Predictive value of S100-B and copeptin for outcomes following seizure: the BISTRO International Cohort Study

Neuro-glial degeneration in Status Epilepticus: Exploring the role of serum levels of Neurofilament light chains and S100B as prognostic biomarkers for short-term functional outcome

BACKGROUND

The last ILAE definition of Status Epilepticus (SE) highlights that the persistence of the epileptic activity per se could determine irreversible brain damages that could be responsible for long-term consequences. The measurement of neuro-glial injury biomarkers could help in the identification of those patients who will eventually develop short- and long-term consequences of SE. At present none of the already studied biomarkers has been validated to be used in everyday clinical practice. In this study, we explore the role of NfL and S100B as a prognostic biomarkers to identify patients who will develop short-term disability after an episode of SE.

METHODS

This is a retrospective assessment of the serum levels of both NfL and S100B in a cohort of 87 adult patients with SE prospectively collected in our SE registry (Modena Status Epilepticus Registry - MoSER -) at Baggiovara Civil Hospital (Modena, Italy). All samples were acquired during SE within 72 hours of SE diagnosis. The comparison groups were: healthy controls (HC, n = 27) and patients with epilepsy (PWE, n = 30). Demographic, clinical, and therapeutical information and thirty-days follow-up information regarding disability development were acquired for every included patient and analyzed in relation to NfL and S100B values.

RESULTS

Serum levels of NfL were significantly higher in SE compared to those of PWE (median 7.35 pg/ml, IQR 6.4, p < 0.001) and HC (median 6.57 pg/ml, IQR 9.1, p < 0.001); S100B serum levels were higher in SE (median 0.11 ug/L, IQR 0.18) compared to PWE (median 0.03 ug/L, IQR 0.03, p < 0.001) and HC (median 0.02 ug/L, IQR 0.008, p < 0.001). However, only NfL serum levels were found to be an independent predictor of 30 days functional outcome whereas S100B levels did not.

CONCLUSIONS

Our results suggest that NfL measurement in serum during SE could help predict the short-term functional outcome. This paper was presented at the 8th London-Innsbruck Colloquium on Status Epilepticus and Acute Seizures held in September 2022.

Serum Proteins Associated with Blood-Brain Barrier as Potential Biomarkers for Seizure Prediction

As 30% of epileptic patients remain drug-resistant, seizure prediction is vital. Induction of epileptic seizure is a complex process that can depend on factors such as intrinsic neuronal excitability, changes in extracellular ion concentration, glial cell activity, presence of inflammation and activation of the blood−brain barrier (BBB). In this study, we aimed to assess if levels of serum proteins associated with BBB can predict seizures. Serum levels of MMP-9, MMP-2, TIMP-1, TIMP-2, S100B, CCL-2, ICAM-1, P-selectin, and TSP-2 were examined in a group of 49 patients with epilepsy who were seizure-free for a minimum of seven days and measured by ELISA. The examination was repeated after 12 months. An extensive medical history was taken, and patients were subjected to a follow-up, including a detailed history of seizures. Serum levels of MMP-2, MMP-9, TIMP-1, CCL-2, and P-selectin differed between the two time points (p < 0.0001, p < 0.0001, p < 0.0001, p < 0.0001, p = 0.0035, respectively). General linear model analyses determined the predictors of seizures. Levels of MMP-2, MMP-9, and CCL-2 were found to influence seizure count in 1, 3, 6, and 12 months of observation. Serum levels of MMP-2, MMP-9, and CCL-2 may be considered potential biomarkers for seizure prediction and may indicate BBB activation.

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.

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.

Association between benzodiazepine outpatient treatment and risk of early seizure recurrence in emergency patients with seizure: A multicenter retrospective study

INTRODUCTION

Seizures are one of the most common neurological reasons for emergency department (ED) visits. The benefit of ED-initiated, short-course outpatient benzodiazepine (BZD) treatment to prevent early recurrent seizure is unknown. This study assesses the risk of early seizure recurrence in patients who were or were not started with outpatient BZD in the ED.

METHODS

This was a multicenter retrospective study conducted in eight French EDs between January 1 and December 31, 2019. All patients admitted for seizure were retrospectively screened and those discharged home from the ED were included. Patients with a history of chronic alcohol intoxication or chronic BZD therapy were excluded. Baseline characteristics, type of seizure, and 30-day outcome were retrospectively collected from the electronic health records. The primary endpoint was a return visit for seizure recurrence within 30 days. Independent factors associated with a seizure recurrence were identified using a multivariable binary logistic regression.

RESULTS

A total of 2,218 patients were included and 1,820 were analyzed. The median age was 39 years and 60% were men. Among them 82% of patients had a generalized tonic-clonic seizure and 47% of seizures were idiopathic. BZD treatment was started in 773 (42%) patients. A total of 154 (8%) patients had an early recurrence at 30 days: 68 (9%) in patients who were treated with BZD versus 86 (8%) in patients who were not (odds ratio [OR] = 1.07, 95% confidence interval [CI] = 0.71 to 1.43). In multivariable analysis, two factors were independently associated with the primary endpoint: chronic epileptic treatment (adjusted OR = 2.58, 95% CI = 1.55 to 4.37) and having had a focal seizure (adjusted OR = 2.16, 95% CI = 1.56 to 4.37).

CONCLUSION

BZD therapy was started in 42% of patients who were discharged home after ED visit for a seizure. This treatment was not an independent factor associated with the risk of return visit for seizure recurrence at 30 days.

Cerebrospinal fluid and blood biomarkers of status epilepticus

Status epilepticus is a condition resulting either from the failure of the mechanisms responsible for seizure termination or from the initiation of mechanisms that lead to abnormally prolonged seizures and require urgent administration of antiepileptic drugs. Refractory status epilepticus requires anesthetics drugs and may lead to brain injury with molecular and cellular alterations (eg, inflammation, and neuronal and astroglial injury) that could induce neurologic sequels and further development of epilepsy. Outcome scores based on demographic, clinical, and electroencephalography (EEG) condition are available, allowing prediction of the risk of mortality, but the severity of brain injury in survivors is poorly evaluated. New biomarkers are needed to predict with higher accuracy the outcome of patients admitted with status in an intensive care unit. Here, we summarize the findings of studies from patients and animal models of status epilepticus. Specific protein markers can be detected in the cerebrospinal fluid and the blood. One of the first described markers of neuronal death is the neuron-specific enolase. Gliosis resulting from inflammatory responses after status can be detected through the increase of S100-beta, or some cytokines, like the High Mobility Group Box 1. Other proteins, like progranulin may reflect the neuroprotective mechanisms resulting from the brain adaptation to excitotoxicity. These new biomarkers aim to prospectively identify the severity and development of disability, and subsequent epilepsy of patients with status. We discuss the advantages and disadvantages of each biomarker, by evaluating their brain specificity, stability in the fluids, and sensitivity to external interferences, such as hemolysis. Finally, we emphasize the need for further development and validation of such biomarkers in order to better assess patients with severe status epilepticus.

Increased Serum S100B Levels in Patients With Epilepsy: A Systematic Review and Meta-Analysis Study

Importance: Accumulating evidence suggests that serum levels of S100B may play a role in epilepsy. Objective: We performed a meta-analysis to quantitatively summarize the serum S100B data available for patients with epilepsy. Data source: Two independent researchers conducted a systematic investigation of the Harvard Hollis+, Open Gray, Clinicaltrials, Wanfangdata, and CNKI databases through Dec 6, 2018, for all studies published in English and Chinese. The search terms included S100B and calcium-binding protein B in combination with epilepsy. Study selection: Original studies and reported data from these search terms are included. Studies where data overlapped with other studies were excluded. Data extraction and synthesis: investigators extracted, pooled and analyzed data from the included studies using a fixed-effects model in the Comprehensive Meta-Analysis3.3 and R software. Main outcomes and measures: Peripheral blood levels of S100B in patients with epilepsy compared with controls. Aberrations in peripheral blood levels of S100B were hypothesized to be related to epilepsy. Results: a fixed-effects meta-analysis of all 18 studies, including 1,057 unique participants, indicated that patients with epilepsy had significantly increased peripheral blood levels of S100B compared to controls (Hedges g = 1.568, 95% CI =1.431-1.706, P < 0.001). Sensitivity analysis showed that no single study significantly influenced the overall association of peripheral blood levels of S100B and epilepsy. Most of the subgroup analyses, including those of country, assay type and publication language, demonstrated a statistically significant association between peripheral blood levels of S100B and epilepsy. Meta-regression analyses indicated that gender (regression coefficient [SE], -0.2524 [0.0641]; 95%CI, -0.3781 to -0.1267; P = 0.0001) and mean age (regression coefficient [SE], -0.1224 [0.0426]; 95% CI, -0.2058 to -0.0390; P = 0.0040) might present serum S100B reductions, but sample size, years, assay type, publication language and country did not show moderating effects on the effect sizes. Furthermore, the trim-and-fill method used to adjust for funnel plot asymmetry in our meta-analysis confirmed that a positive outcome is unlikely to be due to publication bias. Conclusion and relevance: the results of this meta-analysis provide evidence for a significant increase in serum S100B levels in patients with epilepsy. Serum S100B is the most worthwhile biomarker of epilepsy, which is helpful for the clinical diagnosis and prognosis of epilepsy.

Blood markers of cardiac stress after generalized convulsive seizures

OBJECTIVE

Generalized convulsive seizures (GCS) are associated with high demands on the cardiovascular system, thereby facilitating cardiac complications. To investigate occurrence, influencing factors, and extent of cardiac stress or injury, the alterations and time course of the latest generation of cardiac blood markers were investigated after documented GCS.

METHODS

Adult patients with refractory epilepsy who underwent video-electroencephalography (EEG) monitoring along with simultaneous one-lead electrocardiography (ECG) recordings were included. Cardiac biomarkers (cardiac troponin I [cTNI]; high-sensitive troponin T [hsTNT]; N-terminal prohormone of brain natriuretic peptide [NT-proBNP]; copeptin; suppression of tumorigenicity-2 [SST-2]; growth differentiation factor 15, [GDF-15]; soluble urokinase plasminogen activator receptor [suPAR]; and heart-type fatty acid binding protein [HFABP]) and catecholamines were measured at inclusion and at different time points after GCS. Periictal cardiac properties were assessed by analyzing heart rate (HR), HR variability (HRV), and corrected QT intervals(QTc).

RESULTS

Thirty-six GCS (6 generalized-onset tonic-clonic seizures and 30 focal to bilateral tonic-clonic seizures) were recorded in 30 patients without a history of cardiac or renal disease. Postictal catecholamine levels were elevated more than twofold. A concomitant increase in HR and QTc, as well as a decrease in HRV, was observed. Elevations of cTNI and hsTNT were found in 3 of 30 patients (10%) and 6 of 23 patients (26%), respectively, which were associated with higher dopamine levels. Copeptin was increased considerably after most GCS, whereas SST-2, HFABP, and GDF-15 displayed only subtle variations, and suPAR was unaltered in the postictal period. Cardiac symptoms did not occur in any patient.

SIGNIFICANCE

The use of more sensitive biomarkers such as hsTNT suggests that signs of cardiac stress occur in about 25% of the patients with GCS without apparent clinical symptoms. SuPAR may indicate clinically relevant troponin elevations. Copeptin could help to diagnose GCS, but specificity needs to be tested.

Sterile Neuroinflammation and Strategies for Therapeutic Intervention

Sterile neuroinflammation is essential for the proper brain development and tissue repair. However, uncontrolled neuroinflammation plays a major role in the pathogenesis of various disease processes. The endogenous intracellular molecules so called damage-associated molecular patterns or alarmins or damage signals that are released by activated or necrotic cells are thought to play a crucial role in initiating an immune response. Sterile inflammatory response that occurs in Alzheimer's disease (AD), Parkinson's disease (PD), stroke, hemorrhage, epilepsy, or traumatic brain injury (TBI) creates a vicious cycle of unrestrained inflammation, driving progressive neurodegeneration. Neuroinflammation is a key mechanism in the progression (e.g., AD and PD) or secondary injury development (e.g., stroke, hemorrhage, stress, and TBI) of multiple brain conditions. Hence, it provides an opportunity for the therapeutic intervention to prevent progressive tissue damage and loss of function. The key for developing anti-neuroinflammatory treatment is to minimize the detrimental and neurotoxic effects of inflammation while promoting the beneficial and neurotropic effects, thereby creating ideal conditions for regeneration and repair. This review outlines how inflammation is involved in the pathogenesis of major nonpathogenic neuroinflammatory conditions and discusses the complex response of glial cells to damage signals. In addition, emerging experimental anti-neuroinflammatory drug treatment strategies are discussed.