The management of refractory generalised convulsive and complex partial status epilepticus in three European countries: a survey among epileptologists and critical care neurologists

The Origin of the Burst-Suppression Paradigm in Treatment of Status Epilepticus

After electroencephalography (EEG) was introduced in hospitals, early literature recognized burst-suppression pattern (BSP) as a distinctive EEG pattern characterized by intermittent high-power oscillations alternating with isoelectric periods in coma and epileptic encephalopathies of childhood or the pattern could be induced by general anesthesia and hypothermia. The term was introduced by Swank and Watson in 1949 but was initially described by Derbyshire et al. in 1936 in their study about the anesthetic effects of tribromoethanol. Once the EEG/BSP pattern emerged in the literature as therapeutic goal in refractory status epilepticus, researchers began exploring whether the depth of EEG suppression correlated with improved seizure control and clinical outcomes. We can conclude that, from a historical perspective, the evidence to suppress the brain to a BSP when treating status epilepticus is inconclusive.

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.

Association Between Induced Burst Suppression and Clinical Outcomes in Patients With Refractory Status Epilepticus: A 9-Year Cohort Study

BACKGROUND AND OBJECTIVES

To investigate the frequency of induced EEG burst suppression pattern during continuous IV anesthesia (IVAD) and associated outcomes in adult patients treated for refractory status epilepticus (RSE).

METHODS

Patients with RSE treated with anesthetics at a Swiss academic care center from 2011 to 2019 were included. Clinical data and semiquantitative EEG analyses were assessed. Burst suppression was categorized as incomplete burst suppression (with ≥20% and <50% suppression proportion) or complete burst suppression (with ≥50% suppression proportion). The frequency of induced burst suppression and association of burst suppression with outcomes (persistent seizure termination, in-hospital survival, and return to premorbid neurologic function) were the endpoints.

RESULTS

We identified 147 patients with RSE treated with IVAD. Among 102 patients without cerebral anoxia, incomplete burst suppression was achieved in 14 (14%) with a median of 23 hours (interquartile range [IQR] 1-29) and complete burst suppression was achieved in 21 (21%) with a median of 51 hours (IQR 16-104). Age, Charlson comorbidity index, RSE with motor symptoms, the Status Epilepticus Severity Score and arterial hypotension requiring vasopressors were identified as potential confounders in univariable comparisons between patients with and without any burst suppression. Multivariable analyses revealed no associations between any burst suppression and the predefined endpoints. However, among 45 patients with cerebral anoxia, induced burst suppression was associated with persistent seizure termination (72% without vs 29% with burst suppression, p = 0.004) and survival (50% vs 14% p = 0.005).

DISCUSSION

In adult patients with RSE treated with IVAD, burst suppression with ≥50% suppression proportion was achieved in every fifth patient and not associated with persistent seizure termination, in-hospital survival, or return to premorbid neurologic function.

Balancing the risks and benefits of anesthetics in status epilepticus

PURPOSE

According to international guidelines, status epilepticus refractory to first- and second-line antiseizure medication should be treated with anesthetics. Therefore, continuously delivered intravenous midazolam, propofol, or barbiturates are recommended as third-line therapy. While electroencephalographically (EEG)-controlled titration of anesthetics to seizure termination or to the emergence of an EEG burst-suppression pattern makes sense, evidence of the efficacy and tolerability of such third-line treatment is limited and concerns regarding the risks of anesthesia remain. The lack of treatment alternatives and persistent international discord reflecting contradictory results from some studies leave clinicians on their own when deciding to escalate treatment. In this conference-accompanying narrative review, we highlight the challenges of EEG-monitored third-line treatment and discuss recent studies that examined earlier administration of anesthetics.

RESULTS

Based on the literature, maintaining continuous burst suppression is difficult despite the constant administration of anesthetics, and the evidence for burst suppression as an adequate surrogate target is limited by methodological shortcomings as acknowledged by international guidelines. In our Swiss cohort including 102 patients with refractory status epilepticus, burst suppression as defined by the American Clinical Neurophysiology Society's Critical Care EEG Terminology 2021 was established in only 21%. Besides case reports suggesting that rapid but short-termed anesthesia can be sufficient to permanently stop seizures, a study including 205 patients revealed that anesthesia as second-line treatment was associated with a shorter median duration of status epilepticus (0.5 versus 12.5 days, p < 0.001), median ICU (2 versus 5.5 days, p < 0.001) and hospital stay (8 versus 17 days, p < 0.001) with equal rates of complications when compared to anesthesia as third-line treatment.

CONCLUSIONS

Recent investigations have led to important findings and new insights regarding the use of anesthetics in refractory status epilepticus. However, numerous methodological limitations and remaining questions need to be considered when it comes to the translation into clinical practice, and, in consequence, call for prospective randomized studies. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Therapeutically induced EEG burst-suppression pattern to treat refractory status epilepticus—what is the evidence?

Current guidelines advocate to treat refractory status epilepticus (RSE) with continuously administered anesthetics to induce an artificial coma if first- and second-line antiseizure drugs have failed to stop seizure activity. A common surrogate for monitoring the depth of the artificial coma is the appearance of a burst-suppression pattern (BS) in the EEG. This review summarizes the current knowledge on the origin and neurophysiology of the BS phenomenon as well as the evidence from the literature for the presumed benefit of BS as therapy in adult patients with RSE.

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.

Electrographic predictors of successful weaning from anaesthetics in refractory status epilepticus

Intravenous third-line anaesthetic agents are typically titrated in refractory status epilepticus to achieve either seizure suppression or burst suppression on continuous EEG. However, the optimum treatment paradigm is unknown and little data exist to guide the withdrawal of anaesthetics in refractory status epilepticus. Premature withdrawal of anaesthetics risks the recurrence of seizures, whereas the prolonged use of anaesthetics increases the risk of treatment-associated adverse effects. This study sought to measure the accuracy of features of EEG activity during anaesthetic weaning in refractory status epilepticus as predictors of successful weaning from intravenous anaesthetics. We prespecified a successful anaesthetic wean as the discontinuation of intravenous anaesthesia without developing recurrent status epilepticus, and a wean failure as either recurrent status epilepticus or the resumption of anaesthesia for the purpose of treating an EEG pattern concerning for incipient status epilepticus. We evaluated two types of features as predictors of successful weaning: spectral components of the EEG signal, and spatial-correlation-based measures of functional connectivity. The results of these analyses were used to train a classifier to predict wean outcome. Forty-seven consecutive anaesthetic weans (23 successes, 24 failures) were identified from a single-centre cohort of patients admitted with refractory status epilepticus from 2016 to 2019. Spectral components of the EEG revealed no significant differences between successful and unsuccessful weans. Analysis of functional connectivity measures revealed that successful anaesthetic weans were characterized by the emergence of larger, more densely connected, and more highly clustered spatial functional networks, yielding 75.5% (95% confidence interval: 73.1-77.8%) testing accuracy in a bootstrap analysis using a hold-out sample of 20% of data for testing and 74.6% (95% confidence interval 73.2-75.9%) testing accuracy in a secondary external validation cohort, with an area under the curve of 83.3%. Distinct signatures in the spatial networks of functional connectivity emerge during successful anaesthetic liberation in status epilepticus; these findings are absent in patients with anaesthetic wean failure. Identifying features that emerge during successful anaesthetic weaning may allow faster and more successful anaesthetic liberation after refractory status epilepticus.

A pragmatic approach to intravenous anaesthetics and electroencephalographic endpoints for the treatment of refractory and super-refractory status epilepticus in critical care

Status epilepticus is a common neurological emergency, with overall mortality around 20%. Over half of cases are first time presentations of seizures. The pathological process by which spontaneous seizures are generated arises from an imbalance in excitatory and inhibitory neuronal networks, which if unchecked, can result in alterations in intracellular signalling pathways and electrolyte shifts, which bring about changes in the blood brain barrier, neuronal cell death and eventually cerebral atrophy. This narrative review focusses on the treatment of status epilepticus in adults. Anaesthetic agents interrupt neuronal activity by enhancing inhibitory or decreasing excitatory transmission, primarily via GABA and NMDA receptors. Intravenous anaesthetic agents are commonly used as second or third line drugs in the treatment of refractory status epilepticus, but the optimal timing and choice of anaesthetic drug has not yet been established by high quality evidence. Titration of antiepileptic and anaesthetic drugs in critically ill patients presents a particular challenge, due to alterations in drug absorbtion and metabolism as well as changes in drug distrubution, which arise from fluid shifts and altered protein binding. Furthermore, side effects associated with prolonged infusions of anaesthetic drugs can lead to multi-organ dysfunction and a need for critical care support. Electroencelography can identify patterns of burst suppression, which may be a target to guide weaning of intravenous therapy. Continuous elctroencephalography has the potential to directly impact clinical care, but despite its utility, major barriers exist which have limited its widespread use in clinical practice. A flow chart outlining the timing and dosage of anaesthetic agents used at our institution is provided.

Weaning from antiseizure drugs after new onset status epilepticus

OBJECTIVE

In patients with status epilepticus (SE) without prior epilepsy, there are limited data on the safety of discontinuing antiseizure drugs (ASDs) after seizure control. We aimed to describe seizure recurrence when weaning from ASDs following new onset SE (NOSE).

METHODS

Retrospective review of adult patients with NOSE admitted to Mayo Clinic, Rochester, Minnesota between January 1, 1990 and December 31, 2015 was performed. Weaning was defined as a discontinuation of ASDs following discharge. Patient demographics, SE characteristics, timing of ASD withdrawal, and seizure recurrence were collected.

RESULTS

One hundred seventy-seven patients with mean age 63 ± 18 years were identified; 96 (54.2%) patients had refractory SE (RSE), and 81 (45.8%) had nonrefractory SE. Mean follow-up was 3.8 ± 3.2 years for those successfully weaned off ASDs. One hundred thirty (73.4%) with outpatient follow-up were included in the analysis; 128 (98.5%) patients were discharged on an ASD; 44 of 128 (34.4%) patients underwent weaning from at least 1 ASD following discharge, including 27 of 128 (21.1%) who were completely weaned off of all ASDs. Younger patients (P = 0.009) and those with RSE (P = 0.048, odds ratio = 2.12, 95% confidence interval = 1.00-4.48) tended to undergo weaning. Six of 44 (13.6%) patients had seizure recurrence when weaned off of any ASD, and two of 27 (7.4%) patients completely weaned off all ASDs had seizure recurrence. Two of seven (28.6%) patients who underwent attempted barbiturate weaning experienced seizure recurrence.

SIGNIFICANCE

We found a rate of 13.6% for late seizure recurrence after weaning from at least one ASD in patients with NOSE; seizure recurrence was more likely in patients with RSE treated with barbiturates. Systematic collection of longitudinal data in patients requiring multiple ASDs for NOSE control will provide more conclusive guidance on weaning from ASDs.

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.

Anesthetics and Outcome in Status Epilepticus: A Matched Two-Center Cohort Study

BACKGROUND

The use of anesthetics has been linked to poor outcome in patients with status epilepticus (SE). This association, however, may be confounded, as anesthetics are mostly administered in patients with more severe SE and critical illnesses.

OBJECTIVE

To minimize treatment-selection bias, we assessed the association between continuously administered intravenous anesthetic drugs (IVADs) and outcome in SE patients by a matched two-center study design.

METHODS

This cohort study was performed at the Johns Hopkins Bayview Medical Center, Baltimore, MD, USA and the University Hospital Basel, Basel, Switzerland. All consecutive adult SE patients from 2005 to 2013 were included. Odds ratios (ORs) for death and unfavorable outcome (Glasgow Outcome Score [GOS] 1-3) associated with administration of IVADs were calculated. To account for confounding by known outcome determinants (age, level of consciousness, worst seizure type, acute/fatal etiology, mechanical ventilation, and SE duration), propensity score matching and coarsened exact matching were performed in addition to multivariable regression models.

RESULTS

Among 406 consecutive patients, 139 (34.2%) were treated with IVADs. Logistic regression analyses of the unmatched and matched cohorts revealed increased odds for death and unfavorable outcome in survivors who had received IVADs (unmatched: OR_death = 3.13, 95% confidence interval [CI] 1.47-6.60 and OR_GOS1-3 = 2.51, 95% CI 1.37-4.60; propensity score matched: OR_death = 3.29, 95% CI 1.35-8.05 and OR_GOS1-3 = 2.27, 95% CI 1.02-5.06; coarsened exact matched: OR_death = 2.19, 95% CI 1.27-3.78 and OR_GOS1-3 = 3.94, 95% CI 2.12-7.32).

CONCLUSION

The use of IVADs in SE is associated with death and unfavorable outcome in survivors independent of known confounders and using different statistical approaches. Randomized trials are needed to determine if these associations are biased by outcome predictors not yet identified and hence not accounted for in this study.

Continuous Infusion Antiepileptic Medications for Refractory Status Epilepticus: A Review for Nurses

Status epilepticus requires treatment with emergent initial therapy with a benzodiazepine and urgent control therapy with an additional antiepileptic drug (AED) to terminate clinical and/or electrographic seizure activity. However, nearly one-third of patients will prove refractory to the aforementioned therapies and are prone to a higher degree of neuronal injury, resistance to pharmacotherapy, and death. Current guidelines for refractory status epilepticus (RSE) recommend initiating a continuous intravenous (CIV) anesthetic over bolus dosing with a different AED. Continuous intravenous agents most commonly used for this indication include midazolam, propofol, and pentobarbital, but ketamine is an alternative option. Comparative studies illustrating the optimal agent are lacking, and selection is often based on adverse effect profiles and patient-specific factors. In addition, dosing and titration are largely based on small studies and expert opinion with continuous electroencephalogram monitoring used to guide intensity and duration of treatment. Nonetheless, the doses required to halt seizure activity are likely to produce profound adverse effects that clinicians should anticipate and combat. The purpose of this review was to summarize the available RSE literature focusing on CIV midazolam, pentobarbital, propofol, and ketamine, and to serve as a primer for nurses providing care to these patients.

Should Barbiturates be Used in Refractory Status Epilepticus?

Status epilepticus (SE) is a frequent neurologic emergency, one third of patients do not respond to treatment with benzodiazepines followed by a second antiepileptic drug. While initial treatment of complex partial SE is accordant to that of generalized convulsive SE, further management of refractory SE depends on the risk for acute complications and long-term clinical consequences. These risks are low in complex partial SE; therefore, in this clinical form anesthetics commonly are not used. Generalized convulsive SE-even in its early course-is a potentially life-threatening condition; therefore, prompt use of anesthetics is urgently required. Drugs of choice are barbiturates, midazolam, and propofol, all of which exhibit specific advantages and disadvantages. Up to now, data from clinical studies do not allow to prefer or to discard one of these anesthetics, therefore also barbiturates still should be used in refractory SE. A widely accepted in-house protocol for the management of initial and refractory SE is highly recommended.

Can anesthetic treatment worsen outcome in status epilepticus?

Status epilepticus refractory to first-line and second-line antiepileptic treatments challenges neurologists and intensivists as mortality increases with treatment refractoriness and seizure duration. International guidelines advocate anesthetic drugs, such as continuously administered high-dose midazolam, propofol, and barbiturates, for the induction of therapeutic coma in patients with treatment-refractory status epilepticus. The seizure-suppressing effect of anesthetic drugs is believed to be so strong that some experts recommend using them after benzodiazepines have failed. Although the rationale for the use of anesthetic drugs in patients with treatment-refractory status epilepticus seems clear, the recommendation of their use in treating status epilepticus is based on expert opinions rather than on strong evidence. Randomized trials in this context are lacking, and recent studies provide disturbing results, as the administration of anesthetics was associated with poor outcome independent of possible confounders. This calls for caution in the straightforward use of anesthetics in treating status epilepticus. However, there are still more questions than answers, and current evidence for the adverse effects of anesthetic drugs in patients with status epilepticus remains too limited to advocate a change of treatment algorithms. In this overview, the rationale and the conflicting clinical implications of anesthetic drugs in patients with treatment-refractory status epilepticus are discussed, and remaining questions are elaborated. This article is part of a Special Issue entitled "Status Epilepticus".

Treatment of Generalized Convulsive Status Epilepticus in Pediatric Patients

Generalized convulsive status epilepticus (GCSE) is one of the most common neurologic emergencies and can be associated with significant morbidity and mortality if not treated promptly and aggressively. Management of GCSE is staged and generally involves the use of life support measures, identification and management of underlying causes, and rapid initiation of anticonvulsants. The purpose of this article is to review and evaluate published reports regarding the treatment of impending, established, refractory, and super-refractory GCSE in pediatric patients.

Refractory Convulsive Status Epilepticus in Children: Etiology, Associated Risk Factors and Outcome

OBJECTIVE

Refractory status epilepticus (RSE) is a life-threatening disease in children wherein the patient's convulsive seizures do not respond to adequate initial anticonvulsants. RSE is associated with high rate of mortality and morbidity. This study was aimed to survey the risk factors leading status epilepticus (SE) to RSE in children, and their early outcome.

MATERIALS & METHODS

Patients with SE hospitalized in Tabriz Children's Hospital, Iran were studied during the years 2007 and 2008 with regard to their clinical profile, etiology, the treatment methods available to them and their outcome upon release from the hospital.

RESULTS

Among 132 patients with SE, 53 patients (40.15%) suffered from RSE. Acute symptomatic etiology was a risk factor responsible for developing RSE in the patient (P=0.004). Encephalitis was the most common etiology of acute symptomatic SE. There was no significant relationship observed between RSE and the patients' age, gender, date of initial drug intake and type of seizure. The mortality rate was 8.3% and a new neurological deficit occurred in 25.7% of cases. None of RSE with encephalitis returned to the baseline status. Mortality and morbidity rates were significantly higher in children with RSE than in those with SE (P=0.006).

CONCLUSION

Etiology of SE significantly influenced prognosis of it with significant incidence of RSE in acute symptomatic group. Because acute neurological insult such as encephalitis and meningitis are common causes of RSE in children, properly management of them is necessary to avoid permanent brain damage.

Usefulness of intravenous lacosamide in status epilepticus

Lacosamide (LCM) is a treatment option for status epilepticus (SE) described in several series. We therefore proposed to describe its use in status epilepticus patients in our hospital. All patients admitted to our hospital for SE from September 2010 to April 2012 were evaluated. We collected related variables including the type of SE, etiology, antiepileptic drugs (AEDs) used, loading dose of AEDs, cessation of SE after AEDs, ICU admission and mortality. In those patients receiving LCM, we reviewed the infusion rate and time to response. We compared patients receiving LCM with patients in whom it was not used. This was a retrospective and uncontrolled study. A total of 92 patients were included; 67.7 % of SE patients who received LCM responded to treatment. The vast majority of the patients presented non-convulsive and motor focal SE. When we selected patients to receive four or more AEDs, the LCM efficacy was 55.6 %, a very similar result compared to when it was not used. Subsequently, we analyzed the sample regarding the AED administered as the second or third line of treatment, and the responder rate was significantly higher when LCM was used (84.6 vs. 47.8 %, p 0.041). After an adjusted regression analysis, the use of LCM was independently associated with cessation of SE. The total percentage of undesirable effects was very low (12 %), and they were all mild. No relationship was found between a specific etiology and better response. LCM is a useful drug that represents an alternative in the treatment of non-convulsive or focal motor SE. Its efficacy might be more important when it is administered as a second or third option after benzodiazepines. A randomized trial is required to confirm these results.

Midazolam fails to prevent neurological damage in children with convulsive refractory febrile status epilepticus

BACKGROUND

We conducted a retrospective study to compare the outcome of intravenous midazolam infusion without electroencephalography or targeted temperature management and barbiturate coma therapy with electroencephalography and targeted temperature management for treating convulsive refractory febrile status epilepticus.

PATIENTS

Of 49 consecutive convulsive refractory febrile status epilepticus patients admitted to the pediatric intensive care unit of our hospital, 29 were excluded because they received other treatments or because of various underlying illnesses. Thus, eight patients were treated with midazolam and 10 with barbiturate coma therapy using thiamylal. Midazolam-treated patients were intubated only when necessary, whereas barbiturate coma therapy patients were routinely intubated. Continuous electroencephalography monitoring was utilized only for the barbiturate coma group. The titration goal for anesthesia was clinical termination of status epilepticus in the midazolam group and suppression or burst-suppression patterns on electroencephalography in the barbiturate coma group. Normothermia was maintained using blankets and neuromuscular blockade in the barbiturate coma group and using antipyretics in the midazolam group. Prognoses were measured at 1 month after onset; children were classified into poor and good outcome groups.

RESULTS

Good outcome was achieved in all the barbiturate coma group patients and 50% of the midazolam group patients (P = 0.02, Fisher's exact test).

CONCLUSIONS

Although the sample size was small and our study could not determine which protocol element is essential for the neurological outcome, the findings suggest that clinical seizure control using midazolam without continuous electroencephalography monitoring or targeted temperature management is insufficient in preventing neurological damage in children with convulsive refractory febrile status epilepticus.

Management of pediatric status epilepticus

OPINION STATEMENT

Status epilepticus (SE) is a medical emergency consisting of persistent or recurring seizures without a return to baseline mental status. SE can be divided into subtypes based on seizure types and underlying etiologies. Management should be implemented rapidly and based on pre-determined care pathways. The aim is to terminate seizures while simultaneously identifying and managing precipitant conditions. Seizure management involves "emergent" treatment with benzodiazepines (lorazepam intravenously, midazolam intramuscularly, or diazepam rectally) followed by "urgent" therapy (phenytoin/fosphenytoin, phenobarbital, levetiracetam or valproate sodium). If seizures persist, "refractory" treatments include infusions of midazolam or pentobarbital. Prognosis is dependent on the underlying etiology and seizure persistence. This article reviews the current management strategies for pediatric convulsive SE.

Anesthetic drugs in status epilepticus: risk or rescue? A 6-year cohort study

OBJECTIVE

To evaluate the risks of continuously administered IV anesthetic drugs (IVADs) on the outcome of adult patients with status epilepticus (SE).

METHODS

All intensive care unit patients with SE from 2005 to 2011 at a tertiary academic medical care center were included. Relative risks were calculated for the primary outcome measures of seizure control, Glasgow Outcome Scale score at discharge, and death. Poisson regression models were used to control for possible confounders and to assess effect modification.

RESULTS

Of 171 patients, 37% were treated with IVADs. Mortality was 18%. Patients with anesthetic drugs had more infections during SE (43% vs 11%; p < 0.0001) and a 2.9-fold relative risk for death (2.88; 95% confidence interval 1.45-5.73), independent of possible confounders (i.e., duration and severity of SE, nonanesthetic third-line antiepileptic drugs, and critical medical conditions) and without significant effect modification by different grades of SE severity and etiologies. As IVADs were used after first- and second-line drugs failed, there was a correlation between treatment-refractory SE and the use of IVADs, leading to insignificant results regarding the risk of IVADs and outcome after additional adjustment for refractory SE.

CONCLUSION

Our findings heighten awareness regarding adverse effects of IVADs. Randomized controlled trials are needed to further clarify the association of IVADs with outcome in patients with SE.

CLASSIFICATION OF EVIDENCE

This study provides Class III evidence that patients with SE receiving IVADs have a higher proportion of infection and an increased risk of death as compared to patients not receiving IVADs.

Transient bradycardia induced by thiopentone sodium: a unique challenge in the management of refractory status epilepticus

Thiopentone sodium is one of the important drugs in the armamentarium for terminating refractory status epilepticus, a neurological emergency. We report a case of thiopentone-related bradycardia during the management of the new onset refractory status epilepticus in a young man, which was circumvented by prophylactic insertion of temporary pacemaker while thiopentone infusion was continued. A systematic approach was employed to manage the status epilepticus, including infusion of thiamine and glucose followed by antiepileptic drugs. The patient was ventilated and infused with lorazepam, phenytoin, sodium valproate, levetiracetam and midazolam followed by thiopentone sodium. With the introduction of thiopentone the seizures could be controlled but the patient developed severe bradycardia and junctional rhythm. The bradycardia disappeared when thiopentone was withdrawn and reappeared when the drug was reintroduced. Propofol infusion was tried with no respite in seizures. Later thiopentone sodium was reintroduced after inserting temporary cardiac pacemaker. Seizure was controlled and patient was weaned off the ventilator.

Safety and efficacy of intravenous lacosamide for adjunctive treatment of refractory status epilepticus: a comparative cohort study

BACKGROUND

Refractory status epilepticus (RSE) is an emergency with high mortality requiring neurointensive care. Treatment paradigms include first-generation antiepileptic drugs (AEDs) and anesthetics. Lacosamide (LCM) is a new AED, holding promise as a potent treatment option for RSE. High-level evidence regarding safety and efficacy in the treatment of RSE is lacking.

OBJECTIVE

The objective of the study was to evaluate the safety profile and efficacy of intravenous (i.v.) LCM as an add-on treatment in adult RSE patients.

METHODS

All consecutive RSE patients treated in the intensive care units (ICUs) of an academic tertiary care center between 2005 and 2011 were included. Severity of status epilepticus (SE) was graded by the SE Severity Scale (STESS), and SE etiology was categorized according to the guidelines of the International League Against Epilepsy (ILAE). Outcomes were seizure control, RSE duration, and death.

RESULTS

Of 111 RSE patients, 53 % were treated with LCM. Twenty-five patients with hypoxic-ischemic encephalopathy were excluded. Mortality was 30 %. Mean number of AEDs, duration, severity, and etiology of SE, as well as critical medical conditions did not differ between patients with and without LCM. While age tended to be higher, critical interventions, such as the use of anesthetics and mechanical ventilation, tended to be less frequent in patients with LCM. Seizure control tended to be achieved more frequently in patients with LCM (odds ratio, OR 2.34, 95 % CI 0.5-10.1, p = 0.252). Among patients with LCM, 51 % received LCM as the last AED (including hypoxic-ischemic encephalopathy), allowing the reasonable assumption that LCM was responsible for seizure control, which was achieved in 91 %. Multivariable analysis revealed a decreased mortality in patients with LCM (OR 0.34, 95 % CI 0.1-0.9, p = 0.035). A possible confounder in this context was the implementation of continuous video-electroencephalography (EEG) monitoring 6 months prior to the first use of i.v. LCM. There were no serious LCM-related adverse events.

CONCLUSION

LCM had a favorable safety profile as adjunctive treatment for RSE. Its use was associated with decreased mortality of RSE-a finding that might have been confounded by the implementation of continuous video-EEG monitoring in the ICU prior to the use of i.v. LCM, leading to heightened awareness as well as earlier diagnosis and treatment of SE. Randomized trials are warranted to further strengthen the evidence of efficacy of LCM for RSE treatment.

Problems and controversies in status epilepticus: a review and recommendations

Status epilepticus (SE) is a neurologic emergency that require immediate vigorous treatment in order to prevent serious morbidity or even death. Several investigators have suggested that the underlying etiology is the primary determinant of outcome. We believe that this may be true in aggressively treated SE, but not when the treatment is less than optimal. In this article, we will discuss the factors that have been implicated in affecting SE outcomes, and argue, on the basis of both human and experimental animal data, that aggressive treatment is necessary and appropriate for all presentations of SE in order to maximize the probability of a successful outcome even when the etiology suggests a poor prognosis.

Treatment of status epilepticus in a large community hospital

BACKGROUND

Status epilepticus (SE) is a neurological emergency usually requiring immediate medical treatment. Due to the lack of adequate studies, treatment guidelines and their application vary between countries and institutions. We intended to analyze current treatment of SE in a German community hospital.

METHODS

We retrospectively identified patients from a large community hospital in northern Germany who had been diagnosed with SE between August 2008 and December 2010. Their charts were reviewed regarding sociodemographic variables, treatment and outcome.

RESULTS

We studied the first SE episode in 172 patients with a median age of 69 years (range 18-90 years). The etiology was acute symptomatic in 30 patients, progressive symptomatic in 22 patients and remote symptomatic in 120 patients. Presentation was generalized convulsive in 60 patients, non-convulsive in 72 patients and simple motor/aura in 40 patients. Median latency from onset to treatment start was 0.75 h (range 0.2-336 h). Initial treatment had a success rate (SR) of 40%. Second line treatment had a success rate of 54%. In patients whose seizures were refractory to the first two drugs, success rates were between 31% and 55%, with only a minority of the patients receiving established drugs such as phenytoin or barbiturates. Multivariate analysis revealed non-convulsive semiology as the only factor significantly associated with refractoriness. SE could be terminated in 95% of the patients and in-hospital mortality was 10%. Benzodiazepines and phenytoin had the most severe side effects.

CONCLUSIONS

Status epilepticus can be terminated successfully and with low in-hospital mortality in the vast majority of the patients treated in a large community hospital. The success rate of each treatment step is between 30% and 55% regardless of the substances used.

The utility of EEG, SSEP, and other neurophysiologic tools to guide neurocritical care

Neuromonitoring is an emerging field that aims to characterize real-time neurophysiology to tailor therapy for acute injuries of the central nervous system. While cardiac telemetry has been used for decades among patients requiring critical care of all kinds, neurophysiology and neurotelemetry has only recently emerged as a routine screening tool in comatose patients. The increasing utilization of electroencephalography in comatose patients is primarily due to the recognition of the common occurrence of nonconvulsive seizures among comatose patients, the development of quantitative measures to detect regional ischemia, and the appreciation of electroencephalography phenotypes that indicate prognosis after cardiac arrest. Other neuromonitoring tools, such as somatosensory evoked potentials have a complementary role, surveying the integrity of the neuroaxis as an indicator of prognosis or illness progression in both acute brain and spinal injuries.

Treatment strategies for refractory status epilepticus

PURPOSE OF REVIEW

Status epilepticus is one of the most common emergencies in neurology, and every third patient does not respond to adequate first-line treatment. Refractory status epilepticus may be associated with increased morbidity and mortality, and new treatment options are urgently required. This review critically discusses recently published data regarding the role of 'new' antiepileptic drugs, the efficacy and safety of anesthetic agents, and the overall clinical outcome that is an integral part of treatment decisions.

RECENT FINDINGS

In complex partial status epilepticus, levetiracetam may be administered after failure of first-line and/or second-line agents. Lacosamide may be an interesting new adjunct, but reliable data are pending. In the treatment of refractory generalized convulsive status epilepticus, propofol seems to be as efficient as barbiturates. The latter are associated with prolonged ventilation times due to redistribution kinetics, whereas the former bears the risk of propofol infusion syndrome if administered continuously. Even after prolonged treatment with anesthetics over weeks, survival with satisfactory functional outcome is possible.

SUMMARY

Unambiguous recommendations regarding treatment strategies for refractory status epilepticus are limited by a lack of reliable data. Therefore, randomized controlled trials or at least prospective observational studies based on strict protocols incorporating long-term outcome data are urgently required.

Nonconvulsive status epilepticus: a diagnostic and therapeutic challenge in the intensive care setting

Nonconvulsive status epilepticus (NCSE) comprises a group of syndromes that display a great diversity regarding response to anticonvulsants ranging from virtually self-limiting variants to entirely refractory forms. Therefore, treatment on intensive care units (ICUs) is required only for a selection of cases. The aetiology and clinical form of NCSE are strong predictors for the overall prognosis. Absence status epilepticus is commonly seen in patients with idiopathic generalized epilepsy and is rapidly terminated by low-dose of benzodiazepines. The management of complex partial status epilepticus is straightforward in patients with pre-existing epilepsy, but poses major problems if occurring in the context of acute brain lesions. Subtle status epilepticus represents the late stage of undertreated previous overt generalized convulsive status epilepticus and always requires aggressive ICU treatment. Within the intensive care setting, the diagnostic challenge may be seen in the difficulty in delineating nonepileptic conditions such as posthypoxic, metabolic or septic encephalopathies from NCSE. Although all important forms are considered, the focus of this review lies on clinical presentations and electroencephalogram features of comatose patients treated on ICUs and possible diagnostic pitfalls.

A randomized trial for the treatment of refractory status epilepticus

BACKGROUND

Refractory status epilepticus (RSE) has a mortality of 16-39%; coma induction is advocated for its management, but no comparative study has been performed. We aimed to assess the effectiveness (RSE control, adverse events) of the first course of propofol versus barbiturates in the treatment of RSE.

METHODS

In this randomized, single blind, multi-center trial studying adults with RSE not due to cerebral anoxia, medications were titrated toward EEG burst-suppression for 36-48 h and then progressively weaned. The primary endpoint was the proportion of patients with RSE controlled after a first course of study medication; secondary endpoints included tolerability measures.

RESULTS

The trial was terminated after 3 years, with only 24 patients recruited of the 150 needed; 14 subjects received propofol, 9 barbiturates. The primary endpoint was reached in 43% in the propofol versus 22% in the barbiturates arm (P = 0.40). Mortality (43 vs. 34%; P = 1.00) and return to baseline clinical conditions at 3 months (36 vs. 44%; P = 1.00) were similar. While infections and arterial hypotension did not differ between groups, barbiturate use was associated with a significantly longer mechanical ventilation (P = 0.03). A non-fatal propofol infusion syndrome was detected in one patient, while one subject died of bowel ischemia after barbiturates.

DISCUSSION

Although undersampled, this trial shows significantly longer mechanical ventilation with barbiturates and the occurrence of severe treatment-related complications in both arms. We describe practical issues necessary for the success of future studies needed to improve the current unsatisfactory state of evidence.

Emergency EEG: study of survival

OBJECTIVE

To determine the survival rate according to the main findings of emergency electroencephalography (EEGs) of patients treated in a tertiary hospital.

METHOD

In this prospective study, the findings of consecutive emergency EEGs performed on inpatients in Hospital de Base in São José do Rio Preto, Brazil were correlated with survival utilizing Kaplan-Meyer survival curves.

RESULTS

A total of 681 patients with an average age of 42 years old (1 day to 96 years) were evaluated, of which 406 were male. The main reasons for EEGs were epileptic seizures (221 cases), hepatic encephalopathy [116 cases of which 85 (73.3%) were men, p-value=0.001], status epilepticus (104 cases) and impaired consciousness (78 cases). The underlying disease was confirmed in 578 (84.3%) cases with 119 (17.5%) having liver disease [91 (76.0%) were men, p-value=0.001], 105 (15.4%) suffering strokes, 67 (9.9%) having metabolic disorders, 51 (7.5%) central nervous system infections and 49 (7.2%) epilepsy. In the three months following EEG, a survival rate of 75% was found in patients with normal, discreet slow activity or intermittent rhythmic delta activity EEGs, of 50% for those with continuous delta activity and generalized epileptiform discharges, and of 25% for those with burst-suppression, diffuse depression, and in alpha/theta-pattern coma. Death was pronounced immediately in patients with isoelectric EEGs.

CONCLUSION

The main findings of EEGs, differentiated different survival rates and are thus a good prognostic tool for patients examined in emergencies.

Refractory status epilepticus: a prospective observational study

PURPOSE

Status epilepticus (SE) that is resistant to two antiepileptic compounds is defined as refractory status epilepticus (RSE). In the few available retrospective studies, estimated RSE frequency is between 31% and 43% of patients presenting an SE episode; almost all seem to require a coma induction for treatment. We prospectively assessed RSE frequency, clinical predictors, and outcome in a tertiary clinical setting.

METHODS

Over 2 years we collected 128 consecutive SE episodes (118 patients) in adults. Clinical data and their relationship to outcome (mortality and return to baseline clinical conditions) were analyzed.

RESULTS

Twenty-nine of 128 SE episodes (22.6%) were refractory to first- and second-line antiepileptic treatments. Severity of consciousness impairment and de novo episodes were independent predictors of RSE. RSE showed a worse outcome than non-RSE (39% vs. 11% for mortality; 21% vs. 63% for return to baseline clinical conditions). Only 12 patients with RSE (41%) required coma induction for treatment.

DISCUSSION

This prospective study identifies clinical factors predicting the onset of SE refractoriness. RSE appears to be less frequent than previously reported in retrospective studies; furthermore, most RSE episodes were treated outside the intensive care unit (ICU). Nonetheless, we confirm that RSE is characterized by high mortality and morbidity.

New treatment options in status epilepticus: a critical review on intravenous levetiracetam

The effectiveness of Levetiracetam (LEV) in the treatment of focal and generalised epilepsies is well established. LEV has a wide spectrum of action, good tolerability and a favourable pharmacokinetic profile. An injectable formulation has been released as an intravenous (IV) infusion in 2006 for patients with epilepsy when oral administration is temporarily not feasible. Bioequivalence to the oral preparation has been demonstrated with good tolerability and safety enabling a smooth transition from oral to parenteral formulation and vice versa. Although IV LEV is not licensed for treatment of status epilepticus (SE), open-label experience in retrospective case series is accumulating. Until now (August 2008) 156 patients who were treated with IV LEV for various forms of SE have been reported with an overall success rate of 65.4%. The most often used initial dose was 2000-3000 mg over 15 minutes. Adverse events were reported in 7.1%, and were mild and transient. Although IV LEV is an interesting alternative for the treatment of SE due to the lack of centrally depressive effects and low potential of drug interactions, one has to be aware of the nonrandomised retrospective study design, the heterogenous patient population and treatment protocols, and the publication bias inherent in these type of studies. Only a large randomised controlled trial with an adequate comparator will reveal the efficacy and effectiveness of this promising new IV formulation.

How I treat status epilepticus in the Neuro-ICU

Status epilepticus still remains a formidable adversary to neurointensivists. Although the majority of cases admitted to the Neuro-ICU are easily controlled with one or two antiepileptic drug defense lines, several cases become refractory and end up receiving general anesthetics for days or weeks with significant morbidity. Treatment algorithms have been published and should be followed, but in many cases they are inadequate because, especially in the distal branches of the treatment tree, are based on anecdotal data or small series of patients. In addition, a double-blind, randomized-controlled study in status has not been done for many years and solid data are lacking for the newer antiepileptics. Therefore, in the moderately to severely refractory cases, status treatment is based on personal previous experience and becomes an art more than a science. In this review of a difficult case, we discuss some fine details of the treatment provided and emphasize the multidisciplinary approach that should be followed including involvement of neurointensivists, epileptologists, electroencephalographers, and neurosurgeons.

Treatment of refractory status epilepticus: literature review and a proposed protocol

Refractory status epilepticus describes continuing seizures despite adequate initial pharmacologic treatment. This situation is common in children, but few data are available to guide management. We review the literature related to the pharmacologic treatment and overall management of refractory status epilepticus, including midazolam, pentobarbital, phenobarbital, propofol, inhaled anesthetics, ketamine, valproic acid, topiramate, levetiracetam, pyridoxine, corticosteroids, the ketogenic diet, and electroconvulsive therapy. Based on the available data, we present a sample treatment algorithm that emphasizes the need for rapid therapeutic intervention, employs consecutive medications with different mechanisms of action, and attempts to minimize the risk of hypotension. The initial steps suggest using benzodiazepines and phenytoin. Second steps suggest using levetiracetam or valproic acid, which exert few hemodynamic adverse effects and have multiple mechanisms of action. Additional management strategies that could be employed in tertiary-care settings, such as coma induction guided by continuous electroencephalogram monitoring and surgical options, are also discussed.

Effect of TTX suppression of hippocampal activity following status epilepticus

Status epilepticus (SE) is a severe neurological condition that can result in brain damage. In animals, SE is associated with cell loss and aberrant synaptogenesis. These pathological processes appear to be activity-dependent and may continue after the SE has ended. We postulated that suppression of electrical activity following SE at the site of the epileptic focus will reduce seizure-induced damage. To achieve this goal, tetrodotoxin (TTX) was used to suppress electrical activity in the hippocampi bilaterally following SE. Adult rats experienced lithium-pilocarpine-induced SE for 2h while controls underwent sham-SE with saline injections. Starting 12h after the SE or sham-SE rats received either continuous TTX (1 microM) or saline infusions through cannulas implanted in the bilateral hippocampi for 5h daily for 4 days. TTX resulted in significant EEG suppression and reduction in spikes and sharp waves. Rats were sacrificed 2 weeks after SE and the brains examined for cell loss and sprouting. Rats receiving TTX following SE had significantly more cell loss as well as a trend toward more mossy fiber sprouting than saline-treated rats following SE. TTX injection in sham-SE rats caused no cell loss or mossy fiber sprouting. These results suggest that suppression of electrical activity following SE is detrimental.