A comparison of four treatments for generalized convulsive status epilepticus. Veterans Affairs Status Epilepticus Cooperative Study Group

Randomized trial of lacosamide versus fosphenytoin for nonconvulsive seizures

OBJECTIVE

The optimal treatment of nonconvulsive seizures in critically ill patients is uncertain. We evaluated the comparative effectiveness of the antiseizure drugs lacosamide (LCM) and fosphenytoin (fPHT) in this population.

METHODS

The TRENdS (Treatment of Recurrent Electrographic Nonconvulsive Seizures) study was a noninferiority, prospective, multicenter, randomized treatment trial of patients diagnosed with nonconvulsive seizures (NCSs) by continuous electroencephalography (cEEG). Treatment was randomized to intravenous (IV) LCM 400mg or IV fPHT 20mg phenytoin equivalents/kg. The primary endpoint was absence of electrographic seizures for 24 hours as determined by 1 blinded EEG reviewer. The frequency with which NCS control was achieved in each arm was compared, and the 90% confidence interval (CI) was determined. Noninferiority of LCM to fPHT was to be concluded if the lower bound of the CI for relative risk was >0.8.

RESULTS

Seventy-four subjects were enrolled (37 LCM, 37 fPHT) between August 21, 2012 and December 20, 2013. The mean age was 63.6 years; 38 were women. Seizures were controlled in 19 of 30 (63.3%) subjects in the LCM arm and 16 of 32 (50%) subjects in the fPHT arm. LCM was noninferior to fPHT (p = 0.02), with a risk ratio of 1.27 (90% CI = 0.88-1.83). Treatment emergent adverse events (TEAEs) were similar in both arms, occurring in 9 of 35 (25.7%) LCM and 9 of 37 (24.3%) fPHT subjects (p = 1.0).

INTERPRETATION

LCM was noninferior to fPHT in controlling NCS, and TEAEs were comparable. LCM can be considered an alternative to fPHT in the treatment of NCSs detected on cEEG. Ann Neurol 2018;83:1174-1185.

Prevention, Treatment, and Monitoring of Seizures in the Intensive Care Unit

The diagnosis and management of seizures in the critically ill patient can sometimes present a unique challenge for practitioners due to lack of exposure and complex patient comorbidities. The reported incidence varies between 8% and 34% of critically ill patients, with many patients often showing no overt clinical signs of seizures. Outcomes in patients with unidentified seizure activity tend to be poor, and mortality significantly increases in those who have seizure activity longer than 30 min. Prompt diagnosis and provision of medical therapy are crucial in order to attain successful seizure termination and prevent poor outcomes. In this article, we review the epidemiology and pathophysiology of seizures in the critically ill, various seizure monitoring modalities, and recommended medical therapy.

Change in Mortality of Generalized Convulsive Status Epilepticus in High-Income Countries Over Time: A Systematic Review and Meta-analysis

Importance

Status epilepticus (SE) is associated with significant morbidity and mortality. Since the late 1990s, a more aggressive management of prolonged convulsive seizures lasting longer than 5 minutes has been advocated.

Objective

To determine if convulsive SE mortality has decreased during a time of increasing advocacy for out-of-hospital treatment and escalating and earlier treatment protocols for prolonged seizures and SE.

Data Source

This systemic review and meta-analysis on studies focused on the mortality of convulsive status epilepticus was conducted by searching MEDLINE, Embase, PsychINFO, CINAHL Plus, and the Cochrane Database of Systematic Reviews between January 1, 1990, and June 30, 2017.

Study Selection

Studies were excluded if they had fewer than 30 participants (<20 for refractory SE), were limited to SE of single specific etiology or an evaluation of a single treatment modality, or were studies of nonconvulsive SE.

Data Extraction and Synthesis

Data were abstracted and their quality was assessed via a modified Newcastle-Ottawa scale independently by 2 reviewers (A.N. and T.D.G.) using the Meta-analyses of Observational Studies in Epidemiology (MOOSE) guidelines. Data were pooled using a random-effects model.

Main Outcomes and Measures

The main outcome measure was in-hospital mortality or 30-day case fatality expressed as proportional mortality.

Results

Sixty-one studies were included in the analysis. The pooled mortality ratios were 15.9% (95% CI, 12.7-19.2) for adult studies, 13.0% (95% CI, 7.2-19.0) for all-age population studies, 3.6% (95% CI, 2.0%-5.2%) for pediatric studies, and 17.3% (95% CI, 9.8-24.7) for refractory SE studies, with very high between-study heterogeneity. We found no evidence of a change in prognosis over time nor by the definition of SE used.

Conclusions and Relevance

The mortality of convulsive SE is higher in adults than in children and there was no evidence for improved survival over time. Although there are many explanations for these findings, they can be explained by aetiology of SE being the major determinant of mortality. However, there are potential confounders, including differences in case ascertainment and study heterogeneity. This meta-analysis highlights the need for strict international guidelines for the study of this condition.

Status Epilepticus, Refractory Status Epilepticus, and Super-refractory Status Epilepticus

PURPOSE OF REVIEW

Status epilepticus, refractory status epilepticus, and super-refractory status epilepticus can be life-threatening conditions. This article presents an overview of the three conditions and discusses their management and outcomes.

RECENT FINDINGS

Status epilepticus was previously defined as lasting for 30 minutes or longer but now is more often defined as lasting 5 minutes or longer. A variety of potential causes exist for status epilepticus, refractory status epilepticus, and super-refractory status epilepticus, but all three ultimately involve changes at the cellular and molecular level. Management of patients with status epilepticus generally requires several studies, with EEG of utmost importance given the pathophysiologic changes that can occur during the course of status epilepticus. Status epilepticus is treated with benzodiazepines as first-line antiepileptic drugs, followed by phenytoin, valproic acid, or levetiracetam. If status epilepticus does not resolve, these are followed by an IV anesthetic and then alternative therapies based on limited data/evidence, such as repetitive transcranial magnetic stimulation, therapeutic hypothermia, immunomodulatory agents, and the ketogenic diet. Scores have been developed to help predict the outcome of status epilepticus. Neurologic injury and outcome seem to worsen as the duration of status epilepticus increases, with outcomes generally worse in super-refractory status epilepticus compared to status epilepticus and sometimes also to refractory status epilepticus.

SUMMARY

Status epilepticus can be a life-threatening condition associated with multiple complications, including death, and can progress to refractory status epilepticus and super-refractory status epilepticus. More studies are needed to delineate the best management of these three entities.

Levetiracetam versus phenytoin for second-line treatment of convulsive status epilepticus in children (ConSEPT): an open-label, multicentre, randomised controlled trial

BACKGROUND

Phenytoin is the current standard of care for second-line treatment of paediatric convulsive status epilepticus after failure of first-line benzodiazepines, but is only effective in 60% of cases and is associated with considerable adverse effects. A newer anticonvulsant, levetiracetam, can be given more quickly, is potentially more efficacious, and has a more tolerable adverse effect profile. We aimed to determine whether phenytoin or levetiracetam is the superior second-line treatment for paediatric convulsive status epilepticus.

METHODS

ConSEPT was an open-label, multicentre, randomised controlled trial conducted in 13 emergency departments in Australia and New Zealand. Children aged between 3 months and 16 years, with convulsive status epilepticus that failed first-line benzodiazepine treatment, were randomly assigned (1:1) using a computer-generated permuted block (block sizes 2 and 4) randomisation sequence, stratified by site and age (≤5 years, >5 years), to receive 20 mg/kg phenytoin (intravenous or intraosseous infusion over 20 min) or 40 mg/kg levetiracetam (intravenous or intraosseous infusion over 5 min). The primary outcome was clinical cessation of seizure activity 5 min after the completion of infusion of the study drug. Analysis was by intention to treat. This trial is registered with the Australian and New Zealand Clinical Trials Registry, number ACTRN12615000129583.

FINDINGS

Between March 19, 2015, and Nov 29, 2017, 639 children presented to participating emergency departments with convulsive status epilepticus; 127 were missed, and 278 did not meet eligibility criteria. The parents of one child declined to give consent, leaving 233 children (114 assigned to phenytoin and 119 assigned to levetiracetam) in the intention-to-treat population. Clinical cessation of seizure activity 5 min after completion of infusion of study drug occurred in 68 (60%) patients in the phenytoin group and 60 (50%) patients in the levetiracetam group (risk difference -9·2% [95% CI -21·9 to 3·5]; p=0·16). One participant in the phenytoin group died at 27 days because of haemorrhagic encephalitis; this death was not thought to be due to the study drug. There were no other serious adverse events.

INTERPRETATION

Levetiracetam is not superior to phenytoin for second-line management of paediatric convulsive status epilepticus.

FUNDING

Health Research Council of New Zealand, A+ Trust, Emergency Medicine Foundation, Townsville Hospital Private Practice Fund, Eric Ormond Baker Charitable Fund, and Princess Margaret Hospital Foundation.

A Comparison of Parenteral Phenobarbital vs. Parenteral Phenytoin as Second-Line Management for Pediatric Convulsive Status Epilepticus in a Resource-Limited Setting

Introduction: Pediatric convulsive status epilepticus (CSE) which is refractory to first-line benzodiazepines is a significant clinical challenge, especially within resource-limited countries. Parenteral phenobarbital is widely used in Africa as second-line agent for pediatric CSE, however evidence to support its use is limited. Purpose: This study aimed to compare the use of parenteral phenobarbital against parenteral phenytoin as a second-line agent in the management of pediatric CSE. Methodology: An open-labeled single-center randomized parallel clinical trial was undertaken which included all children (between ages of 1 month and 15 years) who presented with CSE. Children were allocated to receive either parenteral phenobarbital or parenteral phenytoin if they did not respond to first-line benzodiazepines. An intention-to-treat analysis was performed with the investigators blinded to the treatment arms. The primary outcome measure was the success of terminating CSE. Secondary outcomes included the need for admission to the pediatric intensive care unit (PICU) and breakthrough seizures during the admission. In addition, local epidemiological data was collected on the burden of pediatric CSE. Results: Between 2015 and 2018, 193 episodes of CSE from 111 children were enrolled in the study of which 144 met the study requirements. Forty-two percent had a prior history of epilepsy mostly from structural brain pathology (53%). The most common presentation was generalized CSE (65%) caused by acute injuries or infections of the central nervous system (59%), with 19% of children having febrile status epilepticus. Thirty-five percent of children required second-line management. More patients who received parenteral phenobarbital were at a significantly reduced risk of failing second-line treatment compared to those who received parenteral phenytoin (RR = 0.3, p = 0.0003). Phenobarbital also terminated refractory CSE faster (p < 0.0001). Furthermore, patients who received parenteral phenobarbital were less likely to need admission to the PICU. There was no difference between the two groups in the number of breakthrough seizures that occurred during admission. Conclusion: Overall this study supports anecdotal evidence that phenobarbital is a safe and effective second-line treatment for the management of pediatric CSE. These results advocate for parenteral phenobarbital to remain available to health care providers managing pediatric CSE in resource-limited settings. Attachments: CONSORT 2010 checklist Trial registration: NCT03650270 Full trial protocol available: https://clinicaltrials.gov/ct2/show/NCT03650270?recrs=e&type=Intr&cond=Status+Epilepticus&age=0&rank=1.

Meta-analysis and cost-effectiveness of second-line antiepileptic drugs for status epilepticus

Objective

Compare the cost and effectiveness of nonbenzodiazepine antiepileptic drugs (non-BZD AEDs) for treatment of BZD-resistant convulsive status epilepticus (SE).

Methods

Decision analysis model populated with effectiveness data from a systematic review and meta-analysis of the literature, and cost data from publicly available prices. The primary outcome was cost per seizure stopped ($/SS). Sensitivity analyses evaluated the robustness of the results across a wide variation of the input parameters.

Results

We included 24 studies with 1,185 SE episodes. The most effective non-BZD AED was phenobarbital (PB) with a probability of SS of 0.8 (95% confidence interval [CI]: 0.69–0.88), followed by valproate (VPA) (0.71 [95% CI: 0.61–0.79]), lacosamide (0.66 [95% CI: 0.51–0.79]), levetiracetam (LEV) (0.62 [95% CI: 0.5–0.73]), and phenytoin/fosphenytoin (PHT) (0.53 [95% CI: 0.39–0.67]). In pairwise comparisons, PB was more effective than PHT (p = 0.002), VPA was more effective than PHT (p = 0.043), and PB was more effective than LEV (p = 0.018). The most cost-effective non-BZD AED was LEV (incremental cost-effectiveness ratio [ICER]: $18.55/SS), followed by VPA (ICER: $94.44/SS), and lastly PB (ICER: $847.22/SS). PHT and lacosamide were not cost-effective compared to the other options. Sensitivity analyses showed marked overlap in cost-effectiveness, but PHT was consistently less cost-effective than LEV, VPA, and PB.

Conclusion

VPA and PB were more effective than PHT for SE. There is substantial overlap in the cost-effectiveness of non-BZD AEDs for SE, but available evidence does not support the preeminence of PHT, neither in terms of effectiveness nor in terms of cost-effectiveness.

[Diagnosis and treatment of status epilepticus in the intensive care unit]

Both convulsive and nonconvulsive status epilepticus are associated with a high risk of morbidity and mortality. To limit brain damage, emergency investigation of etiology and treatment must be done synchronously. This review presents the general rules for treatment. The steps of pharmacologic escalation with benzodiazepines, antiepileptics, and anesthetics are discussed together with their advantages and disadvantages.

Pharmacotherapy for Refractory and Super-Refractory Status Epilepticus in Adults

Patients with prolonged seizures that do not respond to intravenous benzodiazepines and a second-line anticonvulsant suffer from refractory status epilepticus and those with seizures that do not respond to continuous intravenous anesthetic anticonvulsants suffer from super-refractory status epilepticus. Both conditions are associated with significant morbidity and mortality. A strict pharmacological treatment regimen is urgently required, but the level of evidence for the available drugs is very low. Refractory complex focal status epilepticus generally does not require anesthetics, but all intravenous non-anesthetizing anticonvulsants may be used. Most descriptive data are available for levetiracetam, phenytoin and valproate. Refractory generalized convulsive status epilepticus is a life-threatening emergency, and long-term clinical consequences are eminent. Administration of intravenous anesthetics is mandatory, and drugs acting at the inhibitory gamma-aminobutyric acid (GABA)_A receptor such as midazolam, propofol and thiopental/pentobarbital are recommended without preference for one of those. One in five patients with anesthetic treatment does not respond and has super-refractory status epilepticus. With sustained seizure activity, excitatory N-methyl-d-aspartate (NMDA) receptors are increasingly expressed post-synaptically. Ketamine is an antagonist at this receptor and may prove efficient in some patients at later stages. Neurosteroids such as allopregnanolone increase sensitivity at GABA_A receptors; a Phase 1/2 trial demonstrated safety and tolerability, but randomized controlled data failed to demonstrate efficacy. Adjunct ketogenic diet may contribute to termination of difficult-to-treat status epilepticus. Randomized controlled trials are needed to increase evidence for treatment of refractory and super-refractory status epilepticus, but there are multiple obstacles for realization. Hitherto, prospective multicenter registries for pharmacological treatment may help to improve our knowledge.

Intravenous use of valproic acid in status epilepticus is associated with high risk of hyperammonemia

PURPOSE

The aim of the study was to examine the frequency of hyperammonemia secondary to valproic acid treatment in status epilepticus and to describe the characteristics of the patients.

METHODS

All patients with established status epilepticus during 2014 to 2016 at Ryhov County Hospital were identified in a retrospective case series. Clinical and laboratory findings were collected from electronic medical files and the Metavision database at the intensive care unit (ICU). Hyperammonemia was defined as a concentration of at least 50 μmol/L.

RESULTS

11 of 40 patients developed hyperammonemia. These patients had a significantly longer stay at the ICU (12.6 vs 2.5 days) and at the hospital (22 vs 11 days). All patients with hyperammonemia were treated at the ICU and all received antibiotics. 12 patients were treated with intravenous valproic acid outside the ICU. Hyperammonemia was not related to Body Mass Index, time to initiation of therapy or laboratory abnormalities except anemia (Hemoglobin 104 vs 122 g/l). There was no difference in mortality between groups.

CONCLUSION

The risk of hyperammonemia is almost 40% in patients receiving intravenous valproic acid in the ICU setting. The underlying mechanisms are probably either individual susceptibility or high metabolic demands. A high vigilance should be recommended. These data require further research via prospective designs in which multiple variables are controlled to explore the effects of individual factors on treatment outcome.

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.

Intravenous Corticosteroids as an Adjunctive Treatment for Refractory and Super-Refractory Status Epilepticus: An Observational Cohort Study

INTRODUCTION

Status epilepticus (SE) represents a neurological emergency that leads to considerable morbidity and mortality. Following failure of first-line therapy, usually with benzodiazepines, there is no clear evidence to guide treatment of refractory SE, although a wide variety of approaches has been described anecdotally.

OBJECTIVE

The aim of this study was to assess the clinical response to corticosteroids in adults with refractory and super-refractory SE, describing, to the best of our knowledge, the first adult SE cohort treated with corticosteroids.

METHODS

We retrospectively analysed our adult SE registry (2006-2017), identifying 15 out of 987 episodes (1.5%) in which corticosteroids were prescribed de novo as adjuvant therapy to a variety of antiepileptic drug regimens. We analysed incident episodes and defined clinical response as SE ceasing within 1 week of administration, without any other medical intervention.

RESULTS

Out of 987 SE episodes, 15 (1.5%) were treated with de novo corticosteroids, corresponding to 12 patients, with increasing prevalence as the SE became refractory (10/411; 2.4% of episodes) and super-refractory (5/108; 4.6% of episodes). One patient (a woman with Rasmussen encephalitis) presented with four SE episodes over a period of 3 years, so only her index SE episode was included in subsequent analyses. The episodes treated were predominantly of inflammatory origin (6/12), such as autoimmune or Rasmussen encephalitis. In five out of 12 (42%) of the considered incident episodes, SE resolved following corticosteroids (all within 3 days). The outcome was better in this responders group (for 2/5 episodes, patients did not have a new handicap at discharge, versus 0/7 in non-responders). In patients with inflammatory and acute symptomatic causes, global prognosis was better than in those with progressive or neurodegenerative aetiologies (6/8 vs. 4/4 had a new handicap at discharge or died).

CONCLUSIONS

Our observations seem to support the use of corticosteroids, especially for acute SE of putative inflammatory origin; these compounds, however, were prescribed infrequently.

Comparing the efficacy of sodium valproate and levetiracetam following initial lorazepam in elderly patients with generalized convulsive status epilepticus (GCSE): A prospective randomized controlled pilot study

PURPOSE

This randomized control study was conducted to compare the efficacy of sodium valproate (SVP) and levetiracetam (LEV) following initial intravenous lorazepam in elderly patients (age: >60years) with generalized convulsive status epilepticus (GCSE) and to identify predictors of poor seizure control.

METHODS

A total of 118 patients (mean age: 67.5 ± 7.5 years, M:F = 1.6:1), who had presented with GCSE were randomized into the SVP or LEV treatment arms. All patients received initial intravenous lorazepam (0.1 mg/kg) followed by one of the two antiepileptic drugs (AEDs), parenteral SVP (20-25 mg/kg) or LEV (20-25 mg/kg). Those who failed to achieve control with the initial AED, were crossed over to receive the other AED. One-hundred patients (SVP = 50; LEV = 50) completed the study.

RESULTS

SE could be controlled with lorazepam and one of the AEDs (SVP or LEV) in 71.18% (84/118). Intention-to-treat analysis showed that the two groups did not differ significantly in terms of seizure control [SVP: 41/60 (68.3%); LEV: 43/58 (74.1%), p = 0.486]. Of 100 patients who completed the study, seizure control was achieved in 38/50(76%) in the SVP and 43/50(86%) in the LEV group (p = 0.202). After crossing over to the second AED, SE could be controlled in an additional in 50% (6/12) in SVP (+LEV) group and in 14.3% (1/7) in LEV (+SVP) group. Overall, after the second AED, seizure control was achieved in 77.1% (91/118). Higher STESS was associated with poor therapeutic response (p = 0.049).

CONCLUSIONS

The efficacy of SVP and LEV following initial lorazepam in controlling GCSE in elderly population was comparable, hence the choice of AED could be individualized.

Seizure-Induced Potentiation of AMPA Receptor-Mediated Synaptic Transmission in the Entorhinal Cortex

Excessive excitation is considered one of the key mechanisms underlying epileptic seizures. We investigated changes in the evoked postsynaptic responses of medial entorhinal cortex (ERC) pyramidal neurons by seizure-like events (SLEs), using the modified 4-aminopyridine (4-AP) model of epileptiform activity. Rat brain slices were perfused with pro-epileptic solution contained 4-AP and elevated potassium and reduced magnesium concentration. We demonstrated that 15-min robust epileptiform activity in slices leads to an increase in the amplitude of α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor (AMPAR)-mediated component of the evoked response, as well as an increase in the polysynaptic γ-aminobutyric acid (GABA) and N-methyl-D-aspartate (NMDA) receptor-mediated components. The increase in AMPA-mediated postsynaptic conductance depends on NMDA receptor activation. It persists for at least 15 min after the cessation of SLEs and is partly attributed to the inclusion of calcium-permeable AMPA receptors in the postsynaptic membrane. The mathematical modeling of the evoked responses using the conductance-based refractory density (CBRD) approach indicated that such augmentation of the AMPA receptor function and depolarization by GABA receptors results in prolonged firing that explains the increase in polysynaptic components, which contribute to overall network excitability. Taken together, our data suggest that AMPA receptor enhancement could be a critical determinant of sustained status epilepticus (SE).

Critical Care in the Pediatric Emergency Department

In caring for critically ill children, recognition and management often begins in the pediatric emergency department. A seamless transition in care is needed to ensure appropriate care to the sickest of children. This review covers the management of critically ill children in the pediatric emergency department beyond the initial stabilization for conditions such as acute respiratory failure and pediatric acute respiratory distress syndrome, traumatic brain injury, status epilepticus, congenital heart disease, and metabolic emergencies.

Impact of timing of continuous intravenous anesthetic drug treatment on outcome in refractory status epilepticus

Background

Patients in refractory status epilepticus (RSE) may require treatment with continuous intravenous anesthetic drugs (cIVADs) for seizure control. The use of cIVADs, however, was recently associated with poor outcome in status epilepticus (SE), raising the question of whether cIVAD therapy should be delayed for attempts to halt seizures with repeated non-anesthetic antiepileptic drugs. In this study, we aimed to determine the impact of differences in therapeutic approaches on RSE outcome using timing of cIVAD therapy as a surrogate for treatment aggressiveness.

Methods

This was a retrospective cohort study over 14 years (n = 77) comparing patients with RSE treated with cIVADs within and after 48 h after RSE onset, and functional status at last follow-up was the primary outcome (good = return to premorbid baseline or modified Rankin Scale score of less than 3). Secondary outcomes included discharge functional status, in-hospital mortality, RSE termination, induction of burst suppression, use of thiopental, duration of RSE after initiation of cIVADs, duration of mechanical ventilation, and occurrence of super-refractory SE. Analysis was performed on the total cohort and on subgroups defined by RSE severity according to the Status Epilepticus Severity Score (STESS) and by the variables contained therein.

Results

Fifty-three (68.8%) patients received cIVADs within the first 48 h. Early cIVAD treatment was independently associated with good outcome (adjusted risk ratio [aRR] 3.175, 95% confidence interval [CI] 1.273–7.918; P = 0.013) as well as lower chance of both induction of burst suppression (aRR 0.661, 95% CI 0.507–0.861; P = 0.002) and use of thiopental (aRR 0.446, 95% CI 0.205–0.874; P = 0.043). RSE duration after cIVAD initiation was shorter in the early cIVAD cohort (hazard ratio 1.796, 95% CI 1.047–3.081; P = 0.033). Timing of cIVAD use did not impact the remaining secondary outcomes. Subgroup analysis revealed early cIVAD impact on the primary outcome to be driven by patients with STESS of less than 3.

Conclusions

Patients with RSE treated with cIVADs may benefit from early initiation of such therapy.

Electronic supplementary material

The online version of this article (10.1186/s13054-018-2235-2) contains supplementary material, which is available to authorized users.

Potentiating KCC2 activity is sufficient to limit the onset and severity of seizures

The type 2 K+/Cl- cotransporter (KCC2) allows neurons to maintain low intracellular levels of Cl-, a prerequisite for efficient synaptic inhibition. Reductions in KCC2 activity are evident in epilepsy; however, whether these deficits directly contribute to the underlying pathophysiology remains controversial. To address this issue, we created knock-in mice in which threonines 906 and 1007 within KCC2 have been mutated to alanines (KCC2-T906A/T1007A), which prevents its phospho-dependent inactivation. The respective mice appeared normal and did not show any overt phenotypes, and basal neuronal excitability was unaffected. KCC2-T906A/T1007A mice exhibited increased basal neuronal Cl- extrusion, without altering total or plasma membrane accumulation of KCC2. Critically, activity-induced deficits in synaptic inhibition were reduced in the mutant mice. Consistent with this, enhanced KCC2 was sufficient to limit chemoconvulsant-induced epileptiform activity. Furthermore, this increase in KCC2 function mitigated induction of aberrant high-frequency activity during seizures, highlighting depolarizing GABA as a key contributor to the pathological neuronal synchronization seen in epilepsy. Thus, our results demonstrate that potentiating KCC2 represents a therapeutic strategy to alleviate seizures.

Status epilepticus in the elderly

Children and the elderly (≥60 years of age) have the highest incidence of status epilepticus (SE). Because of their general health, elderly individuals are much more likely than younger (<60 years of age) persons to have more severe consequences from seizures. The incidence of SE is 15.5/100 000 in the 60-69 age group, 21.5/100 000 in the 70-79 age group and 25.9/100 000 in persons 80 and older. The most common cause in the elderly is acute symptomatic, with stroke and hypoxia the most frequent. The overall mortality of SE is quite high and occurs early, often within the first few days, and is related to the cause, with mortality of more than 80% in persons with anoxia. Although the cause of SE is an important factor in mortality, the aging body and brain may contribute to an unfavorable outcome. Treatment in the elderly is essentially the same as in younger adults with benzodiazepines (lorazepam, diazepam, clonazepam) and longer acting antiseizure drugs (phenytoin, fosphenytoin, valproate, levetiracetam, and lacosamide. At this time there are no evidence-based studies regarding Axis 2 (etiology) and Axis 4 (age). All current interventions for SE involve antiseizure drugs that were developed for treatment of chronic epilepsy. Treatments should be developed that are more specific for the various etiologies and involve drugs that work on the underlying cause of the SE.

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.

Novel drugs and early polypharmacotherapy in status epilepticus

PURPOSE

Rescue medications for status epilepticus (SE) have a relatively high rate of failure. The purpose of this review is to summarize the evidence for the efficacy of novel drugs and early polypharmacotherapy for SE.

METHOD

Literature review.

RESULTS

New drugs and treatment strategies aim to target the pathophysiology of SE in order to improve seizure control and outcomes. Changes at the synapse level during SE include a progressive decrease in synaptic GABA_A receptors and increase in synaptic NMDA receptors. These changes tend to promote self-sustaining seizures. Current SE guidelines recommend a rapid stepwise treatment using benzodiazepines in monotherapy as the first-line treatment, targeting GABA_A synaptic receptors. Novel treatment approaches target GABA_A synaptic and extrasynaptic receptors with allopregnanolone, and NMDA receptors with ketamine. Novel rescue treatments used for SE include topiramate, brivaracetam, and perampanel, which are already marketed in epilepsy. Some available drugs not marketed for use in epilepsy have been used in the treatment of SE, and other agents are being studied for this purpose. Early polytherapy, most frequently combining a benzodiazepine with a second-line drug or an NMDA receptor antagonist, might potentially increase seizure control with relatively minor increase in side effects. Although many preclinical studies support novel drugs and early polytherapy in SE, human studies are scarce and inconclusive. Currently, evidence is lacking to recommend specific combinations of these new agents.

CONCLUSIONS

Novel drugs and strategies target the underlying pathophysiology of SE with the intent to improve seizure control and outcomes.

Pathophysiology of convulsive status epilepticus

PURPOSE

To summarize the pathophysiology of convulsive status epilepticus (SE) with a focus on practical implications for treatment.

METHOD

Narrative review of the medical literature on the pathophysiology of convulsive SE. We considered both animal models of SE and clinical studies.

RESULTS

Convulsive SE is an emergency in which prolonged convulsive seizures are associated with cardiorespiratory instability, hypoxia, hypoglycemia, and hyperthermia. Supportive treatment helps correct these physiological imbalances. When treatment is delayed, the ability of first line seizure suppressing medications to terminate the seizure can be reduced. Animal studies have suggested that GABA_A receptor trafficking may contribute to the failure of the first line therapies and that NMDA receptor antagonists such as ketamine may become more effective as seizures last longer. Potential strategies to take advantage of these changes in pathophysiology include a rapid escalation from benzodiazepines to non-benzodiazepine antiepileptic drugs (AEDs), early polytherapy and use of NMDA antagonists such as ketamine for refractory convulsive SE. Despite the importance of a timely treatment of convulsive SE, major treatment delays are frequent in clinical practice. Policies to improve time to treatment, especially in convulsive SE that starts outside the hospital, may improve response to treatment and convulsive SE outcomes.

CONCLUSIONS

Convulsive SE is a time-sensitive emergency in which the underlying pathophysiology may provide targets for improving treatment strategies. A timely transition from benzodiazepines to other AEDs may help reduce treatment resistance in convulsive SE.

Use of Emergency Medication in Adult Patients with Epilepsy: A Multicentre Cohort Study from Germany

BACKGROUND

Emergency treatment with benzodiazepines is indicated in prolonged seizures, seizure clusters and status epilepticus.

OBJECTIVE

The aim of this study was to evaluate the use of emergency medication in adult patients with epilepsy.

PATIENTS AND METHODS

All adult epilepsy patients attending the epilepsy outpatient clinics of the university hospitals in Frankfurt and Marburg in 2015 were asked to participate in this questionnaire-based, retrospective survey.

RESULTS

A total of 481 patients with a mean age of 43.4 years (range 18-94 years, 54% female) participated in the study. Among them, 134 patients (27.9%) reported on the prescription of an emergency medication during the last year. Patients receiving emergency medication were younger and exhibited a lower age at epilepsy onset, a higher seizure frequency and a higher number of regularly taken antiepileptic drugs. The most frequently taken emergency drugs were oral lorazepam tablets (65.7%; n = 88 out of 134), followed by buccal midazolam (23.9%, n = 32) and rectal diazepam (17.9%, n = 24). The most common indications for administering the emergency medication were seizures continuing for several minutes (35.1%, n = 47), but almost the same number of patients (33.6%, n = 45) stated that the rescue medication was given during or after every seizure. Regarding adverse events, sedation was named as a major (18.7%, n = 25) or moderate (29.1%; n = 39) problem by a substantial number of patients. Difficulties in administration were reported by 17 (13%) patients. Two-thirds assessed the efficacy of their emergency medication as good (50.7%, n = 68) or as very good (15.7%, n = 21). For multivariate logistic regression analysis, aspects such as young age at onset, active epilepsy, structural etiology, presence of generalised tonic-clonic seizures, past medical history of status epilepticus and living with another person independently predicted prescription of emergency medication.

CONCLUSIONS

In most cases, unsuitable benzodiazepines with slow absorption due to oral administration were prescribed, or buccal midazolam solution was used off-label in adults. Furthermore, inappropriate use of emergency medication at every seizure was reported by a substantial number of participating patients.

Decreasing Seizure Treatment Time Through Quality Improvement Reduces Critical Care Utilization

BACKGROUND

Rapid, effective treatment for status epilepticus reduces associated morbidity and mortality, yet medication delivery remains slow in many hospitalized patients. We utilized quality improvement (QI) methodology to improve treatment times for hospitalized children with status epilepticus. We hypothesized rapid initial seizure treatment would decrease seizure morbidity.

METHODS

We utilized QI and statistical process control analysis in a nonintensive care setting within a tertiary care pediatric hospital. We performed Plan-Do-Study-Act cycles including (1) revising the nursing process for responding to seizures, (2) emphasizing intranasal midazolam over intravenous lorazepam, (3) relocating medications and supplies, (4) developing documentation tools and reinforcing correct processes, (5) developing and disseminating an online education module for residents and nurse practitioners, and (6) completing standardization to intranasal midazolam.

RESULTS

Seventeen months after starting the project, 66 seizures had been treated with a benzodiazepine in a median (p₂₅-p₇₅) time of 7.5 minutes (5 to 10), decreased from a baseline of 14 minutes (8-30) (P = 0.01). The proportion of patients receiving a benzodiazepine in 10 minutes or less improved from 39% to 79%. The proportion of patients transferred to intensive care decreased from a baseline of 39% to 9% (P < 0.005), resulting in an estimated $2.1 million in mitigated hospital charges. Significant harm did not occur during the implementation of these interventions.

CONCLUSIONS

Children with status epilepticus were treated with benzodiazepines more rapidly and effectively following implementation of QI methodology. These interventions reduced utilization of critical care and mitigated hospital charges.

Perampanel but Not Amantadine Prevents Behavioral Alterations and Epileptogenesis in Pilocarpine Rat Model of Status Epilepticus

Pilocarpine-induced status epilepticus (SE), which results in the development of spontaneous recurrent seizures (SRSs) activates glutamatergic receptors that contribute to seizure sustenance and neuronal cell death. In the current study, we evaluate whether the exposure to perampanel, an α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor blocker, or amantadine, a N-methyl-D-aspartic acid (NMDA) receptor blocker would reduce the SE-induced long-term consequences. SE was induced in adult male Sprague Dawley rats with pilocarpine. Perampanel or amantadine was injected 10 or 60 min after SE onset. The efficacy of either, in overcoming pilocarpine-induced SE was assessed using electroencephalogram (EEG) recordings. In addition, alterations in cognitive function, development of spontaneous recurrent seizures (SRSs), and hippocampal damage that are generally encountered after SE were also assessed at 72 h and 5 weeks after the induction of SE. Our results indicate that both early and late treatment with perampanel but not amantadine significantly reduced seizure activity. Furthermore, perampanel but not amantadine, reversed the memory deficits in Y-maze and novel object recognition (NOR) tests and retarded the appearance of SRSs. Moreover, perampanel treatment led to reduced SE-induced caspase-3 activation in the hippocampal lysates. Taken together, the data obtained from the study reveals that blocking AMPA receptors by perampanel can modify SE-induced long-term consequences. Our results may provide a proof of principle for the potential therapeutic application of perampanel in clinical use for status epilepticus in future.

Emergency Neurological Life Support: Status Epilepticus

Patients with prolonged or rapidly recurring convulsions lasting more than 5 min should be considered to be in status epilepticus (SE) and receive immediate resuscitation. Although there are few randomized clinical trials, available evidence and experience suggest that early and aggressive treatment of SE improves patient outcomes, for which reason this was chosen as an Emergency Neurological Life Support protocol. The current approach to the emergency treatment of SE emphasizes rapid initiation of adequate doses of first line therapy, as well as accelerated second line anticonvulsant drugs and induced coma when these fail, coupled with admission to a unit capable of neurological critical care and electroencephalography monitoring. This protocol will focus on the initial treatment of SE but also review subsequent steps in the protocol once the patient is hospitalized.

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.

Convulsive status epilepticus management in adults and children: Report of the Working Group of the Polish Society of Epileptology

INTRODUCTION

The Working Group was established at the initiative of the General Board of the Polish Society of Epileptology (PSE) to develop an expert position on the treatment of convulsive status epilepticus (SE) in adults and children in Poland. Generalized convulsive SE is the most common form and also represents the greatest threat to life, highlighting the importance of the choice of appropriate therapeutic treatment.

AIM OF GUIDELINE

We present the therapeutic options separately for treatment during the early preclinical (>5-30min), established (30-60min), and refractory (>60min) SE phases. This division is based on time and response to AEDs, and indicates a practical approach based on pathophysiological data.

RESULTS

Benzodiazepines (BZD) are the first-line drugs. In cases of ineffective first-line treatment and persistence of the seizure, the use of second-line treatment: phenytoin, valproic acid or phenobarbital is required. SE that persists after the administration of benzodiazepines and phenytoin or another second-line AED at appropriate doses is defined as refractory and drug resistant and requires treatment in the intensive care unit (ICU). EEG monitoring is essential during therapy at this stage. Anesthesia is typically continued for an initial period of 24h followed by a slow reversal and is re-established if seizures recur. Anesthesia is usually administered either to the level of the "burst suppression pattern" or to obtain the "EEG suppression" pattern.

CONCLUSIONS

Experts agree that close and early cooperation with a neurologist and anesthetist aiming to reduce the risk of pharmacoresistant cases is an extremely important factor in the treatment of patients with SE. This report has educational, practical and organizational aspects, outlining a standard plan for SE management in Poland that will improve therapeutic efficacy.

Antiepileptic drugs in critically ill patients

BACKGROUND

The incidence of seizures in intensive care units ranges from 3.3% to 34%. It is therefore often necessary to initiate or continue anticonvulsant drugs in this setting. When a new anticonvulsant is initiated, drug factors, such as onset of action and side effects, and patient factors, such as age, renal, and hepatic function, should be taken into account. It is important to note that the altered physiology of critically ill patients as well as pharmacological and nonpharmacological interventions such as renal replacement therapy, extracorporeal membrane oxygenation, and target temperature management may lead to therapeutic failure or toxicity. This may be even more challenging with the availability of newer antiepileptics where the evidence for their use in critically ill patients is limited.

MAIN BODY

This article reviews the pharmacokinetics and pharmacodynamics of antiepileptics as well as application of these principles when dosing antiepileptics and monitoring serum levels in critically ill patients. The selection of the most appropriate anticonvulsant to treat seizure and status epileptics as well as the prophylactic use of these agents in this setting are also discussed. Drug-drug interactions and the effect of nonpharmacological interventions such as renal replacement therapy, plasma exchange, and extracorporeal membrane oxygenation on anticonvulsant removal are also included.

CONCLUSION

Optimal management of antiepileptic drugs in the intensive care unit is challenging given altered physiology, polypharmacy, and nonpharmacological interventions, and requires a multidisciplinary approach where appropriate and timely assessment, diagnosis, treatment, and monitoring plans are in place.

Astroglial role in the pathophysiology of status epilepticus: an overview

Status epilepticus is a medical emergency with elevated morbidity and mortality rates, and represents a leading cause of epilepsy-related deaths. Though status epilepticus can occur at any age, it manifests more likely in children and elderly people. Despite the common prevalence of epileptic disorders, a complete explanation for the mechanisms leading to development of self-limited or long lasting seizures (as in status epilepticus) are still lacking. Apart from neurons, research evidence suggests the involvement of immune and glial cells in epileptogenesis. Among glial cells, astrocytes represent an ideal target for the study of the pathophysiology of status epilepticus, due to their key role in homeostatic balance of the central nervous system. During status epilepticus, astroglial cells are activated by the presence of cytokines, damage associated molecular patterns and reactive oxygen species. The persistent activation of astrocytes leads to a decrease in glutamate clearance with a corresponding accumulation in the synaptic extracellular space, increasing the chance of neuronal excitotoxicity. Moreover, major alterations in astrocytic gap junction coupling, inflammation and receptor expression, facilitate the generation of seizures. Astrocytes are also involved in dysregulation of inhibitory transmission in the central nervous system and directly participate in ionic homeostatic alterations during status epilepticus. In the present review, we focus on the functional and structural changes in astrocytic activity that participate in the development and maintenance of status epilepticus, with special attention on concurrent inflammatory alterations. We also include potential astrocytic treatment targets for status epilepticus.

Why we prefer levetiracetam over phenytoin for treatment of status epilepticus

Over last fifty years, intravenous (iv) phenytoin (PHT) loading dose has been the treatment of choice for patients with benzodiazepine-resistant convulsive status epilepticus and several guidelines recommended this treatment regimen with simultaneous iv diazepam. Clinical studies have never shown a better efficacy of PHT over other antiepileptic drugs. In addition, iv PHT loading dose is a complex and time-consuming procedure which may expose patients to several risks, such as local cutaneous reactions (purple glove syndrome), severe hypotension and cardiac arrhythmias up to ventricular fibrillation and death, and increased risk of severe allergic reactions. A further disadvantage of PHT is that it is a strong enzymatic inducer and it may make ineffective several drugs that need to be used simultaneously with antiepileptic treatment. In patients with a benzodiazepine-resistant status epilepticus, we suggest iv administration of levetiracetam as soon as possible. If levetiracetam would be ineffective, a further antiepileptic drug among those currently available for iv use (valproate, lacosamide, or phenytoin) can be added before starting third line treatment.

Updates in Refractory Status Epilepticus

Refractory status epilepticus is defined as persistent seizures despite appropriate use of two intravenous medications, one of which is a benzodiazepine. It can be seen in up to 40% of cases of status epilepticus with an acute symptomatic etiology as the most likely cause. New-onset refractory status epilepticus (NORSE) is a recently coined term for refractory status epilepticus where no apparent cause is found after initial testing. A large proportion of NORSE cases are eventually found to have an autoimmune etiology needing immunomodulatory treatment. Management of refractory status epilepticus involves treatment of an underlying etiology in addition to intravenous anesthetics and antiepileptic drugs. Alternative treatment options including diet therapies, electroconvulsive therapy, and surgical resection in case of a focal lesion should be considered. Short-term and long-term outcomes tend to be poor with significant morbidity and mortality with only one-third of patients reaching baseline neurological status.

[A nationwide multi-center questionnaire survey on the management and treatment of post-stroke seizure and epilepsy in Japan]

Seizures may occur after stroke. Though the majority of clinicians are aware of this, a consensus-based treatment and management strategy for post-stroke seizures is not available because there have only been a few large-scale studies that have explored this. This study has surveyed the actual state of medical treatment for post-stroke seizure and epilepsy in Japan. We conducted a nationwide questionnaire survey of the top 500 institutions regarding the number of cerebral infarction cases between February 2015 and May 2015. The questionnaire contained 14 items regarding the number of patients, type of tests and treatments conducted, and patient response to the treatments. Surveys from 189 institutions were obtained. A history of previous stroke was reported in 41% of hospitalized patients with epilepsy. The sensitivity of diffusion-weighted MRI and electroencephalography was not sufficient to detect the abnormalities seen in epilepsy. Carbamazepine was the most chosen antiepileptic drug for secondary prophylaxis, followed by valproate acid, and levetiracetam.

Status epilepticus: Role for etiology in determining response to benzodiazepines

OBJECTIVE

Clinical factors contributing to benzodiazepine failure in treating status epilepticus (SE) include suboptimal dosing and seizure duration. As many benzodiazepine-refractory episodes of SE arise from acute etiologies, we sought to determine whether etiology impacts SE treatment.

METHODS

The potency of diazepam to terminate SE induced by lithium-pilocarpine (LiPilo-SE) or kainic acid (KA-SE) in 3-week-old rats was studied by video-electroencephalography. Synaptic γ-aminobutyric acid type A receptor (GABAR)-mediated currents were recorded from dentate granule cells using voltage-clamp electrophysiology. Surface expression of γ2 subunit-containing GABARs and Kv4.2 potassium channels in hippocampal slices was determined using a biotinylation assay. Expression of phosphorylated forms of β2/3 and γ2 subunits was determined using phosphospecific antibodies and Western blotting.

RESULTS

Diazepam failed to terminate late SE in LiPilo-SE animals but was successful in terminating KA-SE of 1- and 3-hour duration. One hour after SE onset, GABAR-mediated synaptic inhibition and γ2 subunit-containing GABAR surface expression were reduced in LiPilo-SE animals. These were unchanged in KA-SE animals at 1 and 3 hours. Phosphorylation of γ2 subunit residue S327 was unchanged in both models, although GABAR β3 subunit S408/409 residues were dephosphorylated in the LiPilo-SE animals. Kv4.2 potassium channel surface expression was increased in LiPilo-SE animals but reduced in KA-SE animals.

INTERPRETATION

SE-model-dependent differences support a novel hypothesis that the development of benzodiazepine pharmacoresistance may be etiologically predetermined. Further studies are required to investigate the mechanisms that underlie such etiological differences during SE and whether etiology-dependent protocols for the treatment of SE need to be developed. Ann Neurol 2018;83:830-841.

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.

A critical appraisal of randomized controlled trials on intravenous phenytoin in convulsive status epilepticus

Since the 1970s, intravenous (IV) phenytoin (PHT) has traditionally been used as second-stage treatment for convulsive status epilepticus (SE) after failure of benzodiazepines. The aim of this review was to critically assess the evidence supporting the use of IV PHT as treatment of convulsive SE in patients of any age. In particular, we critically appraised the results of randomized controlled trials (RCTs) evaluating IV PHT as treatment of convulsive SE. A systematic search of the literature was carried out to identify RCTs evaluating IV PHT as treatment of convulsive SE in patients of any age. Eight RCTs (544 patients allocated to IV PHT) were included. The included studies differed in almost every single characteristic considered. Six RCTs (472 patients) used IV PHT without demonstrating refractoriness of SE to benzodiazepines. Only two RCTs (72 patients) used IV PHT as second-line treatment for benzodiazepine-resistant convulsive SE. Overall, most evidence from RCTs supports the use of IV PHT immediately after IV diazepam, even if seizures have not recurred. The recommendation derived from RCTs supporting the use of IV PHT as second-line treatment in benzodiazepine-resistant convulsive SE is weak. This is emblematic of the lack of robust evidence from large RCTs to inform clinical practice on how to treat SE after failure of first-line drugs. IV PHT given immediately after first-line benzodiazepines could prolong their short antiepileptic effect and prevent seizure recurrence.

Management of Status Epilepticus

Status epilepticus is due to a range of insults to the central nervous system and results in significant mortality rates, especially in the elderly. We review the current management of this disorder in light of the latest developments from recent trials and guidelines. Important principles in management includes early recognition of status epilepticus, identification of the underlying cause and prompt treatment to terminate seizures and reduce complications. The differentiation diagnosis, role of electroencephalographic monitoring and different treatment regimes are examined.

Electroencephalography and behavior patterns during experimental status epilepticus

OBJECTIVE

To characterize the evolution of behavioral and electrographic seizures in an experimental electrical stimulation-based model of status epilepticus (SE) in C57Bl/6 mice, and to relate SE to various outcomes, including death and epileptogenesis.

METHODS

SE was induced by continuous hippocampal stimulation and was evaluated by review of electroencephalographic recordings, spectral display, and behavior.

RESULTS

Seizures were initially locked to the electrical trains but later became independent of them. Following the end of stimulation, autonomous seizures continued for >5 minutes in 85% of the animals. There was ongoing 2-3-Hz rhythmic, high-amplitude, slow spike-wave discharges (HASDs) associated with purposeless, repetitive, continuously circling and exploratory behavior. There were high-amplitude fast discharges (HAFDs) associated with worsening of behavioral seizures that were interspersed with the ongoing HASDs. Death during SE occurred in 23% of the animals, and it was preceded by a stage 5 behavioral seizure. In the waning stage of SE, severe seizures and HAFDs dissipated, HASDs slowed down, and normal behavior was restored in most animals. Epilepsy developed in 33% of the animals monitored after SE.

SIGNIFICANCE

The electrical stimulation model of SE can be used to study mechanisms of SE and its adverse consequences, including death and epileptogenesis.

Evaluation of phenytoin serum levels following a loading dose in the acute hospital setting

PURPOSE

Due to the complex pharmacokinetic profiles of phenytoin (PHT) and fosphenytoin (FOS), achieving sustained, targeted serum PHT levels in the first day of use is challenging.

METHODS

A population based approach was used to analyze total serum PHT (tPHT) level within 2-24h of PHT/FOS loading with or without supplementary maintenance or additional loading doses among PHT-naïve patients in the acute hospital setting. Adequate tPHT serum level was defined as ≥20μg/mL.

RESULTS

Among 494 patients with 545 tPHT serum levels obtained in the first 2-24h after the loading dose (LD), tPHT serum levels of either

CONCLUSION

Close laboratory surveillance and PHT/FOS dose adjustments are recommended to ensure adequate and sustained tPHT serum levels early in treatment. Free serum PHT level is the preferred method of drug monitoring.

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Key Words

• Fosphenytoin
• Serum phenytoin level
• Status epilepticus

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MESH Headings

• Adolescent
• Adult
• Aged
• Aged, 80 and over
• Anticonvulsants/blood
• Anticonvulsants/therapeutic use
• Child
• Community Health Planning
• Epilepsy/blood
• Epilepsy/drug therapy
• Female
• Humans
• Male
• Middle Aged
• Phenytoin/blood
• Phenytoin/therapeutic use
• Retrospective Studies
• Statistics as Topic
• Young Adult

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Grants

• T32 ES007271 NIEHS NIH HHS
• TL1 TR002000 NCATS NIH HHS
• UL1 TR000042 NCATS NIH HHS
• UL1 TR002001 NCATS NIH HHS

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Affiliation(s)

Olga Selioutski Department of Neurology, Strong Epilepsy Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA.
Katherine Grzesik Department of Biostatistics, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
Olga N Vasilyeva Department of Pharmacy, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
Ágúst Hilmarsson Landspitali University Hospital, Slettuvegi, Reykjavik, Iceland
A James Fessler Department of Neurology, Strong Epilepsy Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
Lynn Liu Department of Neurology, Strong Epilepsy Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
Robert A Gross Department of Neurology, Strong Epilepsy Center, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA

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Comparison of lacosamide versus sodium valproate in status epilepticus: A pilot study

PURPOSE

The purpose of this study was to compare the efficacy and safety of lacosamide (LCM) and sodium valproate (SVA) in lorazepam (LOR)-resistant SE.

METHODS

Patients with LOR-resistant SE were randomized to intravenous LCM 400mg at the rate of 60mg/kg/min or SVA 30mg/kg at the rate of 100mg/min. The SE severity score (STESS), duration of SE and its etiology, and MRI findings were noted. Primary outcome was seizure cessation for 1h, and secondary outcomes were 24h seizure remission, in-hospital death, and severe adverse events (SAE).

RESULTS

Sixty-six patients were included, and their median age was 40 (range 18-90) years. Thirty-three patients each received LCM and SVA. Their demographic, clinical, STESS, etiology, and MRI findings were not significantly different. One-hour seizure remission was not significantly different between LCM and SVA groups (66.7% vs 69.7%; P=0.79). Twenty-four-hour seizure freedom was insignificantly higher in SVA (20, 66.6%) compared with LCM group (15, 45.5%). Death (10 vs 12) and composite side effects (4 vs 6) were also not significantly different in LCM and SVA groups. LCM was associated with hypotension and bradycardia (1 patient), and SVA with liver dysfunction (6).

CONCLUSION

In patients with LOR-resistant SE, both LCM and SVA have comparable efficacy and safety.