Medical management of status epilepticus: Emergency room to intensive care unit

Relative Bioavailability Study of Midazolam Intramuscularly Administered with the Needle-Free Auto-Injector ZENEO® in Healthy Adults

INTRODUCTION

Intramuscular (IM) midazolam is indicated for the treatment of status epilepticus. Administration must be efficient to rapidly terminate prolonged seizures and prevent complications. The objective of this study was to compare, in terms of relative bioavailability and bioequivalence, IM midazolam injection by needle-free auto-injector, in different settings, to IM midazolam injection by a conventional syringe and needle.

METHODS

In this open-label, randomized, four-period crossover study, healthy adults received single doses of midazolam (10 mg) under fasting conditions. The reference treatment (conventional syringe) was administered once, on bare skin in the thigh. The tested treatment (the needle-free auto-injector ZENEO®) was administered three times: on bare skin in the thigh, on bare skin in the ventrogluteal area, and through clothing in the thigh. Repeated plasma samples were collected to obtain 36-h pharmacokinetic (PK) profiles. Primary PK parameters were area under the plasma concentration-time curve, from time zero to the last measurable time point (AUC0-t) and from time zero to infinity (AUC0-∞), and the maximum observed plasma concentration (Cmax).

RESULTS

Forty adults were enrolled and included in the PK analysis set. In all comparisons, the 90% confidence interval (CI) of the least-squares geometric mean ratios for AUC0-t and AUC0-∞ were within the bioequivalence range of 80-125%, with low intra-individual coefficients of variation (< 20.5% for all parameters in all comparisons). Bioequivalence was also met for Cmax in all comparisons except when comparing the tested treatment through clothing versus the reference treatment, where the 90% CI lower limit was slightly outside the bioequivalence range (78.8%). With all tested treatments Cmax was slightly lower, but early mean plasma concentrations (first 10 min post-dosing) were higher when compared to the reference treatment. In general, all treatments were well tolerated, with maximum sedation 0.5-1 h post-injection.

DISCUSSION/CONCLUSION

This study establishes that IM midazolam injection on bare skin in the thigh with the ZENEO® is bioequivalent to IM midazolam injection with a syringe and needle. An acceptable relative bioavailability, compatible with emergency practice, was also shown in multiple settings. Higher mean concentrations within the first 10 min with the ZENEO® device, and quicker two-step injection suggest a faster onset of action, and thereby an earlier seizure termination, thus preventing the occurrence of prolonged seizure and neurological complications.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov identifier: NCT05026567. Registration first posted August 30, 2021, first patient enrolled May 9, 2022.

Management of Pediatric Convulsive Status Epilepticus From the Perspective of Emergency Nurses: A Cross-sectional, Multicenter Study

INTRODUCTION

Pediatric convulsive status epilepticus is one of the most common neurologic emergencies and should be managed by health care professionals as soon as possible based on current guidelines. This study aimed to determine the nursing approaches and management of pediatric convulsive status epilepticus from the perspective of emergency nurses in Turkey.

METHODS

A cross-sectional, multicenter study was conducted with 162 emergency nurses working in emergency departments in 35 different provinces in Turkey. The data were collected via an online form. Descriptive statistical methods were used in data analysis.

RESULTS

Most emergency nurses (72.2%) attempted an intravenous access immediately to administer antiseizure medications during the stabilization phase. Approximately half the emergency nurses stated that rectal diazePAM was frequently administered in the initial therapy phase and intravenous diazePAM was administered in the second therapy phase. The emergency nurses had most difficulties attempting intravenous access, determining status epilepticus types, and calming the parents.

DISCUSSION

As health care professionals and important members of the health team, emergency nurses have the responsibility to manage pediatric convulsive status epilepticus in the fastest and the most appropriate way based on current practice guidelines in emergency departments. When intravenous access is not available, nonintravenous benzodiazepines should be considered in the first-line treatment of pediatric convulsive status epilepticus, followed by immediate intravenous access.

Survey of Pediatric Status Epilepticus Treatment Practices and Adherence to Management Guidelines (Pedi-SPECTRUM e-Survey)

Aim

Survey of treatment practices and adherence to pediatric status epilepticus (PSE) management guidelines in India.

Methods

This eSurvey was conducted over 35 days (15th October to 20th November 2023) and included questions related to hospital setting; antiseizure medications (ASMs); ancillary treatment; facilities available; etiology; and adherence to PSE management guidelines.

Results

A total of 170 respondents participated, majority of them were working in tertiary level hospitals (94.1%) as pediatric intensivists (56.5%) and pediatricians (19.4%), and were in clinical practice for 2-10 years (46.5%). Majority use intravenous (IV) midazolam and levetiracetam as first- and second-line ASMs (67.1 and 51.2%, respectively). In cases with refractory status epilepticus (RSE), the most commonly used ASM is midazolam infusion (92.4%). For super-refractory status epilepticus (SRSE), the commonly used third-line ASMs include midazolam infusion (34.1%), thiopentone infusion (26.5%), high dose phenobarbitone (18.2%), and ketamine infusion (15.3%). Overall, in cases with SRSE, 44.7% respondents use ketamine infusion, 42.5% use add-on oral topiramate, and 34.7% use high-dose phenobarbitone (1-3 mg/kg/hour) infusion. Most respondents targeted both clinical and EEG seizure control (48.8%). Ancillary treatment used for SRSE included IV pyridoxine (57.1%), methylprednisolone (45.3%), IVIG (42.4%), ketogenic diet (40.6%), and second-line immunomodulation (33.5%). Most common causes were febrile SE, viral encephalitis, and febrile illness-related epilepsy syndrome (60.6%, 52.4%, and 37.1%, respectively). Facilities available included pediatric intensive care units (PICU) (97.1%), mechanical ventilation (98.2%), pediatric neurologist (68.8%), MRI brain (86.5%), EEG (69.4%), and viral PCR (58.2%). The compliance with guidelines for timing of initiation of ASM ranged from 63.5 to 88.8%.

Conclusion

Intravenous midazolam bolus/es, levetiracetam, and midazolam infusion are commonly used first-, second-, and third-line ASMs, respectively. There were wide variations in use of ASMs for RSE and SRSE, ancillary treatment, and compliance to PSE management guidelines.

How to cite this article

Suthar R, Angurana SK, Nallasamy K, Bansal A, Muralidharan J. Survey of Pediatric Status Epilepticus Treatment Practices and Adherence to Management Guidelines (Pedi-SPECTRUM e-Survey). Indian J Crit Care Med 2024;28(5):504-510.

Ketamine Efficacy for Management of Status Epilepticus: Considerations for Prehospital Clinicians

Current first-line therapies for seizure management recommend benzodiazepines, which target gamma-aminobutyric acid type A channels to stop the seizure activity. However, seizures may be refractory to traditional first-line therapies, transitioning into status epilepticus and becoming resistant to gamma-aminobutyric acid type A augmenting drugs. Although there are other antiseizure medications available for clinicians to use in the intensive care unit, these options can be less readily available outside of the intensive care unit and entirely absent in the prehospital setting. Instead, patients frequently receive multiple doses of first-line agents with increased risk of hemodynamic or airway collapse. Ketamine is readily available in the prehospital setting and emergency department, has well-established antiseizure effects with a favorable safety profile, and is a drug often used for several other indications. This article aimed to explore the utilization of ketamine for seizure management in the prehospital setting, reviewing seizure pathophysiology, established treatment mechanisms of action and pharmacokinetics, and potential benefits of early ketamine use in status epilepticus.

Antagonism of P2X7 receptors enhances lorazepam action in delaying seizure onset in an in vitro model of status epilepticus

Approximately 30% of patients with status epilepticus (SE) become refractory to two or more antiseizure medications (ASMs). There is thus a real need to identify novel targets against which to develop new ASMs for treating this clinical emergency. Among purinergic receptors, the ionotropic ATP-gated P2X7 receptor (P2X7R) has received attention as a potential ASM target. This study evaluated the effect of the selective P2X7R antagonist A740003 on acute seizures in the dentate gyrus (DG) of hippocampal brain slices, where P2X7Rs are highly expressed, with a view to establishing the potential of P2X7R antagonists as a therapy or adjunct with lorazepam (LZP) in refractory SE. Extracellular electrophysiological recordings were made from the DG of male mouse hippocampal slices. Spontaneous seizure-like events (SLEs) were induced by removing extracellular Mg2+ and sequentially adding the K+ channel blocker 4-aminopyridine and the adenosine A1 receptor antagonist 8-cyclopentyltheophylline, during which the early and late application of A740003 and/or lorazepam was evaluated. Our study revealed that, in the absence of changes in mRNA for P2X7Rs or inflammatory markers, P2X7R antagonism did not reduce the frequency of SLEs. However, A740003 in conjunction with LZP delayed the onset of seizures. Furthermore, our results support the need for employing LZP before seizures become refractory during SE as delayed application of LZP increased seizure frequency. These studies reveal possible sites of intervention that could have a positive impact in patients with high risk of suffering SE.

Trends and Differences in Status Epilepticus Treatment of Children and Adults Over 10 Years: A Comparative Study of Medical Records (2012-2021) from a University Hospital in Germany

BACKGROUND AND OBJECTIVES

Over the last decade, significant advancements have been made in status epilepticus (SE) management, influenced by landmark trials such as ESETT and RAMPART. The objectives of this study were to explore the evolution of drug treatments for patients with SE, to investigate its association with outcomes and mortality, and to evaluate differences in treatment patterns between adults and children for a potential shift in medication trends due to the above mentioned trials.

METHODS

The medical records of patients with SE treated at University Hospital Frankfurt between 2012 and 2021 were evaluated for medication trends and outcomes. Children and adults were analyzed separately and jointly.

RESULTS

This study included 1151 SE episodes in 1021 patients (mean age = 53.3 ± 28.3 years; 52.5 % female [n = 533]). The overall percentage of patients with SE treated prehospital was stable over the last decade. More than half (53.6 %) of children were treated prehospital, compared with less than one-third (26.7 %) of adults. Prehospital midazolam use increased over time, while diazepam use decreased. Lorazepam was the most commonly used benzodiazepine in hospitals in 2012-2013, used in 40.8 % of all episodes. However, its use declined to 27.2 % in 2020-2021, while midazolam use increased to 44.0 %. While the use of older antiseizure medications (ASMs) such as phenobarbital (p = 0.02), phenytoin (p < 0.001), and valproate (p < 0.001) decreased, the use of newer ASMs such as levetiracetam and lacosamide significantly increased (p < 0.001). Propofol and continuous midazolam infusion remained the most used third-line therapy drugs. Overall mortality was 16.5 % at discharge and 18.9 % at 30 days. Mortality rates did not change between 2012 and 2021.

CONCLUSION

Midazolam has become the preferred benzodiazepine in pre- and in-hospital settings, both in children and adults. The same applies to the increased use of levetiracetam and lacosamide over time in children and adults, while phenobarbital, phenytoin, and valproate use decreased. Continuous midazolam infusion and propofol remain the most frequently used anesthetic drugs. Mortality and outcome remain stable despite changes in medication patterns.

Prehospital seizures: Short-term outcomes and risk stratification based in point-of-care testing

BACKGROUND

Information for treatment or hospital derivation of prehospital seizures is limited, impairing patient condition and hindering patients risk assessment by the emergency medical services (EMS). This study aimed to determine the associated factors to clinical impairment, and secondarily, to determine risk factors associated to cumulative in-hospital mortality at 2, 7 and 30 days, in patients presenting prehospital seizures.

METHODS

Prospective, multicentre, EMS-delivery study involving adult subjects with prehospital seizures, including five advanced life support units, 27 basic life support units and four emergency departments in Spain. All bedside variables: including demographic, standard vital signs, prehospital laboratory tests and presence of intoxication or traumatic brain injury (TBI), were analysed to construct a risk model using binary logistic regression and internal validation methods.

RESULTS

A total of 517 patients were considered. Clinical impairment was present in 14.9%, and cumulative in-hospital mortality at 2, 7 and 30-days was 3.4%, 4.6% and 7.7%, respectively. The model for the clinical impairment indicated that respiratory rate, partial pressure of carbon dioxide, blood urea nitrogen, associated TBI or stroke were risk factors; higher Glasgow Coma Scale (GCS) scores mean a lower risk of impairment. Age, potassium, glucose, prehospital use of mechanical ventilation and concomitant stroke were risk factors associated to mortality; and oxygen saturation, a high score in GCS and haemoglobin were protective factors.

CONCLUSION

Our study shows that prehospital variables could reflect the clinical impairment and mortality of patients suffering from seizures. The incorporation of such variables in the prehospital decision-making process could improve patient outcomes.

Management of Status Epilepticus by Different Pediatric Departments: Neurology, Intensive Care, and Emergency Medicine

INTRODUCTION

The aim of this study was to explore the differences in status epilepticus (SE) management among pediatric neurology, emergency medicine, and intensive care specialists in Turkey.

METHODS

A 22-item questionnaire regarding first-, second-, and third-line management strategies of SE including demographic characteristics and common etiologies according to the specialty of participants was mailed to 370 specialists working in Turkey.

RESULTS

A total of 334 participants (response rate 90%) comprising 136 pediatric neurologists, 102 pediatric emergency medicine specialists, and 96 pediatric intensive care specialists completed the survey. While intensive care specialists frequently managed SE due to metabolic and autoimmune reasons, the most common etiologies encountered by emergency medicine specialists were epilepsy and infections. More than half of the intensive care specialists (64.6%) reported using non-BZD antiseizure medications in the 5th minute of the seizure. Most of the neurologists (76.4%) preferred to administer intravenous (IV) levetiracetam infusion as a second-line agent. About half of intensive care specialists and neurologists tried immunomodulatory therapies in super-refractory SE. Intensive care and emergency medicine specialists were less likely to favor ketogenic diet and pyridoxine therapy for the treatment of super-refractory SE. The rate of requesting EEG monitoring to recognize nonconvulsive SE (NCSE) was found to be very low except for neurologists.

CONCLUSION

There was no consensus among neurologists, intensive care specialists, and emergency medicine specialists in the management of SE in Turkey. Familiarity with particular antiseizure medications and the etiologies they manage seem to be the most important factors influencing the attitudes.

Pentylenetetrazole-Induced Seizures Are Increased after Kindling, Exhibiting Vitamin-Responsive Correlations to the Post-Seizures Behavior, Amino Acids Metabolism and Key Metabolic Regulators in the Rat Brain

Epilepsy is characterized by recurrent seizures due to a perturbed balance between glutamate and GABA neurotransmission. Our goal is to reveal the molecular mechanisms of the changes upon repeated challenges of this balance, suggesting knowledge-based neuroprotection. To address this goal, a set of metabolic indicators in the post-seizure rat brain cortex is compared before and after pharmacological kindling with pentylenetetrazole (PTZ). Vitamins B1 and B6 supporting energy and neurotransmitter metabolism are studied as neuroprotectors. PTZ kindling increases the seizure severity (1.3 fold, p < 0.01), elevating post-seizure rearings (1.5 fold, p = 0.03) and steps out of the walls (2 fold, p = 0.01). In the kindled vs. non-kindled rats, the post-seizure p53 level is increased 1.3 fold (p = 0.03), reciprocating a 1.4-fold (p = 0.02) decrease in the activity of 2-oxoglutarate dehydrogenase complex (OGDHC) controlling the glutamate degradation. Further, decreased expression of deacylases SIRT3 (1.4 fold, p = 0.01) and SIRT5 (1.5 fold, p = 0.01) reciprocates increased acetylation of 15 kDa proteins 1.5 fold (p < 0.01). Finally, the kindling abrogates the stress response to multiple saline injections in the control animals, manifested in the increased activities of the pyruvate dehydrogenase complex, malic enzyme, glutamine synthetase and decreased malate dehydrogenase activity. Post-seizure animals demonstrate correlations of p53 expression to the levels of glutamate (r = 0.79, p = 0.05). The correlations of the seizure severity and duration to the levels of GABA (r = 0.59, p = 0.05) and glutamate dehydrogenase activity (r = 0.58, p = 0.02), respectively, are substituted by the correlation of the seizure latency with the OGDHC activity (r = 0.69, p < 0.01) after the vitamins administration, testifying to the vitamins-dependent impact of the kindling on glutamate/GABA metabolism. The vitamins also abrogate the correlations of behavioral parameters with seizure duration (r 0.53-0.59, p < 0.03). Thus, increased seizures and modified post-seizure behavior in rats after PTZ kindling are associated with multiple changes in the vitamin-dependent brain metabolism of amino acids, linked to key metabolic regulators: p53, OGDHC, SIRT3 and SIRT5.

The neuroinflammatory astrocytic P2X7 receptor: Alzheimer's disease, ischemic brain injury, and epileptic state

INTRODUCTION

Astrocytes have previously been considered as cells supporting neuronal functions, but they are now recognized as active players in maintaining central nervous system (CNS) homeostasis. Astrocytes can communicate with other CNS cells, i.e. through the gliotransmitter ATP and P2X7 receptors (Rs).

AREAS COVERED

In this review, we will discuss how the P2X7R initiates the release of gliotransmitters and proinflammatory cytokines/chemokines, thereby establishing a dialog between astrocytes and neurons and, in addition, causing neuroinflammation. In astrocytes, dysregulation of P2X7Rs has been associated with neurodegenerative illnesses such as Alzheimer's disease (AD), as well as the consequences of cerebral ischemic injury and status epilepticus (SE).

EXPERT OPINION

Although all CNS cells are possible sources of ATP release, the targets of this ATP are primarily at microglial cells. However, astrocytes also contain ATP-sensitive P2X7Rs and have in addition the peculiar property over microglia to continuously interact with neurons via not only inflammatory mediators but also gliotransmitters, such as adenosine 5'-triphosphate (ATP), glutamate, γ-amino butyric acid (GABA), and D-serine. Cellular damage arising during AD, cerebral ischemia, and SE via P2X7R activation is superimposed upon the original disease, and their prevention by blood-brain barrier permeable pharmacological antagonists is a valid therapeutic option.

Management of status epilepticus in Malaysia: A national survey of current practice and treatment gap

INTRODUCTION

Early and effective treatment is fundamental in status epilepticus (SE) management. At the initiative of the Epilepsy Council of Malaysia, this study aimed to determine the treatment gap in SE across different healthcare settings in Malaysia.

METHODS

A web-based survey was sent to clinicians involved in the management of SE, across all states and at all levels of healthcare services.

RESULTS

A total of 158 responses were received from 104 health facilities, including 23 tertiary government hospitals (95.8% of all government tertiary hospitals in Malaysia), 4 (80.0%) universities, 14 (6.7%) private, 15 (11.5%) district hospitals and 21 clinics. Intravenous (IV) diazepam was available in 14 (93.3%) district and 33 (80.5%) tertiary hospitals for prehospital management. Non-IV benzodiazepine (rectal diazepam and intramuscular midazolam) was not widely available in prehospital services (75.8% and 51.5%). Intramuscular midazolam was underutilised (60.0% in district and 65.9% in tertiary hospitals). IV sodium valproate and levetiracetam were only available in 66.7% and 53.3% of the district hospitals, respectively. Electroencephalogram (EEG) services were available in only 26.7% of the district hospitals. Non-pharmacological therapies such as ketogenic diet, electroconvulsive therapy, and therapeutic hypothermia were not available in most district and tertiary hospitals for refractory and super-refractory SE.

CONCLUSIONS

We identified several gaps in the current practice of SE management, including limited availability and underutilization of non-IV midazolam in prehospital services, underutilization of non-IV midazolam and other second-line ASMs, and lack of EEG monitoring in district hospitals and limited treatment options for refractory and super-refractory SE in tertiary hospitals.

Status epilepticus and benzodiazepine treatment: Use, underdosing and outcome - insights from a retrospective, multicentre registry

OBJECTIVE

To explore the reasons for and outcomes of non- or undertreatment with benzodiazepines (BZDs) in status epilepticus (SE).

METHODS

We retrospectively analysed all SE patients from the urban area of Cologne over two years.

RESULTS

328 SE patients were eligible, and only 72% were initially treated with BZDs. Of these, only 21.6% were treated sufficiently with BZDs according to current guidelines. SE patients not initially treated with BZDs were significantly older, had less often known epilepsy, had a prolonged arrival time to the emergency room, and presented more often with a non-generalised convulsive semiology. Regarding adequate dosages, patients with a generalised convulsive SE seemed to benefit from a sufficient BZD dosing with significantly shortened mean ventilation duration (37.1 to 208 h), decreased mean intensive care unit (1.7 to 5 days) and in-hospital stay (4.1 to 8.8 days). In contrary, aggressive BZD treatment in non-generalised convulsive SE resulted in a longer inpatient stay (9.2 to 5.8 days) and lower favourable outcome rates at discharge (16% to 63%).

CONCLUSIONS

The current SE treatment guidelines for first-line BZD therapy in SE were violated in most patients. Sufficient BZD dosing was beneficial in generalised convulsive SE, but not in other forms of SE. SE semiology might be crucial for treatment decisions with BZDs. Further treatment evidence especially in non-generalised convulsive SE is urgently needed.

Direct activation of KCC2 arrests benzodiazepine refractory status epilepticus and limits the subsequent neuronal injury in mice

Hyperpolarizing GABA_AR currents, the unitary events that underlie synaptic inhibition, are dependent upon efficient Cl^- extrusion, a process that is facilitated by the neuronal specific K⁺/Cl^- co-transporter KCC2. Its activity is also a determinant of the anticonvulsant efficacy of the canonical GABA_AR-positive allosteric: benzodiazepines (BDZs). Compromised KCC2 activity is implicated in the pathophysiology of status epilepticus (SE), a medical emergency that rapidly becomes refractory to BDZ (BDZ-RSE). Here, we have identified small molecules that directly bind to and activate KCC2, which leads to reduced neuronal Cl^- accumulation and excitability. KCC2 activation does not induce any overt effects on behavior but prevents the development of and terminates ongoing BDZ-RSE. In addition, KCC2 activation reduces neuronal cell death following BDZ-RSE. Collectively, these findings demonstrate that KCC2 activation is a promising strategy to terminate BDZ-resistant seizures and limit the associated neuronal injury.

Neurological Emergencies in the Intensive Care Unit

Neurological emergencies carry significant morbidity and mortality, and it is necessary to have a multidisciplinary approach involving the emergency physician, the neurologist, the intensivist, and the critical care nursing staff. These disorders can be broadly divided into noninfectious and infectious etiologies. In this article, we review a few of the neurological emergencies that present to the neurological intensive unit, with emphasis on convulsive status epileptics, myasthenia gravis, Guillain-Barré syndrome, meningitis, encephalitis, and brain abscess.

Potential risk of liver injury in epileptic patients during COVID-19 pandemic

Most of the antiseizure medications (ASMs) are metabolized in liver and many of them particularly first-generation ASMs have the potential to increase liver enzymes or induce liver injury. Hence, treatment of new onset seizures or epilepsy by ASMs during the course of coronavirus disease 2019 (COVID-19), which could potentially be complicated by hepatic dysfunction, is a challenging clinical issue. Intravenous form of levetiracetam which has no significant hepatic metabolism or drug-drug interaction is often a favorable option to control seizures in acute phase of COVID-19. Administration of enzyme inducer ASMs and valproate with the well-known hepatotoxicity and common drug interactions is not generally recommended. In patients with epilepsy who are under control with potentially hepatotoxic ASMs, close observation and cautious dose reduction or drug switch should be considered if any evidence of hepatic impairment exists. However, risks of possible breakthrough seizures should be weighed against benefits of lowering the hazard of liver injury. In patients with epilepsy who receive polytherapy with ASMs, transient dose modification with the tendency to increase the dose of ASMs with more favorable safety profile and less drug interaction and decrease the dose of drugs with main hepatic metabolism, high protein binding, potential to cause liver injury and known drug-drug reaction should be considered. Finally, decision making should be individualized based on patients’ conditions and course of illness.

The A to F of functional status in the acute setting: A scoping review

Functional status (FSt) describes the phenomenon of prolonged non-epileptic attacks that may be misidentified as Status Epilepticus (SE). The early differentiation between epileptic and functional status is crucial in order to avoid unnecessarily invasive and costly medical escalation in the latter group, including the hazards of overmedication, intubation and intensive care admission. The authors conducted a literature review of available studies describing cases of functional status to extract the common aspects of FSt seizure semiology, investigations used to differentiate from SE, and guidance for managing FSt. A search was carried out using Medline, Embase and PsychInfo databases and 3909 papers were extracted for review. 30 papers were found relevant for inclusion, describing 260 cases of FSt. FSt was found to occur more commonly in younger, female patients with a family history of epilepsy, co-morbid psychiatric diagnosis and following a recent traumatic event. Common clinical features of FSt during and after, the events were identified. While video-EEG remains the gold standard investigation for differentiating FSt from SE, many of the included studies considered the utility of other investigation modalities including serum markers and neuroimaging. One key shortcoming identified within the literature reviewed was a lack of well-defined guidance on the acute management of FSt. We offer an A-F step management plan for the immediate and longer term assessment and treatment of FSt.

Antiseizure and Neuroprotective Efficacy of Midazolam in Comparison with Tezampanel (LY293558) against Soman-Induced Status Epilepticus

Acute exposure to nerve agents induces status epilepticus (SE), which can cause death or long-term brain damage. Diazepam is approved by the FDA for the treatment of nerve agent-induced SE, and midazolam (MDZ) is currently under consideration to replace diazepam. However, animal studies have raised questions about the neuroprotective efficacy of benzodiazepines. Here, we compared the antiseizure and neuroprotective efficacy of MDZ (5 mg/kg) with that of tezampanel (LY293558; 10 mg/kg), an AMPA/GluK1 receptor antagonist, administered 1 h after injection of the nerve agent, soman (1.2 × LD50), in adult male rats. Both of the anticonvulsants promptly stopped SE, with MDZ having a more rapid effect. However, SE reoccurred to a greater extent in the MDZ-treated group, resulting in a significantly longer total duration of SE within 24 h post-exposure compared with the LY293558-treated group. The neuroprotective efficacy of the two drugs was studied in the basolateral amygdala, 30 days post-exposure. Significant neuronal and inter-neuronal loss, reduced ratio of interneurons to the total number of neurons, and reduction in spontaneous inhibitory postsynaptic currents accompanied by increased anxiety were found in the MDZ-treated group. The rats treated with LY293558 did not differ from the control rats (not exposed to soman) in any of these measurements. Thus, LY293558 has significantly greater efficacy than midazolam in protecting against prolonged seizures and brain damage caused by acute nerve agent exposure.

KETASER01 protocol: What went right and what went wrong

Objective

To discuss the results of the KETASER01 trial and the reasons for its failure, particularly in view of future studies.

Methods

KETASER01 is a multicenter, randomized, controlled, open‐label, sequentially designed, non‐profit Italian study that aimed to assess the efficacy of ketamine compared with conventional anesthetics in the treatment of refractory convulsive status epilepticus (RCSE) in children.

Results

During the 5‐year recruitment phase, a total of 76 RCSEs treated with third‐line therapy were observed in five of the 10 participating Centers; only 10 individuals (five for each study arm; five females, mean age 6.5 ± 6.3 years) were enrolled in the KETASER01 study. Two of the five patients (40%) in the experimental arm were successfully treated with ketamine and two of the five (40%) children in the control arm, where successfully treated with thiopental. In the remaining six (60%) enrolled patients, RCSE was not controlled by the randomized anesthetic(s).

Significance

The KETASER01 study was prematurely halted due to low eligibility of patients and no successful recruitment. No conclusions can be drawn regarding the objectives of the study. Here, we discuss the KETASER01 results and critically analyze the reasons for its failure in view of future trials.

Conocimiento de los residentes de especialidades médico-quirúrgicas en Colombia acerca del estado epiléptico

 Introducción: el estado epiléptico es una emergencia con serias implicaciones a nivel social y económico, cuando no se maneja de manera adecuada puede llevar a la muerte. Debe abordarse por el primer especialista que tenga contacto con el paciente. En Colombia no hay estudios acerca de la adherencia a guías de práctica clínica. Objetivo: evaluar cuál es el conocimiento acerca del estado epiléptico en residentes de especialidades médico quirúrgicas en Colombia. Métodos: estudio de corte transversal descriptivo. Se aplicó una encuesta por medio de formulario google, diseñada con base en las guías de práctica clínica rutinaria para el manejo de esta patología. Resultados: respondieron la encuesta 76 residentes de neurología, medicina interna, medicina de urgencias y cuidado crítico, la edad más frecuente fue 26 a 31 años, con una relación hombre mujer de 46/54%. Discusión: las preguntas concernientes a las definiciones operativas y a los tiempos de acción fueron las que tuvieron una mejor consistencia al responderse, hay una importante falencia en la selección y uso de medicamentos anticrisis en el contexto del estado epiléptico, por lo que es importante fortalecer la educación médica en éstos aspectos académicos.

Why won't it stop? The dynamics of benzodiazepine resistance in status epilepticus

Status epilepticus is a life-threatening neurological emergency that affects both adults and children. Approximately 36% of episodes of status epilepticus do not respond to the current preferred first-line treatment, benzodiazepines. The proportion of episodes that are refractory to benzodiazepines is higher in low-income and middle-income countries (LMICs) than in high-income countries (HICs). Evidence suggests that longer episodes of status epilepticus alter brain physiology, thereby contributing to the emergence of benzodiazepine resistance. Such changes include alterations in GABA_A receptor function and in the transmembrane gradient for chloride, both of which erode the ability of benzodiazepines to enhance inhibitory synaptic signalling. Often, current management guidelines for status epilepticus do not account for these duration-related changes in pathophysiology, which might differentially impact individuals in LMICs, where the average time taken to reach medical attention is longer than in HICs. In this Perspective article, we aim to combine clinical insights and the latest evidence from basic science to inspire a new, context-specific approach to efficiently managing status epilepticus.

Management of status epilepticus: a narrative review

Status epilepticus causes prolonged or repetitive seizures that, if left untreated, can lead to neuronal injury, severe disability, coma and death in paediatric and adult populations. While convulsive status epilepticus can be diagnosed using clinical features alone, non-convulsive status epilepticus requires confirmation by electroencephalogram. Early seizure control remains key in preventing the complications of status epilepticus. This is especially true for convulsive status epilepticus, which has stronger evidence supporting the benefit of treatment on outcomes. When status epilepticus becomes refractory, often due to gamma-aminobutyric acid and N-methyl-D-aspartate receptor modulation, anaesthetic drugs are needed to suppress seizure activity, of which there is limited evidence regarding the selection, dose or duration of their use. Seizure monitoring with electroencephalogram is often needed when patients do not return to baseline or during anaesthetic wean; however, it is resource-intensive, costly, only available in highly specialised centres and has not been shown to improve functional outcomes. Thus, the treatment goals and aggressiveness of therapy remain under debate, especially for non-convulsive status epilepticus, where prolonged therapeutic coma can lead to severe complications. This review presents an evidence-based, clinically-oriented and comprehensive review of status epilepticus and its definitions, aetiologies, treatments, outcomes and prognosis at different stages of the patient's journey.

Increased expression of the ATP-gated P2X7 receptor reduces responsiveness to anti-convulsants during status epilepticus in mice

BACKGROUND AND PURPOSE

Refractory status epilepticus is a clinical emergency associated with high mortality and morbidity. Increasing evidence suggests neuroinflammation contributes to the development of drug-refractoriness during status epilepticus. The aim of the present study was to determine the contribution of the ATP-gated P2X7 receptor (P2X7R), previously linked to both inflammation and increased hyperexcitability, to drug-refractory status epilepticus and its therapeutic potential.

EXPERIMENTAL APPROACH

Status epilepticus was induced via a unilateral microinjection of kainic acid into the amygdala in adult mice. Severity of status epilepticus was compared in animals with overexpressing or knock-out of the P2X7R, after inflammatory priming by the pre-injection of bacterial lipopolysaccharide (LPS) and in mice treated with P2X7R-targeting and anti-inflammatory drugs.

KEY RESULTS

P2X7R overexpressing mice were unresponsive to several anticonvulsants (lorazepam, midazolam, phenytoin and carbamazepine) during status epilepticus. P2X7R expression was increased in microglia during status epilepticus, at a time-point when responses to anticonvulsant are reduced. P2X7R overexpression led to a pro-inflammatory phenotype in microglia during status epilepticus and the anti-inflammatory drug minocycline restored normal responsiveness to anticonvulsants in P2X7R overexpressing mice. Pre-treatment of wildtype mice with LPS increased P2X7R levels in the brain and reduced responsiveness to anticonvulsants during status epilepticus, which was overcome by either a genetic deletion of the P2X7R or the administration of the P2X7R antagonists AFC-5128 or ITH15004.

CONCLUSION AND IMPLICATIONS

Our results demonstrate that P2X7R-induced pro-inflammatory effects contribute to resistance to pharmacotherapy during status epilepticus and suggest therapies targeting the P2X7R as novel adjunctive treatments for drug-refractory status epilepticus.

Fosphenytoin alleviates herpes simplex virus infection-induced provoked and spontaneous pain-like behaviors in mice

In this study, we investigated the effects of fosphenytoin (fPHT) a water-soluble prodrug of phenytoin, on the pain responses of a mouse herpes zoster (HZ) pain model. Transdermal herpes simplex virus type 1 (HSV-1) inoculation induced mechanical allodynia and hyperalgesia of the hind paw and spontaneous pain-like behaviors, such as licking the affected skin. Intravenous injection of fPHT (15 and 30 mg/kg) alleviated HSV-1-induced provoked pain (allodynia and hyperalgesia). The suppressive effects of fPHT on provoked pain were weaker than those of diclofenac and pregabalin which were used as positive controls. fPHT, diclofenac, and pregabalin significantly suppressed HSV-1-induced spontaneous pain-like behaviors. Among them, high-dose fPHT (30 mg/kg) showed the strongest suppression. Intravenous fPHT may become a viable option for an acute HZ pain, especially for spontaneous pain.

Misdiagnosis of prolonged psychogenic non-epileptic seizures as status epilepticus: epidemiology and associated risks

OBJECTIVE

To determine the epidemiology of prolonged psychogenic non-epileptic seizures (pPNES) misdiagnosed as status epilepticus, as well as the risks associated with non-indicated treatment.

METHODS

We performed an individual patient data analysis from the Rapid Anticonvulsant Medication Prior to Arrival Trial (RAMPART) and the Established Status Epilepticus Treatment Trial (ESETT) to assess incidence, patient characteristics and clinical course of misdiagnosed pPNES.

RESULTS

Among 980 patients aged 8 years or older diagnosed and treated for status epilepticus in RAMPART and ESETT, 79 (8.1%) were discharged with a final diagnosis of pPNES. The relative incidence was highest in adolescents and young adults (20.1%). The typical female preponderance seen in that age bracket was not evident in children and older adults. Adverse effects, including respiratory depression and intubation, were documented in 26% of patients with pPNES receiving benzodiazepines in RAMPART and 33% of patients receiving additional second-line medication in ESETT. In ESETT, patients who were treated with benzodiazepines before hospital admission had higher rates of unresponsiveness and severe adverse effects than those treated after admission, suggesting cumulative effects of accelerated treatment momentum. Across trials, one in five patients with pPNES were admitted to an intensive care unit.

CONCLUSIONS

Misdiagnosis and treatment of pPNES as status epilepticus are a common and widespread problem with deleterious consequences. Mitigating it will require training of emergency staff in semiological diagnosis. Status epilepticus response protocols should incorporate appropriate diagnostic re-evaluations at each step of treatment escalation, especially in clinical trials.

A Phase 3 open-label study of the efficacy, safety and pharmacokinetics of buccally administered midazolam hydrochloride for the treatment of status epilepticus in pediatric Japanese subjects

BACKGROUND

In Japan, intravenous (IV) administration of antiepileptic drugs in a healthcare setting is the preferred treatment option that is both licensed and recommended for initial treatment of status epilepticus (SE). However, prompt conveyance to a healthcare institution and IV access may be difficult in patients experiencing a seizure and so delay treatment. Thus, there is an unmet need for an alternative effective antiepileptic drug with an easier and more rapid mode of administration. In this study we evaluated a midazolam hydrochloride oromucosal solution (MHOS) that can be simply and rapidly administered to patients in SE.

METHODS

A Phase 3, interventional, multicenter, nonrandomized study was conducted in 28 clinical centers in Japan. Pediatric subjects in convulsive SE received treatment with buccal MHOS with dosage based on their age. The primary efficacy outcome was the percentage of subjects with seizure termination within 10 min and a 30-min absence of visible seizure activity from time of administration. Safety evaluations included respiratory depression and the frequency of treatment-emergent adverse events (TEAEs). Pharmacokinetic (PK) profile was also assessed.

RESULTS

The study population comprised 25 subjects with a median age of 2.8 years and median bodyweight of 13.4 kg. The primary efficacy outcome was achieved in 80 % of subjects; 84 % of subjects had seizure resolution within 10 min. Nine subjects experienced a total of 13 TEAEs, and protocol-defined respiratory depression occurred in one subject. Mean maximum plasma midazolam concentration was 78.0 ng/mL, and mean time to peak concentration was 20.5 min, demonstrating that achieving maximum plasma midazolam concentration is not required for seizure cessation.

CONCLUSIONS

The efficacy, safety and pharmacokinetic profile of MHOS in pediatric Japanese subjects was consistent with that observed in non-Japanese populations. Compared to IV treatments, MHOS offers easier administration which may reduce the time to treatment and thereby minimize the sequelae of prolonged seizures.

Comparative profile of refractory status epilepticus models following exposure of cholinergic agents pilocarpine, DFP, and soman

Status epilepticus (SE) is a medical emergency with continuous seizure activity that causes profound neuronal damage, morbidity, or death. SE incidents can arise spontaneously but mostly are elicited by seizurogenic triggers. Chemoconvulsants such as the muscarinic agonist pilocarpine and, organophosphates (OP) such as the pesticide diisopropylfluorophosphate (DFP) and, the nerve agent soman, can induce SE. Pilocarpine, DFP, and soman share a common feature of cholinergic crisis that transitions into a state of refractory SE, but their comparative profiles remain unclear. Here, we evaluated the comparative convulsant profile of pilocarpine, DFP, and soman to produce refractory SE and brain damage in rats. Behavioral and electrographic seizures were monitored for 24 h after exposure, and the extent of brain injury was determined by histological markers of neuronal injury and degeneration. Seizures were elicited rather slowly after pilocarpine as compared to DFP or soman, which caused rapid onset of spiking that swiftly developed into persistent SE. Time-course of SE activity after DFP was comparable to that after soman, a potent nerve agent. Diazepam controlled pilocarpine-induced SE, but it was ineffective in reducing OP-induced SE. All three agents produced modestly different degrees of neuronal injury and neurodegeneration in the brain. These results reveal distinct convulsant and neuronal injury patterns following exposure to cholinergic agonists, OP pesticides, and nerve agents. A battery of SE models, especially SE induced by cholinergic agents and other etiologies including epilepsy and brain tumors, is essential to identify novel anticonvulsant therapies for the management of refractory SE.

Seizures and Sepsis: A Narrative Review

Patients with sepsis-associated encephalopathy (SAE) can develop convulsive or nonconvulsive seizures. The cytokine storm and the overwhelming systemic inflammation trigger the electric circuits that promote seizures. Several neurologic symptoms, associated with this disease, range from mild consciousness impairment to coma. Focal or generalized convulsive seizures are frequent in sepsis, although nonconvulsive seizures (NCS) are often misdiagnosed and prevalent in SAE. In order to map the trigger zone in all patients that present focal or generalized seizures and also to detect NCS, EEG is indicated but continuous EEG (cEEG) is not very widespread; timing, duration, and efficacy of this tool are still unknown. The long-term risk of seizures in survivors is increased. The typical stepwise approach of seizures management begins with benzodiazepines and follows with anticonvulsants up to anesthetic drugs such as propofol or thiopental, which are able to induce burst suppression and interrupt the pathological electrical circuits. This narrative review discusses pathophysiology, clinical presentation, diagnosis and treatment of seizures in sepsis.

Levetiracetam vs. phenytoin as 2nd-line treatment for status epilepticus: A systematic review and meta-analysis

OBJECTIVE

The objective of the study was to perform a systematic review and meta-analysis to evaluate the efficacy and safety of levetiracetam (LEV) or phenytoin (PHT) as second-line treatment for status epilepticus (SE).

METHODS

PubMed, Cumulative Index to Nursing and Allied Health Literature (CINAHL), Latin American and Caribbean Health Sciences Literature (LILACS), Scopus, the Cochrane Database of Systematic Reviews, the Cochrane Central Register of Controlled Trials, and Google Scholar were assessed for prospective randomized trials comparing LEV with PHT as second-line treatment of SE published from inception until December 18th, 2019. The primary outcome was seizure cessation. Data were analyzed using a random-effects model. Quality analysis was performed using version 2 of the Cochrane risk-of-bias tool (RoB 2). The study protocol was registered on PROSPERO (CRD42020136417).

RESULTS

Nine studies with a total of 1732 patients were included. Overall, seizure cessation occurred in 657 of 887 (74%) of patients in the LEV group and 600 of 845 (71%) in the PHT group. Treatment success did not differ significantly between groups, and the relative risk (RR) was 1.05 (95% confidence interval (CI): 0.98-1.12; I² = 53%). Six of the studies were at low risk of bias, one study had some risk, and two studies had high risk.

CONCLUSIONS

The use of LEV or PHT as second-line agents after benzodiazepine (BZD) for the treatment of SE was not associated with a difference in seizure cessation. Because there are minimal differences in efficacy at this time, clinicians should consider alternative factors when deciding on an antiepileptic drug (AED).

Intramuscular Midazolam for treatment of Status Epilepticus

INTRODUCTION

Status epilepticus (SE) is a common neurological and medical emergency. It has high mortality and morbidity rates, which typically correlate with seizure semiology and duration; therefore, prompt and proper pharmacological intervention is paramount. In a pre-hospital setting, establishing venous access can be difficult, so other routes of drug administration should be considered.

AREAS COVERED

The paper summarizes the data from the literature and provides an evaluation of the efficacy and safety of intramuscular midazolam (IM MDZ) as it pertains to the management of acute seizures and SE.

EXPERT OPINION

The cascade of events involved in the genesis and sustenance of seizures, if not promptly stopped, lead to the perpetuation of the condition and may contribute to the refractoriness of pharmacological treatment. Hence, non-venous routes for drug administration were developed to allow untrained personnel to rapidly stop seizures. Among benzodiazepines (BDZs), IM MDZ is at least as effective and safe as other intravenously administered BDZs. Moreover, thanks to IM MDZ's favorable pharmacodynamic and pharmacokinetic profile, it is a promising alternative to other non-venous drugs such as intranasal-MDZ, buccal-MDZ, and rectal-diazepam in the pre-hospital management of SE cases with motor features.

Lessons from the Established Status Epilepticus Treatment Trial

Convulsive status epilepticus (SE) is a relatively common emergency condition affecting individuals of all ages. The primary goal of treatment is prompt termination of seizures. Where first-line treatment with benzodiazepine has failed to achieve this, a condition known as established SE (ESE), there is uncertainty about which agent to use next. The Established Status Epilepticus Treatment Trial (ESETT) is a 3-arm (valproate (VPA), fosphenytoin (FOS), levetiracetam (LEV)), phase III, double-blind randomized comparative effectiveness study in patients aged 2 years and above with established convulsive SE. Enrollment was completed in January 2019, and the results are expected later this year. We discuss lessons learnt during the conduct of the study in relation to the following: ethical considerations; trial design and practical implementation in emergency settings, including pediatric and adult populations; quality assurance; and outcome determination where treating emergency clinicians may lack specialist expertise. We consider that the ESETT is already informing both clinical practice and future trial design. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".