Short-term and long-term efficacy and safety of antiseizure medications in Lennox Gastaut syndrome: a network meta-analysis

Antiseizure medications for Lennox-Gastaut Syndrome: Comprehensive review and proposed consensus treatment algorithm

Lennox-Gastaut syndrome (LGS) is a severe, childhood-onset developmental and epileptic encephalopathy characterized by multiple drug-resistant seizure types, specific electroencephalogram (EEG) patterns, and significant cognitive and behavioral impairments. To date, eight anti-seizure medications (ASMs) have been specifically approved by the U.S. Food and Drug Administration (FDA) for the treatment of LGS: clonazepam, felbamate, lamotrigine, topiramate, rufinamide, clobazam, cannabidiol, and fenfluramine. Additionally, several other ASMs, including valproate, are frequently used off-label for LGS management. As the therapeutic landscape for LGS expands, clinicians are increasingly faced with complex decisions regarding optimal ASM selection. This narrative review explores evolving treatment strategies, offering a consensus-based treatment algorithm designed by a panel of U.S.- based experts. We analyze both FDA-approved and off-label ASMs, drawing on data from randomized controlled trials, open-label extensions, and real-world studies to assess each drug's efficacy and safety profile. A key challenge in comparing ASMs lies in the heterogeneity of study designs and outcome measures. This review addresses these limitations and considers crucial factors influencing ASM selection, such as seizure outcomes, safety profiles, cognitive and behavioral outcomes, drug-drug interactions, and rational polypharmacy. Barriers to access, including economic and regulatory hurdles, are also discussed. The proposed treatment algorithm emphasizes a personalized approach to LGS management, recommending valproate or clobazam as first-line treatments, followed by individualized combinations based on the specific patient profile and associated comorbidities.

Prolonged incubation with Δ9-tetrahydrocannabinol but not with cannabidiol induces synaptic alterations and mitochondrial impairment in immature and mature rat organotypic hippocampal slices

Cannabis derivatives are among the most widely used psychoactive substances in the world, which leads to growing medical concerns regarding its chronic use and abuse especially among adolescents. Exposure to THC during formative years produces long-term behavioral alterations that share similarities with symptoms of psychiatric and neurodevelopmental disorders. In this study, we have analyzed the functional and molecular mechanisms that might underlie these alterations. Rat organotypic hippocampal slices were cultured for 2 days (immature) or 10 days (mature) in vitro and then exposed for 7 days to THC (1 µM) or CBD (1 µM). At the end of the treatment, slices were analyzed by Western blotting, electrophysiological recordings, RT-PCR, and fluorescence microscopy to explore the molecular and functional changes in the hippocampus. A prolonged (7-day) exposure to THC reduced the expression levels of pre- (synaptophysin, vGlut1) and post-synaptic (PSD95) proteins in both immature and mature slices, whereas CBD significantly increased the expression levels of PSD95 only in immature slices. In addition, THC significantly reduced the passive properties and the intrinsic excitability of membranes and increased sEPSCs in CA1 pyramidal cells of immature but not mature slices. Exposure to both cannabinoids impaired mitochondrial function as detected by the reduction of mRNA expression levels of mitobiogenesis genes such as VDAC1, UCP2, and TFAM. Finally, THC but not CBD caused tissue disorganization and morphological modifications in CA1 pyramidal neurons, astrocytes and microglia in both immature and mature slices. These results are helpful to explain the specific vulnerability of adolescent brain to the effects of psychotropic cannabinoids.

Update on Cannabidiol in Drug-Resistant Epilepsy

Cannabidiol (CBD) has arisen as a promising therapeutic option for children with drug-resistant epilepsy (DRE). CBD has received regulatory nod from different regulatory authorities in the United States, Europe, and India for children with DRE particularly, Dravet syndrome (DS), Lennox Gastaut syndrome (LGS), and Tuberous sclerosis complex (TSC). Recent clinical trials and observational studies highlight the potential of CBD to lower seizure frequency and provide better quality of life in children affected by these disorders. The safety profile is generally favorable with minor common adverse events such as somnolence, diarrhea, and gastrointestinal issues. Furthermore, the expense associated with CBD remains a notable concern, especially in low- and middle-income countries such as India, where access to this promising treatment may be constrained. This draws attention to the cost-effective perspective of CBD. This review aims to explore the pharmacological properties of CBD, its mechanisms of action, and the clinical evidence supporting its use in various pediatric epilepsies, including LGS, DS, and TSC. Additionally, this review sheds light on the current regulatory landscape in India where CBD use is still in its nascent stages, and discusses the challenges and opportunities for integrating CBD into clinical practice.

First-choice hormonal therapies for children with infantile epileptic spasms syndrome in South Asia: A network meta-analysis of randomized controlled trials

Considering the peculiar challenges with infantile epileptic spasms syndrome (IESS) in South Asia and a wide variation in the usage of hormonal therapies, we compared the efficacy and safety of various hormonal therapies for children with IESS in South Asia. We searched PubMed, Embase, Scopus, and Web of Science databases from the inception until April 2024. We included only randomized clinical trials (RCTs) evaluating the efficacy and safety of hormonal therapies for IESS in the South Asian region. Complete cessation of epileptic spasms (ES), electro-clinical response, and time taken to be spasm-free at 2 or 6 weeks of therapy were efficacy outcomes, while the occurrence of adverse events was the safety outcome. Effect estimates were reported as odds ratio (OR) or mean difference (MD) with 95% confidence intervals (CI) and Cochrane risk of bias 2.0 (ROB 2.0) used for quality assessment of each study. The surface under the cumulative ranking curve (SUCRA) was used to rank the different therapies and reported as a p-score ranging from 0 to 1. Of 747 citations, nine RCTs comprising 566 children with IESS were included. After 2-week treatment, dexamethasone (OR: 6.72; 95% CI: 1.47, 30.72), adrenocorticotropic hormone therapy (ACTH) high dose (HD) (OR: 5.30; 95% CI: 1.05, 26.91), and prednisolone HD (OR: 2.41; 95% CI:1.07, 5.46) had shown significantly greater efficacy for cessation of EScompared with ACTH low dose (LD). Similarly, for electroclinical response, dexamethasone (OR: 9.63; 95% CI: 1.99, 46.70) and prednisolone HD (OR: 3.46; 95% CI: 1.38, 8.68) had greater efficacy compared with ACTH LD. Safety outcomes revealed that hypertension was significantly less common with ACTH LD and prednisolone HD as compared with ACTH HD. This study provides quality evidence on preferred first-choice hormonal therapy for managing IESS in South Asia. ACTH HD, dexamethasone, and prednisolone HD are the most effective hormonal therapy options with dose-dependent therapeutic efficacy. PLAIN LANGUAGE SUMMARY: This study provides insights into the selection of first-line hormonal therapies among the various treatments for managing infantile epileptic spasms syndrome (IESS) in South Asia. The study findings suggested that the effectiveness of these therapies is dose-dependent, with high doses of ACTH, dexamethasone, and prednisolone being the most effective for achieving cessation of epileptic spasms.

Human quad liver-on-chip system as a tool toward bridging the gap between animals and humans regarding toxicology and pharmacology of a cannabidiol-rich cannabis extract

Cannabidiol (CBD) is a major phytocannabinoid from Cannabis sativa. It is currently widely available and widely used in the USA, but despite its rapid progress to market, the pharmacology and toxicology of both CBD and cannabidiol-rich cannabis extracts (CRCE) remain largely unknown. The goals of this study were to investigate the potential of a novel human microphysiological system to emulate CRCE-induced hepatotoxicity and pharmacological properties demonstrated in animal models. For this purpose, C57BL6/J male mice were subjected to dosing with either 0, 61.5, 184.5, or 615 mg/kg of CRCE for 10 days. The liver-on-chip system, incorporating human primary hepatocytes, sinusoidal endothelial cells, as well as Kupffer and stellate cells was subjected to 0, 300, 1,200, or 4,400 ng/mL of CRCE (8 h exposure followed by 16 h washout) for 5 days. Administration of CRCE in mice resulted in nearly 4-fold elevations of plasma ALT at 615 mg/kg (p < 0.01) and a dose-dependent decrease in intrahepatic miR-122. Elevated levels of ALT, paralleled by decreased intrahepatic and increased effluent levels of miR-122, were also observed in the liver-on-chip, although these results were not statistically significant. Exposure to CRCE resulted in a robust and dose-dependent induction of key cytochrome P450 enzymes, namely Cyp1a2, Cyp2b6 (CYP2B10), Cyp2e1, and Cyp2c9 (CYP2C19) in both mouse livers and liver-on-chip. The results of this study demonstrate the congruence between the responses observed in mouse and human liver-on-chip experimental systems and provide evidence of the potential microphysiological systems hold for translating animal data into clinical practice.

CBD in the Treatment of Epilepsy

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.

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.

Factors associated with long-term benzodiazepine and Z-drug use across the lifespan and 5-year temporal trajectories among incident users: a Swedish nationwide register-based study

PURPOSE

Despite being discouraged by guidelines, long-term use of benzodiazepines and related Z-drugs (BZDR) remains frequent in the real-world. An improved understanding of factors associated with the transition from new to long-term BZDR use and of temporal BZDR use trajectories is needed. We aimed to assess the proportion of long-term BZDR use (> 6 months) in incident BZDR-recipients across the lifespan; identify 5-year BZDR use trajectories; and explore individual characteristics (demographic, socioeconomic and clinical) and prescribing-related factors (pharmacological properties of the initial BZDR, prescriber's healthcare level, and concurrent dispensing of other medications) associated with long-term BZDR use and distinct trajectories.

METHODS

Our nationwide register-based cohort included all BZDR-recipients in Sweden with first dispensation in 2007-2013. Trajectories of BZDR use days per year were built using group-based trajectory modelling. Cox regression and multinomial logistic regression were fitted to assess the predictors of long-term BZDR use and trajectories' membership.

RESULTS

In 930,465 incident BZDR-recipients, long-term use increased with age (20.7%, 41.0%, and 57.4% in 0-17, 18-64, and ≥ 65-year-olds, respectively). Four BZDR use trajectories emerged, labelled 'discontinued', 'decreasing', 'slow decreasing' and 'maintained'. The proportion of the 'discontinued' trajectory members was the largest in all ages, but reduced from 75.0% in the youths to 39.3% in the elderly, whereas the 'maintained' increased with age from 4.6% to 36.7%. Prescribing-related factors, in particular multiple BZDRs at initiation and concurrent dispensing of other medications, were associated with increased risks of long-term (vs short-term) BZDR use and developing other trajectories (vs 'discontinued') in all age groups.

CONCLUSIONS

The findings highlight the importance of raising awareness and providing support to prescribers to make evidence-based decisions on initiating and monitoring BZDR treatment across the lifespan.

Current and emerging pharmacotherapy for the treatment of Lennox-Gastaut syndrome

INTRODUCTION

Lennox-Gastaut syndrome (LGS) is a severe childhood-onset epileptic encephalopathy, characterized by multiple seizure types, generalized slow spike-and-wave complexes in the EEG, and cognitive impairment. Seizures in LGS are typically resistant to treatment with antiseizure medications (ASMs). Tonic/atonic ('drop') seizures are of particular concern, due to their liability to cause physical injury.

AREAS COVERED

We summarize evidence for current and emerging ASMs for the treatment of seizures in LGS. The review focuses on findings from randomized, double-blind, placebo-controlled trials (RDBCTs). For ASMs for which no double-blind trials were identified, lower quality evidence was considered. Novel pharmacological agents currently undergoing investigation for the treatment of LGS are also briefly discussed.

EXPERT OPINION

Evidence from RDBCTs supports the use of cannabidiol, clobazam, felbamate, fenfluramine, lamotrigine, rufinamide, and topiramate as adjunct treatments for drop seizures. Percentage decreases in drop seizure frequency ranged from 68.3% with high-dose clobazam to 14.8% with topiramate. Valproate continues to be considered the first-line treatment, despite the absence of RDBCTs specifically in LGS. Most individuals with LGS will require treatment with multiple ASMs. Treatment decisions should be individualized and take into account adverse effects, comorbidities, general quality of life, and drug interactions, as well as individual efficacy.

Efficacy and Safety of Dietary Therapies for Childhood Drug-Resistant Epilepsy: A Systematic Review and Network Meta-analysis

Importance

Despite advances in the understanding of dietary therapies in children with drug-resistant epilepsy, no quantitative comparison exists between different dietary interventions.

Objective

To evaluate the comparative efficacy and safety of various dietary therapies in childhood drug-resistant epilepsy.

Data Sources

Systematic review and network meta-analysis (frequentist) of studies in PubMed, Embase, Cochrane, and Ovid published from inception to April 2022 using the search terms ketogenic diet, medium chain triglyceride diet, modified Atkins diet, low glycemic index therapy, and refractory epilepsy.

Study Selection

Randomized clinical trials comparing different dietary therapies (ketogenic diet, modified Atkins diet, and low glycemic index therapy) with each other or care as usual in childhood drug-resistant epilepsy were included. Abstract, title, and full text were screened independently by 2 reviewers.

Data Extraction and Synthesis

Data extraction was conducted following Preferred Reporting Items for Systematic Reviews and Meta-analyses reporting guideline. Cochrane risk-of-bias tool was used to assess the study quality. Effect sizes were calculated as odds ratio with 95% CI using random-effects model. The hierarchy of competing interventions was defined using the surface under the cumulative ranking curve.

Main Outcomes and Measures

Short-term (≤3 months) 50% or higher and 90% or higher reduction in seizure frequency and treatment withdrawal due to adverse events were the primary efficacy and safety outcomes.

Results

Of 2158 citations, 12 randomized clinical trials (907 patients) qualified for inclusion. In the short term, all dietary interventions were more efficacious than care as usual for 50% or higher seizure reduction (low glycemic index therapy: odds ratio [OR], 24.7 [95% CI, 5.3-115.4]; modified Atkins diet: OR, 11.3 [95% CI, 5.1-25.1]; ketogenic diet: OR, 8.6 [95% CI, 3.7-20.0]), while ketogenic diet (OR, 6.5 [95% CI, 2.3-18.0]) and modified Atkins diet (OR, 5.1 [95% CI, 2.2-12.0]) were better than care as usual for seizure reduction of 90% or higher. However, adverse event-related discontinuation rates were significantly higher for ketogenic diet (OR, 8.6 [95% CI, 1.8-40.6]) and modified Atkins diet (OR, 6.5 [95% CI, 1.4-31.2]) compared with care as usual. Indirectly, there was no significant difference between dietary therapies in efficacy and safety outcomes.

Conclusions and Relevance

This study found that all dietary therapies are effective in the short term. However, modified Atkins diet had better tolerability, higher probability for 50% or higher seizure reduction, and comparable probability for 90% or higher seizure reduction and may be a sounder option than ketogenic diet. Direct head-to-head comparison studies are needed to confirm these findings.