Rescue therapies for seizure emergencies: current and future landscape

Outpatient management of prolonged seizures and seizure clusters to prevent progression to a higher-level emergency: Consensus recommendations of an expert working group

OBJECTIVE

The management of prolonged seizures (PS) and seizure clusters (SC) is impeded by the lack of international, evidence-based guidance. We aimed to develop expert recommendations regarding consensus definitions of PS, SC, and treatment goals to prevent progression to higher-level emergencies such as status epilepticus (SE).

METHODS

An expert working group, comprising 12 epileptologists, neurologists, and pharmacologists from Europe and North America, used a modified Delphi consensus methodology to develop and anonymously vote on statements. Consensus was defined as ≥75% voting "Agree"/"Strongly agree."

RESULTS

All group members strongly agreed that termination of an ongoing seizure in as short a time as possible is the primary goal of rapid and early seizure termination (REST) and that an ideal medication for REST would start to act within 2 min of administration to terminate ongoing seizure activity. Consensus was reached on the terminology defining PS (with proposed thresholds of 5 min for prolonged focal seizures and 2 min for prolonged absence seizures and the convulsive phase of bilateral tonic-clonic seizures) and SC (an abnormal increase in seizure frequency compared with the individual patient's usual seizure pattern). All group members strongly agreed or agreed that patients who have experienced a PS should be offered a REST medication, and all patients who have experienced a SC should be offered an acute cluster treatment (ACT). Further, when prescribing a REST medication or ACT, a seizure action plan should be agreed upon in consultation with the patient and caregiver.

SIGNIFICANCE

The expert working group had a high level of agreement on the recommendations for defining and managing PS and SC. These recommendations will complement the existing guidance for the management of acute seizures, with the possibility of treating them earlier to potentially avoid progression to more severe seizures, including SE.

Identification of a novel KCNT2 variant in a family with developmental and epileptic encephalopathies: a case report and literature review

Background: Developmental and epileptic encephalopathies (DEEs) are a group of heterogeneous neurodevelopmental diseases characterized mainly by developmental delay/intellectual disability and early-onset epilepsy. Researchers have identified variations in the KCNT2 gene (OMIM* 610044) as the cause of DEE type 57 (MIM# 617771). Case presentation: We report in this study a 46-year-old woman who presented with early-onset epilepsy, intellectual disability, hypertrichosis, coarse facial features, and short stature. Besides, there were four other affected individuals in her family history, including two elder brothers, a younger brother, and their mother. We collected blood samples from the proband, her two affected brothers, and her clinically normal daughter for genetic analysis. Clinical exome sequencing revealed a novel heterozygous variant in the KCNT2 gene (NM_198503: c.188G>A, p.Arg63His) in the proband and her two affected brothers, while her daughter did not carry this variant. Furthermore, we reviewed all 25 patients identified in the literature with KCNT2 variants and compared their phenotypes. Conclusion: Epilepsy and intellectual disability/developmental delay occur in almost all patients with KCNT2 variants. KCNT2-relevant DEEs partially overlap with the clinical phenotypes of KATP channel diseases, particularly in hypertrichosis and distinctive coarse facial features.

Benzodiazepines for the Treatment of Seizure Clusters

Patients with epilepsy may experience seizure clusters, which are described by the US Food and Drug Administration (FDA) as intermittent, stereotypic episodes of frequent seizure activity that are distinct from a patient's usual seizure pattern. Untreated seizure clusters may increase the risk for status epilepticus, as well as decrease quality of life and increase burden on patients and care partners. Benzodiazepine therapies are the mainstay for acute treatment of seizure clusters and are often administered by nonmedical care partners outside a healthcare facility. Three rescue therapies are currently FDA-approved for this indication, with diazepam rectal gel being the first in 1997, for patients aged ≥  2 years. Limitations of rectal administration (e.g., positioning and disrobing the patient, which may affect ease of use and social acceptability; interpatient variation in bioavailability) led to the investigation of the potential for nasal administration as an alternative. Midazolam nasal spray (MDS) was approved by the FDA in 2019 for patients aged ≥  12 years and diazepam nasal spray (DNS) in 2020 for patients aged ≥  6 years; these two intranasal therapies have differences in their formulations [e.g., organic solvents (MDS) vs. Intravail and vitamin E for absorption and solubility (DNS)], effectiveness (e.g., proportion of seizure clusters requiring only one dose), and safety profiles. In clinical studies, the proportion of seizure clusters for which only one dose of medication was used varied between the three approved rescue therapies with the highest single-dose rate for any time period for DNS; however, although studies for all three preparations enrolled patients with highly intractable epilepsy, inclusion and exclusion criteria varied, so the three cannot be directly compared. Treatments that have been used off-label for seizure clusters in the USA include midazolam for injection as an intranasal spray (indicated for sedation/anxiolysis/amnesia and anesthesia) and tablet forms of clonazepam (indicated for treatment for seizure disorders) and lorazepam (indicated for anxiety). In the European Union, buccal and intranasal midazolam are used for treating the indication of prolonged, acute convulsive seizures and rectal diazepam solution for the indication of epileptic and febrile convulsions; duration of effectiveness for these medications for the treatment of seizure clusters has not been established. This paper examines the literature context for understanding seizure clusters and their treatment and provides effectiveness, safety, and administration details for the three FDA-approved rescue therapies. Additionally, other medications that are used for rescue therapy in the USA and globally are discussed. Finally, the potential benefits of seizure action plans and candidates for their use are addressed. This paper is intended to provide details about the unique characteristics of rescue therapies for seizure clusters to help clarify appropriate treatment for individual patients.

Opportunities for Community Pharmacists to Counsel Patients With Epilepsy and Seizure Clusters to Overcome Barriers and Foster Appropriate Treatment

Some patients with epilepsy experience seizure clusters, which may be defined as 2 or more seizures occurring within 24 hours. Left untreated, seizure clusters increase the risk for physical injury and may progress to status epilepticus, irreversible neurologic injury, and death. Rescue therapy is based on benzodiazepine treatment. Prompt, appropriate use should be specified in patients' individualized seizure action plans. Most seizure clusters occur outside the hospital setting. The ideal rescue therapy allows for easy and quick administration by a nonmedical person, which may minimize the need for intervention by emergency medical personnel or transportation to the hospital. In the 2 decades before the approval of 2 intranasal benzodiazepines in 2019 and 2020, rectal diazepam was the only route of administration approved by the US Food and Drug Administration specifically for seizure clusters. Each of the approved intranasal formulations has a unique profile. Both offer a convenient and socially acceptable route of administration. Recognition of seizure clusters and timing of proper administration are key to successful use of rescue therapy. Pharmacists' counseling plays an important role in reinforcing when and how to appropriately administer rescue therapies and the importance of consistently using rescue treatment when indicated to promote effective management. This review includes resources for pharmacists, patients, and caregivers; reviews currently available treatments; and discusses seizure action plans that support effective treatment of seizure clusters.

A retrospective multicentric study on the effectiveness of intravenous brivaracetam in seizure clusters: Data from the Italian experience

OBJECTIVE

Nearly half of people with epilepsy (PWE) are expected to develop seizure clusters (SC), with the subsequent risk of hospitalization. The aim of the present study was to evaluate the use, effectiveness and safety of intravenous (IV) brivaracetam (BRV) in the treatment of SC.

METHODS

Retrospective multicentric study of patients with SC (≥ 2 seizures/24 h) who received IV BRV. Data collection occurred from January 2019 to April 2022 in 25 Italian neurology units. Primary efficacy outcome was seizure freedom up to 24 h from BRV administration. We also evaluated the risk of evolution into Status Epilepticus (SE) at 6, 12 and 24 h after treatment initiation. A Cox regression model was used to identify outcome predictors.

RESULTS

97 patients were included (mean age 62 years), 74 (76%) of whom had a history of epilepsy (with drug resistant seizures in 49% of cases). BRV was administered as first line treatment in 16% of the episodes, while it was used as first or second drug after benzodiazepines failure in 49% and 35% of episodes, respectively. On the one hand, 58% patients were seizure free at 24 h after BRV administration and no other rescue medications were used in 75 out of 97 cases (77%) On the other hand, SC evolved into SE in 17% of cases. A higher probability of seizure relapse and/or evolution into SE was observed in patients without a prior history of epilepsy (HR 2.0; 95% CI 1.03 - 4.1) and in case of BRV administration as second/third line drug (HR 3.2; 95% CI 1.1 - 9.7). No severe treatment emergent adverse events were observed.

SIGNIFICANCE

In our cohort, IV BRV resulted to be well tolerated for the treatment of SC and it could be considered as a treatment option, particularly in case of in-hospital onset. However, the underlying etiology seems to be the main outcome predictor.

Translational Considerations in the Development of Intranasal Treatments for Epilepsy

Epilepsy is a common and serious neurological disorder, to which a high proportion of patients continue to be considered "drug-resistant", despite the availability of a host of anti-seizure drugs. Investigation into new treatment strategies is therefore of great importance. One such strategy is the use of the nose to deliver drugs directly to the brain with the help of pharmaceutical formulation to overcome the physical challenges presented by this route. The following review explores intranasal delivery of anti-seizure drugs, covering the link between the nose and seizures, pathways from the nose to the brain, current formulations in clinical use, animal seizure models and their proposed application in studying intranasal treatments, and a critical discussion of relevant pre-clinical studies in the literature.

Introduction to use of an acute seizure action plan for seizure clusters and guidance for implementation

It is important for patients with epilepsy and their caregivers, including care partners, to understand the patient's seizure clusters and what to do when they occur. In many instances, seizure clusters are unique to each patient. The knowledge gained from understanding a patient's seizure cluster or seizure pattern provides a foundation for taking prompt action to prevent worsening to prolonged seizures, status epilepticus, and potentially death. Seizure action plans (SAPs), which are similar to the disease-related treatment action plans for other conditions, can be developed by a health care provider (HCP) in conjunction with the patient with epilepsy and/or caregivers, and SAPs are specifically customized for the individual patient and his or her seizure management. However, the current literature lacks unified guidance on how to design SAPs that will help prepare patients and caregivers for rapidly determining and initiating appropriate treatment of acute seizure emergencies in the community and at home. Here, we examine the current usage and value of SAPs for pediatric and adult patients with epilepsy, and we introduce the concept of the acute SAP (ASAP) for use specifically during seizure emergencies, such as seizure clusters. This type of standardized, simplified, and customized plan can rapidly and concisely provide patients and caregivers with a practical protocol to treat a seizure cluster consistently, appropriately, and in a timely manner. Details on potential content and formats of ASAPs are provided. Following this is a discussion of barriers to ASAP use that may affect HCPs or patients and caregivers, including lack of standardization, relevance, and personalization and pitfalls associated with technology. This leads into a discussion of guidance for developing, implementing, and updating ASAPs that suggests ways to address the barriers and ensure that the ASAP is best suited to the patient's needs.

Pharmacotherapeutic management of seizures in patients with Angleman syndrome

Approximately 80-90% of patients with Angelman syndrome (AS) develop childhood-onset intractable seizures with major negative impact on the quality of life.Thus adequate management of seizures is the most critical priority to improve health-related quality of life in children with AS.

AREAS COVERED

The primary focus of the review is on pharmacotherapeutic management of seizures. The first part of the review briefly discusses epileptogenesis and polymorphic seizure phenotypes associated with AS to understand pharmacotherapeutic decision-making better. Next, the review explores individual antiseizure medicines (ASMs) and their potential therapeutic utility. Lastly, some future and emerging treatment options are discussed that can transform the management of seizures in patients with AS.

EXPERT OPINION

Evidence for treating seizures in AS mainly derives from low-quality studies. Levetiracetam and clobazam are the most commonly used ASMs. Although the potential utility of several other ASMs(valproate, topiramate, lamotrigine, ethosuximide, clonazepam) has been well documented for some time, the treatment landscape may rapidly evolve due to the availability of newer and better tolerated ASMs(cannabidiol oil, brivaracetam, perampanel). In addition, a better understanding of the underlying pathogenesis and the development of molecular therapeutics offer hope for precision therapies for seizures.