Epilepsy, an orphan disorder within the neurodevelopmental family

Efficacy and tolerability of Brivaracetam in people with intellectual disability compared to those without intellectual disability

INTRODUCTION

In England, nearly a quarter of people with intellectual disability (PwID) have epilepsy. Though 70 % of PwID have pharmaco-resistant seizures only 10 % are prescribed anti-seizure medication (ASMs) licenced for pharmaco-resistance. Brivaracetam (BRV) licenced in 2016 has had nine post-marketing studies involving PwID. These studies are limited either by lack of controls or not looking at outcomes based on differing levels of ID severity. This study looks at evidence comparing effectiveness and side-effects in PwID to those without ID prescribed Brivaracetam (BRV).

METHODS

Pooled case note data for patients prescribed BRV (2016-2022) at 12 UK NHS Trusts were analysed. Demographics, starting and maximum dose, side-effects, dropouts and seizure frequency between ID (mild vs. moderate-profound (M/P)) and general population for a 12-month period were compared. Descriptive analysis, Mann-Whitney, Fisher's exact and logistic regression methods were employed.

RESULTS

37 PwID (mild 17 M/P 20) were compared to 102 without ID. Mean start and maximum dose was lower for PwID than non-ID. Mean maximum dose reduced slightly with ID severity. No difference was found between ID and non-ID or between ID groups (Mild vs M/P) in BRV's efficacy i.e. >50 % seizure reduction or tolerability. Mental and behavioural side-effects were more prevalent for PwID (27.0 % ID, 17.6 % no ID) but not significantly higher (P = 0.441) or associated with ID severity (p = 0.255).

CONCLUSION

This is the first study on BRV, which compares ID cohorts with differing severity and non-ID. Efficacy, tolerability and side-effects reported are similar across differing ID severity to those with no ID.

Quality of life in children with epilepsy: The role of parental mental health and sleep disruption

BACKGROUND

Parents of children with epilepsy (CWE) are at increased risk of mental health difficulties including anxiety and depression, as well as sleep difficulties. From both the child's and parent's perspectives, health-related quality of life has been shown to be strongly related to parental mental health. However, there is no literature on parental sleep as a predictor of child health-related quality of life. The role of parental variables has been assessed in relation to epilepsy-specific variables (e.g., seizure severity, anti-seizure medications) and how these relate to health-related quality of life, but prior studies have failed to consider the role of co-occurring conditions which are prevalent in CWE. The current study aims to assess how common anxiety symptoms, depression symptoms and sleep problems are in parents of CWE; and to determine the impact these parental variables as well as child co-occurring conditions have on health-related quality of life in CWE.

METHODS

33 CWE aged 4-14 years old were recruited from two hospitals and parents were asked to complete a series of questionnaires assessing both child and parental variables.

RESULTS

It was found that 33.3 % and 12.0 % of parents of CWE experienced clinically significant anxiety and depression symptoms respectively. In addition 67.9 % of parents presented with significant sleep problems. In initial analysis, parental anxiety symptoms, depression symptoms and sleep problems were all significantly predictive of child health-related quality of life. However when co-occurring child sleep problems and neurodevelopmental characteristics were included, parental variables were no longer significantly predictive of child health-related quality of life.

CONCLUSION

These results suggest that child co-occurrences mediate the relationship between parental variables and child health-related quality of life. The current data highlight the need for a systemic approach to epilepsy management and suggest that support for co-occurrences could benefit health-related quality of life for children and their parents.

Investigating the neurodevelopmental correlates of early adolescent-onset emotional problems

BACKGROUND

Emotional problems (EPs) increase sharply after mid-adolescence. Earlier EPs are associated with poorer long-term outcomes, and their underlying mechanisms may differ to later-onset EPs. Given an established relationship between ADHD, autism, and later depression, we aimed to examine associations between neurodevelopmental conditions and correlates and early adolescent-onset EPs.

METHODS

Adolescents in two UK population cohorts, Avon Longitudinal Study of Parents and Children (ALSPAC) and Millennium Cohort Study (MCS), were included. Individuals scoring >6 on the Strengths and Difficulties Questionnaire (SDQ) emotional problems subscale between ages 11-14 were defined as having early adolescent-onset EP, whilst those scoring >6 for the first time at 16-25 were defined as having later-onset EP. We tested associations between early adolescent-onset EP (total cases = 887, controls = 19,582) and ICD-10/DSM-5 neurodevelopmental conditions and known correlates, including: sex, birth complications, low cognitive ability, special educational needs (SEND), and epilepsy. Analyses were conducted separately in ALSPAC and MCS then meta-analysed.

RESULTS

In the meta-analysis of both cohorts, early adolescent-onset EPs were associated with female sex and greater likelihood of low cognitive ability, SEND, autism, ADHD, and reading difficulties. Compared to later-onset EP, early adolescent-onset EPs were associated with male sex, low cognitive ability, SEND, epilepsy, ASD, ADHD, and reading difficulties.

LIMITATIONS

A clinical definition of depression/anxiety was available only in ALSPAC, instead we primarily defined EP via questionnaires, which capture a broader phenotype.

CONCLUSIONS

Individuals with early adolescent-onset EP are likely to have a co-occurring neurodevelopmental condition. Clinicians should consider assessing for neurodevelopmental conditions in young adolescents with EPs.

Clinical characteristics of people with intellectual disability admitted to hospital with constipation: identifying possible specific high-risk factors

BACKGROUND

People with intellectual disabilities (ID) die on an average 20 years earlier to the general population. They have higher rates of multimorbidity and polypharmacy. Around 25% of people with ID report chronic constipation. The England Learning Disabilities Mortality Review found that nearly 25% of deaths identified constipation as a long-term health problem. However, the likely risk factors for constipation related harm are poorly enumerated. We sought to identify possible specific high-risk factors by examining the clinical characteristics of people with ID admitted to hospital with constipation.

METHODS

Data of people with ID admitted with constipation in two general hospitals covering a population of 1.3 million from 2017 to 2022 were reported using the STROBE guideline for cohort studies. Collected data included age, gender, intellectual disability severity, recorded medication, presenting complaint and co-morbidities. The medication anticholinergic burden was calculated using the anticholinergic burden scale. Continuous variables were summarised by mean and standard deviation if normally distributed, with categorical variables summarised by the number and percentage in each category.

RESULTS

Of 46 admissions (males 52%), 57% had moderate to profound ID, 37% had epilepsy, 41% prescribed antiseizure medication (ASM) and 45% were on laxatives. Average age was 46 years. The anticholinergic burden score mean was 2.3 and median, one.

CONCLUSIONS

We can hypothesise that people with more severe ID, suffering from epilepsy and on ASM may be more at risk of developing severe constipation. Some admissions may be avoided with earlier use of laxatives in the community.

Awareness of social care needs in people with epilepsy and intellectual disability

BACKGROUND

Nearly a quarter of people with intellectual disability (ID) have epilepsy with large numbers experiencing drug-resistant epilepsy, and premature mortality. To mitigate epilepsy risks the environment and social care needs, particularly in professional care settings, need to be met.

PURPOSE

To compare professional care groups as regards their subjective confidence and perceived responsibility when managing the need of people with ID and epilepsy.

METHOD

A multi-agency expert panel developed a questionnaire with embedded case vignettes with quantitative and qualitative elements to understand training and confidence in the health and social determinants of people with ID and epilepsy. The cross-sectional survey was disseminated amongst health and social care professionals working with people with ID in the UK using an exponential non-discriminative snow-balling methodology. Group comparisons were undertaken using suitable statistical tests including Fisher's exact, Kruskal-Wallis, and Mann-Whitney. Bonferroni correction was applied to significant (p < 0.05) results. Content analysis was conducted and relevant categories and themes were identified.

RESULTS

Social and health professionals (n = 54) rated their confidence to manage the needs of people with ID and epilepsy equally. Health professionals showed better awareness (p < 0.001) of the findings/recommendations of the latest evidence on premature deaths and identifying and managing epilepsy-related risks, including the relevance of nocturnal monitoring. The content analysis highlighted the need for clearer roles, improved care pathways, better epilepsy-specific knowledge, increased resources, and better multi-disciplinary work.

CONCLUSIONS

A gap exists between health and social care professionals in awareness of epilepsy needs for people with ID, requiring essential training and national pathways.

Antiseizure medications prescribing for behavioural and psychiatric concerns in adults with an intellectual disability living in England

Antiseizure medications (ASMs) are the second most widely prescribed psychotropic for people with intellectual disabilities in England. Multiple psychotropic prescribing is prevalent in almost half of people with intellectual disabilities on ASMs. This analysis identifies limited evidence of ASM benefit in challenging behaviour management and suggests improvements needed to inform clinical practice.

The role of common genetic variation in presumed monogenic epilepsies

BACKGROUND

The developmental and epileptic encephalopathies (DEEs) are the most severe group of epilepsies which co-present with developmental delay and intellectual disability (ID). DEEs usually occur in people without a family history of epilepsy and have emerged as primarily monogenic, with damaging rare mutations found in 50% of patients. Little is known about the genetic architecture of patients with DEEs in whom no pathogenic variant is identified. Polygenic risk scoring (PRS) is a method that measures a person's common genetic burden for a trait or condition. Here, we used PRS to test whether genetic burden for epilepsy is relevant in individuals with DEEs, and other forms of epilepsy with ID.

METHODS

Genetic data on 2,759 cases with DEEs, or epilepsy with ID presumed to have a monogenic basis, and 447,760 population-matched controls were analysed. We compared PRS for 'all epilepsy', 'focal epilepsy', and 'genetic generalised epilepsy' (GGE) between cases and controls. We performed pairwise comparisons between cases stratified for identifiable rare deleterious genetic variants and controls.

FINDINGS

Cases of presumed monogenic severe epilepsy had an increased PRS for 'all epilepsy' (p<0.0001), 'focal epilepsy' (p<0.0001), and 'GGE' (p=0.0002) relative to controls, which explain between 0.08% and 3.3% of phenotypic variance. PRS was increased in cases both with and without an identified deleterious variant of major effect, and there was no significant difference in PRS between the two groups.

INTERPRETATION

We provide evidence that common genetic variation contributes to the aetiology of DEEs and other forms of epilepsy with ID, even when there is a known pathogenic variant of major effect. These results provide insight into the genetic underpinnings of the severe epilepsies and warrant a shift in our understanding of the aetiology of the DEEs as complex, rather than monogenic, disorders.

FUNDING

Science foundation Ireland, Human Genome Research Institute; National Heart, Lung, and Blood Institute; German Research Foundation.

Modelling the neurodevelopmental pathogenesis in neuropsychiatric disorders. Bioactive kynurenines and their analogues as neuroprotective agents-in celebration of 80th birthday of Professor Peter Riederer

Following introduction of the monoamine oxidase type B inhibitor selegiline for the treatment of Parkinson's disease (PD), discovery of the action mechanism of Alzheimer's disease-modifying agent memantine, the role of iron in PD, and the loss of electron transport chain complex I in PD, and development of the concept of clinical neuroprotection, Peter Riederer launched one of the most challenging research project neurodevelopmental aspects of neuropsychiatric disorders. The neurodevelopmental theory holds that a disruption of normal brain development in utero or during early life underlies the subsequent emergence of neuropsychiatric symptoms during later life. Indeed, the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition and the International Classification of Diseases, 11th Revision categorize autism spectrum disorder and attention deficit hyperactivity disorder in neurodevelopmental disorders (NDDs). More and more evidence, especially from preclinical studies, is revealing that neurodevelopmental pathology is not limited to the diagnostic class above, but also contributes to the development of other psychiatric disorders such as schizophrenia, bipolar disorder, and obsessive-compulsive disorder as well as neurodegenerative diseases such as PD and Huntington's disease. Preclinical animal research is taking a lead in understanding the pathomechanisms of NDDs, searching for novel targets, and developing new neuroprotective agents against NDDs. This narrative review discusses emerging evidence of the neurodevelopmental etiology of neuropsychiatric disorders, recent advances in modelling neurodevelopmental pathogenesis, potential strategies of clinical neuroprotection using novel kynurenine metabolites and analogues, and future research direction for NDDs.

Perspective: Chicken Models for Studying the Ontogenetic Origin of Neuropsychiatric Disorders

Nutrients and xenobiotics cross the blood–placenta barrier, potentially depositing in the fetal brain. The prenatal exposure affects the neuroendocrine and microbial development. The mechanism underlying maternal risk factors reprograming the microbiota–gut–brain axis with long-term effects on psychosocial behaviors in offspring is not clear. In humans, it is not possible to assess the nutrient or xenobiotic deposition in the fetal brain and gastrointestinal system for ethical reasons. Moreover, the maternal–fetal microbe transfer during gestation, natural labor, and breast-feeding constitutes the initial gut microbiome in the progeny, which is inevitable in the most widely utilized rodent models. The social predisposition in precocial birds, including chickens, provides the possibility to test behavioral responses shortly after being hatched. Hence, chickens are advantageous in investigating the ontogenetic origin of behaviors. Chicken embryos are suitable for deposition assessment and mechanistic study due to the accessibility, self-contained development, uniform genetic background, robust microbiota, and easy in vivo experimental manipulation compared to humans and rodents. Therefore, chicken embryos can be used as an alternative to the rodent models in assessing the fetal exposure effect on neurogenesis and investigating the mechanism underlying the ontogenetic origin of neuropsychiatric disorders.

Deep phenotyping and whole-exome sequencing improved the diagnostic yield for nuclear pedigrees with neurodevelopmental disorders

Background

Neurodevelopmental disorders, a group of early‐onset neurological disorders with significant clinical and genetic heterogeneity, remain a diagnostic challenge for clinical genetic evaluation. Therefore, we assessed the diagnostic yield by combining standard phenotypes and whole‐exome sequencing in families with these disorders that were “not yet diagnosed” by the traditional testing methods.

Methods

Using a standardized vocabulary of phenotypic abnormalities from human phenotype ontology (HPO), we performed deep phenotyping for 45 “not yet diagnosed” pedigrees to characterize multiple clinical features extracted from Chinese electronic medical records (EMRs). By matching HPO terms with known human diseases and phenotypes from model organisms, together with whole‐exome sequencing data, we prioritized candidate mutations/genes. We made probable genetic diagnoses for the families.

Results

We obtained a diagnostic yield of 29% (13 out of 45) with probably genetic diagnosis, of which compound heterozygosity and de novo mutations accounted for 77% (10/13) of the diagnosis. Of note, these pedigrees are accompanied by a more significant number of non‐neurological features.

Conclusions

Deep phenotyping and whole‐exome sequencing improve the etiological evaluation for neurodevelopmental disorders in the clinical setting.

A review of the pharmacotherapeutic considerations for managing epilepsy in people with autism

INTRODUCTION

Autism, like other neurodevelopmental disorders (NDDs), has a strong association with epilepsy. There are known common genetic pathways in both autism and epilepsy. There are also specific genetic syndromes associated with both complex epilepsy and the autism phenotype.

AREAS COVERED

This review explores the evidence for common genetic etiologies and pathophysiological pathways in relation to both epilepsy and autism. Autism with comorbid epilepsy are associated with a high prevalence of medical and psychiatric comorbidities. This paper discusses how this influences assessment, treatment, and outcomes. The evidence for the treatment of specific seizure types in the context of NDDs is also examined alongside clinical commentary.

EXPERT OPINION

Despite the strong association, there is a limited evidence base to support the efficacy and tolerability of anti-seizure medications specifically in autism, with no Level 1 evidence or National Guidance available. Autism and epilepsy should be approached under a NDD model with cautious introduction and titration of anti-seizure medication. Alongside this, there is evidence to support a move toward precision medicine in specific genetic syndromes such as Tuberous Sclerosis Complex and other genetic seizure disorders. The first-line treatments that should be considered for focal seizures include carbamazepine, lamotrigine, and levetiracetam.

The Genetic Diagnosis of Ultrarare DEEs: An Ongoing Challenge

Epileptic encephalopathies (EEs) and developmental and epileptic encephalopathies (DEEs) are a group of severe early-onset neurodevelopmental disorders (NDDs). In recent years, next-generation equencing (NGS) technologies enabled the discovery of numerous genes involved in these conditions. However, more than 50% of patients remained undiagnosed. A major obstacle lies in the high degree of genetic heterogeneity and the wide phenotypic variability that has characterized these disorders. Interpreting a large amount of NGS data is also a crucial challenge. This study describes a dynamic diagnostic procedure used to investigate 17 patients with DEE or EE with previous negative or inconclusive genetic testing by whole-exome sequencing (WES), leading to a definite diagnosis in about 59% of participants. Biallelic mutations caused most of the diagnosed cases (50%), and a pathogenic somatic mutation resulted in 10% of the subjects. The high diagnostic yield reached highlights the relevance of the scientific approach, the importance of the reverse phenotyping strategy, and the involvement of a dedicated multidisciplinary team. The study emphasizes the role of recessive and somatic variants, new genetic mechanisms, and the complexity of genotype–phenotype associations. In older patients, WES results could end invasive diagnostic procedures and allow a more accurate transition. Finally, an early pursued diagnosis is essential for comprehensive care of patients, precision approach, knowledge of prognosis, patient and family planning, and quality of life.

People with epilepsy and intellectual disability: More than a sum of two conditions

BACKGROUND

Around 25% of people with Intellectual Disability (PwID) have comorbid epilepsy with seizures in up to two-thirds being drug-resistant. Little is known of the general characteristics and prescribing practices to this population.

AIM

Describe and compare characteristics of two cohorts of PwID and epilepsy in two different countries to inform clinical practice better.

METHOD

An explorative, retrospective, case-note review in a specialist ID community service in England and in an expert center for PwID and epilepsy in the Netherlands was conducted. Information on ID severity, medical/behavioral/psychiatric/neurodevelopmental/genetic comorbidities, psychotropic, and antiepileptic drugs (AEDs) for each cohort was collected.

FINDINGS

The English cohort consisted of 167 people (98 males; age range 18-73 years; mild/moderate ID- 35%) and the Dutch cohort of 189 people (111 males; age range 18-85 years; mild/moderate ID - 51%). The two cohorts were comparable in their baseline characteristics. The Dutch had higher rates of physical comorbidity, but less mental or behavioral disorders and were more likely to be on anti-psychotic medication. The mean dosages between three most common AEDs prescribed were similar. The most frequently prescribed drug in both centers is valproate. Three-quarters of the Dutch were on three or more AEDs compared to a third in the English cohort.

CONCLUSIONS

Structured description of the characteristics, differences, and commonalities of PwID, treatment, and services of both countries is presented. This is the first real-world study to reveal unique characteristics of managing epilepsy for a complex ID population. In particular, it highlights the considerable comorbid psychiatric burden and psychotropic prescribing.

Eslicarbazepine acetate response in intellectual disability population versus general population

BACKGROUND

A quarter of people with intellectual disability (ID) have epilepsy, compared to approximately one in a hundred across the general population. Evidence for the safe and effective prescribing of antiepileptic drugs (AEDs) for those with ID is, however, limited.

AIMS OF STUDY

This study seeks to strengthen the research evidence around Eslicarbazepine Acetate (ESL), a new AED, by comparing response of individuals with ID to those from the general population who do not have ID.

METHODS

A single data set was created through retrospective data collection from English and Welsh NHS Trusts. The UK-based Epilepsy Database Research Register (Ep-ID) data collection and analysis method were used.

RESULTS

Data were collected for 93 people (36 ID and 57 'no ID'). Seizure improvement of '>50%' was higher at 12 months for 'no ID' participants (56%), compared to ID participants (35%). Retention rates were slightly higher for those with ID (56% compared to 53%). Neither difference was significant.

CONCLUSIONS

Tolerance and Efficacy for ID and 'no ID' people in our data set were similar. Seizure improvement and retention rates were slightly lower than that found in other European data sets, but findings strengthen the evidence for the use of ESL in the ID population.