Evolution and course of early life developmental encephalopathic epilepsies: Focus on Lennox-Gastaut syndrome

Clinical features and underlying etiology of children with Lennox-Gastaut syndrome

OBJECTIVE

Lennox-Gastaut Syndrome (LGS) is characterized by the presence of multiple seizure types and encompasses a heterogenous group of etiologies. The aim of our study was to evaluate the etiological profile of LGS and investigate seizure outcomes based on different clinical variables.

METHODS

The clinical features, neuroimaging findings, genetic testing and other testing results of LGS patients were systematically reviewed. The identifiable etiology was categorized as either acquired or nonacquired. Univariate and multivariate regression analyses were performed to explore the association between clinical variables and seizure outcome at the last follow-up.

RESULTS

We enrolled 156 patients diagnosed with LGS, of whom 66% were male. The mean age of patients was 34.2 months and the median follow-up duration was 29.5 months (interquartile range = 14-56.25 months). The initial seizure type was epileptic spasm in 61 patients, among which 33 of them met the criteria for infantile epileptic spasm syndrome. All patients underwent neuroimaging test, with 25% falling into the acquired structural category. Etiology could be identified in 84 individuals, including pathogenetic variants found in 34 out of 117 patients with nonacquired etiology. CHD2 mutations were most frequently observed among these pathogenetic variants. At the last follow-up, favorable outcomes were observed in 27 patients. The identification of etiology emerged as a significant determinant influencing LGS outcome; specifically, patients with unknown etiology had a higher likelihood of experiencing favorable outcomes compared to those with known cause (p = 0.041). Early onset age and longer epilepsy duration significantly increased the odds of an unfavorable outcome (p = 0.006 and 0.024).

SIGNIFICANCE

We present novel data on the clinical and etiological spectrum of LGS, with determined etiology observed in over half of the patients. Epileptic spasms were found to be more prevalent than tonic seizures as seizure onset types in LGS. The presence of a known etiology, earlier age at onset, and longer duration of epilepsy were associated with a poorer long-term epileptological outcome.

Pediatric epilepsy syndromes with associated developmental impairment

In 2022, the International League Against Epilepsy revised their classification of epilepsy syndromes for clinicians to better understand the relationships between different epilepsy syndromes, their underlying causes, and their associated developmental and behavioral features. This review highlights portions of the current classification with an emphasis on epilepsy syndromes that readily present with developmental challenges and provides a unique framework, based on electroencephalography, to easily identify and understand these syndromes. Included in this review are a helpful categorization scheme with visual aid, descriptions of updated epilepsy syndromes, figures of relevant identifiers of syndrome and information regarding future directions toward treatment and research. Covered syndromes include developmental and epileptic encephalopathy, Dravet syndrome, Rasmussen syndrome, and infantile epileptic spasm syndrome, among others. WHAT THIS PAPER ADDS: The revised epilepsy syndrome classification by the International League Against Epilepsy aims to improve the outcomes for children with epilepsy. The electroencephalography features of epilepsy syndromes are grouped based on a categorization model. This model allows clinicians to understand overlapping phenotypes and aid with both identification and diagnosis.

A quantitative cross-sectional study of the burden of caring for patients with Lennox-Gastaut syndrome, Dravet syndrome, and tuberous sclerosis complex-associated epilepsy in Japan

INTRODUCTION

Lennox-Gastaut syndrome (LGS), Dravet syndrome (DS), and tuberous sclerosis complex (TSC)-associated epilepsy are rare conditions associated with severe childhood-onset epilepsy. Caregivers play a critical role in the patients' care and may experience significant psychosocial and socioeconomic burden. This cross-sectional study determined the burden of caring for patients with these rare epilepsy conditions in Japan.

METHODS

A quantitative online survey was used to assess patients' and caregivers' characteristics and the caregivers' emotional state, among others. Several validated questionnaires were used: the Hospital Anxiety and Depression Scale (HADS; 0-21 score) assessed the caregivers' emotional wellbeing, the Pediatric Quality of Life Inventory Family Impact Module (PedsQL FIM; 0-100 score) assessed the health-related quality of life (HRQoL) of the caregivers and their families, and the Work Productivity and Activity Impairment General Health (WPAI:GH; 0-100 % score) questionnaire assessed work productivity.

RESULTS

A total of 36 caregivers responded (median [interquartile range (IQR)] age 43.5 [39.5, 48.3] years; 33/36 [92 %] female; 13/36 [36 %] working part-time and 13/36 [36 %] not working). Participants cared for 7/36 (19 %), 19/36 (53 %), and 10/36 (28 %) patients with LGS, DS, and TSC, respectively (median [IQR] age, 11.0 [6.8, 16.3] years; age at first seizure, 0 [0, 0] years). Patients received a median (IQR) of 4 (3, 5) treatment drug types. Patients experienced median (IQR) 3.0 (0, 21.0) epileptic seizures in the previous week; 28/36 (78 %) had severe intellectual disabilities, and 34/36 (94 %) had developmental delays. Caregivers reported stress (17/36 [47 %]), sleep problems (13/36 [36 %]), and anxiety (12/36 [33 %]). They spent a median (IQR) of 50.0 (17.5, 70.0) hours caregiving in the previous week, with 3.0 (1.0, 11.0) hours of seizure-specific care. Caregivers reported that their lives would be easier with a median (IQR) of 1.5 (0, 5.0) hours fewer per week caring for patients during/following seizures. Median HADS scores were 9.5 ('suspected anxiety diagnosis') and 7.5 ('no depression') for caregivers, and PedsQL FIM Total median score was 60.1, indicating HRQoL impairment for the caregiver and their family. WPAI:GH scores for paid workers indicated important work impairment. Higher caregiving hours (≥ 21 h vs. < 21 h in the previous week) resulted in higher caregiver burden as indicated by the HADS Total score (p = 0.0062) and PedsQL FIM Total score (p = 0.0007).

CONCLUSIONS

Caregivers of patients with LGS, DS, or TSC in Japan experience a significant time burden, reduced HRQoL, and high level of work/activity impairment. Caregivers provide round-the-clock care to patients and rely on family and specialized caring services to help manage the increased caregiving time, which tends to be associated with greater emotional burden and HRQoL impact.

A comprehensive systematic literature review of the burden of illness of Lennox-Gastaut syndrome on patients, caregivers, and society

Fully elucidating the burden that Lennox-Gastaut syndrome (LGS) places on individuals with the disease and their caregivers is critical to improving outcomes and quality of life (QoL). This systematic literature review evaluated the global burden of illness of LGS, including clinical symptom burden, care requirements, QoL, comorbidities, caregiver burden, economic burden, and treatment burden (PROSPERO ID: CRD42022317413). MEDLINE, Embase, and the Cochrane Library were searched for articles that met predetermined criteria. After screening 1442 deduplicated articles and supplementary manual searches, 113 articles were included for review. A high clinical symptom burden of LGS was identified, with high seizure frequency and nonseizure symptoms (including developmental delay and intellectual disability) leading to low QoL and substantial care requirements for individuals with LGS, with the latter including daily function assistance for mobility, eating, and toileting. Multiple comorbidities were identified, with intellectual disorders having the highest prevalence. Although based on few studies, a high caregiver burden was also identified, which was associated with physical problems (including fatigue and sleep disturbances), social isolation, poor mental health, and financial difficulties. Most economic analyses focused on the high direct costs of LGS, which arose predominantly from medically treated seizure events, inpatient costs, and medication requirements. Pharmacoresistance was common, and many individuals required polytherapy and treatment changes over time. Few studies focused on the humanistic burden. Quality concerns were noted for sample representativeness, disease and outcome measures, and reporting clarity. In summary, a high burden of LGS on individuals, caregivers, and health care systems was identified, which may be alleviated by reducing the clinical symptom burden. These findings highlight the need for a greater understanding of and better definitions for the broad spectrum of LGS symptoms and development of treatments to alleviate nonseizure symptoms.

A systematic literature review on the global epidemiology of Dravet syndrome and Lennox-Gastaut syndrome: Prevalence, incidence, diagnosis, and mortality

Dravet syndrome (DS) and Lennox-Gastaut syndrome (LGS) are rare developmental and epileptic encephalopathies associated with seizure and nonseizure symptoms. A comprehensive understanding of how many individuals are affected globally, the diagnostic journey they face, and the extent of mortality associated with these conditions is lacking. Here, we summarize and evaluate published data on the epidemiology of DS and LGS in terms of prevalence, incidence, diagnosis, genetic mutations, and mortality and sudden unexpected death in epilepsy (SUDEP) rates. The full study protocol is registered on PROSPERO (CRD42022316930). After screening 2172 deduplicated records, 91 unique records were included; 67 provided data on DS only, 17 provided data on LGS only, and seven provided data on both. Case definitions varied considerably across studies, particularly for LGS. Incidence and prevalence estimates per 100 000 individuals were generally higher for LGS than for DS (LGS: incidence proportion = 14.5-28, prevalence = 5.8-60.8; DS: incidence proportion = 2.2-6.5, prevalence = 1.2-6.5). Diagnostic delay was frequently reported for LGS, with a wider age range at diagnosis reported than for DS (DS, 1.6-9.2 years; LGS, 2-15 years). Genetic screening data were reported by 63 studies; all screened for SCN1A variants, and only one study specifically focused on individuals with LGS. Individuals with DS had a higher mortality estimate per 1000 person-years than individuals with LGS (DS, 15.84; LGS, 6.12) and a lower median age at death. SUDEP was the most frequently reported cause of death for individuals with DS. Only four studies reported mortality information for LGS, none of which included SUDEP. This systematic review highlights the paucity of epidemiological data available for DS and especially LGS, demonstrating the need for further research and adoption of standardized diagnostic criteria.

Diagnosis of Lennox-Gastaut syndrome and strategies for early recognition

INTRODUCTION

Lennox Gastaut syndrome (LGS) as an electroclinical diagnosis has been utilized as a clinical entity for more than 70 years. However, with the recognition of other distinct electroclinical epilepsy syndromes, no consistent single etiology, and the variability of criteria used in clinical trials, the clinical utility of such a diagnosis has been questioned. Recently, the International League Against Epilepsy for the first time defined diagnostic criteria for epilepsy syndromes, thereby allowing consistent language and inclusion criteria to be utilized.

AREAS COVERED

Recent diagnostic criteria for syndrome diagnosis are explored as defined by the International League Against Epilepsy, with further literature reviewed to highlight relevant features, and differential diagnosis explored.

EXPERT OPINION

Developmental and Epileptic Encephalopathy (DEE) is an overall term that may be descriptive of many different epilepsies, most of early onset, whether electroclinically or etiologically defined, of which LGS is one. Although we have moved forward in defining an increasing number of etiologically specific syndromes, this to date remains a minority of the DEEs. Although there is progress with precision medicine targeted at specific causes, the term LGS still remains useful as a diagnosis in defining treatment options, as well as overall prognosis.

Therapeutic outcome of patients with Lennox-Gastaut syndrome with mitochondrial respiratory chain complex I deficiency

Background

Lennox-Gastaut syndrome (LGS), a severe developmental epileptic encephalopathy, has various underlying causes. Mitochondrial respiratory chain complex I (MRC I) deficiency is an important cause of metabolic disorders such as mitochondrial dysfunction that can compromise brain function, thereby causing intractable epilepsy, including LGS. Thus, it can be expected that the presence or absence of MRC I deficiency may affect the treatment outcome of patients with LGS.

Objectives

In this retrospective study, we aimed to investigate differences in the epilepsy characteristics and treatment outcomes between patients with LGS with and without MRC I deficiency.

Methods

We retrospectively reviewed the medical records of 92 patients with LGS. We divided 68 patients with LGS according to the presence (n = 30) or absence (n = 38) of MRC I deficiency and compared their epilepsy characteristics.

Results

Generalized tonic and drop seizures were significantly worse in patients with LGS and MRC I deficiency than in those without MRC I deficiency group at the 1-year follow-up (p < 0.001) and final follow-up 1 (p < 0.001). Patients with LGS and MRC I deficiency had significantly fewer electroencephalogram (EEG) improvements compared to those without MRC I deficiency at the 1-year follow-up (p = 0.031). Additionally, in the final follow-up period, patients with LGS and MRC I deficiency had significantly less improvement in EEG findings compared to patients without MRC I deficiency (p < 0.001).

Conclusion

The overall treatment prognosis-in terms of improvement in traumatic generalized tonic seizure, drop seizure, and EEG findings-is worse in patients with LGS and MRC I deficiency than that in patients with LGS but without MRC I deficiency. Additional and targeted treatment is required to treat LGS with MRC I deficiency.

Evaluating fenfluramine hydrochloride as an oral solution for the treatment of seizures associated with Lennox-Gastaut syndrome

INTRODUCTION

Lennox-Gastaut syndrome (LGS) is a severe childhood-onset developmental and epileptic encephalopathy characterized by treatment-refractory seizures, including tonic/atonic 'drop' seizures, and intellectual impairment and slow spike-wave discharges on the electroencephalogram. Fenfluramine, previously prescribed as a weight-loss drug but then withdrawn, has recently been approved in the US, EU, and UK for the adjunct treatment of seizures associated with LGS.

AREAS COVERED

The authors review the efficacy and safety findings from clinical trials of fenfluramine in LGS. The authors then discuss the evidence for adverse effects that may be of particular concern to fenfluramine, namely cardiac abnormalities, and weight loss, in the context of the use of fenfluramine for the treatment of the refractory seizures in LGS.

EXPERT OPINION

Fenfluramine has demonstrated efficacy in reducing the frequency of seizures in LGS, notably drop seizures, in short-term and long-term clinical trials. Valvular heart disease and pulmonary hypertension have not been reported at the low doses (≤26 mg/day) used in these studies, however, data are limited. Due to its novel mechanism of action, fenfluramine may be of benefit in LGS which has not responded adequately to other antiseizure medications. However, none of these medications, including fenfluramine, achieves the ultimate goal of seizure freedom in most cases.

Interrater reliability of interictal EEG waveforms in Lennox-Gastaut Syndrome

OBJECTIVE

Identification of EEG waveforms is critical for diagnosing Lennox-Gastaut Syndrome (LGS) but is complicated by the progressive nature of the disease. Here, we assess the interrater reliability (IRR) among pediatric epileptologists for classifying EEG waveforms associated with LGS.

METHODS

A novel automated algorithm was used to objectively identify epochs of EEG with transient high power, which were termed events of interest (EOIs). The algorithm was applied to EEG from 20 LGS subjects and 20 healthy controls during NREM sleep, and 1350 EOIs were identified. Three raters independently reviewed the EOIs within isolated 15-second EEG segments in a randomized, blinded fashion. For each EOI, the raters assigned a waveform label (spike and slow wave, generalized paroxysmal fast activity, seizure, spindle, vertex, muscle, artifact, nothing, or other) and indicated the perceived subject type (LGS or control).

RESULTS

Labeling of subject type had 85% accuracy across all EOIs and an IRR of κ =0.790, suggesting that brief segments of EEG containing high-power waveforms can be reliably classified as pathological or normal. Waveform labels were less consistent, with κ =0.558, and the results were highly variable for different categories of waveforms. Label mismatches typically occurred when one reviewer selected "nothing," suggesting that reviewers had different thresholds for applying named labels.

SIGNIFICANCE

Classification of EEG waveforms associated with LGS has weak IRR, due in part to varying thresholds applied during visual review. Computational methods to objectively define EEG biomarkers of LGS may improve IRR and aid clinical decision-making.

Patient family engagement and partnership: Pilot survey results in assessing behavior, communication, and quality of life in children with Lennox-Gastaut syndrome and other drug-resistant epilepsy

OBJECTIVES

Lennox-Gastaut Syndrome (LGS) and other drug-resistant epilepsy (DRE) can impact behavior, communication, and quality of life (QoL). In collaboration with community engagement efforts with the Lennox-Gastaut Syndrome Foundation (LGSF), we aimed to gain an initial snapshot of patient and family perspectives and experiences with evaluation of behavior, communication, and QoL.

METHODS

A cross-sectional survey was conducted to collect self-reported information from caregivers of children with LGS and other DRE regarding their perspectives and experiences with healthcare providers' evaluation of behavior, communication, and QoL. The survey tool was developed by the study investigators in partnership with the LGS Foundation and had diffused to caregivers online by epilepsy advocacy groups including the Pediatric Epilepsy Surgery Alliance (PESA). Responses were analyzed. Descriptive statistics were calculated. The survey asked for caregiver perspectives and assessed which instruments the caregivers had previously been given for measuring these domains.

RESULTS

Responses from 245 caregivers were included, with 132 (54%) caregivers of an individual with LGS and 113 (46%) caregivers of an individual with non-LGS related DRE. Respondents reported that 66% of their loved ones had undergone epilepsy-related surgery. Over 90% agreed that measuring behavior, communication, and QoL was important, but fewer than half felt that their healthcare providers evaluated these domains well. LGS caregivers largely shared non-LGS caregivers' perspectives; however, they reported more frequently that communication was not evaluated enough. Barriers to measuring these domains included a lack of good surveys (developmentally appropriate and specific to the type of epilepsy) or not receiving any survey instruments for these domains during clinic appointments. Caregivers play a crucial role for individuals with DRE, and their input is essential in identifying challenges and needs. Caregivers believe that measuring behavior, communication, and quality of life is important, and most of them feel that their loved ones are not adequately evaluated during their healthcare encounters. There is a need for appropriately scaled survey instruments to measure areas of importance for patients and caregivers, as well as incorporation of these outcomes in the healthcare discussion.

Epidemiology of Developmental and Epileptic Encephalopathy and of Intellectual Disability and Epilepsy in Children

BACKGROUND AND OBJECTIVES

We aimed to determine the population-based cumulative incidence and prevalence of developmental and epileptic encephalopathies (DEEs) and intellectual disability and epilepsy (ID+E) in children. We analyzed the cumulative incidence of specific epilepsy syndromes.

METHODS

Children younger than 16 years with a DEE or ID+E were ascertained using EEG records from 2000 to 2016 in the Wellington region of New Zealand. Epilepsy syndromes were diagnosed on medical record and EEG review. Point prevalence and cumulative incidence for children with epilepsy and developmental impairment, DEE and ID+E were calculated. Cumulative incidence for each epilepsy syndrome was calculated.

RESULTS

The cohort comprised 235 children (58% male) with developmental impairment and epilepsy, including 152 (65%) with DEE and 83 (35%) with ID+E. The median age of seizure onset was 15.4 months (range day 1-15 years). The median follow-up from seizure onset was 7.9 years (range 0-18.2 years). Point prevalence for the broad group of children with epilepsy and developmental impairment was 175/100,000 children (95% CI 149-203; DEE 112 and ID+E 63/100,000 children). Cumulative incidence for DEE was 169/100,000 children (95% CI 144-199) and that for ID+E was 125/100,000 children (95% CI 95.4-165). Cumulative incidence per 100,000 children was as follows: infantile epileptic spasms syndrome 58.2 (95% CI 45.0-75.3), epilepsy with myoclonic-atonic seizures 16.4 (95% CI 9.69-27.7), Lennox-Gastaut syndrome 13.2 (95% CI 4.1-41.9), and Dravet syndrome 5.1 (95% CI 2.1-12.2). Fifty/152 (33%) of children with DEE and 70/83 (84%) with ID+E could not be diagnosed with a known epilepsy syndrome.

DISCUSSION

Epilepsy and developmental impairment before the age of 16 years occurs in 1 in 340 children, with 1 in 590 having a DEE and 1 in 800 having ID+E. These individuals require significant health and community resources; therefore, these data will inform complex health service and education planning. Epidemiologic studies have focused on early childhood-onset DEEs. These do not fully reflect the burden of these disorders because 27% of DEEs and 70% of ID+E begin later, with seizure onset after the age of 3 years. Understanding the cumulative incidence of specific syndromes together with the broad group of DEEs is essential for the planning of therapeutic trials. Given trials focus on specific syndromes, there is a risk that effective therapies will not be developed for one-third of children with DEE.

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

INTRODUCTION

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

AREAS COVERED

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

EXPERT OPINION

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

Development of localized interictal epileptiform discharges following vagus nerve stimulation for lennox-gastaut syndrome: a case report

Background

Lennox-gastaut syndrome (LGS) is an epileptic encephalopathy often associated with behavioral and psychiatric disorders. Vagus nerve stimulation (VNS) has been approved effective for LGS treatment. Surgical resection is also an option for LGS patients with focal pathology, offering a high probability of seizure control. However, it is challenging to accurately localize the seizure focus.

Case presentation

The case presented here is a 19-year-old male with a 16-year history of epilepsy with comorbid severe cognitive and psychiatric disorders. He was diagnosed with LGS due to generalized slow spike-wave discharges and multiple seizure types. He was treated with VNS in 2017 at the age of 15. After that, the frequency of the short tonic seizures decreased from 4–5 times per day to 2–5 times per year, and the generalized tonic–clonic seizure pattern did not recur, which had a frequency of 2–4 times per month before the surgery. In 2019, the generalized abnormal interictal epileptiform discharges changed to be localized in the right frontal–temporal lobe at the age of 17 years (2019).

Conclusions

This case report suggested that the generalized epileptiform discharges evolve into localized discharges after VNS treatment, which may help reveal the primary seizure focus for resection surgery in patients with LGS.

Personalized structural biology reveals the molecular mechanisms underlying heterogeneous epileptic phenotypes caused by de novo KCNC2 variants

Whole-exome sequencing (WES) in the clinic has identified several rare monogenic developmental and epileptic encephalopathies (DEE) caused by ion channel variants. However, WES often fails to provide actionable insight for rare diseases, such as DEEs, due to the challenges of interpreting variants of unknown significance (VUS). Here, we describe a "personalized structural biology" (PSB) approach that leverages recent innovations in the analysis of protein 3D structures to address this challenge. We illustrate this approach in an Undiagnosed Diseases Network (UDN) individual with DEE symptoms and a de novo VUS in KCNC2 (p.V469L), the Kv3.2 voltage-gated potassium channel. A nearby KCNC2 variant (p.V471L) was recently suggested to cause DEE-like phenotypes. Computational structural modeling suggests that both affect protein function. However, despite their proximity, the p.V469L variant is likely to sterically block the channel pore, while the p.V471L variant is likely to stabilize the open state. Biochemical and electrophysiological analyses demonstrate heterogeneous loss-of-function and gain-of-function effects, as well as differential response to 4-aminopyridine treatment. Molecular dynamics simulations illustrate that the pore of the p.V469L variant is more constricted, increasing the energetic barrier for K+ permeation, whereas the p.V471L variant stabilizes the open conformation. Our results implicate variants in KCNC2 as causative for DEE and guide the interpretation of a UDN individual. They further delineate the molecular basis for the heterogeneous clinical phenotypes resulting from two proximal pathogenic variants. This demonstrates how the PSB approach can provide an analytical framework for individualized hypothesis-driven interpretation of protein-coding VUS.

Perampanel as adjuvant treatment in epileptic encephalopathies: A multicenter study in routine clinical practice

OBJECTIVE

Developmental and epileptic encephalopathies (DEEs) are a heterogeneous group of syndromes, including Lennox-Gastaut syndrome (LGS), which are refractory to multiple therapies. Perampanel efficacy has been reported in LGS but further real-world evidence is needed in DEEs.

METHODS

A multicenter, retrospective, 1-year observational study in patients with DEEs on adjuvant perampanel treatment was conducted to assess perampanel safety and effectiveness in this type of patients in a real-world setting. Seizure types [focal onset seizures (FOS), generalized tonic-clonic seizures (GTCS), tonic seizures (TS), atonic seizures (AtS), atypical absences (AA), and myoclonic seizures (MS)] and seizure clusters were divided in different frequency groups: daily, weekly, and monthly seizures, and absent or seizure freedom. Patients could have more than one seizure type. For each frequency group, group change and seizure freedom were analyzed.

RESULTS

Eighty-seven patients diagnosed with DEEs (45 males) of median age 22 [1-70] years were included. The most frequent DEEs were LGS (35.6%) and Lennox-like syndrome (37.9%). At baseline 20 patients had three to five types of seizures, 36 patients had two types of seizures and 31 patients had one predominant type of seizure. The mean number of seizure types per patient at baseline was 2.12 ± 0.97 which was reduced to 1.62 ± 0.91 at 12 months (p < 0.001). Overall, 51.7% of patients had a significant improvement in at least one seizure type. At baseline, 45 patients had GTCS, 42 FOS, 41 TS, 18 AA, 16 AtS, 11 MS, and 30 seizures clusters. Seizure freedom for each specific type at 12 months was significantly achieved by 35% of patients with GTCS (p < 0.001), 17% (p = 0.016) with TS and 37% with seizure clusters (p < 0.001). Patients achieved seizure freedom from other seizure types but with no statistical significance: 7% FOS-free, 28% AA-free, 6% Ats-free, and 18% MS-free. Regarding changes of group at 12 months, 22% of TS and 19% of FOS improved significantly to a group with lower seizure frequency (p = 0.004 and p = 0.02, respectively). In remaining groups (4% of GTCS, 11% of AA, 18% of Ats, 18% of MS, and 13% of seizure clusters), the improvement was not statistically significant. Twenty-nine patients discontinued perampanel: 18 (21%) due to AEs, 8 (9%) due to lack of efficacy, and 3 (3%) due to seizure worsening. Adverse events, mostly mild or moderate, were reported in 53% of patients, and irritability/mood changes (22%) and somnolence (17%) were the most frequent.

CONCLUSION

This is the first large-scale real-world study with perampanel across different seizure types in patients with DEEs. Perampanel was effective, especially in GTCS, TS, and FOS, as well as in seizure clusters. Perampanel was generally well-tolerated without unexpected AEs.

Treatment strategies for Lennox-Gastaut syndrome: outcomes of multimodal treatment approaches

Background

Multimodal treatment approaches are often considered for patients with Lennox-Gastaut syndrome (LGS). Creating an algorithm that can guide healthcare providers in selecting treatment options for patients with LGS remains a challenge. Herein, we assessed the long-term seizure-free and neurodevelopmental outcomes of stepwise multimodal treatment in patients with LGS.

Objective

Herein, we assess the long-term seizure-free and neurodevelopmental outcomes of stepwise multimodal treatment in patients with LGS.

Methods

We retrospectively examined the data of 371 patients with LGS who underwent stepwise multimodal treatment, including antiseizure medication (ASM) therapy, dietary therapy (DT), resective epilepsy surgery (R-ES), and palliative epilepsy surgery (P-ES). The seizure-free outcome was considered to be the effect of the final treatment according to the treatment algorithm, and the percentage of patients who remained seizure-free in each treatment group was calculated. ASM treatment, DT, R-ES, and P-ES were applied to 371 (100%), 201 (54.2%), 112 (30.2%), and 115 (31.0%) patients with LGS, respectively. We evaluated the stepwise multimodal treatment outcomes in these patients.

Results

One hundred sixty-eight patients (45.3%) remained seizure-free for at least 1 year (seizure-free-for-1-year group), 61 of whom (16.5%) remained seizure-free for more than 5 years (remained-seizure-free group). Among the patients treated with ASM therapy, DT, R-ES, and P-ES, 41 (11.1%), 53 (14.3%), 56 (15.1%), and 29 (7.8%), respectively, remained seizure-free for 1 year. In addition, 15 (4.1%), 15 (4.1%), 19 (5.1%), and 12 (3.2%) patients in the ASM, DT, R-ES, and P-ES treatment groups, respectively, remained seizure-free for more than 5 years. Both the seizure-free-for-1-year and remained-seizure-free groups showed significant improvement in electroencephalography findings and neurodevelopmental status following treatment.

Conclusion

This study provides an update on the long-term seizure outcomes and neurodevelopmental improvements in a large cohort of patients with LGS following comprehensive multimodal treatment. We emphasize that the active combination of multiple ASMs, DT, and surgical treatment could provide long-term seizure-free outcomes and significant neurological benefits to patients with LGS.

International League Against Epilepsy classification and definition of epilepsy syndromes with onset in childhood: Position paper by the ILAE Task Force on Nosology and Definitions

The 2017 International League Against Epilepsy classification has defined a three-tier system with epilepsy syndrome identification at the third level. Although a syndrome cannot be determined in all children with epilepsy, identification of a specific syndrome provides guidance on management and prognosis. In this paper, we describe the childhood onset epilepsy syndromes, most of which have both mandatory seizure type(s) and interictal electroencephalographic (EEG) features. Based on the 2017 Classification of Seizures and Epilepsies, some syndrome names have been updated using terms directly describing the seizure semiology. Epilepsy syndromes beginning in childhood have been divided into three categories: (1) self-limited focal epilepsies, comprising four syndromes: self-limited epilepsy with centrotemporal spikes, self-limited epilepsy with autonomic seizures, childhood occipital visual epilepsy, and photosensitive occipital lobe epilepsy; (2) generalized epilepsies, comprising three syndromes: childhood absence epilepsy, epilepsy with myoclonic absence, and epilepsy with eyelid myoclonia; and (3) developmental and/or epileptic encephalopathies, comprising five syndromes: epilepsy with myoclonic-atonic seizures, Lennox-Gastaut syndrome, developmental and/or epileptic encephalopathy with spike-and-wave activation in sleep, hemiconvulsion-hemiplegia-epilepsy syndrome, and febrile infection-related epilepsy syndrome. We define each, highlighting the mandatory seizure(s), EEG features, phenotypic variations, and findings from key investigations.

New and emerging pharmacologic treatments for developmental and epileptic encephalopathies

PURPOSE OF REVIEW

Summarize evidence on Developmental and Epileptic Encephalopathies (DEEs) treatments focusing on new and emerging pharmacologic therapies (see Video, http://links.lww.com/CONR/A61, Supplementary Digital Content 1, which provides an overview of the review).

RECENT FINDINGS

Advances in the fields of molecular genetics and neurobiology have led to the recognition of underlying pathophysiologic mechanisms involved in an increasing number of DEEs that could be targeted with precision therapies or repurposed drugs, some of which are currently being evaluated in clinical trials. Prompt, optimal therapy is critical, and promising therapies approved or in clinical trials for tuberous sclerosis complex, Dravet and Lennox-Gastaut Syndromes including mammalian target of rapamycin inhibitors, selective membrane channel and antisense oligonucleotide modulation, and repurposed drugs such as fenfluramine, stiripentol and cannabidiol, among others, may improve seizure burden and neurological outcomes. There is an urgent need for collaborative efforts to evaluate the efficacy and safety of emerging DEEs therapies.

SUMMARY

Development of new therapies promise to address unmet needs for patients with DEEs, including improvement of neurocognitive function and quality of life.

Neurophysiological Findings in Neuronal Ceroid Lipofuscinoses

Neuronal ceroid lipofuscinoses (NCLs) are a heterogeneous group of neurodegenerative diseases, characterized by progressive cerebral atrophy due to lysosomal storage disorder. Common clinical features include epileptic seizures, progressive cognitive and motor decline, and visual failure, which occur over different time courses according to subtypes. During the latest years, many advances have been done in the field of targeted treatments, and in the next future, gene therapies and enzyme replacement treatments may be available for several NCL variants. Considering that there is rapid disease progression in NCLs, an early diagnosis is crucial, and neurophysiological features might have a key role for this purpose. Across the different subtypes of NCLs, electroencephalogram (EEG) is characterized by a progressive deterioration of cerebral activity with slowing of background activity and disappearance of spindles during sleep. Some types of heterogeneous abnormalities, diffuse or focal, prevalent over temporal and occipital regions, are described in many NCL variants. Photoparoxysmal response to low-frequency intermittent photic stimulation (IPS) is a typical EEG finding, mostly described in CLN2, CLN5, and CLN6 diseases. Visual evoked potentials (VEPs) allow to monitor the visual functions, and the lack of response at electroretinogram (ERG) reflects retinal neurodegeneration. Taken together, EEG, VEPs, and ERG may represent essential tools toward an early diagnosis of NCLs.

Epilepsy Surgery: Special Circumstances

Epilepsy surgery has proven to be very effective in treating refractory focal epilepsies in children, producing seizure freedom or partial seizure control well beyond any other medical or dietary therapies. While surgery is mostly utilized in certain clinical phenotypes, either based on the location such as temporal lobe epilepsy, or based on the presence of known epileptogenic lesions such as focal cortical dysplasia, tumors or hemimegalencephaly, there is a growing body of evidence to support the role of surgery in other patients' cohorts that were classically not thought of as surgical candidates. These include patients with rare genetic disorders, electrical status epilepticus in sleep, status epilepticus and the very young patients. Furthermore, epilepsy surgery is not considered as a "last resort" as seizure and cognitive outcomes of surgery are considerably better when done earlier rather than later in relation to the time of onset of epilepsy and age of surgery especially in the context of known focal cortical dysplasia. This article examines the accumulating evidence of the utility of epilepsy surgery in these special circumstances.

Complications and Sequelae in Patients With Congenital Microcephaly Associated With Zika Virus Infection: Two-Year Follow-Up

BACKGROUND

We aim to describe the long term follow-up of a cohort of children exposed in utero to the Zika virus.

METHODS

Descriptive study of a cohort of microcephalic children due to Zika virus. Logistic regression was used to evaluate variables associated with worse prognosis epilepsy.

RESULTS

We followed 28 children (15 females), with a median follow-up of 24 months (IQR = 12-28). During the follow-up, 1 infant died. The median head circumference at birth was 29 cm (IQR = 27-31). All presented a global developmental delay. The most frequent central nervous system abnormalities were on cortical development in 22 participants; dysgenesis of corpus callosum in 13; ventriculomegaly in 25; and calcifications in 24. A total of 9 presented ocular abnormalities, 4 auditory impairment. During follow-up, 12 presented with sleep disorders, 10 with irritability, and 23 with epilepsy (2 with generalized tonic-clonic, 3 with generalized tonic-clonic and spasms, 12 with spasms, 3 tonic and spasms, and 3 motor focal and spasms). The median age at the begin of the epilepsy was 4 months (IQR = 2-10), the median number of drugs used to control the epilepsy was 2 (IQR = 2-3). Maternal illicit drug use during pregnancy was associated with worse prognosis epilepsy (Lennox-Gastaut syndrome, West syndrome, or status epilepticus). A total of 19 presented with dysphagia, 10 children required gastrostomy.

CONCLUSION

Children with microcephaly due to Zika virus presented with several complications during follow-up, as epilepsy, spastic diplegia, and global developmental delay.

Time to onset of cannabidiol (CBD) treatment effect in Lennox-Gastaut syndrome: Analysis from two randomized controlled trials

OBJECTIVE

To estimate time to onset of cannabidiol (CBD) treatment effect (seizure reduction and adverse events [AEs]), we conducted post hoc analyses of data from two randomized, placebo-controlled, Phase 3 trials, GWPCARE3 (NCT02224560) and GWPCARE4 (NCT02224690), of patients with Lennox-Gastaut syndrome.

METHODS

Patients received plant-derived pharmaceutical formulation of highly purified CBD (Epidiolex, 100 mg/ml oral solution) at 10 mg/kg/day (CBD10; GWPCARE3) or 20 mg/kg/day (CBD20; both trials) or placebo for 14 weeks. Treatment started at 2.5 mg/kg/day for all groups and reached 10 mg/kg/day on Day 7 and 20 mg/kg/day (CBD20 and matching placebo only) on Day 11. Percentage change from baseline in drop seizure frequency was calculated by cumulative day (i.e., including all previous days). Time to onset and resolution of AEs were evaluated.

RESULTS

Overall, 235 patients received CBD (CBD10 [GWPCARE3 only], n = 67; CBD20 [pooled GWPCARE3&4], n = 168) and 161 received placebo. Mean (range) age was 15.3 years (2.6-48.0). Patients had previously discontinued a median (range) of six (0-28) antiepileptic drugs (AEDs) and were currently taking a median of three (0-5) AEDs. Differences in drop seizure reduction between placebo and CBD emerged during the titration period and became nominally significant by Day 6 (p = .008) for pooled CBD treatment groups. Separation between placebo and CBD in ≥50% responder rate emerged by Day 6. Onset of the first reported AE occurred during the titration period in 45% of patients (CBD10, 46%; CBD20, 52%; placebo, 38%). In patients with AEs, resolution occurred within 4 weeks of onset in 53% of placebo and 39% of CBD patients and by end of study in 63% of placebo and 61% of CBD patients.

SIGNIFICANCE

Treatment effect (efficacy and AEs) of CBD may occur within 1 week of starting treatment. Although AEs lasted longer for CBD than placebo, most resolved within the 14-week period.

Anti-seizure medications for Lennox-Gastaut syndrome

BACKGROUND

Lennox-Gastaut syndrome (LGS) is an age-specific epilepsy syndrome characterised by multiple seizure types, including drop seizures. LGS has a characteristic electroencephalogram, an onset before age eight years and an association with drug resistance. This is an updated version of the Cochrane Review published in 2013.

OBJECTIVES

To assess the efficacy and tolerability of anti-seizure medications (ASMs) for LGS.

SEARCH METHODS

We searched the Cochrane Register of Studies (CRS Web) and MEDLINE (Ovid, 1946 to 28 February 2020) on 2 March 2020. CRS Web includes randomised controlled trials (RCTs) or quasi-RCTs from the Cochrane Central Register of Controlled Trials (CENTRAL); the Specialised Registers of Cochrane Review Groups, including Cochrane Epilepsy; PubMed; Embase; ClinicalTrials.gov; and the World Health Organization's International Clinical Trials Registry Platform (ICTRP). We imposed no language restrictions. We contacted pharmaceutical companies and colleagues in the field to seek any unpublished or ongoing studies.

SELECTION CRITERIA

We considered RCTs, including cross-over trials, of ASMs for LGS in children and adults. We included studies of ASMs used as either monotherapy or as an add-on (adjunctive) therapy. We excluded studies comparing different doses of the same ASM.

DATA COLLECTION AND ANALYSIS

We used standard Cochrane methodological procedures, including independent, dual assessment for risk of bias and application of the GRADE approach to rate the evidence certainty for outcomes.

MAIN RESULTS

We found no trials of ASM monotherapy. The review included 11 trials (1277 participants; approximately 11 weeks to 112 weeks follow-up after randomisation) using add-on ASMs for LGS in children, adolescents and adults. Two studies compared add-on cannabidiol (two doses) with add-on placebo in children and adolescents only. Neither study reported overall seizure cessation or reduction. We found high-certainty evidence that 72 more people per 1000 (confidence interval (CI) 4 more to 351 more) had adverse events (AE) leading to study discontinuation with add-on cannabidiol, compared to add-on placebo (two studies; 396 participants; risk ratio (RR) 4.90, 95% CI 1.21 to 19.87). One study compared add-on cinromide with add-on placebo in children and adolescents only. We found very low-certainty evidence that 35 more people per 1000 (CI 123 fewer to 434 more) had 50% or greater average reduction of overall seizures with add-on cinromide compared to add-on placebo (one study; 56 participants; RR 1.15, 95% CI 0.47 to 2.86). This study did not report participants with AE leading to study discontinuation. One study compared add-on clobazam (three doses) with add-on placebo. This study did not report overall seizure cessation or reduction. We found high-certainty evidence that 106 more people per 1000 (CI 0 more to 538 more) had AE leading to study discontinuation with add-on clobazam compared to add-on placebo (one study; 238 participants; RR 4.12, 95% CI 1.01 to 16.87). One study compared add-on felbamate with add-on placebo. No cases of seizure cessation occurred in either regimen during the treatment phase (one study; 73 participants; low-certainty evidence). There was low-certainty evidence that 53 more people per 1000 (CI 19 fewer to 716 more) with add-on felbamate were seizure-free during an EEG recording at the end of the treatment phase, compared to add-on placebo (RR 2.92, 95% CI 0.32 to 26.77). The study did not report overall seizure reduction. We found low-certainty evidence that one fewer person per 1000 (CI 26 fewer to 388 more) with add-on felbamate had AE leading to study discontinuation compared to add-on placebo (one study, 73 participants; RR 0.97, 95% CI 0.06 to 14.97). Two studies compared add-on lamotrigine with add-on placebo. Neither study reported overall seizure cessation. We found high-certainty evidence that 176 more people per 1000 (CI 30 more to 434 more) had ≥ 50% average seizure reduction with add-on lamotrigine compared to add-on placebo (one study; 167 participants; RR 2.12, 95% CI 1.19 to 3.76). We found low-certainty evidence that 40 fewer people per 1000 (CI 68 fewer to 64 more) had AE leading to study-discontinuation with add-on lamotrigine compared to add-on placebo (one study; 169 participants; RR 0.49, 95% CI 0.13 to 1.82). Two studies compared add-on rufinamide with add-on placebo. Neither study reported seizure cessation. We found high-certainty evidence that 202 more people per 1000 (CI 34 to 567 more) had ≥ 50% average seizure reduction (one study; 138 participants; RR 2.84, 95% CI 1.31 to 6.18). We found low-certainty evidence that 105 more people per 1000 (CI 17 fewer to 967 more) had AE leading to study discontinuation with add-on rufinamide compared to add-on placebo (one study; 59 participants; RR 4.14, 95% CI 0.49 to 34.86). One study compared add-on rufinamide with another add-on ASM. This study did not report overall seizure cessation or reduction. We found low-certainty evidence that three fewer people per 1000 (CI 75 fewer to 715 more) had AE leading to study discontinuation with add-on rufinamide compared to another add-on ASM (one study; 37 participants; RR 0.96, 95% CI 0.10 to 9.57). One study compared add-on topiramate with add-on placebo. This study did not report overall seizure cessation. We found low-certainty evidence for ≥ 75% average seizure reduction with add-on topiramate (one study; 98 participants; Peto odds ratio (Peto OR) 8.22, 99% CI 0.60 to 112.62) and little or no difference to AE leading to study discontinuation compared to add-on placebo; no participants experienced AE leading to study discontinuation (one study; 98 participants; low-certainty evidence).

AUTHORS' CONCLUSIONS

RCTs of monotherapy and head-to-head comparison of add-on ASMs are currently lacking. However, we found high-certainty evidence for overall seizure reduction with add-on lamotrigine and rufinamide, with low-certainty evidence for AE leading to study discontinuation compared with add-on placebo or another add-on ASM. The evidence for other add-on ASMs for overall seizure cessation or reduction was low to very low with high- to low-certainty evidence for AE leading to study discontinuation. Future research should consider outcome reporting of overall seizure reduction (applying automated seizure detection devices), impact on development, cognition and behaviour; future research should also investigate age-specific efficacy of ASMs and target underlying aetiologies.

The role of surgery in the management of Lennox-Gastaut syndrome: A systematic review and meta-analysis of the clinical evidence

Lennox-Gastaut syndrome (LGS) is a severe form of childhood onset epilepsy in which patients require multiple medications and may be candidates for palliative surgical intervention. In this meta-analysis, we sought to evaluate the impact of palliative vagus nerve stimulation (VNS), corpus callosotomy (CC), and resective surgery (RS) by analyzing their impact on seizure control, antiepileptic drug (AED) usage, quality of life (QOL), behavior, cognition, prognostic factors, and complications. A systematic search of PubMed MEDLINE, Scopus, and Cochrane Database of Systematic Reviews was performed to find articles that met the following criteria: (1) prospective/retrospective study with original data, (2) at least one LGS surgery patient aged less than 18 years, and (3) information on seizure frequency reduction (measured as percentage, Engel class, or qualitative comment). Seizures were analyzed quantitatively in a meta-analysis of proportions and a random-effects model, whereas other outcomes were analyzed qualitatively. Forty studies with 892 LGS patients met the selection criteria, with 19 reporting on CC, 17 on VNS, four on RS, two on RS + CC, one on CC + VNS, and one on deep brain stimulation. CC seizure reduction rate was 74.1% (95% confidence interval [CI] = 64.5%-83.7%), and VNS was 54.6% (95% CI = 42.9%-66.3%), which was significantly different (p < .001). RS seizure reduction was 88.9% (95% CI = 66.1%-99.7%). Many VNS patients reported alertness improvements, and most had no major complications. VNS was most effective for atonic/tonic seizures; higher stimulation settings correlated with better outcomes. CC patients reported moderate cognitive and QOL improvements; disconnection syndrome, transient weakness, and respiratory complications were noted. Greater callosotomy extent correlated with better outcomes. AED usage most often did not change after surgery. RS showed considerable QOL improvements for patients with localized seizure foci. In the reported literature, CC appeared to be more effective than VNS for seizure reduction. VNS may provide a similar or higher level of QOL improvement with lower aggregate risk of complications. Patient selection, anatomy, and seizure type will inform decision-making.

Risk factors, etiologies, and comorbidities in urban pediatric epilepsy

The Seizures and Outcomes Study in Children (SOS-KIDS) identifies risk factors, etiologies, and comorbidities in a pediatric epilepsy population in a major city with diversity in socioeconomic levels. A thorough understanding of the range of issues impacting children with epilepsy is critical to establishing treatment that will produce better health outcomes. SOS-KIDS is a cross-sectional cohort study of pediatric epilepsy patients who live in Washington D.C. and are evaluated at Children's National Hospital. Families were recruited at the time of the child's routine clinic appointment or inpatient visit. Information was extracted from participants' electronic medical records (EMR) and parent reports; participants were screened for comorbidities using standardized screening measures. Data were collected from 289 participants (47% female, 53% male), and mean age was 7.9 years (2 months to 17 years). Twenty-nine percent of participants had primary generalized epilepsy, 63% focal epilepsy, 0.3% combined generalized and focal epilepsy, and 8% could not be distinguished. There were a variety of epilepsy risk factors including prematurity (10%), intraventricular hemorrhage (7%), neonatal seizures (8%), and febrile seizures (17%). The most common etiologies were cerebral malformations (13%) and genetic disorders (25%). Numerous participants had documented comorbidities including developmental delay (56%), intellectual disability (20%), headaches (16%), attention-deficit hyperactivity disorder (23%), and autism (7%). Of participants aged six years and older, depression, and anxiety were reported in 5% and 6% within the EMR, 14% and 19% in parent surveys, and 22% and 33% with standardized screening measures. We identified a wide variety of risk factors and etiologies among urban pediatric epilepsy patients, with genetic and structural being the most common. Neurologic and psychiatric comorbidities were common, but the prevalence of several psychiatric disorders reported within the EMR was substantially lower compared to that found when using parent surveys and standardized screening measures.

Cost-Effectiveness of Cannabidiol Adjunct Therapy versus Usual Care for the Treatment of Seizures in Lennox-Gastaut Syndrome

BACKGROUND

Cannabidiol (CBD) is a novel therapy for the treatment of Lennox-Gastaut Syndrome (LGS), a rare, treatment-refractory epileptic encephalopathy. Two pivotal trials found CBD 20 mg/kg/day conferred a reduction from baseline in median drop seizure frequency of 44% and 42%, respectively, compared with 22% and 17%, respectively, in the usual care arms. No economic evaluations have been published to date. This analysis assessed the cost effectiveness of CBD adjunct therapy compared with usual care alone in LGS from the US payer perspective.

METHODS

We developed a lifetime horizon Markov decision analytic model. Efficacy, healthcare costs (2020 US$), and health state utilities were ascertained from published clinical trials, retrospective analyses, and time trade-off interviews conducted in the UK, respectively. Fifteen-year-old patients entering the model transitioned to states representing a percentage reduction in drop seizure frequency from baseline, where they remained until reverting back to baseline drop seizure frequency, or death. One-way and probabilistic sensitivity analyses were conducted to evaluate parameter uncertainty, and scenario analyses investigated the impact of various assumptions. Costs and outcomes were discounted at 3%.

RESULTS

Compared with usual care alone, CBD yielded 0.7 additional quality-adjusted life-years (QALYs) and $314,900 additional healthcare expenditure, resulting in $451,800 per QALY. Uncertainty in health state utilities were the largest contributor to uncertainty in the results. Results from the 5000-simulation probabilistic sensitivity analysis indicated a 0% chance of CBD being cost effective at a $150,000 per QALY willingness-to-pay threshold, with a 95% credible range for the incremental cost-effectiveness ratio of $325,300-$690,000 per QALY.

CONCLUSION

CBD does not appear to be a cost-effective therapeutic option in LGS patients at a willingness-to-pay threshold of $150,000/QALY.

The Biochemical Profile of Post-Mortem Brain from People Who Suffered from Epilepsy Reveals Novel Insights into the Etiopathogenesis of the Disease

Epilepsy not-otherwise-specified (ENOS) is one of the most common causes of chronic disorders impacting human health, with complex multifactorial etiology and clinical presentation. Understanding the metabolic processes associated with the disorder may aid in the discovery of preventive and therapeutic measures. Post-mortem brain samples were harvested from the frontal cortex (BA8/46) of people diagnosed with ENOS cases (n = 15) and age- and sex-matched control subjects (n = 15). We employed a targeted metabolomics approach using a combination of proton nuclear magnetic resonance (¹H-NMR) and direct injection/liquid chromatography tandem mass spectrometry (DI/LC-MS/MS). We accurately identified and quantified 72 metabolites using ¹H-NMR and 159 using DI/LC-MS/MS. Among the 212 detected metabolites, 14 showed significant concentration changes between ENOS cases and controls (p < 0.05; q < 0.05). Of these, adenosine monophosphate and O-acetylcholine were the most commonly selected metabolites used to develop predictive models capable of discriminating between ENOS and unaffected controls. Metabolomic set enrichment analysis identified ethanol degradation, butyrate metabolism and the mitochondrial beta-oxidation of fatty acids as the top three significantly perturbed metabolic pathways. We report, for the first time, the metabolomic profiling of postmortem brain tissue form patients who died from epilepsy. These findings can potentially expand upon the complex etiopathogenesis and help identify key predictive biomarkers of ENOS.

An overview of health issues and development in a large clinical cohort of children with Angelman syndrome

This study presents a broad overview of health issues and psychomotor development of 100 children with Angelman syndrome (AS), seen at the ENCORE Expertise Center for AS in Rotterdam, the Netherlands. We aimed to further delineate the phenotype of AS, to evaluate the association of the phenotype with genotype and other determinants such as epilepsy and to get insight in possible targets for intervention. We confirmed the presence of a more severe phenotype in the 15q11.2‐q13 deletion subtype. Novel findings were an association of (early onset of) epilepsy with a negative effect on development, a high occurrence of nonconvulsive status epilepticus, a high rate of crouch gait in the older children with risk of deterioration of mobility, a relatively low occurrence of microcephaly, a higher mean weight for height in all genetic subtypes with a significant higher mean in the nondeletion children, and a high occurrence of hyperphagia across all genetic subtypes. Natural history data are needed to design future trials. With this large clinical cohort with structured prospective and multidisciplinary follow‐up, we provide unbiased data on AS to support further intervention studies to optimize outcome and quality of life of children with AS and their family.

Immediate outcomes in early life epilepsy: A contemporary account

RATIONALE

Early-life epilepsies (ELEs) include some of the most challenging forms of epilepsy to manage. Given recent diagnostic and therapeutic advances, a contemporary assessment of the immediate short-term outcomes can provide a valuable framework for identifying priorities and benchmarks for evaluating quality improvement efforts.

METHODS

Children with newly diagnosed epilepsy and onset <3 years were prospectively recruited through 17 US hospitals, from 2012 to 2015 and followed for 1 year after diagnosis. Short-term outcome included mortality, drug resistance, evolution of nonsyndromic epilepsy to infantile spasms (IS) and from IS to other epilepsies, and developmental decline. Multivariable analyses assessed the risk of each outcome.

RESULTS

Seven hundred seventy-five children were recruited, including 408 (53%) boys. Median age at onset was 7.5 months (interquartile range (IQR): 4.2-16.5), and 509 (66%) had onset in the first year of life. Of 22 deaths that occurred within one year of epilepsy diagnosis, 21 were children with epilepsy onset in infancy (<12 months). Of 680 children followed ≥6 months, 239 (35%) developed drug-resistant seizures; 34/227 (15%) infants with nonsyndromic epilepsy developed IS, and 48/210 (23%) initially presenting with IS developed additional seizure types. One hundred of 435 (23%) with initially typical development or only mild/equivocal delays at seizure onset, had clear developmental impairment within one year after initial diagnosis. Each outcome had a different set of predictors; however, younger age and impaired development at seizure onset were broadly indicative of poorer outcomes. Type of epilepsy and early identification of underlying cause were not reliable predictors of these outcomes.

CONCLUSION

Early-life epilepsies carry a high risk of poor outcome which is evident shortly after epilepsy diagnosis. Onset in infancy and developmental delay is associated with an especially high risk, regardless of epilepsy type. The likelihood of poor outcomes is worrisome regardless of specific clinical profiles.