Genetic Epilepsy Research Articles

Advances in Therapy for Refractory Epilepsy.

Drug-resistant epilepsy (DRE) is defined as failure to achieve sustained seizure control with adequate trials of two appropriate antiseizure medications (ASMs). DRE affects one-third of patients with epilepsy and is associated with significant morbidity and mortality. Newer ASMs provide pharmacological therapy that is better tolerated but not necessarily more effective than older ASMs. Resective brain surgery is the gold standard to treat DRE and achieve seizure freedom, with laser ablation offering an alternative with less morbidity but lower effectiveness. For patients who are not candidates for resection or ablation, multiple neuromodulation options can reduce seizure burden. These neuromodulation devices have shown comparable effectiveness in randomized clinical trials, but the results vary in open-label follow-up cohorts, as do the risks of complications and associated costs. Dietary therapies can help, particularly in pediatric genetic epilepsies. Innovative genetic therapy approaches are being pursued, offering the promise of precision medicine.

Whole exome sequencing-based testing of adult epilepsy in a Polish population.

Genetic panel testing in paediatric and mixed adult and children populations has demonstrated clinical utility and provided a diagnostic yield of 18-40%. The data on adult epilepsies is limited. We aimed to investigate the diagnostic yield and analyse genetic diagnoses in whole exome sequenced adult patients with epilepsies in Poland. We recruited 151 patients from 42 clinical centres across Poland. The patients had a diagnosis of epilepsy/ seizures, were 18 or older at the time of the genetic testing, and did not have a genetic diagnosis. All patients were tested with whole exome sequencing after an initial testing with a panel of 47 epilepsy-related genes. We reached a diagnostic yield when considering pathogenic/probably pathogenic variants according to ClinVar of 8.6% (n = 13) and 17% (n = 26) when applying the American College of Medical Genetics (ACMG) criteria. Most patients had a pathogenic/probably pathogenic variant in epilepsy-related genes (54%), followed by potential epilepsy-related genes (19%), and neurodevelopment-associated epilepsy genes (15%). Our study shows that whole exome sequencing-based testing reaches a slightly higher diagnostic yield that the traditional 300 gene panel. Genes related to childhood onset neurodevelopmental disorders and epilepsy should be considered as well. Clinical implications/future directions. Patients may have had a diagnosis related to a childhood syndrome, but due to limited diagnostic possibilities, it was not possible to diagnose them in childhood. We would consider testing adult patients with epilepsy with whole exome or genome sequencing (or if not possible with a panel) in cases of a diagnosis of epilepsy with no hints suggesting secondary epilepsy, and especially with clinical features indicating a genetic epilepsy diagnosis, such as neurodevelopmental delay and early onset of seizures.

Novel antiseizure medications in the development pipeline: promising candidates and recent failures

AbstractIn the past decade, we have observed a paradigm shift in the discovery of novel antiseizure medications (ASMs), which is a consequence of significant progress in epilepsy genetics, the availability of novel disease models, drug-screening technologies, the discovery of new mechanisms of action, expanding existing drugs into new populations, or new routes of delivery. This resulted in a very rich pipeline of potential future treatments for epilepsy, including gene-modifying treatments for rare genetic epilepsies and mechanistically guided precision treatments. Hopes are high that this pipeline may bring therapeutic breakthroughs similar to those recently achieved with cenobamate for the common drug-resistant focal epilepsy and fenfluramine for seizures in Dravet syndrome. Furthermore, we stand at the beginning of a new era of epilepsy treatment expansion, from traditional seizure suppression to disease prevention and modification. This review discusses the most advanced and promising candidates in the clinical development pipeline but also describes recent failures in the development of novel ASMs.

Solving the Etiology of Developmental and Epileptic Encephalopathy with Spike-Wave Activation in Sleep (D/EE-SWAS).

To understand the etiological landscape and phenotypic differences between 2 developmental and epileptic encephalopathy (DEE) syndromes: DEE with spike-wave activation in sleep (DEE-SWAS) and epileptic encephalopathy with spike-wave activation in sleep (EE-SWAS). All patients fulfilled International League Against Epilepsy (ILAE) DEE-SWAS or EE-SWAS criteria with a Core cohort (n = 91) drawn from our Epilepsy Genetics research program, together with 10 etiologically solved patients referred by collaborators in the Expanded cohort (n = 101). Detailed phenotyping and analysis of molecular genetic results were performed. We compared the phenotypic features of individuals with DEE-SWAS and EE-SWAS. Brain-specific gene co-expression analysis was performed for D/EE-SWAS genes. We identified the etiology in 42/91 (46%) patients in our Core cohort, including 29/44 (66%) with DEE-SWAS and 13/47 (28%) with EE-SWAS. A genetic etiology was identified in 31/91 (34%). D/EE-SWAS genes were highly co-expressed in brain, highlighting the importance of channelopathies and transcriptional regulators. Structural etiologies were found in 12/91 (13%) individuals. We identified 10 novel D/EE-SWAS genes with a range of functions: ATP1A2, CACNA1A, FOXP1, GRIN1, KCNMA1, KCNQ3, PPFIA3, PUF60, SETD1B, and ZBTB18, and 2 novel copy number variants, 17p11.2 duplication and 5q22 deletion. Although developmental regression patterns were similar in both syndromes, DEE-SWAS was associated with a longer duration of epilepsy and poorer intellectual outcome than EE-SWAS. DEE-SWAS and EE-SWAS have highly heterogeneous genetic and structural etiologies. Phenotypic analysis highlights valuable clinical differences between DEE-SWAS and EE-SWAS which inform clinical care and prognostic counseling. Our etiological findings pave the way for the development of precision therapies. ANN NEUROL 2024;96:932-943.

Investigating the effect of polygenic background on epilepsy phenotype in ‘monogenic’ families

Phenotypic variability within families with epilepsy is often observed, even when relatives share the same monogenic cause. We aimed to investigate whether common polygenic risk for epilepsy could explain the penetrance and phenotypic expression of rare pathogenic variants in familial epilepsies. We studied 58 clinically heterogeneous families with genetic epilepsy with febrile seizures plus (GEFS+). Relatives were coded as either unaffected or affected with epilepsy, and graded according to phenotype severity: no seizures, febrile seizures (FS) only, febrile seizures plus (FS+), generalised/focal epilepsy, or developmental and epileptic encephalopathy (DEE). Epilepsy polygenic risk scores (PRSs) were tested for association with epilepsy phenotype. Within families, the mean PRS difference was compared between pairs concordant versus discordant for phenotype severity. Statistical analyses were performed using mixed-effect regression models. 304 individuals segregating a known, or presumed, rare variant of large effect, were studied. Within families, higher epilepsy polygenic risk was associated with an epilepsy diagnosis (OR=1.39, 95% CI 1.08, 1.80, padj=0.040). Relatives with a more severe phenotype had a mean pairwise PRS difference of+0.19 higher than relatives with a milder phenotype (padj=0.010). The difference increased with greater phenotype discordance between relatives. As the cohort included two rare variants with >30 relatives each, variant-specific genotype-phenotype associations could also be analysed. Whilst the epilepsy PRS effect was strong for relatives segregating the GABRG2 p.Arg82Gln pathogenic variant (padj=0.0010), the effect was not significant for SCN1B p.Cys121Trp. We provide support for genetic background modifying the penetrance and phenotypic expression of rare variants associated with 'monogenic' epilepsies. In GEFS+families, relatives with higher epilepsy PRSs were more likely to show penetrance (epilepsy diagnosis) and a more severe phenotype. Variant-specific analyses suggest that some rare variants may be more susceptible to PRS modification, carrying important genetic counselling and disease prognostication implications for patients. National Health and Medical Research Council of Australia, Medical Research Future Fund of Australia.

Exploring the Frontier: The Human Microbiome’s Role in Rare Childhood Neurological Diseases and Epilepsy

Emerging research into the human microbiome, an intricate ecosystem of microorganisms residing in and on our bodies, reveals that it plays a pivotal role in maintaining our health, highlighting the potential for microbiome-based interventions to prevent, diagnose, treat, and manage a myriad of diseases. The objective of this review is to highlight the importance of microbiome studies in enhancing our understanding of rare genetic epilepsy and related neurological disorders. Studies suggest that the gut microbiome, acting through the gut–brain axis, impacts the development and severity of epileptic conditions in children. Disruptions in microbial composition can affect neurotransmitter systems, inflammatory responses, and immune regulation, which are all critical factors in the pathogenesis of epilepsy. This growing body of evidence points to the potential of microbiome-targeted therapies, such as probiotics or dietary modifications, as innovative approaches to managing epilepsy. By harnessing the power of the microbiome, we stand to develop more effective and personalized treatment strategies for children affected by this disease and other rare neurological diseases.

Exome Sequencing of Consanguineous Pashtun Families With Familial Epilepsy Reveals Causative and Candidate Variants in TSEN54, MOCS2, and OPHN1.

Next-generation sequencing is advancing in low- and middle-income countries, but accessibility remains limited. In Pakistan, many members of the Pashtun population practice familial marriage and maintain distinct socio-cultural traditions, isolating them from other ethnic groups. As a result, they may harbor genetic variants that could unveil new gene-disease associations. To investigate the genetic basis of epilepsy in the Pashtun community we recently established a collaboration between Bannu University and the University of Tuebingen. Here we report our first results of exome sequencing of four families with presumed monogenetic epilepsy and Mendelian inheritance pattern. In Family #201, we identified distinct disease-causing variants. One had a homozygous pathogenic missense variant in TSEN54 (c.919G > T, p.(Ala307Ser)), linked to Pontocerebellar Hypoplasia Type 2A. The second individual had a homozygous class IV missense variant in MOCS2 (c.226G > A, p.(Gly76Arg)) which is associated with Molybdenum cofactor deficiency. In family EP02, one affected individual carried a heterozygous class III variant in OPHN1 (c.1490G > A, p.(Arg497Gln)), related to syndromic X-linked intellectual disability with epilepsy. Our small study demonstrates the promise of next-generation sequencing in genetic epilepsies among the Pashtun population. Diagnostic next-generation sequencing should be established in Pakistan as soon as possible, and if not feasible, genetic research projects may pioneer this path.

Quantitative EEG Spectral Features Differentiate Genetic Epilepsies and Predict Neurologic Outcomes.

EEG plays an integral part in the diagnosis and management of children with genetic epilepsies. Nevertheless, how quantitative EEG features differ between genetic epilepsies and neurological outcomes remains largely unknown. Here, we aimed to identify quantitative EEG biomarkers in children with epilepsy and a genetic diagnosis in STXBP1 , SCN1A , or SYNGAP1 , and to assess how quantitative EEG features associate with neurological outcomes in genetic epilepsies more broadly. We analyzed individuals with pathogenic variants in STXBP1 (95 EEGs, n =20), SCN1A (154 EEGs, n =68), and SYNGAP1 (46 EEGs, n =21) and a control cohort of individuals without epilepsy or known cerebral disease (847 EEGs, n =806). After removing artifacts and epochs with excess noise or altered state from EEGs, we extracted spectral features. We validated our preprocessing pipeline by comparing automatically-detected posterior dominant rhythm (PDR) to annotations from clinical EEG reports. Next, as a coarse measure of pathological slowing, we compared the alpha-delta bandpower ratio between controls and the different genetic epilepsies. We then trained random forest models to predict a diagnosis of STXBP1 , SCN1A , and SYNGAP1 . Finally, to understand how EEG features vary with neurological outcomes, we trained random forest models to predict seizure frequency and motor function. There was strong agreement between the automatically-calculated PDR and clinical EEG reports ( R 2 =0.75). Individuals with STXBP1 -related epilepsy have a significantly lower alpha-delta ratio than controls ( P< 0.001) across all age groups. Additionally, individuals with a missense variant in STXBP1 have a significantly lower alpha-delta ratio than those with a protein-truncating variant in toddlers ( P< 0.001), children ( P =0.02), and adults ( P< 0.001). Models accurately predicted a diagnosis of STXBP1 (AUC=0.91), SYNGAP1 (AUC=0.82), and SCN1A (AUC=0.86) against controls and from each other in a three-class model (accuracy=0.74). From these models, we isolated highly correlated biomarkers for these respective genetic disorders, including alpha-theta ratio in frontal, occipital, and parietal electrodes with STXBP1 , SYNGAP1 , and SCN1A , respectively. Models were unable to predict seizure frequency (AUC=0.53). Random forest models predicted motor scores significantly better than age-based null models ( P< 0.001), suggesting spectral features contain information pertinent to gross motor function. In summary, we demonstrate that STXBP1 -, SYNGAP1- , and SCN1A -related epilepsies have distinct quantitative EEG signatures. Furthermore, EEG spectral features are predictive of some functional outcome measures in patients with genetic epilepsies. Large-scale retrospective quantitative analysis of clinical EEG has the potential to discover novel biomarkers and to quantify and track individuals' disease progression across development.

Cannabinoids and Genetic Epilepsy Models: A Review with Focus on CDKL5 Deficiency Disorder

Pediatric genetic epilepsies, such as CDKL5 Deficiency Disorder (CDD), are severely debilitating, with early-onset seizures occurring more than ten times daily in extreme cases. Existing antiseizure drugs frequently prove ineffective, which significantly impacts child development and diminishes the quality of life for patients and caregivers. The relaxation of cannabis legislation has increased research into potential therapeutic properties of phytocannabinoids such as cannabidiol (CBD) and Δ9-tetrahydrocannabinol (THC). CBD’s antiseizure properties have shown promise, particularly in treating drug-resistant genetic epilepsies associated with Lennox–Gastaut syndrome (LGS), Dravet syndrome (DS), and Tuberous Sclerosis Complex (TSC). However, specific research on CDD remains limited. Much of the current evidence relies on anecdotal reports of artisanal products lacking accurate data on cannabinoid composition. Utilizing model systems like patient-derived iPSC neurons and brain organoids allows precise dosing and comprehensive exploration of cannabinoids’ pharmacodynamics. This review explores the potential of CBD, THC, and other trace cannabinoids in treating CDD and focusing on clinical trials and preclinical models to elucidate the cannabinoid’s potential mechanisms of action in disrupted CDD pathways and strengthen the case for further research into their potential as anti-epileptic drugs for CDD. This review offers an updated perspective on cannabinoid’s therapeutic potential for CDD.

Voltage-gated potassium channels and genetic epilepsy.

Recent advances in exome and targeted sequencing have significantly improved the aetiological diagnosis of epilepsy, revealing an increasing number of epilepsy-related pathogenic genes. As a result, the diagnosis and treatment of epilepsy have become more accessible and more traceable. Voltage-gated potassium channels (Kv) regulate electrical excitability in neuron systems. Mutate Kv channels have been implicated in epilepsy as demonstrated in case reports and researches using gene-knockout mouse models. Both gain and loss-of-function of Kv channels lead to epilepsy with similar phenotypes through different mechanisms, bringing new challenges to the diagnosis and treatment of epilepsy. Research on genetic epilepsy is progressing rapidly, with several drug candidates targeting mutated genes or channels emerging. This article provides a brief overview of the symptoms and pathogenesis of epilepsy associated with voltage-gated potassium ion channels dysfunction and highlights recent progress in treatments. Here, we reviewed case reports of gene mutations related to epilepsy in recent years and summarized the proportion of Kv genes. Our focus is on the progress in precise treatments for specific voltage-gated potassium channel genes linked to epilepsy, including KCNA1, KCNA2, KCNB1, KCNC1, KCND2, KCNQ2, KCNQ3, KCNH1, and KCNH5.

Huperzine A suppresses absence seizures in the genetic absence epilepsy rat from Strasbourg (GAERS) model of genetic generalized epilepsy with absence seizures.

We evaluated huperzine A treatment in the Genetic Absence Epilepsy Rat from Strasbourg (GAERS) model of genetic generalized epilepsy (GGE) with absence seizures. Adult male GAERS (N = 15) were implanted with EEG recording electrodes 10 days before receiving study drug. Each animal received the following six treatments as a single, intraperitoneal dose, 7 days apart (in random order): huperzine A (0.3, 1.0, or 3.0 mg/kg), two periods of vehicle (0.9% NaCl), or ethosuximide (100 mg/kg) as a positive control. Electroencephalograms (EEGs) were acquired for 24 h before and after each treatment and analyzed for seizure activity during the 90-min period immediately post-treatment, including 30-min intervals at 30, 60, and 90 min. Additional analyses evaluated seizure activity over the 24-h post-treatment period using 60-min intervals at 6, 12, and 24 h. The cumulative 24-h periods before and after each administered treatment were also compared. Two-way ANOVA showed a treatment difference [F(91,182) = 3.592, p < 0.0001] on the number of seizures over the first 90-min post-treatment (primary outcome); Tukey's post hoc analyses showed that, compared to vehicle, huperzine A (3.0 mg/kg) significantly reduced seizures in the 30-min (p = 0.02) and 60-min (p = 0.001) intervals, and ethosuximide significantly reduced seizures at all measured time intervals except the 1-h blocks at 12 and 24 h. Huperzine A 3.0 mg/kg and ethosuximide significantly reduced seizures during the cumulative 24-h post-treatment period relative to pretreatment baseline. While huperzine A 3.0 mg/kg did not differ significantly from ethosuximide at any time point, the study was not designed to evaluate non-inferiority. The only adverse event after huperzine A or ethosuximide was mild, dose-dependent sedation. Huperzine A potently suppressed absence-like seizures in GAERS, albeit with a shorter duration of action relative to ethosuximide, showing promise for clinical efficacy in GGE. This study looked at how huperzine A affects seizures in rats with similar abnormal brain activity as seen in humans with absence epilepsy. Rats received different treatments, placebo (i.e., saline solution), huperzine A, and ethosuximide. Ethosuximide is considered a gold standard treatment for absence epilepsy. We recorded brain activity to measure seizures before and after each treatment. We found that huperzine A (3.0 mg/kg) reduced seizures soon after treatment, like ethosuximide. Both treatments appeared safe, causing only mild sleepiness. The study shows that huperzine A could be a good new treatment for a type of absence epilepsy.

Baseline characteristics and predictors for early implantation of vagus nerve stimulation therapy in people with drug-resistant epilepsy: Observations from an international prospective outcomes registry (CORE-VNS).

Vagus nerve stimulation (VNS) Therapy is routinely indicated for people with drug-resistant epilepsy (DRE). We analyzed the baseline characteristics of individuals receiving the recently released VNS models and identified factors associated with early or late implantation. The Comprehensive Outcomes Registry of subjects with Epilepsy (CORE-VNS), a prospective observational study evaluating the clinical and psychosocial outcomes of VNS Therapy®, is following participants for up to 60 months after VNS implantation. In this analysis, we used Cox proportional hazards model to identify baseline characteristics associated with the time from diagnosis to first implantation. Of the 819 enrolled, 792 (96.7%) participants implanted with a VNS device were evaluated. 529 (64.6%) underwent the first implantation and 263 (32.1%) a re-implantation. Participants' median age at first implant was 24 years; 492 (62.1%) were ≥18 years old and 166 (20.3%) were < 12 years old. The average number of failed ASMs prior to VNS implantation was 7.1, and 145 (17.7%) had undergone previous epilepsy-related surgery. Epilepsy was classified as focal in 47.7% of participants, generalized in 16.1% and combined focal and generalized in 34.2%. Many of the participants (40.9%) had epilepsy of unknown etiology. The median time from diagnosis to first implantation was 10.33 years and was significantly shorter in participants with combined focal and generalized epilepsy compared to those with focal epilepsy alone, and in participants with genetic and immune epilepsy compared to those with unknown etiologies. In people with DRE, VNS Therapy is provided after multiple failures of ASMs and after failure of epilepsy surgery in one in six individuals. Time from diagnosis to first implantation is associated with epilepsy type and etiology, likely reflecting variable treatment pathways. Clearer guidelines on when and how non-drug therapies should be deployed in people with DRE related to different epilepsy factors are needed. Neuromodulation can be a very helpful treatment in people who have seizures that do not respond to medications. The most widely utilized neuromodulation therapy is vagus nerve stimulation (VNS). We present data from a large, global study to show that people use an average of seven anti-seizure medications before attempting VNS Therapy and that it takes about 10 years for people to get their first VNS implant. We advocate for clearer treatment guidelines on how and when to consider VNS Therapy in people with seizures that are resistant to medication.

Unraveling the shared genetics of common epilepsies and general cognitive ability

PurposeCognitive impairment is prevalent among individuals with epilepsy, and increasing evidence indicates that genetic factors can underlie this relationship. However, the extent to which epilepsy subtypes differ in their genetic relationship with cognitive function, and information about the specific genetic variants involved remain largely unknown. MethodsWe investigated the genetic relationship between epilepsies and general cognitive ability (COG) using complementary statistical tools, including linkage disequilibrium score (LDSC) regression, MiXeR and conjunctional false discovery rate (conjFDR). We analyzed genome-wide association study data on COG (n = 269,867) and common epilepsies (n = 27,559 cases, 42,436 controls), including the broad phenotypes ‘all epilepsy’, focal epilepsies and genetic generalized epilepsies (GGE), as well as specific subtypes. We functionally annotated the identified loci using several biological resources and validated the results in independent samples. ResultsUsing MiXeR, COG (11.2k variants) was estimated to be almost four times more polygenic than ‘all epilepsy’, GGE, juvenile myoclonic epilepsy (JME), and childhood absence epilepsy (CAE) (2.5k – 2.9k variants). The other epilepsy phenotypes were insufficiently powered for MiXeR analysis. We quantified extensive genetic overlap between COG and epilepsy types, but with varying negative genetic correlations (-0.23 to -0.04). COG was estimated to share 2.9k variants with both GGE and ‘all epilepsy’, and 2.3k variants with both JME and CAE. Using conjFDR, we identified 66 distinct loci shared between COG and epilepsies, including novel associations for GGE (27), ‘all epilepsy’ (5), JME (5) and CAE (5). The implicated genes were significantly expressed in multiple brain regions. The results were validated in independent samples (COG: p = 3.62 × 10–7; ‘all epilepsy’: p = 2.58 × 10–3). ConclusionOur study further dissects the substantial genetic basis shared between epilepsies and COG and identifies novel shared loci. An improved understanding of the genetic relationship between epilepsies and COG may lead to the development of novel comorbidity-targeted epilepsy treatments.

Altered development and network connectivity in a human neuronal model of 15q11.2 deletion-related neurodevelopmental disorders.

The chromosome 15q11.2 locus is deleted in 1.5% of patients with genetic epilepsy and confers a risk for intellectual disability and schizophrenia. Individuals with this deletion demonstrate increased cortical thickness, decreased cortical surface area and white matter abnormalities. Human induced pluripotent stem cell (iPSC)-derived neural progenitor cells (NPC) from 15q11.2 deletion individuals exhibit early adhesion junction and migration abnormalities, but later neuronal development and function have not been fully assessed. Imaging studies indicating altered structure and network connectivity in the anterior brain regions and the cingulum suggest that in addition to alterations in progenitor dynamics, there may also be structural and functional changes within discrete networks of mature neurons. To explore this, we generated human forebrain cortical neurons from iPSCs derived from individuals with or without 15q11.2 deletion and used longitudinal imaging and multielectrode array analysis to evaluate neuronal development over time. 15q11.2 deleted neurons exhibited fewer connections and an increase in inhibitory neurons. Individual neurons had decreased neurite complexity and overall decreased neurite length. These structural changes were associated with a reduction in multiunit action potential generation, bursting and synchronization. The 15q11.2 deleted neurons also demonstrated specific functional deficits in glutamate and GABA mediated network activity and synchronization with a delay in the maturation of the inhibitory response to GABA. These data indicate that deletion of the 15q11.2 region is sufficient to impair the structural and functional maturation of cortical neuron networks which likely underlies the pathologic changes in humans with the 15q11.2 deletion.

Short-term effectiveness and side effects of ketogenic diet for drug-resistant epilepsy in children with genetic epilepsy syndromes.

Drug-resistant epilepsy (DRE) impacts a significant portion, one-third, of individuals diagnosed with epilepsy. In such cases, exploring non-pharmacological interventions are crucial, with the ketogenic diet (KD) standing out as a valuable option. KD, a high-fat and low-carb dietary approach with roots dating back to the 1920s for managing DRE, triggers the formation of ketone bodies and modifies biochemistry to aid in seizure control. Recent studies have increasingly supported the efficacy of KD in addressing DRE, showcasing positive outcomes. Furthermore, while more research is needed, limited data suggests that KD May also be beneficial for specific genetic epilepsy syndromes (GESs). This study aimed to assess the short-term efficacy of KD among pediatric patients diagnosed with GESs. This is a multi-center retrospective analysis of pediatric patients with GESs diagnosed using next-generation sequencing. The enrolled patients followed the keto-clinic protocol, and the KD efficacy was evaluated at 3, 6, and 12-month intervals based on seizure control and compliance. The collection instrument included demographic, baseline, and prognostic data. The collected data was coded and analyzed promptly. We enrolled a cohort of 77 patients with a mean current age of 7.94 ± 3.83 years. The mean age of seizure onset was 15.5 months. Notably, patients experienced seizures at a younger age tended to have less positive response to diet. Overall, 55 patients responded favorably to the diet (71.4%) while 22 patients (28.6%) showed no improvement. Patients with genetic etiology showed a significantly more favorable responses to the dietary intervention. Patients with Lennox-Gastaut syndrome showed the most significant improvement (14/15) followed by patients with Dravet syndrome (6/8), and West syndrome (3/4). The number of used anti-seizure medications also played a significant role in determining their response to the diet. While some patients experienced mild adverse events, the most common being constipation, these occurrences were not serious enough to necessitate discontinuation of the diet. The study revealed a high improvement rate in seizure control, especially among younger patients and those with later seizure onset. The success of dietary treatment hinges greatly on early intervention and the patient's age. Certain genetic mutations responded favorably to the KD, while efficacy varied among various genetic profiles.

The role of genetic testing in adult patients with unexplained epilepsy.

Genetic causes are often overlooked in patients with epilepsy of unknown etiology, particularly in adults. We aimed to evaluate clinical features of genetic epilepsy and the utility of genetic testing. We retrospectively screened consecutive unrelated adult epilepsy patients at an epilepsy clinic from April 2022 to May 2023. Patients with unknown etiology or special brain lesions were classified as unexplained epilepsy. In them, patients with young-onset seizures or family history of seizures who were recommended for and ultimately underwent genetic testing using either panel next-generation sequencing (NGS) or whole-exome sequencing (WES) were enrolled. A definite or probable genetic diagnosis was established through genotype-phenotype correlation. We compared the demographic characteristics between genetic epilepsy and other etiologies. Of the 374 adult epilepsy patients, 258 were classified as unexplained epilepsy, 129 were suspected of having genetic epilepsy due to young-onset seizures or a positive family history, 33 underwent genetic testing; 13 harbored variants classified as pathogenic, and 6 reached a definite genetic diagnosis, resulting in a yield of 18%. Among the 27 patients without a definite genetic diagnosis, 7 had a nongenetic structural etiology. Patients with genetic etiology exhibited greater multisystem involvement particularly multiple structural anomalies and early childhood-onset seizures, but wasn't directly correlated with young-onset seizures or a positive family history. The diagnostic yield was comparable between panel NGS and WES. In adult patients with unexplained epilepsy, genetic epilepsy is more associated with multisystem involvement and multiple structural anomalies but not family history of seizures or young-onset seizures.

Preoptic area controls sleep-related seizure onset in a genetic epilepsy mouse model.

In genetic and refractory epileptic patients, seizure activity exhibits sleep-related modulation/regulation and sleep and seizure are intermingled. In this study, by using one het Gabrg2 Q390X KI mice as a genetic epilepsy model and optogenetic method in vivo , we found that subcortical POA neurons were active within epileptic network from the het Gabrg2 Q390X KI mice and the POA activity preceded epileptic (poly)spike-wave discharges(SWD/PSDs) in the het Gabrg2 Q390X KI mice. Meanwhile, as expected, the manipulating of the POA activity relatively altered NREM sleep and wake periods in both wt and the het Gabrg2 Q390X KI mice. Most importantly, the short activation of epileptic cortical neurons alone did not effectively trigger seizure activity in the het Gabrg2 Q390X KI mice. In contrast, compared to the wt mice, combined the POA nucleus activation and short activation of the epileptic cortical neurons effectively triggered or suppressed epileptic activity in the het Gabrg2 Q390X KI mice, indicating that the POA activity can control the brain state to trigger seizure incidence in the het Gabrg2 Q390X KI mice in vivo. In addition, the suppression of POA nucleus activity decreased myoclonic jerks in the Gabrg2 Q390X KI mice. Overall, this study discloses an operational mechanism for sleep-dependent seizure incidence in the genetic epilepsy model with the implications for refractory epilepsy. This operational mechanism also underlies myoclonic jerk generation, further with translational implications in seizure treatment for genetic/refractory epileptic patients and with contribution to memory/cognitive deficits in epileptic patients.

Modeling Cortical Versus Hippocampal Network Dysfunction in a Human Brain Assembloid Model of Epilepsy and Intellectual Disability.

Neurodevelopmental disorders often impair multiple cognitive domains. For instance, a genetic epilepsy syndrome might cause seizures due to cortical hyperexcitability and present with memory impairments arising from hippocampal dysfunction. This study examines how a single disorder differentially affects distinct brain regions by using human patient iPSC-derived cortical- and hippocampal-ganglionic eminence assembloids to model Developmental and Epileptic Encephalopathy 13 (DEE-13), a condition arising from gain-of-function mutations in the SCN8A gene. While cortical assembloids showed network hyperexcitability akin to epileptogenic tissue, hippocampal assembloids did not, and instead displayed network dysregulation patterns similar to in vivo hippocampal recordings from epilepsy patients. Predictive computational modeling, immunohistochemistry, and single-nucleus RNA sequencing revealed changes in excitatory and inhibitory neuron organization that were specific to hippocampal assembloids. These findings highlight the unique impacts of a single pathogenic variant across brain regions and establish hippocampal assembloids as a platform for studying neurodevelopmental disorders.

Behavioural and Electrophysiological Features of WAG/Rij Rats with Different Forms of Genetic Epilepsy

Behavioural and Electrophysiological Features of WAG/Rij Rats with Different Forms of Genetic Epilepsy

Pharmacological chaperones restore proteostasis of epilepsy-associated GABAA receptor variants

Recent advances in genetic diagnosis identified variants in genes encoding GABAA receptors as causative for genetic epilepsy. Here, we selected eight disease-associated variants in the α1 subunit of GABAA receptors causing mild to severe clinical phenotypes and showed that they are loss of function, mainly by reducing the folding and surface trafficking of the α1 protein. Furthermore, we sought client protein-specific pharmacological chaperones to restore the function of pathogenic receptors. Applications of positive allosteric modulators, including Hispidulin and TP003, increase the functional surface expression of the α1 variants. Mechanism of action study demonstrated that they enhance the folding, assembly, and trafficking and reduce the degradation of GABAA variants without activating the unfolded protein response in HEK293T cells and human iPSC-derived neurons. Since these compounds cross the blood-brain barrier, such a pharmacological chaperoning strategy holds great promise to treat genetic epilepsy in a GABAA receptor-specific manner.