in mice.

Pathogenesis and new candidate treatments for infantile spasms and early life epileptic encephalopathies: A view from preclinical studies

Early onset and infantile epileptic encephalopathies (EIEEs) are usually associated with medically intractable or difficult to treat epileptic seizures and prominent cognitive, neurodevelopmental and behavioral consequences. EIEEs have numerous etiologies that contribute to the inter- and intra-syndromic phenotypic variability. Etiologies include structural and metabolic or genetic etiologies although a significant percentage is of unknown cause. The need to better understand their pathogenic mechanisms and identify better therapies has driven the development of animal models of EIEEs. Several rodent models of infantile spasms have emerged that recapitulate various aspects of the disease. The acute models manifest epileptic spasms after induction and include the NMDA rat model, the NMDA model with prior prenatal betamethasone or perinatal stress exposure, and the γ-butyrolactone induced spasms in a mouse model of Down syndrome. The chronic models include the tetrodotoxin rat model, the aristaless related homeobox X-linked (Arx) mouse models and the multiple-hit rat model of infantile spasms. We will discuss the main features and findings from these models on target mechanisms and emerging therapies. Genetic models have also provided interesting data on the pathogenesis of Dravet syndrome and proposed new therapies for testing. The genetic associations of many of the EIEEs have also been tested in rodent models as to their pathogenicity. Finally, several models have tested the impact of subclinical epileptiform discharges on brain function. The impact of these advances in animal modeling for therapy development will be discussed.

A novel variant in the 3' UTR of human SCN1A gene from a patient with Dravet syndrome decreases mRNA stability mediated by GAPDH's binding

Mutations in the SCN1A gene-encoding voltage-gated sodium channel α-I subunit (Nav1.1) cause various spectrum of epilepsies including Dravet syndrome (DS), a severe and intractable form. A large number of SCN1A mutations identified from the DS patients lead to the loss of function or truncation of Nav1.1 that result in a haploinsufficiency effects, indicating that the exact expression level of SCN1A should be essential to maintain normal brain function. In this study, we have identified five variants c.*1025T>C, c.*1031A>T, c.*1739C>T, c.*1794C>T and c.*1961C>T in the SCN1A 3' UTR in the patients with DS. The c.*1025T>C, c.*1031A>T and c.*1794C>T are conserved among different species. Of all the five variants, only c.*1794C>T is a novel variant and alters the predicted secondary structure of the 3' UTR. We also show that glyceraldehyde-3-phosphate dehydrogenase (GAPDH) only binds to the 3' UTR sequence containing the mutation allele 1794U but not the wild-type allele 1794C, indicating that the mutation allele forms a new GAPDH-binding site. Functional analyses show that the variant negatively regulates the reporter gene expression by affecting the mRNA stability that is mediated by GAPDH's binding, and this phenomenon could be reversed by shRNA-induced GAPDH knockdown. These findings suggest that GAPDH and the 3'-UTR variant are involved in regulating SCN1A expression at post-transcriptional level, which may provide an important clue for further investigating on the relationship between 3'-UTR variants and SCN1A-related diseases.

Purinergic control of hippocampal circuit hyperexcitability in Dravet syndrome

OBJECTIVE

Severe myoclonic epilepsy in infancy (SMEI) or Dravet syndrome is one of the most devastating childhood epilepsies. Children with SMEI have febrile and afebrile seizures (FS and aFS), ataxia, and social and cognitive dysfunctions. SMEI is pharmacologically intractable and can be fatal in 10-20% of patients. It remains to be elucidated how channelopathies that cause SMEI impact synaptic activities in key neural circuits, and there is an ongoing critical need for alternative methods of controlling seizures in SMEI. Using the SCN1A gene knock-in mouse model of SMEI (mSMEI), we studied hippocampal cell and circuit excitability, particularly during hyperthermia, and tested whether an adenosine A1 receptor (A1R) agonist can reliably control hippocampal circuit hyperexcitability.

METHODS

Using a combination of electrophysiology (extracellular and whole-cell voltage clamp) and fast voltage-sensitive dye imaging (VSDI), we quantified synaptic excitation and inhibition, spatiotemporal characteristics of neural circuit activity, and hyperthermia-induced febrile seizure-like events (FSLEs) in juvenile mouse hippocampal slices. We used hyperthermia to elicit FSLEs in hippocampal slices, while making use of adenosine A1R agonist N6-cyclopentyladenosine (CPA) to control abnormally widespread neural activity and FSLEs.

RESULTS

We discovered a significant excitation/inhibition (E/I) imbalance in mSMEI hippocampi, in which inhibition was decreased and excitation increased. This imbalance was associated with an increased spatial extent of evoked neural circuit activation and a lowered FSLE threshold. We found that a low concentration (50 nm) of CPA blocked FSLEs and reduced the spatial extent of abnormal neural activity spread while preserving basal levels of excitatory synaptic transmission.

SIGNIFICANCE

Our study reveals significant hippocampal synapse and circuit dysfunctions in mSMEI and demonstrates that the A1R agonist CPA can reliably control hippocampal hyperexcitability and FSLEs in vitro. These findings may warrant further investigations of purinergic agonists as part of the development of new therapeutic approaches for Dravet syndrome.

The ketogenic diet in Dravet syndrome

Dravet syndrome is an infantile epilepsy syndrome with intractable pleomorphic seizures, cognitive impairment, and a number of comorbidities including ataxia/gait abnormalities and behavioral issues. Antiseizure medications are only partially effective in controlling seizures. Secondary to the intractable epilepsy, patients are often on multiple antiseizure medications with significant accumulative neurotoxic side effects. Specifically for Dravet syndrome, the medical literature includes both laboratory and clinical research that supports the use of the ketogenic diet. In addition, a review of the children with Dravet syndrome who were treated with the ketogenic diet at our center was undertaken. Thirteen of the 20 children (65%) with Dravet syndrome treated with the ketogenic diet experienced a greater than 50% reduction in seizure frequency. The ketogenic diet is a good alternative to medication for seizure management in children with Dravet syndrome.

Ketogenic diet

About one third of patients with epilepsy are pharmacoresistent. For a subgroup of this population, the ketogenic diet can be highly efficacious and should be considered early. This review discusses the different types of ketogenic diet, proposed mechanism of actions and its evidence for use in children and adults with both generalized and focal epilepsies where surgery is not feasible. In addition we discuss a practical approach to diet initiation, maintenance and monitoring for side effects. We also summarize the emerging evidence for the use of ketogenic diet in a broad range of neurological disorders.

Harnessing the power of metabolism for seizure prevention: focus on dietary treatments

The continued occurrence of refractory seizures in at least one-third of children and adults with epilepsy, despite the availability of almost 15 conventional and novel anticonvulsant drugs, speaks to a dire need to develop novel therapeutic approaches. Cellular metabolism, the critical pathway by which cells access and utilize energy, is essential for normal neuronal function. Furthermore, mounting evidence suggests direct links between energy metabolism and cellular excitability. The high-fat, low-carbohydrate ketogenic diet has been used as a treatment for drug-refractory epilepsy for almost a century. Yet, the multitude of alternative therapies to target aspects of cellular metabolism and hyperexcitability is almost untapped. Approaches discussed in this review offer a wide diversity of therapeutic targets that might be exploited by investigators in the search for safer and more effective epilepsy treatments.

Novel animal models of pediatric epilepsy

When mimicking epileptic processes in a laboratory setting, it is important to understand the differences between experimental models of seizures and epilepsy. Because human epilepsy is defined by the appearance of multiple spontaneous recurrent seizures, the induction of a single acute seizure without recurrence does not constitute an adequate epilepsy model. Animal models of epilepsy might be useful for various tasks. They allow for the investigation of pathophysiological mechanisms of the disease, the evaluation, or the development of new antiepileptic treatments, and the study of the consequences of recurrent seizures and neurological and psychiatric comorbidities. Although clinical relevance is always an issue, the development of models of pediatric epilepsies is particularly challenging due to the existence of several key differences in the dynamics of human and rodent brain maturation. Another important consideration in modeling pediatric epilepsy is that "children are not little adults," and therefore a mere application of models of adult epilepsies to the immature specimens is irrelevant. Herein, we review the models of pediatric epilepsy. First, we illustrate the differences between models of pediatric epilepsy and models of the adulthood consequences of a precipitating insult in early life. Next, we focus on new animal models of specific forms of epilepsies that occur in the developing brain. We conclude by emphasizing the deficiencies in the existing animal models and the need for several new models.