Treatment of Refractory and Super-refractory Status Epilepticus

Assessment of Seizure Action Plans in Pediatric Convulsive Status Epilepticus: Focus on Benzodiazepine-Responsive and Resistant Cases

Background and Objectives

Optimal acute treatment is crucial in pediatric convulsive status epilepticus (CSE). However, data on the benefits of seizure action plans (SAPs) and treatment algorithm implementation in relation to process and outcome measures in CSE are scarce. Our study examines treatment algorithm adherence in benzodiazepine (BZD)-responsive and BZD-resistant groups and specifically focuses on the relationship with personalized SAPs.

Methods

We performed a prospective observational cohort study evaluating patient care processes and outcomes in young patients with CSE lasting ≥5 minutes, requiring admission and an antiseizure medication(s) (ASM) for seizure termination from February 2016 to July 2018. Patients with infantile spasms, invasive EEG monitoring, unclear seizure duration, unclear ASM administration time, or seizure cluster were excluded. We used univariate statistics to analyze the data.

Results

We enrolled 60 patients (median age 3.7 [1.9-7.0] years, 48% female), including 34 BZD-responsive and 26 BZD-resistant patients. Patients who had access to a personalized SAP, even if it was not adhered to, experienced a median (p25-p75) time to first ASM of 6 minutes (5-18; n = 34). By contrast, patients without access to a personalized SAP had a longer median (p25-p75) time to the first ASM of 15 minutes (8-27; n = 24; p < 0.05). The median (p25-p75) time to administer the first ASM was 6 (5-15; n = 33) minutes in BZD-responsive patients vs 15 (6-32; n = 25; p < 0.05) minutes in BZD-resistant patients. Treatment protocol implementation rates were lower in BZD-resistant vs BZD-responsive patients. The median (p25-p75) time to administer the first ASM was 5 minutes (4-5; n = 14) in patients who implemented a personalized SAP compared with 16 minutes (6-31; n = 20; p < 0.001) in patients without SAP implementation. The median (p25-p75) seizure duration in personalized SAP implementation and nonimplementation groups was 9 (6-16; n = 14) and 22 (11-64; n = 20; p < 0.01) minutes, respectively. The intubation rate was 14% for those who implemented the personalized SAP and 53% for those who did not (p < 0.05).

Discussion

Seizure duration was shorter in patients with personalized SAP, and the time to administer ASM was faster. In addition, BZD-resistant patients were less likely to follow treatment protocols, and the time to first-line therapy was slower. SAP and algorithm implementation was associated with a lower intubation rate, indicating potential benefits, including improved process and patient outcome measures.

Use of oral anti-seizure medication via nasogastric tube to treat IV-diazepam resistant status epilepticus in a setting with limited resources: An observational study

INTRODUCTION

Despite the availability of new antiseizure medications (ASM), status epilepticus (SE) is still associated with a high mortality rate. One third of cases present with benzodiazepine resistance. The availability of intravenous ASMs in Indonesia is limited, meaning that the use of oral ASMs to treat SE is unavoidable. This study aimed to determine whether oral formulations of levetiracetam, topiramate, and valproic acid could successfully terminate diazepam-resistant SE.

METHODS

This prospective cohort study was conducted at Dr. Cipto Mangunkusumo National Hospital between June 2021 and March 2023. Patients with SE aged over 18 years, who achieved clinically apparent seizure cessation with second-line oral ASMs following diazepam, were enrolled. Plasma levels of ASMs were assessed 24 h after the last seizure. Demography, clinical characteristics, and the percentage of successful seizure termination was recorded, as well as duration of seizure termination.

RESULTS

Of the 53 participants, 33, 15, and 5 subjects were administered levetiracetam, topiramate, and valproic acid respectively. Of these, 26 (79 %), 15 (100 %), and 4 (80 %) achieved seizure termination. The median dose required to terminate clinically apparent seizures for oral formulations of levetiracetam, topiramate, and valproic acid were 23 mg/kg, 6 mg/kg, and 20 mg/kg. Seizure termination duration was significantly longer in the topiramate group. Median plasma levels (µg/ml) for levetiracetam, topiramate, and valproic acid among subjects who achieved seizure termination with one second-line ASM were 18.3, 9.5, and 43.2. The 30-day mortality rate among subjects administered levetiracetam, topiramate, and valproic acid, was 15 %, 53 %, and 40 %, respectively.

CONCLUSION

Oral ASMs can be a viable option for the treatment of diazepam-resistant SE in settings with limited resources, where intravenous formulations are not attainable.

Intubation in propofol-treated status epilepticus: a cohort study

Introduction

The management of status epilepticus (SE) often includes endotracheal intubation with mechanical ventilation to address respiratory depression, especially in patients treated with third-line anesthetic agents such as propofol. At our center we use sub-anesthetic propofol as a first line anti-epileptic for SE without intubation. We aimed to assess the performance of our treatment algorithm and to determine whether intubation in these patients improves outcomes.

Methods

All adult patients with SE treated with propofol at a tertiary neuro-intensive care unit from 2015 to 2022 were identified through medical records. Survival without new neurological deficits at discharge was the primary outcome; secondary outcomes were the development of common complications. Descriptive statistics were used to assess general outcomes, and multi-variable logistic regressions were performed to compare outcomes between patients who were intubated while on propofol and those who were not, as well as to compare outcomes according to number of days kept intubated after cessation of propofol.

Results

We identified 162 SE patients treated with low-dose propofol, of which 44 (17%) were not intubated and 118 (83%) were. Our cohort's survival rate was 85%, and survival without new deficits was 42%. Intubation was not associated with improved survival without new neurological deficits (OR = 1.34, 95% CI 0.372-4.831, p = 0.655) or reduction in complications. Additionally, in patients intubated for management of SE, the number of days kept intubated following cessation of propofol was associated with a decrease in survival without new neurological deficits (OR = 0.016, 95% CI 0.000-0.854, p = 0.042).

Conclusion

This study offers encouraging evidence that early sub-anesthetic propofol is a safe and efficient alternative to existing treatment approaches in selected patients. These patients do not require intubation: intubation fails to significantly improve outcomes, and prolonging intubation past cessation of propofol worsens outcomes. These data raise doubts as to the benefits of endotracheal intubation in SE and stress the need to limit the duration of this invasive measure.

Midazolam and Ketamine for Convulsive Status Epilepticus in the Out-of-Hospital Setting

STUDY OBJECTIVE

To determine if ketamine, when added to midazolam for the treatment of out-of-hospital seizures, is associated with an increase in the rate of cessation of convulsions prior to hospital arrival.

METHODS

We performed a retrospective cohort study of out-of-hospital patients with an active convulsive seizure being transported to a hospital by a large emergency medical services system in Florida, using data from August 1, 2015 and August 5, 2024. Per protocol, patients received midazolam first for their seizure. Starting in June 2017, a new protocol was developed in which patients who continued to convulse after midazolam received ketamine. We used propensity score matching and multivariable logistic regression to determine if patients who received ketamine were more likely to stop convulsing prior to hospital arrival than those who received midazolam alone.

RESULTS

Overall, 479 (80.1%) of 598 actively convulsing patients who received 2 doses of midazolam (without subsequent ketamine) had resolution of their convulsions prior to hospital arrival compared with 85 (94.4%) of 90 who received ketamine after midazolam, an absolute difference between groups of 14.3% (95% CI 8.6% to 20.1%). After propensity matching, 82.0% of those in the midazolam only group had resolution of convulsions compared to 94.4% in the ketamine group, a difference of 12.4% (95% CI 3.1% to 21.7%).

CONCLUSION

In this retrospective study of out-of-hospital patients with active convulsive seizures, patients who received ketamine were more likely to have stopped convulsing prior to hospital arrival than those who received midazolam alone.

To what extent does status epilepticus contribute to brain damage in the developmental and epileptic Encephalopathies

This paper is based on a presentation made at the 9th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures in April 2024. Status Epilepticus (SE) is a neurological emergency involving prolonged seizures that disrupt brain function and may cause severe, long-term neurological damage. Developmental and Epileptic Encephalopathies (DEEs), a group of severe genetic disorders with early-onset epilepsy, often exhibit SE episodes that compound their inherent cognitive and developmental challenges. In patients with DEEs, SE may intensify excitotoxicity, metabolic strain, and neuroinflammatory processes, exacerbating developmental delays and cognitive deficits. SE episodes in DEEs frequently resist conventional anti-seizure medications, posing heightened risks of progressive neurological decline and mortality. This paper explores how SE contributes to worsening neurodevelopmental outcomes in DEEs, particularly through sustained structural and functional brain alterations observed in human neuroimaging and animal models. Findings from clinical studies and neuroimaging highlight SE's role in structural damage, including cortical atrophy, hippocampal sclerosis, and gray matter loss. Rodent models replicate SE through chemical or electrical induction, providing insights into SE-induced neurodegeneration, network reorganization, especially in critical areas like the hippocampus, which is more known, however few of scientists look that much outside it. The models reveal a progressive cycle where recurrent SE episodes increase brain excitability, predisposing to further seizures and cumulative developmental impairment. Moreover, genetic animal models of DEEs suggest that early-life seizures exacerbate the severity of the epilepsy phenotype and neurocognitive deficits. This paper underscores the need for advanced, individualized therapies to manage SE in DEE patients and prevent recurrence, aiming to minimize long-term neurological and developmental sequelae.

Effectiveness of Highly Purified Cannabidiol in Refractory and Super-Refractory Status Epilepticus: A Case Series

INTRODUCTION

Refractory and super-refractory status epilepticus are medical emergencies that must be promptly treated in consideration of their high mortality and morbidity rate. Nevertheless, the available evidence of effective treatment for these conditions is scarce. Among novel antiseizure medications (ASMs), highly purified cannabidiol (hpCBD) has shown noteworthy efficacy in reducing seizures in Lennox-Gastaut syndrome, Dravet syndrome, and Tuberous Sclerosis Complex.

CASE PRESENTATION

Here, we present two cases of effective use of hpCBD in both refractory and super- refractory status epilepticus. The administration of the nasogastric tube permitted the resolution of status epilepticus without adverse events. At 6-month follow-up, both patients were on hpCBD treatment, which continued to be efficacious for treating seizures.

CONCLUSION

According to our experience, hpCBD should be taken into consideration as an add-on therapy of RSE and SRSE while also considering the possibility of maintaining this treatment during the follow-up of patients. However, more studies and real-world experiences are needed to better understand its effectiveness in this setting and the interaction with other ASMs.

Effectiveness of Ketamine As a Rescue Drug for Patients Experiencing Benzodiazepine-Resistant Status Epilepticus in the Prehospital Setting

OBJECTIVES

Accumulating basic science data, early clinical findings and various feasibility considerations have provided rationales for administering ketamine as a proposed rescue medication for midazolam-resistant status epilepticus (SE) in the logistically challenging prehospital environment. This report details the multiyear experience of paramedics managing midazolam-resistant SE following the introduction of a ketamine-rescue protocol.

DESIGN

A 7-year, population-based, observational study was conducted to evaluate outcomes of patients treated with IV, intraosseous, intramuscular, or intranasal ketamine for SE despite sufficient midazolam dosings. Tracked outcomes included: 1) rapid/sustained termination of clinical seizures in adults while under paramedics' care; 2) corresponding evaluations in children/adolescents; 3) any concerning observations regarding need for assisted ventilation, intubation, or other active interventions post-ketamine; and 4) any identifiable associations between outcomes and circumstances, demographics, or medical history.

SETTING

Emergency response 9-1-1 system serving a large, diverse U.S. county (jurisdictional population, 961,000/1,769 sq miles).

PATIENTS

Those receiving ketamine from paramedics for persistent seizures.

INTERVENTIONS

Adults and adolescents: 100 mg ketamine IV/intraosseous/intramuscular/intranasal; children: 1 mg/kg intramuscular/intranasal.

MEASUREMENTS AND MAIN RESULTS

Among 81 total cases, 57 involved adults (18-86 yr old) receiving the SE-midazolam + ketamine protocol. Ketamine rapidly terminated convulsions in 56 (98.2%) without recurrence during prehospital and hospital arrival phases. For approved reasons, paramedics administered ketamine directly (no midazolam) in eight adults and one child, terminating convulsions in every case. Among 15 childhood/adolescent cases treated per protocol, ketamine rapidly terminated SE activity in 11, but only mitigated it in four, including two retrospectively judged to involve nonseizure activity and two involving intranasal administration. Among all 81 ketamine-treated cases, there were no identifiable clinically significant complications attributable to ketamine, particularly the need for any additional active interventions.

CONCLUSIONS

Ketamine appeared to be consistently effective in treating adults with ongoing out-of-hospital seizures that were resistant to sufficient dosings of midazolam. Similar results were observed in children/adolescents.

A case of acute functional hemispherotomy in a young woman with hemimegalencephaly and super-refractory status epilepticus

Status epilepticus (SE) is a critical medical emergency that demands immediate and effective intervention. We report a unique case involving a 21-year-old woman with left hemimegalencephaly who was hospitalized for super-refractory status epilepticus (SRSE) that persisted for 8 weeks. Despite extensive treatment efforts including multiple anti-seizure medications, anesthetics, high-dose methylprednisolone, anakinra, magnesium infusion, and a ketogenic diet, her condition remained unchanged. Ultimately, a left functional hemispherotomy was performed, informed by MRI findings and EEG results showing predominantly left-sided epileptic activity. This decision was made collaboratively when all other therapeutic options had been exhausted. Postoperatively, the patient recovered with manageable neurological deficits and a satisfactory quality of life. To our knowledge, this is the first reported case of acute functional hemispherotomy in an adult with hemimegalencephaly and SRSE.

The anesthetic management of a child with ohtahara syndrome and severe stridor: a case report

BACKGROUND

Ohtahara syndrome is a progressive developmental and epileptic encephalopathy that manifests in the early infantile period. This rare condition is characterized by intractable seizures, psychomotor retardation, and poor prognosis. To date, there are a handful of case reports regarding the anesthetic management of children with Ohtahara syndrome. However, limited reports exist of patients with Ohtahara syndrome who present with difficult airways. This report describes our airway findings and general anesthetic management of a pediatric patient with Ohtahara syndrome undergoing diagnostic bronchoscopy for severe inspiratory stridor.

CASE PRESENTATION

A 14-month-old, 9 kg, male patient with Ohtahara syndrome presented with a year-long history of severe inspiratory stridor and was scheduled for bronchoscopy with lavage. On exam, the patient had noisy breathing, was non-verbal with developmental delay, and had poor head control with significant central hypotonia. The patient was induced with ketamine and general anesthesia was maintained with propofol. Bronchoscopic evaluation was completed uneventfully and revealed a diagnosis of laryngotracheomalacia. The patient's breathing was maintained spontaneously throughout the procedure and no seizures were noted. In the post anesthesia care unit, the patient's respiratory and cardiovascular function were stable.

CONCLUSIONS

This report documents the unusual finding of severe inspiratory stridor in a 14-month-old child diagnosed with Ohtahara syndrome and our anesthetic management during their diagnostic bronchoscopy. Currently, documentation of complex airway pathology present in patients with Ohtahara syndrome is limited and should be further evaluated. This will assist pediatric anesthesiologists as these patients may require careful preoperative assessment, thoughtful airway management, and surgical alternatives on standby.

Mir155hg Accelerates Hippocampal Neuron Injury in Convulsive Status Epilepticus by Inhibiting Microglial Phagocytosis

Convulsive status epilepticus (CSE) is a common critical neurological condition that can lead to irreversible hippocampal neuron damage and cognitive dysfunction. Multiple studies have demonstrated the critical roles that long non-coding RNA Mir155hg plays in a variety of diseases. However, less is known about the function and mechanism of Mir155hg in CSE. Here we investigate and elucidate the mechanism underlying the contribution of Mir155hg to CSE-induced hippocampal neuron injury. By applying high-throughput sequencing, we examined the expression of differentially expressed genes in normal and CSE rats. Subsequent RT-qPCR enabled us to measure the level of Mir155hg in rat hippocampal tissue. Targeted knockdown of Mir155hg was achieved by the AAV9 virus. Additionally, we utilized HE and Tunel staining to evaluate neuronal injury. Immunofluorescence (IF), Golgi staining, and brain path clamping were also used to detect the synaptic plasticity of hippocampal neurons. Finally, through IF staining and Sholl analysis, we assessed the degree of microglial phagocytic function. It was found that the expression of Mir155hg was elevated in CSE rats. HE and Tunel staining results showed that Mir155hg knockdown suppressed the hippocampal neuron loss and apoptosis followed CSE. IF, Golgi staining and brain path clamp data found that Mir155hg knockdown enhanced neuronal synaptic plasticity. The results from IF staining and Sholl analysis showed that Mir155hg knockdown enhanced microglial phagocytosis. Our findings suggest that Mir155hg promotes CSE-induced hippocampal neuron injury by inhibiting microglial phagocytosis.

Seizure recurrences in generalized convulsive status epilepticus under sedation: What are its predictors and its impact on outcome?

BACKGROUND

Management of status epilepticus (SE) is focused on the early seizure termination. Refractory SE is an indication for sedation in patients with SE, but up to 75% of patients may be ventilated due to a neurological or respiratory failure. In patients requiring sedation, the clinical assessment is not sufficient to assess seizure control. Identifying those at risk of recurrent seizures could be useful to adapt their management. On the other hand, patients with low risk could benefit from an early withdrawal of sedation to avoid the impact of inappropriate sedation on outcome.

OBJECTIVE

To determine the prevalence and the predictors of uncontrolled SE and its impact on outcome in patients with generalized convulsive SE (GCSE) requiring mechanical ventilation (MV).

METHODS

We retrospectively included patients admitted to the intensive care unit with GCSE requiring MV. Uncontrolled SE was defined as persistent or recurrent seizures during sedation or within 24hours following withdrawal. A multivariable logistic regression model was used to assess the associated factors.

RESULTS

Uncontrolled SE occurred in 37 out of 220 patients (17%). Persistent seizures at admission, higher SAPS II and central nervous system infection were associated with a higher risk of uncontrolled SE. Acute toxic or metabolic etiologies were associated with a decreased risk of uncontrolled SE. In a supplementary analysis, decrease of albumin blood levels was associated with uncontrolled SE. Uncontrolled SE was associated with a poor functional outcome and mortality at 90 days.

CONCLUSIONS

Seventeen percent of patients with a GCSE requiring MV suffered from uncontrolled SE. Etiology and persistent seizures at admission were the main predictors of uncontrolled SE. Patients with uncontrolled SE had a longer duration of sedation and MV, a poor functional outcome and a higher mortality. Further studies are required to determine the impact of continuous electroencephalogram monitoring on the clinical course.

Status Epilepticus: An Update on Pharmacological Management

Status epilepticus (SE) is a neurological emergency that requires timely pharmacological therapy to cease seizure activity. The treatment approach varies based on the time and the treatment stage of SE. Benzodiazepines are considered the first-line therapy during the emergent treatment phase of SE. Antiseizure medicines such as phenytoin, valproic acid, and levetiracetam are recommended during the urgent treatment phase. These drugs appear to have a similar safety and efficacy profile, and individualized therapy should be chosen based on patient characteristics. Midazolam, propofol, pentobarbital, and ketamine are continuous intravenous infusions of anesthetic medications utilized in the refractory SE (RSE) period. The most efficacious pharmacotherapeutic treatments for RSE and superrefractory status epilepticus are not clearly defined.

Efficacy of a combined anti-seizure treatment against cholinergic established status epilepticus following a sarin nerve agent insult in rats

The development of refractory status epilepticus (SE) following sarin intoxication presents a therapeutic challenge. Here, we evaluated the efficacy of delayed combined double or triple treatment in reducing abnormal epileptiform seizure activity (ESA) and the ensuing long-term neuronal insult. SE was induced in rats by exposure to 1.2 LD50 sarin followed by treatment with atropine and TMB4 (TA) 1 min later. Double treatment with ketamine and midazolam or triple treatment with ketamine, midazolam and levetiracetam was administered 30 min post-exposure, and the results were compared to those of single treatment with midazolam alone or triple treatment with ketamine, midazolam, and valproate, which was previously shown to ameliorate this neurological insult. Toxicity and electrocorticogram activity were monitored during the first week, and behavioral evaluations were performed 2 weeks post-exposure, followed by biochemical and immunohistopathological analyses. Both double and triple treatment reduced mortality and enhanced weight recovery compared to TA-only treatment. Triple treatment and, to a lesser extent, double treatment significantly ameliorated the ESA duration. Compared to the TA-only or the TA+ midazolam treatment, both double and triple treatment reduced the sarin-induced increase in the neuroinflammatory marker PGE2 and the brain damage marker TSPO and decreased gliosis, astrocytosis and neuronal damage. Finally, both double and triple treatment prevented a change in behavior, as measured in the open field test. No significant difference was observed between the efficacies of the two triple treatments, and both triple combinations completely prevented brain injury (no differences from the naïve rats). Delayed double and, to a greater extent, triple treatment may serve as an efficacious delayed therapy, preventing brain insult propagation following sarin-induced refractory SE.

Evaluation of Midazolam-Ketamine-Allopregnanolone Combination Therapy against Cholinergic-Induced Status Epilepticus in Rats

Status epilepticus (SE) is a life-threatening development of self-sustaining seizures that becomes resistant to benzodiazepines when treatment is delayed. Benzodiazepine pharmacoresistance is thought in part to result from internalization of synaptic GABAA receptors, which are the main target of the drug. The naturally occurring neurosteroid allopregnanolone is a therapy of interest against SE for its ability to modulate all isoforms of GABAA receptors. Ketamine, an N-methyl-D-aspartate (NMDA) receptor antagonist, has been partially effective in combination with benzodiazepines in mitigating SE-associated neurotoxicity. In this study, allopregnanolone as an adjunct to midazolam or midazolam-ketamine combination therapy was evaluated for efficacy against cholinergic-induced SE. Adult male rats implanted with electroencephalographic (EEG) telemetry devices were exposed to the organophosphorus chemical (OP) soman (GD) and treated with an admix of atropine sulfate and HI-6 at 1 minute after exposure followed by midazolam, midazolam-allopregnanolone, or midazolam-ketamine-allopregnanolone 40 minutes after seizure onset. Neurodegeneration, neuronal loss, and neuroinflammation were assessed 2 weeks after GD exposure. Seizure activity, EEG power integral, and epileptogenesis were also compared among groups. Overall, midazolam-ketamine-allopregnanolone combination therapy was effective in reducing cholinergic-induced toxic signs and neuropathology, particularly in the thalamus and hippocampus. Higher dosage of allopregnanolone administered in combination with midazolam and ketamine was also effective in reducing EEG power integral and epileptogenesis. The current study reports that there is a promising potential of neurosteroids in combination with benzodiazepine and ketamine treatments in a GD model of SE. SIGNIFICANCE STATEMENT: Allopregnanolone, a naturally occurring neurosteroid, reduced pathologies associated with soman (GD) exposure such as epileptogenesis, neurodegeneration, and neuroinflammation, and suppressed GD-induced toxic signs when used as an adjunct to midazolam and ketamine in a delayed treatment model of soman-induced status epilepticus (SE) in rats. However, protection was incomplete, suggesting that further studies are needed to identify optimal combinations of antiseizure medications and routes of administration for maximal efficacy against cholinergic-induced SE.

Protective Activity of Novel Hydrophilic Synthetic Neurosteroids on Organophosphate Status Epilepticus-induced Chronic Epileptic Seizures, Non-Convulsive Discharges, High-Frequency Oscillations, and Electrographic Ictal Biomarkers

Nerve agents and organophosphates (OP) are neurotoxic chemicals that induce acute seizures, status epilepticus (SE), and mortality. Long-term neurologic and neurodegenerative effects manifest months to years after OP exposure. Current benzodiazepine anticonvulsants are ineffective in preventing such long-term neurobehavioral and neuropathological changes. New and effective anticonvulsants are needed for OP intoxication, especially for mitigating the long-term sequelae after acute exposure. We developed neurosteroids as novel anticonvulsants and neuroprotectants in OP exposure models. In this study, we evaluated the long-term efficacy of novel synthetic neurosteroids in preventing the development of chronic epilepsy and hyperexcitable ictal events in a rat OP model of SE. Rats were exposed to the OP nerve agent surrogate diisopropylfluorophosphate (DFP), and the experimental groups were treated with the synthetic neurosteroid valaxanolone (VX) or lysaxanolone (LX) 40 minutes post-exposure in conjunction with midazolam. Video-electroencephalography was monitored for two months to assess spontaneous recurrent seizures (SRS), epileptiform discharges, interictal spikes, and high-frequency oscillations (HFOs). Within 60 days of DFP exposure, rats developed chronic epilepsy characterized by frequent SRS, epileptiform discharges, and HFOs. LX treatment was associated with a dose-dependent reduction of epilepsy occurrence and overall seizure burden with a significant decrease in SRS and epileptiform discharges. It also significantly reduced the occurrence of epileptic biomarkers of HFOs and interictal spikes, indicating potential disease-modifying activity. Similarly, the neurosteroid analog VX also significantly attenuated SRS, discharges, HFOs, and ictal events. These results demonstrate the long-term protective effects of synthetic neurosteroids in the OP-exposed post-SE model, indicating their disease-modifying potential to prevent epilepsy and ictal abnormalities. SIGNIFICANCE STATEMENT: The effects of nerve agents and organophosphate (OP) exposure are persistent, and survivors suffer from a number of devastating, chronic neurological dysfunctions. Currently, there is no specific therapy for preventing this disastrous impact of OP exposure. We propose synthetic neurosteroids that activate tonic inhibition provide viable options for preventing the long-term neurological effects of OP intoxication. The results from this study reveal the disease-modifying potential of two novel synthetic neurosteroids in preventing epileptogenesis and chronic epileptic seizures after OP-induced SE.

ACVIM Consensus Statement on the management of status epilepticus and cluster seizures in dogs and cats

BACKGROUND

Seizure emergencies (ie, status epilepticus [SE] and cluster seizures [CS]), are common challenging disorders with complex pathophysiology, rapidly progressive drug-resistant and self-sustaining character, and high morbidity and mortality. Current treatment approaches are characterized by considerable variations, but official guidelines are lacking.

OBJECTIVES

To establish evidence-based guidelines and an agreement among board-certified specialists for the appropriate management of SE and CS in dogs and cats.

ANIMALS

None.

MATERIALS AND METHODS

A panel of 5 specialists was formed to assess and summarize evidence in the peer-reviewed literature with the aim to establish consensus clinical recommendations. Evidence from veterinary pharmacokinetic studies, basic research, and human medicine also was used to support the panel's recommendations, especially for the interventions where veterinary clinical evidence was lacking.

RESULTS

The majority of the evidence was on the first-line management (ie, benzodiazepines and their various administration routes) in both species. Overall, there was less evidence available on the management of emergency seizure disorders in cats in contrast to dogs. Most recommendations made by the panel were supported by a combination of a moderate level of veterinary clinical evidence and pharmacokinetic data as well as studies in humans and basic research studies.

CONCLUSIONS AND CLINICAL RELEVANCE

Successful management of seizure emergencies should include an early, rapid, and stage-based treatment approach consisting of interventions with moderate to preferably high ACVIM recommendations; management of complications and underlying causes related to seizure emergencies should accompany antiseizure medications.

Ketamine, an Old-New Drug: Uses and Abuses

Ketamine as an old-new drug has a variety of clinical implications. In the last 30 years, ketamine has become popular for acute use in humans. Ketamine in standard doses is principally utilized for the induction and maintenance of surgical procedures. Besides its use in anesthesia and analgesia, recent studies have shown that ketamine has found a place in the treatment of asthma, epilepsy, depression, bipolar affective disorders, alcohol and heroin addiction. Ketamine primarily functions as a noncompetitive antagonist targeting the N-methyl-D-aspartate (NMDA) receptor, but its mechanism of action is complex. It is generally regarded as safe, with low doses and short-term use typically not leading to significant adverse effects. Also, ketamine is known as a powerful psychostimulant. During the past decade, ketamine has been one of the commonly abused drugs.

Lennox-Gastaut syndrome characterized by super-refractory status epilepticus treated with high-dose anesthetics: A case report

RATIONALE

Super-refractory status epilepticus is a serious illness with high morbidity and mortality, which is defined as an SE that continues or recurs 24 hours or more after the onset of anesthesia. Anesthetic agents can be either pro-convulsant or anticonvulsant or both.

PATIENT CONCERNS

Epilepsy occurred at the age of 3 years. At the age of 4 years, generalized tonic-clonic seizure occurred for the first time. The patient was hospitalized at the age of 27 and 28 years for treating status epilepticus. At the age of 33 years, antiepileptic drugs were stopped due to poor appetite. In an early morning, the patient was found delirious with reduced speech.

DIAGNOSIS

Occasionally, the patient blinked his eyelids, or deflected his eyeballs to 1 side. When propofol was lowered to 10 mL/H, the epileptic wave reduced obviously. Afterwards, the patient opened his eyes autonomously and his consciousness gradually recovered. The patient could answer questions, and the limbs had voluntary movements. The patient breathing also gradually recovered, and his urine gradually returned to pale yellow from green. After anesthetic was stopped for 10 days, the patient lost his consciousness again. The patient eyes turned upward frequently, which was relieved in 1 to 2 seconds with an attack once every 2 to 5 minutes.

INTERVENTIONS

Clonazepam was gradually reduced to 2 mg qn, and the patient gradually woke up during this process. The patient was also treated with levetiracetam 1.5 g bid, oxcarbazepine 0.6 g bid, topiramate 50 mg bid and valproate 0.4 g tid.

OUTCOMES

After 1 month follow-up, status epilepticus did not appear again.

LESSONS

Propofol aggravated the tonic seizures. As tonic seizures occur during natural sleep and after sleep induced by various narcotic drugs, the decrease of consciousness level induced by excessive sedation of narcotic drugs has been suggested as the reason for poor seizure control.

Propofol for treatment resistant depression: A randomized controlled trial

Background

Anesthetic agents including ketamine and nitrous oxide have shown antidepressant properties when appropriately dosed. Our recent open-label trial of propofol, an intravenous anesthetic known to elicit transient positive mood effects, suggested that it may also produce robust and durable antidepressant effects when administered at a high dose that elicits an electroencephalographic (EEG) burst-suppression state. Here we report findings from a randomized controlled trial ( NCT03684447 ) that compared two doses of propofol. We hypothesized greater improvement with a high dose that evoked burst suppression versus a low dose that did not.

Methods

Participants with moderate-to-severe, treatment-resistant depression were randomized to a series of 6 treatments at low versus high dose (n=12 per group). Propofol infusions were guided by real-time processed frontal EEG to achieve predetermined pharmacodynamic criteria. The primary and secondary depression outcome measures were the 24-item Hamilton Depression Rating Scale (HDRS-24) and the Patient Health Questionnaire (PHQ-9), respectively. Secondary scales measured suicidal ideation, anxiety, functional impairment, and quality of life.

Results

Treatments were well tolerated and blinding procedures were effective. The mean [95%-CI] change in HDRS-24 score was -5.3 [-10.3, -0.2] for the low-dose group and -9.3 [-12.9, -5.6] for the high-dose group (17% versus 33% reduction). The between-group effect size (standardized mean difference) was -0.56 [-1.39, 0.28]. The group difference was not statistically significant (p=0.24, linear model). The mean change in PHQ-9 score was -2.0 [-3.9, -0.1] for the low dose and -4.8 [-7.7, -2.0] for the high dose. The between-group effect size was -0.73 [-1.59, 0.14] (p=0.09). Secondary outcomes favored the high dose (effect sizes magnitudes 0.1 - 0.9) but did not generally reach statistical significance (p>0.05).

Conclusions

The medium-sized effects observed between doses in this small, controlled, clinical trial suggest that propofol may have dose-dependent antidepressant effects. The findings also provide guidance for subsequent trials. A larger sample size and additional treatments in series are likely to enhance the ability to detect dose-dependent effects. Future work is warranted to investigate potential antidepressant mechanisms and dose optimization.

The Concurrent Use of Phenytoin and Levetiracetam for Seizure Prophylaxis in ICU Patients: The "Arrowhead Rationale"

The administration of multiple antiepileptic drugs (AEDs) is standard practice for neurological intensive care unit (ICU) patients who cannot obtain seizure control with monotherapy. Phenytoin and levetiracetam continue to be highly utilized AEDs for ICU patients due to their efficacy and relatively low cost. However, there is no randomized control trial to date that assesses the efficacy outcomes of the concurrent use of these two medications for ICU patients in convulsive or silent status epilepticus that combats the toxicity with increasing dosages of a single drug by itself. Here, we have analyzed several studies published over the past two decades to better understand whether the concomitant use of these two medications is more efficacious in treating unremitting seizures in ICU patients. Several factors influence which AED is a better fit for ICU patients due to the complexity of their clinical state. Risk for drug interactions, increased incidence of renal and hepatic impairment, and higher need for patient monitoring are daily barriers that determine AED use. After analysis of past research, while the efficacy of concurrent use of levetiracetam and phenytoin is still not fully clear, we offer the "Arrowhead Rationale" for such dual therapy in a subset of patients at our tertiary care trauma and stroke center in Southern California.

Semaphorin 4D induced inhibitory synaptogenesis decreases epileptiform activity and alters progression to Status Epilepticus in mice

Previously we demonstrated that intra-hippocampal infusion of purified, Semaphorin 4D (Sema4D) extracellular domain (ECD) into the mouse hippocampus rapidly promotes formation of GABAergic synapses and decreases seizure susceptibility in mice. Given the relatively fast action of Sema4D treatment revealed by these studies, we sought to determine the time course of Sema4D treatment on hippocampal network activity using an acute hippocampal slice preparation. We performed long-term extracellular recordings from area CA1 encompassing a 2-hour application of Sema4D and found that hippocampal excitation is suppressed for hours following treatment. We also asked if Sema4D treatment could ameliorate seizures in an acute seizure model: the kainic acid (KA) mouse model. We demonstrate that Sema4D treatment delays and suppresses ictal activity, delays the transition to Status Epilepticus (SE), and lessens the severity of SE. Lastly, we sought to explore alternative methods of Sema4D delivery to hippocampus and thus created an Adeno Associated Virus expressing the ECD of Sema4D. Our data reveal that virally delivered, chronically overexpressed Sema4D-ECD promotes GABAergic synapse formation and suppresses ictal activity and progression to SE. These results provide proof of concept that viral delivery of Sema4D is an efficacious and promising delivery method to abate epileptiform activity and progression to SE.

Deep Sedation in Traumatic Brain Injury Patients

Traumatic brain injury (TBI) is one of the leading causes of mortality and disability in adults. In cases of severe TBI, preventing secondary brain injury by managing intracranial hypertension during the acute phase is a critical treatment challenge. Among surgical and medical interventions to control intracranial pressure (ICP), deep sedation can provide comfort to patients and directly control ICP by regulating cerebral metabolism. However, insufficient sedation does not achieve the intended treatment goals, and excessive sedation can lead to fatal sedative-related complications. Therefore, it is important to continuously monitor and titrate sedatives by measuring the appropriate depth of sedation. In this review, we discuss the effectiveness of deep sedation, techniques to monitor the depth of sedation, and the clinical use of recommended sedatives, barbiturates, and propofol in TBI.

A scoping review for building a criticality-based conceptual framework of altered states of consciousness

The healthy conscious brain is thought to operate near a critical state, reflecting optimal information processing and high susceptibility to external stimuli. Conversely, deviations from the critical state are hypothesized to give rise to altered states of consciousness (ASC). Measures of criticality could therefore be an effective way of establishing the conscious state of an individual. Furthermore, characterizing the direction of a deviation from criticality may enable the development of treatment strategies for pathological ASC. The aim of this scoping review is to assess the current evidence supporting the criticality hypothesis, and the use of criticality as a conceptual framework for ASC. Using the PRISMA guidelines, Web of Science and PubMed were searched from inception to February 7th 2022 to find articles relating to measures of criticality across ASC. N = 427 independent papers were initially found on the subject. N = 378 were excluded because they were either: not related to criticality; not related to consciousness; not presenting results from a primary study; presenting model data. N = 49 independent papers were included in the present research, separated in 7 sub-categories of ASC: disorders of consciousness (DOC) (n = 5); sleep (n = 13); anesthesia (n = 18); epilepsy (n = 12); psychedelics and shamanic state of consciousness (n = 4); delirium (n = 1); meditative state (n = 2). Each category included articles suggesting a deviation of the critical state. While most studies were only able to identify a deviation from criticality without being certain of its direction, the preliminary consensus arising from the literature is that non-rapid eye movement (NREM) sleep reflects a subcritical state, epileptic seizures reflect a supercritical state, and psychedelics are closer to the critical state than normal consciousness. This scoping review suggests that, though the literature is limited and methodologically inhomogeneous, ASC are characterized by a deviation from criticality, though its direction is not clearly reported in a majority of studies. Criticality could become, with more extensive research, an effective and objective way to characterize ASC, and help identify therapeutic avenues to improve criticality in pathological brain states. Furthermore, we suggest how anesthesia and psychedelics could potentially be used as neuromodulation techniques to restore criticality in DOC.

2DG and glycolysis as therapeutic targets for status epilepticus

2-deoxy-D-glucose (2DG) is a glucose analog differing from glucose only by removal of an oxygen atom at the 2 position, which prevents the isomerization of glucose-6-phosphate to fructose-6-phosphate, and thereby reversibly inhibits glycolysis. PET studies of regional brain glucose utilization positron-emitting 18F-2DG demonstrate that brain regions generating seizures have diminished glucose utilization during interictal conditions, but rapidly transition to markedly increased glucose delivery and utilization during seizures, particularly in status epilepticus (SE). 2-deoxy-D-glucose has acute antiseizure actions in multiple in vivo and in vitro seizure models, including models of SE induced by the chemo convulsants pilocarpine and kainic acid, suggesting that focal enhanced delivery of 2DG to ictal brain circuits is a potential novel anticonvulsant intervention for the treatment of SE.

Evaluation of intravenous lorazepam dosing strategies and the incidence of refractory status epilepticus

INTRODUCTION

Status epilepticus (SE) is a neurological emergency associated with high mortality if not identified and treated promptly. For the emergent treatment of SE, the recommended intravenous (IV) lorazepam dose is 0.1 mg/kg/dose, up to a maximum of 4 mg. It has been shown that lorazepam is commonly under dosed in SE, but there is conflicting data on whether this has a negative impact on patient outcomes. This study assessed any dose less than 4 mg to help identify the effects of under dosing lorazepam in SE.

METHODS

This was a retrospective cohort study of patients admitted to a quaternary health system between October 1, 2017 and September 30, 2019 that experienced SE and were initially treated with IV lorazepam. Patients were divided into two cohorts, less than 4 mg or 4 mg, based on the initial one-time dose of lorazepam received. The primary outcome was the proportion of patients that progressed to refractory status epilepticus (RSE) that received an initial IV lorazepam dose of 4 mg compared to less than 4 mg for the treatment of SE. Secondary outcomes evaluated include length of stay, mortality, time in SE, number of seizures, cumulative lorazepam dose prior to urgent therapy, number of lorazepam doses prior to urgent therapy, time to urgent therapy, appropriately dosed urgent therapy, and number of antiepileptic drugs given in SE.

RESULTS

One hundred twenty patients were included in this study (107 patients received less than 4 mg and 13 patients received 4 mg). All patients included in the study were greater than 40 kg. The primary outcome of progression to RSE was observed in a significantly greater proportion of patients in the less than 4 mg group compared to the 4 mg group (93 [87%] vs. 8 [62%], p = 0.03). There was no difference in hospital or intensive care unit length of stay. However, there was an increased rate of in-hospital mortality in patients who received 4 mg compared to less than 4 mg (5 [39%] vs. 12[11%], p = 0.02).

DISCUSSION

The majority of patients in the study received less than the recommended dose of IV lorazepam for SE. Patients who received less than 4 mg experienced an increased progression to RSE, which supports current guideline recommended dosing. While there was an increased rate of mortality in patients who received 4 mg compared to less than 4 mg, time in SE was prolonged in the patient population and severity of illness was only available for a limited number of patients included.

Ketamine in Severe Leptomeningeal Pain

Carcinomatosis meningitis is a rare but deadly complication of medulloblastoma. Surgical and systemic treatment options are often limited in advanced stages of the cancer. Meningeal irritation from raised intracranial pressure causes leptomeningeal pain that may respond poorly to opioids and common adjuvant analgesics. We present the case of a terminally ill patient with severe leptomeningeal pain that responded to a trial of ketamine as an adjunct to opioids.

A Validation Study for SHE Score for Acute Subdural Hematoma in the Elderly

OBJECTIVE

The aim of this study was the verification of the Subdural Hematoma in the Elderly (SHE) score proposed by Alford et al. as a mortality predictor in patients older than 65 years with nontraumatic/minor trauma acute subdural hematoma (aSDH). Additionally, we evaluated further predictors associated with poor outcome.

METHODS

Patients were scored according to age (1 point is given if patients were older than 80 years), GCS by admission (1 point for GCS 5-12, 2 points for GCS 3-4), and SDH volume (1 point for volume 50 mL). The sum of points determines the SHE score. Multivariate logistic regression analysis was performed to identify additional independent risk factors associated with 30-day mortality.

RESULTS

We evaluated 131 patients with aSDH who were treated at our institution between 2008 and 2020. We observed the same 30-day mortality rates published by Alford et al.: SHE 0: 4.3% vs. 3.2%, p = 1.0; SHE 1: 12.2% vs. 13.1%, p = 1.0; SHE 2: 36.6% vs. 32.7%, p = 0.8; SHE 3: 97.1% vs. 95.7%, p = 1.0 and SHE 4: 100% vs. 100%, p = 1.0. Additionally, 18 patients who developed status epilepticus (SE) had a mortality of 100 percent regardless of the SHE score. The distribution of SE among the groups was: 1 for SHE 1, 6 for SHE 2, 9 for SHE 3, and 2 for SHE 4. The logistic regression showed the surgical evacuation to be the only significant risk factor for developing the seizure. All patients who developed SE underwent surgery (p = 0.0065). Furthermore, SHE 3 and 4 showed no difference regarding the outcome between surgical and conservative treatment.

CONCLUSIONS

SHE score is a reliable mortality predictor for minor trauma acute subdural hematoma in elderly patients. In addition, we identified status epilepticus as a strong life-expectancy-limiting factor in patients undergoing surgical evacuation.

New-onset non-lesional aphasic status epilepticus. Clinical description, diagnostic clues, and treatment algorithm

OBJECTIVES

De novo aphasic status epilepticus (ASE) in patients without a previous history of epilepsy and without cerebral lesions (aphasic NOSE) is rare. The aim of the study is to describe its clinical characteristics, etiologies, and outcome.

MATERIALS & METHODS

Single-center study including consecutive patients presenting to the emergency department between 2011 and 2019 with acute aphasia, which was finally diagnosed as aphasic NOSE. Subsequent episodes of aphasia (>5 min) were recorded and divided into confirmed ASE and postictal aphasic episodes (non-ASE). Clinical characteristics of the two types of episodes were compared.

RESULTS

Nineteen patients were included, suffering fifty episodes of epileptic aphasia, episodes per patient 2.6 (range 1-7). Fifteen patients (71.4%) were women, mean age at ASE onset was 66.05 years old (SD 6.3). Nine (47%) patients died, 6 of them (66.7%) during the aphasic episode. Ictal EEG was available in 37 episodes, confirming the diagnosis of ASE in 12 episodes; in 8 episodes, the EEG fulfilled the criteria of possible ASE. The most frequent etiologies were inflammatory and vascular. Comparing ASE with non-ASE episodes, ASE was longer than non-ASE (225 vs 65 h, p .024) and was treated more frequently with BZD (76 vs 24%, p .001) but with a longer delay (22.2 vs 1.5 h, p .06).

CONCLUSIONS

ASE is a treatable, highly relapsing emergency, with the subsequent relapses ASE or postictal aphasia. EEG is diagnostic in half of the patients, while in others imaging techniques are also useful. Benzodiazepines should be administered. Persistent aphasia, of more than 65 hours' duration, is highly suggestive of ASE.

Mechanism of cell death pathways in status epilepticus and related therapeutic agents

The most severe form of epilepsy, status epilepticus (SE), causes brain damage and results in the development of recurring seizures. Currently, the management of SE remains a clinical challenge because patients do not respond adequately to conventional treatments. Evidence suggests that neural cell death worsens the occurrence and progression of SE. The main forms of cell death are apoptosis, necroptosis, pyroptosis, and ferroptosis. Herein, these mechanisms of neuronal death in relation to SE and the alleviation of SE by potential modulators that target neuronal death have been reviewed. An understanding of these pathways and their possible roles in SE may assist in the development of SE therapies and in the discovery of new agents.

Good seizure outcome after focal resection surgery for super-refractory status epilepticus: Report of two cases

Background:

There is scarce evidence regarding focal resection surgery for super-refractory status epilepticus (SRSE), which is resistant to general anesthetic treatment over 24 h. We report two patients with SRSE, in whom good seizure outcomes were obtained following focal resection surgery.

Case Description:

Patient 1: A 58-year-old man who underwent left anterior temporal lobectomy with hippocampectomy at the age of 38 years after being diagnosed left medial temporal lobe epilepsy. After 19 years of surgery with no epileptic attacks, the patient developed SRSE. Electroencephalogram (EEG) demonstrated persistence of lateralized periodic discharges in the left frontotemporal region. On the 20^th day after SRSE onset, resection of the frontal lobe and temporal lobe posterior to the resection cavity was performed. Patient 2: A 62-year-old man underwent craniotomy for anaplastic astrocytoma in the left frontal lobe at the age of 34 years. Since the age of 60 years, he developed SRSE 3 times over 1 and 1/12 years. On EEG, repeated ictal discharges were observed at the medial part of the left frontal region during the three SRSEs. Corresponding to the ictal EEG findings, high signals on diffusion-weighted magnetic resonance images and focal hypermetabolism on fluorodeoxyglucose-positron emission tomography were observed around the supplementary motor area, medial to the resection cavity. Resection surgery of the area was performed during the interictal period.

Conclusion:

Good seizure outcome was obtained in the two cases which provide additional support for the recent concept of focal resection surgery as an indication for SRSE.

Status epilepticus in pregnancy: a literature review and a protocol proposal

INTRODUCTION

Status epilepticus (SE) in pregnancy represents a life-threatening medical emergency for both mother and fetus. Pregnancy-related pharmacokinetic modifications and the risks for fetus associated with the use of antiseizure medications (ASMs) and anesthetic drugs complicate SE management. No standardized treatment protocol for SE in pregnancy is available to date.

AREAS COVERED

In this review, we provide an overview of the current literature on the management of SE in pregnancy and we propose a multidisciplinary-based protocol approach.

EXPERT OPINION

Literature data are scarce (mainly anecdotal case reports or small case series). Prompt treatment of SE during pregnancy is paramount and a multidisciplinary team is needed. Benzodiazepines are the drugs of choice for SE in pregnancy. Levetiracetam and phenytoin represent the most suitable second-line agents. Valproic acid should be administered only if other ASMs failed and preferably avoided in the first trimester of pregnancy. For refractory SE, anesthetic drugs are needed, with propofol and midazolam as preferred drugs. Magnesium sulfate is the first-line treatment for SE in eclampsia. Termination of pregnancy, via delivery or abortion, is recommended in case of failure of general anesthetics. Further studies are needed to identify the safest and most effective treatment protocol.

Chinese expert recommendations on ketogenic diet therapy for super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is a serious and life-threatening neurological condition. Ketogenic diet (KD) is a diet characterized by high fat, low carbohydrate, and moderate protein. As KD shows effectiveness in controlling seizures in more than half of SRSE patients, it can be a treatment option for SRSE. Currently, KD treatment for SRSE is based on personal experience and observational evidence has been published. In the context of a lack of a validated guideline, we convened a multicenter expert panel within the China Association Against Epilepsy (CAAE) Ketogenic Diet Commission to work out the Chinese expert recommendations on KD for SRSE. We summarize and discuss the latest clinical practice of KD for SRSE in critical care settings. Recommendations are given on patient selection, the timing of KD, diet implementation, and follow-up. More research data are needed in this area to support better clinical practice.

Pyridoxine-Dependent Epilepsy and Antiquitin Deficiency Resulting in Neonatal-Onset Refractory Seizures

Pyridoxine-dependent epilepsy (PDE) is an autosomal recessive neurometabolic disorder due to a deficiency of α-aminoadipic semialdehyde dehydrogenase (mutation in ALDH7A1 gene), more commonly known as antiquitin (ATQ). ATQ is one of the enzymes involved in lysine oxidation; thus, its deficiency leads to the accumulation of toxic metabolites in body fluids. PDE is characterized by persistent, recurrent neonatal seizures that cannot be well controlled by antiepileptic drugs but are responsive clinically and electrographically to daily pyridoxine (vitamin B6) supplementation. Although the phenotypic spectrum distinguishes between typical and atypical, pyridoxine-dependent is true for each. Diagnosis may pose a challenge mainly due to the rarity of the disorder and the fact that seizures may not occur until childhood or even late adolescence. Moreover, patients may not demonstrate an obvious clinical or electroencephalography response to the initial dose of pyridoxine. Effective treatment requires lifelong pharmacologic supplements of pyridoxine, and dietary lysine restriction and arginine enrichment should improve prognosis and avoid developmental delay and intellectual disability. The purpose of this review is to summarize briefly the latest reports on the etiology, clinical symptoms, diagnosis, and management of patients suffering from pyridoxine-dependent epilepsy.

Successful Use of Inhalational Anesthesia and Electroconvulsive Therapy in a Child with New Onset Prolonged Super-Refractory Status Epilepticus

The treatment of super-refractory status epilepticus (SRSE) and prolonged SRSE rests on urgent seizure control to minimize excitotoxic cerebral damage, other forms of neurologic damage, and multiple medical complications. To date no randomized controlled trials or clear-cut guidelines are available for the management of SRSE. We reported the case of a 10-year-old previously healthy male child patient who presented with a febrile illness and new onset prolonged SRSE that became refractory to multiple antiseizure medications (ASMs). Coma induction with anesthetic agents, 14 ASMs, ketogenic diet, immunotherapy failed to completely control the SRSE in our patient. On day 22, clinical and electroencephalographic seizure control was achieved with isoflurane inhalation anesthesia, which was continued for 3 weeks but was unable to be weaned. From day 57 onwards, electroconvulsive therapy was administered (total 14 sessions that resulted in complete control of seizures). He was discharged on the 80th day.

A retrospective study of 92 children with new-onset refractory status epilepticus

Little is known of the etiology, course, and treatment of new-onset refractory status epilepticus (NORSE) in children. Here we identified etiologies, electroencephalography (EEG) characteristics, and neuroimaging findings among pediatric patients with NORSE and among two patient subgroups, febrile infection-related epilepsy syndrome (FIRES) group and non-FIRES group. We also examined treatments and risk factors related to poor prognosis. Ninety-two children with NORSE were identified in Children's Hospital of Chongqing Medical University between January 1, 2010 and September 1, 2020. The end date was chosen to guarantee at least a 6-month follow-up. Our results indicated that patients with FIRES account for 90% of pediatric patients with NORSE. The clinical, EEG, and neuroimaging results and prognosis were not significantly different between the FIRES group and non-FIRES group of individuals. 68.5% of our patients had unknown etiology, and viral etiology was the most common identified cause (26.1%). Electroencephalography might have a certain diagnostic value for NORSE. A gradual increase in seizure burden was obvious from the onset of disease, and continuous or recurrent ictal discharge lasting ≥ 30 min was quite common in our study. The mortality was 22.8% in our study. Among the 71 surviving patients, the outcome at discharge was poor but improved during follow-up, and 68.5% had good or fair outcomes at their last follow-up. A poor outcome was observed in 39 of 92 cases (42%), with 43.9% and 30% of individuals in the FIRES group and non-FIRES group, respectively, having a poor outcome. The presence of super refractory status epilepticus (SRSE), electrographic seizures and nonconvulsive status epilepticus (NCSE), and diffuse cortical edema and multifocal abnormality may be related to a poor prognosis. Our analysis did not indicate that prognosis was directly related to etiology or treatment. Management of NORSE is challenging, and the role of immunotherapy warrants further investigation.

Efficacy of topiramate as an add-on therapy in patients with refractory status epilepticus: a short systematic review

OBJECTIVE

To identify current evidence on the use of topiramate for refractory status epilepticus.

METHODS

We reviewed the literature to investigate the efficacy of topiramate in the treatment of refractory status epilepticus. The search terms used were "status epilepticus", "refractory", "treatment" and "topiramate". No restrictions were used.

RESULTS

The search yielded 487 articles that reported using topiramate as a treatment for refractory status epilepticus and its outcomes. Case reports, review articles, and animal experiments were excluded. After excluding duplicates and applying inclusion and exclusion criteria, nine studies were included for analyses. Descriptive and qualitative analyses were performed, and the results were as follows: response rates (defined as termination in-hospital until 72 hours after the administration of topiramate) varied from 27% to 100%. The mortality rate varied from 5.9% to 68%. Positive functional long-term outcomes, defined as discharge, back to baseline or rehabilitation, were documented by seven studies, and the rates ranged between 4% and 55%. Most studies reported no or mild adverse effects.

CONCLUSION

Topiramate was effective in terminating refractory status epilepticus, presented relatively low mortality and was well tolerated. Therefore, topiramate could be a good option as a third-line therapy for refractory status epilepticus, but further studies are necessary.

G-alpha interacting protein interacting protein, C terminus 1 regulates epileptogenesis by increasing the expression of metabotropic glutamate receptor 7

Aims

It has been reported that the G‐alpha interacting protein (GAIP) interacting protein, C terminus 1 (GIPC1/GIPC) engages in vesicular trafficking, receptor transport and expression, and endocytosis. However, its role in epilepsy is unclear. Therefore, in this study, we aimed to explore the role of GIPC1 in epilepsy and its possible underlying mechanism.

Methods

The expression patterns of GIPC1 in patients with temporal lobe epilepsy (TLE) and in mice with kainic acid (KA)‐induced epilepsy were detected. Behavioral video monitoring and hippocampal local field potential (LFP) recordings were carried out to determine the role of GIPC1 in epileptogenesis after overexpression of GIPC1. Coimmunoprecipitation (Co‐IP) assay and high‐resolution immunofluorescence staining were conducted to investigate the relationship between GIPC1 and metabotropic glutamate receptor 7 (mGluR7). In addition, the expression of mGluR7 after overexpression of GIPC1 was measured, and behavioral video monitoring and LFP recordings after antagonism of mGluR7 were performed to explore the possible mechanism mediated by GIPC1.

Results

GIPC1 was downregulated in the brain tissues of patients with TLE and mice with KA‐induced epilepsy. After overexpression of GIPC1, prolonged latency period, decreased epileptic seizures and reduced seizure severity in behavioral analyses, and fewer and shorter abnormal brain discharges in LFP recordings of KA‐induced epileptic mice were observed. The result of the Co‐IP assay showed the interaction between GIPC1 and mGluR7, and the high‐resolution immunofluorescence staining also showed the colocalization of these two proteins. Additionally, along with GIPC1 overexpression, the total and cell membrane expression levels of mGluR7 were also increased. And after antagonism of mGluR7, increased epileptic seizures and aggravated seizure severity in behavioral analyses and more and longer abnormal brain discharges in LFP recordings were observed.

Conclusion

GIPC1 regulates epileptogenesis by interacting with mGluR7 and increasing its expression.

Treating Status Epilepticus: Phenytoin Versus Levetiracetam

For decades, phenytoin has been the drug of choice for the treatment of epilepsy but also the second-line treatment for status epilepticus (SE). However, newer antiepileptic drugs (AEDs) have emerged as safer alternatives for the suppression of seizures. Consequently, phenytoin has recently fallen under scrutiny in the research world, prompting many studies to compare its efficacy to these other drugs, most notably levetiracetam. Levetiracetam is a second-generation AED, which is gaining wide clinical use as the second-line agent in treating SE patients. This review focuses on several clinical studies that have directly compared the effectiveness of phenytoin and levetiracetam in suppressing SE seizure activity. Additionally, this review highlights several advantages of using levetiracetam over phenytoin in this clinical context.

Review and Updates on the Treatment of Refractory and Super Refractory Status Epilepticus

Refractory and super-refractory status epilepticus (RSE and SRSE) are life-threatening conditions requiring prompt initiation of appropriate treatment to avoid permanent neurological damage and reduce morbidity and mortality. RSE is defined as status epilepticus that persists despite administering at least two appropriately dosed parenteral medications, including a benzodiazepine. SRSE is status epilepticus that persists at least 24 h after adding at least one appropriately dosed continuous anesthetic (i.e., midazolam, propofol, pentobarbital, and ketamine). Other therapeutic interventions include immunotherapy, neuromodulation, ketogenic diet, or even surgical intervention in certain cases. Continuous electroencephalogram is an essential monitoring tool for diagnosis and treatment. In this review, we focus on the diagnosis and treatment of RSE and SRSE.

Super-Refractory Status Epilepticus: Prognosis and Recent Advances in Management

Super-refractory status epilepticus (SRSE) is a life-threatening neurological emergency with high morbidity and mortality. It is defined as “status epilepticus (SE) that continues or recurs 24 hours or more after the onset of anesthesia, including those cases in which SE recurs on the reduction or withdrawal of anesthesia.” This condition is resistant to normal protocols used in the treatment of status epilepticus and exposes patients to increased risks of neuronal death, neuronal injury, and disruption of neuronal networks if not treated in a timely manner. It is mainly seen in patients with severe acute onset brain injury or presentation of new-onset refractory status epilepticus (NORSE). The mortality, neurological deficits, and functional impairments are significant depending on the duration of status epilepticus and the resultant brain damage. Research is underway to find the cure for this devastating neurological condition. In this review, we will discuss the wide range of therapies used in the management of SRSE, provide suggestions regarding its treatment, and comment on future directions. The therapies evaluated include traditional and alternative anesthetic agents with antiepileptic agents. The other emerging therapies include hypothermia, steroids, immunosuppressive agents, electrical and magnetic stimulation therapies, emergent respective epilepsy surgery, the ketogenic diet, pyridoxine infusion, cerebrospinal fluid drainage, and magnesium infusion. To date, there is a lack of robust published data regarding the safety and effectiveness of various therapies, and there continues to be a need for large randomized multicenter trials comparing newer therapies to treat this refractory condition.

Fenfluramine in the successful treatment of super-refractory status epilepticus in a patient with Dravet syndrome

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Dravet syndrome (DS) patient in super-refractory status epilepticus (SRSE) for 5 weeks.

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Add-on fenfluramine (FFA) successfully treated SRSE in DS.

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Most effective dose of FFA was 0.7 mg/kg/day.

•

Long-term FFA provided >90% reduction in seizures and prevented status epilepticus.

•

FFA maintenance also resulted in improvement of neurocognitive function.

A 20-year-old woman with Dravet syndrome and multiple prior episodes of status epilepticus presented to our hospital in November 2018 in super-refractory status epilepticus. After 5 weeks of unsuccessful continuous treatment with anesthetics, including pentobarbital and ketamine, we sought and were granted an emergency approval by the United States Food and Drug Administration to administer fenfluramine, an investigational new drug, to this patient. One week of treatment with fenfluramine at 0.4 mg/kg/day was ineffective. The dose of fenfluramine was titrated to 0.7 mg/kg/day, and after 1 week, electrographic seizures ceased. One week later, the patient was seizure-free and off all anesthetic agents. Add-on treatment with fenfluramine was continued with no further episodes of status epilepticus and >90% reduction in tonic-clonic seizures. This case report illustrates the potential for fenfluramine to prevent reoccurrence of status epilepticus and to manage super-refractory status epilepticus in patients with Dravet syndrome.

Mechanisms of Drug Resistance in the Pathogenesis of Epilepsy: Role of Neuroinflammation. A Literature Review

Epilepsy is a chronic neurological disorder characterized by recurring spontaneous seizures. Drug resistance appears in 30% of patients and it can lead to premature death, brain damage or a reduced quality of life. The purpose of the study was to analyze the drug resistance mechanisms, especially neuroinflammation, in the epileptogenesis. The information bases of biomedical literature Scopus, PubMed, Google Scholar and SciVerse were used. To obtain full-text documents, electronic resources of PubMed Central and Research Gate were used. The article examines the recent research of the mechanisms of drug resistance in epilepsy and discusses the hypotheses of drug resistance development (genetic, epigenetic, target hypothesis, etc.). Drug-resistant epilepsy is associated with neuroinflammatory, autoimmune and neurodegenerative processes. Neuroinflammation causes immune, pathophysiological, biochemical and psychological consequences. Focal or systemic unregulated inflammatory processes lead to the formation of aberrant neural connections and hyperexcitable neural networks. Inflammatory mediators affect the endothelium of cerebral vessels, destroy contacts between endothelial cells and induce abnormal angiogenesis (the formation of “leaky” vessels), thereby affecting the blood–brain barrier permeability. Thus, the analysis of pro-inflammatory and other components of epileptogenesis can contribute to the further development of the therapeutic treatment of drug-resistant epilepsy.

A Comparison of Seizure Prophylaxis: Phenytoin Versus Levetiracetam

Phenytoin and levetiracetam are both antiepileptic drugs (AEDs) used for seizure prophylaxis. However, to date, there is a paucity of literature comparing their relative efficacies. In this narrative review, we seek to determine if there is greater advantage between the two AEDs, levetiracetam and phenytoin. Phenytoin is the more traditional AED of the two as it has been medically used for a much longer time than levetiracetam. However, levetiracetam, the newer AED of the two, has fewer side effects than phenytoin and fewer drug-drug interactions. Although past studies have aimed to compare the efficacy of phenytoin versus levetiracetam, there is no clear consensus as to if there is a clinical advantage to one over the other. Here, we have analyzed several studies published between 2013 and 2020 in the hopes of having a better understanding of which AED is more efficient in preventing seizures. Many factors can contribute to determining which AED is the better fit for patients, including pricing, risk for adverse drug effects, and level of patient monitoring. After analysis of past research, the more advantageous AED still remains unclear. Future research must be conducted that involve large patient populations, stratifying age populations, and studies analyzing cost-effectiveness to clearly determine if there is indeed a more advantageous AED between levetiracetam and phenytoin.

Super refractory status in a case of Febrile Infection-Related Epilepsy Syndrome due to hemophagocytic lymphocytic histiocytosis

A 14-year-old boy presented with a prodromal respiratory infection followed by super refractory status epilepticus. A diagnosis of Febrile Infection-Related Epilepsy Syndrome (FIRES) was made. Initial MRI study and CSF analysis were normal. He required multiple anticonvulsants owing to the refractory nature of the seizures. The course of the illness was rather stormy, laced with various medical problems viz. hepatic dysfunction, sepsis, hemodynamic, and hematological abnormalities which posed several challenges in the management. Hemophagocytic lymphocytic histiocytosis (HLH) was identified as the etiology of the illness and was treated but without success. The case report highlights the several immunomodulatory strategies that were employed to treat the disease, despite which the outcome was unfavorable.

A retrospective cohort study of super-refractory status epilepticus in a tertiary neuro-ICU setting

PURPOSE

Over the last decade, the range of treatments available for the management of super-refractory status epilepticus (SRSE) has expanded. However, it is unclear whether this has had an impact on its high mortality and morbidity. The aim of this study was to investigate whether there has been a change in the outcome of SRSE over time in a neurological intensive care unit (ICU) within a tertiary centre.

METHODS

Analysis of a retrospective cohort of 53 admissions from 45 patients to the neurological ICU at the National Hospital for Neurology and Neurosurgery, Queen Square, London, between January 2004 and September 2018.

RESULTS

Significant reductions were observed in both duration of SRSE over time and in the time spent in ICU, suggesting that treatment quality has improved over time. A median of four antiseizure drugs (ASDs) were given prior to seizure resolution. In 23 % resolution of SRSE occurred following optimisation of current treatment rather than introduction of a new ASD. The mortality rate was very low at 11 % by 6 months; however, there was no indication of improvement in outcome as all surviving patients had a modified Rankin scale score of 3-5 upon discharge from ICU, classified as moderate-to-severe disability.

CONCLUSION

Neither the survival rate nor the outcome score changed significantly over time, suggesting that changes in the treatment of SRSE have had no impact on patient outcome.

Consensus Statement on Analgo-sedation in Neurocritical Care and Review of Literature

Aim and objective

Our main objective in developing this consensus is to bring together a set of most agreed-upon statements from a panel of global experts that would act as a guide for clinicians working in neurocritical care units (NCCUs).

Background

Given the physiological benefits of analgo-sedation in the NCCU, there is little information on their tailoring in the NCCU. This lack of evidence and guidelines on the use of sedation and analgesia in patients with neurological injury leads to a variation in clinical care based on patient requirements and institutional protocols.

Review results

Thirty-nine international experts agreed to be a member of this consensus panel. A Delphi method based on a Web-based questionnaire developed with Google Forms on a secure institute server was used to seek opinions of experts. Questions were related to sedation and analgesia in the neurocritical care unit. A predefined threshold of agreement was established as 70% to support any recommendation, strong, moderate, or weak. No recommendations were made below this threshold. Responses were collected from all the experts, summated, and expressed as percentage (%). After three rounds, consensus could be reached for 6 statements related to analgesia and 5 statements related to sedation. Consensus could not be reached for 10 statements related to analgesia and 5 statements related to sedation.

Conclusion

This global consensus statement may help in guiding practitioners in clinical decision-making regarding analgo-sedation in the NCCUs, thereby helping in improving patient recovery profiles.

Clinical significance

In the lack of high-level evidence, the recommendations may be seen as the current best clinical practice.

How to cite this article

Prabhakar H, Tripathy S, Gupta N, Singhal V, Mahajan C, Kapoor I, et al. Consensus Statement on Analgo-sedation in Neurocritical Care and Review of Literature. Indian J Crit Care Med 2021;25(2):126–133.

Anti-N-methyl-d-aspartate Receptor Encephalitis Presenting as New-onset Refractory Status Epilepticus Responding to Rituximab in an Adolescent Girl

New-onset refractory status epilepticus (NORSE) is defined as a refractory status epilepticus (SE) in a patient, without a clear acute or active structural, toxic, or metabolic cause, previous active epilepsy, or preexisting relevant neurological disorder. Cryptogenic NORSE cases, often immunotherapy is considered empirically as a favorable response, have been documented in anecdotal case reports. More than half of children with the anti-N-methyl-D-aspartate receptor (NMDAR) encephalitis develop seizures and SE may also occur during the clinical course. But NORSE as a presenting feature of anti-NMDAR encephalitis is extremely rare, as most children present with subacute onset neuropsychiatric and extrapyramidal features. We are describing one such case in an adolescent girl with anti-NMDAR encephalitis, in whom even intravenous anesthetic infusion and first-line immunotherapy including corticosteroid and IVIG were insufficient to achieve seizure control. Super refractory left focal SE in this child resolved after 96 h of injection rituximab, following which intravenous anesthetics could be tapered and child survived with only mild functional limitation on follow-up at 6 months. In children with cryptogenic NORSE, the clinicians need to rule out the cerebrospinal fluid anti-NMDAR antibody. Rituximab is one of the most promising second-line immunotherapy options in children with anti-NMDAR encephalitis for achieving seizure control and inducing long-term remission.