Search

Objective Methods Results Significance The cannabinoid cannabidiol has established antiseizure effects in drug‐resistant epilepsies such as Dravet syndrome and Lennox–Gastaut syndrome. Amorfrutin 2, honokiol, and magnolol are structurally similar to cannabinoids (cannabis‐like drugs) but derive from non‐cannabis plants. We aimed to study the antiseizure potential of these compounds in various mouse seizure models. In addition, we aimed to characterize their molecular pharmacology at cannabinoid CB1 and CB2 receptors and at T‐type calcium channels, which are known targets of the cannabinoids.Brain and plasma pharmacokinetic profiles were determined. Antiseizure activity was assessed against hyperthermia‐induced seizures in a Scn1a+/− mouse model of Dravet syndrome. We then elaborated on the most promising compounds in the maximal electroshock (MES) test in mice and the Gabrb3+/D120N mouse model of Lennox–Gastaut syndrome. Fluorescence‐based assays were used to examine modulatory activity at cannabinoid CB1 and CB2 receptors and T‐type calcium channel subtypes CaV3.1, CaV3.2, and CaV3.3 overexpressed in mammalian cells. Automated patch‐clamp electrophysiology was then used to confirm inhibitory activity on CaV3.1, CaV3.2, and CaV3.3 channels.Magnolol and honokiol had high brain‐to‐plasma ratios (3.55 and 7.56, respectively), unlike amorfrutin 2 (0.06). Amorfrutin 2 and magnolol but not honokiol significantly increased the body temperature threshold at which Scn1a+/− mice had a generalized tonic–clonic seizure. Both amorfrutin 2 and magnolol significantly decreased the proportion of mice exhibiting hindlimb extension in the MES test. Furthermore, magnolol reduced the number and duration of atypical absence seizures in Gabrb3+/D120N mice. The three compounds inhibited all T‐type calcium channel subtypes but were without specific activity at cannabinoid receptors.We show for the first time that amorfrutin 2 and magnolol display novel antiseizure activity in mouse drug‐resistant epilepsy models. Our results justify future drug discovery campaigns around these structural scaffolds that aim to develop novel antiseizure drugs for intractable epilepsies. [ABSTRACT FROM AUTHOR]

NUS1 encodes the Nogo-B receptor, a critical regulator for unfolded protein reaction (UPR) signaling. Although several loss-of-function variants of NUS1 have been identified in patients with developmental and epileptic encephalopathy (DEE), the role of the NUS1 variant in Lennox-Gastaut syndrome (LGS), a severe child-onset DEE, remains unknown. In this study, we identified two de novo variants of NUS1, a missense variant (c.868 C > T/p.R290C) and a splice site variant (c.792-2 A > G), in two unrelated LGS patients using trio-based whole-exome sequencing performed in a cohort of 165 LGS patients. Both variants were absent in the gnomAD population and showed a significantly higher observed number of variants than expected genome-wide. The R290C variant was predicted to damage NUS1 and decrease its protein stability. The c.792-2 A > G variant caused premature termination of the protein. Knockdown of NUS1 activated the UPR pathway, resulting in apoptosis of HEK293T cells. Supplementing cells with expression of wild-type NUS1, but not the mutant (R290C), rescued UPR activation and apoptosis in NUS1 knockdown cells. Compared to wild-type Drosophila, seizure-like behaviors and excitability in projection neurons were significantly increased in Tango14 (homolog of human NUS1) knockdown and Tango14R290C/+ knock-in Drosophila. Additionally, abnormal development and a small body size were observed in both mutants. Activated UPR signaling was also detected in both mutants. Thus, NUS1 is a causative gene for LGS with dominant inheritance. The pathogenicity of these variants is related to the UPR signaling activation, which may be a common pathogenic mechanism of DEE. [ABSTRACT FROM AUTHOR]

The article delves into the significance of recognizing variations among direct-acting oral anticoagulants (DOACs) when treating patients with epilepsy, particularly in relation to concomitant antiseizure medications (ASMs). It suggests that edoxaban may be the preferred DOAC for patients with epilepsy, especially when paired with mild to moderate CYP3A-inducing ASMs. The study also cautions about potential interactions with CYP3A4/P-gp inhibiting ASMs, advising careful monitoring, especially with cannabidiol. Additionally, the article explores the association between non-vitamin K oral anticoagulants and the risk of major bleeding in patients with nonvalvular atrial fibrillation, emphasizing the importance of assessing drug interactions for effective and safe treatment. [Extracted from the article]

The article discusses a case report of a 36-year-old male with drug-resistant post-traumatic epilepsy who achieved seizure freedom without medication after stereoelectroencephalography (sEEG) implantation. The patient underwent sEEG monitoring, which captured a single event without sEEG correlate, prompting further investigation. Despite discontinuing all seizure medications, the patient remained seizure-free for over 3.5 years. The article highlights the potential benefits and risks of sEEG procedures in drug-resistant epilepsy cases, emphasizing the need for further research into potential tissue injury caused by depth electrode insertion. [Extracted from the article]

Why you should read this article: • To develop your knowledge of rare epilepsy syndromes • To enhance your understanding of the association between epilepsy and learning disability • To contribute towards revalidation as part of your 35 hours of CPD (UK readers) • To contribute towards your professional development and local registration renewal requirements (non-UK readers). Epilepsy is more prevalent in people with learning disabilities than in the general population and there are a number of rare epilepsy syndromes closely associated with learning disability. These syndromes are challenging to manage, notably because seizures are often refractory, the risk of status epilepticus is high and comorbidities are usually present. People with a rare epilepsy syndrome need high levels of specialist support throughout their lives. Such syndromes are rare, but professionals who care for people with learning disabilities are likely to encounter them at some point in their career. Improved knowledge and understanding of rare epilepsy syndromes can assist learning disability nurses to provide adequate information, care and support to service users, family members and paid carers as well as to other healthcare professionals. This article explains the association between epilepsy and learning disability, describes rare epilepsy syndromes and explores the goals of treatment, additional treatment options and challenges of management. [ABSTRACT FROM AUTHOR]

Objectives The present study was designed to study the efficacy of sequential dietary therapy with a modified Atkins diet (mAD) followed by low glycemic index treatment (LGIT) in treating drug-resistant epilepsy in children. Methods This interventional study was conducted from February 2021 to February 2022 among children aged 6 months to 5 years who had failed to respond to more than two conventional and correctly chosen antiseizure medications. The primary endpoint was the proportion of good responders, that is, children with more than 50% seizure reduction. Secondary outcome measures were the proportion of children with seizure freedom, > 90% seizure reduction, and the nature of parent-reported adverse events. Results A total of 45 children were recruited for the study, with 6 children being lost to follow-up at 12 weeks. At 12 weeks, 30 of 39 (76.9%) children were good responders with more than 50% seizure reduction. Of these 30 children, 11 (24.4%) had more than 90% seizure reduction, with 9 (20%) achieving complete spasm freedom. Constipation was the most common side effect of the diet among the enrolled subjects. Conclusion Clinicians can consider sequential dietary therapy with a mAD in the first month followed by LGIT in the next 2 months for treating children who could not tolerate mAD beyond 1 month. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Background: Drug-resistant epilepsy (DRE) impacts a significant portion, onethird, of individuals diagnosed with epilepsy. In such cases, exploring nonpharmacological interventions are crucial, with the ketogenic diet (KD) standing out as a valuable option. KD, a high-fat and low-carb dietary approach with roots dating back to the 1920s for managing DRE, triggers the formation of ketone bodies and modifies biochemistry to aid in seizure control. Recent studies have increasingly supported the efficacy of KD in addressing DRE, showcasing positive outcomes. Furthermore, while more research is needed, limited data suggests that KD May also be beneficial for specific genetic epilepsy syndromes (GESs). Objective: This study aimed to assess the short-term efficacy of KD among pediatric patients diagnosed with GESs. Materials and methods: This is a multi-center retrospective analysis of pediatric patients with GESs diagnosed using next-generation sequencing. The enrolled patients followed the keto-clinic protocol, and the KD efficacy was evaluated at 3, 6, and 12-month intervals based on seizure control and compliance. The collection instrument included demographic, baseline, and prognostic data. The collected data was coded and analyzed promptly. Results: We enrolled a cohort of 77 patients with a mean current age of 7.94 ± 3.83 years. The mean age of seizure onset was 15.5 months. Notably, patients experienced seizures at a younger age tended to have less positive response to diet. Overall, 55 patients responded favorably to the diet (71.4%) while 22 patients (28.6%) showed no improvement. Patients with genetic etiology showed a significantly more favorable responses to the dietary intervention. Patients with Lennox-Gastaut syndrome showed the most significant improvement (14/15) followed by patients with Dravet syndrome (6/8), and West syndrome (3/4). The number of used anti-seizure medications also played a significant role in determining their response to the diet. While some patients experienced mild adverse events, the most common being constipation, these occurrences were not serious enough to necessitate discontinuation of the diet. Conclusion: The study revealed a high improvement rate in seizure control, especially among younger patients and those with later seizure onset. The success of dietary treatment hinges greatly on early intervention and the patient's age. Certain genetic mutations responded favorably to the KD, while efficacy varied among various genetic profiles. [ABSTRACT FROM AUTHOR]

Objective: Historically, epilepsy has been the most frequently presenting feature of tuberous sclerosis complex (TSC). Advances in TSC health care have occurred over the past decade; thus, we studied whether TSC epilepsy outcomes have changed. Method: A retrospective chart review was undertaken for all children with TSC in Queensland, Australia. Epilepsy outcome and TSC diagnosis data were extracted, and data were compared between children born before 2012 with those born in or after 2012. Results: In this retrospective cohort, TSC diagnosis in children born in or after 2012 is now predominantly antenatal (51%, p <.05). Most patients with epilepsy are now known to have TSC before they develop epilepsy. Despite earlier TSC diagnosis, the frequency of epilepsy (85%) has not changed (p =.92), but diagnosis trends toward an earlier age (median = 3 months for patients born in or after 2012 vs. 5.5 months for those born before 2012, p =.23). Most (95%) patients had focal seizures as their initial clinical seizure type; it was rare (5%) for epileptic spasms (ES) to be the initial seizure type. The frequency of ES was lower in patients born in or after 2012 (36% vs. 50%, p =.27). Infantile (<24 months) onset ES was not associated with worse epilepsy outcome. Late onset ES was seen in 14%, and these patients had a lower rate of epilepsy remission. Lennox–Gastaut syndrome was seen in 7%. Febrile/illness‐related status epilepticus occurred in 12% of patients, between 1 and 4 years of age. Despite many (78%) patients having multiple daily seizures at maximal seizure frequency, and 74% meeting criteria for treatment‐refractory epilepsy, most patients achieved epilepsy remission (66%), either with epilepsy surgery (47%) or with age (53%). At the time of inclusion in this study, only 21% of patients had uncontrolled frequent (daily to 3 monthly) seizures and 14% had uncontrolled infrequent (3 monthly to <2 yearly) seizures. Significance: This study provides updated information that informs the counseling of parents of newly diagnosed pediatric TSC patients. [ABSTRACT FROM AUTHOR]

Neurodevelopmental disorder with dysmorphic facies and distal limb anomalies (NEDDFL) is associated to BPTF gene haploinsufficiency. Epilepsy was not included in the initial descriptions of NEDDFL, but emerging evidence indicates that epileptic seizures occur in some affected individuals. This study aims to investigate the electroclinical epilepsy features in individuals with NEDDFL. We enrolled individuals with BPTF -related seizures or interictal epileptiform discharges (IEDs) on electroencephalography (EEG). Demographic, clinical, genetic, raw EEG, and neuroimaging data as well as response to antiseizure medication were assessed. We studied 11 individuals with a null variant in BPTF , including five previously unpublished ones. Median age at last observation was 9 years (range: 4 to 43 years). Eight individuals had epilepsy, one had a single unprovoked seizure, and two showed IEDs only. Key features included (1) early childhood epilepsy onset (median 4 years, range: 10 months to 7 years), (2) well-organized EEG background (all cases) and brief bursts of spikes and slow waves (50% of individuals), and (3) developmental delay preceding seizure onset. Spectrum of epilepsy severity varied from drug-resistant epilepsy (27%) to isolated IEDs without seizures (18%). Levetiracetam was widely used and reduced seizure frequency in 67% of the cases. Our study provides the first characterization of BPTF -related epilepsy. Early-childhood-onset epilepsy occurs in 19% of subjects, all presenting with a well-organized EEG background associated with generalized interictal epileptiform abnormalities in half of these cases. Drug resistance is rare. [ABSTRACT FROM AUTHOR]

Copyright of Neurologie Pro Praxi is the property of SOLEN sro and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Objective: This study aimed to investigate the prevalence of autism spectrum disorder and its possible correlations with clinical characteristics in patients with infantile epileptic spasms syndrome in a single center in Brazil. Methods: This retrospective cross-sectional study examined 53 children with the diagnosis of infantile epileptic spasms syndrome prior to an autism spectrum disorder assessment. Participants were divided into two groups based on the presence or absence of autism spectrum disorder. Available variables (sex, medications, median age at onset of infantile epileptic spasms syndrome, and presence of comorbidities) were compared using Mann-Whitney U or chi-square tests. Results: Among the included patients, 12 (23 %) were diagnosed with autism spectrum disorder, corresponding to a relative risk of 0.29 (95 % confidence interval 0.174-0.492). The age at the first seizure ranged from 3 to 15 months, with a mean of 6.65 months. This age significantly differed between participants with autism spectrum disorder (10.58 months) and those without (5.43 months), p<0.001. [ABSTRACT FROM AUTHOR]

Abstract 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.

Abstract Objective To evaluate the Refractory Epilepsy Screening Tool for Lennox–Gastaut Syndrome (REST‐LGS) for real‐world identification of LGS in adults and to develop a scoring system for the tool. Methods A retrospective chart review of adults with drug resistant epilepsy (DRE) and intellectual development disorder (IDD) was conducted by 2 primary care providers blinded to diagnosis. The REST‐LGS was designed via the Modified Delphi Consensus and was previously validated. This tool consists of 8 criteria (4 major, 4 minor) considered indicative of LGS. To account for missing data in the earlier validation study and to evaluate applicability in a real‐world setting, the REST‐LGS was refined to include a scoring system in which major criteria were more heavily weighted than minor criteria, producing categories of “likely” (>11 points), “possible” (8–11 points), and “unlikely” (

To evaluate the utility of genetic testing for etiology-specific diagnosis (ESD) in infantile epileptic spasms syndrome (IESS) with a step-based diagnostic approach in the next-generation sequencing (NGS) era. The study cohort consisted of 314 patients with IESS, followed by the Pediatric Neurology Division of Ege University Hospital between 2005 and 2021. The ESD was evaluated using a step-based approach: step I (clinical phenomenology), step II (neuroimaging), step III (metabolic screening), and step IV (genetic testing). The diagnostic utility of genetic testing was evaluated to compare the early-NGS period (2005 to 2013, n = 183) and the NGS era (2014 to 2021, n = 131). An ESD was established in 221 of 314 (70.4%) infants with IESS: structural, 40.8%; genetic, 17.2%; metabolic, 8.3%; immune-infectious, 4.1%. The diagnostic yield of genetic testing increased from 8.9% to 41.7% in the cohort during the four follow-up periods. The rate of unknown etiology decreased from 34.9% to 22.1% during the follow-up periods. The genetic ESD was established as 27.4% with genetic testing in the NGS era. The genetic testing in the NGS era increased dramatically in subgroups with unknown and structural etiologies. The diagnostic yields of the epilepsy panels increased from 7.6% to 19.2%. However, the diagnostic yield of whole exome sequencing remained at similar levels during the early-NGS period at 54.5% and in the NGS era at 59%. The more genetic ESD (27.4%) was defined for IESS in the NGS era with the implication of precision therapy (37.7%). [ABSTRACT FROM AUTHOR]

Six percent of patients with Leigh syndrome (LS) present with infantile epileptic spasms syndrome (IESS). However, treatment strategies for IESS with LS remain unclear. This retrospective study aimed to evaluate the efficacy and safety of treatment strategies in patients with IESS complicated by LS and Leigh-like syndrome (LLS). We distributed questionnaires to 750 facilities in Japan, and the clinical data of 21 patients from 15 hospitals were collected. The data comprised treatment strategies, including adrenocorticotropic hormone (ACTH) therapy, ketogenic diet (KD) therapy, and antiseizure medications (ASMs); effectiveness of each treatment; and the adverse events. The median age at LS and LLS diagnosis was 7 months (range: 0 to 50), whereas that at the onset of epileptic spasms was 7 (range: 3 to 20). LS was diagnosed in 17 patients and LLS in four patients. Seven, two, five, and seven patients received ACTH + ASMs, ACTH + KD + ASMs, KD + ASMs, and ASMs only, respectively. Four (44%) of nine patients treated with ACTH and one (14%) of seven patients treated with KD achieved electroclinical remission within one month of treatment. No patients treated with only ASMs achieved electroclinical remission. Seven patients (33%) achieved electroclinical remission by the last follow-up. Adverse events were reported in four patients treated with ACTH, none treated with KD therapy, and eight treated with ASMs. ACTH therapy shows the best efficacy and rapid action in patients with IESS complicated by LS and LLS. The effectiveness of KD therapy and ASMs in this study was insufficient. • Infantile epileptic spasms syndrome with Leigh and Leigh-like syndromes case series. • Four of 9 patients treated with ACTH achieved electroclinical remission < 1 month. • One of seven treated with ketogenic diet (KD) achieved electroclinical remission. • No patients treated with only ASMs achieved electroclinical remission. • Adverse events were reported in 4 with ACTH, none with KD, and 8 with ASMs. [ABSTRACT FROM AUTHOR]

• The seizure type characterized by generalized myoclonic seizure, closely followed by tonic seizure, is designated as MT seizure. • MT seizures predominantly occurred during the sleep period, with male patients constituting a majority of the participants. • The prognosis of Generalized Epilepsy with MT seizure was found to be more favorable compared to other types of epilepsy. To test the hypothesis that myoclonic seizures can evolve to tonic seizures, we documented the electroclinical features of this under-recognized seizure type. We observed a distinct seizure pattern starting with myoclonus without returning to an interictal state, which subsequently evolved into generalized tonic seizures. The detailed symptomatic and electroencephalographic characteristics of this seizure were extracted, and the clinical manifestations, drug curative responses in patients with this seizure were reviewed and analyzed. The onset of all seizures was characterized by a preceding period of myoclonus and bursts of generalized spike or poly-spike slow wave discharges with high amplitude. This was closely followed by the occurrence of tonic seizures, which were distinguished by bursts of generalized fast activity at 10 Hz or higher frequency. This under-recognized seizure type has been designated as myoclonic-to-tonic (MT) seizure. The number of patients identified with MT seizures in this study was 34. The prevalence rate of MT seizures was found to be higher in males. While MT seizures typically included a tonic component, it should be noted that some patients experiencing this seizure type never presented with isolated tonic seizures. Generalized Epilepsy not further defined (GE) accounted for approximately one-third of the diagnosed cases, followed by Lennox-Gastaut syndrome and Epilepsy with Myoclonic-Atonic seizures. In comparison to other types of epilepsy, GE with MT seizures demonstrated a more favorable prognosis. The classification of myoclonic-to-tonic seizure represents a novel approach in comprehending the ictogenesis of generalized seizures and can provide valuable assistance to clinicians in epilepsy diagnosis. [ABSTRACT FROM AUTHOR]

Purpose: To assess preferences and outcome expectations for vagus nerve stimulation (VNS) and corpus callosotomy (CC) surgeries in the treatment of atonic seizure in Lennox-Gastaut syndrome (LGS). Methods: A total of 260 surveys were collected from patients are caregivers of LGS patients via Research Electronic Data Capture (REDCap). Results: Respondents reported an average acceptable atonic seizure reduction rate of 55.9% following VNS and 74.7% following CC. 21.3% (n = 50) were willing to be randomized. Respondents reported low willingness for randomization and a higher seizure reduction expectation with CC. Conclusion: Our findings guide surgical approaches for clinicians to consider patient preference in order to design future studies comparing effectiveness between these two procedures. [ABSTRACT FROM AUTHOR]

This article explores the challenges of treating epilepsy and the high prevalence of treatment failure. It suggests that a lack of understanding of why medications fail or why side effects occur is a major obstacle to successful treatment. The article emphasizes the need to identify the basis for treatment failure in order to develop more effective treatments. It also discusses different patterns of treatment failure and highlights the need for new approaches to discovery and a better understanding of treatment failure mechanisms. [Extracted from the article]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

CDKL5 deficiency disorder (CDD) is a complex clinical condition resulting from non-functional or absent CDKL5 protein, a serine–threonine kinase pivotal for neural maturation and synaptogenesis. The disorder manifests primarily as developmental epileptic encephalopathy, with associated neurological phenotypes, such as hypotonia, movement disorders, visual impairment, and gastrointestinal issues. Its prevalence is estimated at 1 in 40,000–60,000 live births, and it is more prevalent in females due to the lethality of germline mutations in males during fetal development. This Italian multi-center observational study focused on 34 patients with CDKL5-related epileptic encephalopathy, aiming to enhance the understanding of the clinical and molecular aspects of CDD. The study, conducted across 14 pediatric neurology tertiary care centers in Italy, covered various aspects, including phenotypic presentations, seizure types, EEG patterns, treatments, neuroimaging findings, severity of psychomotor delay, and variant-phenotype correlations. The results highlighted the heterogeneity of seizure patterns, with hypermotor-tonic-spasms sequence seizures (HTSS) noted in 17.6% of patients. The study revealed a lack of clear genotype–phenotype correlation within the cohort. The presence of HTSS or HTSS-like at onset resulted a negative prognostic factor for the presence of daily seizures at long-term follow-up in CDD patients. Despite extensive polypharmacotherapy, including medications such as valproic acid, clobazam, cannabidiol, and others, sustained seizure freedom proved elusive, affirming the inherent drug-resistant nature of CDD. The findings underscored the need for further research to explore response rates to different treatments and the potential role of non-pharmacological interventions in managing this challenging disorder. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the Refractory Epilepsy Screening Tool for Lennox–Gastaut Syndrome (REST‐LGS) for real‐world identification of LGS in adults and to develop a scoring system for the tool. Methods: A retrospective chart review of adults with drug resistant epilepsy (DRE) and intellectual development disorder (IDD) was conducted by 2 primary care providers blinded to diagnosis. The REST‐LGS was designed via the Modified Delphi Consensus and was previously validated. This tool consists of 8 criteria (4 major, 4 minor) considered indicative of LGS. To account for missing data in the earlier validation study and to evaluate applicability in a real‐world setting, the REST‐LGS was refined to include a scoring system in which major criteria were more heavily weighted than minor criteria, producing categories of "likely" (>11 points), "possible" (8–11 points), and "unlikely" (<8 points) LGS. Statistical analyses were descriptive. Results: Of the 100 patients included in the analysis, data for slow spike–waves in electroencephalography and seizure onset age – both major REST‐LGS criteria – were missing for 46% and 42% of patients, respectively. The majority of patients met 4 of the 8 REST‐LGS criteria (cognitive impairment since childhood, 71%; persistent seizures despite a trial of ≥2 antiseizure medications, 65%; seizure onset before the age of 12 years, 57%; ≥2 seizure types, 56%). All 4 major criteria were met in 22 patients (22%). The percentages of patients considered "likely," "possible," or "unlikely" to have LGS were 26%, 30%, and 44%, respectively. Of the 74 patients without a previous LGS diagnosis, 42 (57%) were identified as "possible" or "likely" to have LGS using REST‐LGS. Significance: In this analysis, the validated REST‐LGS was evaluated in a real‐world setting. The majority of previously undiagnosed patients were identified via REST‐LGS as "possible" or "likely" to have LGS. Extensive missing data highlights challenges of LGS diagnosis in adults. Plain Language Summary: There is a need to identify adult patients with Lennox–Gastaut syndrome (LGS) so they can receive appropriate treatment. The Refractory Epilepsy Screening Tool for LGS (REST‐LGS) questionnaire was designed by experts to identify whether patients with seizures that are not controlled by medications may have LGS. In this study, 2 physicians completed the REST‐LGS using charts for 100 patients who experience seizures not controlled by medications. Of the patients who were previously diagnosed as not having LGS, the majority were "likely" or "possible" to have LGS based on the REST‐LGS; therefore, the REST‐LGS can identify patients for further evaluation. [ABSTRACT FROM AUTHOR]

Lennox–Gastaut syndrome (LGS) is a severe developmental and epileptic encephalopathy characterized by drug-resistant seizures, cognitive impairments, and abnormal electroencephalographic patterns. Vagus nerve stimulation (VNS) is a widely used neuromodulation therapy for LGS, but its effects on seizure outcomes, different seizure types, non-seizure outcomes, and adverse events in this population have not been comprehensively reviewed. To conduct a scoping review on the use of VNS in LGS, a literature search was performed in PubMed, OVID, Web of Science, and Embase from inception to 9 June 2024, using relevant keywords and without restrictions on study design. The search yielded forty eligible studies (twenty-four retrospective cohorts, fourteen prospective cohorts, and two registry analyses) comprising 1400 LGS patients treated with VNS. No randomized controlled trials were identified. Across studies, the median seizure reduction ranged from 20.6% to 65%, with 0% to 100% of patients achieving a ≥50% seizure reduction. No consistent preoperative biomarker of VNS responsiveness was identified in LGS. Although inconsistent among different studies, tonic, atonic, and tonic–clonic seizures responded best, while focal seizures responded worst. Improvements in seizure severity, alertness, and quality of life were reported in some studies, but cognitive and adaptive functioning generally remained unchanged. Adverse events were mostly mild and transient, including hoarseness, cough, and paresthesia. Device-related complications and infections were uncommon. In conclusion, further research is needed to better understand VNS's position in the evolving LGS treatment landscape and its cost effectiveness. [ABSTRACT FROM AUTHOR]

Purpose: To assess the utility of electroretinogram (ERG) as a screening tool for vigabatrin-induced retinal toxicity in children with infantile spasms. Methods: This was an observational cohort study including children with infantile spasms receiving treatment with vigabatrin. A 30-Hz flicker potential ERG, using the RETeval system (LKC Technologies), was done at baseline before starting vigabatrin at 6 months and 1 year. The amplitudes were recorded. Results: Eleven children were included in the study. The most common etiologic factor for infantile spasms was tuberous sclerosis (36.4%) followed by West syndrome (27.3%). The mean age of the children was 7.14 ± 2.9 months, with a range of 3 to 16 months. The mean difference in amplitude was 3.21 ± 2.45 and 5.72 ± 4.18 µV at 6 and 12 months follow-up, respectively (P <.001). Eight of the 11 children (72.7%) showed vigabatrin-induced retinal toxicity, and all 8 children were receiving vigabatrin for more than 6 months. Conclusions: ERG can be used for vigabatrin-induced retinal toxicity monitoring in children with infantile spasms. Vigabatrin-induced retinal toxicity is related to the duration of treatment rather than cumulative dosage. [J Pediatr Ophthalmol Strabismus. 2024;61(4):273–278.] [ABSTRACT FROM AUTHOR]

Background: Neither radiological phenotypic characteristics nor reconstruction CT scan has been used to study the early anatomical disruption of the cranial bone in children with the so-called idiopathic type of West syndrome. Material and Methods: The basic diagnostic measures and the classical antiepileptic treatments were applied to these children in accordance with the conventional protocol of investigations and treatment for children with West syndrome. Boys from three unrelated families were given the diagnosis of the idiopathic type of West syndrome, aged 7, 10 and 12 years old. Parents underwent extensive clinical examinations. Three parents (age range of 28–41 year) were included in this study. All children showed a history of intellectual disabilities, cryptogenic epileptic spasms and fragmented hypsarrhythmia. These children and their parents were referred to our orthopedic departments because of variable skeletal deformities. Variable forms of skeletal deformities were the motive for the families to seek orthopedic advice. A constellation of flat foot, torticollis and early-onset osteoarthritis were observed by the family doctor. Apparently, and from the first clinical session in our practice, we felt that all these children are manifesting variable forms of abnormal craniofacial contour. Thereby, we immediately performed detailed cranial radiological phenotypic characterization of every affected child, as well as the siblings and parents, and all were enrolled in this study. All affected children underwent whole-exome sequence analysis. Results: The craniofacial phenotype of all children revealed apparent developmental anatomical disruption of the cranial bones. Palpation of the skull bones showed unusual palpable bony ridges along different sutural locations. A 7-year-old child showed abnormal bulging over the sagittal suture, associated with bilateral bony ridges over the squamosal sutures. AP skull radiograph of a 7-year-old boy with West syndrome showed facial asymmetry with early closure of the metopic suture, and other sutures seemed ill-defined. A 3D reconstruction CT scan of the skull showed early closure of the metopic suture. Another 3D reconstruction CT scan of the skull while the patient was in flexion showed early closure of the squamosal sutures, pressing the brain contents upward, causing the development of a prominent bulge at the top of the mid-sagittal suture. A reformatted 3D reconstruction CT scan confirmed the bilateral closure of the squamosal suture. Examination of the parents revealed a similar skull radiographic abnormality in his mother. A 3D reformatted frontal cranial CT of a 35-year-old mother showed early closure of the metopic and sagittal sutures, causing a mid-sagittal bony bulge. A 10-year-old boy showed an extremely narrow frontal area, facial asymmetry and a well palpable ridge over the lambdoid sutures. A 3D axial reconstruction CT scan of a 10-year-old boy with West syndrome illustrated the asymmetry of the posterior cranial bones along the lambdoid sutures. Interestingly, his 28-year-old mother has been a client at the department of spine surgery since she was 14 years old. A 3D reconstruction CT scan of the mother showed a noticeable bony ridge extending from the metopic suture upwards to involve the sagittal suture (red arrow heads). The black arrow shows a well demarcated bony ridge over the squamosal suture. A 3D reconstruction CT scan of the skull and spine showed the thick bony ridge of the metopic and the anterior sagittal as well as bilateral involvement of the squamosal, causing apparent anterior narrowing of the craniofacial contour. Note the lumbar scoliosis. A 12-year-old boy showed brachycephaly. A lateral skull radiograph of a 12-year-old boy with West syndrome showed premature sutural fusion, begetting an abnormal growth pattern, resulting in cranial deformity. The nature of the deformity depends on which sutures are involved, the time of onset and the sequence in which individual sutures fuse. In this child, brachycephalic secondary to craniosynostosis, which occurred because of bilateral early ossification of the coronal sutures, led to bi-coronal craniosynostosis. Thickened frontal bones and an ossified interclinoid ligament of the sella turcica were encountered. The lateral skull radiograph of a 38-year-old mother with a history of poor schooling achievements showed a very similar cranial contour of brachycephaly, thickening of the frontal bones and massive ossification of the clinoid ligament of the sella turcica. Maternal history revealed a history of multiple spontaneous miscarriages in the first trimester of more than five times. Investigating his parents revealed a brachycephalic mother with borderline intelligence. We affirm that the pattern of inheritance in the three boys was compatible with the X-linked recessive pattern of inheritance. Whole-exome sequencing showed non-definite phenotype/genotype correlation. Conclusions: The aim of this study was sixfold: firstly, to refute the common usage of the term idiopathic; secondly, we feel that it could be possible that West syndrome is a symptom complex rather than a separate diagnostic entity; thirdly, to further detect the genetic carrier, we explored the connection between the cranial bones in children with West syndrome with what has been clinically observed in their parents; fourthly, the early life anatomical disruptions of the cranial bones among these children seem to be heterogeneous; fifthly, it shows that the progressive deceleration in the development of this group of children is highly connected to the progressive closure of the cranial sutures; sixthly, we affirm that our findings are novel. [ABSTRACT FROM AUTHOR]

Introduction: Although the contribution of enhanced glial activity in seizure induction is increasingly recognized, the role of glia-induced neuroinflammation in the physiopathology of epileptic encephalopathy (EE) has been scarcely investigated. Methods: To delineate the contribution of glial activity in EE, we measured levels of glia-derived mediators with previously described biomarker value, including glial fibrillary acidic protein (GFAP), high mobility group box 1 (HMGB1), chitinase-3-like protein 1 (CHI3L1), soluble CD163 (sCD163) and triggering receptor expressed on myeloid cells 2 (TREM2) by ELISA in sera of patients with idiopathic West syndrome (WS, n=18), idiopathic Lennox-Gastaut syndrome (LGS, n=13) and healthy controls (n=31). Results: Patients with EE showed significantly higher CHI3L1 levels compared to healthy controls. Levels of HMGB1, CHI3L1, sCD163 and TREM2 were higher in LGS patients than WS patients and/or healthy controls. One or more of the investigated mediators were associated with treatment responsiveness, disease severity and presence of pathological features on electroencephalography (EEG). Conclusions: To our knowledge, our findings provide the initial patient-based evidence that astrocyte- and microglia-mediated neuroinflammation might be involved in the pathogenesis of LGS and WS. Moreover, glial mediators may serve as prognostic biomarkers in patients with idiopathic EE. [ABSTRACT FROM AUTHOR]

Objective: Infantile epileptic spasms syndrome (IESS) is a common and urgent diagnosis with seizure and nonseizure mimics. Evaluation with prolonged video–electroencephalography (EEG) can be time‐consuming and costly. This study investigated the use of EEG review of a single sleep–wake cycle to exclude IESS. Methods: We retrospectively reviewed video‐EEG studies to rule out IESS in children between the ages of 2 months and 2 years in the period from January 2019 through June 2020. EEG studies were reviewed from the start of the recording through the first sleep–wake cycle and scored as "normal," "consistent with IESS," or "abnormal but not diagnostic of IESS." Scores were compared to the clinical report created by analysis of the entire video‐EEG. Results: Inclusion criteria were met in 238 EEG studies. The mean patient age was 7.6 months. The median duration of the full study was 908 min, compared to 107.5 min for the first sleep–wake cycle only. The median difference in recording time was 801 min, p‐value <.01. Scored outcomes were similar. Sixty‐eight percent of EEG studies were scored as "normal" on first sleep–wake cycle review as compared to 63% on full study review, 13% scored as "consistent with IESS" compared to 16% and 19% scored as "abnormal but not diagnostic of IESS" compared to 21%. Sensitivity and specificity of the first sleep–wake cycle review for studies "consistent with IESS" was 84% and 100%, respectively. No cases of IESS were scored as normal on first sleep–wake cycle review. Significance: A single sleep–wake cycle captured on EEG can triage studies when IESS is suspected. A normal first sleep–wake cycle did not miss cases of IESS and could result in reduced EEG recording time. Because most of these cases presented to an emergency department, a normal first sleep–wake cycle may help providers determine the acuity, or necessity, of further testing. [ABSTRACT FROM AUTHOR]

Introduction: The efficacy of stiripentol in Dravet syndrome children was evidenced in two randomized, double-blind, placebo-controlled, phase 3 studies, namely STICLO France (October 1996–August 1998) and STICLO Italy (April 1999–October 2000), but data were not fully exploited at the time. Methods: This post-hoc analysis used additional information, notably collected during the open-label extension (OLE) month, or reported by caregivers in individual diaries, to evaluate new outcomes. Results: Overall, 64 patients were included (31 in the placebo group, 33 in the stiripentol group) of whom 34 (53.1%) were female. Patients' mean and median (25%; 75%) age were 9.2 years (range 3.0–20.7 years) and 8.7 years (6.0; 12.1) respectively. At the end of the double-blind treatment period, 72% of the patients in the stiripentol group had a ≥ 50% decrease in generalized tonic–clonic seizure (GTCS) frequency, versus 7% in the placebo group (P < 0.001), 56% had a profound (≥ 75%) decrease versus 3% in the placebo group (P < 0.001), and 38% were free of GTCS, but none in the placebo group (P < 0.001). The onset of stiripentol efficacy was rapid, significant from the fourth day of treatment onwards. The median longest period of consecutive days with no GTCS was 32 days in the stiripentol group compared to 8.5 days in the placebo group (P < 0.001). Further to the switch to the third month OLE, an 80.2% decrease in seizure frequency from baseline was observed in patients previously receiving placebo, while no change in efficacy was observed in those already on stiripentol. Adverse events were more frequent in the stiripentol group, with significantly more episodes of somnolence, anorexia, and weight decrease than in the placebo group. Conclusion: Altogether these new analyses of the STICLO data reinforce the evidence for a remarkable efficacy of stiripentol in Dravet syndrome, with a demonstrated rapid onset of action and sustained response, as also evidenced in further post-randomized trials. [ABSTRACT FROM AUTHOR]

This article discusses the successful use of cannabidiol (CBD) in the treatment of nonconvulsive status epilepticus (NCSE) in a patient with Angelman syndrome (AS). AS is a rare neurogenetic disorder characterized by developmental delay, seizures, cognitive impairment, and motor dysfunction. NCSE is a common complication in AS, and treatment options are limited. The patient in this case study was treated with Epidyolex® CBD, which resulted in improved responsiveness, seizure freedom, and significant improvement in EEG abnormalities. The use of CBD in refractory status epilepticus has shown favorable outcomes in previous studies. While this case study is anecdotal, it suggests that CBD may be a promising treatment for NCSE in AS and warrants further research and clinical trials. [Extracted from the article]

Lennox-Gastaut syndrome (LGS) is a severe, epileptic encephalopathy.In recent years, a variety of drugs have been approved for the treatment of LGS. The U.S. Food and Drug Administration approved clobazam and cannabidiol as adjunctive therapy for LGS in October 2011 and June 2018, respectively. This article provides an overview of clobazam and cannabidiol, including their chemical structures, pharmacological actions, curative effects, safety profile, drug interactions, to introduce the current state of research and the achievements of both drugs.

Abstract Objective Lennox‐Gastaut syndrome (LGS) is an archetypal developmental and epileptic encephalopathy, for which novel treatments are emerging. Diagnostic criteria for LGS have recently been defined by the International League Against Epilepsy (ILAE). We aimed to apply these criteria in a real‐world setting. Methods We applied ILAE diagnostic criteria to a cohort of patients diagnosed with LGS by epileptologists following inpatient video‐EEG monitoring (VEM) at tertiary comprehensive epilepsy centers between 1995 and 2015. We also assessed mortality in this cohort. Results Sixty patients diagnosed with LGS and had complete records available for review were identified. Among them, 29 (48%) patients met ILAE diagnostic criteria for LGS (ILAE‐DC group). Thirty‐one did not meet criteria (non‐ILAE‐DC) due to the absence of documented tonic seizures (n = 7), EEG features (n = 12), or both tonic seizures and EEG features (n = 10), intellectual disability (n = 1), or drug resistance (n = 1). The ILAE‐DC group had a shorter duration of epilepsy at VEM than the non‐ILAE‐DC group (median = 12.0 years vs. 23.7 years, respectively; p = 0.015). The proportions of patients with multiple seizure types (100% vs. 96.7%), ≤2.5 Hz slow spike‐and‐wave EEG activity (100% vs. 90%), seizure‐related injuries (27.6% vs. 25.8%), and mortality (standardized mortality ratio 4.60 vs. 5.12) were similar between the groups. Significance Up to 52% of patients diagnosed with LGS following VEM may not meet recently accepted ILAE criteria for LGS diagnosis. This may reflect both the limitations of retrospective medical record review and a historical tendency of applying the LGS diagnosis to a broad spectrum of severe, early‐onset drug‐resistant epilepsies with drop attacks. The ILAE criteria allow the delineation of LGS based on distinct electroclinical features, potentiating accurate diagnosis, prognostication, and management formulation. Nonetheless, mortality outcomes between those who did and did not meet ILAE diagnostic criteria for LGS were similarly poor, and both groups suffered high rates of seizure‐related injury. Plain Language Summary More than half of patients diagnosed with Lennox‐Gastaut Syndrome (LGS) at three Australian epilepsy monitoring units between 1995 and 2015 did not meet the recently devised International League Against Epilepsy (ILAE) diagnostic criteria for LGS. Mortality was equally high in those who did and did not meet the ILAE diagnostic criteria, and seizure‐related injury was common. The ILAE diagnostic criteria will guide accurate diagnosis, management, prognostication, and research in patients with LGS, however may be limited in their practical application to patients with a longer duration of epilepsy, or to those for whom detailed assessment is difficult.

Abstract Objective Evaluate the long‐term efficacy of vagus nerve stimulation (VNS) in patients with developmental and epileptic encephalopathies (DEE) compared with epilepsy patients without intellectual disability (ID). Methods Long‐term outcomes from a Norwegian VNS quality registry are reported in 105 patients with DEEs (Lennox–Gastaut syndrome [LGS] n = 62; Dravet n = 16; Rett n = 9; other syndromes n = 18) were compared with 212 epilepsy patients without ID, with median follow‐up of 88 and 72 months, respectively. Total seizure reduction was evaluated at 6, 12, 24, 36, and 60 months. Effect on different seizure types was evaluated at baseline and last observation carried forward (LOCF). Results Median monthly seizure frequency at LOCF was reduced by 42.2% (p

Abstract Background RARS2-related mitochondrial disorder is an autosomal recessive mitochondrial encephalopathy caused by biallelic pathogenic variants in the gene encoding the mitochondrial arginyl-transfer RNA synthetase 2 (RARS2, MIM *611524, NM_020320.5). RARS2 catalyzes the transfer of L-arginine to its cognate tRNA during the translation of mitochondrially-encoded proteins. The classical presentation of RARS2-related mitochondrial disorder includes pontocerebellar hypoplasia (PCH), progressive microcephaly, profound developmental delay, feeding difficulties, and hypotonia. Most patients also develop severe epilepsy by three months of age, which consists of focal or generalized seizures that frequently become pharmacoresistant and lead to developmental and epileptic encephalopathy (DEE). Case presentation Here, we describe a six-year-old boy with developmental delay, hypotonia, and failure to thrive who developed an early-onset DEE consistent with Lennox-Gastaut Syndrome (LGS), which has not previously been observed in this disorder. He had dysmorphic features including bilateral macrotia, overriding second toes, a depressed nasal bridge, retrognathia, and downslanting palpebral fissures, and he did not demonstrate progressive microcephaly. Whole genome sequencing identified two variants in RARS2, c.36 + 1G > T, a previously unpublished variant that is predicted to affect splicing and is, therefore, likely pathogenic and c.419 T > G (p.Phe140Cys), a known pathogenic variant. He exhibited significant, progressive generalized brain atrophy and ex vacuo dilation of the supratentorial ventricular system on brain MRI and did not demonstrate PCH. Treatment with a ketogenic diet (KD) reduced seizure frequency and enabled him to make developmental progress. Plasma untargeted metabolomics analysis showed increased levels of lysophospholipid and sphingomyelin-related metabolites. Conclusions Our work expands the clinical spectrum of RARS2-related mitochondrial disorder, demonstrating that patients can present with dysmorphic features and an absence of progressive microcephaly, which can help guide the diagnosis of this condition. Our case highlights the importance of appropriate seizure phenotyping in this condition and indicates that patients can develop LGS, for which a KD may be a viable therapeutic option. Our work further suggests that analytes of phospholipid metabolism may serve as biomarkers of mitochondrial dysfunction.

Surgical management of pediatric patients with nonlesional, drug-resistant epilepsy, including patients with Lennox-Gastaut syndrome (LGS), remains a challenge given the lack of resective targets in most patients and shows seizure freedom rates <50% at 5 years. The efficacy of deep brain stimulation (DBS) is less certain in children than in adults. This study examined clinical and seizure outcomes for pediatric patients with LGS undergoing DBS targeting of the centromedian thalamic nuclei (CMTN). An institutional review board–approved retrospective analysis was performed of patients aged ≤19 years with clinical diagnosis of LGS undergoing bilateral DBS placement to the CMTN from 2020 to 2021 by a single surgeon. Four females and 2 males aged 6–19 years were identified. Before surgery, each child experienced at least 6 years of refractory seizures; 4 children had experienced seizures since infancy. All took antiseizure medications at the time of surgery. Five children had previous placement of a vagus nerve stimulator and 2 had a previous corpus callosotomy. The mean length of stay after DBS was 2 days. No children experienced adverse neurologic effects from implantation; the mean follow-up time was 16.3 months. Four patients had >60% reduction in seizure frequency after surgery, 1 patient experienced 10% reduction, and 1 patient showed no change. No children reported worsening seizure symptoms after surgery. Our study contributes to the sparse literature describing CMTN DBS for children with drug-resistant epilepsy from LGS. Our results suggest that CMTN DBS is a safe and effective therapeutic modality that should be considered as an alternative or adjuvant therapy for this challenging patient population. Further studies with larger patient populations are warranted. [ABSTRACT FROM AUTHOR]

The mediator complex subunit 23 (MED23) gene encodes a protein that acts as a tail module mediator complex, a multi-subunit co-activator involved in several cellular activities. MED23 has been shown to have substantial roles in myogenesis and other molecular mechanisms. The functions of MED23 in the neurological system remain unclear and the clinical phenotype is not thoroughly described. Whole exome sequencing was used to identify a novel mutation in the MED23 gene. DNA capture probes using next-generation sequencing-based copy number variation analysis with Illumina array were performed. The clinical, demographic, neuroimaging, and electrophysiological data of the patients were collected, and similarly, the data of all reported cases in the literature were extracted to compare findings. Screening a total of 9,662 articles, we identified 22 main regulatory processes for the MED23 gene, including suppressive activity for carcinogenic processes. MED23 is also involved in the brain’s neurogenesis and functions. The identified cases mainly presented with intellectual disability (87.5%) and developmental delay (50%). Seizures were present in only 18.75% of the patients. Slow backgrounds and spike and sharp-wave complexes were reported on the electroencephalogram (EEG) of a few patients and delayed myelination, thin corpus callosum, and pontine hypoplasia on magnetic resonance imaging (MRI). The MED23 gene regulates several processes in which its understanding promotes considerable therapeutic potential for patients. It is crucial to consider genetic and laboratory testing, particularly when encountering potential carriers. Intellectual disability and developmental delay are the most notable clinical signs with heterogeneous features on EEG and MRI. [ABSTRACT FROM AUTHOR]

Interest in using cannabis products for a medical purpose in children under the age of 18 years is increasing. There are many medical cannabis products available that can include cannabidiol (CBD) or delta-9-tetrahydrocannabinol (THC), or both. Despite many therapeutic claims, there are few rigorous studies to inform the dosing, safety, and efficacy of medical cannabis in paediatric clinical practice. This statement reviews the current evidence and provides recommendations for using medical cannabis in children. Longer-term (2-year) reports support the sustained tolerability and efficacy of cannabidiol therapy for patients with Lennox-Gastaut and Dravet syndromes. CBD-enriched cannabis extracts containing small amounts of THC have been evaluated in a small number of paediatric patients, and further research is needed to inform clinical practice guidelines. Given the widespread use of medical cannabis in Canada, paediatricians should be prepared to engage in open, ongoing discussions with families about its potential benefits and risks, and develop individualized plans that monitor efficacy, reduce harms, and mitigate drug–drug interactions. [ABSTRACT FROM AUTHOR]

It has been several years since highly purified cannabidiol (CBD) was registered as a medication that can be used in children of at least 2 years of age to treat different types of seizures related to Lennox–Gastaut syndrome (LGS), Dravet syndrome (DS), and more recently tuberous sclerosis complex (TSC). During this time, 39 randomized clinical trials (RCTs) and 13 meta-analyses on the efficacy and safety of CBD treatment have been published. Each of the meta-analyses had its own criteria for the RCTs' inclusion and, therefore, slightly different interpretations of the analyzed data. Each of them contributed in its own way to the understanding of CBD pharmacology, mechanisms of therapeutic action, development of adverse reactions, and drug–drug interactions. Hence, it seemed reasonable to gather the most relevant data in one article and present all the current knowledge on the use of CBD in epilepsy. The results of the 13 meta-analyses presented herein confirmed the effectiveness and safety of CBD in children and adolescents with DREs. In adults, reliable conclusions cannot be drawn due to insufficient data. [ABSTRACT FROM AUTHOR]

AMPA (α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid) receptors (AMPARs) mediate fast excitatory neurotransmission in the brain. AMPARs form by homo- or heteromeric assembly of subunits encoded by the GRIA1 – GRIA4 genes, of which only GRIA3 is X-chromosomal. Increasing numbers of GRIA3 missense variants are reported in patients with neurodevelopmental disorders (NDD), but only a few have been examined functionally. Here, we evaluated the impact on AMPAR function of one frameshift and 43 rare missense GRIA3 variants identified in patients with NDD by electrophysiological assays. Thirty-one variants alter receptor function and show loss-of-function or gain-of-function properties, whereas 13 appeared neutral. We collected detailed clinical data from 25 patients (from 23 families) harbouring 17 of these variants. All patients had global developmental impairment, mostly moderate (9/25) or severe (12/25). Twelve patients had seizures, including focal motor (6/12), unknown onset motor (4/12), focal impaired awareness (1/12), (atypical) absence (2/12), myoclonic (5/12) and generalized tonic-clonic (1/12) or atonic (1/12) seizures. The epilepsy syndrome was classified as developmental and epileptic encephalopathy in eight patients, developmental encephalopathy without seizures in 13 patients, and intellectual disability with epilepsy in four patients. Limb muscular hypotonia was reported in 13/25, and hypertonia in 10/25. Movement disorders were reported in 14/25, with hyperekplexia or non-epileptic erratic myoclonus being the most prevalent feature (8/25). Correlating receptor functional phenotype with clinical features revealed clinical features for GRIA3 -associated NDDs and distinct NDD phenotypes for loss-of-function and gain-of-function variants. Gain-of-function variants were associated with more severe outcomes: patients were younger at the time of seizure onset (median age: 1 month), hypertonic and more often had movement disorders, including hyperekplexia. Patients with loss-of-function variants were older at the time of seizure onset (median age: 16 months), hypotonic and had sleeping disturbances. Loss-of-function and gain-of-function variants were disease-causing in both sexes but affected males often carried de novo or hemizygous loss-of-function variants inherited from healthy mothers, whereas affected females had mostly de novo heterozygous gain-of-function variants. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Introduction. Drug-resistant epilepsy (DRE) remains poorly-controlled in c.33% of patients, and up to 50% of patients suffering from DRE are deemed not to be suitable candidates for resective surgery. For these patients, deep brain stimulation (DBS) may constitute the last resort in the treatment of DRE. State of the art. We undertook a systematic review of the current literature on DBS efficacy and the safety of two thalamic nuclei--anterior nucleus of the thalamus (ANT) and the centromedian nucleus of the thalamus in the management of patients with DRE. A search using two electronic databases, the Medical Literature, Analysis, and Retrieval System on-line (MEDLINE) and the Cochrane Central Register of Controlled Trials (CEN-TRAL) was conducted. Clinical implications. We found 30 articles related to ANT DBS and 13 articles related to CMN DBS which were further analysed. Based on the clinical research articles, we found a mean seizure frequency reduction for both thalamic nuclei. For ANT DBS, the mean seizure frequency reduction ranged from 48% to 75%, and for CMN DBS from 46.7% to 91%. The responder rate (defined as at least 50% reduction in seizure frequency) was reported to be 53.2-75% for patients after ANT DBS and 50--90% for patients after CMN DBS. Future directions. ANT and CMN DBS appear to be safe and efficacious treatments, particularly in patients with refractory partial seizures and primary generalised seizures. ANT DBS reduces most effectively seizures originating in the temporal and frontal lobes. CMN DBS reduces mostly primary generalised tonic-clonic and atypical absences and atonic seizures. Seizures related to Lennox-Gastaut syndrome respond very favourably to CMN DBS. [ABSTRACT FROM AUTHOR]

Children receiving palliative care have life-limiting or life-threatening conditions, which include symptoms ranging from unpleasant to intolerable suffering. We describe three diverse cases of medical marijuana within ambulatory pediatric palliative care, highlighting use for spasticity, refractory seizures, and cancer-related symptoms. Included are caregiver perspectives of their child's experience with medical marijuana. This population has high potential for positive effects from medical marijuana therapy, particularly for maximizing quality of life. [ABSTRACT FROM AUTHOR]

Aim: To differentiate phenotypic features of individuals with CDKL5 deficiency disorder (CDD) from those of individuals with other infantile‐onset epilepsies. Method: We performed a retrospective cohort study and ascertained individuals with CDD and comparison individuals with infantile‐onset epilepsy who had epilepsy gene panel testing. We reviewed records, updated variant classifications, and compared phenotypic features. Wilcoxon rank‐sum tests and χ2 or Fisher's exact tests were performed for between‐cohort comparisons. Results: We identified 137 individuals with CDD (110 females, 80.3%; median age at last follow‐up 3 year 11 months) and 313 individuals with infantile‐onset epilepsies (156 females, 49.8%; median age at last follow‐up 5 years 2 months; 35% with genetic diagnosis). Features reported significantly more frequently in the CDD group than in the comparison cohort included developmental and epileptic encephalopathy (81% vs 66%), treatment‐resistant epilepsy (95% vs 71%), sequential seizures (46% vs 6%), epileptic spasms (66% vs 42%, with hypsarrhythmia in 30% vs 48%), regression (52% vs 29%), evolution to Lennox–Gastaut syndrome (23% vs 5%), diffuse hypotonia (72% vs 36%), stereotypies (69% vs 11%), paroxysmal movement disorders (29% vs 17%), cerebral visual impairment (94% vs 28%), and failure to thrive (38% vs 22%). Interpretation: CDD, compared with other suspected or confirmed genetic epilepsies presenting in the first year of life, is more often characterized by a combination of treatment‐resistant epilepsy, developmental and epileptic encephalopathy, sequential seizures, spasms without hypsarrhythmia, diffuse hypotonia, paroxysmal movement disorders, cerebral visual impairment, and failure to thrive. Defining core phenotypic characteristics will improve precision diagnosis and treatment. [ABSTRACT FROM AUTHOR]

Objective: Lead time to treatment (clinical onset of epileptic spasms [ES] to initiation of appropriate treatment) is known to predict outcomes in infantile epileptic spasms syndrome (IESS). Timing the clinical onset of ES is crucial to establish lead time. We investigated how often ES onset could be established to the nearest week. We aimed to (1) ascertain the exact date or estimate the nearest week of ES onset and (2) compare clinical/demographic factors between patients where date of ES onset was determined or estimated to the nearest week and patients whose date of ES onset could not be estimated to the nearest week. Reasons for difficulties in estimating date of ES onset were explored. Methods: Retrospective chart review of new onset IESS patients (January 2019–May 2022) extracted the date or week of the clinical onset of ES. Predictors of difficulty in date of ES onset estimation to the nearest week were examined by regression analysis. Sources contributing to difficulties determining date of ES onset were assessed after grouping into categories (provider‐, caregiver‐, disease‐related). Results: Among 100 patients, date of ES onset was estimated to the nearest week in 47%. On univariable analysis, age at diagnosis (p =.021), development delay (p =.007), developmental regression/stagnation (p =.021), ES intermixed with other seizures (p =.011), and nonclustered ES at onset (p =.005) were associated with difficulties estimating date of ES onset. On multivariable analysis, failure to establish date of ES onset was related to ES intermixed with other seizures (p =.004) and nonclustered ES at onset (p =.003). Sources contributing to difficulties determining date of ES onset included disease‐related factors (ES characteristics, challenges interpreting electroencephalograms) and provider/caregiver‐related factors (delayed diagnosis). Significance: Difficulties with estimation of lead time (due to difficulties timing ES onset) can impact clinical care (prognostication), as even small increments in lead time duration can have adverse developmental consequences. [ABSTRACT FROM AUTHOR]

Objective: Evaluate the long‐term efficacy of vagus nerve stimulation (VNS) in patients with developmental and epileptic encephalopathies (DEE) compared with epilepsy patients without intellectual disability (ID). Methods: Long‐term outcomes from a Norwegian VNS quality registry are reported in 105 patients with DEEs (Lennox–Gastaut syndrome [LGS] n = 62; Dravet n = 16; Rett n = 9; other syndromes n = 18) were compared with 212 epilepsy patients without ID, with median follow‐up of 88 and 72 months, respectively. Total seizure reduction was evaluated at 6, 12, 24, 36, and 60 months. Effect on different seizure types was evaluated at baseline and last observation carried forward (LOCF). Results: Median monthly seizure frequency at LOCF was reduced by 42.2% (p < 0.001) in patients with DEE and by 55.8% (p < 0.001) in patients without ID. In DEE patients, ≥50% seizure reduction at 6 and 24 months were 17.1% and 37.1%, respectively, and 33.5% and 48.6% for patients without ID. Seizure reduction ≥75% at 60 months occurred in 14.3% of DEE patients and 23.1% of patients without ID. Highest median reduction was for atonic seizures, most notably 64.6% for LGS patients. A better effect was seen at 2 years among DEE patients with unchanged medication compared with those with changed medication (54.5% vs. 35.6% responders, p = 0.078). More DEE patients were reported to have greater improvement in ictal or postictal severity (43.8% vs. 28.3%, p = 0.006) and alertness (62.9% vs. 31.6%, p < 0.001) than patients without ID. For both groups, use of the magnet reduced seizure severity. Hoarseness was the most common adverse effect in both groups. In addition, DEE patients were frequently reported to have sleep disturbance, general discomfort, or abdominal problems. Significance: Our data indicate that VNS is very effective for atonic seizures. Patients without ID had best overall seizure reduction, however, patients with DEE had higher retention rates probably due to other positive effects. Plain Language Summary: DEE refers to a group of patients with severe epilepsy and intellectual disability. Many of these patients have restricted lifestyles with frequent seizures. VNS is a treatment option for patients who do not respond well to medicines, either because of insufficient effect or serious adverse effects. Our study shows that VNS is well tolerated in this patient group and leads to a reduction in all seizure types, most notably for seizures leading to fall. Many patients experience other positive effects like shorter and milder seizures, as well as improvement in alertness. [ABSTRACT FROM AUTHOR]

Objective: Lennox‐Gastaut syndrome (LGS) is an archetypal developmental and epileptic encephalopathy, for which novel treatments are emerging. Diagnostic criteria for LGS have recently been defined by the International League Against Epilepsy (ILAE). We aimed to apply these criteria in a real‐world setting. Methods: We applied ILAE diagnostic criteria to a cohort of patients diagnosed with LGS by epileptologists following inpatient video‐EEG monitoring (VEM) at tertiary comprehensive epilepsy centers between 1995 and 2015. We also assessed mortality in this cohort. Results: Sixty patients diagnosed with LGS and had complete records available for review were identified. Among them, 29 (48%) patients met ILAE diagnostic criteria for LGS (ILAE‐DC group). Thirty‐one did not meet criteria (non‐ILAE‐DC) due to the absence of documented tonic seizures (n = 7), EEG features (n = 12), or both tonic seizures and EEG features (n = 10), intellectual disability (n = 1), or drug resistance (n = 1). The ILAE‐DC group had a shorter duration of epilepsy at VEM than the non‐ILAE‐DC group (median = 12.0 years vs. 23.7 years, respectively; p = 0.015). The proportions of patients with multiple seizure types (100% vs. 96.7%), ≤2.5 Hz slow spike‐and‐wave EEG activity (100% vs. 90%), seizure‐related injuries (27.6% vs. 25.8%), and mortality (standardized mortality ratio 4.60 vs. 5.12) were similar between the groups. Significance: Up to 52% of patients diagnosed with LGS following VEM may not meet recently accepted ILAE criteria for LGS diagnosis. This may reflect both the limitations of retrospective medical record review and a historical tendency of applying the LGS diagnosis to a broad spectrum of severe, early‐onset drug‐resistant epilepsies with drop attacks. The ILAE criteria allow the delineation of LGS based on distinct electroclinical features, potentiating accurate diagnosis, prognostication, and management formulation. Nonetheless, mortality outcomes between those who did and did not meet ILAE diagnostic criteria for LGS were similarly poor, and both groups suffered high rates of seizure‐related injury. Plain Language Summary: More than half of patients diagnosed with Lennox‐Gastaut Syndrome (LGS) at three Australian epilepsy monitoring units between 1995 and 2015 did not meet the recently devised International League Against Epilepsy (ILAE) diagnostic criteria for LGS. Mortality was equally high in those who did and did not meet the ILAE diagnostic criteria, and seizure‐related injury was common. The ILAE diagnostic criteria will guide accurate diagnosis, management, prognostication, and research in patients with LGS, however may be limited in their practical application to patients with a longer duration of epilepsy, or to those for whom detailed assessment is difficult. [ABSTRACT FROM AUTHOR]