Monotherapy or Polytherapy for First-Line Treatment of SE?

Efficacy of Low-Dose Ketamine and Propofol in the Treatment of Experimental Refractory Status Epilepticus on Male Rats

Refractory status epilepticus (RSE) is a condition with serious mortality and morbidity rate, resistant to benzodiazepine and second-line antiepileptic drugs. This study aimed to electrophysiologically investigate the combination of NMDA receptor antagonist ketamine and GABAergic agent propofol in an RSE model induced by lithium-pilocarpine in male Sprague-Dawley rats. Seventy-two male Sprague-Dawley rats were divided into nine groups. The RSE model was induced by subcutaneous injection of lithium-CI (5 mEq/kg) and intraperitoneal injection of pilocarpine-HCl (320 mg/kg), after implanting tripolar EEG electrode. Ketamine (30, 60, and 90 mg/kg), propofol (20, 40, and 80 mg/kg), and combinations of both drugs (15 + 20 and 30 + 40 mg/kg) were administered intraperitoneally to animals with RSE. Video-EEG recordings were taken after inducing model and 48 h later. The efficacy of drugs was statistically evaluated based on spike frequencies (spikes/min) and amplitudes (mV). Compared to RSE group, it was determined that 30 and 60 mg/kg doses of ketamine provided effective seizure control and prevented mortality (p < 0.001), while the 90 mg/kg showed toxic effects in all animals and caused mortality. The 80 mg/kg dose of propofol provided seizure control and reduced the mortality rate to 16.7% (p < 0.001), whereas the 20 mg/kg resulted in a 100% mortality rate. The low-dose ketamine+propofol (15 + 20 mg/kg) combination provided early onset seizure control and were as effective as 80 mg/kg propofol (p < 0.05). The study concluded that in the experimental RSE model, seizure control could be achieved with low-dose combination of ketamine and propofol without the need for high doses as in monotherapy, thus preventing dose-related adverse effects.

Levetiracetam and Midazolam vs Midazolam Alone for First-Line Treatment of Children With Generalized Convulsive Status Epilepticus (Lev-Mid Study): A Randomized Controlled Trial

BACKGROUND

Benzodiazepines are the first-line anti-seizure medication (ASM) for generalized convulsive status epilepticus (GCSE), but they fail to end seizures in a third of cases. Combining benzodiazepines with another ASM that acts by a different pathway could be a potential strategy for rapid control of GCSE.

OBJECTIVES

To evaluate the efficacy of adding levetiracetam to midazolam in the initial treatment of pediatric GCSE.

DESIGN

Double-blind randomized controlled trial.

SETTING

Pediatric emergency room at Sohag University Hospital between June, 2021 and August, 2022.

PARTICIPANTS

Children aged between 1 month and 16 years with GCSE lasting more than 5 min.

INTERVENTIONS

Intravenous levetiracetam (60 mg/kg over 5 min) and midazolam (Lev-Mid group) or placebo and midazolam (Pla-Mid group) as first-line anticonvulsive therapy.

OUTCOME MEASURES

Primary: cessation of clinical seizures at 20-min study time point. Secondary: cessation of clinical seizures at 40-min study time point, need for a second midazolam dose, seizure control at 24-hr, need for intubation, and adverse effects.

RESULTS

Cessation of clinical seizures at 20-min occurred in 55 children (76%) in Lev-Mid group compared with 50 (69%) in the Pla-Mid group [RR (95% CI) 1.1 (0.9-1.34); P=0.35]. No significant difference was found between the two groups regarding the need for a second midazolam dose [44.4% vs 55.6%; RR (95% CI) 0.8 (0.58-1.11); P=0.18] as well as cessation of clinical seizures at 40-min [96% vs 92%; RR (95% CI)1.05 (0.96-1.14); P=0.49] and seizure control at 24-hr [85% vs 76%; RR (95% CI) 1.12 (0.94-1.3); P=0.21]. Intubation was required for three patients in the Lev-Mid group and six patients in the Pla-Mid group [RR (95%CI) 0.5 (0.13- 1.92); P=0.49]. No other adverse effects or mortality were observed during the 24-hour study timeframe.

CONCLUSION

Combined levetiracetam and midazolam for initial management of pediatric GCSE presents no significant advantage over midazolam alone in cessation of clinical seizures at 20-min.

Insight into Drug Resistance in Status Epilepticus: Evidence from Animal Models

Status epilepticus (SE), a condition with abnormally prolonged seizures, is a severe type of epilepsy. At present, SE is not well controlled by clinical treatments. Antiepileptic drugs (AEDs) are the main therapeutic approaches, but they are effective for SE only with a narrow intervening window, and they easily induce resistance. Thus, in this review, we provide an updated summary for an insight into drug-resistant SE, hoping to add to the understanding of the mechanism of refractory SE and the development of active compounds. Firstly, we briefly outline the limitations of current drug treatments for SE by summarizing the extensive experimental literature and clinical data through a search of the PubMed database, and then summarize the common animal models of refractory SE with their advantages and disadvantages. Notably, we also briefly review some of the hypotheses about drug resistance in SE that are well accepted in the field, and furthermore, put forward future perspectives for follow-up research on SE.

Status Epilepticus-Work-Up and Management in Children

Status epilepticus (SE) is one of the most common neurological emergencies in children and has a mortality of 2 to 4%. Admissions for SE are very resource-consuming, especially in refractory and super-refractory SE. An increasing understanding of the pathophysiology of SE leaves room for improving SE treatment protocols, including medication choice and timing. Selecting the most efficacious medications and giving them in a timely manner may improve outcomes. Benzodiazepines are commonly used as first line and they can be used in the prehospital setting, where most SE episodes begin. The diagnostic work-up should start simultaneously to initial treatment, or as soon as possible, to detect potentially treatable causes of SE. Although most etiologies are recognized after the first evaluation, the detection of more unusual causes may become challenging in selected cases. SE is a life-threatening medical emergency in which prompt and efficacious treatment may improve outcomes. We provide a summary of existing evidence to guide clinical decisions regarding the work-up and treatment of SE in pediatric patients.

Recommandations Formalisées d’Experts SRLF/SFMU : Prise en charge des états de mal épileptiques en préhospitalier, en structure d’urgence et en réanimation dans les 48 premières heures (A l’exclusion du nouveau-né et du nourrisson)

La Société de réanimation de langue française et la Société française de médecine d’urgence ont décidé d’élaborer de nouvelles recommandations sur la prise en charge de l’état mal épileptique (EME) avec l’ambition de répondre le plus possible aux nombreuses questions pratiques que soulèvent les EME : diagnostic, enquête étiologique, traitement non spécifique et spécifique. Vingt-cinq experts ont analysé la littérature scientifique et formulé des recommandations selon la méthodologie GRADE. Les experts se sont accordés sur 96 recommandations. Les recommandations avec le niveau de preuve le plus fort ne concernent que l’EME tonico-clonique généralisé (EMTCG) : l’usage des benzodiazépines en première ligne (clonazépam en intraveineux direct ou midazolam en intramusculaire) est recommandé, répété 5 min après la première injection (à l’exception du midazolam) en cas de persistance clinique. En cas de persistance 5 min après cette seconde injection, il est proposé d’administrer la seconde ligne thérapeutique : valproate de sodium, (fos-)phénytoïne, phénobarbital ou lévétiracétam. La persistance avérée de convulsions 30 min après le début de l’administration du traitement de deuxième ligne signe l’EMETCG réfractaire. Il est alors proposé de recourir à un coma thérapeutique au moyen d’un agent anesthésique intraveineux de type midazolam ou propofol. Des recommandations spécifiques à l’enfant et aux autres EME sont aussi énoncées.

Pharmacotherapy for Pediatric Convulsive Status Epilepticus

Convulsive status epilepticus (CSE) is one of the most common pediatric neurological emergencies. Ongoing seizure activity is a dynamic process and may be associated with progressive impairment of gamma-aminobutyric acid (GABA)-mediated inhibition due to rapid internalization of GABA_A receptors. Further hyperexcitability may be caused by AMPA (alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid) and NMDA (N-methyl-D-aspartic acid) receptors moving from subsynaptic sites to the synaptic membrane. Receptor trafficking during prolonged seizures may contribute to difficulties treating seizures of longer duration and may provide some of the pathophysiological underpinnings of established and refractory SE (RSE). Simultaneously, a practice change toward more rapid initiation of first-line benzodiazepine (BZD) treatment and faster escalation to second-line non-BZD treatment for established SE is in progress. Early administration of the recommended BZD dose is suggested. For second-line treatment, non-BZD anti-seizure medications (ASMs) include valproate, fosphenytoin, or levetiracetam, among others, and at this point there is no clear evidence that any one of these options is better than the others. If seizures continue after second-line ASMs, RSE is manifested. RSE treatment consists of bolus doses and titration of continuous infusions under continuous electro-encephalography (EEG) guidance until electrographic seizure cessation or burst-suppression. Ultimately, etiological workup and related treatment of CSE, including broad spectrum immunotherapies as clinically indicated, is crucial. A potential therapeutic approach for future studies may entail consideration of interventions that may accelerate diagnosis and treatment of SE, as well as rational and early polytherapy based on synergism between ASMs by utilizing medications targeting different mechanisms of epileptogenesis and epileptogenicity.

Open-label clinical trial of rectally administered levetiracetam as supplemental treatment in dogs with cluster seizures

Background

Treatment options for at‐home management of cluster seizures (CS) and status epilepticus (SE) are limited. The pharmacokinetics of levetiracetam (LEV) after rectal administration in both healthy and epileptic dogs has been investigated recently.

Hypothesis/Objectives

To investigate the clinical efficacy of rectally administered LEV in preventing additional seizures in dogs presented for CS and SE. We hypothesized that rectal administration of LEV in addition to a standard treatment protocol would provide better control of seizure activity as compared with the standard treatment protocol alone.

Animals

Fifty‐seven client‐owned dogs with CS or SE.

Methods

Prospective open‐label clinical trial. Patients included in the study were assigned to receive either a standard treatment protocol comprising IV/rectal diazepam and IV phenobarbital q8h (control group) or a standard treatment protocol in association with a single dose of 40 mg/kg LEV rectally (rectal LEV group). Dogs that experienced no additional seizures were defined as responders, whereas those that showed additional seizure activity were classified as nonresponders.

Results

Twenty‐one dogs were assigned to the rectal LEV group, and 36 to control group. Given the small number of cases of SE, statistical analysis was performed only on patients with CS. The response rate was 94% in the rectal LEV group and 48% in the control group (P < .001).

Conclusions and Clinical Importance

Rectally administered LEV combined with a standard treatment protocol provided good control of seizure activity in patients with CS. The validity of these results should be confirmed in a double‐blinded, placebo‐controlled clinical trial.

Novel drugs and early polypharmacotherapy in status epilepticus

PURPOSE

Rescue medications for status epilepticus (SE) have a relatively high rate of failure. The purpose of this review is to summarize the evidence for the efficacy of novel drugs and early polypharmacotherapy for SE.

METHOD

Literature review.

RESULTS

New drugs and treatment strategies aim to target the pathophysiology of SE in order to improve seizure control and outcomes. Changes at the synapse level during SE include a progressive decrease in synaptic GABA_A receptors and increase in synaptic NMDA receptors. These changes tend to promote self-sustaining seizures. Current SE guidelines recommend a rapid stepwise treatment using benzodiazepines in monotherapy as the first-line treatment, targeting GABA_A synaptic receptors. Novel treatment approaches target GABA_A synaptic and extrasynaptic receptors with allopregnanolone, and NMDA receptors with ketamine. Novel rescue treatments used for SE include topiramate, brivaracetam, and perampanel, which are already marketed in epilepsy. Some available drugs not marketed for use in epilepsy have been used in the treatment of SE, and other agents are being studied for this purpose. Early polytherapy, most frequently combining a benzodiazepine with a second-line drug or an NMDA receptor antagonist, might potentially increase seizure control with relatively minor increase in side effects. Although many preclinical studies support novel drugs and early polytherapy in SE, human studies are scarce and inconclusive. Currently, evidence is lacking to recommend specific combinations of these new agents.

CONCLUSIONS

Novel drugs and strategies target the underlying pathophysiology of SE with the intent to improve seizure control and outcomes.

Pathophysiology of convulsive status epilepticus

PURPOSE

To summarize the pathophysiology of convulsive status epilepticus (SE) with a focus on practical implications for treatment.

METHOD

Narrative review of the medical literature on the pathophysiology of convulsive SE. We considered both animal models of SE and clinical studies.

RESULTS

Convulsive SE is an emergency in which prolonged convulsive seizures are associated with cardiorespiratory instability, hypoxia, hypoglycemia, and hyperthermia. Supportive treatment helps correct these physiological imbalances. When treatment is delayed, the ability of first line seizure suppressing medications to terminate the seizure can be reduced. Animal studies have suggested that GABA_A receptor trafficking may contribute to the failure of the first line therapies and that NMDA receptor antagonists such as ketamine may become more effective as seizures last longer. Potential strategies to take advantage of these changes in pathophysiology include a rapid escalation from benzodiazepines to non-benzodiazepine antiepileptic drugs (AEDs), early polytherapy and use of NMDA antagonists such as ketamine for refractory convulsive SE. Despite the importance of a timely treatment of convulsive SE, major treatment delays are frequent in clinical practice. Policies to improve time to treatment, especially in convulsive SE that starts outside the hospital, may improve response to treatment and convulsive SE outcomes.

CONCLUSIONS

Convulsive SE is a time-sensitive emergency in which the underlying pathophysiology may provide targets for improving treatment strategies. A timely transition from benzodiazepines to other AEDs may help reduce treatment resistance in convulsive SE.

Antiepileptic Drugs and Liver Disease

Acute, symptomatic seizures or epilepsy may complicate the course of hepatic disease. Choosing the most appropriate antiepileptic drug in this setting represents a difficult challenge, as most medications are metabolized by the liver. This article focuses on the acute and chronic treatment of seizures in patients with advanced liver disease and reviews the hepatotoxic potential of specific antiepileptic drugs. Newer antiepileptic drugs without, or with minimal, hepatic metabolism, such as levetiracetam, lacosamide, topiramate, gabapentin, and pregabalin should be used as first-line therapy. Medications undergoing extensive hepatic metabolism, such as valproic acid, phenytoin, and felbamate should be used as drugs of last resort. In special circumstances, as in patients affected by acute intermittent porphyria, exposure to most antiepileptic drugs could precipitate attacks. In this clinical scenario, bromides, levetiracetam, gabapentin, and vigabatrin constitute safe choices. For the treatment of status epilepticus, levetiracetam and lacosamide, available in intravenous preparations, are good second-line therapies after benzodiazepines fail to control seizures. Hepatotoxicity is also a rare and unexpected side effect of some antiepileptic drugs. Drugs such as valproic acid, phenytoin, and felbamate, have a well-recognized association with liver toxicity. Other antiepileptic drugs, including phenobarbital, benzodiazepines, ethosuximide, and the newer generations of antiepileptic drugs, have only rarely been linked to hepatotoxicity. Thus physicians should be mindful of the pharmacokinetic profile and the hepatotoxic potential of the different antiepileptic drugs available to treat patients affected by liver disease.

[Not Available]

Zusammenfassung. Der Status epilepticus, vor allem der konvulsive tonisch-klonische (Grand mal) Status epilepticus, ist ein Notfall, der zu einer sofortigen Behandlung führen muss. Die frühe Behandlung ist effektiver als der spätere Beginn, ebenso wie der Einsatz standardisierter Therapieprotokolle. Nach der Gabe von Benzodiazepinen muss die Aufdosierung eines Antikonvulsivums (Levetiracetam, Valproat oder Phenytoin) erfolgen, um das Wiederauftreten von Anfällen zu verhindern. Beim refraktären Status epilepticus werden die Anästhetika Propofol oder Midazolam (oder Thiopental) vorzugsweise unter EEG-Ableitung mit einem Burst-Suppressions-Muster eingesetzt. Neben der raschen Therapie sollte die Diagnostik nach der Ursache des Status epilepticus nicht vergessen werden. Insbesondere bei Persistenz sollte immer auch die Überprüfung der Diagnose erfolgen, um das Vorliegen eines Pseudostatus nicht-epileptischer Anfälle nicht zu übersehen.