Epidemiology-Based Mortality Score is Associated with Long-Term Mortality after Status Epilepticus

Two-year mortality and seizure recurrence following status epilepticus in Auckland, New Zealand: A prospective cohort study

PURPOSE

To document the 2-year mortality and seizure recurrence rate of a prospective cohort of patients identified with status epilepticus (SE).

METHODS

Patients presenting to any hospital in the Auckland region between April 6 2015, and April 5 2016, with a seizure lasting 10 min or longer were identified. Follow up was at 2 years post index SE episode via telephone calls and detailed review of clinical notes.

RESULTS

We identified 367 patients with SE over the course of one year. 335/367 (91.3 %) were successfully followed up at the 2-year mark. Two-year all-cause mortality was 50/335 (14.9 %), and 49/267 (18.4 %) when febrile SE was excluded. Two-year seizure recurrence was 197/335 (58.8 %). On univariate analyses, children (preschoolers 2 to < 5 years and children 5 to < 15 years), Asian ethnicity, SE duration <30 mins and acute (febrile) aetiology were associated with lower mortality, while older age >60 and progressive causes were associated with higher mortality on both univariate and multivariate analyses. Age < 2 years and acute aetiology were associated with lower seizure recurrence, while non convulsive status epilepticus (NCSE) with coma and a history of epilepsy were associated with higher seizure recurrence. On multivariate analyses, a history of epilepsy, as well as having both acute and remote causes were associated with higher seizure recurrence.

CONCLUSIONS

All-cause mortality in both the paediatric and adult populations at 2 years was lower than most previous reports. Older age, SE duration ≥30 mins and progressive aetiologies were associated with the highest 2-year mortality, while febrile SE had the lowest mortality. A history of epilepsy, NCSE with coma, and having both acute and remote causes were associated with higher seizure recurrence at 2 years. Future studies should focus on functional measures of outcome and long-term quality of life.

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.

Nonconvulsive status epilepticus in neurocritical care: A critical reappraisal of outcome prediction scores

OBJECTIVE

Nonconvulsive status epilepticus (NCSE) is a frequent condition in the neurocritical care unit (NCCU) patient population, with high morbidity and mortality. We aimed to assess the validity of available outcome prediction scores for prognostication in an NCCU patient population in relation to their admission reason (NCSE vs. non-NCSE related).

METHODS

All 196 consecutive patients diagnosed with NCSE during the NCCU stay between January 2010 and December 2020 were included. Demographics, Simplified Acute Physiology Score II (SAPS II), NCSE characteristics, and in-hospital and 3-month outcome were extracted from the electronic charts. Status Epilepticus Severity Score (STESS), Epidemiology-Based Mortality Score in Status Epilepticus (EMSE), and encephalitis, NCSE, diazepam resistance, imaging features, and tracheal intubation score (END-IT) were evaluated as previously described. Univariable and multivariable analysis and comparison of sensitivity/specificity/positive and negative predictive values/accuracy were performed.

RESULTS

A total of 30.1% died during the hospital stay, and 63.5% of survivors did not achieve favorable outcome at 3 months after onset of NCSE. Patients admitted primarily due to NCSE had longer NCSE duration and were more likely to be intubated at diagnosis. The receiver operating characteristic (ROC) for SAPS II, EMSE, and STESS when predicting mortality was between .683 and .762. The ROC for SAPS II, EMSE, STESS, and END-IT when predicting 3-month outcome was between .649 and .710. The accuracy in predicting mortality/outcome was low, when considering both proposed cutoffs and optimized cutoffs (estimated using the Youden Index) as well as when adjusting for admission reason.

SIGNIFICANCE

The scores EMSE, STESS, and END-IT perform poorly when predicting outcome of patients with NCSE in an NCCU environment. They should be interpreted cautiously and only in conjunction with other clinical data in this particular patient group.

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

BACKGROUND AND OBJECTIVES

The outcome of status epilepticus (SE) largely varies depending on clinical characteristics. Risk stratification is necessary for tailoring the aggressiveness of treatment and predicting outcomes of individual patients with SE. In this study, we assessed differences in mortality, neurologic disability, and prognostic factors associated with SE across sociodemographic and clinical characteristics.

METHODS

We conducted a nationwide population-based retrospective cohort study using the National Health Insurance Service (NHIS) database linked with the national death and disability registries. SE was identified from admission or emergency room visits using a diagnostic code of G41 from the International Classification of Disease, 10^th Revision. Individuals with new-onset SE that occurred from January 1, 2010, to December 31, 2018, were included. Active epilepsy, refractoriness of SE, potential etiology, and comorbidities were ascertained by diagnostic codes and/or prescription records from the NHIS database as potential prognostic factors. Outcomes included 30-day and 1-year mortality and neurologic disabilities following SE. Prognostic factors for mortality were assessed by the Cox regression hazard model. We performed a subgroup analysis according to age: pediatric SE (age < 20 years old) and adult SE (age ≥ 20 years old).

RESULTS

A total of 33,814 new-onset SE patients were included (6,818 children/adolescents and 26,996 adults). The 30-day mortality was 8.5% (1.8% in pediatric SE and 10.2% in adult SE), and the 1-year mortality was 25.1% (4.6% in pediatric SE and 30.3% in adult SE). Overall, 10.7% of patients newly acquired neurologic disabilities following SE, with the highest incidence in children aged 5 to 9 years (21.3%). Intractable epilepsy developed in 0.8% of entire SE. Old age, presence of acute etiology, and refractoriness were poor prognostic factors for mortality in both pediatric and adult SE. Male sex, low economic status, no active epilepsy, and comorbidities were additional factors for a poor prognosis in adults.

CONCLUSIONS

New-onset SE was associated with substantial mortality and disability. While SE-related mortality was higher in adults, disabilities developed more commonly in children and adolescents. The major determinants of mortality differed between pediatric and adult SE.

Prediction of Long-term Survival After Status Epilepticus Using the ACD Score

Importance

Early prediction of long-term mortality in status epilepticus is important given the high fatality rate in the years after diagnosis.

Objective

To improve prognostication of long-term mortality after status epilepticus diagnosis.

Design, Settings, and Participants

This retrospective, multicenter, multinational cohort study analyzed adult patients who were diagnosed with and treated for status epilepticus at university hospitals in Odense, Denmark, between January 1, 2008, and December 31, 2017, as well as in Oslo, Norway; Marburg, Germany; and Frankfurt, Germany. They were aged 18 years or older and had first-time, nonanoxic status epilepticus. A new scoring system, called the ACD score, for predicting 2-year (long-term) mortality after hospital discharge for status epilepticus was developed in the Danish cohort and validated in the German and Norwegian cohorts. The ACD score represents age at onset, level of consciousness at admission, and duration of status epilepticus. Data analysis was performed between September 1, 2019, and March 31, 2020.

Exposures

Long-term follow-up using data from national and local civil registries in Denmark, Norway, and Germany.

Main Outcomes and Measures

The predefined end point was 2-year survival for all patients and for a subgroup of patients with status epilepticus causes that were not damaging or were less damaging to the brain. Neurological deficits before and after onset, demographic characteristics, etiological categories of status epilepticus, comorbidities, survival, time points, treatments, and prognostic scores for different measures were assessed.

Results

A total of 261 patients (mean [SD] age, 67.2 [14.8] years; 132 women [50.6%]) were included, of whom 145 patients (mean [SD] age, 66.3 [15.0] years; 78 women [53.8%]) had status epilepticus causes that were not damaging or were less damaging to the brain. The validation cohort comprised patients from Norway (n = 139) and Germany (n = 906). At hospital discharge, 29.8% of patients (n = 64 of 215) had new moderate to severe neurological deficits compared with baseline. New neurological deficits were a major predictor of 2-year survival after hospital discharge (odds ratio, 5.1; 95% CI, 2.2-11.8); this association was independent of etiological category. Nonconvulsive status epilepticus in coma and duration of status epilepticus were associated with development of new neurological deficits, and a simple 3-factor score (ACD score) combining these 2 risk factors with age at onset was developed to estimate survival after status epilepticus diagnosis. The ACD score had a linear correlation with 2-year survival (Pearson r2 = 0.848), especially in the subset of patients with a low likelihood of brain damage.

Conclusions and Relevance

This study found that age, long duration, and nonconvulsive type of status epilepticus in coma were associated with the development of new neurological deficits, which were predictors of long-term mortality. Accounting for risk factors for new neurological deficits using the ACD score is a reliable method of prediction of long-term outcome in patients with status epilepticus causes that were not damaging or were less damaging to the brain.

An Insight into Molecular Mechanisms and Novel Therapeutic Approaches in Epileptogenesis

Epilepsy is the second most common neurological disease with abnormal neural activity involving the activation of various intracellular signalling transduction mechanisms. The molecular and system biology mechanisms responsible for epileptogenesis are not well defined or understood. Neuroinflammation, neurodegeneration and Epigenetic modification elicit epileptogenesis. The excessive neuronal activities in the brain are associated with neurochemical changes underlying the deleterious consequences of excitotoxicity. The prolonged repetitive excessive neuronal activities extended to brain tissue injury by the activation of microglia regulating abnormal neuroglia remodelling and monocyte infiltration in response to brain lesions inducing axonal sprouting contributing to neurodegeneration. The alteration of various downstream transduction pathways resulted in intracellular stress responses associating endoplasmic reticulum, mitochondrial and lysosomal dysfunction, activation of nucleases, proteases mediated neuronal death. The recently novel pharmacological agents modulate various receptors like mTOR, COX-2, TRK, JAK-STAT, epigenetic modulators and neurosteroids are used for attenuation of epileptogenesis. Whereas the various molecular changes like the mutation of the cell surface, nuclear receptor and ion channels focusing on repetitive episodic seizures have been explored by preclinical and clinical studies. Despite effective pharmacotherapy for epilepsy, the inadequate understanding of precise mechanisms, drug resistance and therapeutic failure are the current fundamental problems in epilepsy. Therefore, the novel pharmacological approaches evaluated for efficacy on experimental models of epilepsy need to be identified and validated. In addition, we need to understand the downstream signalling pathways of new targets for the treatment of epilepsy. This review emphasizes on the current state of novel molecular targets as therapeutic approaches and future directions for the management of epileptogenesis. Novel pharmacological approaches and clinical exploration are essential to make new frontiers in curing epilepsy.

Predictors of mortality at one year after generalized convulsive status epilepticus

BACKGROUND

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

MATERIALS AND METHODS

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

RESULTS

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

CONCLUSIONS

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