Behavior problems and health-related quality of life in Dravet syndrome

Real-world experience of diagnosis, disability, and daily management in parents of children with different genetic developmental and epileptic encephalopathies: a qualitative study

PURPOSE

This study describes the experience of parents of children with developmental and epileptic encephalopathies (DEE) and how the disease impacts their daily lives.

MATERIALS AND METHODS

A descriptive qualitative study was conducted using purposeful sampling. Twenty-one parents of children with DEEs caused by SCN1A, KCNQ2, CDKL5, PCDH19, and GNAO1 variants were included. Data collection was based on in-depth interviews and researchers' field notes. An inductive thematic analysis was performed.

RESULTS

Five themes emerged: (a) the diagnostic process, which describes the path from the time parents recognize the first symptoms until diagnostic confirmation is obtained; (b) the relationship with health professionals during the search for a diagnosis, which describes how the entire process is conditioned by the relationships established; (c) the world of disability, revealing how the disease and disability impact the life of the parents; (d) living day to day, the parents continuously change their plans in anticipation of the onset of a seizure; (e) the disease progression, a cause of great concern in the parents.

CONCLUSIONS

Our results show the need to develop recovery programs that integrate health and social interventions to support parents of children with DEE in the process of diagnosis and disease management.

Neurodevelopmental defects in Dravet syndrome Scn1a+/- mice: Targeting GABA-switch rescues behavioral dysfunctions but not seizures and mortality

Dravet syndrome (DS) is a developmental and epileptic encephalopathy (DEE) caused by mutations of the SCN1A gene (NaV1.1 sodium channel) and characterized by seizures, motor disabilities and cognitive/behavioral deficits, including autistic traits. The relative role of seizures and neurodevelopmental defects in disease progression, as well as the role of the mutation in inducing early neurodevelopmental defects before symptoms' onset, are not clear yet. A delayed switch of GABAergic transmission from excitatory to inhibitory (GABA-switch) was reported in models of DS, but its effects on the phenotype have not been investigated. Using a multi-scale approach, here we show that targeting GABA-switch with the drugs KU55933 (KU) or bumetanide (which upregulate KCC2 or inhibits NKCC1 chloride transporters, respectively) rescues social interaction deficits and reduces hyperactivity observed in P21 Scn1a+/- DS mouse model. Bumetanide also improves spatial working memory defects. Importantly, neither KU nor bumetanide have effect on seizures or mortality rate. Also, we disclose early behavioral defects and delayed neurodevelopmental milestones well before seizure onset, at the beginning of NaV1.1 expression. We thus reveal that neurodevelopmental components in DS, in particular GABA switch, underlie some cognitive/behavioral defects, but not seizures. Our work provides further evidence that seizures and neuropsychiatric dysfunctions in DEEs can be uncoupled and can have differential pathological mechanisms. They could be treated separately with targeted pharmacological strategies.

Abnormal increased mTOR signaling regulates seizure threshold in Dravet syndrome

Excessive activation of mTOR has been observed in the brains of mouse models for Dravet syndrome. We aim to confirm whether that the overactivation of mTOR contributes to the neuropathological changes leading to epileptogenesis and neurobehavior deficits to support a novel pharmacological therapeutic approach for Dravet syndrome. The mTOR inhibitor everolimus, as a clinical antiseizure medication, was utilized to investigate whether mTOR is involved in hyperthermia-induced seizures, anxiety-like, and autism-like behaviors, as well as to explore potential pathogenic mechanisms in Scn1aE1099X/+ mice, a model of Dravet syndrome. First, we found that mTOR signaling was upregulated in hippocampus tissues and neural cultures derived from Scn1aE1099X/+ mice prior to seizure onset. Behaviorally, everolimus increased the seizure threshold and improved anxiety-like and autism-like behaviors in Scn1aE1099X/+ mice. Electrophysiologically, everolimus reduced the frequency of spontaneous excitatory postsynaptic currents in dentate granule neurons from Scn1aE1099X/+ mice. Biochemically, everolimus prevented hyperthermia-induced phosphorylation of hippocampal S6 ribosome in hippocampus, and it delayed hyperthermia-induced increase of cytosolic Ca2+ level in primary neuronal cultures derived from Scn1aE1099X/+ mice. Our results provide the evidence that overactivated mTOR as an important neuropathological change which regulates seizure threshold, impairments of neurobehavior, neuronal glutamatergic transmission and intracellular Ca2+ levels in Scn1aE1099X/+ mice. Inhibition of mTOR is a potential pharmacological therapeutic approach.

N-of-1 trials in epilepsy: A systematic review and lessons paving the way forward

OBJECTIVE

Defined as prospective single-patient crossover studies with repeated paired cycles of active and control intervention, N-of-1 trials have gained attention as an option to obtain high-quality evidence of efficacy, particularly for patients with rare epilepsies in whom conduction of well-powered randomized controlled trials can be challenging. The objective of this systematic review is to provide an appraisal of the literature on N-of-1 trials in individuals with epilepsy.

METHODS

We searched PubMed and Embase on January 12, 2024, for studies meeting the following criteria: prospectively planned, within-patient, multiple-crossover design in individuals with epilepsy and outcomes related to comorbidities. Information on design, outcome measurements, intervention, and analyses was retrieved. Risk of bias assessment was performed using the Risk of Bias in N-of-1 Trials (RoBiNT) scale. We highlighted methodological aspects of the N-of-1 trials identified and discuss future recommendations.

RESULTS

Five studies met our inclusion criteria. An additional multiple-crossover trial that evaluated treatment effects exclusively at group level was also included because of its relevance to N-of-1 study methodology. The studies enrolled individuals with focal seizures, absences or cognitive impairement and electrographic discharges. Treatments included established or investigational antiseizure medications, off-label medications, neurostimulation or lifestyle intervention. Three of the five N-of-1 trials reported on individual cases. The studies' strengths were the use of individualized treatment dosages and symptom-specific patient-reported outcomes. Limitations were related to minimal reporting of baseline characteristics and seizure burden.

SIGNIFICANCE

The trials identified by our search exemplify how the N-of-1 design can be applied to assess interventions in individuals with epilepsy-related disorders. Future N-of-1 trials of antiseizure interventions should take into account baseline seizure frequency, should apply statistical models suited to capture seizure frequency changes reliably and make predefined interim assessments. Non-seizure outcome measures evaluable over short periods should be considered. Tailored N-of-1 methodology could pave the way to evidence-based, treatment selection for patients with rare epilepsies.

Caregiver burden and therapeutic needs in Dravet syndrome - A national UK cross-sectional questionnaire study

BACKGROUND AND OBJECTIVES

Dravet Syndrome is a severe developmental and epileptic encephalopathy with significant care needs for affected individuals and families. Our objective was to characterise the caregiver burden and therapeutic needs of families caring for an individual with Dravet Syndrome from child to adulthood, to examine age related differences in co-morbidities, and identify current gaps in health and social care.

METHODS

Cross-sectional national survey conducted by the patient advocacy group Dravet Syndrome UK (DSUK) emailed to registered families caring for an individual with a confirmed diagnosis of Dravet syndrome. To characterise the sample, quantitative data on demographics, diagnostic journey, co-morbidities, therapies, healthcare utilisation, social care and funding, and impact on family life were collected. Qualitative data were analysed using grounded theory to develop a model of impact and service need.

RESULTS

165 out of 381 families (43 %) responded. 90 % of adult Dravet syndrome patients waited >12 months to receive a diagnosis, compared to 25 % families with a young child (p < 0.001). 96 % reported intellectual disability as co-morbidity, more frequently observed in older Dravet syndrome individuals (p < 0.001), alongside autism/autistic-like symptoms (χ2 = 15.3, df = 3 p = 0.001) and scoliosis (χ2 = 28.4, df = 3, p < 0.001). Sleep problems are associated with greater impact on caregiver's mental well-being (χ2 = 13.2, df = 2, p < 0.001). 77 % of families wished more discussions about sudden unexpected death in epilepsy (SUDEP) and 50 % rated the paediatric to adult transition experience as 'poor'. 90 % of caregivers were unable to continue working as normal with negative impact on their quality of life (p = 0.024) and mental well-being (p = 0.007).

DISCUSSION

Families are profoundly impacted by Dravet syndrome. Their experience changes over time as people with Dravet syndrome become older and present with increasing levels of health, cognitive and behavioural comorbidities. Families will benefit from improved communication with health care professionals, psychosocial interventions and better access to social care.

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.

Practical considerations for the use of fenfluramine to manage patients with Dravet syndrome or Lennox-Gastaut syndrome in clinical practice

Fenfluramine (FFA), an antiseizure medication (ASM) with serotonergic and sigma-1 receptor activity, is used to manage patients with developmental and epileptic encephalopathies (DEEs). It is approved in the US for treating seizures associated with Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) in patients ≥2 years old and as add-on therapy for seizures associated with DS and LGS in the EU, UK, and Japan in similarly aged patients. Consensus guidelines for treatment of DS have recommended FFA to be an early-line ASM, and it has also shown efficacy in managing seizures associated with LGS. DS and LGS are DEEs associated with a range of seizure types, developmental impairments, and multiple comorbidities. Here we provide case vignettes describing 4 patients (3 DS and 1 LGS) aged 4-29 years old in whom up to 14 ASMs had previously failed, to illustrate real-world practice issues encountered by neurologists. This review provides guidance on the use of FFA in the context of ASM polytherapy and drug-drug interactions (DDIs), behavioral issues, dose titration, and adverse events. Along with data from the clinical trial program, these case vignettes emphasize the low risk of DDIs, a generally well-tolerated safety profile, and other seizure and nonseizure benefits (eg, improved cognition and sleep) associated with the use of FFA in DS or LGS. PLAIN LANGUAGE SUMMARY: Fenfluramine is used to treat seizures in individuals with Dravet syndrome and Lennox-Gastaut syndrome, but there are a range of issues that clinicians may face when treating patients. This review highlights four patients from the authors' everyday clinical work and offers guidance and practical considerations by neurologists with expertise in managing these complex conditions related to drug interactions, dosing, and side effects associated with fenfluramine.

Quality of life in SCN1A-related seizure disorders across the lifespan

This cohort study aims to describe the evolution of disease features and health-related quality of life per life stage in Dravet syndrome and other SCN1A-related non-Dravet seizure disorders which will enable treating physicians to provide tailored care. Health-related quality of life and disease features were assessed cross-sectionally in participants with a SCN1A-related seizure disorder, categorized per age group for Dravet syndrome, and longitudinally over seven years follow-up (2015-2022). Data were collected from questionnaires, medical records, and semi-structured telephonic interviews. Health-related quality of life was measured with the Paediatric Quality of Life Inventory, proxy-reported for participants with Dravet syndrome and for participants with non-Dravet aged younger than 18 years old and self-reported for participants with non-Dravet over 18 years old. Associations between health-related quality of life and disease features were explored with multivariable regression analyses, cross-sectionally in a cohort of 115 patients with Dravet and 48 patients with generalized epilepsy with febrile seizures plus and febrile seizures (non-Dravet) and longitudinally in a cohort of 52 Dravet patients and 13 non-Dravet patients. In the cross-sectional assessment in 2022, health-related quality of life was significantly lower in Dravet syndrome, compared to non-Dravet and normative controls. Health-related quality of life in the School and Psychosocial domain was significantly higher in older Dravet age groups. A higher health-related quality of life was associated with fewer behavioural problems [β = -1.1; 95% confidence interval (CI), (-1.4 to -0.8)], independent walking (β = 8.5; 95%CI (4.2-12.8)), compared to the use of a wheelchair), and fewer symptoms of autonomic dysfunction (β = -2.1, 95%CI (-3.2 to -1.0)). Longitudinally, health-related quality of life was significantly higher seven years later in the course of disease in Dravet participants (Δ8.9 standard deviation (SD) 18.0, P < 0.05), mediated by a lower prevalence of behavioural problems (β = -1.2, 95%CI (-2.0 to -0.4)), lower seizure frequency (β = -0.1, 95%CI (-0.2 to -0.0)) and older age (β = 0.03, 95%CI (0.01-0.04)). In summary, health-related quality of life was significantly higher at older age in Dravet syndrome. This finding may reflect the benefits of an advanced care strategy in recent years and a ceiling of severity of disease symptoms, possibly resulting in an increased wellbeing of parents and patients. The strong association with behavioural problems reinforces the need to incorporate a multidisciplinary approach, tailored to the age-specific needs of this patient group, into standard care.

Comprehensive scoping review of fenfluramine's role in managing generalized tonic-clonic seizures in developmental and epileptic encephalopathies

Developmental and epileptic encephalopathies (DEEs) are characterized by pharmacoresistant seizures and developmental delay. Patients with DEEs experience multiple seizure types, including tonic-clonic seizures (TCS) that can be generalized tonic-clonic (GTCS) or focal evolving to bilateral tonic-clonic (FBTCS). Fenfluramine (FFA) has demonstrated efficacy in reduction of TCS in patients with Dravet syndrome (DS), Lennox-Gastaut syndrome (LGS), and other DEEs. Using the PRISMA-ScR (Preferred Reporting Items for Systematic Review and Meta-Analyses extension for Scoping Review) guidelines, we performed a scoping review to describe changes in TCS in patients treated with FFA. A comprehensive search of five literature databases was conducted up to February 14, 2023. Studies were included if they reported change in GTCS or TCS (but not FBTCS) after treatment with FFA in patients with DEEs. Duplicate patients and studies with unclear efficacy data were excluded. Fourteen of 422 studies met the eligibility criteria. Data extracted and evaluated by expert clinicians identified 421 unique patients with DS (in nine studies), CDKL5 deficiency disorder, SCN8A-related disorder, LGS, SCN1B-related disorder, and other DEEs. The median percent reduction in GTCS or TCS from baseline was available in 10 studies (n = 328) and ranged from 47.2% to 100%. Following FFA treatment, 10 studies (n = 144) reported ≥50% reduction in GTCS or TCS from baseline in 72% of patients; in nine of those (n = 112), 54% and 29% of patients achieved ≥75% and 100% reduction in GTCS or TCS from baseline, respectively. Overall, this analysis highlighted improvements in GTCS or TCS frequency when patients were treated with FFA regardless of the DEE evaluated. Future studies may confirm the impact of FFA on TCS reduction and on decreased premature mortality risk (including sudden unexpected death in epilepsy), improvement in comorbidities and everyday executive function, decreased health care costs, and improvement in quality of life.

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.

Attention-deficit/hyperactivity disorder in children with epilepsy: A systematic review and meta-analysis of prevalence and risk factors

OBJECTIVE

To evaluate the prevalence of and risk factors for attention-deficit/hyperactivity disorder (ADHD) in children with epilepsy (CWE).

METHODS

We conducted a systematic search in PubMed and Embase for the meta-analysis. The pooled prevalence of ADHD was calculated using a random-effects model; subgroup analyses were performed to explore heterogeneity. We collected raw data from articles reporting potential risk factors, which were included in the subsequent risk factor analysis.

RESULTS

Forty-six articles met the inclusion criteria for the meta-analysis, which showed a pooled ADHD prevalence of 30.7% in CWE, with a predominance of the inattentive subtype of ADHD; the heterogeneity of prevalence was related to population source/study setting (clinic based, community based, or database based) and method of ADHD diagnosis (with or without clinical review). Risk factors for ADHD in epilepsy included younger age, intellectual/developmental disabilities, a family history of epilepsy, earlier epilepsy onset, absence epilepsy, more frequent seizures, and polytherapy; In contrast, risk factors such as sex, generalized epilepsy or seizures, epilepsy etiology, and electroencephalogram abnormalities were not significantly associated with the occurrence of ADHD.

SIGNIFICANCE

The prevalence of ADHD in CWE is high and several potential risk factors are associated with it. This study contributes to a better understanding of ADHD in epilepsy for screening and treatment.

PLAIN LANGUAGE SUMMARY

This systematic review summarizes the prevalence of attention-deficit/hyperactivity disorder (ADHD) occurring in children with epilepsy and analyses the risk factors for comorbid ADHD in epilepsy. By reviewing 46 articles, we concluded that the overall prevalence of ADHD in children with epilepsy was 30.7% and that intellectual/developmental disabilities were the most significant risk factor for combined ADHD in children with epilepsy. This study provides a wealth of information on comorbid ADHD in epilepsy, which will help clinicians identify and treat potential ADHD in children with epilepsy in a timely manner.

The impact of developmental and epileptic encephalopathies on families: a qualitative study

Developmental and epileptic encephalopathies (DEEs) cause disability and dependence affecting both children and the family. The aim of the study was to describe the perspective of parents of children with DEEs regarding the impact of the disease on the family. We carried out a qualitative study based on the interpretivist paradigm. Twenty-one participants were selected using purposive sampling. Parents of children with DEEs of SCN1A, KCNQ2, CDKL5, PCDH19, and GNAO1 variants were included. In-depth interviews and researcher notes were used for data collection. A thematic analysis was performed on the data. Three themes were identified in the results: (a) Assuming conflicts and changes within the couple, causing them to distance themselves, reducing their time and intimacy and leading them to reconsider having more children; (b) impact of the disorder on siblings and grandparents, where siblings perceived DEE as a burden in their lives, felt neglected, and needed to grow and mature alone; conversely, the grandparents suffered for their grandchildren and the parents, in addition to perceiving that their health worsened, and (c) reconciling the care of the child with family life and work; this led the parents to share tasks, abandon or reduce working hours and ask for help.Conclusions: Caring for a child with DEE can result in neglect of social, psychological, emotional, recreational, educational, or occupational needs and obligations that ultimately impact all family members. What is Known: • Children with DEE may develop seizures and experience developmental and cognitive problems. • Caring for a child with DEE has a social and psychological impact on the entire family.

Caring for a child with DEE has a social and psychological impact on the entire family.

What is New: • Within the couple, there are tensions due to a lack of time, which could be alleviated by alternating childcare duties. • It is necessary to implement programs that address the physical and mental needs of the couple, as well as cater to the needs of siblings and alleviate the suffering of grandparents.

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.

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.

The burden of epilepsy on long-term outcome of genetic developmental and epileptic encephalopathies: A single tertiary center longitudinal retrospective cohort study

BACKGROUND

This retrospective cohort analysis highlighted neurodevelopmental outcome predictors of genetic developmental and epileptic encephalopathies (DEE).

PATIENTS AND METHODS

Patients' demographic, clinical and molecular genetics data were collected. All patients underwent clinical, developmental, and neuropsychological assessments.

RESULTS

We recruited 100 participants (53 males, 47 females) with a mean follow-up lasting 10.46 ± 8.37 years. Age at epilepsy-onset was predictive of poor adaptive and cognitive functions (VABS-II score, r = 0.350, p = 0.001; BRIEF control subscale, r = -0.253; p = 0.031). Duration of epilepsy correlated negatively with IQ (r = -0.234, p = 0.019) and VABS-II score (r = -0.367, p = 0.001). Correlations were found between delayed/lacking EEG maturation/organization and IQ (r = 0.587, p = 0.001), VABS-II score (r = 0.658, p = 0.001), BRIEF-MI and BRIEF-GEC scores (r = -0.375, p = 0.001; r = -0.236, p = 0.033), ASEBA anxiety (r = -0.220, p = 0.047) and ADHD (r = -0.233, p = 0.035) scores. The number of antiseizure medications (ASMs) correlated with IQ (r = -0.414, p = 0.001), VABS-II (r = -0.496, p = 0.001), and BRIEF-MI (r = 0.294, p = 0.012) scores; while age at the beginning of therapy with ASEBA anxiety score (r = 0.272, p = 0.013). The occurrence of status epilepticus was associated with worse adaptive performances. The linear regression analysis model showed that delayed/lacking EEG maturation/organization had a significant influence on the IQ (R2 = 0.252, p < 0.001) and the BRIEF-GEC variability (R2 = 0.042, p = 0.036). The delayed/lacking EEG maturation/organization and the duration of epilepsy also had a significant influence on the VABS-II score (R2 = 0.455, p = 0.005).

CONCLUSIONS

Age at seizure-onset, EEG maturation/organization, duration of epilepsy, occurrence of status epilepticus, age at the introduction and number of ASMs used are reliable predictors of long-term outcomes in patients with genetic DEE.

Health care concerns in parents of children with different genetic developmental and epileptic encephalopathies: A qualitative study

AIM

To describe the experiences and unmet medical care needs of a group of parents of children with developmental and epileptic encephalopathies (DEEs) caused by the SCN1A, KCNQ2, CDKL5, PCDH19, and GNAO1 variants.

METHOD

A qualitative descriptive study was conducted. Participants were recruited using purposeful sampling. The inclusion criteria consisted of parents of children with DEEs caused by the SCN1A, KCNQ2, CDKL5, PCDH19, or GNAO1 variants, aged between 4 and 10 years old. In total, 21 parents were included. Data were acquired via researcher field notes and in-depth interviews. A thematic analysis was performed.

RESULTS

Three main themes were identified: (1) managing symptoms: epileptic seizures are experienced with great uncertainty and are accompanied by cognitive, behavioural, and motor symptoms; (2) accepting treatment: the ideal medication regimen is a challenge and the decision to withdraw or start a new therapy falls on the parents; and (3) therapeutic relationship and medical care: behaviours related to the health professional can hinder the therapeutic relationship with the parents. Parents are apprehensive about going to the emergency department.

INTERPRETATION

Professionals in emergency departments should acquire better knowledge of DEEs, welcome parents, and improve treatment for the children. The results of this study can serve as a starting point for a roadmap of relevant caregiver-reported outcomes in DEEs, to be implemented with new clinical trials and aetiology-targeted therapies.

WHAT THIS PAPER ADDS

Epileptic seizures are the symptom that is most experienced and feared by parents. The medication regime has no defined protocol and the decision to withdraw a medication is frequently left to parents.

Preocupaciones sobre la atención sanitaria en progenitores de niños con diferentes encefalopatías epilépticas genéticas del desarrollo: Un estudio cualitativo

Objetivo

Describir las experiencias y las necesidades de atención médica de un grupo de progenitores de niños con encefalopatías epilépticas y del desarrollo (EED) causadas por las variantes SCN1A, KCNQ2, CDKL5, PCDH19 y GNAO1.

Método

Se realizó un estudio cualitativo descriptivo. Los participantes fueron reclutados mediante un muestreo intencional. Los criterios de inclusión consistieron en progenitores de niños con EED causadas por las variantes SCN1A, KCNQ2, CDKL5, PCDH19 o GNAO1, con edades comprendidas entre los 4 y los 10 años. En total, se incluyeron 21 progenitores. Los datos se obtuvieron mediante entrevistas en profundidad y notas de campo del investigador. Se realizó un análisis temático.

Resultados

Se identificaron tres temas principales: (1) Manejando los síntomas, las crisis epilépticas se viven con gran incertidumbre, y se acompañan de síntomas cognitivos, conductuales y motores que limitan la vida del niño; b) Aceptando el tratamiento, la pauta de la medicación idónea es un reto, la decisión de retirar o comenzar una nueva terapia recae en los progenitores; y c) Relación terapéutica y atención médica, existen comportamientos y acciones del profesional que facilitan o dificultan la relación terapéutica con los progenitores. Acudir al servicio de urgencias es vivido con recelo por los progenitores.

Interpretación

Los profesionales de los servicios de urgencias deben conocer mejor las EED, acoger a los progenitores y mejorar el tratamiento de los niños. Los resultados de este estudio pueden servir como punto de partida para una hoja de ruta de los resultados relevantes reportados por los cuidadores de las EED, a implementar nuevos ensayos clínicos y terapias dirigidas a la etiología.

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Self- and Caregiver-Reported Participation, Quality of Life, and Related Mood and Behavior Challenges in People Living With Dystrophinopathies

BACKGROUND

Previous studies of quality of life (QOL), mood, and behavior in muscular dystrophy focus on caregiver perceptions. This cross-sectional study aims to determine the prevalence of clinically significant mood and behavior problems by both patient and caregiver report and assess relationship between mood/behavior and QOL.

METHODS

Forty-one patients with dystrophinopathies (Duchenne muscular dystrophy [DMD] and Becker muscular dystrophy [BMD]) were recruited through the University of Virginia Neuromuscular Clinic. Each patient and caregiver dyad completed questionnaires, including the Behavior Assessment System for Children, 2nd Edition (BASC-2); the Pediatric Quality of Life Inventory for DMD (PedsQL-DMD); Children's Depression Inventory, 2nd Edition; and Screen for Child Anxiety Related Disorders.

RESULTS

Persons with dystrophinopathies rated most of their behavior and adaptive skills similarly to the general population. Sixty-four percent of parent assessments rated clinically significant problems on the BASC-2. Worse BASC-2 scores for self- and parent assessments correlated with lower (worse) scores in the Worry and Communication PedsQL domains. Patient-reported QOL scores were higher than parent-reported scores in each domain except Worry.

CONCLUSIONS

Individuals with DMD/BMD rate their adaptive skills, behavioral symptoms, externalizing and internalizing problems, and school problems more positively than parents/caregivers. Obtaining self-report data is a worthwhile endeavor that can add value to intervention planning, with the ultimate goal of optimizing QOL.

A European pilot study in Dravet Syndrome to delineate what really matters for the patients and families

We aimed to identify caregivers' opinions on the outcome measures that matter in clinical trials in individuals with Dravet syndrome (DS). We conducted a prospective European multicenter study based on an 11 closed questions survey developed by the French reference center for rare epilepsies and DS patients' advocacy groups. Items included questions on seizures and daily life outcomes that a clinical trial on a therapy for individuals with DS should target. Statistical analyses were performed to evaluate the impact of the country of residence and of the patients' age. The survey was answered by 153 caregivers (68%: France, 28%: Germany, and 24%: Italy) off individuals with DS. Individuals with DS included 86 males (mean age of 11.4 [interquartile: 7-20.4] years). Families ranked as important almost all the items proposed. However, items related to daily life had the highest rank in all three countries compared to items about seizures (P = 0.02). Increase in individuals' age was associated with a higher age at diagnosis (ρ = 0.26, P = 0.02), and a lower impact of seizure duration (ρ = -0.25, P = 0.005) and on the need of hospital referral (ρ = -0.26, P = 0.005). These data can help tailor patient-centered outcome measures in future clinical and real-life trials for DS.

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.

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.

Therapeutic effects of KRM-II-81, positive allosteric modulator for α2/3 subunit containing GABAA receptors, in a mouse model of Dravet syndrome

Introduction: Dravet syndrome (DS) is an intractable epilepsy syndrome concomitant with neurodevelopmental disorder that begins in infancy. DS is dominantly caused by mutations in the SCN1A gene, which encodes the α subunit of a voltage-gated Na channel. Pre-synaptic inhibitory dysfunction is regarded as the pathophysiological mechanism, but an effective strategy for ameliorating seizures and behavioral problems is still under development. Here, we evaluated the effects of KRM-II-81, a newly developed positive allosteric modulator for α 2/3 subunit containing GABAA receptors (α2/3-GABAAR) in a mice model of DS both in vivo and at the neuronal level. Methods: We used knock-in mice carrying a heterozygous, clinically relevant SCN1A mutation (background strain: C57BL/6 J) as a model of the DS (Scn1a WT/A1783V mice), knock-in mouse strain carrying a heterozygous, clinically relevant SCN1A mutation (A1783V). Seizure threshold and locomotor activity was evaluated by using the hyperthermia-induced seizure paradigm and open filed test, respectively. Anxiety-like behavior was assessed by avoidance of the center region in locomotor activity. We estimated a sedative effect by the total distance traveled in locomotor activity and grip strength. Inhibitory post synaptic currents (IPSCs) were recorded from a hippocampal CA1 pyramidal neuron in an acutely prepared brain slice. Results: KRM-II-81 significantly increased the seizure threshold of Scn1a WT/A1783V mice in a dose-dependent manner. A low dose of KRM-II-81 specifically improved anxiety-like behavior of Scn1a WT/A1783V mice. A sedative effect was induced by relatively high dose of KRM-II-81 in Scn1a WT/A1783V mice, the dose of which was not sedative for WT mice. KRM-II-81 potentiated IPSCs by increasing its decay time kinetics. This effect was more prominent in Scn1a WT/A1783V mice. Discussion: Higher activation of α2/3-GABAAR by KRM-II-81 suggests a compensatory modification of post synaptic inhibitory function against presynaptic inhibitory dysfunction in Scn1a WT/A1783V. The increased sensitivity for KRM-II-81 may be relevant to the distinct dose-dependent effect in each paradigm of Scn1a WT/A1783V mice. Conclusion: Selective activation for α2/3-GABAAR by KRM-II-81 could be potential therapeutic strategy for treating seizures and behavioral problems in DS.

Determining the Relationship Between Seizure-Free Days and Other Predictors of Quality of Life in Patients with Dravet Syndrome and Their Carers from FFA Registration Studies

INTRODUCTION

Dravet syndrome (DS) is a rare, lifelong epileptic encephalopathy characterised by frequent and severe seizures associated with premature mortality. Typically diagnosed in infancy, patients also experience progressive behavioural, motor-function and cognitive decline. Twenty percent of patients do not reach adulthood. Quality of life (QoL) is impaired for both patients and their carers. Reducing convulsive seizure frequency, increasing convulsive seizure-free days (SFDs) and improving patient/carer QoL are primary treatment goals in DS. This study explored the relationship between SFDs and patients' and carers' QoL to inform a cost-utility analysis of fenfluramine (FFA).

METHODS

In FFA registration studies, patients (or their carer proxies) completed the Paediatric QoL inventory (PedsQL). These data were mapped to EuroQol-5 Dimensions Youth version (EQ-5D-Y) to provide patient utilities. Carer utilities were collected using EQ-5D-5L and mapped to EQ-5D-3L to align patient and carer QoL on the same scale. Linear mixed-effects and panel regression models were tested and Hausman tests identified the most appropriate approach for each group. On this basis, a linear mixed-effects regression model was used to examine the relationships between patient EQ-5D-Y and clinically relevant variables (age, frequency of SFDs per 28 days, motor impairments and treatment dose). A linear panel regression model examined the relationship between SFDs and carer QoL.

RESULTS

After adjustment for age and underlying comorbidities, the patient regression model showed that SFDs per 28 days was a significant predictor of QoL. Each additional patient-SFD increased utility by 0.005 (p < 0.001). The carer linear panel model also showed that increasing SFDs per 28 days was a significant predictor of improved QoL. Each additional SFD increased carer utility by 0.014 (p < 0.001).

CONCLUSION

This regression framework highlights that SFDs are significantly correlated with both patients' and carers' QoL. Treatment with effective antiseizure medications that increase SFDs directly improves QoL for patients and their carers.

Gastrointestinal and eating problems in SCN1A-related seizure disorders

OBJECTIVE

Our study aimed to describe the prevalence and characteristics of gastrointestinal and eating problems in Dravet syndrome (DS) and other SCN1A-related seizure disorders and to determine the association between the occurrence of gastrointestinal and eating problems and core features of DS.

METHODS

Gastrointestinal and eating problems were assessed with a questionnaire in a Dutch cohort of participants with an SCN1A-related seizure disorder. Associations between the number of gastrointestinal and eating problems and core features of DS, seizure severity, level of intellectual disability, impaired mobility, behavioral problems, and use of anti-seizure medication, were explored by multivariate ordinal regression analyses. Symptoms were divided into the categories dysphagia-related, behavioral, and gastrointestinal, and were assessed separately.

RESULTS

One hundred sixty-nine participants with an SCN1A-related seizure disorder, of whom 118 (69.8%) with DS and 51 (30.2%) with Generalized Epilepsy with Febrile Seizures Plus / Febrile Seizures (GEFS+/FS), the non-DS phenotype, were evaluated. Gastrointestinal and eating problems were highly prevalent in DS participants, 50.8% had more than three symptoms compared to 3.9% of non-DS participants. Of participants with DS, 17.8% were fully or partly fed by a gastric tube. Within the three different symptom categories, the most prevalent dysphagia-related symptom was drooling (60.7%), distraction during mealtimes (61.4%) the most prevalent behavioral symptom, and constipation and loss of appetite (both 50.4%) the most prevalent gastrointestinal symptoms. DS participants who use a wheelchair (odds ratio (OR) 4.9 95%CI (1.9-12.8) compared to walking without aid), who use ≥3 anti-seizure medications (ASM) (OR 5.9 95%CI (1.9-18.2) compared to <3 ASM) and who have behavioral problems (OR 3.0 95%CI (1.1-8.1) compared to no behavioral problems) had more gastrointestinal and eating problems.

CONCLUSION

Gastrointestinal and eating problems are frequently reported symptoms in DS. Distinguishing between symptom categories will lead to tailored management of patients at risk, will improve early detection, and enable a timely referral to a dietitian, behavioral expert, and/or speech therapist, ultimately aiming to improve the quality of life of both patients and caregivers.

Red blood cells as glucose carriers to the human brain: Modulation of cerebral activity by erythrocyte exchange transfusion in Glut1 deficiency (G1D)

Red blood cells circulating through the brain are briefly but closely apposed to the capillary endothelium. We hypothesized that this contact provides a nearly direct pathway for metabolic substrate transfer to neural cells that complements the better characterized plasma to endothelium transfer. While brain function is considered independent of normal fluctuations in blood glucose concentration, this is not borne out by persons with glucose transporter I (GLUT1) deficiency (G1D). In them, encephalopathy is often ameliorated by meal or carbohydrate administration, and this enabled us to test our hypothesis: Since red blood cells contain glucose, and since the red cells of G1D individuals are also deficient in GLUT1, replacing them with normal donor cells via exchange transfusion could augment erythrocyte to neural cell glucose transport via mass action in the setting of unaltered erythrocyte count or plasma glucose abundance. This motivated us to perform red blood cell exchange in 3 G1D persons. There were rapid, favorable and unprecedented changes in cognitive, electroencephalographic and quality-of-life measures. The hypothesized transfer mechanism was further substantiated by in vitro measurement of direct erythrocyte to endothelial cell glucose flux. The results also indicate that the adult intellect is capable of significant enhancement without deliberate practice.      ClinicalTrials.gov registration: NCT04137692 https://clinicaltrials.gov/ct2/show/NCT04137692.

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.

Psychobehavioural and Cognitive Adverse Events of Anti-Seizure Medications for the Treatment of Developmental and Epileptic Encephalopathies

The developmental and epileptic encephalopathies encompass a group of rare syndromes characterised by severe drug-resistant epilepsy with onset in childhood and significant neurodevelopmental comorbidities. The latter include intellectual disability, developmental delay, behavioural problems including attention-deficit hyperactivity disorder and autism spectrum disorder, psychiatric problems including anxiety and depression, speech impairment and sleep problems. Classical examples of developmental and epileptic encephalopathies include Dravet syndrome, Lennox-Gastaut syndrome and tuberous sclerosis complex. The mainstay of treatment is with multiple anti-seizure medications (ASMs); however, the ASMs themselves can be associated with psychobehavioural adverse events, and effects (negative or positive) on cognition and sleep. We have performed a targeted literature review of ASMs commonly used in the treatment of developmental and epileptic encephalopathies to discuss the latest evidence on their effects on behaviour, mood, cognition, sedation and sleep. The ASMs include valproate (VPA), clobazam, topiramate (TPM), cannabidiol (CBD), fenfluramine (FFA), levetiracetam (LEV), brivaracetam (BRV), zonisamide (ZNS), perampanel (PER), ethosuximide, stiripentol, lamotrigine (LTG), rufinamide, vigabatrin, lacosamide (LCM) and everolimus. Bromide, felbamate and other sodium channel ASMs are discussed briefly. Overall, the current evidence suggest that LEV, PER and to a lesser extent BRV are associated with psychobehavioural adverse events including aggressiveness and irritability; TPM and to a lesser extent ZNS are associated with language impairment and cognitive dulling/memory problems. Patients with a history of behavioural and psychiatric comorbidities may be more at risk of developing psychobehavioural adverse events. Topiramate and ZNS may be associated with negative effects in some aspects of cognition; CBD, FFA, LEV, BRV and LTG may have some positive effects, while the remaining ASMs do not appear to have a detrimental effect. All the ASMs are associated with sedation to a certain extent, which is pronounced during uptitration. Cannabidiol, PER and pregabalin may be associated with improvements in sleep, LTG is associated with insomnia, while VPA, TPM, LEV, ZNS and LCM do not appear to have detrimental effects. There was variability in the extent of evidence for each ASM: for many first-generation and some second-generation ASMs, there is scant documented evidence; however, their extensive use suggests favourable tolerability and safety (e.g. VPA); second-generation and some third-generation ASMs tend to have the most robust evidence documented over several years of use (TPM, LEV, PER, ZNS, BRV), while evidence is still being generated for newer ASMs such as CBD and FFA. Finally, we discuss how a variety of factors can affect mood, behaviour and cognition, and untangling the associations between the effects of the underlying syndrome and those of the ASMs can be challenging. In particular, there is enormous heterogeneity in cognitive, behavioural and developmental impairments that is complex and can change naturally over time; there is a lack of standardised instruments for evaluating these outcomes in developmental and epileptic encephalopathies, with a reliance on subjective evaluations by proxy (caregivers); and treatment regimes are complex involving multiple ASMs as well as other drugs.

The Charlotte Project: Recommendations for patient-reported outcomes and clinical parameters in Dravet syndrome through a qualitative and Delphi consensus study

Objective

The appropriate management of patients with Dravet Syndrome (DS) is challenging, given the severity of symptoms and the burden of the disease for patients and caregivers. This study aimed to identify, through a qualitative methodology and a Delphi consensus-driven process, a set of recommendations for the management of DS to guide clinicians in the assessment of the clinical condition and quality of life (QoL) of DS patients, with a special focus on patient- and caregiver-reported outcomes (PROs).

Methods

This study was conducted in five phases, led by a multidisciplinary scientific committee (SC) including pediatric neurologists, epileptologists, a neuropsychologist, an epilepsy nurse, and members of DS patient advocates. In phases 1 and 2, a questionnaire related to patients' QoL was prepared and answered by caregivers and the SC. In phase 3, the SC generated, based on these answers and on a focus group discussion, a 70-item Delphi questionnaire, covering six topic categories on a nine-point Likert scale. In phase 4, 32 panelists, from different Spanish institutions and with a multidisciplinary background, answered the questionnaire. Consensus was obtained and defined as strong or moderate if ≥80% and 67–79% of panelists, respectively, rated the statement with ≥7. Phase 5 consisted of the preparation of the manuscript.

Results

The panelists agreed on a total of 69 items (98.6%), 54 (77.14%), and 15 (21.43%) with strong and moderate consensus, respectively. The experts' recommendations included the need for frequent assessment of patient and caregivers QoL parameters. The experts agreed that QoL should be assessed through specific questionnaires covering different domains. Likewise, the results showed consensus regarding the regular evaluation of several clinical parameters related to neurodevelopment, attention, behavior, other comorbidities, and sudden unexpected death in epilepsy (SUDEP). A consensus was also reached on the instruments, specific parameters, and caregivers' education in the routine clinical management of patients with DS.

Conclusions

This consensus resulted in a set of recommendations for the assessment of clinical and QoL parameters, including PROs, related to the general evaluation of QoL, neurodevelopment, attention, behavior, other comorbidities affecting QoL, SUDEP, and QoL of caregivers/relatives and patients with DS.

Exploring the relationships between composite scores of disease severity, seizure-freedom and quality of life in Dravet syndrome

BACKGROUND

In Dravet syndrome (DS), a rare epileptic and developmental encephalopathy, the effectiveness of a new treatment is predominantly measured in terms of seizure frequency. However, this may not fully capture the impact of a treatment on the broader aspects of the syndrome and patients' health-related quality of life (HRQoL). Using a previously published survey which collected data from DS patients and their carers on the broader manifestations of their syndrome, their HRQoL, and their experience of seizures, this study created composite measures of symptom severity to offer new perspectives on the multifaceted aspects of this rare condition.

METHODS

Survey responses on the severity of physical and psychosocial symptoms were combined with independent assessments of disability and care need, to generate three composite symptom scores assessing the manifestations of DS (physical, psychosocial and care requirements). Variation in HRQoL was investigated in multiple regression analyses to assess the strength of association between each of these composite measures and three forms of seizure measures (seizure frequency, days with no seizures and longest interval without seizures), as experienced over a 4- and 12-week period.

RESULTS

Composite scores were calculated for a cohort of 75 primarily paediatric patients who were enrolled in the study. Strong associations were found between each of the three composite symptom scores and each of the three seizure measures, with the regression coefficient on symptom score highly significant (p ≤ 0.001) in all nine comparisons. Separate regressions using predictors of HRQoL (Kiddy KINDL and Kid KINDL) as the dependent variable were inconclusive, identifying only behavioural/attention problems and status epilepticus as significant predictors of HRQoL.

CONCLUSIONS

These results allow the development of a composite score that may be useful in developing a clinical understanding of the severity of DS for an individual patient and establishing their treatment goals. Where measurement of long-term sequalae of disease is not feasible, such as clinical trials, correlation of the composite score with experience of seizures and seizure-free periods may allow a better contextualisation of the results of short-term assessments.

TRIAL REGISTRATION

German Clinical Trials Register (DRKS), DRKS00011894. Registered 16 March 2017, http://www.drks.de/ DRKS00011894.

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.

Life-span characterization of epilepsy and comorbidities in Dravet syndrome mice carrying a targeted deletion of exon 1 of the Scn1a gene

OBJECTIVE

Dravet Syndrome (DS) is a catastrophic form of paediatric epilepsy associated with multiple comorbidities mainly caused by mutations in the SCN1A gene. DS progresses in three different phases termed febrile, worsening and stabilization stage. Mice that are haploinsufficient for Scn1a faithfully model each stage of DS, although various aspects have not been fully described, including the temporal appearance and sex differences of the epilepsy and comorbidities. The aim of the present study was to investigate the epilepsy landscape according to the progression of DS and the long-term co-morbidities in the Scn1a(+/-)^tm1Kea DS mouse line that are not fully understood yet.

METHODS

Male and female F1.Scn1a(+/+) and F1.Scn1a(+/-)^tm1Kea mice were assessed in the hyperthermia model or monitored by video electroencephalogram (vEEG) and wireless video-EEG according to the respective stage of DS. Long-term comorbidities were investigated through a battery of behaviour assessments in ~6 month-old mice.

RESULTS

At P18, F1.Scn1a(+/-)^tm1Kea mice showed the expected sensitivity to hyperthermia-induced seizures. Between P21 and P28, EEG recordings in F1.Scn1a(+/-)^tm1Kea mice combined with video monitoring revealed a high frequency of SRS and SUDEP. Power spectral analyses of background EEG activity also revealed that low EEG power in multiple frequency bands was associated with SUDEP risk in F1.Scn1a(+/-)^tm1Kea mice during the worsening stage of DS. Later, SRS and SUDEP rates stabilized and then declined in F1.Scn1a(+/-)^tm1kea mice. Incidence of SRS ending with death in F1.Scn1a(+/-)^tm1kea mice displayed variations with the time of day and sex, with female mice displaying higher numbers of severe seizures resulting in greater SUDEP risk. F1.Scn1a(+/-)^tm1kea mice ~6 month-old displayed fewer behavioural impairments than expected including hyperactivity, impaired exploratory behaviour and poor nest building performance.

SIGNIFICANCE

These results reveal new features of this model that will optimize use and selection of phenotype assays for future studies on the mechanisms, diagnosis, and treatment of DS.

Generation and Characterization of the Drosophila melanogaster paralytic Gene Knock-Out as a Model for Dravet Syndrome

Dravet syndrome is a severe rare epileptic disease caused by mutations in the SCN1A gene coding for the Nav1.1 protein, a voltage-gated sodium channel alpha subunit. We have made a knock-out of the paralytic gene, the single Drosophila melanogaster gene encoding this type of protein, by homologous recombination. These flies showed a heat-induced seizing phenotype, and sudden death in long term seizures. In addition to seizures, neuromuscular alterations were observed in climbing, flight, and walking tests. Moreover, they also manifested some cognitive alterations, such as anxiety and problems in learning. Electrophysiological analyses from larval motor neurons showed a decrease in cell capacitance and membrane excitability, while persistent sodium current increased. To detect alterations in metabolism, we performed an NMR metabolomic profiling of heads, which revealed higher levels in some amino acids, succinate, and lactate; and also an increase in the abundance of GABA, which is the main neurotransmitter implicated in Dravet syndrome. All these changes in the paralytic knock-out flies indicate that this is a good model for epilepsy and specifically for Dravet syndrome. This model could be a new tool to understand the pathophysiology of the disease and to find biomarkers, genetic modifiers and new treatments.

Patient and Caregiver Health State Utilities in Lennox-Gastaut Syndrome and Dravet Syndrome

PURPOSE

Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare, treatment-resistant forms of epilepsy characterized by childhood onset of seizures. Cost-effectiveness analysis for new antiseizure medications typically requires health state utilities (HSUs) that reflect the patient and caregiver burden of the relevant conditions. This study aimed to estimate HSUs for LGS and DS. Focus was placed on valuing the impact of seizure frequency and seizure-free days on health-related quality of life (HRQL) for patients and caregivers.

METHODS

Health state vignettes that described the experience of living with and caring for a child with LGS or DS were developed based on a targeted literature review and feedback from interviews with LGS and DS clinical experts and DS caregivers. Vignettes varied by the number of seizures and seizure-free days per month. Twenty-four vignettes were developed that described patient HRQL (6 per condition) and caregiver HRQL (6 per condition) for LGS or DS. Vignettes were evaluated via interviews from the general population in the United Kingdom and Sweden using a visual analog scale and time trade-off (TTO) method. Participants were recruited by interviewers based in different regions of the United Kingdom and Sweden using convenience sampling.

FINDINGS

Two hundred interviews were conducted by video call from March to April 2020. One hundred participants evaluated each of the 6 patient and 6 caregiver vignettes for LGS; a different 100 participants evaluated each of the DS vignettes. The estimated utility values vary consistently according to seizure frequency and number of seizure-free days. Patient TTO utility values range from -0.186 (highest seizure frequency and fewest seizure-free days) to 0.754 (seizure-free state) for LGS and from 0.171 to 0.778 for DS. The caregiver TTO utility values range from 0.032 to 0.810 and 0.510 to 0.881 for LGS and DS, respectively. Fewer seizures and additional seizure-free days are associated with better patient and caregiver HRQL.

IMPLICATIONS

This study estimated utility values for patients with LGS or DS and their caregivers using visual analog scale and TTO valuation among a general public sample. These utility values can be used in cost-effectiveness assessments of new antiseizure medications. The findings indicate the importance of seizure-free days as well as seizure frequency in patient and caregiver HRQL, which may inform the design of future clinical trials.

Dravet syndrome: A quick transition guide for the adult neurologist

INTRODUCTION

Dravet syndrome (DS) is still seen as a "pediatric disease", where patients receive excellent care in pediatric centers, but care is less than optimal in adult health care systems (HCS). This creates a barrier when young adults need to leave the family-centered pediatric system and enter the adult, patient-centered HCS. Here we create a guide to help with the transition from pediatric to adult for patients with DS.

METHODS

Experts in Dravet syndrome flagged the main barriers in caring for adults with DS and created a 2-page transition summary guide based on their expertise and a literature review.

RESULTS

The 2-page guide addresses: DS diagnosis in children and adults; clinical manifestations, including the differences in seizures types and frequencies between children and adults with DS; the natural history of intellectual disability, behavior, gait, motor disorders and dysautonomia; a review of optimal treatments (including medications not commonly used in adult epilepsy settings such as stiripentol and fenfluramine), as well as emergency seizure management; avoidance of triggers, preventive measures, and vaccine administration in adults with DS.

CONCLUSION

Several young adults with DS are still followed by their child neurologist. This 2-page transition guide should help facilitate the transition of patients with DS to the adult HCS and should be given to families as well as adult health care providers that may not be familiar with DS.

The impact of seizure frequency on quality of life in patients with Lennox-Gastaut syndrome or Dravet syndrome

OBJECTIVES

Lennox-Gastaut syndrome (LGS) and Dravet syndrome (DS) are rare treatment-resistant epileptic encephalopathies with limited data describing the relationship between seizures and quality of life (QoL). The objective of this cross-sectional pilot study was to assess the impact on QoL of seizures and seizure-free days for the generation of utility values.

METHODS

Surveys were conducted in the UK and France, whereby patients and/or caregivers of patients with LGS, DS, or other epilepsies were asked to score health state vignettes for a hypothetical patient with LGS or DS. Respondents evaluated QoL for health states based on the number of seizures and seizure-free days per month, using a visual analog scale (VAS). Visual analog scale scores were converted to the 0-1 scale as a proxy estimate for utility values. Surveys were pilot tested and respondents were recruited from October 2018 to August 2019.

RESULTS

Patient respondents were mainly treatment-responsive (n = 43/55) whereas caregiver respondents mainly cared for patients with treatment-resistant epilepsy (n = 38/43). Most respondents and patients were aged ≥18 years. Results from LGS and DS surveys in the UK (n = 58) and France (n = 40) suggested that health states with fewer seizures and more seizure-free days had higher QoL scores for hypothetical patients. For DS, QoL scores for patient health states ranged from 0.20 (32 convulsive seizures and 4 seizure-free days/month, UK) to 0.92 (seizure-free, France). For LGS, scores ranged from 0.14 (130 drop seizures and 1 seizure-free day/month, France) to 0.83 (seizure-free, UK). In all surveys, seizure-free days had a greater impact on QoL than seizure frequency (P < 0.001).

CONCLUSIONS

Fewer seizures and additional seizure-free days improved QoL in patients with LGS or DS; seizure-free days had the greatest impact on QoL.

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.

Dravet Syndrome-The Polish Family's Perspective Study

AIM

The aim of the paper is to study the prevalence of Dravet Syndrome (DS) in the Polish population and indicate different factors other than seizures reducing the quality of life in such patients.

METHOD

A survey was conducted among caregivers of patients with DS by the members of the Polish support group of the Association for People with Severe Refractory Epilepsy DRAVET.PL. It included their experience of the diagnosis, seizures, and treatment-related adverse effects. The caregivers also completed the PedsQL survey, which showed the most important problems. The survey received 55 responses from caregivers of patients with DS (aged 2-25 years).

RESULTS

Prior to the diagnosis of DS, 85% of patients presented with status epilepticus lasting more than 30 min, and the frequency of seizures (mostly tonic-clonic or hemiconvulsions) ranged from 2 per week to hundreds per day. After the diagnosis of DS, patients remained on polytherapy (drugs recommended in DS). Before diagnosis, some of them had been on sodium channel blockers. Most patients experienced many adverse effects, including aggression and loss of appetite. The frequency of adverse effects was related to the number of drugs used in this therapy, which had an impact on the results of the PedsQL form, particularly in terms of the physical and social spheres. Intensive care unit stays due to severe status epilepticus also had an influence on the results of the PedsQL form.

CONCLUSIONS

Families must be counseled on non-pharmacologic strategies to reduce seizure risk, including avoidance of triggers that commonly induce seizures (including hyperthermia, flashing lights and patterns, sleep abnormalities). In addition to addressing seizures, holistic care for a patient with Dravet syndrome must involve a multidisciplinary team that includes specialists in physical, occupational and speech therapy, neuropsychology, social work.

Safety considerations selecting antiseizure medications for the treatment of individuals with Dravet syndrome

Introduction: Management of individuals with Dravet Syndrome has evolved significantly over the past 10 years. Progress has been made in understanding the pathophysiology, the long-term outcome and possible consequences of inappropriate therapies, new drugs have been approved by the regulatory authorities and patients and families expressed their needs beyond seizures' control.Areas covered: The authors aimed at providing an overview of the main antiseizure medications used in Dravet syndrome with a particular focus on safety considerations. As the highly active phase of seizures takes place before the age of 5 years, the characteristics of antiseizure medications in infancy and childhood have also been considered due to their impact on antiseizure medication safety.Expert opinion: Recent treatments, evaluated via randomized clinical trials, are promising in terms of efficacy and safety in individuals with DS. However, the balance between expected benefits and risks taken must be accurately assessed on an individual basis. There is a lack of data to understand the needs of patients and families, a major point particularly in this population, where the evaluation of efficacy and safety beyond seizures is difficult due to cognitive delay and behavioral disorders and where this evaluation is coming almost exclusively from caregivers.

A systematic review of adults with Dravet syndrome

Dravet Syndrome (DS) is a rare and severe infantile-onset epileptic encephalopathy. DS research focuses mainly on children. We did a systematic review, completed on January 18^th, 2021, examining the number of clinical DS studies. We show that there are 208 studies on children exclusively, 28 studies on adults exclusively, and 116 studies involving adults and children combined. This 7:1 ratio of children to adult studies exclusively shows the dearth of research that addresses long-term natural history of DS into adulthood. Through this systematic review, we examine the most up-to-date information in DS adults as it pertains to seizures, electroencephalogram, imaging, treatment, motor abnormalities, cognitive and social behavior outcomes, cardiac abnormalities, sleep disturbances, diagnosis in adults, and mortality. Overall, the frequency of seizures increases in the first decade of life and then myoclonic, atypical absences and focal seizures with impaired awareness tend to decrease in frequency or even disappear in adulthood. Adults tend to have a notable reduction in status epilepticus, especially after 30 years of age. Parkinsonian features were seen in patients as young as 19 years old and are more severe in older patients, suggesting a progression of the parkinsonian symptoms. In adulthood, patients continue to present with behavior problems, associated with a lower health-related quality of life. The leading reported cause of death in DS adults is Sudden Unexpected Death in Epilepsy (SUDEP). Further studies in older adults are needed to understand the long-term outcomes of patients with DS.

Cognitive, behavioral, and social functioning in children and adults with Dravet syndrome

AIM

The objective of the study was to delineate the cognitive, behavioral, psychological, and social functioning of individuals with Dravet syndrome.

METHOD

Cognitive, behavioral, and social functioning were assessed in patients with Dravet syndrome by comprehensive, age-appropriate standardized neuropsychological testing. Primary caregivers completed standardized measures regarding participants' behavior, psychological status, adaptive functioning, and social skills, including their involvement with intervention services.

RESULTS

The cohort comprised 45 patients, aged 2-30 years. Intellectual functioning ranged from average intellect to profound intellectual disability, with a decrease in cognitive and adaptive functioning with age. Only 6 children were able to complete the entire neuropsychological battery and showed a range of cognitive profiles. Five of 6 participants scored within the average range on Affect Recognition and 5/6 on Motor Free Visual Perception tests. Twenty-one (58%) participants had deficits in social skills and 18/27 (67%) in social communication, with 10 participants, who did not yet have a diagnosis of autism spectrum disorder (ASD), screening positive for social communication deficits. Behavioral problems were frequently reported, with attention problems in 24 (65%) and atypicality in 25 (70%). Despite this, parents reported that psychological services were the least utilized health interventions.

CONCLUSIONS

Cognitive functioning varies markedly in individuals with Dravet syndrome, with some patients demonstrating global impairment while others have a discordant neuropsychological profile. Behavioral, psychological, social problems, and ASD are common. Social deficits should be reviewed to identify those who warrant ASD assessment. Early identification of behavioral and psychological disorders and targeted use of psychological intervention are essential components of holistic care in Dravet syndrome.

Intellectual functioning and behavior in Dravet syndrome: A systematic review

BACKGROUND

Dravet syndrome (DS) is a developmental and epileptic encephalopathy with onset in the first year of life. At onset, the child displays normal development, but during the second year of life, stagnation/slowing of neurodevelopment is seen. In addition to difficulties with intellectual development, many children display behavioral problems including autistic features, and difficulties with attention and hyperactivity.

AIM

The aim of the present study was to systematically review studies that have focused on the prevalence of cognitive/developmental quotients (DQs) consistent with intellectual disability (ID), deficits in adaptive behavior, autism spectrum disorder (ASD), attention-deficit hyperactivity disorder (ADHD), and behavioral difficulties. A secondary aim was to consider possible factors associated with intellectual and behavioral outcomes in individuals with DS.

METHOD

A systematic review using PubMed and Scopus following the Preferred Reporting Items for Systematic Review (PRISMA) guidelines was conducted on the 24th of September 2019. Study quality was rated by two researchers using the National Institutes of Health (NIH) Quality assessment tools.

RESULT

Twenty-nine studies met inclusion criteria. The pooled prevalence of ID was 86% (range across studies: 50%-100%). The pooled prevalence for ASD was 31%. The mean level of adaptive behavior was more than 2 standard deviations (SDs) below average. The prevalence of behavioral difficulties on standardized instruments ranged between 37% and 100%. The only factor consistently associated with lower cognitive scores was age with older children having significantly lower cognitive scores than younger children. For behavioral difficulties, the most consistent association was with low health-related quality of life (HRQoL) with better HRQoL associated with fewer behavioral difficulties. Study quality was almost universally poor or fair - 15/29 studies were rated 'poor', 13/29 studies were 'fair', and 1 was 'good'.

DISCUSSION

The prevalence of cognitive scores consistent with ID is very high in DS. Many patients also have significant deficits in adaptive behavior highlighting that the majority of patients with DS will meet criteria for ID. The prevalence of ASD would also appear to be higher than the general population but studies show a wide range. Behavioral difficulties are common, but most studies have not used instruments adapted to patients with low intelligence quotient/DQ (IQ/DQ). No study used standardized instruments to assess ADHD. Few studies have used comprehensive statistical methods to evaluate possible factors associated with worse cognitive and behavioral outcome.

CONCLUSION

It should be routine to screen for cognitive and behavioral difficulties for all patients with DS. There is a need for more robust studies regarding intellectual and behavioral disorders in patients with DS. These should be large population-based or multinational studies that employ standardized instruments.

Dravet syndrome: Early electroclinical findings and long-term outcome in adolescents and adults

To describe the outcome of Dravet syndrome (DS) in adolescents and adults we conducted a longitudinal retrospective study of two independent cohorts of 34 adolescents (group 1) and 50 adults (group 2). In both cohorts, we collected information about genetic mutation, and semiology of seizures at onset and during disease course. At the last evaluation, we considered the following features: epilepsy (distinguishing myoclonic/complete and nonmyoclonic/incomplete phenotype), neurologic signs, intellectual disability (ID), and behavioral disorders. Moreover, in both cohorts, we performed a correlation analysis between early characteristics of the disease and the outcome of DS with regard to seizure persistence, ID, behavioral disorder, and neurologic impairment at last evaluation. Group 1 includes 22 adolescents with complete form of DS and 12 with incomplete form; group 2 includes 35 adults with complete form and 15 with incomplete form. The seizures persisted in 73.6% of adolescents and in 80% of adults, but epilepsy severity progressively decreased through age. Seizure persistence correlated with the complete phenotype and with the occurrence of reflex seizures. At last evaluation, ID was moderate or severe in 70.5% of adolescents and in 80% of adults. The most severe cognitive and motor impairment was observed in patients with persisting seizures. The severity of cognition, language, and neurologic impairment at last evaluation correlated statistically with the complete phenotype. The study confirms that the global outcome of DS is poor in most cases, albeit epilepsy severity decreases throughout adulthood. The improvement of epilepsy throughout ages is not associated with improvement in intellectual abilities and motor skills; this confirms that the unfavorable outcome is not a pure consequence of epilepsy.

Adolescent behavioral abnormalities in a Scn1a+/- mouse model of Dravet syndrome

Dravet syndrome is an intractable pediatric epilepsy associated with SCN1A mutations. In addition to having a large seizure burden and a reduced lifespan, patients with Dravet syndrome also exhibit delays in reaching normal developmental milestones in attentional, emotional, and cognitive function. These developmental delays manifest in autistic-like social withdrawal and compulsive behavior. Additionally, cognitive impairments including deficits in sensorimotor processing and memory function are present. Several mouse models utilizing heterozygous deletion of Scn1a (Scn1a^+/- mice) have been generated that recapitulate many aspects of Dravet syndrome. Studies in these mouse models of Dravet syndrome have characterized behavioral phenotypes in adult mice. In the present study, we characterized the behavioral phenotype of Scn1a^+/- mice generated by targeted deletion of Scn1a exon 1 (Scn1a^tm1Kea) during adolescence. Identifying behavioral deficits in adolescent mice would more closely model the early onset of attentional, emotional, and cognitive delays observed in patients with Dravet syndrome. The behaviors of adolescent Scn1a^+/- and wildtype (WT) mice were compared across several behavioral domains. We assessed motor function (open-field test), sociability and social recognition memory (three-chambered social preference and social interaction tests), memory function (novel object recognition, Barnes maze, fear conditioning paradigm), anxiety-related behavior (elevated plus maze and open-field thigmotaxis), startle reflex and sensorimotor gating (prepulse inhibition of startle (PPI) tests), and repetitive compulsive behavior (marble burying test). Adolescent Scn1a^+/- mice exhibited normal locomotor activity, marble burying behavior, sociability, and sensorimotor gating. However, adolescent Scn1a^+/- mice displayed increased anxiety-related thigmotactic behavior, atypical fear expression, blunted acoustic startle responses, and impaired social recognition and spatial memory. Our results show that Scn1a^+/- mice display various behavioral impairments during adolescence, which provides a foundation for testing early intervention therapies targeting developmental delays modeled in Dravet syndrome mice.

Epilepsy and brain channelopathies from infancy to adulthood

Genetic brain channelopathies result from inherited or de novo mutations of genes encoding ion channel subunits within the central nervous system. Most neurological channelopathies arise in childhood with paroxysmal or episodic symptoms, likely because of a transient impairment of homeostatic mechanisms regulating membrane excitability, and the prototypical expression of this impairment is epilepsy. Migraine, episodic ataxia and alternating hemiplegia can also occur, as well as chronic phenotypes, such as spinocerebellar ataxias, intellectual disability and autism spectrum disorder. Voltage-gated and ligand-gated channels may be involved. In most cases, a single gene may be associated with a phenotypical spectrum that shows variable expressivity. Different clinical features may arise at different ages and the adult phenotype may be remarkably modified from the syndrome onset in childhood or adolescence. Recognizing the prominent phenotypical traits of brain channelopathies is essential to perform appropriate diagnostic investigations and to provide the better care not only in the paediatric setting but also for adult patients and their caregivers. Herein, we provide an overview of genetic brain channelopathies associated with epilepsy, highlight the different molecular mechanisms and describe the different clinical characteristics which may prompt the clinician to suspect specific syndromes and to possibly establish tailored treatments.