Markers in Status Epilepticus Prognosis

Periodic discharges and status epilepticus: A critical reappraisal

OBJECTIVE

Periodic Discharges (PDs) in Status Epilepticus (SE) are historically related to negative outcome, and the Epidemiology-based Mortality Score in SE (EMSE) identifies PDs as an EEG feature associated with unfavorable prognosis. However, supportive evidence is conflicting. This study aims to evaluate the prognostic significance of interictal PDs during and following SE.

METHODS

All 2020-2023 non-hypoxic-ischemic SE patients with available EEG during SE were retrospectively assessed. Interictal PDs during SE (SE-PDs) and PDs occurring 24-72 h after SE resolution (post-SE-PDs) were examined. In-hospital death was defined as the primary outcome.

RESULTS

189 SE patients were finally included. SE-PDs were not related to outcome, while post-SE-PDs were related to poor prognosis confirmed after multiple regression analysis. EMSE global AUC was 0.751 (95%CI:0.680-0.823) and for EMSE-64 cutoff sensitivity was 0.85, specificity 0.52, accuracy 63%. We recalculated EMSE score including only post-SE-PDs. Modified EMSE (mEMSE) global AUC was 0.803 (95%CI:0.734-0.872) and for mEMSE-64 cutoff sensitivity was 0.84, specificity 0.68, accuracy 73%.

CONCLUSION

Interictal PDs during SE were not related to outcome whereas PDs persisting or appearing > 24 h after SE resolution were strongly associated to unfavorable prognosis. EMSE performed well in our cohort but considering only post-SE-PDs raised specificity and accuracy for mEMSE64 cutoff.

SIGNIFICANCE

This study supports the utility of differentiating between interictal PDs during and after SE for prognostic assessment.

Emergent Management of Status Epilepticus

OBJECTIVE

Status epilepticus is a neurologic emergency that can be life- threatening. The key to effective management is recognition and prompt initiation of treatment. Management of status epilepticus requires a patient-specific-approach framework, consisting of four axes: (1) semiology, (2) etiology, (3) EEG correlate, and (4) age. This article provides a comprehensive overview of status epilepticus, highlighting the current treatment approaches and strategies for management and control.

LATEST DEVELOPMENTS

Administering appropriate doses of antiseizure medication in a timely manner is vital for halting seizure activity. Benzodiazepines are the first-line treatment, as demonstrated by three randomized controlled trials in the hospital and prehospital settings. Benzodiazepines can be administered through IV, intramuscular, rectal, or intranasal routes. If seizures persist, second-line treatments such as phenytoin and fosphenytoin, valproate, or levetiracetam are warranted. The recently published Established Status Epilepticus Treatment Trial found that all three of these drugs are similarly effective in achieving seizure cessation in approximately half of patients. For cases of refractory and super-refractory status epilepticus, IV anesthetics, including ketamine and γ-aminobutyric acid-mediated (GABA-ergic) medications, are necessary. There is an increasing body of evidence supporting the use of ketamine, not only in the early phases of stage 3 status epilepticus but also as a second-line treatment option.

ESSENTIAL POINTS

As with other neurologic emergencies, "time is brain" when treating status epilepticus. Antiseizure medication should be initiated quickly to achieve seizure cessation. There is a need to explore newer generations of antiseizure medications and nonpharmacologic modalities to treat status epilepticus.

Metabolomic changes in adults with status epilepticus: A human case-control study

OBJECTIVE

Status epilepticus (SE) is a life-threatening prolonged epileptic seizure that affects ~40 per 100 000 people yearly worldwide. The persistence of seizures may lead to excitotoxic processes, neuronal loss, and neuroinflammation, resulting in long-term neurocognitive and functional disabilities. A better understanding of the pathophysiological mechanisms underlying SE consequences is crucial for improving SE management and preventing secondary neuronal injury.

METHODS

We conducted a comprehensive untargeted metabolomic analysis, using liquid chromatography coupled with high-resolution mass spectrometry (LC-HRMS), on plasma and cerebrospinal fluid (CSF) samples from 78 adult patients with SE and 107 control patients without SE, including 29 with CSF for both groups. The metabolomic fingerprints were compared between patients with SE and controls. Metabolites with differences in relative abundances that could not be attributed to treatment or nutrition provided in the intensive care unit were isolated. Enrichment analysis was performed on these metabolites to identify the most affected pathways.

RESULTS

We identified 76 metabolites in the plasma and 37 in the CSF that exhibited differential expression in patients with SE compared to controls. The enrichment analysis revealed that metabolic dysregulations in patients with SE affected primarily amino acid metabolism (including glutamate, alanine, tryptophan, glycine, and serine metabolism), pyrimidine metabolism, and lipid homeostasis. Specifically, patients with SE had elevated levels of pyruvate, quinolinic acid, and keto butyric acid levels, along with lower levels of arginine, N-acetylaspartylglutamate (NAAG), tryptophan, uracil, and uridine. The tryptophan kynurenine pathway was identified as the most significantly altered in SE, resulting in the overproduction of quinolinic acid, an N-methyl-d-aspartate (NMDA) receptor agonist with pro-inflammatory properties.

SIGNIFICANCE

This study has identified several pathways that may play pivotal roles in SE consequences, such as the tryptophan kynurenine pathway. These findings offer novel perspectives for the development of neuroprotective therapeutics.

Personalized antiseizure medication therapy in critically ill adult patients

Precision medicine has the potential to have a significant impact on both drug development and patient care. It is crucial to not only provide prompt effective antiseizure treatment for critically ill patients after seizures start but also have a proactive mindset and concentrate on epileptogenesis and the underlying cause of the seizures or seizure disorders. Critical illness presents different treatment issues compared with the ambulatory population, which makes it challenging to choose the best antiseizure medications and to administer them at the right time and at the right dose. Since there is a paucity of information available on antiseizure medication dosing in critically ill patients, therapeutic drug monitoring is a useful tool for defining each patient's personal therapeutic range and assisting clinicians in decision-making. Use of pharmacogenomic information relating to pharmacokinetics, hepatic metabolism, and seizure etiology may improve safety and efficacy by individualizing therapy. Studies evaluating the clinical implementation of pharmacogenomic information at the point-of-care and identification of biomarkers are also needed. These studies may make it possible to avoid adverse drug reactions, maximize drug efficacy, reduce drug-drug interactions, and optimize medications for each individual patient. This review will discuss the available literature and provide future insights on precision medicine use with antiseizure therapy in critically ill adult patients.

Assessment of the relationship between generalized convulsive epilepsy and systemic inflammatory regulators: a bidirectional Mendelian randomization study

Background

Generalized convulsive epilepsy (GCE), an important subtype of epilepsy, is a syndrome of neuronal dysfunction characterized by diffuse abnormal discharge of neurons within the brain. Compounding evidence suggests a correlation between epilepsy and inflammatory factors, for instance, cyclooxygenase-2, interleukin-1β, and interleukin-6. Elevated levels of inflammatory factors have been observed in patients with epilepsy and several animal models. Therefore, inflammation may be closely associated with the pathogenesis and progression of GCE. However, the cause-and-effect relationship between the two is difficult to determine because of small sample sizes and confounding factors.

Methods

To test for causality of the 41 cytokines on GCE, we conducted a two-sample Mendelian randomization (MR) based on the largest and latest genome-wide association study (GWAS) involving 290 cases and 453,521 European controls and a GWAS meta-analysis consisting of 41 cytokines from 8,293 individuals.

Results

R confirmed a bidirectional causal link between cytokines and GCE. Genetically predicted increased levels of hepatocyte growth factor and decreased levels of eotaxin and interleukin-18 are associated with an increased risk of GCE (OR = 1.904, 95% CI = 1.019-3.561, p = 0.044; OR = 0.641, 95% CI = 0.417-0.984, p = 0.042; OR = 0.482, 95% CI = 0.251-0.927, p = 0.046). Furthermore, the presence of GCE is related to an increase in levels of multiple cytokines, such as macrophage inflammatory protein-1α, interleukin-12p70, interleukin-17, interleukin-1 receptor antagonist, and basic fibroblast growth factor (OR = 1.038, 95% CI = 1.005-1.073, p = 0.024; OR = 1.031, 95% CI = 1.009-1.054, p = 0.006; OR = 1.027, 95% CI = 1.002-1.053, p = 0.037; OR = 1.037, 95% CI = 1.003-1.072, p = 0.032; OR = 1.032, 95% CI = 1.000-1.066, p = 0.048; OR = 1.025, 95% CI = 1.003-1.048, p = 0026).

Conclusion

A bidirectional causal link existed between inflammation and GCE. Detecting significantly altered factor concentrations may be of great significance for screening GCE and predicting their occurrence. Moreover, available pharmacological treatments for GCE are focused primarily on suppressing seizures. In future, altering the concentration of these cytokines in the body through targeted anti-inflammatory therapy to modify the epileptogenic mechanism and prevent the recurrence and refractoriness of GCE may become the key to new treatments.

Clinical scores and clusters for prediction of outcomes in status epilepticus

Status epilepticus (SE) is a life-threatening condition and may have long-term negative sequelae. Short- and long-term outcomes encompass mortality, deterioration of functional status compared to baseline, refractoriness to treatment, recurrence of SE, and development of epilepsy, cognitive impairment, and behavioral disturbances. So far, the greatest amount of evidence is available for the prediction of short-term mortality. Conversely, the knowledge regarding long-term consequences among SE survivors is still scarce and several issues have not yet been resolved. The heterogeneity of SE renders the prognostication of outcomes challenging. Although aetiology is the main determinant of the outcome, different prognostic predictors have been identified. In this regard, data on group effects need to be integrated into prognostic scores to allow individual risk stratification. Importantly, many of the present scores are not designed to enable repetition to follow patient evolution. A new paradigm for the assessment of SE outcomes should consider variables that become available and/or can be retested during the course of SE. Neuroimaging findings, serum biomarkers, treatment characteristics, complications during SE, peri-ictal and postictal characteristics after SE cessation look as promising determinants of outcome and are suitable for inclusion in future models to enhance the quality and increase the reliability of prediction. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Association of Peri-ictal MRI Abnormalities With Mortality, Antiseizure Medication Refractoriness, and Morbidity in Status Epilepticus

BACKGROUND AND OBJECTIVES

Status epilepticus (SE) is a life-threatening emergency requiring a prompt assessment of patient prognosis to guide management. MRI allows the identification of peri-ictal MRI abnormalities (PMAs) and provides insight into brain structural modifications induced by SE. However, little is known about the significance of PMA in SE prognosis. The aim of this study was to determine whether PMAs are associated with an increased mortality in SE and to establish the association between PMA and refractoriness to antiseizure medications, complications encountered, and induced morbidity.

METHODS

We conducted a retrospective observational cohort study including all eligible consecutive patients over 15 years old and hospitalized with SE at Bordeaux University Hospital (France) between January 2015 and December 2019. The primary end point was in-hospital mortality. A dedicated neuroradiologic reassessment was performed, together with a comprehensive medical review assessing baseline characteristics, in-hospital death, SE characterization, drug refractoriness, and following outcome in survivors.

RESULTS

Of 307 patients included, 79 (26%) showed PMA related to SE. Demographic, functional status at baseline and median delay between SE onset and MRI examination were similar in the PMA-positive and PMA-negative groups. In-hospital death occurred in 15% (45/307) patients and was significantly higher in the PMA-positive group (27%, 21/79 vs 11%, 24/228; p < 0.001). In multivariate analysis, the presence of PMA (odds ratio [OR] 2.86, 95% CI 1.02-8.18; p = 0.045), together with SE duration (OR 1.01, 95% CI 1.01-1.02; p = 0.007), older age at SE onset (OR 1.05, 95% CI 1.01-1.09; p = 0.013), preexisting ultimately fatal comorbidity (OR 4.01, 95% CI 1.56-10.6; p = 0.004), and acute lesional SE etiology (OR 3.74, 95% CI 1.45-10.2; p = 0.007) were independent predictors associated with in-hospital death. Patients with PMA had a higher risk of refractory SE (71 vs 33%, p < 0.001). Among survivors, delayed-onset epilepsy (40% vs 21%, p = 0.009) occurred more frequently in the PMA-positive group.

DISCUSSION

PMA-positive cases had a higher mortality rate in the largest cohort so far to assess the prognosis value of PMA in SE. As a noninvasive and easily available tool, PMA represents a promising structural biomarker for developing a personalized approach to prognostication in patients with SE receiving MRI.

Repurposing of cholesterol-lowering agents in status epilepticus: A neuroprotective effect of simvastatin

The increase of cholesterol synthesis after a status epilepticus may lead to excitotoxic processes, neuronal loss and favor the appearance of spontaneous epileptic seizures. Lowering cholesterol content could be a neuroprotective strategy. Here, we evaluated the protective effect of simvastatin administrated daily for 14 days, after the induction of a status epilepticus by intrahippocampal injection of kainic acid in mice. The results were compared to those obtained from mice showing a kainic acid-induced status epilepticus, treated daily with a saline solution, and from mice injected with a control phosphate-buffered solution without any status epilepticus. We first assessed the antiseizure effects of simvastatin by performing video-electroencephalographic recordings during the first three hours after kainic acid injection and continuously between the fifteenth and the thirty-first days. Mice treated with simvastatin had significantly fewer generalized seizures during the first three hours without a significant effect on generalized seizures after two weeks. There was a trend for fewer hippocampal electrographic seizures after two weeks. Secondly, we evaluated the neuroprotective and anti-inflammatory effects of simvastatin by measuring the fluorescence of neuronal and astrocyte markers on the thirtieth day after status onset. We found that simvastatin reduced CA1 reactive astrocytosis, demonstrated by a significant 37% decrease in GFAP-positive cells, and that simvastatin prevented the neuronal loss in CA1, demonstrated by a significant 42% increase in the NeuN-positive cells, as compared to the findings in mice with kainic acid-induced status epilepticus treated by a saline solution. Our study confirms the interest of cholesterol-lowering agents, and in particular simvastatin, in status epilepticus and paves the way for a clinical pilot study to prevent neurological sequelae after status epilepticus. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Inflammation as Treatment Target for Status Epilepticus

BACKGROUND

Status epilepticus (SE) is a serious neurological disease that manifests as prolonged seizures that last more than 5 minutes and between such episodes, patients do not regain consciousness. It can result in cognitive defects, brain damage, or even death. It is commonly known that one of the causes can be an inflammatory process, but here we will focus on inflammation as a result of new onset refractory status epilepticus and, related to this, new promising forms of SE treatment. Particular emphasis has been focused on new-onset refractory status epilepticus (NORSE).

METHODS

Based on public research databases, drugs with anti-inflammatory activity - commonly used in different spheres of medicine - have been reviewed as potentially treating status epilepticus.

RESULTS

There is seizable clinical research suggesting that drugs that decrease inflammatory processes might be effective in terminating status epilepticus.

CONCLUSION

There is growing evidence showing that adding anti-inflammatory drugs to basic antiepileptic treatment enhances the efficiency of the therapeutic process, with special potential in NORSE cases.

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.

Quantitative EEG-Based Seizure Estimation in Super-Refractory Status Epilepticus

BACKGROUND

The objective of this study was to evaluate the accuracy of seizure burden in patients with super-refractory status epilepticus (SRSE) by using quantitative electroencephalography (qEEG).

METHODS

EEG recordings from 69 patients with SRSE (2009-2019) were reviewed and annotated for seizures by three groups of reviewers: two board-certified neurophysiologists using only raw EEG (gold standard), two neurocritical care providers with substantial experience in qEEG analysis (qEEG experts), and two inexperienced qEEG readers (qEEG novices) using only a qEEG trend panel.

RESULTS

Raw EEG experts identified 35 (51%) patients with seizures, accounting for 2950 seizures (3,126 min). qEEG experts had a sensitivity of 93%, a specificity of 61%, a false positive rate of 6.5 per day, and good agreement (κ = 0.64) between both qEEG experts. qEEG novices had a sensitivity of 98.5%, a specificity of 13%, a false positive rate of 15 per day, and fair agreement (κ = 0.4) between both qEEG novices. Seizure burden was not different between the qEEG experts and the gold standard (3,257 vs. 3,126 min), whereas qEEG novices reported higher burden (6066 vs. 3126 min).

CONCLUSIONS

Both qEEG experts and novices had a high sensitivity but a low specificity for seizure detection in patients with SRSE. qEEG could be a useful tool for qEEG experts to estimate seizure burden in patients with SRSE.

Neuron Specific Enolase, S100-beta protein and progranulin as diagnostic biomarkers of status epilepticus

Status epilepticus (SE) is a life-threatening prolonged epileptic seizure. A rapid diagnosis is fundamental to initiate antiepileptic treatment and to prevent the development of neurological sequels. Several serum and cerebrospinal fluid biomarkers have been proposed to help in the diagnosis of SE. Nevertheless, previous studies were conducted on too small patient cohorts, precluding the utilization of interesting biomarkers for the SE diagnosis. Here, we aimed to assess the ability of Neuron Specific Enolase (NSE), S100-beta protein (S100B) and progranulin to help in the diagnosis of SE in a large cohort of patients (36 control patients, 56 patients with pharmacoresistant epilepsy and 82 SE patients). Blood NSE, S100B and progranulin levels were higher in SE patients when compared with control patients or patients with pharmacoresistant epilepsy. Both NSE and progranulin levels were higher in cerebrospinal fluid from SE patients when compared with control patients. The receiver-operating characteristics curves revealed good accuracy at detecting SE for serum S100B (AUC 0.748) and plasma progranulin (AUC 0.756). The performances were lower for serum NSE (AUC 0.624). Eighty-four percent of patients with serum S100B levels above 0.09 ng/mL presented with a SE, whereas 90% of patients without SE had serum S100B levels lower than 0.09 ng/mL. Serum S100B levels were not significantly different according to SE etiology, SE semiology or SE refractoriness. Our results confirm that NSE, S100B and progranulin levels are increased after SE. We suggest that serum S100B levels might be added to clinical evaluation and electroencephalogram to identify difficult-to-diagnose form of SE.

Role of cerebrospinal fluid tau protein levels as a biomarker of brain injury in pediatric status epilepticus

BACKGROUND

Various biomarkers have been studied for predicting etiology and outcome in status epilepticus (SE); cerebrospinal fluid (CSF) total tau (t-tau) protein levels is foremost among them. Only handful of studies are available regarding role of t-tau in childhood SE.

METHODOLOGY

This prospective study was conducted in a tertiary care center of Northern India in children 6 months -12 years of age. The Cases were patients with convulsive status epilepticus (CSE) whereas Controls were patients without SE and normal CSF. The t-tau levels were done in CSF of both the groups. The outcome was assessed by GOS-E Peds score.

RESULTS

A total of 50 (62% males) cases and 15 (67% males) controls were enrolled in the study. SE was generalized in 78% cases whereas 14% had refractory SE. Most common etiology of CSE was acute symptomatic (52%), followed by prolonged febrile seizure (24%), remote symptomatic group (14%), unknown etiology (8%) and progressive disorder (2%). Case fatality rate was 10%. Poor outcome was seen in 30% cases. Median (IQR) CSF t-tau levels was significantly lower 2.6 × 10³ (0.5-9.4 × 10³) pg/ml in cases vs 10.6 × 10³ (6.0-14.2 × 10³) pg/ml in controls (p = 0.004). There was no significant correlation seen between type, duration, etiology and response to antiepileptic drugs of SE with CSF t-tau levels. Also, no significant correlation of poor sensorium, outcome of SE and critical care needs with CSF t-tau levels was noted.

CONCLUSION

CSF t-tau is not a useful diagnostic or prognostic biomarker in pediatric SE.

Epidemiology and Outcomes of Status Epilepticus

Status epilepticus (SE) is a neurological and medical emergency, defined as a condition resulting either from the failure of the mechanisms responsible of seizure self-limitation or from the initiation of mechanisms which lead to atypically prolonged seizures. Further than death, SE can have long-term consequences, including neuronal injury, depending on the type, cause and duration of seizures with severe associated disabilities. In Europe, SE shows an incidence rate ranging about 9 to 40/100,000/y. In adults, mortality of patients with SE is ~30%, and even higher (up to 40%) in refractory status epilepticus. To date, etiology, duration, presence of comorbidity, level of consciousness, semiology and age are the main clinical predictors of SE outcome.