Therapeutic coma for status epilepticus: Differing practices in a prospective multicenter study

Status epilepticus in the ICU

Status epilepticus (SE) is a common medical emergency associated with significant morbidity and mortality. Management that follows published guidelines is best suited to improve outcomes, with the most severe cases frequently being managed in the intensive care unit (ICU). Diagnosis of convulsive SE can be made without electroencephalography (EEG), but EEG is required to reliably diagnose nonconvulsive SE. Rapidly narrowing down underlying causes for SE is crucial, as this may guide additional management steps. Causes may range from underlying epilepsy to acute brain injuries such as trauma, cardiac arrest, stroke, and infections. Initial management consists of rapid administration of benzodiazepines and one of the following non-sedating intravenous antiseizure medications (ASM): (fos-)phenytoin, levetiracetam, or valproate; other ASM are increasingly used, such as lacosamide or brivaracetam. SE that continues despite these medications is called refractory, and most commonly treated with continuous infusions of midazolam or propofol. Alternatives include further non-sedating ASM and non-pharmacologic approaches. SE that reemerges after weaning or continues despite management with propofol or midazolam is labeled super-refractory SE. At this step, management may include non-sedating or sedating compounds including ketamine and barbiturates. Continuous video EEG is necessary for the management of refractory and super-refractory SE, as these are almost always nonconvulsive. If possible, management of the underlying cause of seizures is crucial particularly for patients with autoimmune encephalitis. Short-term mortality ranges from 10 to 15% after SE and is primarily related to increasing age, underlying etiology, and medical comorbidities. Refractoriness of treatment is clearly related to outcome with mortality rising from 10% in responsive cases, to 25% in refractory, and nearly 40% in super-refractory 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.

Duration of constant rate infusion with diazepam or propofol for canine cluster seizures and status epilepticus

Introduction

Constant rate infusion (CRI) of benzodiazepines or propofol (PPF) is a therapeutic option for cluster seizures (CS) and status epilepticus (SE) in canine patients non-responding to first-line benzodiazepines or non-anesthetics. However, specific indications for optimal duration of CRI are lacking. The aim of this study was to determine the effect of duration of anesthetic CRI on outcome and length of hospital stay in dogs with refractory seizure activity of different etiology.

Study design

Open-label non-randomized clinical trial.

Materials and methods

Seventy-three client-owned dogs were enrolled. Two groups [experimental (EXP) vs. control (CTRL)] were compared. The EXP group received diazepam (DZP) or PPF CRI for 12 h (±1 h) and the CTRL group received DZP or PPF CRI for 24 h (±1 h) in addition to a standardized emergency treatment protocol identical for both study groups. The historical control group was made up of a population of dogs already reported in a previously published paper by the same authors. Favorable outcome was defined as seizure cessation after CRI, no seizure recurrence, and clinical recovery. Poor outcome was defined as seizure recurrence, death in hospital or no return to acceptable clinical baseline. Univariate statistical analysis was performed.

Results

The study sample was 73 dogs: 45 (62%) received DZP CRI and 28 (38%) received PPF CRI. The EXP group was 39 dogs (25 DZP CRI and 14 PPF CRI) and the CTRL group 34 dogs (20 DZP CRI and 14 PPF CRI). We found no statistically significant difference in outcomes between the groups. The median length of stay was 56 h (IQR, 40-78) for the ALL EXP group and 58.5 h (IQR, 48-74.5) for the ALL CTRL group (p = 0.8).

Conclusion

Even though a shorter DZP or PPF CRI duration was not associated with a worse outcome, the study failed to identify a clear superiority of shorter CRI duration on outcome or length of hospital stay in dogs with refractory seizure activity of different etiology.

Midazolam, Ketamine, and Propofol: While We Slept, Others Worked on Anesthetizing Infusions for Refractory Status Epilepticus

Management of Refractory Status Epilepticus: An International Cohort Study (MORSE CODe) Analysis of Patients Managed in the ICU Chiu WT, Campozano V, Schiefecker A, Rodriguez DR, Ferreira D, Headlee A, Zeidan S, Grinea A, Huang YH, Doyle K, Shen Q, Gómez D, Hocker SE, Rohaut B, Sonneville R, Hong C-T, Demeret S, Kurtz P, Maldonado N, Helbok R, Fernandez T, Claassen J. Neurology . 2022;99(11):e1191-e1201. doi:10.1212/WNL.0000000000200818 Background and Objectives: Status epilepticus that continues after the initial benzodiazepine and a second anticonvulsant medication is known as refractory status epilepticus (RSE). Management is highly variable because adequately powered clinical trials are missing. We aimed to determine whether propofol and midazolam were equally effective in controlling RSE in the intensive care unit, focusing on management in resource-limited settings. Methods: Patients with RSE treated with midazolam or propofol between January 2015 and December 2018 were retrospectively identified among 9 centers across 4 continents from upper-middle-income economies in Latin America and high-income economies in North America, Europe, and Asia. Demographics, Status Epilepticus Severity Score, etiology, treatment details, and discharge modified Rankin Scale (mRS) were collected. The primary outcome measure was good functional outcome defined as a mRS score of 0-2 at hospital discharge. Results: Three hundred eighty-seven episodes of RSE (386 patients) were included, with 162 (42%) from upper-middle-income and 225 (58%) from high-income economies. Three hundred six (79%) had acute and 79 (21%) remote etiologies. Initial RSE management included midazolam in 266 (69%) and propofol in 121 episodes (31%). Seventy episodes (26%) that were initially treated with midazolam and 42 (35%) with propofol required the addition of a second anesthetic to treat RSE. Baseline characteristics and outcomes of patients treated with midazolam or propofol were similar. Breakthrough (odds ratio [OR] 1.6, 95% CI 1.3-2.0) and withdrawal seizures (OR 2.0, 95% CI 1.7-2.5) were associated with an increased number of days requiring continuous intravenous anticonvulsant medications (cIV-ACMs). Prolonged EEG monitoring was associated with fewer days of cIV-ACMs (1-24 hours OR 0.5, 95% CI 0.2-0.9, and >24 hours OR 0.7, 95% CI 0.5-1.0; reference EEG <1 hour). This association was seen in both, high-income and upper-middle-income economies, but was particularly prominent in high-income countries. One hundred ten patients (28%) were dead, and 80 (21%) had good functional outcomes at hospital discharge. Discussion: Outcomes of patients with RSE managed in the intensive care unit with propofol or midazolam infusions are comparable. Prolonged EEG monitoring may allow physicians to decrease the duration of anesthetic infusions safely, but this will depend on the implementation of RSE management protocols. Goal-directed management approaches including EEG targets may hold promise for patients with RSE. Ketamine for Management of Neonatal and Pediatric Refractory Status Epilepticus Jacobwitz M, Mulvihill C, Kaufman MC, Gonzalez AK, Resendiz K, MacDonald JM, Francoeur C, Helbig I, Topjian AA, Abend NS. Neurology . 2022;99(12):e1227-e1238. doi:10.1212/WNL.0000000000200889 Background and Objectives: Few data are available regarding the use of anesthetic infusions for refractory status epilepticus (RSE) in children and neonates, and ketamine use is increasing despite limited data. We aimed to describe the impact of ketamine for RSE in children and neonates. Methods: Retrospective single-center cohort study of consecutive patients admitted to the intensive care units of a quaternary care children’s hospital treated with ketamine infusion for RSE. Results: Sixty-nine patients were treated with a ketamine infusion for RSE. The median age at onset of RSE was 0.7 years (interquartile range 0.15-7.2), and the cohort included 13 (19%) neonates. Three patients (4%) had adverse events requiring intervention during or within 12 hours of ketamine administration, including hypertension in 2 patients and delirium in 1 patient. Ketamine infusion was followed by seizure termination in 32 patients (46%), seizure reduction in 19 patients (28%), and no change in 18 patients (26%). Discussion: Ketamine administration was associated with few adverse events, and seizures often terminated or improved after ketamine administration. Further data are needed comparing first-line and subsequent anesthetic medications for treatment of pediatric and neonatal RSE.

Early timing of anesthesia in status epilepticus is associated with complete recovery: A 7-year retrospective two-center study

OBJECTIVE

This study was undertaken to investigate the efficacy, tolerability, and outcome of different timing of anesthesia in adult patients with status epilepticus (SE).

METHODS

Patients with anesthesia for SE from 2015 to 2021 at two Swiss academic medical centers were categorized as anesthetized as recommended third-line treatment, earlier (as first- or second-line treatment), and delayed (later as third-line treatment). Associations between timing of anesthesia and in-hospital outcomes were estimated by logistic regression.

RESULTS

Of 762 patients, 246 received anesthesia; 21% were anesthetized as recommended, 55% earlier, and 24% delayed. Propofol was preferably used for earlier (86% vs. 55.5% for recommended/delayed anesthesia) and midazolam for later anesthesia (17.2% vs. 15.9% for earlier anesthesia). Earlier anesthesia was statistically significantly associated with fewer infections (17% vs. 32.7%), shorter median SE duration (.5 vs. 1.5 days), and more returns to premorbid neurologic function (52.9% vs. 35.5%). Multivariable analyses revealed decreasing odds for return to premorbid function with every additional nonanesthetic antiseizure medication given prior to anesthesia (odds ratio [OR] = .71, 95% confidence interval [CI] = .53-.94) independent of confounders. Subgroup analyses revealed decreased odds for return to premorbid function with increasing delay of anesthesia independent of the Status Epilepticus Severity Score (STESS; STESS = 1-2: OR = .45, 95% CI = .27-.74; STESS > 2: OR = .53, 95% CI = .34-.85), especially in patients without potentially fatal etiology (OR = .5, 95% CI = .35-.73) and in patients experiencing motor symptoms (OR = .67, 95% CI = .48-.93).

SIGNIFICANCE

In this SE cohort, anesthetics were administered as recommended third-line therapy in only every fifth patient and earlier in every second. Increasing delay of anesthesia was associated with decreased odds for return to premorbid function, especially in patients with motor symptoms and no potentially fatal etiology.

Constant rate infusion of diazepam or propofol for the management of canine cluster seizures or status epilepticus

INTRODUCTION

Cluster seizures (CS) and status epilepticus (SE) in dogs are severe neurological emergencies that require immediate treatment. Practical guidelines call for constant rate infusion (CRI) of benzodiazepines or propofol (PPF) in patients with seizures not responding to first-line treatment, but to date only few studies have investigated the use of CRI in dogs with epilepsy.

STUDY DESIGN

Retrospective clinical study.

METHODS

Dogs that received CRI of diazepam (DZP) or PPF for antiepileptic treatment during hospitalization at the Veterinary Teaching Hospital of the University of Turin for CS or SE between September 2016 and December 2019 were eligible for inclusion. Favorable outcome was defined as cessation of clinically visible seizure activity within few minutes from the initiation of the CRI, no seizure recurrence within 24 h after discontinuation of CRI through to hospital discharge, and clinical recovery. Poor outcome was defined as recurrence of seizure activity despite treatment or death in hospital because of recurrent seizures, catastrophic consequences of prolonged seizures or no return to an acceptable neurological and clinical baseline, despite apparent control of seizure activity. Comparisons between the number of patients with favorable outcome and those with poor outcome in relation to type of CRI, seizure etiology, reason for presentation (CS or SE), sex, previous AED therapy and dose of PPF CRI were carried out.

RESULTS

A total of 37 dogs, with 50 instances of hospitalization and CRI administered for CS or SE were included in the study. CRI of diazepam (DZP) or PPF was administered in 29/50 (58%) and in 21/50 (42%) instances of hospitalization, respectively. Idiopathic epilepsy was diagnosed in 21/37 (57%), (13/21 tier I and 8/21 tier II); structural epilepsy was diagnosed in 6/37 (16%) of which 4/6 confirmed and 2/6 suspected. A metabolic or toxic cause of seizure activity was recorded in 7/37 (19%). A total of 38/50 (76%) hospitalizations were noted for CS and 12/50 (24%) for SE. In 30/50 (60%) instances of hospitalization, the patient responded well to CRI with cessation of seizure activity, no recurrence in the 24 h after discontinuation of CRI through to hospital discharge, whereas a poor outcome was recorded for 20/50 (40%) cases (DZP CRI in 12/50 and PPF CRI in 8/50). Comparison between the number of patients with favorable outcome and those with poor outcome in relation to type of CRI, seizure etiology, reason for presentation (CS or SE), sex and previous AED therapy was carried out but no statistically significant differences were found.

CONCLUSIONS

The present study is the first to document administration of CRI of DZP or PPF in a large sample of dogs with epilepsy. The medications appeared to be tolerated without major side effects and helped control seizure activity in most patients regardless of seizure etiology. Further studies are needed to evaluate the effects of CRI duration on outcome and complications.

Factors associated with mortality in patients with super-refractory status epilepticus

Super-refractory status epilepticus (SRSE) is a critical condition in which seizures persist despite anesthetic use for 24 h or longer. High mortality has been reported in patients with SRSE, but the cause of death remains unclear. We investigated the factors associated with mortality, including clinical characteristics, SE etiologies and severities, treatments, and responses in patients with SRSE in a 13-year tertiary hospital-based retrospective cohort study comparing these parameters between deceased and surviving patients. SRSE accounted for 14.2% of patients with status epilepticus, and 28.6% of SRSE patients died. Deceased patients were mostly young or middle-aged without known systemic diseases or epilepsy. All deceased patients experienced generalized convulsive status epilepticus and failure of anesthetic tapering-off, significantly higher than survivors. An increased number of second-line anesthetics besides midazolam was observed in the deceased (median, 3, interquartile range 2–3) compared to surviving (1, 1–1; p = 0.0006) patients with prolonged use durations (p = 0.047). For mortality, the cut-off number of second-line anesthetics was 1.5 (AUC = 0.906, p = 0.004). Deceased patients had significantly higher renal and cardiac complications and metabolic acidosis than survivors. In SRSE management, multi-anesthetic use should be carefully controlled to avoid systemic complications and mortality.

Management of status epilepticus: a narrative review

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

Brain pathology in focal status epilepticus: evidence from experimental models

Status Epilepticus (SE) is often a neurological emergency characterized by abnormally sustained, longer than habitual seizures. The new ILAE classification reports that SE "…can have long-term consequences including neuronal death, neuronal injury…depending on the type and duration of seizures". While it is accepted that generalized convulsive SE exerts detrimental effects on the brain, it is not clear if other forms of SE, such as focal non-convulsive SE, leads to brain pathology and contributes to long-term deficits in patients. With the available clinical and experimental data, it is hard to discriminate the specific action of the underlying SE etiologies from that exerted by epileptiform activity. This information is highly relevant in the clinic for better treatment stratification, which may include both medical and surgical intervention for seizure control. Here we review experimental studies of focal SE, with an emphasis on focal non-convulsive SE. We present a repertoire of brain pathologies observed in the most commonly used animal models and attempt to establish a link between experimental findings and human condition(s). The extensive literature on focal SE animal models suggest that the current approaches have significant limitations in terms of translatability of the findings to the clinic. We highlight the need for a more stringent description of SE features and brain pathology in experimental studies in animal models, to improve the accuracy in predicting clinical translation.

Safety and Efficacy of Coma Induction Following First-Line Treatment in Status Epilepticus: A 2-Center Study

OBJECTIVE

To explore the safety and efficacy of artificial coma induction to treat status epilepticus (SE) immediately after first-line antiseizure treatment instead of following the recommended approach of first using second-line drugs.

METHODS

Clinical and electrophysiologic data of all adult patients treated for SE from 2017 to 2018 in the Swiss academic medical care centers from Basel and Geneva were retrospectively assessed. Primary outcomes were return to premorbid neurologic function and in-hospital death. Secondary outcomes were the emergence of complications during SE, duration of SE, and intensive care unit (ICU) and hospital stays.

RESULTS

Of 230 patients, 205 received treatment escalation after first-line medication. Of those, 27.3% were directly treated with artificial coma and 72.7% with second-line nonanesthetic antiseizure drugs. Of the latter, 16.6% were subsequently put on artificial coma after failure of second-line treatment. Multivariable analyses revealed increasing odds for coma induction after first-line treatment with younger age, the presence of convulsions, and an increased SE severity as quantified by the Status Epilepticus Severity Score (STESS). While outcomes and complications did not differ compared to patients with treatment escalation according to the guidelines, coma induction after first-line treatment was associated with shorter SE duration and ICU and hospital stays.

CONCLUSIONS

Early induction of artificial coma is performed in more than every fourth patient and especially in younger patients presenting with convulsions and more severe SE. Our data demonstrate that this aggressive treatment escalation was not associated with an increase in complications but with shorter duration of SE and ICU and hospital stays.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that early induction of artificial coma after unsuccessful first-line treatment for SE is associated with shorter duration of SE and ICU and hospital stays compared to the use of a second-line nonanesthetic antiseizure drug instead of or before anesthetics, without an associated increase in complications.

Association Between Treatment Progression, Disease Refractoriness, and Burden of Illness Among Hospitalized Patients With Status Epilepticus

Importance

Status epilepticus (SE) is associated with poor clinical outcomes and high cost. Increased levels of refractory SE require treatment with additional medications and carry increased morbidity and mortality, but the associations between SE refractoriness, clinical outcomes, and cost remain poorly characterized.

Objective

To examine differences in clinical outcomes and costs associated with hospitalization for SE of varying refractoriness.

Design, Setting, and Participants

A cross-sectional study of 43 988 US hospitalizations from January 1, 2016 to December 31, 2018, was conducted, including patients with primary or secondary International Statistical Classification of Diseases, Tenth Revision, diagnosis specifying "with status epilepticus."

Exposure

Patients were categorized by administration of antiseizure drugs given during hospitalization. Low refractoriness denoted treatment with none or 1 intravenous antiseizure drug. Moderate refractoriness denoted treatment with more than 1 intravenous antiseizure drug. High refractoriness denoted treatment with 1 or more intravenous antiseizure drug, more than 1 intravenous anesthetic, and intensive care unit admission.

Main Outcomes and Measures

Outcomes included discharge disposition, hospital length of stay, intensive care unit length of stay, hospital-acquired conditions, and cost (total and per diem).

Results

Among 43 988 hospitalizations for SE, 22 851 patients (51.9%) were male; mean age was 49.9 years (95% CI, 49.7-50.1 years). There were 14 694 admissions (33.4%) for low refractory, 10 140 (23.1%) for moderate refractory, and 19 154 (43.5%) for highly refractory SE. In-hospital mortality was 11.2% overall, with the highest rates among patients with highly (18.9%) compared with moderate (6.3%) and low (4.6%) refractory SE (P < .001 for all comparisons). Median hospital length of stay was 5 days (interquartile range [IQR], 2-10 days) with greater length of stay in highly (8 days; IQR, 4-15 days) compared with moderate (4 days; IQR, 2-8 days) and low (3 days; IQR, 2-5 days) refractory SE (P < .001 for all comparisons). Patients with highly refractory SE also had greater hospital costs, with median costs of $25 105 (mean [SD], $41 858 [$59 063]) in the high, $10 592 (mean [SD], $18 328 [$30 776]) in the moderate, and $6812 (mean [SD], $11 532 [$17 228]) in the low refractory cohorts (P < .001 for all comparisons).

Conclusions and Relevance

Status epilepticus apparently continues to be associated with a large burden on patients and the US health system, with high mortality and costs that increase with disease refractoriness. Interventions that prevent SE from progressing to a more refractory state may have the potential to improve outcomes and lower costs associated with this neurologic condition.

Pharmacotherapy for Nonconvulsive Seizures and Nonconvulsive Status Epilepticus

Most seizures in critically ill patients are nonconvulsive. A significant number of neurological and medical conditions can be complicated by nonconvulsive seizures (NCSs) and nonconvulsive status epilepticus (NCSE), with brain infections, hemorrhages, global hypoxia, sepsis, and recent neurosurgery being the most prominent etiologies. Prolonged NCSs and NCSE can lead to adverse neurological outcomes. Early recognition requires a high degree of suspicion and rapid and appropriate duration of continuous electroencephalogram (cEEG) monitoring. Although high quality research evaluating treatment with antiseizure medications and long-term outcome is still lacking, it is probable that expeditious pharmacological management of NCSs and NCSE may prevent refractoriness and further neurological injury. There is limited evidence on pharmacotherapy for NCSs and NCSE, although a few clinical trials encompassing both convulsive and NCSE have demonstrated similar efficacy of different intravenous (IV) antiseizure medications (ASMs), including levetiracetam, valproate, lacosamide and fosphenytoin. The choice of specific ASMs lies on tolerability and safety since critically ill patients frequently have impaired renal and/or hepatic function as well as hematological/hemodynamic lability. Treatment frequently requires more than one ASM and occasionally escalation to IV anesthetic drugs. When multiple ASMs are required, combining different mechanisms of action should be considered. There are several enteral ASMs that could be used when IV ASM options have been exhausted. Refractory NCSE is not uncommon, and its treatment requires a very judicious selection of ASMs aiming at reducing seizure burden along with management of the underlying condition.

Refractory and Super-refractory Status Epilepticus

Context

Refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE) are neurological emergencies with considerable mortality and morbidity. In this paper, we provide an overview of causes, evaluation, treatment, and consequences of RSE and SRSE, reflecting the lack of high-quality evidence to inform therapeutic approach.

Sources

This is a narrative review based on personal practice and experience. Nevertheless, we searched MEDLINE (using PubMed and OvidSP vendors) and Cochrane central register of controlled trials, using appropriate keywords to incorporate recent evidence.

Results

Refractory status epilepticus is commonly defined as an acute convulsive seizure that fails to respond to two or more anti-seizure medications including at least one nonbenzodiazepine drug. Super-refractory status epilepticus is a status epilepticus that continues for ≥24 hours despite anesthetic treatment, or recurs on an attempted wean of the anesthetic regimen. Both can occur in patients known to have epilepsy or de novo, with increasing recognition of autoimmune and genetic causes. Electroencephalography monitoring is essential to monitor treatment response in refractory/super-refractory status epilepticus, and to diagnose non-convulsive status epilepticus. The mainstay of treatment for these disorders includes anesthetic infusions, primarily midazolam, ketamine, and pentobarbital. Dietary, immunological, and surgical treatments are viable in selected patients. Management is challenging due to multiple acute complications and long-term adverse consequences.

Conclusions

We have provided a synopsis of best practices for diagnosis and management of refractory/superrefractory status epilepticus and highlighted the lack of sufficient high-quality evidence to drive decision making, ending with a brief foray into avenues for future research.

Update on the management of status epilepticus

PURPOSE OF REVIEW

Randomized controlled trials investigating the initial pharmacological treatment of status epilepticus have been recently published. Furthermore, status epilepticus arising in comatose survivors after cardiac arrest has received increasing attention in the last years. This review offers an updated assessment of status epilepticus treatment in these different scenarios.

RECENT FINDINGS

Initial benzodiazepines underdosing is common and correlates with development of status epilepticus refractoriness. The recently published ESETT trial provides high-level evidence regarding the equivalence of fosphenytoin, valproate, and levetiracetam as a second-line option. Myoclonus or epileptiform transients on electroencephalography occur in up to 1/3 of patients surviving a cardiac arrest. Contrary to previous assumptions regarding an almost invariable association with death, at least 1/10 of them may awaken with reasonably good prognosis, if treated. Multimodal prognostication including clinical examination, EEG, somatosensory evoked potentials, biochemical markers, and neuroimaging help identifying patients with a chance to recover consciousness, in whom a trial with antimyoclonic compounds and at times general anesthetics is indicated.

SUMMARY

There is a continuous, albeit relatively slow progress in knowledge regarding different aspect of status epilepticus; recent findings refine some treatment strategies and help improving patients' outcomes. Further high-quality studies are clearly needed to further improve the management of these patients, especially those with severe, refractory status epilepticus forms.

A Theoretical Paradigm for Evaluating Risk-Benefit of Status Epilepticus Treatment

Aggressive treatment of status epilepticus with anesthetic drugs can provide rapid seizure control, but it might lead to serious medical complications and worse outcomes. Using a decision analysis approach, this concise review provides a framework for individualized decision making about aggressive and nonaggressive treatment in status epilepticus. The authors propose and review the most relevant parameters guiding the risk-benefit analysis of treatment aggressiveness in status epilepticus and present real-world-based case examples to illustrate how these tools could be used at the bedside and serve to guide future research in refractory status epilepticus treatment.

Status Epilepticus-Work-Up and Management in Children

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

Acute Provoked Seizures-Work-Up and Management in Adults

Acute provoked seizures, also known as acute symptomatic seizures, occur secondary to a neurological or systemic precipitant, commonly presenting as a first-time seizure. In this article, we will discuss etiology, emergent protocols, medical work-up, initial treatment, and management of these seizures. The definitions, classifications, and management of convulsive status epilepticus and nonconvulsive status epilepticus in an acute setting will also be reviewed.

Epidemiology of status epilepticus in the United States: A systematic review

OBJECTIVES

Convulsive status epilepticus (CSE) is a life-threatening neurologic emergency, which is defined by the International League Against Epilepsy (ILAE) as bilateral tonic-clonic seizure activity lasting longer than 5 min, while absence status epilepticus (SE) and focal SE are specified as exceeding 10 min. Epidemiological evidence on SE is currently lacking, and the incidence is not well-known, especially in light of changes in the ILAE criteria for SE. The objectives of this systematic literature review were to describe the epidemiology of SE in the US population and the associated burden of illness.

METHODS

A systematic review, including literature and pragmatic searches, was conducted. Literature searches were performed using MEDLINE, Embase, BIOSIS, and Web of Science electronic databases from inception to February 2019. Pragmatic searches of the gray literature were carried out using Google, Google Scholar, conference proceedings, and ClinicalTrials.gov to identify additional sources. Only US-based studies or multinational studies reporting US data of interest were included.

RESULTS

In total, 69 sources were identified. The incidence of all SE in patients of all ages in the USA ranged from 18.3 to 41 per 100,000 people per year. Incidence of all-age CSE rose from 3.5 (1979) to 12.5 (2010) per 100,000 people per year. Status epilepticus incidence followed a bimodal (U-shaped) distribution, with the highest estimates in the first years of life (0-4 years) and after 60 years. Mortality associated with SE varied from 21% over 30 days to 31.2% over 10 years. For CSE, two studies reported similar in-hospital mortalities (9.2% and 10.7%). Median healthcare costs related to SE admission were approximately US$14,500 per adult (17-45 years) and US$8000 per child (0-16 years).

CONCLUSIONS

There is a lack of recent data on the epidemiology and healthcare burden associated with SE. Reports of SE incidence in the USA are highly variable and predate the 2015 ILAE definition of SE. However, the available data suggest a high burden of illness.

Treatment of Refractory Convulsive Status Epilepticus: A Comprehensive Review by the American Epilepsy Society Treatments Committee

Purpose:

Established tonic–clonic status epilepticus (SE) does not stop in one-third of patients when treated with an intravenous (IV) benzodiazepine bolus followed by a loading dose of a second antiseizure medication (ASM). These patients have refractory status epilepticus (RSE) and a high risk of morbidity and death. For patients with convulsive refractory status epilepticus (CRSE), we sought to determine the strength of evidence for 8 parenteral ASMs used as third-line treatment in stopping clinical CRSE.

Methods:

A structured literature search (MEDLINE, Embase, CENTRAL, CINAHL) was performed to identify original studies on the treatment of CRSE in children and adults using IV brivaracetam, ketamine, lacosamide, levetiracetam (LEV), midazolam (MDZ), pentobarbital (PTB; and thiopental), propofol (PRO), and valproic acid (VPA). Adrenocorticotropic hormone (ACTH), corticosteroids, intravenous immunoglobulin (IVIg), magnesium sulfate, and pyridoxine were added to determine the effectiveness in treating hard-to-control seizures in special circumstances. Studies were evaluated by predefined criteria and were classified by strength of evidence in stopping clinical CRSE (either as the last ASM added or compared to another ASM) according to the 2017 American Academy of Neurology process.

Results:

No studies exist on the use of ACTH, corticosteroids, or IVIg for the treatment of CRSE. Small series and case reports exist on the use of these agents in the treatment of RSE of suspected immune etiology, severe epileptic encephalopathies, and rare epilepsy syndromes. For adults with CRSE, insufficient evidence exists on the effectiveness of brivaracetam (level U; 4 class IV studies). For children and adults with CRSE, insufficient evidence exists on the effectiveness of ketamine (level U; 25 class IV studies). For children and adults with CRSE, it is possible that lacosamide is effective at stopping RSE (level C; 2 class III, 14 class IV studies). For children with CRSE, insufficient evidence exists that LEV and VPA are equally effective (level U, 1 class III study). For adults with CRSE, insufficient evidence exists to support the effectiveness of LEV (level U; 2 class IV studies). Magnesium sulfate may be effective in the treatment of eclampsia, but there are only case reports of its use for CRSE. For children with CRSE, insufficient evidence exists to support either that MDZ and diazepam infusions are equally effective (level U; 1 class III study) or that MDZ infusion and PTB are equally effective (level U; 1 class III study). For adults with CRSE, insufficient evidence exists to support either that MDZ infusion and PRO are equally effective (level U; 1 class III study) or that low-dose and high-dose MDZ infusions are equally effective (level U; 1 class III study). For children and adults with CRSE, insufficient evidence exists to support that MDZ is effective as the last drug added (level U; 29 class IV studies). For adults with CRSE, insufficient evidence exists to support that PTB and PRO are equally effective (level U; 1 class III study). For adults and children with CRSE, insufficient evidence exists to support that PTB is effective as the last ASM added (level U; 42 class IV studies). For CRSE, insufficient evidence exists to support that PRO is effective as the last ASM used (level U; 26 class IV studies). No pediatric-only studies exist on the use of PRO for CRSE, and many guidelines do not recommend its use in children aged <16 years. Pyridoxine-dependent and pyridoxine-responsive epilepsies should be considered in children presenting between birth and age 3 years with refractory seizures and no imaging lesion or other acquired cause of seizures. For children with CRSE, insufficient evidence exists that VPA and diazepam infusion are equally effective (level U, 1 class III study). No class I to III studies have been reported in adults treated with VPA for CRSE. In comparison, for children and adults with established convulsive SE (ie, not RSE), after an initial benzodiazepine, it is likely that loading doses of LEV 60 mg/kg, VPA 40 mg/kg, and fosphenytoin 20 mg PE/kg are equally effective at stopping SE (level B, 1 class I study).

Conclusions:

Mostly insufficient evidence exists on the efficacy of stopping clinical CRSE using brivaracetam, lacosamide, LEV, valproate, ketamine, MDZ, PTB, and PRO either as the last ASM or compared to others of these drugs. Adrenocorticotropic hormone, IVIg, corticosteroids, magnesium sulfate, and pyridoxine have been used in special situations but have not been studied for CRSE. For the treatment of established convulsive SE (ie, not RSE), LEV, VPA, and fosphenytoin are likely equally effective, but whether this is also true for CRSE is unknown. Triple-masked, randomized controlled trials are needed to compare the effectiveness of parenteral anesthetizing and nonanesthetizing ASMs in the treatment of CRSE.

The first-line management of psychogenic non-epileptic seizures (PNES) in adults in the emergency: a practical approach

Distinguishing non-epileptic events, especially psychogenic non-epileptic seizures (PNES), from epileptic seizures (ES) constitutes a diagnostic challenge. Misdiagnoses are frequent, especially when video-EEG recording, the gold-standard for PNES confirmation, cannot be completed. The issue is further complicated in cases of combined PNES with ES. In emergency units, a misdiagnosis can lead to extreme antiepileptic drug escalade, unnecessary resuscitation measures (intubation, catheterization, etc.), as well as needless biologic and imaging investigations. Outside of the acute window, an incorrect diagnosis can lead to prolonged hospitalization or increase of unhelpful antiepileptic drug therapy. Early recognition is thus desirable to initiate adequate treatment and improve prognosis. Considering experience-based strategies and a thorough review of the literature, we aimed to present the main clinical clues for physicians facing PNES in non-specialized units, before management is transferred to epileptologists and neuropsychiatrists. In such conditions, patient recall or witness-report provide the first orientation for the diagnosis, recognizing that collected information may be inaccurate. Thorough analysis of an event (live or based on home-video) may lead to a clinical diagnosis of PNES with a high confidence level. Indeed, a fluctuating course, crying with gestures of frustration, pelvic thrusting, eye closure during the episode, and the absence of postictal confusion and/or amnesia are highly suggestive of PNES. Moreover, induction and/or inhibition tests of PNES have a good diagnostic value when positive. Prolactinemia may also be a useful biomarker to distinguish PNES from epileptic seizures, especially following bilateral tonic-clonic seizures. Finally, regardless the level of certainty in the diagnosis of the PNES, it is important to subsequently refer the patient for epileptological and neuropsychiatric follow-up.

Causes of Death in Status Epilepticus

OBJECTIVES

To determine the causes of death in patients with status epilepticus. To analyze the relative contributions of seizure etiology, seizure refractoriness, use of mechanical ventilation, anesthetic drugs for seizure control, and medical complications to in-hospital and 90-day mortality, hospital length of stay, and discharge disposition.

DESIGN

Retrospective cohort.

SETTING

Single-center neuroscience ICU.

PARTICIPANTS

Patients with status epilepticus were identified by retrospective search of electronic database from January 1, 2011, to December 31, 2016.

INTERVENTIONS

Review of electronic medical records.

MEASUREMENTS AND MAIN RESULTS

Demographics, clinical characteristics, treatments, and outcomes were collected. Univariable and multivariable logistic regression analysis were used to determine whether the use of anesthetic drugs, mechanical ventilation, Status Epilepticus Severity Score, refractoriness of seizures, etiology of seizures, or medical complications were associated with in-hospital, 90-day mortality or discharge disposition. Among 244 patients with status epilepticus (mean age was 64 yr [interquartile range, 42-76], 55% male, median Status Epilepticus Severity Score 3 [interquartile range, 2-4]), 24 received anesthetic drug infusions for seizure control. In-hospital and 90-day mortality rates were 9.2% and 19.2%, respectively. Death was preceded by withdrawal of life-sustaining treatment in 19 patients (86.3%) and cardiac arrest in three (13.7%). Only Status Epilepticus Severity Score was associated with in-hospital and 90-day mortality, whereas the use of anesthetic drugs for seizure control, mechanical ventilation, medical complications, etiology, and refractoriness of seizures were not. Hospital length of stay was longer in patients with medical complications (p = 0.0091), refractory seizures (p = 0.0077), and in those who required anesthetic drugs for seizure control (p = 0.0035). Patients who had refractory seizures were less likely to be discharged home (odds ratio, 0.295; CI, 0.143-0.608; p = 0.0009).

CONCLUSIONS

In this cohort, death primarily resulted from the underlying neurologic disease and withdrawal of life-sustaining treatment and not from our treatment choices. Use of anesthetic drugs, medical complications, and mechanical ventilation were not associated with in-hospital and 90-day mortality.

Status epilepticus severity score as a predictor for the length of stay at hospital for acute-phase treatment in convulsive status epilepticus

To date, hospital length of stay (LOS) determinants for convulsive status epilepticus's (CSE) acute-phase treatment have not been sufficiently investigated, as opposed to those for status epilepticus's (SE) outcome predictors, such as status epilepticus severity score (STESS). Here, we aimed at assessing the significance of STESS in the LOS in patients with CSE. We retrospectively reviewed consecutive adult patients with CSE who were transported to the emergency department of our urban tertiary care hospital in Tokyo, Japan. The study period was from August 2010 to September 2015. The primary endpoint was the LOS of patients with CSE who were directly discharged after acute-phase treatment, and survival analysis for LOS until discharge was conducted. As a result, among 132 eligible patients with CSE admitted to our hospital, 96 (72.7%) were directly discharged with a median LOS of 10 days (IQR: 4-19 days). CSE patients with severe seizures, represented by higher STESS (≥3), had a significantly longer LOS after adjustments with multiple covariates (p = 0.016, in restricted mean survival time analysis). Additionally, prediction for the binomial longer/shorter LOS achieved better performance when STESS was incorporated into the prediction model. Our findings indicate that STESS can also be used as a rough predictor of longer LOS at index admission of patients with CSE.

Factors affecting mortality of refractory status epilepticus

OBJECTIVE

The aim of this study was to determine the factors affecting the mortality of refractory status epilepticus (RSE) in comparison with non-refractory status epilepticus (non-RSE).

MATERIAL-METHOD

Included in this retrospective study were 109 status epilepticus cases who were hospitalized in the neurological intensive care unit Katip Celebi University. Fifty-two were RSE and 57 were non-RSE. All clinical data were gathered from the hospital archives. Factors which may cause mortality were categorized for statistical analysis.

RESULTS

While elderly age, continuous clinical seizure activity, absence of former seizure, infection, prolonged stay of ICU, anesthesia, and cardiac comorbidity were significantly related to mortality in the RSE subgroup, potentially fatal accompanying diseases were significantly related to mortality in the non-RSE subgroup. No significant relationship was found between mortality and refractoriness. Multivariate analysis revealed that a Glasgow Coma Score (GCS) at presentation of 8 or lower was the independent predictor of mortality both in the general SE population (P = .017) and in the RSE subgroup (P = .007). Intubation (P = .011) and hypotension (P = .011) were the other independent predictors of mortality in the general SE population. No independent predictor of mortality was detected in the non-RSE subgroup.

DISCUSSION/CONCLUSION

Intubation, hypotension, and a low GCS at presentation could be the main factors which could alert clinicians of an increased risk of mortality in SE patients. Although non-RSE and RSE had similar rates of mortality in the ICU, the mortality-related factors of SE vary in the RSE and the non-RSE subgroups.

Predictors of mortality at one year after generalized convulsive status epilepticus

BACKGROUND

Status epilepticus (SE) is a life-threatening neurologic emergency, which requires prompt medical treatment. Little is known of the long-term survival of SE. The aim of this study was to investigate which factors influence 90 days and 1-year mortality after SE.

MATERIALS AND METHODS

This retrospective study includes all consecutive adult (>16 years) patients (N = 70) diagnosed with generalized convulsive SE (GCSE) in Helsinki University Central Hospital (HUCH) emergency department (ED) over 2 years. We defined specific factors including patient demographics, GCSE characteristics, treatment, complications, delays in treatment, and outcome at hospital discharge and determined their relation to 90 days and 1-year mortality after GCSE by using logistic regression models. Survival analyses at 1 year after GCSE were performed with Cox proportional hazards regression analysis.

RESULTS

In-hospital mortality was 7.1%. Mortality rate was 14.3% at 90 days and 24.3% at 1 year after GCSE. In the univariate logistic regression analysis, Status Epilepticus Severity Score > 4 (STESS) (ODDS = 7.30, p = 0.012), worse-than-baseline condition at hospital discharge (ODDS = 3.5, p = 0.006), long delays in attaining seizure freedom (ODDS = 2.2, p = 0.041), and consciousness (ODDS = 3.4, p = 0.014) were risk factors for mortality at 90 days whereas epilepsy (ODDS = 0.2, p = 0.014) and Glasgow Outcome Scale (GOS) >3 at hospital discharge (ODDS = 0.05, p = 0.006) were protective factors. Risk factors for mortality at 1 year were STESS >4 (ODDS = 5.1, p = 0.028), use of vasopressors (ODDS = 8.2, p = 0.049), and worse-than-baseline condition at discharge (ODDS = 7.8, p = 0.010) while GOS >3 (ODDS = 0.2, p = 0.005) was protective. The univariate survival analysis at 1 year confirmed the significant findings regarding parameters STESS >4 (Hazard ratio (HR) = 4.1, p = 0.009), worse-than-baseline condition (HR = 6.2, p = 0.015), GOS >3 (HR = 0.2, p = 0.004) at hospital discharge and epilepsy (HR = 0.4, p = 0.044). Additionally, diagnostic delay over 6 h (HR = 3.8, p = 0.022) and Complication Burden Index (CBI) as an ordinal variable (0-2, 3-6, >6) (HR = 2.7, p = 0.027) were predictive for mortality. In the multivariate survival analysis, STESS > 4 (HR = 5.1, p = 0.007), CBI (HR = 3.2, p = 0.025, ordinal variable), diagnostic delay over 6 h (HR = 7.2, p = 0.003), and worse-than-baseline condition at hospital discharge (HR = 5.8, p = 0.027) were all independent risk factors for mortality at 1 year.

CONCLUSIONS

Severe form of SE, delayed recognition of GCSE, high number of complications during treatment period, and poor condition at hospital discharge are all independent predictors of long-term mortality. Most of these factors are also associated with mortality at 90 days, though at that point, delays in treatment seem to have a greater impact on prognosis than at 1 year. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Why do patients die after status epilepticus?

The epidemiology of status epilepticus (SE) and predictors of outcome in particular have been well described with consistent findings around the world. Understanding of the actual causes of death in patients hospitalized with SE is limited. The following is a summary of published information about causes of death in patients hospitalized with SE and a reconciling of conflicting studies examining the influence of continuous intravenous anesthetic drugs on the mortality of SE. A recently published paper was presented at the Colloquium and is summarized here, along with new data addressing an audience question about withdrawal of care in SE. In the spirit of the conference, we end with a call to arms and invitation for collaborators. Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Nonconvulsive seizures and nonconvulsive status epilepticus in the neuro ICU should or should not be treated aggressively: A debate

This article presents a "debate" about the appropriate level of aggressiveness of treatment for nonconvulsive status epilepticus (NCSE), held at the International Congress of Clinical Neurophysiology in Washington D.C. on 4 May 2018. The proposition for discussion was "Nonconvulsive seizures and status epilepticus in the intensive care unit should be treated aggressively." Dr. Andrea O. Rossetti from Lausanne, Switzerland, spoke in support of the proposition and Dr. Lawrence J. Hirsch from New Haven, Connecticut, discussed reasons for rejecting the proposal. Dr. Frank W. Drislane from Boston, Massachusetts, was asked by the conference organizers to add comments and perspective.

Duration of therapeutic coma and outcome of refractory status epilepticus

OBJECTIVE

Examine the association of duration of therapeutic coma (TC) with seizure recurrence, morbidity, and mortality in refractory status epilepticus (RSE). Define an optimal window for TC that provides sustained seizure control and minimizes complications.

METHODS

Retrospective, observational cohort study involving patients who presented with RSE to the University of Alabama at Birmingham or the University of California at San Francisco from 2010 to 2016. Relationship of duration of TC with primary and secondary outcomes was evaluated using two-sample t tests, simple linear regression, and chi-square tests. Multivariable linear and logistic regression models were used to identify independent predictors. Predictive ability of TC for seizure recurrence was quantified using a receiver-operating characteristic curve. Youden index was used to determine an optimal cutoff value.

RESULTS

Multivariable analysis of clinical and treatment characteristics of 182 patients who were treated predominantly with propofol as anesthetic agent showed that longer duration of the first trial of TC (27.2 vs 15.6 hours) was independently associated with a higher chance of seizure recurrence following the first weaning attempt (P = 0.038) but not with poor functional neurologic outcome upon discharge, in-hospital complications, or mortality. Furthermore, higher doses of anesthetic utilized during the first trial of TC were independently associated with fewer in-hospital complications (P = 0.003) and associated with a shorter duration of mechanical ventilation and total length of stay. Duration of TC was identified as an independent predictor of seizure recurrence with an optimal cutoff point at 35 hours.

SIGNIFICANCE

This study suggests that a shorter duration yet deeper TC as treatment for RSE may be more effective and safer than the currently recommended TC duration of 24-48 hours. Prospective and randomized trials should be conducted to validate these assertions.

Systematic review and meta-analysis of propofol versus barbiturates for controlling refractory status epilepticus

Background

Several studies have compared the efficacy and safety of propofol and barbiturates in the treatment of refractory status epilepticus (RSE). This study aims to quantitatively assess the advantages and disadvantages of propofol and barbiturates in controlling RSE.

Methods

We searched for studies with relevant data from the PubMed, Embase, Ovid, Cochrane Library, Springer Link, Web of Science, and China National Knowledge Infrastructure databases. By calculating odds ratios and standardized mean differences with 95% confidence intervals, we assessed the disease control rate (DCR), case fatality rate (CFR), average control time (ACT), average tracheal intubation placement time (ATIPT), and incidence of hypotension between propofol and barbiturates in treating RSE.

Results

Seven studies with 261 patients were included in this analysis. Meta-analysis revealed that the DCR of propofol was higher than that of barbiturates (p < 0.001) and that the CFR (p = 0.382) between the two treatment did not significantly differ in controlling RSE. Propofol shortened the ACT (p < 0.001) of RSE and reduced the ATIPT (p < 0.001) of patients with RSE more extensively than did barbiturates and did not increase the incidence of hypotension (p = 0.737).

Conclusions

In comparison with barbiturates, propofol can control RSE and shorten ATIPT in a more efficient and timely manner. Moreover, the drug does not increase the incidence of hypotension and CFR.

Developing a personalized closed-loop controller of medically-induced coma in a rodent model

OBJECTIVE

Personalized automatic control of medically-induced coma, a critical multi-day therapy in the intensive care unit, could greatly benefit clinical care and further provide a novel scientific tool for investigating how the brain response to anesthetic infusion rate changes during therapy. Personalized control would require real-time tracking of inter- and intra-subject variabilities in the brain response to anesthetic infusion rate while simultaneously delivering the therapy, which has not been achieved. Current control systems for medically-induced coma require a separate offline model fitting experiment to deal with inter-subject variabilities, which would lead to therapy interruption. Removing the need for these offline interruptions could help facilitate clinical feasbility. In addition, current systems do not track intra-subject variabilities. Tracking intra-subject variabilities is essential for studying whether or how the brain response to anesthetic infusion rate changes during therapy. Further, such tracking could enhance control precison and thus help facilitate clinical feasibility.

APPROACH

Here we develop a personalized closed-loop anesthetic delivery (CLAD) system in a rodent model that tracks both inter- and intra-subject variabilities in real time while simultaneously controlling the anesthetic in closed loop. We tested the CLAD in rats by administrating propofol to control the electroencephalogram (EEG) burst suppression. We first examined whether the CLAD can remove the need for offline model fitting interruption. We then used the CLAD as a tool to study whether and how the brain response to anesthetic infusion rate changes as a function of changes in the depth of medically-induced coma. Finally, we studied whether the CLAD can enhance control compared with prior systems by tracking intra-subject variabilities.

MAIN RESULTS

The CLAD precisely controlled the EEG burst suppression in each rat without performing offline model fitting experiments. Further, using the CLAD, we discovered that the brain response to anesthetic infusion rate varied during control, and that these variations correlated with the depth of medically-induced coma in a consistent manner across individual rats. Finally, tracking these variations reduced control bias and error by more than 70% compared with prior systems.

SIGNIFICANCE

This personalized CLAD provides a new tool to study the dynamics of brain response to anesthetic infusion rate and has significant implications for enabling clinically-feasible automatic control of medically-induced coma.

Factors predicting cessation of status epilepticus in clinical practice: Data from a prospective observational registry (SENSE)

OBJECTIVE

To investigate the initial termination rate of status epilepticus (SE) in a large observational study and explore associated variables.

METHODS

Data of adults treated for SE were collected prospectively in centers in Germany, Austria, and Switzerland, during 4.5 years. Incident episodes of 1,049 patients were analyzed using uni- and multivariate statistics to determine factors predicting cessation of SE within 1 hour (for generalized convulsive SE [GCSE]) and 12 hours (for non-GCSE) of initiating treatment.

RESULTS

Median age at SE onset was 70 years; most frequent etiologies were remote (32%) and acute (31%). GCSE was documented in 43%. Median latency between SE onset and first treatment was 30 minutes in GCSE and 150 minutes in non-GCSE. The first intravenous compound was a benzodiazepine in 86% in GCSE and 73% in non-GCSE. Bolus doses of the first treatment step were lower than recommended by current guidelines in 76% of GCSE patients and 78% of non-GCSE patients. In 319 GCSE patients (70%), SE was ongoing 1 hour after initiating treatment and in 342 non-GCSE patients (58%) 12 hours after initiating treatment. Multivariate Cox regression demonstrated that use of benzodiazepines as first treatment step and a higher cumulative dose of anticonvulsants within the first period of treatment were associated with shorter time to cessation of SE for both groups.

INTERPRETATION

In clinical practice, treatment guidelines were not followed in a substantial proportion of patients. This underdosing correlated with lack of cessation of SE. Our data suggest that sufficiently dosed benzodiazepines should be used as a first treatment step. ANN NEUROL 2019;85:421-432.

Approach to Managing Periodic Discharges

Use of continuous EEG monitoring in the intensive care unit setting has increased detection of not only subclinical seizures, but also patterns of discharges that have epileptiform features and periodicity yet do not meet the criteria for seizures. These periodic discharges present a clinical challenge: some patterns may reflect brain injury that has already occurred, although there is evidence that some periodic discharges represent an ongoing process causing additional brain injury and necessitate treatment. Herein, we review the available data regarding the clinical significance of different categories of periodic discharges, specifically those that have features physiologically similar to seizures. We propose a stepwise approach to assessment and management of periodic discharges and lay out the general paradigm of (1) clinical assessment including benzodiazepine trial, (2) EEG assessment, with a focus on discharge frequency, and (3) integration of adjunctive data such as neuroimaging and metabolic data when available. A flowchart is provided to simplify and summarize this approach. The goal of this approach is to treat patterns associated with increased risk of seizures and/or additional brain injury, while avoiding unnecessary interventions.

Anesthetic drugs for the treatment of status epilepticus

Worsening pharmacoresistance to antiseizure drugs is common with ongoing excitotoxic neuronal and systemic injury. Early initiation of anesthetic drugs in refractory status epilepticus (RSE) may halt these processes while allowing time for treatment targeting the cause of the seizures. Current guidelines support the use of anesthetic drugs as the third line pharmacologic therapy in generalized convulsive status epilepticus but do not clearly define the indications for these drugs in other types of status epilepticus. There is wide practice variation in choice of third line therapy for RSE, but there is overall consensus that anesthetics should be initiated earlier in generalized convulsive status epilepticus than in nonconvulsive forms. More recently, doubt has been cast on the appropriateness of anesthetic treatment of RSE following a series of studies associating their use with higher mortality and morbidity. This suggests that efforts should focus on determination of who benefits most, optimal use, and prevention of refractoriness. The risk-benefit ratio of anesthetic use is discussed, with specific indications proposed. In addition, anesthetic dosing, supportive neurocritical care, electroencephalogram suppression target, and weaning of anesthesia are reviewed.

New Developments in Refractory Status Epilepticus

Status epilepticus (SE) is a medical emergency and presents with either a continuous prolonged seizure or multiple seizures without full recovery of consciousness in between them. The goals of treatment are prompt recognition, early seizure termination, and simultaneous evaluation for any potentially treatable cause. Improved understanding of the pathophysiology has led to a more practical definition. New data have emerged regarding the safety and efficacy of alternative agents, which are increasingly used in the management of these patients. Continuous electroencephalogram monitoring is more widely used and has revealed a higher incidence of subclinical seizures than was previously thought.

Treatment of Refractory and Super-refractory Status Epilepticus

Refractory and super-refractory status epilepticus (SE) are serious illnesses with a high risk of morbidity and even fatality. In the setting of refractory generalized convulsive SE (GCSE), there is ample justification to use continuous infusions of highly sedating medications-usually midazolam, pentobarbital, or propofol. Each of these medications has advantages and disadvantages, and the particulars of their use remain controversial. Continuous EEG monitoring is crucial in guiding the management of these critically ill patients: in diagnosis, in detecting relapse, and in adjusting medications. Forms of SE other than GCSE (and its continuation in a "subtle" or nonconvulsive form) should usually be treated far less aggressively, often with nonsedating anti-seizure drugs (ASDs). Management of "non-classic" NCSE in ICUs is very complicated and controversial, and some cases may require aggressive treatment. One of the largest problems in refractory SE (RSE) treatment is withdrawing coma-inducing drugs, as the prolonged ICU courses they prompt often lead to additional complications. In drug withdrawal after control of convulsive SE, nonsedating ASDs can assist; medical management is crucial; and some brief seizures may have to be tolerated. For the most refractory of cases, immunotherapy, ketamine, ketogenic diet, and focal surgery are among several newer or less standard treatments that can be considered. The morbidity and mortality of RSE is substantial, but many patients survive and even return to normal function, so RSE should be treated promptly and as aggressively as the individual patient and type of SE indicate.

Advancements in the critical care management of status epilepticus

PURPOSE OF REVIEW

Status epilepticus has a high morbidity and mortality. There are little definitive data to guide management; however, new recent data continue to improve understanding of management options of status epilepticus. This review examines recent advancements regarding the critical care management of status epilepticus.

RECENT FINDINGS

Recent studies support the initial treatment of status epilepticus with early and aggressive benzodiazepine dosing. There remains a lack of prospective randomized controlled trials comparing different treatment regimens. Recent data support further study of intravenous lacosamide as an urgent-control therapy, and ketamine and clobazam for refractory status epilepticus. Recent data support the use of continuous EEG to help guide treatment for all patients with refractory status epilepticus and to better understand epileptic activity that falls on the ictal-interictal continuum. Recent data also improve our understanding of the relationship between periodic epileptic activity and brain injury.

SUMMARY

Many treatments are available for status epilepticus and there are much new data guiding the use of specific agents. However, there continues to be a lack of prospective data supporting specific regimens, particularly in cases of refractory status epilepticus.

Nonconvulsive status epilepticus after convulsive status epilepticus: Clinical features, outcomes, and prognostic factors

OBJECTIVES

To investigate clinical characteristics and outcomes of nonconvulsive status epilepticus (NCSE) after convulsive status epilepticus (CSE) and determine risk factors for unfavorable outcomes.

METHODS

We reviewed consecutive patients with NCSE after CSE over eight years in the neurological intensive care unit. Clinical presentations and the Salzburg EEG criteria for NCSE were used to identify patients with NCSE after CSE. Demographics, clinical features, and anti-epileptic treatment responses were collected and analyzed. Modified Rankin Scale (mRS) was used to evaluate three-month outcomes. A multivariate logistic regression model was used to determine independent prognostic factors.

RESULTS

Among 145 consecutive patients with convulsive SE, 48 (33.1%) patents eventually evolved into NCSE. Two patients with cerebral anoxia were exclude. At three-month follow-up, 23 patients (50.0%) had mRS ≥ 3, and 16 (34.8%) died. Thirty-two patients (69.6%) were given continuous intravenous anesthetic drugs (CIVADs). Fourteen patients (30.4%) had CIVAD at the rate >50% proposed maximal dose (PMD). There was a single predictor factor found significant after multivariate logistic regression analysis: the recurrence of EEG seizures within two hours of initiation of CIVAD at a dose of greater than half the proposed maximal dose (OR, 9.63; 95%CI, 1.08-86.18; p = 0.043). The use of CIVAD, even with a high dose (>50% PMD), was not independently associated with unfavorable outcomes.

CONCLUSIONS

The recurrence of EEG seizures within two hours of initiation of CIVAD at a dose of greater than half the proposed maximal dose predicts unfavorable outcomes in NCSE after CSE. The refractoriness of the seizures might be a significantly greater risk for poor outcome in NCSE after CSE than treatment with CIVADs.

Systemic Complications Following Status Epilepticus

PURPOSE OF REVIEW

Status epilepticus (SE) is a multisystem disorder. Initially, complications of a massive catecholamine release followed by the side effects of medical therapies, impact patients' outcomes. The aim of this article is to provide an updated summary of the systemic complications following SE.

RECENT FINDINGS

In recent years, the importance of the multifaceted nature of SE and its relationship with clinical outcomes has been increasingly recognized. The cumulative systemic effects of prolonged seizures and their treatment contribute to morbidity and mortality in this condition. Most systemic complications after SE are predictable. Anticipating their occurrence and respecting a number of simple guidelines may improve the prognosis of these patients.

New Developments in Refractory Status Epilepticus

Status epilepticus (SE) is a medical emergency and presents with either a continuous prolonged seizure or multiple seizures without full recovery of consciousness in between them. The goals of treatment are prompt recognition, early seizure termination, and simultaneous evaluation for any potentially treatable cause. Improved understanding of the pathophysiology has led to a more practical definition. New data have emerged regarding the safety and efficacy of alternative agents, which are increasingly used in the management of these patients. Continuous electroencephalogram monitoring is more widely used and has revealed a higher incidence of subclinical seizures than was previously thought.

An update on the recognition and treatment of non-convulsive status epilepticus in the intensive care unit

INTRODUCTION

Non-convulsive status epilepticus (NCSE) is a complex and diverse condition which is often an under-recognised entity in the intensive care unit. When NCSE is identified the optimal treatment strategy is not always clear. Areas covered: This review is based on a literature review of the key literature in the field over the last 5-10 years. The articles were selected based on their importance to the field by the authors. Expert commentary: This review discusses the complex situations when a neurological consultation may occur in a critical care setting and provides an update on the latest evidence regarding the recognition of NCSE and the decision making around determining the aggressiveness of treatment. It also considers the ictal-interictal continuum of conditions which may be met with, particularly in the era of continuous EEG, and provides an approach for dealing with these. Suggestions for how the field will develop are discussed.

Transition from intravenous to enteral ketamine for treatment of nonconvulsive status epilepticus

Background

Nonconvulsive status epilepticus (NCSE) is a diagnosis that is often challenging and one that may progress to refractory NCSE. Ketamine is a noncompetitive N-methyl-d-aspartate antagonist that increasingly has been used to treat refractory status epilepticus. Current Neurocritical Care Society guidelines recommend intravenous (IV) ketamine infusion as an alternative treatment for refractory status epilepticus in adults. On the other hand, enteral ketamine use in NCSE has been reported in only 6 cases (1 adult and 5 pediatric) in the literature to date.

Case presentation

A 33-year-old woman with a history of poorly controlled epilepsy presented with generalized tonic-clonic seizures, followed by recurrent focal seizures that evolved into NCSE. This immediately recurred within 24 h of a prior episode of NCSE that was treated with IV ketamine. Considering her previous response, she was started again on an IV ketamine infusion, which successfully terminated NCSE. This time, enteral ketamine was gradually introduced while weaning off the IV formulation. Treatment with enteral ketamine was continued for 6 months and then tapered off. There was no recurrence of NCSE or seizures and no adverse events noted during the course of treatment.

Conclusion

This case supports the use of enteral ketamine as a potential adjunct to IV ketamine in the treatment of NCSE, especially in cases without coma. Introduction of enteral ketamine may reduce seizure recurrence, duration of stay in ICU, and morbidity associated with intubation.

First-in-man allopregnanolone use in super-refractory status epilepticus

Super‐refractory status epilepticus (SRSE) is associated with high morbidity and mortality. Treatment of SRSE is complicated by progressive cortical hyperexcitability believed to result in part from synaptic GABA receptor internalization and desensitization. Allopregnanolone, a neurosteroid that positively modulates synaptic and extrasynaptic GABA_A receptors, has been proposed as a novel treatment. We describe the first two patients with SRSE who were each successfully treated with a 120‐h continuous infusion of allopregnanolone. Both patients recovered from prolonged SRSE with good cognitive outcomes.