Timing in the treatment of status epilepticus: From basics to the clinic

Increasing Provider Utilization of a Seizure Action Plan in the Outpatient Setting

OBJECTIVES

A seizure action plan (SAP) is a powerful tool that provides actionable information for caregivers during seizures. Guidelines have expressed the need for individualized SAPs. Our quality improvement team aimed to increase implementation of an SAP within a pediatric tertiary center, initially among epilepsy providers and expanded to all neurology providers.

METHODS

Process changes were implemented using Plan-Do-Study-Act cycles and data were evaluated monthly using control charts. The team focused on tracking patients who received SAPs and identified opportunities for improvement, including reminders within the electronic medical record, and standardizing clinic processes. A secondary analysis was performed to trend emergency department (ED) use among our patient population.

RESULTS

The SAP utilization rate among epilepsy providers increased from a baseline of 39% to 78% by December 2019 and reached the goal of 85% by June 2020, with a further increase to 92% by February 2022 and maintained. The SAP utilization rate among general neurology providers increased from 43% in 2018 to 85% by July 2020, and further increased to 93% by February 2022 and maintained. ED visits of established patients with epilepsy decreased from a baseline of 10.2 per 1000 to 7.5 per 1000.

CONCLUSIONS

Quality improvement methodologies increased the utilization of a standardized SAP within neurology outpatient care centers. The SAP is a simplified tool that allows patients and providers to navigate a complex health care system. The utility of an SAP may potentially extend to minimizing unnecessary ED visits.

Evaluation of a Seizure Action Plan in an Adult Epilepsy Center

Background

Seizure action plans (SAPs) provide valuable information for patients to manage seizure emergencies, but are underutilized in adult epilepsy centers. The purpose of this project was to implement a structured SAP for adult patients with epilepsy.

Methods

A pre/postimplementation design was used. Provider SAP utilization rates were analyzed over a 16-week period. A pre and postimplementation survey assessed participant perceived impact of the SAP on knowledge and comfort associated with managing seizure emergencies. Provider barriers and facilitators were also assessed.

Results

Average provider SAP utilization rate was 51.45%. A total of 204 participants completed the surveys, which showed a significant increase in knowledge and comfort for all items, p < 0.001. At postsurvey analysis, 98% of participants felt that all patients with epilepsy should have a SAP regardless of seizure burden.

Discussion

Implementing a structured SAP increased provider utilization and patient and care partner knowledge and comfort of managing seizure emergencies.

Rapid Rescue Treatment with Diazepam Nasal Spray Leads to Faster Seizure Cluster Termination in Epilepsy: An Exploratory Post Hoc Cohort Analysis

INTRODUCTION

Although prompt treatment of status epilepticus is standard of care, the effect of timing of rescue therapy administration for seizure clusters in epilepsy remains unknown. Seizure clusters are a rare but clinically important condition, and benzodiazepines are the cornerstone rescue therapy for seizure clusters in epilepsy. We characterized temporal patterns from a large dataset of treated seizure clusters in the safety study of diazepam nasal spray.

METHODS

This post hoc analysis used timing data of treated seizure clusters recorded by care partners and patients in seizure diaries during a 1-year safety study. Data analysis used time from seizure start to administration of diazepam.

RESULTS

From 4466 observations, 3225 had data meeting criteria for analysis. Overall, median times from seizure start to dose administration, dose administration to seizure termination, and total seizure duration were 2, 3, and 7 min, respectively. In seizure clusters treated in < 5 min (median 1.0 min), median time from dose to seizure termination was 2.0 min, and median total seizure duration was 4.0 min. Among seizure clusters treated in ≥ 5 min (median 10.0 min), median time to seizure termination was 10.0 min, and median total seizure duration was 23.0 min. Previously published safety results reported that over a mean participation of 1.5 years, 82.2% of patients had ≥ 1 treatment-emergent adverse events (TEAEs) irrespective of relationship to treatment, including 30.7% with serious TEAEs; 18.4% had TEAEs deemed at least possibly related to the study drug, none of which were serious. There were no events of cardiorespiratory depression.

CONCLUSION

Echoing the importance of early use of benzodiazepines in status epilepticus, the findings from this exploratory analysis of patients with refractory epilepsy and frequent seizure clusters identify a potential benefit of early diazepam nasal spray treatment leading to faster seizure resolution within the seizure cluster. Trial Registration Information: ClinicalTrials.gov identifier NCT02721069 ( https://clinicaltrials.gov/ct2/show/NCT02721069 ).

Neurosteroids as Novel Anticonvulsants for Refractory Status Epilepticus and Medical Countermeasures for Nerve Agents: A 15-Year Journey to Bring Ganaxolone from Bench to Clinic

This article describes recent advances in the use of neurosteroids as novel anticonvulsants for refractory status epilepticus (RSE) and as medical countermeasures (MCs) for organophosphates and chemical nerve agents (OPNAs). We highlight a comprehensive 15-year journey to bring the synthetic neurosteroid ganaxolone (GX) from bench to clinic. RSE, including when caused by nerve agents, is associated with devastating morbidity and permanent long-term neurologic dysfunction. Although recent approval of benzodiazepines such as intranasal midazolam and intranasal midazolam offers improved control of acute seizures, novel anticonvulsants are needed to suppress RSE and improve neurologic function outcomes. Currently, few anticonvulsant MCs exist for victims of OPNA exposure and RSE. Standard-of-care MCs for postexposure treatment include benzodiazepines, which do not effectively prevent or mitigate seizures resulting from nerve agent intoxication, leaving an urgent unmet medical need for new anticonvulsants for RSE. Recently, we pioneered neurosteroids as next-generation anticonvulsants that are superior to benzodiazepines for treatment of OPNA intoxication and RSE. Because GX and related neurosteroids that activate extrasynaptic GABA-A receptors rapidly control seizures and offer robust neuroprotection by reducing neuronal damage and neuroinflammation, they effectively improve neurologic outcomes after acute OPNA exposure and RSE. GX has been selected for advanced, Biomedical Advanced Research and Development Authority-supported phase 3 trials of RSE and nerve agent seizures. In addition, in mechanistic studies of neurosteroids at extrasynaptic receptors, we identified novel synthetic analogs with features that are superior to GX for current medical needs. Development of new MCs for RSE is complex, tedious, and uncertain due to scientific and regulatory challenges. Thus, further research will be critical to fill key gaps in evaluating RSE and anticonvulsants in vulnerable (pediatric and geriatric) populations and military persons. SIGNIFICANCE STATEMENT: Following organophosphate and nerve agent intoxication, refractory status epilepticus (RSE) occurs despite benzodiazepine treatment. RSE occurs in 40% of status epilepticus patients, with a 35% mortality rate and significant neurological morbidity in survivors. To treat RSE, neurosteroids are better anticonvulsants than benzodiazepines. Our pioneering use of neurosteroids for RSE and nerve agents led us to develop ganaxolone as a novel anticonvulsant and neuroprotectant with significantly improved neurological outcomes. This article describes the bench-to-bedside journey of bringing neurosteroid therapy to patients, with ganaxolone leading the way.

Sustained effort network for treatment of status epilepticus/European academy of neurology registry on adult refractory status epilepticus (SENSE-II/AROUSE)

BACKGROUND

Status Epilepticus (SE) is a common neurological emergency associated with a high rate of functional decline and mortality. Large randomized trials have addressed the early phases of treatment for convulsive SE. However, evidence regarding third-line anesthetic treatment and the treatment of nonconvulsive status epilepticus (NCSE) is scarce. One trial addressing management of refractory SE with deep general anesthesia was terminated early due to insufficient recruitment. Multicenter prospective registries, including the Sustained Effort Network for treatment of Status Epilepticus (SENSE), have shed some light on these questions, but many answers are still lacking, such as the influence exerted by distinct EEG patterns in NCSE on the outcome. We therefore initiated a new prospective multicenter observational registry to collect clinical and EEG data that combined may further help in clinical decision-making and defining SE.

METHODS

Sustained effort network for treatment of status epilepticus/European Academy of Neurology Registry on refractory Status Epilepticus (SENSE-II/AROUSE) is a prospective, multicenter registry for patients treated for SE. The primary objectives are to document patient and SE characteristics, treatment modalities, EEG, neuroimaging data, and outcome of consecutive adults admitted for SE treatment in each of the participating centers and to identify factors associated with outcome and refractoriness. To reach sufficient statistical power for multivariate analysis, a cohort size of 3000 patients is targeted.

DISCUSSION

The data collected for the registry will provide both valuable EEG data and information about specific treatment steps in different patient groups with SE. Eventually, the data will support clinical decision-making and may further guide the planning of clinical trials. Finally, it could help to redefine NCSE and its management.

TRIAL REGISTRATION

NCT number: NCT05839418.

Economic review of point-of-care EEG

Aims: Point-of-care electroencephalogram (POC-EEG) is an acute care bedside screening tool for the identification of nonconvulsive seizures (NCS) and nonconvulsive status epilepticus (NCSE). The objective of this narrative review is to describe the economic themes related to POC-EEG in the United States (US).Materials and methods: We examined peer-reviewed, published manuscripts on the economic findings of POC-EEG for bedside use in US hospitals, which included those found through targeted searches on PubMed and Google Scholar. Conference abstracts, gray literature offerings, frank advertisements, white papers, and studies conducted outside the US were excluded.Results: Twelve manuscripts were identified and reviewed; results were then grouped into four categories of economic evidence. First, POC-EEG usage was associated with clinical management amendments and antiseizure medication reductions. Second, POC-EEG was correlated with fewer unnecessary transfers to other facilities for monitoring and reduced hospital length of stay (LOS). Third, when identifying NCS or NCSE onsite, POC-EEG was associated with greater reimbursement in Medical Severity-Diagnosis Related Group coding. Fourth, POC-EEG may lower labor costs via decreasing after-hours requests to EEG technologists for conventional EEG (convEEG).Limitations: We conducted a narrative review, not a systematic review. The studies were observational and utilized one rapid circumferential headband system, which limited generalizability of the findings and indicated publication bias. Some sample sizes were small and hospital characteristics may not represent all US hospitals. POC-EEG studies in pediatric populations were also lacking. Ultimately, further research is justified.Conclusions: POC-EEG is a rapid screening tool for NCS and NCSE in critical care and emergency medicine with potential financial benefits through refining clinical management, reducing unnecessary patient transfers and hospital LOS, improving reimbursement, and mitigating burdens on healthcare staff and hospitals. Since POC-EEG has limitations (i.e. no video component and reduced montage), the studies asserted that it did not replace convEEG.

Risk model of seizure cluster or status epilepticus and intervention in the emergency department

OBJECTIVES

To identify possible predictors of seizure cluster or status epilepticus (SE) and to evaluate whether these patients receive greater interventions in emergency departments.

METHODOLOGY

We conducted a secondary analysis of the ACESUR Registry, a multipurpose, observational, prospective, multicentre registry of adult patients with seizures from 18 emergency departments. Clinical and care-related variables were collected. We identified risk factors and risk models for seizure cluster or SE and assessed the effect of interventions by prehospital emergency services and the hospital emergency department.

RESULTS

We identified a total of 186 (28%) patients from the ACESUR registry with seizure cluster (126 [19%]) or SE (60 [9%]); the remaining 478 patients (72%) had isolated seizures. The risk model for seizure cluster or SE in the emergency department included Charlson Comorbidity Index scores ≥ 3 (OR: 1.60; 95% CI, 1.05-2.46; P=.030), ≥ 2 habitual antiepileptic drugs (OR: 2.29; 95% CI, 1.49-3.51; P<.001), and focal seizures (OR: 1.56; 95% CI, 1.05-2.32; P=.027). The area under the curve of the model was 0.735 (95% CI, 0.693-0.777; P=.021). Patients with seizure cluster and SE received more aggressive interventions both by prehospital emergency services (OR: 2.89; 95% CI, 1.91-4.36; P<.001) and at the emergency department (OR: 4.41; 95% CI, 2.69-7.22; P<.001).

CONCLUSIONS

This risk model may be of prognostic value in identifying adult patients at risk of presenting seizure cluster or SE in the emergency department. In our sample, these patients received more aggressive treatment than adult patients with isolated seizures before arriving at hospital, and even more so in the emergency department.

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.

Early and established status epilepticus: The impact of timing of intervention, treatment escalation and dosing on outcome

OBJECTIVE

We investigated the management and outcome of early and established status epilepticus including timing, dosing and selection of benzodiazepines along with the timing and efficacy of second line treatments.

METHODS

Retrospective single tertiary centre observational cohort study to identify all cases of SE between January 2019 and February 2022.

RESULTS

252 cases were identified. Seizures terminated spontaneously in 136 (54%) cases. 116 (46%) were given benzodiazepines, of which 29 (25%) were given at least one benzodiazepine by family/carers, and 72 (62.1%) received benzodiazepines by ambulance services. Benzodiazepines terminated seizures in 83 (71.6%) cases. The commonest benzodiazepine used was buccal midazolam (35.5%). Median time to first benzodiazepine was 14.5 (6-27) minutes. There was a positive correlation between time to first benzodiazepine and time to seizure cessation, progression to second- and third-line treatment, and respiratory complications (p<0.05). 73 (62.9%) cases received a correct benzodiazepine dose. Benzodiazepine underdosing was associated with longer seizure duration (p<0.05). 33 (28.4%) cases progressed to second-line treatment where mean time to treatment was 59.4 min (±32.3 min). The commonest second-line treatment was Levetiracetam (53.8%), followed by Phenytoin (43.6%) with SE termination in 57.5% cases. 14 (12.1%) cases progressed to third-line treatment; mean time to treatment was 60.6 min (±22.24 min). Respiratory complications occurred in 17 (6.75%) cases; none due to benzodiazepines. There were two deaths in refractory SE.

CONCLUSION

Early administration of benzodiazepines and optimal dosing is associated with a higher rate of SE termination. Levetiracetam was the most commonly used second line treatment.

Treatment of Seizure Clusters in Epilepsy: A Narrative Review on Rescue Therapies

Epilepsy is a common neurological disorder in the United States, affecting approximately 1.2% of the population. Some people with epilepsy may experience seizure clusters, which are acute repetitive seizures that differ from the person's usual seizure pattern. Seizure clusters are unpredictable, are emotionally burdensome to patients and caregivers (including care partners), and require prompt treatment to prevent progression to serious outcomes, including status epilepticus and associated morbidity (e.g., lacerations, fractures due to falls) and mortality. Rescue medications for community use can be administered to terminate a seizure cluster, and benzodiazepines are the cornerstone of rescue treatment. Despite the effectiveness of benzodiazepines and the importance of a rapid treatment approach, as many as 80% of adult patients do not use rescue medication to treat seizure clusters. This narrative review provides an update on rescue medications used for treatment of seizure clusters, with an emphasis on clinical development and study programs for diazepam rectal gel, midazolam nasal spray, and diazepam nasal spray. Results from long-term clinical trials have shown that treatments for seizure clusters are effective. Intranasal benzodiazepines provide ease of use and patient and caregiver satisfaction in pediatric and adult patients. Adverse events attributed to acute rescue treatments have been characterized as mild to moderate, and no reports of respiratory depression have been attributed to treatment in long-term safety studies. The implementation of an acute seizure action plan to facilitate optimal use of rescue medications provides an opportunity for improved management of seizure clusters, allowing those affected to resume normal daily activities more quickly.

Suboptimal Dosing of Benzodiazepines and Levetiracetam in a Cohort of Status Epilepticus Patients and Outcomes Associated with Inadequate Dosing

Background: Status epilepticus (SE) is a neurologic emergency that can result in serious morbidity and mortality. Recent studies have suggested underdosing of both benzodiazepines (BZDs) and antiseizure medications (ASM) which may result in poorer outcomes. Objectives: This study aims to determine the dose of BZDs and levetiracetam given in our emergency department for episodes of SE and determine the outcomes associated with this dosing. Methods: We conducted a retrospective cohort study of all adult patients with SE admitted to our hospital from 2017 to 2020. We collected demographic data, type of SE, dose of BZD and levetiracetam, and outcomes which included mortality and a calculated Glasgow outcome scale (GOS). We compared outcomes of patients with SE who received adequate dosing (according to practice guidelines) to those who did not. Results: 111 adult patients were included of whom 91% were seen initially in our emergency department. 75% had convulsive SE on presentation. Approximately 55% and 68% of patients did not receive an appropriate dose of BZD or levetiracetam, respectively. Inadequate dosing of BZD was associated with worse clinical outcomes based on GOS (43.6% favorable outcome vs 62.5% with adequate dosing P = .046 (95% CI, 1.01-4.60)) and inadequate dosing of both drugs was also associated with a worse GOS outcome (HR, 2.91 (95% CI, 1.05-9.67, P = .02). No difference was found in length of stay or mortality alone. Conclusion: Our study found inadequate dosing of drugs to treat SE in adults was common in our institution and was associated with worse outcomes.

Point-of-care electroencephalography enables rapid evaluation and management of non-convulsive seizures and status epilepticus in the emergency department

Objectives

To describe our institutional experience with point-of-care electroencephalography (pocEEG) and its impact on the evaluation/management of suspected non-convulsive seizures in the emergency department (ED).

Methods

We retrospectively identified 157 adults who underwent pocEEG monitoring in our community hospital ED in 1 year. We calculated the time to obtain pocEEG in the ED (door-to-EEG time) and examined the impact of pocEEG findings (categorized as seizure, highly epileptiform patterns, slowing, or normal activity) on antiseizure medication treatment.

Results

PocEEG revealed seizures (14%, n = 22), highly epileptiform patterns (22%, n = 34), slowing (44%, n = 69), and normal activity (20%, n = 32). The median door-to-EEG time (from initial ED evaluation to pocEEG monitoring) was only 1.2 hours (interquartile range 0.1-2.1) even though 55% of studies were performed after-hours (5 pm-9 am). Most patients were admitted (54% to the intensive care unit, 41% to floor). Antiseizure medication treatment occurred pre-pocEEG in 93 patients (59%) and post-pocEEG in 88 patients (56%). By reviewing the relationship between pocEEG monitoring and antiseizure medication management, we found a significant association between pocEEG findings and changes in management (P < 0.001). Treatment escalation occurred more frequently in patients with epileptiform activity (seizures or highly epileptiform patterns, 52%) than patients with non-epileptiform activity (normal or slow, 25%, P < 0.001), and avoidance of treatment escalation occurred more frequently in patients with normal or slow activity (27%) than patients with seizures or highly epileptiform patterns (2%, P < 0.001).

Conclusion

Our study, the largest to date describing the real-world use of pocEEG in emergency medicine, found that rapid EEG acquisition in the ED was feasible in a community hospital and significantly affected the management of suspected non-convulsive seizures.

Acute seizure therapies in people with epilepsy: Fact or fiction? A U.S. Perspective

Patients with epilepsy (PWE) may experience seizure emergencies including acute repetitive seizures despite chronic treatment with daily antiseizure medications. Seizures may adversely impact routine daily activities and/or healthcare utilization and may impair the quality of life of patients with epilepsy and their caregivers. Seizures often occur at home, school, or work in a community setting. Appropriate treatment that is readily accessible for patients with seizure urgencies and emergencies is essential outside the hospital setting. When determining the best acute antiseizure therapy for PWE, clinicians need to consider all of the available rescue medications and their routes of administration including the safety and efficacy profiles. Benzodiazepines are a standard of care as a rescue therapy, yet there are several misconceptions about their use and safety. Reevaluating potential misconceptions and formulating best practices are necessary to maximize usage for each available option of acute therapy. We examine common beliefs associated with traditional use of acute seizure therapies to refute or support them based on the current level of evidence in the published literature.

Understanding the Influence of Hospital Volume on Inpatient Outcomes Following Hospitalization for Status Epilepticus

BACKGROUND

Prior studies show hospital admission volume to be associated with poor outcomes following elective procedures and inpatient medical hospitalizations. However, it is unknown whether hospital volume impacts Inpatient outcomes for status epilepticus (SE) hospitalizations. In this study, we aimed to assess the impact of hospital volume on the outcome of patients with SE and related inpatient medical complications.

METHODS

The 2005 to 2013 National Inpatient Sample database was queried using International Classification of Diseases 9th Edition diagnosis code 345.3 to identify patients undergoing acute hospitalization for SE. The National Inpatient Sample hospital identifier was used as a unique facility identifier to calculate the average volume of patients with SE seen in a year. The study cohort was divided into three groups: low volume (0-7 patients with SE per year), medium volume (8-22 patients with SE per year), and high volume (> 22 patients with SE per year). Multivariate logistic regression analyses were used to assess whether medium or high hospital volume had lower rates of inpatient medical complications compared with low-volume hospitals.

RESULTS

A total of 137,410 patients with SE were included in the analysis. Most patients (n = 50,939; 37%) were treated in a low-volume hospital, 31% (n = 42,724) were treated in a medium-volume facility, and 18% (n = 25,207) were treated in a high-volume hospital. Patients undergoing treatment at medium-volume hospitals (vs. low-volume hospitals) had higher odds of pulmonary complications (odds ratio [OR] 1.18 [95% confidence interval {CI} 1.12-1.25]; p < 0.001), sepsis (OR 1.24 [95% CI 1.08-1.43] p = 0.002), and length of stay (OR 1.13 [95% CI 1.0 -1.19] p < 0.001). High-volume hospitals had significantly higher odds of urinary tract infections (OR 1.21 [95% CI 1.11-1.33] p < 0.001), pulmonary complications (OR 1.19 [95% CI 1.10-1.28], p < 0.001), thrombosis (OR 2.13 [95% CI 1.44-3.14], p < 0.001), and renal complications (OR 1.21 [95% CI 1.07-1.37], p = 0.002). In addition, high-volume hospitals had lower odds of metabolic (OR 0.81 [95% CI 0.72-0.91], p < 0.001), neurological complications (OR 0.80 [95% CI 0.69-0.93], p = 0.004), and disposition to a facility (OR 0.89 [95% CI 0.82-0.96], p < 0.001) compared with lower-volume hospitals.

CONCLUSIONS

Our study demonstrates certain associations between hospital volume and outcomes for SE hospitalizations. Further studies using more granular data about the type, severity, and duration of SE and types of treatment are warranted to better understand how hospital volume may impact care and prognosis of patients.

Optimizing Status Epilepticus Management in the Emergency Department: It's About Time

Status epilepticus (SE) is a frequent medical emergency that requires expedited treatment to avoid the ensuing high incidence of morbidity and mortality associated with prolonged seizures. Protracted seizure duration itself has the potential to result in maladaptive neuronal responses that can not only further increase seizure duration and worsen clinical outcomes but also lead to reduced responsiveness to pharmacotherapy. Benzodiazepines are consistently recommended as first-line treatment due to their rapid onset and efficacy in terminating seizures, followed by the emergent administration of an antiepileptic drug (AED). Various benzodiazepine and AED options are recommended and can be utilized in this setting, all with their own unique advantages and challenges. With time at a premium, agents should be selected that can be rapidly administered and have an advantageous pharmacokinetic profile in order to limit seizure duration and optimize outcomes. The intent of this review is to provide an outline of the importance of time-to-treatment implementation in this setting, assess the landscape of options that may provide timing advantages, and examine potential strategies for deploying expeditious therapy.

Hyperperfusion Tmax mapping for nonconvulsive status epilepticus in the acute setting: A pilot case-control study

OBJECTIVE

Nonconvulsive status epilepticus (NCSE) is misdiagnosed in >50% of cases in the emergency department. Computed tomographic perfusion (CTP) has been implemented in the hyperacute setting to detect seizure-induced hyperperfusion. However, the diagnostic value of CTP is limited by the lack of thresholds for hyperperfusion and high interrater variability. This pilot case-control study aims at identifying the diagnostic value of reverse Tmax (rTmax) in differentiating NCSE from acute ischemic stroke in the hyperacute setting.

METHODS

We enrolled patients with NCSE (Salzburg criteria-based diagnosis) and stroke cases 1:1 matched for clinical features and time of presentation. CTP standard maps (mean transit time [MTT]-cerebral blood volume-cerebral blood flow [CBF]) and rTmax maps were elaborated and rated by two experts in CTP blinded to the final diagnosis. Hyperperfusion was adjudicated for standard CTP maps as an increase in CBF and a decrease in MTT, and for rTmax as the presence of a black area on 3-, 2-, and 1-s threshold maps. Cronbach alpha was used for interrater agreement; receiver operating curve analysis was run to measure accuracy with area under the curve.

RESULTS

Overall, 34 patients were included (17 NCSE, 17 stroke; time from onset to imaging = 2 h for both groups). People with NCSE were older and more frequently had a history of epilepsy. NCSE patients had hyperperfusion on rTmax maps in 11 of 17 cases versus zero of 17 in stroke. Intra- and interrater reliability was higher for rTmax than for standard CTP maps (κ = 1 vs. κ = .6). rTmax was 82% (95%CI = 67-97%) accurate in predicting NCSE versus stroke in the hyperacute setting. Agreement between neuroimaging and electroencephalography (EEG) was limited at a hemispheric level for standard CTP maps, whereas rTMax had agreement with EEG largely reaching the sublobar level.

SIGNIFICANCE

rTmax mapping might represent a reliable tool to spot NCSE-induced hyperperfusion with a threshold-based reproducible approach. Further studies are needed for validation and implementation in the differential diagnosis of focal neurological deficit in the hyperacute setting.

An aqueous extract of Syzygium cumini protects against kainate-induced status epilepticus and amnesia: evidence for antioxidant and anti-inflammatory intervention

Temporal lobe epilepsy is the most common drug-resistant epilepsy. To cure epilepsy, drugs must target the mechanisms at the origin of seizures. Thus, the present investigation aimed to evaluate the antiepileptic- and anti-amnesic-like effects of an aqueous extract of Syzygium cumini against kainate-induced status epilepticus in mice, and possible mechanisms of action. Mice were divided into 7 groups and treated as follows: normal group or kainate group received po distilled water (10 mL/kg), four test groups received Syzygium cumini (28.8, 72, 144, and 288 mg/kg, po), and the positive control group treated intraperitoneally (ip) with sodium valproate (300 mg/kg). An extra group of normal mice was treated with piracetam (200 mg/kg, po). Treatments were administered 60 min before the induction of status epilepticus with kainate (15 mg/kg, ip), and continued daily throughout behavioral testing. Twenty-four hours after the induction, T-maze and Morris water maze tasks were successively performed. The animals were then sacrificed and some markers of oxidative stress and neuroinflammation were estimated in the hippocampus. The extract significantly prevented status epilepticus and mortality. In the T-maze, the aqueous extract markedly increased the time spent and the number of entries in the discriminated arm. In the Morris water maze, the extract significantly increased the time spent in the target quadrant during the retention phase. Furthermore, the aqueous extract induced a significant reduction of oxidative stress and neuroinflammation. These results suggest that the aqueous extract of Syzygium cumini has antiepileptic- and anti-amnesic-like effects, likely mediated in part by antioxidant and anti-inflammatory activities.

Timing matters: there are significant differences in short-term outcomes between two time points of status epilepticus

Background

In 2015, the International League Against Epilepsy proposed a new conceptual definition of status epilepticus (SE) with two operational dimensions (t1 and t2) to guide emergency treatment. The purpose of this study was to compare clinical characteristics and prognoses of patients at these two different time points.

Methods

We conducted a prospective observational cohort study of consecutive adults diagnosed with SE. In case of convulsive SE, t1 is 5 min and t2 is 30 min, whereas in case of focal SE with impaired consciousness, t1 is 10 min, t2 is 60 min. Data on clinical characteristics, including age, gender, history of prior seizures, neuroimaging, semiology, duration, and etiology of SE, were collected. The primary outcome was mortality, with seizure recurrence as a secondary measure, and functional status as tertiary outcome of enrolled patients at 3 months after SE onset.

Results

We screened one hundred patients with SE, with a median age of 66 years and 61% were male. Fifty-six (56.0%) patients reached t1 of SE, while 44 (44.0%) reached t2 of SE. Convulsive SE (52.0%, n = 52) was more common than focal SE with impaired consciousness (48.0%, n = 48). Status epilepticus secondary to an acute symptomatic process was the most common (50%, n = 50). Patients meeting t2 of SE demonstrated a remarkably increased risk of mortality (unadjusted analysis-RR 3.606, 95%CI 1.552–8.376, p = 0.003; adjusted analysis-RR 2.924, 95%CI 1.221–7.003, p = 0.016) and unfavorable functional status (unadjusted analysis-RR 1.803, 95%CI 1.280–2.539, p = 0.001; adjusted analysis-RR 1.664, 95%CI 1.184–2.340, p = 0.003) at 3 months compared to those who only reached t1 of SE. Patients reaching t2 of SE were more likely to experience seizure recurrence, however, there was no significant difference between the two cohorts.

Conclusions

Our study provides strong support for the new definition of SE. Patients meeting t2 of SE tend to have a remarkably increased risk of mortality and unfavorable functional outcomes compared to those who only reached t1 of SE. Furthermore, patients were likely to experience seizure recurrence after undergoing an episode of SE. Physicians must be educated about prompt recognition and appropriate management of SE.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12883-022-02868-y.

Evaluation of phenytoin loading doses in overweight patients using actual versus adjusted body weight

BACKGROUND AND OBJECTIVES

The appropriate loading dose strategy for phenytoin/fosphenytoin in overweight patients is unknown. A small pharmacokinetic study indicated that overweight patients have a higher volume of distribution and potentially would benefit from using adjusted body weight (AdjBW) instead of actual body weight (ABW) to calculate the loading dose. The purpose of this study was to determine the optimal loading dose strategy of phenytoin in patients whose ABW is greater than 120% of their ideal body weight (IBW) using either ABW or AdjBW for calculation of the loading dose.

METHODS

This was a single center, retrospective study which included patients who received a loading dose of phenytoin of at least 10 mg/kg based on ABW, had a phenytoin level drawn <6 h after the end of the dose, and weighed ≥120% of their IBW. Patients were excluded if they received intramuscular phenytoin or fosphenytoin or were prescribed phenytoin prior to the loading dose. Patients were divided into two groups, those who were dosed using their AdjBW versus those dosed using ABW. The primary outcome was achievement of therapeutic phenytoin level of 10-20 mcg/mL. Secondary outcomes included achievement of a subtherapeutic or supratherapeutic level.

RESULTS

A total of 195 patients (128 in AdjBW group and 67 in ABW group) met criteria for inclusion. Patients in the AdjBW group weighed more (96.2 kg vs. 91.2 kg, p = 0.04) and received a lower dose in milligrams (1364 vs. 1760, p < 0.0001) and in mg/kg of ABW (14.2 vs. 19.3, p < 0.0001). The primary outcome was achieved in 74% of patients in the AdjBW group and 57% of patients in the ABW group (p = 0.02). Patients in the ABW group were more likely to have a supratherapeutic level (43% vs. 22%, p = 0.003), although adverse reactions did not differ between the groups.

DISCUSSION

Patients weighing >120% of their IBW (average body mass index 33.5 kg/m²) who received a 20 mg/kg loading dose based on AdjBW were more likely to achieve a therapeutic phenytoin concentration compared to those dosed based on ABW. Further research is needed to correlate this finding with clinical outcomes, such as resolution of status epilepticus.

Refractory and Super-Refractory Status Epilepticus in Nerve Agent-Poisoned Rats Following Application of Standard Clinical Treatment Guidelines

Nerve agents (NAs) induce a severe cholinergic crisis that can lead to status epilepticus (SE). Current guidelines for treatment of NA-induced SE only include prehospital benzodiazepines, which may not fully resolve this life-threatening condition. This study examined the efficacy of general clinical protocols for treatment of SE in the specific context of NA poisoning in adult male rats. Treatment with both intramuscular and intravenous benzodiazepines was entirely insufficient to control SE. Second line intervention with valproate (VPA) initially terminated SE in 35% of rats, but seizures always returned. Phenobarbital (PHB) was more effective, with SE terminating in 56% of rats and 19% of rats remaining seizure-free for at least 24 h. The majority of rats demonstrated refractory SE (RSE) and required treatment with a continuous third-line anesthetic. Both ketamine (KET) and propofol (PRO) led to high levels of mortality, and nearly all rats on these therapies had breakthrough seizure activity, demonstrating super-refractory SE (SRSE). For the small subset of rats in which SE was fully resolved, significant improvements over controls were observed in recovery metrics, behavioral assays, and brain pathology. Together these data suggest that NA-induced SE is particularly severe, but aggressive treatment in the intensive care setting can lead to positive functional outcomes for casualties.

Benzodiazepine administration patterns before escalation to second-line medications in pediatric refractory convulsive status epilepticus

Objective

This study was undertaken to evaluate benzodiazepine (BZD) administration patterns before transitioning to non‐BZD antiseizure medication (ASM) in pediatric patients with refractory convulsive status epilepticus (rSE).

Methods

This retrospective multicenter study in the United States and Canada used prospectively collected observational data from children admitted with rSE between 2011 and 2020. Outcome variables were the number of BZDs given before the first non‐BZD ASM, and the number of BZDs administered after 30 and 45 min from seizure onset and before escalating to non‐BZD ASM.

Results

We included 293 patients with a median (interquartile range) age of 3.8 (1.3–9.3) years. Thirty‐six percent received more than two BZDs before escalating, and the later the treatment initiation was after seizure onset, the less likely patients were to receive multiple BZD doses before transitioning (incidence rate ratio [IRR] = .998, 95% confidence interval [CI] = .997–.999 per minute, p = .01). Patients received BZDs beyond 30 and 45 min in 57.3% and 44.0% of cases, respectively. Patients with out‐of‐hospital seizure onset were more likely to receive more doses of BZDs beyond 30 min (IRR = 2.43, 95% CI = 1.73–3.46, p < .0001) and beyond 45 min (IRR = 3.75, 95% CI = 2.40–6.03, p < .0001) compared to patients with in‐hospital seizure onset. Intermittent SE was a risk factor for more BZDs administered beyond 45 min compared to continuous SE (IRR = 1.44, 95% CI = 1.01–2.06, p = .04). Forty‐seven percent of patients (n = 94) with out‐of‐hospital onset did not receive treatment before hospital arrival. Among patients with out‐of‐hospital onset who received at least two BZDs before hospital arrival (n = 54), 48.1% received additional BZDs at hospital arrival.

Significance

Failure to escalate from BZDs to non‐BZD ASMs occurs mainly in out‐of‐hospital rSE onset. Delays in the implementation of medical guidelines may be reduced by initiating treatment before hospital arrival and facilitating a transition to non‐BZD ASMs after two BZD doses during handoffs between prehospital and in‐hospital settings.

Risk model of seizure cluster or status epilepticus and intervention in the emergency department

OBJECTIVES

To identify possible predictors of seizure cluster or status epilepticus (SE) and to evaluate whether these patients receive greater interventions in emergency departments.

METHODOLOGY

We conducted a secondary analysis of the ACESUR Registry, a multipurpose, observational, prospective, multicentre registry of adult patients with seizures from 18 emergency departments. Clinical and care-related variables were collected. We identified risk factors and risk models for seizure cluster or SE and assessed the effect of interventions by prehospital emergency services and the hospital emergency department.

RESULTS

We identified a total of 186 (28%) patients from the ACESUR registry with seizure cluster (126 [19%]) or SE (60 [9%]); the remaining 478 patients (72%) had isolated seizures. The risk model for seizure cluster or SE in the emergency department included Charlson Comorbidity Index scores≥3 (OR: 1.60; 95% CI, 1.05-2.46; P=.030), ≥2 habitual antiepileptic drugs (OR: 2.29; 95% CI, 1.49-3.51; P<.001), and focal seizures (OR: 1.56; 95% CI, 1.05-2.32; P=.027). The area under the curve of the model was 0.735 (95% CI, 0.693-0.777; P=.021). Patients with seizure cluster and SE received more aggressive interventions both by prehospital emergency services (OR: 2.89; 95% CI, 1.91-4.36; P<.001) and at the emergency department (OR: 4.41; 95% CI, 2.69-7.22; P<.001).

CONCLUSIONS

This risk model may be of prognostic value in identifying adult patients at risk of presenting seizure cluster or SE in the emergency department. In our sample, these patients received more aggressive treatment than adult patients with isolated seizures before arriving at hospital, and even more so in the emergency department.

Dietary Management of Children With Super-Refractory Status Epilepticus: A Systematic Review and Experience in a Single UK Tertiary Centre

Ketogenic diet therapies (KDT) are high-fat, low carbohydrate diets used as an effective treatment option for drug-resistant epilepsy. There is limited research on the efficacy of KDT for super-refractory status epilepticus (SRSE). We systematically review evidence for use of KDT in children with SRSE and present a single UK tertiary centre's experience. Thirty one articles were included, of which 24 were “medium” or “low” quality. One hundred and forty seven children with SRSE started KDT, of which 141 (96%) achieved ketosis. KDT was started mean 5.3 days (range 1–420) after status epilepticus (SE) started. SRSE resolved in 85/141 (60%) children after mean 6.3 days (range 0–19) post SE onset, but it is unclear whether further treatments were initiated post-KDT. 13/141 (9%) children died. Response to KDT was more likely when initiated earlier (p = 0.03) and in females (p = 0.01). Adverse side effects were reported in 48/141 (34%), mostly gastrointestinal; potentially serious adverse effects occurred in ≤4%. Eight children with SRSE, all diagnosed with febrile infection-related epilepsy syndrome, were treated with KDT at Great Ormond Street Hospital for Children. KDT was initiated enterally at mean day 13.6+/− 5.1 of admission. Seven of 8 (88%) children reported adverse side effects, which were potentially serious in 4/8 (50%), including metabolic acidosis, hypoglycaemia and raised amylase. SE ceased in 6/8 (75%) children after mean 25+/− 9.4 days post onset, but other treatments were often started concomitantly and all children started other treatments post-KDT. Two of 8 (25%) children died during admission and another died post-admission. Four of the remaining 5 children continue to have drug-resistant seizures, one of whom remains on KDT; seizure burden was unknown for one child. Our findings indicate that KDT is possible and safe in children with SRSE. Cessation of SRSE may occur in almost two-thirds of children initiated with KDT, but a causal effect is difficult to determine due to concomitant treatments, treatments started post-KDT and the variable length of time post-KDT onset when SRSE cessation occurs. Given that serious adverse side effects seem rare and response rates are (cautiously) favorable, KDT should be considered as an early treatment option in this group.

Factors associated with resistance to benzodiazepines in status epilepticus

OBJECTIVE

To investigate factors related to benzodiazepine (BZD) resistance in status epilepticus (SE) with a focus on their relationship with the etiology of the episode.

METHODS

All SE cases in patients aged >16 years treated with BZDs were prospectively collected in our center from February 2011 to April 2019. The registry included demographics, SE type and etiology, the timing and duration of BZD administration, and the outcome. In total, 371 episodes were analyzed.

RESULTS

Median age at SE onset was 61.3 years; the most frequent etiology was acute symptomatic (55.8%). SE with prominent motor symptoms occurred in 63.3%. Median time to BZD administration was 2 h. We studied the correlation between two-time variables: time from SE onset to BZD administration and time from BZD administration to resolution of SE (response); we observed that timely administration correlated with a faster response in patients with prominent motor symptoms (p = 0.017), SE due to a chronic structural cerebral lesion (p = 0.004), and patients with a history of seizures (p = 0.013). In these subgroups (prominent motor symptoms or chronic structural lesion) BZD administration within the first 4.5 h was highly associated with shorter post-BZD SE duration (p < 0.001).

SIGNIFICANCE

The relationship between prompt BZD administration and subsequent duration of SE was found to depend to some extent on the etiology of the episode: patients with chronic structural lesions and those with previous epilepsy responded faster to BZDs. Semiology may have also its impact, as the presence of prominent motor symptoms showed also a faster response.

Non-COVID Neurological Emergencies: A Silent Killer Going Unnoticed during COVID-19 Pandemic

Objective  This study assesses the impact of coronavirus disease 2019 (COVID-19) on the pattern of neurological emergencies reaching a tertiary care center.

Materials and Methods  This is a retrospective and single center study involving 295 patients with neurological emergencies mainly including acute stroke, status epilepticus (SE), and tubercular meningitis visiting emergency department (ED) from January 1 to April 30, 2020 and divided into pre- and during lockdown, the latter starting from March 25 onward. The primary outcome was number of neurological emergencies visiting ED per week in both periods. Secondary outcomes included disease severity at admission, need for mechanical ventilation (MV), delay in hospitalization, in-hospital mortality, and reasons for poor compliance to ongoing treatment multivariate binary logistic regression was used to find independent predictors of in-hospital mortality which included variables with p <0.1 on univariate analysis. Structural break in the time series analysis was done by using Chow test.

Results  There was 53.8% reduction in number of neurological emergencies visiting ED during lockdown (22.1 visits vs. 10.2 visits per week, p = 0.001), significantly affecting rural population ( p = 0.004). Presenting patients had comparatively severe illness with increased requirement of MV ( p < 0.001) and significant delay in hospitalization during lockdown ( p < 0.001). Poor compliance to ongoing therapy increased from 34.4% in pre-lockdown to 64.7% patients during lockdown ( p < 0.001), mostly due to nonavailability of drugs ( p < 0.001). Overall, 35 deaths were recorded, with 20 (8.2%) in pre-lockdown and 15 (29.4%) during lockdown ( p = 0.001). Lockdown, nonavailability of local health care, delay in hospitalization, severity at admission, and need for MV emerged as independent predictors of poor outcome in stroke and delay in hospitalization in SE.

Conclusion  COVID-19 pandemic and associated lockdown resulted in marked decline in non-COVID neurological emergencies reporting to ED, with more severe presentations and significant delay from onset of symptoms to hospitalization.

Assessment of benzodiazepine dosing strategies for the management of status epilepticus in the emergency department

PURPOSE

Although guidelines recommend specific benzodiazepine doses for the treatment of generalized convulsive status epilepticus (GCSE), underdosing appears to be common. The purpose of this investigation was to assess benzodiazepine dosing strategies for the initial management of GCSE in patients presenting to the Emergency Department (ED).

METHODS

This was a retrospective review of adult patients who received benzodiazepines in the ED for treatment of GCSE. Characteristics of those achieving seizure cessation following initial benzodiazepine therapy were assessed.

RESULTS

222 patients presented to the ED and received 403 doses of benzodiazepines, of which 1.5% conformed with recommendations. First-line therapy was successful in 86.8% of patients with an average dose of 1.6 mg (0.02 mg/kg). No difference in dosing was noted between those experiencing early cessation and those that did not (p = 0.132). Patients experiencing early cessation were significantly less likely to receive further doses, be intubated, or be admitted to the intensive care unit (ICU) or hospital (p < 0.05 for all comparisons). Those that received early antiepileptic drug therapy were significantly less likely to receive additional benzodiazepine doses, be intubated, or be admitted to the ICU or hospital (p < 0.05 for all comparisons).

CONCLUSIONS

According to guideline recommendations, there was consistent underdosing of benzodiazepines noted in both prehospital and ED settings. Early seizure cessation and the early receipt of an antiepileptic drug were found to be associated with multiple significant clinical outcomes. Future investigations should explore optimal dosing strategies for benzodiazepines as well as the impact of early antiepileptic drug administration.

Patterns of benzodiazepine underdosing in the Established Status Epilepticus Treatment Trial

OBJECTIVE

This study was undertaken to describe patterns of benzodiazepine use as first-line treatment of status epilepticus (SE) and test the association of benzodiazepine doses with response to second-line agents in patients enrolled in the Established Status Epilepticus Treatment Trial (ESETT).

METHODS

Patients refractory to an adequate dose of benzodiazepines for the treatment of SE were enrolled in ESETT. Choice of benzodiazepine, doses given prior to administration of second-line agent, route of administration, setting, and patient weight were characterized. These were compared with guideline-recommended dosing. Logistic regression was used to determine the association of the first dose of benzodiazepine and the cumulative benzodiazepine dose with the response to second-line agent.

RESULTS

Four hundred sixty patients were administered 1170 doses of benzodiazepines (669 lorazepam, 398 midazolam, 103 diazepam). Lorazepam was most frequently administered intravenously in the emergency department, midazolam intramuscularly or intravenously by the emergency medical services personnel, and diazepam rectally prior to ambulance arrival. The first dose of the first benzodiazepine (N = 460) was lower than guideline recommendations in 76% of midazolam administrations and 81% of lorazepam administrations. Among all administrations, >85% of midazolam and >76% of lorazepam administrations were lower than recommended. Higher first or cumulative benzodiazepine doses were not associated with better outcomes or clinical seizure cessation in response to second-line medications in these benzodiazepine-refractory seizures.

SIGNIFICANCE

Benzodiazepines as first-line treatment of SE, particularly midazolam and lorazepam, are frequently underdosed throughout the United States. This broad and generalizable cohort confirms prior single site reports that underdosing is both pervasive and difficult to remediate. (ESETT ClinicalTrials.gov identifier: NCT01960075.).

Delayed Adjunctive Treatment of Organophosphate-Induced Status Epilepticus in Rats with Phenobarbital, Memantine, or Dexmedetomidine

Organophosphate (OP) exposure induces status epilepticus (SE), a medical emergency with high morbidity and mortality. Current standard medical countermeasures lose efficacy with time so that treatment delays, in the range of tens of minutes, result in increasingly poor outcomes. As part of the Countermeasures Against Chemical Threats Neurotherapeutics Screening Program, we previously developed a realistic model of delayed treatment of OP-induced SE using the OP diisopropyl fluorophosphate (DFP) to screen compounds for efficacy in the termination of SE and elimination of neuronal death. Male rats were implanted for electroencephalogram (EEG) recordings 7 days prior to experimentation. Rats were then exposed to DFP, and SE was induced for 60 minutes and then treated with midazolam (MDZ) plus one of three antiseizure drugs (ASDs)-phenobarbital (PHB), memantine (MEM), or dexmedetomidine (DMT)-in conjunction with antidotes. EEG was recorded for 24 hours, and brains were stained with Fluoro-Jade B for quantification of degenerating neurons. We found that PHB + MDZ induced a prolonged suppression of SE and reduced neuronal death. MEM + MDZ treatment exacerbated SE and increased mortality; however, surviving rats had fewer degenerating neurons. DMT + MDZ significantly suppressed SE with only a minimal reduction in neuronal death. These data demonstrate that delayed treatment of OP-induced SE with other ASDs, when added to MDZ, can achieve greater seizure suppression with additional reduction in degenerating neurons throughout the brain compared with MDZ alone. The effect of a drug on the severity of seizure activity did not necessarily determine the drug's effect on neuronal death under these conditions. SIGNIFICANCE STATEMENT: This study assesses the relative effectiveness of three different delayed-treatment regimens for the control of organophosphate-induced status epilepticus and reduction of subsequent neuronal death. The data demonstrate the potential for highly effective therapies despite significant treatment delay and a potential disconnect between seizure severity and neuronal death.

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.

Head mounted telemetry system for seizures monitoring and sleep scoring on non-human primate

Radio telemetry systems are a useful way to continuously monitor broad electrical neuronal activity in behaving animals. It can also be used to study sleep disturbances or monitor seizure activity. Many different telemeter styles are available, but the more versatile and cost-efficient ones are the head mounted systems. They permit long-term recordings and allow more flexibility in the recordings. However, there are currently no such system available for non-human primate (NHP). In fact, the choices for NHP telemetry solutions are very limited. Here, we present a chronically implantable 3D printed chamber specifically designed to accommodate a rodent head-mounted system (RodentPACK) onto a NHP's head. We recorded EEG signal for more than a year, confirmed quality of the signal, and the ability to use the data to monitor sleep activity. We also used two of our epileptic animals to validate the embedded alarm system for real time seizure monitoring. While initially not designed for NHP, but with a minimum number of adaptions, this telemeter is in fact perfectly suitable for NHP experiments. Since early medical intervention during seizures is critical to avoid status epilepticus and to save the animal's life, real time seizures monitoring is becoming a safety requirement in many NHP studies. This method refines the current seizure monitoring methods for NHP and creates a flexible telemetry solution.

Ketogenic diet treatment of children in the intensive care unit: Safety, tolerability, and effectiveness

PURPOSE

The ketogenic diet (KD) is initiated emergently in the intensive care unit (ICU) for patients with super refractory status epilepticus (SRSE) and epileptic encephalopathies (EE). However, few data are available regarding safety, effectiveness, and long-term outcomes.

METHODS

We performed a retrospective cohort study of consecutive patients with KD initiated in the ICU from 2010 to 2018 for SRSE and EE. We characterized time to ketosis, adverse effects, and seizure outcomes. Responders were defined as having ≥50 % reduction in seizure frequency compared to prior to KD initiation.

RESULTS

We identified 29 patients. KD was initiated for SRSE in 12 patients, EE in 8 patients, and EE with SRSE in 9 patients. KD was initiated after a median of 9 days. Ketosis was achieved 2 days faster in fasted patients (p < 0.0001). All patients had at least 1 KD-related adverse effect, most often hypoglycemia, constipation, or acidosis. There was ≥50 % reduction in seizure frequency compared to prior to KD initiation by 1 week in 17/28 patients, seizure-freedom by 2 weeks in 7/28 patients, and weaned off anesthetics in 11/17 patients. All KD-responders at 1 month had continued response at 6 months. Mortality at 1 year was 24 %. There was no difference in KD response or mortality between KD indication groups.

CONCLUSION

Emergent KD initiation in the ICU is feasible, safe, and often effective for SRSE and EE. Expected adverse effects were common but treatable. Morbidity and mortality in this group was high. A ≥ 50 % reduction in seizure is achieved in most responders by 1-2 weeks.

Association of guideline publication and delays to treatment in pediatric status epilepticus

Objective

To determine whether publication of evidence on delays in time to treatment shortens time to treatment in pediatric refractory convulsive status epilepticus (rSE), we compared time to treatment before (2011–2014) and after (2015–2019) publication of evidence of delays in treatment of rSE in the Pediatric Status Epilepticus Research Group (pSERG) as assessed by patient interviews and record review.

Methods

We performed a retrospective analysis of a prospectively collected dataset from June 2011 to September 2019 on pediatric patients (1 month–21 years of age) with rSE.

Results

We studied 328 patients (56% male) with median (25th–75th percentile [p₂₅–p₇₅]) age of 3.8 (1.3–9.4) years. There were no differences in the median (p₂₅–p₇₅) time to first benzodiazepine (BZD) (20 [5–52.5] vs 15 [5–38] minutes, p = 0.3919), time to first non-BZD antiseizure medication (68 [34.5–163.5] vs 65 [33–142] minutes, p = 0.7328), and time to first continuous infusion (186 [124.2–571] vs 160 [89.5–495] minutes, p = 0.2236). Among 157 patients with out-of-hospital onset whose time to hospital arrival was available, the proportion who received at least 1 BZD before hospital arrival increased after publication of evidence of delays (41 of 81 [50.6%] vs 57 of 76 [75%], p = 0.0018), and the odds ratio (OR) was also increased in multivariable logistic regression (OR 4.35 [95% confidence interval 1.96–10.3], p = 0.0005).

Conclusion

Publication of evidence on delays in time to treatment was not associated with improvements in time to treatment of rSE, although it was associated with an increase in the proportion of patients who received at least 1 BZD before hospital arrival.

Excitatory GABAergic signalling is associated with benzodiazepine resistance in status epilepticus

Status epilepticus is defined as a state of unrelenting seizure activity. Generalized convulsive status epilepticus is associated with a rapidly rising mortality rate, and thus constitutes a medical emergency. Benzodiazepines, which act as positive modulators of chloride (Cl-) permeable GABAA receptors, are indicated as first-line treatment, but this is ineffective in many cases. We found that 48% of children presenting with status epilepticus were unresponsive to benzodiazepine treatment, and critically, that the duration of status epilepticus at the time of treatment is an important predictor of non-responsiveness. We therefore investigated the cellular mechanisms that underlie acquired benzodiazepine resistance, using rodent organotypic and acute brain slices. Removing Mg2+ ions leads to an evolving pattern of epileptiform activity, and eventually to a persistent state of repetitive discharges that strongly resembles clinical EEG recordings of status epilepticus. We found that diazepam loses its antiseizure efficacy and conversely exacerbates epileptiform activity during this stage of status epilepticus-like activity. Interestingly, a low concentration of the barbiturate phenobarbital had a similar exacerbating effect on status epilepticus-like activity, while a high concentration of phenobarbital was effective at reducing or preventing epileptiform discharges. We then show that the persistent status epilepticus-like activity is associated with a reduction in GABAA receptor conductance and Cl- extrusion capability. We explored the effect on intraneuronal Cl- using both gramicidin, perforated-patch clamp recordings and Cl- imaging. This showed that during status epilepticus-like activity, reduced Cl- extrusion capacity was further exacerbated by activity-dependent Cl- loading, resulting in a persistently high intraneuronal Cl-. Consistent with these results, we found that optogenetic stimulation of GABAergic interneurons in the status epilepticus-like state, actually enhanced epileptiform activity in a GABAAR dependent manner. Together our findings describe a novel potential mechanism underlying benzodiazepine-resistant status epilepticus, with relevance to how this life-threatening condition should be managed in the clinic.

Comparison of intranasal versus intravenous midazolam for management of status epilepticus in dogs: A multi-center randomized parallel group clinical study

Background

The intranasal (IN) route for rapid drug administration in patients with brain disorders, including status epilepticus, has been investigated. Status epilepticus is an emergency, and the IN route offers a valuable alternative to other routes, especially when these fail.

Objectives

To compare IN versus IV midazolam (MDZ) at the same dosage (0.2 mg/kg) for controlling status epilepticus in dogs.

Animals

Client‐owned dogs (n = 44) with idiopathic epilepsy, structural epilepsy, or epilepsy of unknown origin manifesting as status epilepticus.

Methods

Randomized parallel group clinical trial. Patients were randomly allocated to the IN‐MDZ (n = 21) or IV‐MDZ (n = 23) group. Number of successfully treated cases (defined as seizure cessation within 5 minutes and lasting for ≥10 minutes), seizure cessation time, and adverse effects were recorded. Comparisons were performed using the Fisher's exact and Wilcoxon rank sum tests with statistical significance set at α < .05.

Results

IN‐MDZ and IV‐MDZ successfully stopped status epilepticus in 76% and 61% of cases, respectively (P = .34). The median seizure cessation time was 33 and 64 seconds for IN‐MDZ and IV‐MDZ, respectively (P = .63). When the time to place an IV catheter was taken into account, IN‐MDZ (100 seconds) was superior (P = .04) to IV‐MDZ (270 seconds). Sedation and ataxia were seen in 88% and 79% of the dogs treated with IN‐MDZ and IV‐MDZ, respectively.

Conclusions and Clinical Importance

Both routes are quick, safe, and effective for controlling status epilepticus. However, the IN route demonstrated superiority when the time needed to place an IV catheter was taken into account.

Validating a model of benzodiazepine refractory nerve agent-induced status epilepticus by evaluating the anticonvulsant and neuroprotective effects of scopolamine, memantine, and phenobarbital

INTRODUCTION

Organophosphorus nerve agents (OPNAs) irreversibly block acetylcholinesterase activity, resulting in accumulation of excess acetylcholine at neural synapses, which can lead to a state of prolonged seizures known as status epilepticus (SE). Benzodiazepines, the current standard of care for SE, become less effective as latency to treatment increases. In a mass civilian OPNA exposure, concurrent trauma and limited resources would likely cause a delay in first response time. To address this issue, we have developed a rat model to test novel anticonvulsant/ neuroprotectant adjuncts at delayed time points.

METHODS

For model development, adult male rats with cortical electroencephalographic (EEG) electrodes were exposed to soman and administered saline along with atropine, 2-PAM, and midazolam 5, 20, or 40 min after SE onset. We validated our model using three drugs: scopolamine, memantine, and phenobarbital. Using the same procedure outlined above, rats were given atropine, 2-PAM, midazolam and test treatment 20 min after SE onset.

RESULTS

Using gamma power, delta power, and spike rate to quantify EEG activity, we found that scopolamine was effective, memantine was minimally effective, and phenobarbital had a delayed effect on terminating SE. Fluoro-Jade B staining was used to assess neuroprotection in five brain regions. Each treatment provided significant protection compared to saline + midazolam in at least two brain regions.

DISCUSSION

Because our data agree with previously published studies on the efficacy of these compounds, we conclude that this model is a valid way to test novel anticonvulsants/ neuroprotectants for controlling benzodiazepine-resistant OPNA-induced SE and subsequent neuropathology.