Predictors of hospital and one-year mortality in intensive care patients with refractory status epilepticus: a population-based study

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.

Postictal Encephalopathy After Status Epilepticus: Outcome and Risk Factors

BACKGROUND

Postictal encephalopathy is well known after status epilepticus (SE), but its prognostic impact and triggers are unknown. Here, we aimed to establish risk factors for the development of postictal encephalopathy and to study its impact on survival after discharge.

METHODS

This retrospective cohort study comprised adult patients diagnosed with first nonanoxic SE at Odense University Hospital between January 2008 and December 2017. Patients with ongoing SE at discharge or unknown treatment success were excluded. Postictal symptoms of encephalopathy were estimated retrospectively using the West Haven Criteria (WHC). WHC grade was determined for postictal day 1 to 14 or until the patient died or was discharged from the hospital. Cumulative postictal WHC during 14 days after SE-cessation was used to quantify postictal encephalopathy. Clinical characteristics, patient demographics, electroencephalographic and imaging features, and details on intensive care treatment were assessed from medical records.

RESULTS

Of all eligible patients (n = 232), 198 (85.3%) had at least WHC grade 2 postictal encephalopathy that lasted for > 14 days in 24.5% of the surviving patients. WHC grade at discharge was strongly associated with poor long-term survival (p < 0.001). Postictal encephalopathy was not associated with nonconvulsive SE, postictal changes on magnetic resonance imaging, or distinct ictal patterns on electroencephalography. Although duration of SE and treatment in the intensive care unit showed an association with cumulative postictal WHC grade, they were not independently associated with the degree of encephalopathy when controlling for confounders. In a linear regression model, etiology, duration of sedation, age, and premorbid modified Rankin Scale were significant and consistent predictors for higher cumulative postictal WHC grade. Exploratory analyses showed an association of a cumulative midazolam dosage (mg/kg/h) with higher cumulative postictal WHC grade.

DISCUSSION

In this cohort, postictal encephalopathy after SE was common and associated with poor long-term survival. Seizure characteristics were not independently associated with postictal encephalopathy; the underlying etiology, long (high-dose midazolam) sedation, high age, and poor premorbid condition were the major risk factors for its development.

Outcomes and Treatment Approaches for Super-Refractory Status Epilepticus: A Systematic Review and Meta-Analysis

Importance

Super-refractory status epilepticus (SRSE) is defined as status epilepticus (SE) that continues or recurs 24 hours or more after the onset of anesthetic therapy or recurs on the reduction/withdrawal of anesthesia. Current clinical knowledge of the disease and optimal treatment approach is sparse.

Objective

To systematically assess clinical characteristics, causes, outcomes, prognostic factors, and treatment approaches for patients with SRSE.

Design, Setting, and Participants

In this systematic review and meta-analysis, all studies reporting adult patients (18 years or older) diagnosed with nonanoxic SRSE were considered for inclusion, irrespective of study design. The databases used were MEDLINE, Cochrane Library, EMBASE, and ClinicalTrials.org (database inception through May 5, 2022).

Data extraction and synthesis

The study complied with the PRISMA guidelines for reporting, data extraction, and data synthesis. Different tools were used to assess risk of bias. All available data were extracted and missing data were neither imputed nor completed by contacting the study authors.

Main outcome and measures

Successful treatment of SRSE, in-hospital mortality, and disability at discharge (estimated modified Rankin Scale).

Results

The study team identified a total of 95 articles and 30 conference abstracts reporting 1200 patients with nonanoxic SRSE (266 individual patients were available for meta-analysis). They had a mean SRSE duration of 36.3 days, mean age of 40.8 years, and equal sex distribution. Patients with SRSE had a distinct pattern of etiologies where acute cerebral events and unknown etiologies accounted for 41.6% and 22.3% of all etiologies, respectively. Reports of SRSE caused by, eg, alcohol, drugs, or tumors were rare. At discharge, only 26.8% had none to slight disability (none, 16 [8.4%]; nonsignificant and slight disability, 35 [18.4%]). In-hospital mortality was 24.1%. Mortality stabilized after long-term treatment (more than 28 days) but with increased rates of seizure cessation and moderate to severe disability. Established prognostic factors, such as age and etiology, were not associated with in-hospital mortality. Reported treatment with ketamine, phenobarbital, other barbiturates, vagus nerve stimulator, and ketogenic diet were not associated with outcome.

Conclusion and Relevance

Patients with SRSE are distinct due to their pattern of care (eg, long-term treatment to younger patients without negative prognostic factors and unknown/nonmalignant etiologies) and their natural course of SE. Very long-term treatment was associated with lower mortality and high odds of cessation of SRSE but increased risk of moderate to severe disability.

Long-term outcomes in refractory status epilepticus

INTRODUCTION

Refractory status epilepticus (RSE) is a diagnosis that can be made when tonic-clonic status epilepticus (SE) and focal SE cannot be stopped by at least two anti-seizure medications after 30 and 60 minutes, respectively, from the time of commencement. It could result in mortality, loss of functionality, neurological deficiency, and other serious short- and long-term effects.

AREAS COVERED

This narrative review covers original clinical studies of any design and case series investigating long-term outcomes of RSE recorded after at least a year from the SE onset.

EXPERT OPINION

The future of a patient with RSE rests mostly on the long-term effects of this severe pathological condition, which may be accompanied with systemic complications like hyperthermia, hyperkalemia, acidosis, and/or stress cardiomyopathy. Younger patients with less severe RSE of shorter duration, particularly of the convulsive kind, are reported to have better long-term outcomes. Previous studies on the factors influencing the long-term outcomes of RSE, however, did not link the outcomes to treatment options for the condition. Such circumstances currently prevent making any definitive recommendations on the treatment of RSE until future research with adequate statistical power is completed.

Management and outcomes of critically ill adult patients with convulsive status epilepticus and preadmission functional impairments

OBJECTIVE

Functional status is among the criteria relevant to decisions about intensive care unit (ICU) admission and level of care. Our main objective was to describe the characteristics and outcomes of adult patients requiring ICU admission for Convulsive Status Epilepticus (CSE) according to whether their functional status was previously impaired.

METHODS

We retrospectively analyzed data from consecutive adults who were admitted to two French ICUs for CSE between 2005 and 2018 and then included them retrospectively in the Ictal Registry. Pre-existing functional impairment was defined as a Glasgow Outcome Scale (GOS) score of 3 before admission. The primary outcome measure was a loss of ≥1 GOS score point at 1 year. Multivariate analysis was used to identify factors associated with this measure.

RESULTS

The 206 women and 293 men had a median age of 59 years [47-70 years]. The preadmission GOS score was 3 in 56 (11.2%) patients and 4 or 5 in 443 patients. Compared to the GOS-4/5 group, the GOS-3 group was characterized by a higher frequency of treatment-limitation decisions (35.7% vs. 12%, P < 0.0001), similar ICU mortality (19.6 vs. 13.1, P = 0.22), higher 1-year mortality (39.3% vs. 25.6%, P < 0.01), and a similar proportion of patients with no worsening of the GOS score at 1 year (42.9 vs. 44.1, P = 0.89). By multivariate analysis, not achieving a favorable 1-year outcome was associated with age above 59 years (OR, 2.36; 95%CI, 1.55-3.58, P < 0.0001), preexisting ultimately fatal comorbidity (OR, 2.92; 95%CI, 1.71-4.98, P = 0.0001), refractory CSE (OR, 2.19; 95%CI, 1.43-3.36, P = 0.0004), cerebral insult as the cause of CSE (OR, 2.75; 95%CI, 1.75-4.27, P < 0.0001), and Logistic Organ Dysfunction score ≥ 3 at ICU admission (OR, 2.08; 95%CI, 1.37-3.15, P = 0.0006). A preadmission GOS score of 3 was not associated with a functional decline during the first year (OR, 0.61; 95%CI, 0.31-1.22, P = 0.17).

SIGNIFICANCE

Preadmission functional status in adult patients with CSE is not independently associated with a functional decline during the first postadmission year. This finding may help physicians make ICU admission decisions and adult patients write advance directives.

STUDY REGISTRATION

#NCT03457831.

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.

When is it time for palliative and end-of-life care in status epilepticus?

Status epilepticus (SE) is a neurological emergency characterized by high rates of short-term and long-term morbidity and mortality. Status epilepticus seems to be a marker of the severity of other underlying conditions rather than a determinant of death on its own. Careful diagnosis and acute treatment of complications and causes of death to SE or its underlying etiology will enable the differentiation of SE patients that would benefit from different levels of treatment intensity. All SE patients should be treated actively with first- and second-line drugs as early as possible. For cases in which seizures continue after second-line treatment, the current guidelines fail to offer possibilities other than the active path with general anesthesia and intensive care unit (ICU) care. However, the intensity of care should be evaluated before starting ICU care or in unclear cases with the time-limited trial at ICU. There are now multiple possibilities for specialty palliative SE care that include sequential and add-on use of second-line drugs and palliative sedation at the ward. If ICU care is prolonged, the patient's status needs to be constantly re-evaluated and communicated to the family. When patients exhibit multiple predictors of mortality and poor functional outcomes, they should be allowed to have a natural death in a peaceful environment without unnecessarily prolonged suffering. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

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.

Specific characteristics and current diagnostic and treatment modalities performance of super refractory status epilepticus in children: A comparative study

OBJECTIVE

Super-refractory status epilepticus (SRSE) is associated with significant morbidity and mortality in children. We explored the clinical spectrum, specific characteristics, and outcome in SRSE patients admitted in a pediatric intensive care unit (PICU) and investigated how well current diagnostic or treatment modalities perform compared to Status Epilepticus (SE) and Refractory SE (RSE) patients.

METHODS

Retrospective analysis of PICU patients admitted with convulsive SE during 2009-2019. Eighty-six patients were classified as SE, RSE, and SRSE. New-onset RSE (NORSE) and febrile infection-related epilepsy syndrome (FIRES) were also identified. Functional outcome was evaluated by the modified Rankin scale.

RESULTS

Patients with SRSE (n = 20) had longer weaning off anesthetics (p = 0.014), length of stay, mechanical ventilation duration, higher illness severity scores, and poorer outcome compared to SE (n = 13) or RSE (n = 53) patients (all p < 0.001). Diagnosis, mainly expressed by high prevalence of NORSE (n = 13) and FIRES (n = 9), was independently associated with SRSE (p = 0.024). Abnormal MRI findings (p = 0.005), and epilepsy-related pathogenic variants identified by whole-exome sequencing (WES) were mostly found in SRSE patients. Compared to intravenous immunoglobulins and steroid pulses, plasmapheresis and ketogenic diet, more often used in SRSE (p < 0.01), contributed better to seizure control. Only SRSE (AUROC > 0.80, 95% CI = 0.68-0.94, p < 0.001) and diagnosis (AUROC > 0.70, 95% CI = 0.55-0.83, p = 0.02) could predict a poor outcome.

CONCLUSION

The majority of SRSE patients are characterized by considerable functional decline and morbidity. WES analysis may reveal epilepsy-related pathogenic variants while early aggressive immunotherapy and/or ketogenic diet might prove beneficial. Multicenter studies for prediction models of outcome are needed.

Frequency and Types of Complications Encountered in Patients With Nonconvulsive Status Epilepticus in the Neurological ICU: Impact on Outcome

Objectives. The frequency and types of complications in patients with nonconvulsive status epilepticus (NCSE) who are followed up in the intensive care unit (ICU), and the impact of these complications on outcome are not well-known. We investigated the complications and their effects on prognosis in NCSE patients. Methods. After reviewing the video-EEG monitoring (VEEGM) reports of all the consecutive patients who were followed up in our ICU between 2009 and 2019, we identified two groups of patients: 1-patients with NCSE (study group) and 2-patients who underwent VEEGM for possible NCSE but did not have ictal recordings (no-NCSE group). Electronic health records were reviewed to identify demographic and clinical data, duration of ICU care, medical and surgical complications, pharmacologic treatment, and outcome. These parameters were compared statistically between the groups. We also investigated the parameters affecting prognosis at discharge. Results. Thirty-two patients with NCSE comprised the study group. Infection developed in 84%. More than half were intubated, had tracheostomy or percutaneous endoscopic gastrostomy application. Refractory NCSE was associated with significantly more frequent complications and worse outcome. There was a higher tendency of infections in the study group (P = .059). Higher organ failure scores and prolonged stay in ICU predicted worse outcome (P < .05). Conclusion. The frequency of complications in patients with NCSE who are cared for in the ICU is considerable. Most of the complications are similar to the other patients in ICU, except for the higher frequency of infections. Increased physician awareness about modifiable parameters and timely interventions might help improve prognosis.

Allopregnanolone and perampanel as adjuncts to midazolam for treating diisopropylfluorophosphate-induced status epilepticus in rats

Combinations of midazolam, allopregnanolone, and perampanel were assessed for antiseizure activity in a rat diisopropylfluorophosphate (DFP) status epilepticus model. Animals receiving DFP followed by atropine and pralidoxime exhibited continuous high-amplitude rhythmical electroencephalography (EEG) spike activity and behavioral seizures for more than 5 hours. Treatments were administered intramuscularly 40 min after DFP. Seizures persisted following midazolam (1.8 mg/kg). The combination of midazolam with either allopregnanolone (6 mg/kg) or perampanel (2 mg/kg) terminated EEG and behavioral status epilepticus, but the onset of the perampanel effect was slow. The combination of midazolam, allopregnanolone, and perampanel caused rapid and complete suppression of EEG and behavioral seizures. In the absence of DFP, animals treated with the three-drug combination were sedated but not anesthetized. Animals that received midazolam alone exhibited spontaneous recurrent EEG seizures, whereas those that received the three-drug combination did not, demonstrating antiepileptogenic activity. All combination treatments reduced neurodegeneration as assessed with Fluoro-Jade C staining to a greater extent than midazolam alone, and most reduced astrogliosis as assessed by GFAP immunoreactivity but had mixed effects on markers of microglial activation. We conclude that allopregnanolone, a positive modulator of the GABAA receptor, and perampanel, an AMPA receptor antagonist, are potential adjuncts to midazolam in the treatment of benzodiazepine-refractory organophosphate nerve agent-induced status epilepticus.

Factors affecting mortality of refractory status epilepticus

OBJECTIVE

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

MATERIAL-METHOD

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

RESULTS

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

DISCUSSION/CONCLUSION

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

Incidence of the different stages of status epilepticus in Eastern Finland: A population-based study

OBJECTIVE

The objective of this study was to determine the incidence in Eastern Finland of the different stages of status epilepticus (SE): 1) at the early stage of SE (a prolonged seizure lasting over 5 min);, 2) refractory SE (RSE), and 3) super-refractory SE (SRSE).

METHODS

Firstly, we conducted a retrospective study on the incidence and outcome of intensive care unit (ICU)-treated RSE and SRSE in the adult population (≥16 years) in Kuopio University Hospital (KUH)'s special care responsibility area (840,000 inhabitants). Secondly, we conducted a prospective study using the International League Against Epilepsy (ILAE)'s new definition for SE (prolonged seizures lasting over 5 min), in adult (≥16 years) patients in the KUH municipality district (North Savo, 248,000 inhabitants).

RESULTS

The retrospective study on ICU-treated RSE and SRSE from 2010 to 2012 identified 75 patients with RSE, of whom 21% were treated as SRSE, resulting in an annual age-adjusted incidence of ICU-treated RSE of 3.0/100,000 (95% confidence interval [CI]: 2.4-3.8) and 0.6/100,000 (95% CI: 0.4-1.0) for SRSE. In the prospective study of early stage SE (seizures lasting over 5 min), we identified 151 consecutive episodes during the 9-month study period in 2015, corresponding to an annual age-adjusted incidence of 81.1/100,000 (95% CI: 75.8-87.0). In this study, 11 seizure episodes became refractory, resulting in an age-adjusted incidence of RSE of 6.0/100,000 (95% CI: 3.4-10.4), of which seven were treated in the ICU [3.8/100,000 (95% CI: 1.8-7.8)], four were treated palliatively [2.2/100,000 (95% CI: 0.82-5.7)], and two evolved to SRSE [1.1/100,000 (95% CI: 0.3-4.3)].

CONCLUSIONS

The new ILAE 2015 definition of SE resulted in a four-fold increase in incidence of SE compared to the earlier 30-min definition reported earlier in Europe. In the epidemiology of RSE, the incidence of ICU-treated RSE, palliatively treated RSE, and SRSE needs to be separated. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures.

Management of prolonged epileptic seizures and status epilepticus in palliative care patients

Prolonged seizures and status epilepticus (SE) are relevant problems in palliative care. Timely recognition and effective early treatment with first- and second-line antiepileptic drugs (AEDs) may prevent unnecessary hospitalizations. Seizures should be recognized and addressed like any other symptom that causes discomfort or reduces quality of life. Use of alternative AED administration routes (buccal, intranasal, or subcutaneous) may offer possibilities for effective and individualized AED therapy, even during the last days of life. In hospice or home care, however, also intravenous treatment is possible via vascular access devices for long-term use. Aggressive unlimited intensive care unit (ICU) treatment of refractory SE in palliative patients is mostly not indicated. At worst, intensive care can be futile and possibly harmful: death in the ICU is often preceded by long and aggressive treatments. Metastatic cancer, old age, high severity of acute illness, overall frailty, poor functional status before hospital admission, and the presence of severe comorbidities all increase the probability of poor outcome of intensive care. When several of these factors are present, consideration of withholding intensive care may be in the patient's best interests. Anticipated outcomes influence patients' preferences. A majority of patients with a limited life expectancy because of an incurable disease would not want aggressive treatment, if the anticipated outcome was survival but with severe functional impairment. Doctors' perceptions about their patients' wishes are often incorrect, and therefore, advance care planning including seizure management should be done early in the course of the disease. This article is part of the Special Issue "Proceedings of the 7th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures".

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.

Admission patterns and survival from status epilepticus in critical care in the UK: an analysis of the Intensive Care National Audit and Research Centre Case Mix Programme database

BACKGROUND AND PURPOSE

Factors influencing the outcome after the critical care unit (CCU) for patients with status epilepticus (SE) are poorly understood. Survival for these patients was examined to establish (i) whether the risk of mortality has changed over time and (ii) whether admission to different unit types affects mortality risk over and above other risk factors.

METHODS

The Intensive Care National Audit and Research Centre database and the Case Mix Programme database (January 2001 to December 2016) were analysed. Units were defined as neuro-CCU (NCCU), general CCU with 24-h neurological support (GCCU-N) or general CCU with limited neurological support (GCCU-L).

RESULTS

There were 35 595 CCU cases of SE with a 3-fold increase over time (4739 in 2001-2004 to 14 166 in 2013-2016). More recent admissions were older and were more often unsedated on admission. Mortality declined for all units although this was more marked for NCCUs (8.1% in 2001-2004 to 4.4% in 2013-2016 compared to 5.1% and 4.1% for GCCU-L). Acute hospital mortality was two to three times higher than CCU mortality although this has also declined with time. GCCU-L appeared to have lower mortality than NCCUs (odds ratio 0.84, 95% confidence interval 0.72, 0.98) but after post hoc adjustment for case mix there were no differences. Older age and markers of seriousness of morbidity were all associated with increased mortality risk.

CONCLUSIONS

The number of patients admitted to a CCU for SE is rising but critical care and acute hospital mortality is decreasing. Patients treated in an NCCU have higher mortality but this is explicable by more severe underlying disease.

[Management of refractory and super-refractory status epilepticus]

If status epilepticus continues despite the use of intravenous antiepileptic drugs or narcotics, it is called "refractory" or "super-refractory" status epilepticus (RSE, SRSE). Prolonged seizure activity is associated with neuronal damage, systemic complications and mortality rates of up to 50%, especially in generalized tonic clonic seizure types. In order to terminate the status, several rescue interventions with drugs and other measures are available. However, their evidence base is low because the effectiveness of the measures was almost exclusively derived from case reports and case series. In individual cases, a good outcome is possible even after several months of ongoing SRSE.

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.

fNIRS improves seizure detection in multimodal EEG-fNIRS recordings

In the context of epilepsy monitoring, electroencephalography (EEG) remains the modality of choice. Functional near-infrared spectroscopy (fNIRS) is a relatively innovative modality that cannot only characterize hemodynamic profiles of seizures but also allow for long-term recordings. We employ deep learning methods to investigate the benefits of integrating fNIRS measures for seizure detection. We designed a deep recurrent neural network with long short-term memory units and subsequently validated it using the CHBMIT scalp EEG database-a compendium of 896 h of surface EEG seizure recordings. After validating our network using EEG, fNIRS, and multimodal data comprising a corpus of 89 seizures from 40 refractory epileptic patients was used as model input to evaluate the integration of fNIRS measures. Following heuristic hyperparameter optimization, multimodal EEG-fNIRS data provide superior performance metrics (sensitivity and specificity of 89.7% and 95.5%, respectively) in a seizure detection task, with low generalization errors and loss. False detection rates are generally low, with 11.8% and 5.6% for EEG and multimodal data, respectively. Employing multimodal neuroimaging, particularly EEG-fNIRS, in epileptic patients, can enhance seizure detection performance. Furthermore, the neural network model proposed and characterized herein offers a promising framework for future multimodal investigations in seizure detection and prediction.

Long-term outcomes of status epilepticus: A critical assessment

We reviewed 37 studies reporting long-term outcomes after a status epilepticus (SE) episode in pediatric and adult populations. Study design, length of follow-up, outcome measures, domains investigated (mortality, SE recurrence, subsequent epilepsy, cognitive outcome, functional outcome, or quality of life), and predictors of long-term outcomes are summarized. Despite heterogeneity in the design of prior studies, overall risk of poor long-term outcome after SE is high in both children and adults. Etiology is the main determinant of outcome, and the effect of age or SE duration is often difficult to distinguish from the underlying cause. The effect of the treatment on long-term outcome after SE is still unknown.

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.

The Clinical Characteristics and Prognostic Analysis of Status Epilepticus in Northeast China

OBJECTIVE

Status epilepticus (SE) is a neurological emergency that may cause severe neurological deficiency and even death. The aim of this study was to analyze the clinical characteristics and prognosis of SE in northeast China. Additionally, the etiology and classification are discussed.

MATERIALS AND METHODS

We retrospectively collected the clinical profiles of patients diagnosed with SE in the Epilepsy Center of Jilin University between January 2011 and May 2015. The causes and clinical courses were investigated. The individuals were followed up by visit or telephone, and the prognoses were analyzed.

RESULTS

A total of 223 patients with SE were enrolled, including 134 cases with non-refractory SE (NRSE) and 89 cases with refractory or super-refractory SE (RSE/SRSE). Fifteen patients died during hospitalization, yielding a mortality of 6.73%; 11 of them succumbed to multiple organ dysfunction syndrome (MODS). Statistical analysis showed significant differences in age, family history of epilepsy, and the incidence of non-convulsive SE (NCSE) between the NRSE group and RSE/SRSE group (p < 0.05). We found no significant differences in the causes of SE (central nervous system infection, autoimmune encephalitis, and epilepsy) between these 2 groups.

CONCLUSION

In northeast China, SE is associated with relatively lower mortality, and MODS is the major cause of death. Older age and NCSE are risk factors predicting potential progression to RSE. Central nervous system infection, autoimmune encephalitis, and epilepsy were common causes of SE, but there was no significant association between any of these causes and the occurrence of RSE.