Mortality, Disability and Prognostic Factors of Status Epilepticus: A Nationwide Population-Based Retrospective Cohort Study

Burden of status epilepticus: prognosis and cost driving factors, insight from a nationwide retrospective cohort study of the French health insurance database

BACKGROUND

Status epilepticus (SE) imposes a significant burden in terms of in-hospital mortality and costs, but the relationship between SE causes, patient comorbidities, mortality, and cost remains insufficiently understood. We determined the in-hospital mortality and cost-driving factors of SE using a large and comprehensive database.

METHODS

We conducted a retrospective cohort study involving patients experiencing their first hospitalization with an ICD-10 code diagnosis of SE, spanning from January 1, 2015, to December 31, 2019, using the French health insurance database which covers 99% of population. Patient characteristics, SE causes, Intensive Care Unit (ICU) admissions, mechanical ventilation, discharge status, and health insurance costs were extracted for each hospitalization.

RESULTS

We identified 52,487 patients hospitalized for a first SE. In-hospital mortality occurred in 11,464 patients (21.8%), with associated factors including age (Odds Ratio [OR], 10.3, 95% Confidence Interval [CI] 7.87-13.8 for ages over 80 compared to 10-19), acute causes (OR, 15.3, 95% CI 13.9-16.8 for hypoxic cause), tumors (OR, 1.75, 95% CI 1.63-1.8), comorbidities (OR, 3.00, 95% CI 2.79-3.24 for 3 or more comorbidities compared to 0), and prolonged mechanical ventilation (OR, 2.61, 95% CI 2.42-2.82). The median reimbursed cost for each SE hospitalization was 6517€ (3364-13,354), with cost factors mirroring those of in-hospital mortality.

CONCLUSION

Causes and co-morbidities are major determinants of mortality and hospital costs in status epilepticus, and factors associated with higher mortality are also often associated with higher costs. Further studies are needed to identify their long-term effects.

Mortality and morbidity of status epilepticus over the long term

Status epilepticus is associated with high mortality and morbidity, both in the acute phase and over the long term. However, the long-term outcome of SE is not well studied, and there is no consensus on how to measure and predict it. Moreover, the factors that influence the long-term outcome of SE are complex and multifactorial, and may vary depending on the patient's characteristics, the SE etiology and type, and the treatment and complications. The aim of this article is to review the current literature on the mortality and morbidity of SE over the long term and to discuss the challenges and perspectives for future research. Proceedings of the 9th London-Innsbruck Colloquium on Status Epilepticus and acute seizures.

Levetiracetam or Phenytoin as Prophylaxis for Status Epilepticus: Secondary Analysis of the "Approaches and Decisions in Acute Pediatric Traumatic Brain Injury Trial" (ADAPT) Dataset, 2014-2017

OBJECTIVES

To compare levetiracetam and phenytoin as prophylaxis for the short-term development of status epilepticus (SE) during care of pediatric patients with acute severe traumatic brain injury (TBI).

DESIGN

Nonprespecified secondary analysis using propensity score matching.

SETTING

We used the Approaches and Decisions in Acute Pediatric TBI Trial (ADAPT NCT04077411) dataset (2014-2017).

SUBJECTS

Patients less than 18 years old with Glasgow Coma Scale Score less than or equal to 8 who received levetiracetam or phenytoin as a prophylactic anticonvulsant therapy.

INTERVENTION

None.

MEASUREMENT AND MAIN RESULTS

Of the 516 total patients who qualified for the case-control study, 372 (72.1%) patients received levetiracetam, and 144 (27.9%) received phenytoin. After propensity score matching, the pair-matched analysis with 133 in each group failed to identify an association between levetiracetam versus phenytoin use and occurrent of SE (3.8% vs. 0.8%, p = 0.22), or mortality (i.e., in-hospital, 30-d and 60-d). However, on closer inspection of the statistical testing, we cannot exclude the possibility that selecting levetiracetam rather than phenytoin for prophylaxis was associated with the following: up to a mean difference of 7.3% greater prevalence of SE; up to a mean difference of 13.9%, 12.1%, and 13.9% greater mortality during the hospital stay, and 30-, and 60-days after hospital arrival, respectively. Last, analysis of 6 months Glasgow Outcome Scale Extended score in those without premorbid comorbidities, there was an association between favorable outcomes and use of phenytoin rather than levetiracetam prophylaxis.

CONCLUSIONS

In ADAPT, the decision to use prophylactic levetiracetam versus phenytoin failed to show an association with occurrence of subsequent SE, or mortality. However, we are unable to exclude the possibility that selecting levetiracetam rather than phenytoin for prophylaxis was associated with greater prevalence of SE and mortality. We are unable to make any recommendation about one prophylactic anticonvulsant medication over the other, but recommend that further larger, contemporary studies in severe pediatric TBI are carried out.

Relative Bioavailability Study of Midazolam Intramuscularly Administered with the Needle-Free Auto-Injector ZENEO® in Healthy Adults

INTRODUCTION

Intramuscular (IM) midazolam is indicated for the treatment of status epilepticus. Administration must be efficient to rapidly terminate prolonged seizures and prevent complications. The objective of this study was to compare, in terms of relative bioavailability and bioequivalence, IM midazolam injection by needle-free auto-injector, in different settings, to IM midazolam injection by a conventional syringe and needle.

METHODS

In this open-label, randomized, four-period crossover study, healthy adults received single doses of midazolam (10 mg) under fasting conditions. The reference treatment (conventional syringe) was administered once, on bare skin in the thigh. The tested treatment (the needle-free auto-injector ZENEO®) was administered three times: on bare skin in the thigh, on bare skin in the ventrogluteal area, and through clothing in the thigh. Repeated plasma samples were collected to obtain 36-h pharmacokinetic (PK) profiles. Primary PK parameters were area under the plasma concentration-time curve, from time zero to the last measurable time point (AUC0-t) and from time zero to infinity (AUC0-∞), and the maximum observed plasma concentration (Cmax).

RESULTS

Forty adults were enrolled and included in the PK analysis set. In all comparisons, the 90% confidence interval (CI) of the least-squares geometric mean ratios for AUC0-t and AUC0-∞ were within the bioequivalence range of 80-125%, with low intra-individual coefficients of variation (< 20.5% for all parameters in all comparisons). Bioequivalence was also met for Cmax in all comparisons except when comparing the tested treatment through clothing versus the reference treatment, where the 90% CI lower limit was slightly outside the bioequivalence range (78.8%). With all tested treatments Cmax was slightly lower, but early mean plasma concentrations (first 10 min post-dosing) were higher when compared to the reference treatment. In general, all treatments were well tolerated, with maximum sedation 0.5-1 h post-injection.

DISCUSSION/CONCLUSION

This study establishes that IM midazolam injection on bare skin in the thigh with the ZENEO® is bioequivalent to IM midazolam injection with a syringe and needle. An acceptable relative bioavailability, compatible with emergency practice, was also shown in multiple settings. Higher mean concentrations within the first 10 min with the ZENEO® device, and quicker two-step injection suggest a faster onset of action, and thereby an earlier seizure termination, thus preventing the occurrence of prolonged seizure and neurological complications.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov identifier: NCT05026567. Registration first posted August 30, 2021, first patient enrolled May 9, 2022.

Pre-treatment risk predictors of valproic acid-induced dyslipidemia in pediatric patients with epilepsy

Background: Valproic acid (VPA) stands as one of the most frequently prescribed medications in children with newly diagnosed epilepsy. Despite its infrequent adverse effects within therapeutic range, prolonged VPA usage may result in metabolic disturbances including insulin resistance and dyslipidemia. These metabolic dysregulations in childhood are notably linked to heightened cardiovascular risk in adulthood. Therefore, identification and effective management of dyslipidemia in children hold paramount significance. Methods: In this retrospective cohort study, we explored the potential associations between physiological factors, medication situation, biochemical parameters before the first dose of VPA (baseline) and VPA-induced dyslipidemia (VID) in pediatric patients. Binary logistic regression was utilized to construct a predictive model for blood lipid disorders, aiming to identify independent pre-treatment risk factors. Additionally, The Receiver Operating Characteristic (ROC) curve was used to evaluate the performance of the model. Results: Through binary logistic regression analysis, we identified for the first time that direct bilirubin (DBIL) (odds ratios (OR) = 0.511, p = 0.01), duration of medication (OR = 0.357, p = 0.009), serum albumin (ALB) (OR = 0.913, p = 0.043), BMI (OR = 1.140, p = 0.045), and aspartate aminotransferase (AST) (OR = 1.038, p = 0.026) at baseline were independent risk factors for VID in pediatric patients with epilepsy. Notably, the predictive ability of DBIL (AUC = 0.690, p < 0.0001) surpassed that of other individual factors. Furthermore, when combined into a predictive model, incorporating all five risk factors, the predictive capacity significantly increased (AUC = 0.777, p < 0.0001), enabling the forecast of 77.7% of dyslipidemia events. Conclusion: DBIL emerges as the most potent predictor, and in conjunction with the other four factors, can effectively forecast VID in pediatric patients with epilepsy. This insight can guide the formulation of individualized strategies for the clinical administration of VPA in children.

Ketamine Efficacy for Management of Status Epilepticus: Considerations for Prehospital Clinicians

Current first-line therapies for seizure management recommend benzodiazepines, which target gamma-aminobutyric acid type A channels to stop the seizure activity. However, seizures may be refractory to traditional first-line therapies, transitioning into status epilepticus and becoming resistant to gamma-aminobutyric acid type A augmenting drugs. Although there are other antiseizure medications available for clinicians to use in the intensive care unit, these options can be less readily available outside of the intensive care unit and entirely absent in the prehospital setting. Instead, patients frequently receive multiple doses of first-line agents with increased risk of hemodynamic or airway collapse. Ketamine is readily available in the prehospital setting and emergency department, has well-established antiseizure effects with a favorable safety profile, and is a drug often used for several other indications. This article aimed to explore the utilization of ketamine for seizure management in the prehospital setting, reviewing seizure pathophysiology, established treatment mechanisms of action and pharmacokinetics, and potential benefits of early ketamine use in status epilepticus.

Analysis of factors influencing the efficacy of vagus nerve stimulation for the treatment of drug-resistant epilepsy in children and prediction model for efficacy evaluation

Objective

Vagus nerve stimulation (VNS) has been widely used in the treatment of drug-resistant epilepsy (DRE) in children. We aimed to explore the efficacy and safety of VNS, focusing on factors that can influence the efficacy of VNS, and construct a prediction model for the efficacy of VNS in the treatment of DRE children.

Methods

Retrospectively analyzed 45 DRE children who underwent VNS at Qilu Hospital of Shandong University from June 2016 to November 2022. A ≥50% reduction in seizure frequency was defined as responder, logistic regression analyses were performed to analyze factors affecting the efficacy of VNS, and a predictive model was constructed. The predictive model was evaluated by receiver operating characteristic curve (ROC), calibration curves, and decision curve analyses (DCA).

Results

A total of 45 DRE children were included in this study, and the frequency of seizures was significantly reduced after VNS treatment, with 25 responders (55.6%), of whom 6 (13.3%) achieved seizure freedom. There was a significant improvement in the Quality of Life in Childhood Epilepsy Questionnaire (15.5%) and Seizure Severity Score (46.2%). 16 potential factors affecting the efficacy of VNS were included, and three statistically significant positive predictors were ultimately screened: shorter seizure duration, focal seizure, and absence of intellectual disability. We developed a nomogram for predicting the efficacy of VNS in the treatment of DRE children. The ROC curve confirmed that the predictive model has good diagnostic performance (AUC = 0.864, P < 0.05), and the nomogram can be further validated by bootstrapping for 1,000 repetitions, with a C-index of 0.837. Besides, this model showed good fitting and calibration and positive net benefits in decision curve analysis.

Conclusion

VNS is a safe and effective treatment for DRE children. We developed a predictive nomogram for the efficacy of VNS, which provides a basis for more accurate selection of VNS patients.

Status epilepticus in the ICU

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

Acute Symptomatic Seizures After Ischemic Strokes: Time Is Brain, Squared!

Association of Mortality and Risk of Epilepsy With Type of Acute Symptomatic Seizure After Ischemic Stroke and an Updated Prognostic Model Sinka L, Abraira L, Imbach LL, Zieglgänsberger D, Santamarina E, Álvarez-Sabín J, Ferreira-Atuesta C, Katan M, Scherrer N, Bicciato G, Terziev R, Simmen C, Schubert KM, Elshahabi A, Baumann CR, Döhler N, Erdélyi-Canavese B, Felbecker A, Siebel P, Winklehner M, von Oertzen TJ, Wagner JN, Gigli GL, Serafini A, Nilo A, Janes F, Merlino G, Valente M, Zafra-Sierra MP, Bayona-Ortiz H, Conrad J, Evers S, Lochner P, Roell F, Brigo F, Bentes C, Peralta AR, Pinho E Melo T, Keezer MR, Duncan JS, Sander JW, Tettenborn B, Koepp MJ, Galovic M. JAMA Neurol . 2023;80(6):605-613. doi:10.1001/jamaneurol.2023.0611 . PMID: 37036702 ; PMCID: PMC10087089 Importance: Acute symptomatic seizures occurring within 7 days after ischemic stroke may be associated with an increased mortality and risk of epilepsy. It is unknown whether the type of acute symptomatic seizure influences this risk. Objective: To compare mortality and risk of epilepsy following different types of acute symptomatic seizures. Design, Setting, and Participants: This cohort study analyzed data acquired from 2002 to 2019 from 9 tertiary referral centers. The derivation cohort included adults from 7 cohorts and 2 case-control studies with neuroimaging-confirmed ischemic stroke and without a history of seizures. Replication in 3 separate cohorts included adults with acute symptomatic status epilepticus after neuroimaging-confirmed ischemic stroke. The final data analysis was performed in July 2022. Exposures: Type of acute symptomatic seizure. Main Outcomes and Measures: All-cause mortality and epilepsy (at least 1 unprovoked seizure presenting >7 days after stroke). Results: A total of 4552 adults were included in the derivation cohort (2547 male participants [56%]; 2005 female [44%]; median age, 73 years [IQR, 62-81]). Acute symptomatic seizures occurred in 226 individuals (5%), of whom 8 (0.2%) presented with status epilepticus. In patients with acute symptomatic status epilepticus, 10-year mortality was 79% compared with 30% in those with short acute symptomatic seizures and 11% in those without seizures. The 10-year risk of epilepsy in stroke survivors with acute symptomatic status epilepticus was 81%, compared with 40% in survivors with short acute symptomatic seizures and 13% in survivors without seizures. In a replication cohort of 39 individuals with acute symptomatic status epilepticus after ischemic stroke (24 female; median age, 78 years), the 10-year risk of mortality and epilepsy was 76% and 88%, respectively. We updated a previously described prognostic model (SeLECT 2.0) with the type of acute symptomatic seizures as a covariate. SeLECT 2.0 successfully captured cases at high risk of poststroke epilepsy. Conclusions and relevance: In this study, individuals with stroke and acute symptomatic seizures presenting as status epilepticus had a higher mortality and risk of epilepsy compared with those with short acute symptomatic seizures or no seizures. The SeLECT 2.0 prognostic model adequately reflected the risk of epilepsy in high-risk cases and may inform decisions on the continuation of anti-seizure medication treatment and the methods and frequency of follow-up.

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

OBJECTIVE

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

METHODS

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

RESULTS

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

CONCLUSION

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

Clonazepam Loading Dose in Status Epilepticus: Is More Always Better?

BACKGROUND AND OBJECTIVES

Benzodiazepines are the first treatment line in status epilepticus (SE). Despite their well-established benefit, benzodiazepines are frequently underdosed with potential detrimental consequences. In some European countries, clonazepam (CLZ) is commonly used as the first line treatment. The aim of this study was to explore the correlation between CLZ loading doses and SE outcome.

METHODS

This study included a retrospective analysis of a prospective registry in Lausanne, Switzerland (CHUV Lausanne University Hospital), including all SE episodes treated between February 2016 and February 2021. Only adults (> 16 years old) were included with CLZ used as the first treatment line. Post-anoxic SE were excluded because of significant differences in physiopathology and prognosis. Patient characteristics, SE features, the validated SE severity score (STESS), and treatment characteristics were prospectively recorded. We considered loading doses of 0.015 mg/kg or higher (following commonly recommended loading doses) as high doses. We analyzed outcome in terms of number of treatment lines after the CLZ, proportion of refractory episodes, intubation for airways protection, intubation for SE treatment, and mortality. We performed univariable analyses to investigate the association between loading doses and clinical response. A multivariable stepwise backward binary logistic regression was applied for adjusting for potential confounders. Multivariable linear regression was similarly used to analyze CLZ dose as a continuous variable.

RESULTS

We collected 251 SE episodes in 225 adult patients. Median CLZ loading dose was 0.010 mg/kg. CLZ high doses were used in 21.9% of SE episodes (in 43.8% for > 80% of the high dose). Thirteen percent of patients with SE were intubated for airways control, while intubation was needed in 12.7% for SE treatment. High CLZ loading doses were independently associated with younger age (median 62 versus 68 years old, p = 0.002), lesser weight (65 kg versus 75 kg, p = 0.001) and more frequent intubation for airways protection (23% vs 11%, p = 0.013), but differing CLZ dose was not associated with any outcome parameter.

CONCLUSION

CLZ high doses were more frequently used for SE treatment in younger patients with healthy weight and were more often associated with intubation for airways protection, probably as an adverse event. Varying CLZ dose did not alter outcome in SE, raising the possibility that commonly recommended doses are above what is needed, at least in some patients. Our results suggest that CLZ doses in SE may be individualized depending on the clinical setting.

Management of convulsive status epilepticus: recent updates

Convulsive status epilepticus (SE) is a medical emergency associated with high morbidity and mortality. Recently, clinical trials and meta-analyses investigating medical treatment of SE have been published. Benzodiazepine is well known as the first-line treatment for SE. Recent evidence suggests the equivalence of intravenous fosphenytoin, valproate, and levetiracetam for treatment of established SE. There is lack of evidence regarding treatment for refractory SE. Intravenous midazolam is commonly used, and recent evidence supports the use of ketamine. Additional studies are needed to improve the management of convulsive SE.

Specific profiles of new-onset vs. non-inaugural status epilepticus: From diagnosis to 1-year outcome

While new-onset status epilepticus (NOSE) is a harbinger of chronic epilepsy, prospective medical data are sparse in terms of specifying whether the evolution of status epilepticus (SE) and seizure expression in NOSE resembles what occurs in patients who have already been diagnosed with epilepsy [non-inaugural SE (NISE)] in all aspects apart from its inaugural nature. The aim of this study was to compare the clinical, MRI, and EEG features that could distinguish NOSE from NISE. We conducted a prospective monocentric study in which all patients ≥18 years admitted for SE over a 6-month period were included. A total of 109 patients (63 NISE and 46 NOSE cases) were included. Despite similar modified Rankin scores before SE, several aspects of the clinical history distinguished NOSE from NISE patients. NOSE patients were older and frequently had neurological comorbidity and preexisting cognitive decline, but they had a similar prevalence of alcohol consumption to NISE patients. NOSE and NISE evolve in the same proportions as refractory SE (62.5% NOSE, 61% NISE) and share common features such as the same incidence (33% NOSE, 42% NISE, and p = 0.53) and volumes of peri-ictal abnormalities on MRI. However, in NOSE patients, we observed greater non-convulsive semiology (21.7% NOSE, 6% NISE, and p = 0.02), more periodic lateral discharges on EEG (p = 0.004), later diagnosis, and higher severity according to the STESS and EMSE scales (p < 0.0001). Mortality occurred in 32.6% of NOSE patients and 21% of NISE patients at 1 year (p = 0.19), but with different causes of death occurring at different time points: more early deaths directly linked to SE at 1 month occurred in the NOSE group, while there were more remote deaths linked to causal brain lesions in the NISE group at final follow-up. In survivors, 43.6% of the NOSE cases developed into epilepsy. Despite acute causal brain lesions, the novelty related to its inaugural nature is still too often associated with a delay in diagnosing SE and a poorer outcome, which justifies the need to more clearly specify the various types of SE to constantly raise awareness among clinicians. These results highlight the relevance of including novelty-related criteria, clinical history, and temporality of occurrence in the nosology of SE.