Intellectual functioning and behavior in Dravet syndrome: A systematic review

The multidimensional impact of Dravet syndrome on caregivers: A comprehensive review

BACKGROUND

Dravet syndrome (DS) is a rare developmental and epileptic encephalopathy that places a substantial burden on both affected individuals and their informal caregivers. The aim of this review is to examine the multifaceted impact of DS on informal caregivers, focusing on key factors that contribute to their challenges and overall burden.

METHODS

The PRISMA guidelines were followed and a comprehensive search of electronic databases (PubMed, Science Direct, Taylor & Francis) was conducted to identify original research articles from January 2015 till the end of December 2024 in English language. Two reviewers independently carried out the screening. The quality of studies was assessed using the AXIS Critical Appraisal Tool for Cross-Sectional Studies. Relevant data was extracted and a narrative synthesis was performed to integrate the findings.

RESULTS

The review included ten studies involving 887 caregivers of patients with DS. Most studies reported a higher proportion of female caregivers. Additionally, all studies were conducted in Europe and the USA. Patient-related characteristics, caregiver characteristics, psychological and physical strain, family functioning, access to support system, financial burden, and difficulties in balancing caregiving responsibilities and personal needs were found to influence caregivers' experiences and overall well-being. Women, especially mothers, were found to face greater psychological and physical burden, along with productivity loss and difficulties in managing caregiving and personal responsibilities.

CONCLUSION

Caregivers of individuals with DS face significant challenges. More research is needed to understand the full impact of DS on caregivers. Targeted interventions and improved resources are essential to reduce strain and improve care for both caregivers and individuals with DS.

Perception of psychosocial burden in mothers of children with rare pediatric neurological diseases

Parenting a child with rare paediatric neurological diseases (RPNDs) severely affects parents' quality of life and the caregiver burden. Since mothers tend to be the primary caregivers more often, this study focuses on previously unexplored experiences of mothers of four RPNDs: 22q11.2 deletion syndrome (22q11.2DS), Angelman syndrome (AS), Dravet syndrome (DS) and Williams syndrome (WS). A cross-sectional survey of 302 mothers revealed that, while caring for RPND children seriously impacts well-being and stress in all mothers, there also exist some significant differences in diagnostic experiences, quality of life and the caregiver burden across conditions. DS and AS mothers reported difficulties in the access to and reimbursement for modern genetic testing and psychological support. DS and WS mothers were concerned over the impact of the delayed diagnosis on unnecessary hospitalisations and medication in their children. 22q11.2DS mothers felt more supported than others. While DS and AS mothers reported a greater burden in caregiving and reduced quality of life, WS mothers reported significantly lower burdens and higher scores across all quality-of-life domains. Mothers' financial well-being, employment status and early diagnosis significantly influenced their experiences. These findings underscore the need for tailored support for RPND mothers, with a focus on early diagnosis and financial and psychological help.

Treatment of Seizures in People with Intellectual Disability

There is a synergistic relationship between epilepsy and intellectual disability (ID), and the approach to managing people with these conditions needs to be holistic. Epilepsy is the main co-morbidity associated with ID, and clinical presentation tends to be complex, associated with higher rates of treatment resistance, multi-morbidity and premature mortality. Despite this relationship, there is limited level 1 evidence to inform treatment choice for this vulnerable population. This review updates the current evidence base for anti-seizure medication (ASM) prescribing for people with ID. Recommendations are made on the basis of evidence and expert clinical opinion and summarised into a Traffic Light System for accessibility. This review builds on work developed through UK's Royal College of Psychiatrists, Faculty of Intellectual Disability Psychiatry and includes newer pragmatic data from the Cornwall UK Ep-ID Research Register, a national research register for England and Wales that has been in existence for the last 10 years. The Register acts as a source for an in-depth exploration of the evidence base for prescribing 'newer' (third generation, specifically post-2004) ASMs. Its findings are discussed and compared. A practical approach to prescribing and choosing ASMs is recommended on the based evidence. This approach considers the drug profile, including adverse effects and clinical characteristics. The review also details newer specialist ASMs restricted to certain epilepsy syndromes, and potential future ASMs that may be available soon. For completeness, we also explore non-pharmacological interventions, including surgeries, to support epilepsy management.

Autism and attention-deficit/hyperactivity disorder in children with Dravet syndrome: A population-based study

AIM

To identify on a population basis the prevalence of autism and attention-deficit/hyperactivity disorder (ADHD) in children with Dravet syndrome and factors associated with symptoms of autism and ADHD.

METHOD

Forty-one of 48 children with Dravet syndrome living in Sweden, born between 1st January 2000 and 31st December 2018 underwent assessment including measures of autism and ADHD. Diagnoses of autism and ADHD were made with respect to DSM-5 criteria. Factors associated with features of autism and ADHD were analysed via regression.

RESULTS

Twenty-five of the 41 children fulfilled DSM-5 criteria for autism spectrum disorder and 12 of 37 children considered for an ADHD diagnosis fulfilled DSM-5 criteria for ADHD. Severe intellectual disability was significantly associated with a greater degree of autistic features (p < 0.001) and a DSM-5 diagnosis of autism spectrum disorder (p = 0.029). Younger children had significantly more features of ADHD (p = 0.004) and features of inattention were significantly more common than features of hyperactivity/impulsivity (p < 0.001).

INTERPRETATION

Children with Dravet syndrome often have significant features of autism and ADHD, primarily inattentive type. Screening for autism and ADHD should be routine in children with Dravet syndrome.

WHAT THIS PAPER ADDS

In total, 25 of 41 assessed children with Dravet syndrome fulfilled DSM-5 criteria for autism. Twelve of 37 assessed children with Dravet Syndrome met DSM-5 criteria for attention-deficit/hyperactivity disorder (ADHD). Severe intellectual disability was significantly associated with a greater degree of autism spectrum disorder features. Younger children had significantly more features of ADHD.

Health-related quality of life, depression, anxiety, and sleep in mothers and fathers of children with dravet syndrome in Sweden

PURPOSE

To evaluate health-relatedquality of life(HRQoL), depression, anxiety and sleep in caregivers (mothers and fathers) of children with Dravet Syndrome (DS).

METHODS

Mothers (n = 41) and fathers (n = 39) of 42 children with DS completed the Rand 36-Item Short Form Health Survey (SF-36), the Hospital Anxiety and Depression Scale(HADS), and the Insomnia Severity Index (ISI). Mothers' and fathers' SF-36 scores were compared with Swedish population values for males and females using t-tests. Differences in proportions of mothers vs. fathers classified as 'noncases' or 'possible/probable' cases of anxiety (HADS-A) and depression (HADS-D), respectively, were assessed with the chi-square test. Parents' SF-36, HADS symptom and ISI scores were compared using t-tests. Linear regression analysis was employed to explore factors associated with sleep and mental health.

RESULTS

Mothers had significantly lower scores compared with population norms on seven of eight SF-36 domains whilst fathers had lower scores on five domains. Mothers had significantly lower scores than fathers on one (i.e. Role limitation - emotional) SF-36 domain. A larger proportion of mothers than fathers had 'possible/probable' anxiety (83 % vs 59 %; p = 0.018), but not depression (46 % vs. 46 %; p = 0.987). Mothers reported more symptoms of anxiety than fathers (p = 0.007) but there was no difference in depression (p = 0.399). Mothers (78 %) reported more sleep difficulties than fathers (67 %) but the difference was not significant (p = 0.254). Sleep difficulties were predicted by mental health difficulties and vice versa, in mothers and fathers (all p < 0.001). Increased child sleep difficulties were associated with increased maternal sleep difficulties (p = 0.003) but not paternal sleep difficulties.

CONCLUSION

Parents of children with DS have high levels of mental health and sleep difficulties and reduced HRQoL. Mothers experienced higher levels of anxiety, but not depression, than fathers. There is a need to screen parents of children for these difficulties and develop interventions to ameliorate the difficulties.

Early developmental alterations of CA1 pyramidal cells in Dravet syndrome

Dravet Syndrome (DS) is most often caused by heterozygous loss-of-function mutations in the voltage-gated sodium channel gene SCN1A (Nav1.1), resulting in severe epilepsy and neurodevelopmental impairment thought to be cause by reduced interneuron excitability. However, recent studies in mouse models suggest that interneuron dysfunction alone does not completely explain all the cellular and network impairments seen in DS. Here, we investigated the development of the intrinsic, synaptic, and network properties of CA1 pyramidal cells in a DS model prior to the appearance of overt seizures. We report that CA1 pyramidal cell development is altered by heterozygous reduction of Scn1a, and propose that this is explained by a period of reduced intrinsic excitability in early postnatal life, during which Scn1a is normally expressed in hippocampal pyramidal cells. We also use a novel ex vivo model of homeostatic plasticity to show an instability in homeostatic response during DS epileptogenesis. This study provides evidence for the early effects of Scn1a haploinsufficiency in pyramidal cells in contributing to the pathophysiology of DS.

Survey of rehabilitation approaches and plans for individuals with dravet syndrome (RAPIDS) in Italy: Current practices and strategies to progress

Dravet syndrome, a developmental and epileptic encephalopathy, manifests with varying degrees of cognitive and communication impairment, postural and movement disorders (such as ataxia, coordination issues, and crouch gait) and behavioural challenges (including attention deficit/hyperactivity, oppositional/defiant behaviour, and autistic traits). Rehabilitation is a valuable tool for most patients, typically prescribed to address the most pressing issues. However, current practices often fall short in proactively preventing and treating known challenges associated with the syndrome, as indicated by the latest literature, at different life stages. Furthermore, there is a notable lack of evidence regarding treatment types and efficacy specific to people with Dravet Syndrome. Conducted in collaboration with one of the Italian Patient associations, this national survey provides a comprehensive view of the rehabilitation landscape in Dravet Syndrome, as perceived by caregivers. It outlines the types of treatments for 51 patients, based on age and relevant clinical features. The findings reveal a heterogenous rehabilitation approach, only partly tailored to the presence of specific comorbidities, and underline numerous unmet needs. Compared to the past there is indirect evidence that more patients are offered early rehabilitation. Nonetheless, while nowadays speech therapy and neuropsychomotor therapy are nearly universal for children up to the age of 10, some begin physiotherapy and psychotherapy thereafter, with a majority discontinuing treatments. Therefore, families of adolescent and adult patients often face a lack of comprehensive support, predominantly offered when epilepsy is more challenging to control affecting rehabilitation adherence and effectiveness. Finally, a negligible minority is offered treatments such as neurovisual training, augmentative and alternative communication, and occupational therapy. Many of these considerations could apply to other developmental and epileptic encephalopathy with lifelong disability. This survey calls for more data collection on this important topic for more efficient allocation of rehabilitation resources.

Identification of etiologies according to baseline clinical features of pediatric new-onset refractory status epilepticus in single center retrospective study

PURPOSE

New-onset refractory status epilepticus (NORSE) is defined as a state of prolonged seizure activity that does not improve despite the appropriate administration of medications, with underlying causes unknown after the initial diagnosis of status epilepticus. Because episodes of NORSE are accompanied by severe complications and a high risk of mortality, the prompt identification of the underlying cause is crucial for effective treatment and outcome prediction. This study assessed the relationship of NORSE etiologies with baseline clinical features in pediatric population.

METHODS

Seventy-one pediatric patients, under 18 years of age at the initial diagnosis (4.50 ± 4.04, mean ± standard deviation), who experienced at least one episode of NORSE and underwent a comprehensive diagnostic evaluation between January 2005 and June 2020 at our center, were retrospectively selected. We reviewed clinical features at disease onset and long-term follow-up data. Uniform manifold approximation and projection (UMAP) was used to distinguish etiological clusters according to baseline clinical characteristics, and further analysis was performed based on underlying etiologies.

RESULTS

Two distinct etiological groups-genetic and non-genetic-were identified based on the UMAP of clinical characteristics. Dravet syndrome (12/15, 80%) was more predominant in patients with a genetic diagnosis, whereas cryptogenic NORSE and encephalitis were prevalent in patients without a genetic diagnosis. The analysis of etiological categories revealed that age at the onset of status epilepticus (P=0.021) and progression to super refractory status epilepticus (SRSE) (P=0.038) were independently associated with differences in etiologies.

CONCLUSION

Several clinical features in patients with NORSE, including the age of onset and the development of SRSE, can help identify underlying causes, which necessitate prompt and adequate treatment.

Caregiver perceptions of the impact of Dravet syndrome on the family, current supports and hopes and fears for the future: A qualitative study

BACKGROUND

Dravet syndrome (DS) is a Developmental and Epileptic Encephalopathy (DEE) with onset typically in infancy. Seizures are pharmaco-resistant, and neurodevelopment is compromised in almost all children. There is limited data on the impact of the condition on the family, support needs and hopes and fears in Sweden.

METHODS

Interviews were undertaken with the caregivers of 36 of 48 (75%) living children with DS in Sweden focusing on the perceived impact on the family, current supports and hopes and fears for the future. Data from the interviews were analyzed by two raters using reflexive thematic analysis.

RESULTS

The analysis revealed seven main themes focusing on the perceived negative impact the disease has on caregivers and family functioning. These negative impacts concerned: caregiver sleep (e.g., frequent night waking), siblings (e.g., gets less attention/time), social life (e.g., limited vacations), family finances (e.g., limited career progression), parental health (both mental and physical) and need for constant supervision (e.g., child's need for constant supervision for fear of seizures). Another theme concerned the impact on family relationships. Whilst some caregivers perceived the impact to be negative (e.g., limited time for each other) others felt that having a child with DS lead to stronger relationships and more 'teamwork'. With respect to supports, the caregivers identified a number of areas where they felt the family could access appropriate supports. Themes regarding supports included: support from the wider family and friends, support from DS support groups (online or in-person), support from the child's hospital or disability service and respite care (e.g., child was looked after on weekends or had paid carers in the home). Regarding hopes and fears for the future, responses focused mainly on fears, including concerns about premature death of the child, transition to adult healthcare services and care arrangements for child when parents are dead. Hopes for the future included better treatment for epilepsy and associated neurodevelopmental problems and finding a cure for DS.

CONCLUSIONS

Caregivers of children with DS report that the disease can have a very comprehensive negative impact on caregiver and family functioning. Identifying and providing the supports to ameliorate these negative impacts is vital to optimize caregiver and family wellbeing and quality of life.

SCN1A-Characterization of the Gene's Variants in the Polish Cohort of Patients with Dravet Syndrome: One Center Experience

The aim of this study was to characterize the genotype and phenotype heterogeneity of patients with SCN1A gene mutations in the Polish population, fulfilling the criteria for the diagnosis of Dravet syndrome (DRVT). Particularly important was the analysis of the clinical course, the type of epileptic seizures and the co-occurrence of additional features such as intellectual disability, autism or neurological symptoms such as ataxia or gait disturbances. Based on their results and the available literature, the authors discuss potential predictors for DRVT. Identifying these early symptoms has important clinical significance, affecting the course and disease prognosis. 50 patients of the Pediatric Neurology Clinic of the Institute of Mother and Child in Warsaw clinically diagnosed with DRVT and carriers of SCN1A pathogenic variants were included. Clinical data were retrospectively collected from caregivers and available medical records. Patients in the study group did not differ significantly in parameters such as type of first seizure and typical epileptic seizures from those described in other studies. The age of onset of the first epileptic seizure was 2-9 months. The co-occurrence of intellectual disability was confirmed in 71% of patients and autism in 18%. The study did not show a correlation between genotype and phenotype, considering the severity of the disease course, clinical symptoms, response to treatment, the presence of intellectual disability, autism symptoms or ataxia. From the clinical course, a significant problem was the differentiation between complex febrile convulsions and symptoms of DRVT. The authors suggest that parameters such as the age of the first seizure, less than one year of age, the onset of a seizure up to 72 h after vaccination and the presence of more than two features of complex febrile seizures are more typical of DRVT, which should translate into adequate diagnostic and clinical management. The substantial decrease in the age of genetic verification of the diagnosis, as well as the decline in the use of sodium channel inhibitors, underscores the growing attention of pediatric neurologists in Poland to the diagnosis of DRVT.

Understanding neurodevelopmental trajectories and behavioral profiles in SCN1A-related epilepsy syndromes

BACKGROUND

A pathogenic variant in SCN1A can result in a spectrum of phenotypes, including Dravet syndrome (DS) and genetic epilepsy with febrile seizures plus (GEFS + ) syndrome. Dravet syndrome (DS) is associated with refractory seizures, developmental delay, intellectual disability (ID), motor impairment, and challenging behavior(1,2). GEFS + is a less severe phenotype in which cognition is often normal and seizures are less severe. Challenging behavior largely affects quality of life of patients and their families. This study describes the profile and course of the behavioral phenotype in patients with SCN1A-related epilepsy syndromes, explores correlations between behavioral difficulties and potential risk factors.

METHODS

Data were collected from questionnaires, medical records, and semi-structured interviews. Behavior difficulties were measured using the Adult/Child Behavior Checklist (C/ABCL) and Adult self-report (ASR). Other questionnaires included the Pediatric Quality of Life Inventory (PedsQL), the Functional Mobility Scale (FMS) and the Sleep Behavior Questionnaire by Simonds & Parraga (SQ-SP). To determine differences in behavioral difficulties longitudinally, paired T-tests were used. Pearson correlation and Spearman rank test were used in correlation analyses and multivariable regression analyses were employed to identify potential risk factors.

RESULTS

A cohort of 147 participants, including 107 participants with DS and 40 with genetic epilepsy with febrile seizures plus (GEFS + ), was evaluated. Forty-six DS participants (43.0 %) and three GEFS + participants (7.5 %) showed behavioral problems in the clinical range on the A/CBCL total problems scale. The behavioral profile in DS exists out of withdrawn behavior, aggressive behavior, and attention problems. In DS patients, sleep disturbances (β = 1.15, p < 0.001) and a lower age (β = -0.21, p = 0.001) were significantly associated with behavioral difficulties. Between 2015 and 2022, behavioral difficulties significantly decreased with age (t = -2.24, CI = -6.10 - -0.15, p = 0.04) in DS participants aging from adolescence into adulthood. A decrease in intellectual functioning (β = 3.37, p = 0.02) and using less antiseizure medications in 2022 than in 2015, (β = -1.96, p = 0.04), were identified as possible risk factors for developing (more) behavioral difficulties.

CONCLUSIONS

These findings suggest that, in addition to epilepsy, behavioral difficulties are a core feature of the DS phenotype. Behavioral problems require personalized management and treatment strategies. Further research is needed to identify effective interventions.

Diagnosis, epilepsy treatment and supports for neurodevelopment in children with Dravet Syndrome: Caregiver reported experiences and needs

BACKGROUND

Dravet syndrome is a rare infantile onset epilepsy syndrome encompassing treatment resistant epilepsy and neurodevelopmental difficulties. There is limited data regarding caregiver experiences of diagnosis, treatment and supports for the associated neurodevelopmental problems.

METHOD

Semi-structured interviews were conducted with caregivers of 36/48 children (75% of total population in Sweden) with Dravet syndrome. Data was analysed using thematic analysis.

RESULTS

Regarding the diagnostic experience, themes were: Delays in diagnostic process, genetic testing not optimal, communication of Dravet syndrome diagnosis and support and information soon after diagnosis. Caregivers felt that delays in diagnosis and testing could have been avoided whilst experiences of communication of diagnosis and support after diagnosis varied. In terms of treatment for seizures, the themes were: Satisfied with treatment, emergency treatment, treatment with antiseizure medications, strategies to control seizures via temperature regulation/avoidance of infections and use of equipment and aids. Caregivers were in the main accepting that seizures in Dravet syndrome are very difficult to treat and that seizure freedom is often an unachievable goal. Many felt frustrated that they were expected to take responsibility with respect to choice of medication. They often employed strategies (e.g., avoidance of physical activity) to reduce seizures or their impact. In terms of supports for neurodevelopmental problems, the themes were: Struggled to access support, lack of integrated healthcare and satisfaction with school. Many caregivers felt that accessing necessary supports for their children and developmental and behavioural needs was a struggle and that the provision of support often lacked integration e.g., lack of collaboration between child's disability service and school. Caregivers also expressed a desire that there would be better knowledge of Dravet syndrome in emergency departments and schools, that care would be better integrated and that there would be more supports for assessment and interventions regarding the associated neurodevelopmental problems.

CONCLUSION

The responses of caregivers of children with Dravet syndrome highlight the need for supports from diagnosis for both epilepsy and neurodevelopmental problems. Good examples of provision were identified but parents often felt they lacked support and support often came from providers who lacked knowledge of the syndrome. Collaboration between medical, disability and school services was often lacking.

Adaptive functioning and neurodevelopment in patients with Dravet syndrome: 12-month interim analysis of the BUTTERFLY observational study

OBJECTIVE

The BUTTERFLY observational study aims to elucidate the natural trajectory of Dravet syndrome (DS) and associated comorbidities in order to establish a baseline for clinical therapies. We present the 12-month interim analysis of the study.

MATERIALS AND METHODS

Patients with a genetically confirmed diagnosis of DS were enrolled in the study. Adaptive functioning and neurodevelopmental status were measured using the Vineland Adaptive Behavior Scale, Third Edition (Vineland-III), Bayley Scales of Infant Development, Third Edition (BSID-III), and Wechsler Preschool and Primary Scale of Intelligence, Fourth Edition (WPPSI-IV). Executive function, ambulatory function and locomotor activities, and overall clinical status were measured using the Behavior Rating Inventory of Executive Function - Preschool Version (BRIEF-P) scale, Gillette Functional Assessment Questionnaire (Gillette FAQ), and Clinician or Caregiver Global Impression of Change scales (CGI-C or CaGI-C) respectively.

RESULTS

Overall, 36 patients were enrolled across three age groups, with 35 patients completing at least part or all of one post-baseline visit through Month 12. Significant improvements in receptive communication, as assessed by Vineland-III and BSID-III raw scores, and in verbal comprehension subtests, as assessed by WPPSI-IV raw scores, were observed in BUTTERFLY patients for the all-patient group. Many patients performed on the impaired end of the BRIEF-P Global Executive Composite scale at baseline suggesting difficulties in executive function, and no significant change was observed in BRIEF-P scores for the all-patient group. Most patients performed in the dynamic range of the Gillette FAQ at baseline, and no significant change was observed in Gillette FAQ scores for the all-patient group. Lastly, there was significant improvement observed in the CaGI-C scores for the all-patient group.

SIGNIFICANCE

This BUTTERFLY interim analysis shows small improvements in communication skills along with stability in other developmental abilities across patients with DS enrolled in the study from baseline to Month 12.

Long-term predictors of developmental outcome and disease burden in SCN1A-positive Dravet syndrome

Dravet syndrome is a severe infantile onset developmental and epileptic encephalopathy associated with mutations in the sodium channel alpha 1 subunit gene SCN1A. Prospective data on long-term developmental and clinical outcomes are limited; this study seeks to evaluate the clinical course of Dravet syndrome over a 10-year period and identify predictors of developmental outcome. SCN1A mutation-positive Dravet syndrome patients were prospectively followed up in the UK from 2010 to 2020. Caregivers completed structured questionnaires on clinical features and disease burden; the Epilepsy & Learning Disability Quality of Life Questionnaire, the Adaptive Behavioural Assessment System-3 and the Sleep Disturbance Scale for Children. Sixty-eight of 113 caregivers (60%) returned posted questionnaires. Developmental outcome worsened at follow-up (4.45 [SD 0.65], profound cognitive impairment) compared to baseline (2.9 [SD 1.1], moderate cognitive impairment, P < 0.001), whereas epilepsy severity appeared less severe at 10-year follow-up (P = 0.042). Comorbidities were more apparent at 10-year outcome including an increase in autistic features (77% [48/62] versus 30% [17/57], χ2 = 19.9, P < 0.001), behavioural problems (81% [46/57] versus 38% [23/60], χ2 = 14.1, P < 0.001) and motor/mobility problems (80% [51/64] versus 41% [24/59], χ2 = 16.9, P < 0.001). Subgroup analysis demonstrated a more significant rise in comorbidities in younger compared to older patients. Predictors of worse long-term developmental outcome included poorer baseline language ability (P < 0.001), more severe baseline epilepsy severity (P = 0.003) and a worse SCN1A genetic score (P = 0.027). Sudden unexpected death in epilepsy had not been discussed with a medical professional in 35% (24/68) of participants. Over 90% of caregivers reported a negative impact on their own health and career opportunities. Our study identifies important predictors and potential biomarkers of developmental outcome in Dravet syndrome and emphasizes the significant caregiver burden of illness. The negative impact of epilepsy severity at baseline on long-term developmental outcomes highlights the importance of implementing early and focused therapies whilst the potential impact of newer anti-seizure medications requires further study.

Caregiver reported behavior, sleep and quality of life in children with Dravet syndrome: A population-based study

OBJECTIVE

The aim of this population-based study was to assess behavior, sleep, and quality of life, and explore factors associated with these in children with Dravet syndrome.

METHODS

The Developmental Behavior Checklist, the Insomnia Severity Index, and a global question regarding quality of life from the Epilepsy and Learning Disabilities Quality of Life scale were completed by primary caregivers of 42/48 Swedish children with Dravet syndrome, born 2000-2018. Factors associated with problems with insomnia, behavior and quality of life were analyzed using multivariable linear regression.

RESULTS

Scores indicating significant behavioral problems were seen in 29/40 (72 %) children, scores indicating moderate or severe clinical insomnia in 18/42 (43 %) and scores indicating poor or very poor quality of life in 7/41 (17 %). On multivariable analysis, autistic symptoms were significantly associated with behavioral problems (p = 0.013), side-effects of anti-seizure medications (ASMs) were associated with insomnia (p = 0.038), whilst insomnia was significantly associated with poor quality of life (p = 0.016).

SIGNIFICANCE

Dravet syndrome in children is associated with significant problems with behavior, sleep and quality of life. There is a need to optimize treatment via ASMs and develop and evaluate interventions to treat behavioral and sleep difficulties to optimize outcomes.

Severe behavior problems in SYNGAP1-related disorder: A summary of 11 consecutive patients in a tertiary care specialty clinic

SYNGAP1-related disorder (SYNGAP1-RD) is a neurodevelopmental disorder that is commonly associated with epilepsy, autism spectrum disorder (ASD), and disruptive behaviors. In this study, behavior problems in 11 consecutive patients with SYNGAP1-RD are described and quantified based on a behavioral screening conducted within the context of a multi-disciplinary tertiary care specialty clinic visit. The behavioral phenotype was then compared to published samples of behavior problems in ASD and other genetic cause of epilepsy occurring in the context of neurodevelopmental disorders using results from the Aberrant Behavior Checklist-Community (ABC-C), an empirically derived outcome measure. We report common antecedent and consequent events surrounding problem behavior across individuals. Additionally, we report on the management approach of caregivers and the impact of problem behaviors on the family. Our results suggest a number of commonalities between behavioral profiles in SYNGAP1-RD with ASD and other genetic causes of developmental and epileptic encephalopathies, and also highlight severe behavior problems as a specific behavioral phenotype of SYNGAP1-RD.

Unraveling Dravet Syndrome: Exploring the complex effects of sodium channel mutations on neuronal networks

Dravet Syndrome (DS) is a severe developmental epileptic encephalopathy with frequent intractable seizures accompanied by cognitive impairment, often caused by pathogenic variants in SCN1A encoding sodium channel NaV1.1. Recent research utilizing in vitro patient-derived neuronal networks and accompanying in silico models uncovered that not just sodium-but also potassium-and synaptic currents were impaired in DS networks. Here, we explore the implications of these findings for three questions that remain elusive in DS: How do sodium channel impairments result in epilepsy? How can identical variants lead to varying phenotypes? What mechanisms underlie the developmental delay in DS patients? We speculate that impaired potassium currents might be a secondary effect to NaV1.1 mutations and could result in hyperexcitable neurons and epileptic networks. Moreover, we reason that homeostatic plasticity is actively engaged in DS networks, possibly affecting the phenotype and impairing learning and development when driven to extremes.

Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy

Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.

Dravet syndrome: A systematic literature review of the illness burden

We performed a systematic literature review and narrative synthesis according to a pre-registered protocol (Prospero: CRD42022376561) to identify the evidence associated with the burden of illness in Dravet syndrome (DS), a developmental and epileptic encephalopathy characterized by drug-resistant epilepsy with neurocognitive and neurobehavioral impairment. We searched MEDLINE, Embase, and APA PsychInfo, Cochrane's database of systematic reviews, and Epistemonikos from inception to June 2022. Non-interventional studies reporting on epidemiology (incidence, prevalence, and mortality), patient and caregiver health-related quality of life (HRQoL), direct and indirect costs and healthcare resource utilization were eligible. Two reviewers independently carried out the screening. Pre-specified data were extracted and a narrative synthesis was conducted. Overall, 49 studies met the inclusion criteria. The incidence varied from 1:15 400-1:40 900, and the prevalence varied from 1.5 per 100 000 to 6.5 per 100 000. Mortality was reported in 3.7%-20.8% of DS patients, most commonly due to sudden unexpected death in epilepsy and status epilepticus. Patient HRQoL, assessed by caregivers, was lower than in non-DS epilepsy patients; mean scores (0 [worst] to 100/1 [best]) were 62.1 for the Kiddy KINDL/Kid-KINDL, 46.5-54.7 for the PedsQL and 0.42 for the EQ-5D-5L. Caregivers, especially mothers, were severely affected, with impacts on their time, energy, sleep, career, and finances, while siblings were also affected. Symptoms of depression were reported in 47%-70% of caregivers. Mean total direct costs were high across all studies, ranging from $11 048 to $77 914 per patient per year (PPPY), with inpatient admissions being a key cost driver across most studies. Mean costs related to lost productivity were only reported in three publications, ranging from approximately $19 000 to $20 000 PPPY ($17 596 for mothers vs $1564 for fathers). High seizure burden was associated with higher resource utilization, costs and poorer HRQoL. The burden of DS on patients, caregivers, the healthcare system, and society is profound, reflecting the severe nature of the syndrome. Future studies will be able to assess the impact that newly approved therapies have on reducing the burden of DS.

The potential for medicinal cannabis to help manage challenging behaviour in people with intellectual disability: A perspective review

BACKGROUND

Around 2% of the population have intellectual disabilities. Over one-third people with intellectual disabilities (PwID) present with 'challenging behaviour', which nosologically and diagnostically is an abstract concept. Challenging behaviour is influenced by a range of bio-psycho-social factors in a population, which is unable to suitably comprehend and/or communicate concerns. This predisposes to poor health and social outcomes. There is no evidence-based treatments for managing challenging behaviour. Cannabidiol (CBD) and tetrahydrocannabinol (THC) are being trialled for a range of disorders, which are over-represented in PwID and provoke challenging behaviours, such as severe epilepsy, spasticity, post-traumatic stress disorder, social phobia, pain, etc.

METHODS

This perspective review explores the different conditions, which benefit from medicinal CBD/THC preparations, by analysing recent literature from neurobiological, pre-clinical and clinical studies related to the topic. The evidence is synthesised to build an argument of the therapeutic benefits and challenges of medicinal cannabis to manage severe challenging behaviour in PwID.

RESULTS

There is developing evidence of medicinal CBD/THC improving psychiatric and behavioural presentations in general. In particular, there is emergent proof in certain key areas of influence of medicinal CBD/THC positively supporting challenging behaviour, for example in children with neurodevelopmental disorders. However, there are significant challenges in employing such treatments in vulnerable populations such as PwID.

CONCLUSION

Further clinical research for the considered use of medicinal CBD/THC for challenging behaviour management in PwID is needed. Strong co-production with experts with lived experience is needed for further testing to be done in this exciting new area.

Intellectual functioning and adaptive behaviour in children with Dravet syndrome: A population-based study

AIM

To identify, on a population basis, the prevalence of intellectual disability in children with Dravet syndrome, profiles on a measure of adaptive behaviour, and factors associated with intellectual functioning and adaptive behaviour.

METHOD

Forty-two out of 48 children with Dravet syndrome living in Sweden, born between 1st January 2000 and 31st December 2018, underwent assessment of intellectual functioning and adaptive behaviour. Factors associated with level of intellectual functioning and adaptive behaviour were analysed.

RESULTS

Eight-six per cent (n = 36) of the children fulfilled DSM-5 criteria for intellectual disability (29% [n = 12] mild intellectual disability, 24% [n = 10] moderate intellectual disability, 33% [n = 14] severe intellectual disability, 0% profound intellectual disability) and 93% (n = 39) had an adaptive behaviour composite more than two standard deviations below the mean. Communication was a significant weakness compared with daily living skills (p < 0.001; mean difference 95% confidence interval [CI] -8.193 to -4.092) and socialization (p = 0.001; mean difference 95% CI 6.511 to -1.775) on the Vineland Adaptive Behavior Scales, Second Edition. The only factors significantly associated with both decreased adaptive behaviour and presence of severe intellectual disability was the presence of increased autistic symptoms and younger age.

INTERPRETATION

Children with Dravet syndrome have a very high level of intellectual disability and almost all have significant deficits in adaptive behaviour. Greater deficits in adaptive behaviour and greater severity of intellectual disability are associated with the presence of increased autistic symptoms, highlighting the need for comprehensive neurodevelopmental assessment for all affected children.

WHAT THIS PAPER ADDS

Eighty-six per cent (n = 36) of children with Dravet syndrome fulfilled criteria for intellectual disability. Ninety-three per cent (n = 39) of children with Dravet syndrome had significant deficits in adaptive behaviour. Communication was a significant weakness on a measure of adaptive behaviour. Increased autistic symptoms were associated with greater deficits in cognition/adaptive behaviour. Older age and earlier status epilepticus were associated with decreased adaptive behaviour.

Emotional experiences of family caregivers of children with Dravet syndrome

BACKGROUND

Since the psychosocial implications of Dravet syndrome (DS) are much more serious and far-reaching than in other types of epilepsy, caring for a DS child seriously affects the entire family. This study describes the emotional experiences of family caregivers of DS children and evaluates the way caregiving affects their perceived quality of life.

METHODS

An anonymous, self-administered online questionnaire was sent to family caregivers of DS children through the online patient advocacy organization the Association for People with Severe Refractory Epilepsy DRAVET.PL. It focussed on the psychosocial impact of caregiving for DS children, the perceived burden of caregiving, caregivers' emotional experiences and feelings related to caregiving, and the impact of DS on the perceived quality of life.

RESULTS

Caregivers stressed that caring for a DS child is associated with a significant psychosocial and emotional burden that affects the entire family. Although most caregivers reported that it was the child's health problems and behavioral and psychological disorders that were the most challenging aspects of caregiving, they were also burdened by the lack of emotional support. As caregivers were profoundly engaged in caregiving, they experienced a variety of distressing emotions, including feelings of helplessness, anxiety and fear, anticipated grief, depression, and impulsivity. Many caregivers also reported that their children's disease disrupted their relationships with their spouses, family, and healthy children. As caregivers reported experiencing role overload, physical fatigue, and mental exhaustion, they stressed the extent to which caregiving for DS children impaired their quality of life, their social and professional life, and was a source of financial burden.

CONCLUSIONS

As this study identified specific burden domains affecting DS caregivers' well-being family carers often need special attention, support, and help. To alleviate the humanistic burden of DS carers a bio-psychosocial approach focusing on physical, mental, and psychosocial interventions should include both DS children and their caregivers.

Fenfluramine treatment for Dravet syndrome: Caregiver- and clinician-reported benefits on the quality of life of patients, caregivers, and families living in Germany, Spain, Italy, and the United Kingdom

OBJECTIVE

Clinical trial data and prior preliminary research indicate that fenfluramine (FFA) provides meaningful improvements in seizure-related and quality of life (QOL) outcomes for individuals with Dravet syndrome (DS), their caregivers, and their families. This study sought to replicate and extend these preliminary findings in a new sample of individuals with DS and their families who live in European countries.

METHODS

Study participants were European clinicians and parents caring for individuals with DS who had participated in an EU FFA Early Access Program. Participants completed one-on-one semi-structured interviews and were asked the extent to which they noticed changes in a number of the child's seizure- and non-seizure-related QOL domains after starting FFA treatment. Participants were also asked about the benefits of FFA treatment to the caregivers' lives and for the family unit.

RESULTS

25 parent caregivers and 16 clinicians participated. The caregivers and clinicians reported improvements in both seizure-related (i.e., reductions in seizure activity, improvements in the frequency or type of seizure triggers and post-ictal recovery times, and improved post-seizure function) and non-seizure-related (e.g., cognition, focus, alertness, speech, academic performance, behavior, sleep, motor function) QOL domains after FFA treatment in individuals with DS. Caregivers also reported improved mood and more time for things they enjoyed, felt less overwhelmed, reported better sleep quality, and had less personal and family stress; clinicians corroborated most of these reports. All clinicians (100%) and most (96%) caregivers said they would "very likely" or "quite likely" recommend FFA to others with DS.

CONCLUSIONS

Real-world experience in Europe with FFA treatment is associated with meaningful improvements in many QOL domains for individuals with DS and their families; replicating findings from a previous study of DS patients and their families from the USA. Caregivers and clinicians provided specific examples of the benefits of FFA for people with DS, caregivers, and their families and are very likely to recommend FFA to others with DS.

Fenfluramine treatment is associated with improvement in everyday executive function in preschool-aged children (<5 years) with Dravet syndrome: A critical period for early neurodevelopment

OBJECTIVE

To evaluate whether fenfluramine (FFA) is associated with improvement in everyday executive function (EF)-self-regulation-in preschool-aged children with Dravet syndrome (DS).

METHODS

Children with DS received placebo or FFA in one of two phase III studies (first study: placebo, FFA 0.2 mg/kg/day, or FFA 0.7 mg/kg/day added to stiripentol-free standard-of-care regimens; second study: placebo or FFA 0.4 mg/kg/day added to stiripentol-inclusive regimens). Everyday EF was evaluated at baseline and Week 14-15 for children aged 2-4 years with parent ratings on the Behavior Rating Inventory of Executive Function®-Preschool (BRIEF®-P); raw scores were transformed to T-scores and summarized in Inhibitory Self-Control Index (ISCI), Flexibility Index (FI), Emergent Metacognition Index (EMI), and Global Executive Composite (GEC). Clinically meaningful improvement and worsening were defined using RCI ≥ 90% and RCI ≥ 80% certainty, respectively. The associations between placebo vs FFA combined (0.2, 0.4, and 0.7 mg/kg/day) or individual treatment groups and the likelihood of clinically meaningful change in BRIEF®-P indexes/composite T-scores were evaluated using Somers'd; pairwise comparisons were calculated by 2-sided Fisher's Exact tests (p ≤ 0.05) and Cramér's V.

RESULTS

Data were analyzed for 61 evaluable children of median age 3 years (placebo, n = 22; FFA 0.2 mg/kg/day, n = 15; 0.4 mg/kg/day [with stiripentol], n = 10; 0.7 mg/kg/day, n = 14 [total FFA, n = 39]). Elevated or problematic T-scores (T ≥ 65) were reported in 55% to 86% of patients at baseline for ISCI, EMI, and GEC, and in ∼33% for FI. Seventeen of the 61 children (28%) showed reliable, clinically meaningful improvement (RCI ≥ 90% certainty) in at least one BRIEF®-P index/composite, including a majority of the children in the FFA 0.7 mg/kg/day group (9/14, 64%). Only 53% of these children (9/17) also experienced clinically meaningful reduction (≥50%) in monthly convulsive seizure frequency, including 6/14 patients in the FFA 0.7 mg/kg/day group. Overall, there were positive associations between the four individual treatment groups and the likelihood of reliable, clinically meaningful improvement in all BRIEF®-P indexes/composite (ISCI, p = 0.001; FI, p = 0.005; EMI, p = 0.040; GEC, p = 0.002). The FFA 0.7 mg/kg/day group showed a greater likelihood of reliable, clinically meaningful improvement than placebo in ISCI (50% vs 5%; p = 0.003), FI (36% vs 0%; p = 0.005), and GEC (36% vs 0%; p = 0.005). For EMI, the FFA 0.7 mg/kg/day group showed a greater likelihood of reliable, clinically meaningful improvement than the FFA 0.2 mg/kg/day group (29% vs 0%; p = 0.040), but did not meet the significance threshold compared with placebo (29% vs 5%; p = 0.064). There were no significant associations between treatment and the likelihood of reliable, clinically meaningful worsening (p > 0.05).

SIGNIFICANCE

In this preschool-aged DS population with high baseline everyday EF impairment, FFA treatment for 14-15 weeks was associated with dose-dependent, clinically meaningful improvements in regulating behavior, emotion, cognition, and overall everyday EF. These clinically meaningful improvements in everyday EF were not entirely due to seizure frequency reduction, suggesting that FFA may have direct effects on everyday EF during the early formative years of neurodevelopment.

Learnings in developmental and epileptic encephalopathies: what do we know?

INTRODUCTION

Developmental and Epileptic Encephalopathies (DEEs) encompass a group of neurological disorders caused by either abnormal neuronal development and white matter maturation or even by weak synaptic plasticity. Hitherto, patients commonly have epileptic seizures featuring cognitive dysfunction, such as neurosensory disorders, difficulties in learning, behavioral disturbances, or speech delay.

AREAS COVERED

This paper provides a comprehensive review of the current knowledge of DEEs and cognition. Medline/Pubmed database was screened for in-English articles published between 1967-2022 dealing with the topic of DEEs and cognitive development. Two authors independently screened the title and abstract of each record and reviewed the selected articles. Reviews, randomized clinical trials, and case reports were selected.

EXPERT OPINION

Scientific literature has never explicitly dealt with the early neuro-psychomotor rehabilitation and neuropsychological assessment of patients with DEEs. Targeted intervention and environmental stimuli can influence the maturation of neuronal circuits and shape changes in physical and mental development based on neuronal plasticity, particularly if applied in 'critical periods' liable to heightened sensitivity. Thus, 'early neurorehabilitation interventions' are worthy of being more and more applied to clinical practice to improve the quality of life and reduce the psychosocial burden on families and caregivers.

Challenging behavior in children and adolescents with Dravet syndrome: Exploring the lived experiences of parents

BACKGROUND

Dravet syndrome (DS) is a monogenic syndrome associated with SCN1A mutations in the majority of patients and characterized by devastating epilepsy, that may be life-threatening. Aside from refractory seizures, core symptoms of DS include behavioral difficulties, developmental delay, cognitive impairment, and motor dysfunction. Previous DS research has mainly focused on epileptic seizures and pharmacological management and less on behavioral difficulties. This study aims to explore the lived experience of parents supporting a child with DS, with a focus on behavioral aspects.

METHODS

We performed a qualitative study using focus groups and following the consolidated criteria for reporting qualitative research (COREQ) guidelines. We organized three focus groups with parents of children and adults with DS and used a pre-defined topic list of open questions, similar for each focus group to ensure comparability. The focus groups were video recorded, transcribed, and anonymized. Data were analyzed using an iterative coding process where codes were sorted into themes. Differences in coding among the researchers were discussed until a consensus was reached.

RESULTS

In total, twenty parents (mothers only) participated in the study. The age of children with DS ranged between 3 to 22 years with a mean age of 11.8 years. A range of behavioral difficulties emerged from the thematic analysis. Overall, the most commonly mentioned behavioral difficulties were aggression, dangerous behavior, impulsivity, hyperactivity, routinized and compulsive habits. Our results showed different behavior per age group, with more externalizing behaviors such as aggression and impulsivity in children aged 3-13 years; and more internalizing behavior such as routinized and compulsive habits in adolescents and young adults (14-22 years). This results in a different kind of support these families need and should be acknowledged when in consult with a healthcare professional. Parents reported that challenging behavior was a source of stress and impacted negatively on their family's quality of life. Parents reported feeling alone in their search for solutions, and many explored options outside the traditional medical context.

CONCLUSION

Our results suggest that the challenging behavior associated with DS leads to a huge burden of care. Healthcare professionals working with DS patients may need to develop shared decision-making strategies that take into account challenging behavior.

Case report: Dravet syndrome, feeding difficulties and gastrostomy

Dravet syndrome (DS) is a developmental and epileptic encephalopathy associated with variants in the voltage-gated sodium channel alpha 1 subunit (SCN1A) gene in around 90% of individuals. The core phenotype is well-recognized, and is characterized by seizure onset in infancy, typically with prolonged febrile seizures, followed by the emergence of multiple seizure types that are frequently drug-resistant, developmental delay, and intellectual disability. Comorbidities are common and include autism spectrum disorder, gait impairment, scoliosis, and sleep disorder. Feeding difficulties and weight loss are frequently reported by DS caregivers, and negatively impact quality of life, yet have received little attention. Here we report an adult with DS who developed reduced food and fluid intake in adolescence, resulting in weight loss and malnutrition. No underlying cause for her feeding difficulties was identified, and she subsequently required insertion of a percutaneous endoscopic gastrostomy. We review the occurrence of feeding difficulties in people with DS and discuss potential mechanisms.

Fenfluramine treatment for dravet syndrome: Real-world benefits on quality of life from the caregiver perspective

OBJECTIVE

Prior research has demonstrated durable and profound reductions in seizure frequency and improvements in executive functions in individuals with Dravet syndrome (DS) who are treated with fenfluramine (FFA). This study aimed to understand the benefits of FFA from the perspective of the patients' caregivers.

METHODS

Caregivers for a child with DS participated in semi-structured interviews to discuss the benefits of FFA treatment on the child with DS, the caregiver, and the family.

RESULTS

65 caregivers participated. Patients were between 2 and 33 years old and had been treated with FFA for an average of 22.7 months. The most commonly reported seizure-related benefits (> 50 % of participants) of FFA treatment included a reduction in seizure activity, fewer seizure triggers, and shorter post-ictal recovery. The most common quality of life (QOL) benefits in patients included improvements in cognitive function, alertness, and academic performance. In addition, the caregivers reported improvements in their sleep quality (74 %) and that they felt less overwhelmed (72 %) and stressed (69 %) after their children began FFA treatment. Many caregivers also reported improved relationships between the child with DS and their siblings (52 %).

CONCLUSIONS

The study found that FFA treatment is associated with meaningful improvement in a large number of QOL domains both for the people with DS who received FFA and their families.

The clinical, economic, and humanistic burden of Dravet syndrome - A systematic literature review

Dravet syndrome (DS) is a developmental and epileptic encephalopathy with evolving disease course as individuals age. In recent years, the treatment landscape of DS has changed considerably, and a comprehensive systematic review of the contemporary literature is lacking. Here we synthesized published evidence on the occurrence of clinical impacts by age, the economic and humanistic (health-related quality-of-life [HRQoL]) burden, and health state utility. We provide an evidence-based, contemporary visualization of the clinical manifestations, highlighting that DS is not limited to seizures; non-seizure manifestations appear early in life and increase over time, contributing significantly to the economic and humanistic burden of disease. The primary drivers of HRQoL in DS include seizure severity, cognition, and motor and behavioral problems; in turn, these directly affect caregivers through the extent of assistance required and consequent impact on activities of daily living. Unsurprisingly, costs are driven by seizure-related events, hospitalizations, and in-home medical care visits. This systematic review highlights a paucity of longitudinal data; most studies meeting inclusion criteria were cross-sectional or had short follow-up. Nonetheless, available data illustrate the substantial impact on individuals, their families, and healthcare systems and establish the need for novel therapies to address the complex spectrum of DS manifestations.

The International Consensus on Diagnosis and Management of Dravet Syndrome

Objective

This study was undertaken to gain consensus from experienced physicians and caregivers regarding optimal diagnosis and management of Dravet syndrome (DS), in the context of recently approved, DS‐specific therapies and emerging disease‐modifying treatments.

Methods

A core working group was convened consisting of six physicians with recognized expertise in DS and two representatives of the Dravet Syndrome Foundation. This core group summarized the current literature (focused on clinical presentation, comorbidities, maintenance and rescue therapies, and evolving disease‐modifying therapies) and nominated the 31‐member expert panel (ensuring international representation), which participated in two rounds of a Delphi process to gain consensus on diagnosis and management of DS.

Results

There was strong consensus that infants 2–15 months old, presenting with either a first prolonged hemiclonic seizure or first convulsive status epilepticus with fever or following vaccination, in the absence of another cause, should undergo genetic testing for DS. Panelists agreed on evolution of specific comorbidities with time, but less agreement was achieved on optimal management. There was also agreement on appropriate first‐ to third‐line maintenance therapies, which included the newly approved agents. Whereas there was agreement for recommendation of disease‐modifying therapies, if they are proven safe and efficacious for seizures and/or reduction of comorbidities, there was less consensus for when these should be started, with caregivers being more conservative than physicians.

Significance

This International DS Consensus, informed by both experienced global caregiver and physician voices, provides a strong overview of the impact of DS, therapeutic goals and optimal management strategies incorporating the recent therapeutic advances in DS, and evolving disease‐modifying therapies.

Up to What Extent Does Dravet Syndrome Benefit From Neurostimulation Techniques?

BACKGROUND

Dravet syndrome (DS) is a refractory developmental and epileptic encephalopathy (EE) with a variety of comorbidities, including cognitive impairment, autism-like behavior, speech dysfunction, and ataxia, which can seriously affect the quality of life of patients and impose a great burden on society and their families. Currently, the pharmacological therapy is patient dependent and may work or not. Neuromodulation techniques, including vagus nerve stimulation (VNS), deep brain stimulation (DBS), transcranial magnetic stimulation (TMS), responsive neurostimulation (RNS), and chronic subthreshold cortical stimulation (CSCS), have become common adjuvant therapies for neurological diseases, but their efficacy in the treatment of DS is unknown.

METHODS

We searched Web of Science, PubMed, and SpringerLink for all published cases related to the neuromodulation techniques of DS until January 15, 2022. The systematic review was supplemented with relevant articles from the references. The results reported by each study were summarized narratively.

RESULTS

The Web of science, PubMed and SpringerLink search yielded 258 items. A total of 16 studies published between 2016 and 2021 met the final inclusion criteria. Overall, 16 articles (109 cases) were included in this study, among which fifteen (107 patients) were involved VNS, and one (2 patients) was involved DBS. After VNS implantation, seizures were reduced to ≥50% in 60 cases (56%), seizure free were found in 8 cases (7.5%). Only two DS patients received DBS treatment, and the initial outcomes of DBS implantation were unsatisfactory. The seizures significantly improved over time for both DBS patients after the addition of antiepileptic drugs.

CONCLUSION

More than half of the DS patients benefited from VNS, and VNS may be effective in the treatment of DS. However, it is important to note that VNS does not guarantee improvement of seizures, and there is a risk of infection and subsequent device failure. Although DBS is a safe and effective strategy for the treatment of refractory epilepsy, the role of DBS in DS needs further study, as the sample size was small. Thus far, there is no strong evidence for the role of DBS in DS.

Motor and behavioral phenotype of Dravet syndrome in adulthood

In a comparative cross-sectional study, 26 adult individuals with clinically typical, genetically confirmed Dravet syndrome (DS) and an equal number of individuals with early onset, problematic epilepsy, and intellectual disability (ID) of comparable severity were included. The aim of the study was to find out whether patients with DS could be clearly distinguished from the comparison group with regard to neurological and behavioral symptoms. Significant differences were found in that individuals with DS clearly more frequently exhibited a symptom cluster characterized by bradykinesia, hypomimia, hypophonia, (spastic) increased muscle tone, ataxia, sthenic perseveration, and a special interest in colors. To these symptoms must be added, according to the findings of previous examinations, mastication, camptocormia/antecollis on the one hand, and the tendency to visual hallucinations on the other hand, in order to define one neuropsychiatric phenotype of DS in adulthood. To these symptoms must be added, according to the findings of previous investigations, crouch gait with camptocormia/antecollis on the one hand, and the tendency to visual hallucinations on the other hand, in order to define one outlined neuropsychiatric phenotype of DS in adulthood.

Psychosocial impact of genetic testing on parents of children with developmental and epileptic encephalopathy

Aim

To investigate the psychosocial impact of genetic testing for childhood‐onset developmental and epileptic encephalopathies (DEEs) in order to identify parents’ information and support needs.

Method

In this mixed‐methods study, we conducted in‐depth semi‐structured interviews with parents (n=25) of children, recruited from the Sydney Children’s Hospital Network, Australia, who had received genetic testing. Thematic saturation was reached; interviews were transcribed, deidentified, line‐by‐line coded, and thematically analysed by three coders, using an inductive approach. We also quantitatively assessed the impact of genetic testing on quality of life outcomes and parents’ satisfaction with genetics services.

Results

Qualitative and quantitative analysis revealed that compassionate genetic counselling and consistent clinician–parent partnerships facilitated parents’ capacity to process their child’s genetic diagnosis. Parents believed that a sparsity of diagnosis‐specific information to contextualize their child’s genetic DEE, combined with limited psychosocial resources to support coping with ongoing prognostic uncertainty, contributed to chronic psychological stress. Access to diagnosis‐specific resources and peer support was considered necessary to support parents in communicating their child’s genetic DEE and to reduce social isolation.

Interpretation

Integrated psychosocial resources, including tailored psychological supports, diagnosis‐specific information, and peer‐to‐peer supports, are priority areas to complement genetic services.

SCN1A Mutation-Beyond Dravet Syndrome: A Systematic Review and Narrative Synthesis

Background: SCN1A is one of the most common epilepsy genes. About 80% of SCN1A gene mutations cause Dravet syndrome (DS), which is a severe and catastrophic epileptic encephalopathy. More than 1,800 mutations have been identified in SCN1A. Although it is known that SCN1A is the main cause of DS and genetic epilepsy with febrile seizures plus (GEFS+), there is a dearth of information on the other related diseases caused by mutations of SCN1A. Objective: The aim of this study is to systematically review the literature associated with SCN1A and other non-DS-related disorders. Methods: We searched PubMed and SCOPUS for all the published cases related to gene mutations of SCN1A until October 20, 2021. The results reported by each study were summarized narratively. Results: The PubMed and SCOPUS search yielded 2,889 items. A total of 453 studies published between 2005 and 2020 met the final inclusion criteria. Overall, 303 studies on DS, 93 on GEFS+, three on Doose syndrome, nine on the epilepsy of infancy with migrating focal seizures (EIMFS), six on the West syndrome, two on the Lennox-Gastaut syndrome (LGS), one on the Rett syndrome, seven on the nonsyndromic epileptic encephalopathy (NEE), 19 on hemiplegia migraine, six on autism spectrum disorder (ASD), two on nonepileptic SCN1A-related sudden deaths, and two on the arthrogryposis multiplex congenital were included. Conclusion: Aside from DS, SCN1A also causes other epileptic encephalopathies, such as GEFS+, Doose syndrome, EIMFS, West syndrome, LGS, Rett syndrome, and NEE. In addition to epilepsy, hemiplegic migraine, ASD, sudden death, and arthrogryposis multiplex congenital can also be caused by mutations of SCN1A.

DRAVET ENGAGE. Parent caregivers of children with Dravet syndrome: Perspectives, needs, and opportunities for clinical research

Dravet syndrome (DS) is an intractable developmental and epileptic encephalopathy significantly impacting affected children and their families. A novel, one-time, adeno-associated virus (AAV)-mediated gene regulation therapy was designed to treat the underlying cause of DS, potentially improving the full spectrum of DS manifestations. To ensure the first-in-human clinical trial addresses meaningful outcomes for patients and families, we examined their perspectives, priorities, goals, and desired outcomes in the design phase through a mixed methods approach (quantitative and qualitative). We conducted a non-identifiable parent caregiver survey, shared through a patient advocacy organization (n = 36 parents; children age ≤6 years). Parents were also engaged via three group discussions (n = 10; children age 2-20 years) and optional follow-up in-depth individual interviews (n = 6). Qualitative data analysis followed an inductive interpretive process, and qualitative researchers conducted a thematic analysis with a narrative approach. Survey results revealed most children (94%) were diagnosed by age 1, with onset of seizures at mean age 6.2 months and other DS manifestations before 2 years. The most desired disease aspects to address with potential new disease-modifying therapies were severe seizures (ranked by 92% of caregivers) and communication issues (development, expressive, receptive; 72-83%). Qualitative results showed the need for trial outcomes that recognize the impact of DS on the whole family. Parents eventually hope for trials including children of all ages and were both excited about the potential positive impact of a one-time disease-modifying therapy and mindful of potential long-term implications. Participants reflected on the details and risks of a clinical trial design (e.g., sham procedures) and described the different factors that relate to their decision to participate in a trial. Their main aspirations were to stop neurodevelopmental stagnation, to reduce seizures, and to reduce the impact on their families' wellbeing. To our knowledge, this is the first study within a patient-oriented research framework that specifically explored parents' needs and perceptions regarding clinical trials of a potential disease-modifying therapy for children with a severe, developmental disease, such as DS.

Dravet syndrome: Effects on informal caregivers' mental health and quality of life - A systematic review

BACKGROUND

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy, with predictable negative consequences for informal caregivers' mental health. This systematic review aimed to evaluate the representativeness of depression, anxiety, and burden in these caregivers and assess their quality of life.

METHODS

The PRISMA recommendations were followed, and a comprehensive search was conducted on PubMed/MEDLINE, WoS and Scopus databases, without date or language limits. Only observational quantitative studies on adult informal caregivers of patients with DS were considered.

RESULTS

Of 876 records found, 21 full-text articles were assessed and only 6 met the inclusion criteria. The latter have mostly a cross-sectional design and include samples composed by 19 to 742 caregivers, mainly mothers/females. Most of the study participants had a Bachelor's degree/higher educational level and were married. An important incidence of depression and anxiety on DS caregivers was reported, with significantly higher levels compared with population norms and with carers of other patients with epilepsy. Depression/anxiety were shown to be significantly associated with caregivers' fatigue and compromised sleep quality. Other important aspects of burden have been identified; however, comparisons between studies were not possible as different scales were used. Caregivers' health-related quality of life is also affected, with mothers reporting a worse perception on this domain.

CONCLUSIONS

Mental health and quality of life of DS caregivers are compromised, with mothers bearing an apparently greater burden. Studies using validated instruments for this population to assess the previously considered outcomes are needed, in order to inform the development of preventive strategies and problem-oriented interventions.

Improved everyday executive functioning following profound reduction in seizure frequency with fenfluramine: Analysis from a phase 3 long-term extension study in children/young adults with Dravet syndrome

OBJECTIVE

Individuals with Dravet syndrome (DS) experience frequent pharmacoresistant seizures beginning in infancy. Most exhibit poor neurodevelopmental outcomes including motor function difficulties, behavior problems, and cognitive impairment. Cognitive deficits in children with DS have been associated with seizure frequency and antiseizure medication (ASM) use. Recent research in children and young adults with DS has begun to examine the role of executive functions (EFs), as these include higher-order cognitive functions and may mediate the relationship between risk factors and cognitive impairment. Current conceptualizations, however, of EFs involve the broader self-regulation of cognitive, behavioral, and emotional domains. We explored relationships between reduction in convulsive seizure frequency and everyday EFs in a subset of children and young adults with DS treated with adjunctive fenfluramine for 1 year.

METHODS

This is a post-hoc analysis of data from children and young adults with Dravet syndrome aged 5-18 years who participated in a phase 3 randomized, placebo-controlled clinical trial (core study) followed by completion of at least 1 year of fenfluramine treatment in an open-label extension (OLE) study. Eligible children and young adults started the OLE study at 0.2 mg/kg/day fenfluramine and were titrated to optimal seizure control and tolerability (maximum daily dose: 26 mg/day). Parents/caregivers documented convulsive seizure frequency per 28 days (i.e., monthly convulsive seizure frequency [MCSF]) by electronic diary. A parent/caregiver for each child also completed the Behavior Rating Inventory of Executive Function (BRIEF®) parent form, a questionnaire capturing parents'/caregivers' perceptions of everyday EF that was included as a safety measure to assess treatment-related adverse effects on EF during the trial. Ratings on BRIEF® were mapped to the current edition, the BRIEF®2 parent form, and were used to calculate T-scores for the Behavior Regulation Index (BRI), Emotion Regulation Index (ERI), Cognitive Regulation Index (CRI), and Global Executive Composite (GEC). Change in BRIEF®2 T-scores from baseline in the core study to Year 1 of the OLE study was calculated. Spearman's rho correlation coefficients assessed associations between change in BRIEF®2 indexes/composite T-scores and percentage change in MCSF. Children and young adults were divided into 2 groups based on percentage of MCSF reduction achieved from pre-randomization baseline in the core study to Year 1 of the OLE study: <50% and ≥50% MCSF reduction. Changes in the distribution of BRIEF®2 indexes/composite T-scores were compared between MCSF reduction groups using Mann-Whitney U tests. The proportions of children and young adults in these groups who showed clinically meaningful improvement in everyday EF, defined as Reliable Change Index (RCI) values ≥95% certainty relative to a reference population of neurotypically developing healthy volunteers, were then assessed by cross-tabulations and Somers' D tests (p ≤ 0.05). When there was a significant meaningful improvement in an index score, post-hoc analyses using the same statistical methods were conducted to evaluate the individual BRIEF®2 scales composing that index. Supplemental analyses examined the proportions of patients in MCSF reduction groups <25% and ≥75% who achieved clinically meaningful improvement or worsening in everyday EF using RCI values ≥95% certainty and ≥80% certainty, respectively, relative to the reference population.

RESULTS

At the time of analysis, 58 children and young adults (mean age: 11 ± 4 years) had reached OLE Year 1 of fenfluramine treatment with a 75% median percentage reduction in seizure frequency from pre-randomization baseline. Overall, there was a significant correlation between change in MCSF and change in BRIEF®2 T-scores for ERI (p = 0.008), but not for BRI, CRI, or GEC (p > 0.05). At OLE Year 1, 78% (n = 45) of total children/young adults had ≥50% MCSF reduction (50% [n = 29] achieved ≥75% MCSF reduction) and 22% (n = 13) of total children/young adults had <50% MCSF reduction (12% [n = 7] showed <25% MCSF reduction). The ≥50% MCSF reduction group was significantly more likely to achieve clinically meaningful improvement (RCI ≥ 95% certainty) in ERI (p = 0.002) and in CRI (p = 0.001) than the <50% MCSF reduction group. There were no significant differences in the proportions of children and young adults in the 2 MCSF reduction groups showing clinically meaningful worsening (RCI ≥ 80% certainty) on the BRIEF®2 indexes/composite.

SIGNIFICANCE

In children and young adults with DS, the magnitude of reduction in MCSF after long-term treatment with adjunctive fenfluramine was associated with clinically meaningful levels of improvement in everyday EF. Seventy-eight percent (78%) of children and young adults treated with adjunctive fenfluramine for 1 year in the OLE study achieved ≥50% reduction in MCSF, for a magnitude of efficacy associated with a significantly greater likelihood of experiencing clinically meaningful improvement in emotion regulation and cognitive regulation.

Fenfluramine as antiseizure medication for epilepsy

Fenfluramine hydrochloride has classically been described as acting pharmacologically through a serotonergic mechanism. Therefore, it was initially used as an anorectic drug, given that impaired serotonin homeostasis may be associated with increased food intake. Although positive results were documented, cardiovascular concerns resulted in its temporary withdrawal. Nevertheless, a novel role in patients with epilepsy was later suggested by isolated clinical observations. The wide application of genetic testing allowed the classification (predominantly as Dravet syndrome) of patients in whom benefit was seen, while with the development of zebrafish models, its antiepileptic properties were confirmed at a molecular level. Data from randomized clinical trials have shown a beneficial effect of fenfluramine, as an adjunct therapy, on seizure control for children with Dravet syndrome, though there is still uncertainty about the impact on neurodevelopment in these patients. No signs of heart valve disease have been documented to date. Long-term and appropriately designed clinical studies will verify whether fenfluramine is a therapeutic agent of high importance, living up to the promise shown so far. What this paper adds Fenfluramine is a very promising repurposed therapy specifically for seizures in Dravet syndrome. The long-term effect of fenfluramine on neurodevelopmental prognosis requires further investigation.

Dravet Syndrome: Novel Approaches for the Most Common Genetic Epilepsy

Dravet syndrome (DS) is a severe developmental and epileptic encephalopathy that is mainly associated with variants in SCN1A. While drug-resistant epilepsy is the most notable feature of this syndrome, numerous symptoms are present that have significant impact on patients' quality of life. In spite of novel, third-generation anti-seizure treatment options becoming available over the last several years, seizure freedom is often not attained and non-seizure symptoms remain. Precision medicine now offers realistic hope for seizure freedom in DS patients, with several approaches demonstrating preclinical success. Therapeutic approaches such as antisense oligonucleotides (ASO) and adeno-associated virus (AAV)-delivered gene modulation have expanded the potential treatment options for DS, with some of these approaches now transitioning to clinical trials. Several of these treatments may risk the exacerbation of gain-of-function variants and may not be reversible, therefore emphasizing the need for functional testing of new pathogenic variants. The current absence of treatments that address the overall disease, in addition to seizures, exposes the urgent need for reliable, valid measures of the entire complement of symptoms as outcome measures to truly know the impact of treatments on DS. Additionally, with so many treatment options on the horizon, there will be a need to understand how to select appropriate patients for each treatment, whether treatments are complementary or adverse to each other, and long-term risks of the treatment. Nevertheless, precision therapeutics hold tremendous potential to provide long-lasting seizure freedom and even complete cures for this devastating disease.

Evaluation of the Aberrant Behavior Checklist for Developmental and Epileptic Encephalopathies

OBJECTIVES

To determine the suitability of the Aberrant Behavior Checklist (ABC)-a common measure used in clinical trials for treatment of challenging behaviors of autism-as an outcome measure for pharmacological and behavioral interventions for young people with Developmental and Epileptic Encephalopathies (DEEs).

METHODS

We assessed score profiles on the ABC in a sample of 122 young people with DEEs, including Dravet and Lennox-Gastaut syndromes, and KCNQ2- SCN2A-, and KCNB1-associated disorders. Then we examined its internal structure using item cluster analysis. We used both unrestricted item cluster analysis to determine the number of item clusters that maximize reliability and restricted analyses in which we pre-specified models with 5-, 6-, and 7-clusters, to examine consistency with previous factor analytic studies. We also conducted validity analysis on the various scoring methods with age, sex, and autism spectrum screening measure scores.

RESULTS

Unrestricted item cluster analysis suggested that three clusters maximized reliability of ABC scores. These broadly represented other-directed behaviors (i.e., "externalizing"), self-directed behaviors (i.e., "internalizing"), and inappropriate speech. Restricted models separated item clusters for stereotypy from other self-directed problem behaviors, and self-injurious behaviors from the other externalizing behaviors. Validity analysis also supported these structures. Overall, all scores were low, and less than 20% of DEE participants had symptoms severe enough to qualify for most randomized trials of behavioral therapies.

SIGNIFICANCE

These results are broadly consistent with the extant ABC scoring algorithms. They suggest a high internal consistency reliability, which may support the use of the ABC in future clinical trials in patients with DEEs who exhibit the behaviors assessed by the ABC. Alternatively, concerns about overall low scores raise cautions about using the ABC as a measure of behavior in unselected populations with DEE.

Neurocognitive Effects of Antiseizure Medications in Children and Adolescents with Epilepsy

Impairments in cognition are common in epilepsy and may be caused or exacerbated by antiseizure medications (ASMs). Positive effects on cognition may also be seen with some ASMs. Cognitive outcomes are of particular concern in children who may be at an increased risk of cognitive adverse effects of treatment. A comprehensive literature search was conducted in PubMed in order to evaluate the evidence for cognitive changes associated with treatment with ASMs in paediatric epilepsy patients. The ASMs considered were those in the current edition of the British National Formulary (BNF). For most ASMs, remarkably few studies providing robust data on cognitive effects in paediatric patients were identified. The available evidence suggests cognitive impairments may be associated with treatment with phenobarbital. Topiramate and phenytoin are also associated with negative effects on cognition, in particular word-finding difficulties and other language deficits with topiramate, but there are few data available specifically on children. Lamotrigine, levetiracetam and fenfluramine are associated with improvements in some cognitive domains, although it is unclear whether these effects are directly attributable to the medications or are a result of improvements in seizures. Neutral effects on cognition (no substantial evidence of worsening) were suggested for carbamazepine, everolimus, lacosamide, oxcarbazepine, perampanel and valproate. There is limited data for cannabidiol, clobazam, eslicarbazepine acetate, ethosuximide, rufinamide, vigabatrin and zonisamide, although the available evidence suggests these drugs are not associated with severe cognitive impairment. There was too little information to reach conclusions about the effects of brivaracetam, felbamate, gabapentin, pregabalin, retigabine, stiripentol or tiagabine.

Animal Models of Metabolic Epilepsy and Epilepsy Associated Metabolic Dysfunction: A Systematic Review

Epilepsy is a serious neurological disorder affecting around 70 million people globally and is characterized by spontaneous recurrent seizures. Recent evidence indicates that dysfunction in metabolic processes can lead to the alteration of neuronal and network excitability, thereby contributing to epileptogenesis. Developing a suitable animal model that can recapitulate all the clinical phenotypes of human metabolic epilepsy (ME) is crucial yet challenging. The specific environment of many symptoms as well as the primary state of the applicable neurobiology, genetics, and lack of valid biomarkers/diagnostic tests are the key factors that hinder the process of developing a suitable animal model. The present systematic review summarizes the current state of available animal models of metabolic dysfunction associated with epileptic disorders. A systematic search was performed by using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) model. A range of electronic databases, including google scholar, Springer, PubMed, ScienceDirect, and Scopus, were scanned between January 2000 and April 2020. Based on the selection criteria, 23 eligible articles were chosen and are discussed in the current review. Critical analysis of the selected literature delineated several available approaches that have been modeled into metabolic epilepsy and pointed out several drawbacks associated with the currently available models. The result describes available models of metabolic dysfunction associated with epileptic disorder, such as mitochondrial respiration deficits, Lafora disease (LD) model-altered glycogen metabolism, causing epilepsy, glucose transporter 1 (GLUT1) deficiency, adiponectin responsive seizures, phospholipid dysfunction, glutaric aciduria, mitochondrial disorders, pyruvate dehydrogenase (PDH) α-subunit gene (PDHA1), pyridoxine dependent epilepsy (PDE), BCL2-associated agonist of cell death (BAD), Kcna1 knock out (KO), and long noncoding RNAs (lncRNA) cancer susceptibility candidate 2 (lncRNA CASC2). Finally, the review highlights certain focus areas that may increase the possibilities of developing more suitable animal models and underscores the importance of the rationalization of animal models and evaluation methods for studying ME. The review also suggests the pressing need of developing precise robust animal models and evaluation methods for investigating ME.