Wirrell, Elaine

Abstract Objectives Dravet syndrome (DS) is a drug‐resistant developmental and epileptic encephalopathy, often requiring three or more antiseizure medications (ASMs). Consequently, the therapeutic landscape is highly complex, combining DS‐specific agents (stiripentol, STP; cannabidiol, CBD; fenfluramine, FFA), non‐specific ASMs, and non‐pharmacologic options such as dietary therapy or neuromodulation. In addition, recognition of patients' changing needs across the lifespan, together with the essential contribution of caregiver education to effective treatment oversight—including awareness of potential drug–drug interactions and adverse events—emphasizes the value of an integrated and forward‐looking approach. A consensus initiative was developed to guide clinicians in the management of patients with DS, with a particular focus on STP‐containing regimens. Methods Based on a literature review and clinical vignette discussions, a nominal group of five international DS experts developed 38 statements across six themes: (i) general principles, (ii) guiding physicians to empower families, (iii) STP as add‐on to specific and non‐specific Dravet ASMs, (iv) FFA in regimens containing STP, (v) CBD in regimens containing STP, and (vi) patient follow‐up during treatment initiation. Statements were scored on a 9‐point Likert scale (1 = strongly disagree, 9 = strongly agree) first by the nominal group and then by an international panel of 59 DS clinicians. Consensus was defined as ≥75% rating ≥7 and/or a median ≥8. Results Thirty‐four of the 38 statements (89%) reached consensus among both the nominal group and the international panel; one did not reach consensus in either, and three reached consensus only among the nominal group. Both panels agreed on the importance of involving families in treatment decisions and follow‐up, as well as on key aspects of polytherapy management, including ASM initiation, treatment adjustments, and adverse event management. Significance This international consensus integrates evidence and clinical expertise to establish shared principles that address a long‐standing gap in the polytherapeutic management of Dravet syndrome. Plain Language Summary Dravet syndrome is a rare and severe form of epilepsy that begins in early childhood, with seizures that often persist throughout life. Because the disease is highly drug resistant, most patients are treated with polytherapy, making clinical management complex for clinicians. This consensus brings together published evidence and expert experience to provide practical guidance on the management of polytherapy in Dravet syndrome, supporting clinicians in optimizing patient care.

Abstract Background Genetic testing is increasingly used in presurgical evaluation, but the yield of resection across germline genetic epilepsies remains uncertain. Methods We conducted a systematic review of MEDLINE (PubMed) and Scopus and added cases from three institutional cohorts and the Pediatric Epilepsy Research Consortium (PERC) databases, including individuals with pathogenic/likely pathogenic germline variants besides tuberous sclerosis and neurofibromatosis who underwent resection or laser ablation. Etiologies were grouped into biologically informed categories (GATORopathies, vascular, overgrowth, CNVs, channelopathies, synaptopathies, other). Primary outcome was seizure freedom (Engel I) at last follow-up. Group comparisons used Fisher’s exact and Kruskal–Wallis tests (α=0.05; Bonferroni when applicable). Prespecified sensitivity analyses stratified by lesional status, excluded GATORopathies, and restricted to literature-only cases. Results We included 223 literature cases (64 studies), 35 institutional cases, and 11 PERC cases (n=269). Median follow-up was 24 months (IQR 12–48.0). Seizure freedom was achieved in: vascular disorders 14/19 (73.6%), GATORopathies 79/120 (67.5%), CNVs 18/31 (66.7%), overgrowth 7/13 (53.8%), other 16/25 (41.7%), channelopathies 13/43 (33.3%), and synaptopathies 4/18 (22.2%) (overall p<0.001). Among cases with known imaging, 208/253 (82.2%) had epileptogenic MRI lesions, including 64% of channelopathies and 80% of the synaptopathies. In univariate contrasts (each category vs all others), odds of seizure freedom were higher for vascular disorders (2.66-fold, 95% CI 0.87–9.72) and GATORopathies (2.46-fold, 95% CI 1.46–4.18), and lower for synaptopathies (∼4.2-fold lower, OR 0.24, 95% CI 0.05– 0.78) and channelopathies (∼4.5-fold lower, OR 0.22, 95% CI 0.09–0.48). Direction and magnitude were consistent across prespecified sensitivity analyses (lesional-only, literature-only, exclusion of GATORopathies). Conclusions Resective surgeries can be effective in germline genetic epilepsies, but outcomes vary by pathway. Disorders with discrete, lesional substrates (GATORopathies, vascular) show the highest likelihood of seizure freedom, whereas channelopathies and synaptopathies, despite the presence of MRI lesions, have substantially lower yields even in lesional cases. Prospective, genotype-aware surgical registries with standardized reporting (EEG, imaging, pathology) and time-to-event outcomes are needed to refine the selection of surgical candidates and quantify seizure and non-seizure-related outcomes.

Abstract Objective Dravet syndrome (DS) is the prototypic developmental and epileptic encephalopathy, characterized by drug‐resistant seizures, developmental slowing, and many other morbidities. Detailed characterization of behavioral phenotypes and social–emotional skill development are limited. Methods We prospectively assessed behavioral and social–emotional problems in the ENVISION natural history study (NCT04537832) of children with DS associated with SCN1A pathogenic variants ( SCN1A + DS) enrolled at <5 years of age. Assessments every 3 months for up to 2 years included the Child Behavior Checklist (CBCL), Strengths and Difficulties Questionnaire (SDQ), Brief Infant‐Toddler Social and Emotional Assessment (BITSEA), and Vineland Adaptive Behavior Scales, 3rd Edition (VABS‐3). Results Fifty‐eight children with DS enrolled at 16 sites worldwide. Problematic behaviors—inattention, aggressive or oppositional behaviors, and withdrawn and autistic behaviors—began before age 3 years, became more evident with age, and were clinically significant in many children by age 3–4 years. CBCL Total, Externalizing, and Internalizing Problems T‐scores rose by approximately 3 points per year, and BITSEA Problem scale scores increased by 2.3 points annually ( p = .002). SDQ Hyperactivity scores worsened over time ( p = .013), whereas emotional difficulties remained stable. VABS‐3 Socialization domain scores, which were already more than 1 SD below the normative mean at baseline, decreased further, particularly in younger participants. Correlation analyses showed that poorer communication abilities were associated with increased problematic behaviors ( R = −.55 for CBCL Total Problems and VABS‐3 Communication scores). Mixed‐effects modeling identified age as the strongest predictor of worsening behavioral outcomes. Significance We found that behavioral and social–emotional problems are inherent components of DS that present in toddlerhood and worsen throughout early childhood. This highlights the need to diagnose and manage these issues early. Targeted therapy may alleviate the wide‐ranging morbidities that are intrinsic to DS, including the social–emotional and behavior problems that frequently emerge.

Abstract Objective Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy with a high seizure burden and mortality risk. Stiripentol, one of the first DS‐specific therapies, received FDA approval in 2018 but its real‐world use and impact post‐approval in the USA remain insufficiently characterized. The STIRUS study aimed to assess treatment patterns, clinical efficacy, and quality of life outcomes associated with stiripentol in a contemporary US cohort. Methods STIRUS was a retrospective, multicenter chart review of 98 DS patients who initiated stiripentol after FDA approval and were treated for at least 3 months. Data were collected from 10 USA epilepsy centers on seizure types and frequency, status epilepticus (SE), rescue medication use, emergency room visits, and quality of life, at baseline and during the first and final 3 months on stiripentol. Changes over time were assessed using generalized estimating equation models. Results Initiation of stiripentol was associated with a significant reduction in bilateral convulsive seizure frequency (OR = 2.16, p < 0.006) and a nearly 50% decrease in SE episodes (OR = 2.9, p < 0.003). Importantly, there was a marked decline in rescue medication use and seizure‐related hospital visits: the proportion of patients requiring no rescue medications increased from 23% to over 53%, and those needing frequent emergency interventions dropped from 39% at baseline to 14% during the final 3 months. Quality of life improved in more than half of patients and caregivers. Significance The STIRUS study supports the real‐world efficacy of stiripentol in reducing seizure burden and healthcare utilization in DS. Despite its demonstrated benefits and approval for use in infants, stiripentol remains underutilized and often introduced late in the treatment course. Early and broader adoption may help improve clinical outcomes and quality of life in this vulnerable population. Plain Language Summary The STIRUS study found that stiripentol, an anti‐seizure medication specifically approved for Dravet Syndrome, helped reduce seizures and hospital visits for children living with this severe form of epilepsy. Patients had fewer convulsive seizures, needed fewer rescue medicines, and reported better quality of life. Despite these benefits, stiripentol is still not widely used and often started too late in treatment, suggesting earlier use could further improve outcomes.

Abstract Objective Dravet syndrome (DS) is a developmental and epileptic encephalopathy characterized by drug‐resistant seizures and developmental slowing. Although cognitive and executive function deficits have been described, their early trajectory is not well understood. Methods The prospective ENVISION natural history study (NCT04537832) assessed cognitive, executive, and adaptive function in children younger than 5 years of age with SCN1A + DS every 6 months for up to 2 years using Bayley Scales of Infant and Toddler Development, 3rd Edition (BSID‐III), Wechsler Preschool & Primary Scale of Intelligence, 4th Edition (WPPSI‐IV), Vineland Adaptive Behavior Scales, 3rd Edition (VABS‐3), Behavior Rating Inventory of Executive Function – Preschool Version (BRIEF‐P), and Pediatric Evaluation of Disability Inventory (PEDI). Results Fifty‐eight children were enrolled, with 47% younger than age 2 years. At least 80% of children did not achieve age‐appropriate milestones. Mean BSID‐III Cognitive raw scores increased minimally, with age‐equivalent gains of only 3 months over 1.5 years. Mean Cognitive Composite scores declined significantly by Month 12 (from 81.6 to 72.2; change: –11.0, 95% confidence interval [CI]: −15.3 to −6.8), signaling a widening gap compared with neurotypical development. Executive function worsened, with mean BRIEF‐P Global Executive Composite T‐scores increasing by 3.2 points/year. For some participants, scores were 5 standard deviations (SD) above the normative mean, reflecting abilities profoundly below age expectations (bottom .00003% of the population). Adaptive functioning worsened, with mean VABS‐3 Adaptive Behavior Composite decreasing from 78.7 to 68.1 over 1.5 years (change: –9.0, 95% CI: −11.9 to −6.1) and greater decline among children <2 years at enrollment, with scores decreasing by ~15 points (1 SD). Over half of children >3 years could not remove clothing independently; and when placed on a toilet, 48% could not use it. Significance Infants and young children with SCN1A + DS show significant and progressive developmental slowing across several domains, highlighting urgent need for therapies to mitigate the devastating impact on individuals and families.

Abstract This paper provides a practical guide to applying the updated seizure classification in clinical settings. The updated classification, published by the International League Against Epilepsy in 2025, builds on the operational classification introduced in 2017. It aims to enhance clarity, clinical relevance, and consistency in seizure terminology across various healthcare settings. The classification system distinguishes between four main seizure classes: focal, generalized, unknown whether focal or generalized, and unclassified. The basic version allows for application even in resource‐limited or primary care environments, while the expanded version offers detailed semiological descriptors and supports advanced diagnostic and surgical decision‐making. Consciousness, defined through awareness (recall) and responsiveness, is now considered a classifier. The paper also highlights the importance of distinguishing observable from non‐observable features and integrates semiology into the expanded classification with attention to temporal sequence and somatotopic detail. Generalized seizures are categorized into seizure types having a direct impact on syndrome diagnosis and treatment decisions. Epileptic spasms are given special attention because of their unique presentation and the urgency of early intervention, particularly in infants. To support clinical implementation, this paper includes a comprehensive table of semiological descriptors, definitions of generalized seizure types, and a series of real‐world case vignettes illustrating the application of the updated seizure classification. Supplementary figures and videos further support the educational aims of the paper. This practical guide is intended for healthcare professionals managing patients with epilepsy, providing a clear, structured approach to seizure classification that is adaptable to varying levels of clinical expertise and diagnostic resources.