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

Status epilepticus: Is there a Stage 1 plus?

In status epilepticus (SE), "time is brain." Currently, first-line therapy consists of benzodiazepines (BDZs) and SE is classified by the response to treatment; stage 2 or established SE is defined as "BDZ-resistant SE." Nonetheless, this classification does not always work, especially in the case of prolonged convulsive SE, where many molecular changes occur and γ-aminobutyric acid signaling becomes excitatory. Under these circumstances, BDZ therapy might not be optimal, and might be possibly detrimental, if given alone; as the duration of SE increases, so too does BDZ resistance. Murine models of SE showed how these cases might benefit more from synergistic combined therapy from the start. The definition of Stage 1 plus is suggested, as a stage requiring combined therapy from the start, which includes prolonged SE with seizure activity going on for >10 min, the time that marks the disruption of receptor homeostasis, with increased internalization. This specific stage might require a synergistic approach from the start, with a combination of first- and second-line treatment.

Electroconvulsive Therapy in Refractory and Super-Refractory Status Epilepticus in Adults: A Scoping Review

BACKGROUND

Electroconvulsive therapy (ECT) has been suggested as a treatment option for refractory status epilepticus (RSE) and super-refractory status epilepticus (SRSE).

OBJECTIVE

The objective of this scoping review was to conduct an extensive literature review on the role of ECT as a treatment option for RSE and SRSE.

METHODS

We searched Ovid MEDLINE and Scopus for journal articles from database inception until February 2024. Articles were then selected based on predetermined inclusion and exclusion criteria.

RESULTS

We identified five retrospective case series with 28 adult patients receiving ECT for RSE or SRSE. ECT was administered within 3-70 days (mean 20 days) after the development of SE, and the mean number of ECT courses ranged from 1 to 12 sessions for each patient. ECT was administered in fixed or titrated doses. A total of 20 out of 28 patients (71%) showed clinical improvement, with two (7%) having complete cessation of seizures. It is essential to note that given the lack of control, there could be overreporting of clinical improvement in these studies. 11 patients (39%) were reported as deceased due to causes that were not directly related to ECT treatment. Four patients (14%) reported adverse effects of ECT, including memory, concentration, and/or cognitive impairment.

CONCLUSIONS

There are level-4 Oxford Centre for Evidence-Based Medicine evidence and low-level Grading of Recommendations Assessment Development and Education evidence that suggest ECT as a treatment option for RSE and SRSE. In light of the limitations of the existing evidence, clinicians should carefully consider individual patients' clinical contexts when deciding on the appropriateness of ECT as a treatment option. Further research, including prospective studies with controlled designs, is needed to elucidate the efficacy, safety, and optimal regime of ECT in the management of RSE and SRSE.

Treating status epilepticus in adults

This clinical review examines the treatment of status epilepticus, a condition in which epileptic seizures are prolonged and pose a significant risk of brain damage and death. International guidelines recommend the use of benzodiazepines as first-line treatment, and these should be administered promptly and in appropriate doses. Second-line treatment involves the use of high-dose anti-seizure medications to stop and prevent seizures. If seizure activity persists, general anaesthesia should be administered as soon as possible. All neurological hospital departments should have established and rehearsed protocols for treating status epilepticus.

Prognostic value of Salzburg nonconvulsive status epilepticus criteria: The SACE score

OBJECTIVE

This study was undertaken to investigate the association between the Salzburg nonconvulsive status epilepticus (NCSE) criteria and in-hospital outcome, to determine the predictive accuracy of the Status Epilepticus Severity Score (STESS), modified STESS (mSTESS), Epidemiology-Based Mortality Score in Status Epilepticus (EMSE), and END-IT (encephalitis, NCSE, diazepam resistance, imaging features, and tracheal intubation) in NCSE patients, and to develop a new prognostic score specifically designed for NCSE patients.

METHODS

Clinical and electroencephalographic (EEG) data of adult patients treated for NCSE from 2020 to 2023 were retrospectively assessed. Age, sex, modified Rankin Scale at admission, comorbidities, history of seizures, etiology, status epilepticus type, and outcome were collected from the patients' digital charts. EEG data were assessed and categorized applying the Salzburg NCSE criteria. In-hospital death was defined as the primary outcome.

RESULTS

A total of 116 NCSE patients were included. Multivariable logistic regression revealed that Salzburg NCSE criterion A2 (ictal morphological, spatial, and temporal evolution) was associated with in-hospital survival. The best STESS cutoff was ≥4 (sensitivity = .62, specificity = .69, accuracy = 67%). mSTESS ≥ 5 reached a sensitivity of .68, a specificity of .57, and an overall accuracy of 60%, EMSE ≥ 64 a sensitivity of .82, a specificity of .39, and an overall accuracy of 52%, and END-IT ≥ 3 a sensitivity of .65, a specificity of .44, and an overall accuracy of 50%. Through a hypothesis-generating approach, we developed the SACE score, which integrates EEG features (criterion A2) with patient age (with a 75-year cutoff), history of seizures, and level of consciousness. With a cutoff of ≥3, it had a sensitivity of .77, a specificity of .74, and an overall accuracy of 76%, performing better than other prognostic scores.

SIGNIFICANCE

We developed a new user-friendly scoring system, the SACE score, which integrates EEG features with other established outcome-related variables assessable in early stages, to assist neurologists and neurointensivists in making more tailored prognostic decisions for NCSE patients.

Performance evaluation of metaheuristics-tuned recurrent neural networks for electroencephalography anomaly detection

Electroencephalography (EEG) serves as a diagnostic technique for measuring brain waves and brain activity. Despite its precision in capturing brain electrical activity, certain factors like environmental influences during the test can affect the objectivity and accuracy of EEG interpretations. Challenges associated with interpretation, even with advanced techniques to minimize artifact influences, can significantly impact the accurate interpretation of EEG findings. To address this issue, artificial intelligence (AI) has been utilized in this study to analyze anomalies in EEG signals for epilepsy detection. Recurrent neural networks (RNNs) are AI techniques specifically designed to handle sequential data, making them well-suited for precise time-series tasks. While AI methods, including RNNs and artificial neural networks (ANNs), hold great promise, their effectiveness heavily relies on the initial values assigned to hyperparameters, which are crucial for their performance for concrete assignment. To tune RNN performance, the selection of hyperparameters is approached as a typical optimization problem, and metaheuristic algorithms are employed to further enhance the process. The modified hybrid sine cosine algorithm has been developed and used to further improve hyperparameter optimization. To facilitate testing, publicly available real-world EEG data is utilized. A dataset is constructed using captured data from healthy and archived data from patients confirmed to be affected by epilepsy, as well as data captured during an active seizure. Two experiments have been conducted using generated dataset. In the first experiment, models were tasked with the detection of anomalous EEG activity. The second experiment required models to segment normal, anomalous activity as well as detect occurrences of seizures from EEG data. Considering the modest sample size (one second of data, 158 data points) used for classification models demonstrated decent outcomes. Obtained outcomes are compared with those generated by other cutting-edge metaheuristics and rigid statistical validation, as well as results' interpretation is performed.

Charting the Progress of Epilepsy Classification: Navigating a Shifting Landscape

Epilepsy, a neurological disorder characterized by recurrent seizures, has witnessed a remarkable transformation in its classification paradigm, driven by advances in clinical understanding, neuroimaging, and molecular genetics. This narrative review navigates the dynamic landscape of epilepsy classification, offering insights into recent developments, challenges, and the promising horizon. Historically, epilepsy classification relied heavily on clinical observations, categorizing seizures based on their phenomenology and presumed etiology. However, the field has profoundly shifted from a symptom-based approach to a more refined, multidimensional system. One pivotal aspect of this evolution is the integration of neuroimaging techniques, particularly magnetic resonance imaging (MRI) and functional imaging modalities. These tools have unveiled the intricate neural networks implicated in epilepsy, facilitating the identification of distinct brain abnormalities and the categorization of epilepsy subtypes based on structural and functional findings. Furthermore, the role of genetics has become increasingly prominent in epilepsy classification. Genetic discoveries have not only unraveled the molecular underpinnings of various epileptic syndromes but have also provided valuable diagnostic and prognostic insights. This narrative review delves into the expanding realm of genetic testing and its impact on tailoring treatment strategies to individual patients. As the classification landscape evolves, there are accompanying challenges. The narrative review underscores the transformative potential of artificial intelligence and machine learning in epilepsy classification. These technologies hold promise in automating the analysis of complex neuroimaging and genetic data, offering enhanced accuracy and efficiency in epilepsy diagnosis and classification. In conclusion, navigating the shifting landscape of epilepsy classification is a journey marked by progress, complexity, and the prospect of improved patient care. We are charting a course toward more precise diagnoses and tailored treatments by embracing advanced neuroimaging, genetics, and innovative technologies. As the field continues to evolve, collaborative efforts and a holistic understanding of epilepsy's diverse manifestations will be instrumental in harnessing the full potential of this dynamic landscape.

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.

Pediatric Status Epilepticus: Treat Early and Avoid Delays

Pediatric convulsive status epilepticus (cSE) is a neurologic emergency with potential for morbidity and mortality. Rapid treatment and escalation of therapies to achieve early seizure control is paramount in preventing complications and providing the best patient outcomes. Although guidelines recommend early treatment, cessation of out-of-hospital SE is undermined by treatment delay and inadequate dosing. Logistical challenges include prompt seizure recognition, first-line benzodiazepine (BZD) availability, comfort and expertise in administration of BZD, and timely arrival of emergency personnel. In-hospital, SE onset is additionally impacted by delays to first- and second-line treatment and availability of resources. This review presents an evidence-based, clinically oriented review of pediatric cSE, including its definitions and treatments. It provides evidence and rationale for timely treatment of first-line BZD treatment followed by prompt escalation to second-line antiseizure medication therapies for established SE. Treatment delays and barriers to care are discussed, with practical considerations for opportunities for areas of improvement in the initial treatment of cSE.

A practical approach to in-hospital management of new-onset refractory status epilepticus/febrile infection related epilepsy syndrome

New-onset refractory status epilepticus (NORSE) is "a clinical presentation, not a specific diagnosis, in a patient without active epilepsy or other preexisting relevant neurological disorder, with new onset of refractory status epilepticus without a clear acute or active structural, toxic, or metabolic cause." Febrile infection related epilepsy syndrome (FIRES) is "a subcategory of NORSE that requires a prior febrile infection, with fever starting between 2 weeks and 24 h before the onset of refractory status epilepticus, with or without fever at the onset of status epilepticus." These apply to all ages. Extensive testing of blood and CSF for infectious, rheumatologic, and metabolic conditions, neuroimaging, EEG, autoimmune/paraneoplastic antibody evaluations, malignancy screen, genetic testing, and CSF metagenomics may reveal the etiology in some patients, while a significant proportion of patients' disease remains unexplained, known as NORSE of unknown etiology or cryptogenic NORSE. Seizures are refractory and usually super-refractory (i.e., persist despite 24 h of anesthesia), requiring a prolonged intensive care unit stay, often (but not always) with fair to poor outcomes. Management of seizures in the initial 24-48 h should be like any case of refractory status epilepticus. However, based on the published consensus recommendations, the first-line immunotherapy should begin within 72 h using steroids, intravenous immunoglobulins, or plasmapheresis. If there is no improvement, the ketogenic diet and second-line immunotherapy should start within seven days. Rituximab is recommended as the second-line treatment if there is a strong suggestion or proof of an antibody-mediated disease, while anakinra or tocilizumab are recommended for cryptogenic cases. Intensive motor and cognitive rehab are usually necessary after a prolonged hospital stay. Many patients will have pharmacoresistant epilepsy at discharge, and some may need continued immunologic treatments and an epilepsy surgery evaluation. Extensive research is in progress now via multinational consortia relating to the specific type(s) of inflammation involved, whether age and prior febrile illness affect this, and whether measuring and following serum and/or CSF cytokines can help determine the best treatment.

Mortality, and life expectancy in Epilepsy and Status epilepticus-current trends and future aspects

Patients with epilepsy carry a risk of premature death which is on average two to three times higher than in the general population. The risk of death is not homogenously distributed over all ages, etiologies, and epilepsy syndromes. People with drug resistant seizures carry the highest risk of death compared to those who are seizure free, whose risk is similar as in the general population. Most of the increased risk is directly related to the cause of epilepsy itself. Sudden unexplained death in epilepsy patients (SUDEP) is the most important cause of epilepsy-related deaths especially in the young and middle-aged groups. Population based studies with long-term follow up demonstrated that the first years after diagnosis carry the highest risk of death, while in the later years the mortality decreases. Improved seizure control and being exposed to a specialized comprehensive care centre may help to reduce the risk of death in patients with epilepsy. The mortality of status epilepticus is substantially increased with case fatality rates between 4.6% and 39%, depending on its cause and duration, and the age of the population studied. The epidemiological data on overall and cause specific mortality as well as their determinants and risk factors are critically reviewed and methodological issues pertinent to the studies on mortality of epilepsy and Status epilepticus are discussed.

Clinico-biological markers for the prognosis of status epilepticus in adults

Prediction of mortality, functional outcome and recovery after status epilepticus (SE) is a challenge. Biological and clinical markers have been proposed to reflect the brain injury or to monitor critical ill patients' severity. The aim of this study was to characterize short-term and long-term prognostic factors for SE patients hospitalized in intensive care unit. Patient's outcome was assessed using the modified Rankin Scale at discharge and after 6-12 months. We first assessed the univariate prognosis significance of 51 clinical, demographic or biochemical markers. Next, we built multivariate clinico-biological models by combining most important factors. Statistical models' performances were compared to those of two previous published scales STESS and mSTESS. Eighty-one patients were enrolled. Thirty-five patients showed a steady state while 46 patients clinically worsened at discharge: 14 died, 14 had persistent disability at 6-12 months and 18 recovered. Logistic regression analysis revealed that clinical markers (SE refractoriness, SE duration, de novo SE) were significant independent predictors of worsening while lipids markers and progranulin better predicted mortality. The association of clinico-biological variables allowed to accurately predict worsening at discharge (AUC > 0.72), mortality at discharge (AUC 0.83) and recovery at long-term (AUC 0.89). Previous scales provided lower prediction for worsening (AUC 0.63, STESS; 0.53, mSTESS) and mortality (AUC 0.56, STESS; 0.62, mSTESS) (p < 0.001). We proposed new clinico-biological models with a strong discrimination power for prediction of short- and long-term outcome of hospitalized status epilepticus patients. Their implementation in electronic devices may enhance their clinical liability.