Subarachnoid extension of hemorrhage is associated with early seizures in primary intracerebral hemorrhage

Pathophysiology, Diagnosis, Prognosis, and Prevention of Poststroke Epilepsy: Clinical and Research Implications

Poststroke epilepsy (PSE) is associated with higher mortality and poor functional and cognitive outcomes in patients with stroke. With the remarkable development of acute stroke treatment, there is a growing number of survivors with PSE. Although approximately 10% of patients with stroke develop PSE, given the significant burden of stroke worldwide, PSE is a significant problem in stroke survivors. Therefore, the attention of health policymakers and significant funding are required to promote PSE prevention research. The current PSE definition includes unprovoked seizures occurring more than 7 days after stroke onset, given the high recurrence risks of seizures. However, the pathologic cascade of stroke is not uniform, indicating the need for a tissue-based approach rather than a time-based one to distinguish early seizures from late seizures. EEG is a commonly used tool in the diagnostic work-up of PSE. EEG findings during the acute phase of stroke can potentially stratify the risk of subsequent seizures and predict the development of poststroke epileptogenesis. Recent reports suggest that cortical superficial siderosis, which may be involved in epileptogenesis, is a promising marker for PSE. By incorporating such markers, future risk-scoring models could guide treatment strategies, particularly for the primary prophylaxis of PSE. To date, drugs that prevent poststroke epileptogenesis are lacking. The primary challenge involves the substantial cost burden due to the difficulty of reliably enrolling patients who develop PSE. There is, therefore, a critical need to determine reliable biomarkers for PSE. The goal is to be able to use them for trial enrichment and as a surrogate outcome measure for epileptogenesis. Moreover, seizure prophylaxis is essential to prevent functional and cognitive decline in stroke survivors. Further elucidation of factors that contribute to poststroke epileptogenesis is eagerly awaited. Meanwhile, the regimen of antiseizure medications should be based on individual cardiovascular risk, psychosomatic comorbidities, and concomitant medications. This review summarizes the current understanding of poststroke epileptogenesis, its risks, prognostic models, prophylaxis, and strategies for secondary prevention of seizures and suggests strategies to advance research on PSE.

Incidence and risk factors of post-stroke seizures and epilepsy: systematic review and meta-analysis

OBJECTIVE

Due to variability in reports, the aim of this meta-analysis was to evaluate the incidence and risk factors of post-stroke early seizures (ES) and post-stroke epilepsy (PSE).

METHODS

The MEDLINE, EMBASE and Web of Science databases were searched for post-stroke ES/PSE articles published on any date up to November 2020. Post-stroke ES included seizures occurring within 7 days of stroke, and PSE included at least one unprovoked seizure. Using random effects models, the incidence and risk factors of post-stroke ES and PSE were evaluated. The study was retrospectively registered with INPLASY (INPLASY2023100008).

RESULTS

Of 128 included studies in total, the incidence of post-stroke ES was 0.07 (95% confidence interval [CI] 0.05, 0.10) and PSE was 0.10 (95% CI 0.08, 0.13). The rates were higher in children than adults. Risk factors for post-stroke ES included hemorrhagic stroke (odds ratio [OR] 2.14, 95% CI 1.44, 3.18), severe strokes (OR 2.68, 95% CI 1.73, 4.14), cortical involvement (OR 3.09, 95% CI 2.11, 4.51) and hemorrhagic transformation (OR 2.70, 95% CI 1.58, 4.60). Risk factors for PSE included severe strokes (OR 4.92, 95% CI 3.43, 7.06), cortical involvement (OR 3.20, 95% CI 2.13, 4.81), anterior circulation infarcts (OR 3.28, 95% CI 1.34, 8.03), hemorrhagic transformation (OR 2.81, 95% CI 1.25, 6.30) and post-stroke ES (OR 7.24, 95% CI 3.73, 14.06).

CONCLUSION

Understanding the risk factors of post-stroke ES/PSE may identify high-risk individuals who might benefit from prophylactic treatment.

Association of Cortical Superficial Siderosis with Post-Stroke Epilepsy

OBJECTIVE

To assess whether post-stroke epilepsy (PSE) is associated with neuroimaging findings of hemosiderin in a case-control study, and whether the addition of hemosiderin markers improves the risk stratification models of PSE.

METHODS

We performed a post-hoc analysis of the PROgnosis of POST-Stroke Epilepsy study enrolling PSE patients at National Cerebral and Cardiovascular Center, Osaka, Japan, from November 2014 to September 2019. PSE was diagnosed when one unprovoked seizure was experienced >7 days after the index stroke, as proposed by the International League Against Epilepsy. As controls, consecutive acute stroke patients with no history or absence of any late seizure or continuing antiseizure medications at least 3 months after stroke were retrospectively enrolled during the same study period. We examined cortical microbleeds and cortical superficial siderosis (cSS) using gradient-echo T2*-weighted images. A logistic regression model with ridge penalties was tuned using 10-fold cross-validation. We added the item of cSS to the existing models (SeLECT and CAVE) for predicting PSE and evaluated performance of new models.

RESULTS

The study included 180 patients with PSE (67 women; median age 74 years) and 1,183 controls (440 women; median age 74 years). The cSS frequency was higher in PSE than control groups (48.9% vs 5.7%, p < 0.0001). Compared with the existing models, the new models with cSS (SeLECT-S and CAVE-S) demonstrated significantly better predictive performance of PSE (net reclassification improvement 0.63 [p = 0.004] for SeLECT-S and 0.88 [p = 0.001] for CAVE-S at the testing data).

INTERPRETATION

Cortical superficial siderosis was associated with PSE, stratifying stroke survivors at high risk of PSE. ANN NEUROL 2023;93:357-370.

Subarachnoid extension and unfavorable outcomes in patients with supratentorial intracerebral hemorrhage

OBJECTIVE

Our study aimed to investigate the association between the subarachnoid extension of intracranial hemorrhage (SAHE) and clinical outcomes in patients with supratentorial intracerebral hemorrhage (ICH).

METHODS

We analyzed the data from a prospective, multi-center, and registry-based database. Two experienced investigators independently assessed ICH imaging data. We compared baseline characteristics and follow-up outcomes. Multivariable logistic regression analysis was used to evaluate the association between SAHE and poor clinical outcomes. We also performed Kaplan-Meier curves and Cox proportional hazards regression analyses to analyze whether SAHE was relevant to a higher mortality rate.

RESULTS

A total of 931 patients were included in this study (SAHE vs. no SAHE, 121 [13.0%] vs. 810 [87.0%]). Patients with SAHE had more severe neurological deficits, higher scores of the mRS, and more remarkable mortality rates at follow-up (all p values < 0.05). In multivariable-adjusted models, SAHE was independently associated with a higher risk of poor outcomes (adjusted OR [95%CI]: 2.030 [1.142-3.608] at 3 months; 2.348 [1.337-4.123] at 1 year). In addition, SAHE remained an independent association with an increased death rate at 1 year (adjusted HR [95%CI], 1.314[1.057-1.635]). In the subgroup analysis, the correlation between SAHE and prognosis exists in patients with lobar or deep ICH.

CONCLUSIONS

SAHE is independently associated with poor outcomes in patients with supratentorial ICH. It may provide a promising target for developing new predictive tools targeting ICH.

Effects of subarachnoid extension following intracerebral hemorrhage: A systematic review and meta-analysis

BACKGROUND

The effects of subarachnoid extension (SAHE) following intracerebral hemorrhage (ICH) have not yet been fully understood. We conducted a systematic review and meta-analysis of published literature on this topic to better understand the effects of SAHE.

METHODS

PubMed, Embase, and Cochrane databases were thoroughly searched from inception to October 16, 2022 to identify studies that evaluated the association between SAHE and mortality and worse functional outcomes in primary ICH. Crude odds ratios (cOR) and adjusted odds ratios (aOR) with 95% confidence interval (CI) were calculated to compare the endpoints.

RESULTS

Three studies with 3368 participants were eventually included in the analysis. In the short-term follow-up of the primary endpoint, no association was observed between SAHE and mortality (cOR: 0.51, 95% CI: 0.01-28.19; aOR: 2.31, 95% CI: 0.72-7.45). In the long-term follow-up of the primary endpoint, SAHE was associated with a significantly increased mortality of patients with primary ICH (cOR: 3.00, 95% CI: 2.27-3.98); however, only 1 study provided the values of aOR and 95% CI and showed that SAHE was not associated with increased mortality (aOR: 1.14, 95% CI: 0.71-1.83). For the secondary endpoint, the data of only 1 study on major disability (modified Rankin Scale = 3-5) were available, and the results revealed that SAHE increased the probability of major disability, but not after adjusting for baseline hematoma volume.

CONCLUSION

There is insufficient evidence to demonstrate the correlation between SAHE and mortality and worse functional outcomes in primary ICH. The validation of this correlation requires further studies as the potential effect and mechanisms of SAHE remain unclear.

Epileptiform Abnormalities in Acute Ischemic Stroke: Impact on Clinical Management and Outcomes

PURPOSE

Studies examining seizures (Szs) and epileptiform abnormalities (EAs) using continuous EEG in acute ischemic stroke (AIS) are limited. Therefore, we aimed to describe the prevalence of Sz and EA in AIS, its impact on anti-Sz drug management, and association with discharge outcomes.

METHODS

The study included 132 patients with AIS who underwent continuous EEG monitoring >6 hours. Continuous EEG was reviewed for background, Sz and EA (lateralized periodic discharges [LPD], generalized periodic discharges, lateralized rhythmic delta activity, and sporadic epileptiform discharges). Relevant clinical, demographic, and imaging factors were abstracted to identify risk factors for Sz and EA. Outcomes included all-cause mortality, functional outcome at discharge (good outcome as modified Rankin scale of 0-2 and poor outcome as modified Rankin scale of 3-6) and changes to anti-Sz drugs (escalation or de-escalation).

RESULTS

The frequency of Sz was 7.6%, and EA was 37.9%. Patients with Sz or EA were more likely to have cortical involvement (84.6% vs. 67.5% P = 0.028). Among the EAs, the presence of LPD was associated with an increased risk of Sz (25.9% in LPD vs. 2.9% without LPD, P = 0.001). Overall, 21.2% patients had anti-Sz drug changes because of continuous EEG findings, 16.7% escalation and 4.5% de-escalation. The presence of EA or Sz was not associated with in-hospital mortality or discharge functional outcomes.

CONCLUSIONS

Despite the high incidence of EA, the rate of Sz in AIS is relatively lower and is associated with the presence of LPDs. These continuous EEG findings resulted in anti-Sz drug changes in one-fifth of the cohort. Epileptiform abnormality and Sz did not affect mortality or discharge functional outcomes.

Deep Versus Lobar Intraparenchymal Hemorrhage: Seizures, Hyperexcitable Patterns, and Clinical Outcomes

OBJECTIVES

To compare electrographic seizures, hyperexcitable patterns, and clinical outcomes in lobar and deep intraparenchymal hemorrhage. Additionally, to characterize electrographic seizure and hyperexcitable pattern predictors in each group and determine seizure risk with thalamic involvement.

DESIGN

Retrospective cohort study.

SETTING

Tertiary academic medical center.

PATIENTS

Consecutive adult patients with nontraumatic intraparenchymal hemorrhage undergoing continuous electroencephalography at our center between January 2013 and December 2016.

INTERVENTIONS

Not applicable.

MEASUREMENTS AND MAIN RESULTS

Based on head CT closest to the initial continuous electroencephalography session, we classified intraparenchymal hemorrhage as isolated deep (no insular, subarachnoid, subdural extension) or lobar. Hyperexcitable patterns included the following: periodic discharges, spike-wave complexes, any rhythmic delta other than generalized. We used Fisher exact test for categorical and Mann-Whitney U test for continuous variables. Multivariable regression identified predictors of electrographic seizures, hyperexcitable patterns, and poor outcomes (score of 1-2 on Glasgow Outcome Scale) in lobar intraparenchymal hemorrhage. The cohort comprised of 128 patients, 88 lobar, and 40 deep intraparenchymal hemorrhage. Electrographic seizures occurred in 17% of lobar and 5% of deep intraparenchymal hemorrhage (p = 0.09). Hyperexcitable patterns were more frequent in the lobar group (44.3% vs 17.5%; p = 0.005). In multivariable analyses in the lobar group, lateralized rhythmic delta activity predicted electrographic seizures (odds ratio, 6.24; CI, 1.49-26.08; p = 0.012); insular involvement predicted hyperexcitable patterns (odds ratio, 4.88; CI, 1.36-17.57; p = 0.015); coma, temporal lobe involvement, intraparenchymal hemorrhage volume, and electrographic seizures predicted poor outcome. Thalamic involvement did not affect electrographic seizures or hyperexcitable patterns in either group.

CONCLUSIONS

Electrographic seizures are frequent in lobar intraparenchymal hemorrhage, occurring in one in six monitored patients, as opposed to only 5% in isolated deep intraparenchymal hemorrhage not extending to cortex/insula, subarachnoid, or subdural spaces. Patients with lobar intraparenchymal hemorrhage and lateralized rhythmic delta activity were six times as likely to have electrographic seizures, which were associated with 5.47 higher odds of a poor outcome. Coma, temporal lobe involvement, hematoma volume, and electrographic seizures predicted poor outcome in lobar intraparenchymal hemorrhage.

Development and validation of a clinical score to predict late seizures after intracerebral hemorrhage in Chinese

BACKGROUND

Seizures are a frequent complication after intracerebral hemorrhage (ICH). The CAVE score was developed in Europeans to predict late seizures after ICH. Given the higher incidence of ICH in Asians, we aimed to develop and validate a clinical scoring tool for predicting post-ICH late seizures in Chinese.

METHODS

We retrospectively included patients admitted with ICH to a major stroke center in Shandong province, China, in the derivation cohort, who were followed up for occurrence of late seizures (more than seven days after ICH). We applied Cox regression model to identify significant clinical factors which were used to derive a predictive scoring model. The performance of this model was compared with CAVE, and validated in a separate cohort of patients with ICH admitted to another stroke center.

RESULTS

In the derivation cohort (n = 602; median age 65 years; 57 % male；median follow up 24 months), 47 (7.8 %) patients had late seizures during follow up. Four significant risk factors were identified and selected to derive the LANE score (Lobar hemorrhage, Age <65 years, NIHSS score ≥15, Early seizures). The total possible points ranged from 0 to 6, corresponding to positive predictive values of 10.1%-100%, and negative predictive values of 96.8%-92.2%, respectively. The c-statistics of the LANE score in the derivation cohort and validation cohort (n = 521) were 0.83 and 0.78, respectively, while those of the CAVE score were 0.81 and 0.74, respectively.

CONCLUSION

We have developed and validated a clinical scoring tool for predicting late seizures after ICH in Chinese. This tool may be used to identify high risk patients for closer monitoring and clinical trials of therapies to prevent post-ICH epilepsy in the future.

Neuro-Immune Hemostasis: Homeostasis and Diseases in the Central Nervous System

Coagulation and the immune system interact in several physiological and pathological conditions, including tissue repair, host defense, and homeostatic maintenance. This network plays a key role in diseases of the central nervous system (CNS) by involving several cells (CNS resident cells, platelets, endothelium, and leukocytes) and molecular pathways (protease activity, complement factors, platelet granule content). Endothelial damage prompts platelet activation and the coagulation cascade as the first physiological step to support the rescue of damaged tissues, a flawed rescuing system ultimately producing neuroinflammation. Leukocytes, platelets, and endothelial cells are sensitive to the damage and indeed can release or respond to chemokines and cytokines (platelet factor 4, CXCL4, TNF, interleukins), and growth factors (including platelet-derived growth factor, vascular endothelial growth factor, and brain-derived neurotrophic factor) with platelet activation, change in capillary permeability, migration or differentiation of leukocytes. Thrombin, plasmin, activated complement factors and matrix metalloproteinase-1 (MMP-1), furthermore, activate intracellular transduction through complement or protease-activated receptors. Impairment of the neuro-immune hemostasis network induces acute or chronic CNS pathologies related to the neurovascular unit, either directly or by the systemic activation of its main steps. Neurons, glial cells (astrocytes and microglia) and the extracellular matrix play a crucial function in a “tetrapartite” synaptic model. Taking into account the neurovascular unit, in this review we thoroughly analyzed the influence of neuro-immune hemostasis on these five elements acting as a functional unit (“pentapartite” synapse) in the adaptive and maladaptive plasticity and discuss the relevance of these events in inflammatory, cerebrovascular, Alzheimer, neoplastic and psychiatric diseases. Finally, based on the solid reviewed data, we hypothesize a model of neuro-immune hemostatic network based on protein–protein interactions. In addition, we propose that, to better understand and favor the maintenance of adaptive plasticity, it would be useful to construct predictive molecular models, able to enlighten the regulating logic of the complex molecular network, which belongs to different cellular domains. A modeling approach would help to define how nodes of the network interact with basic cellular functions, such as mitochondrial metabolism, autophagy or apoptosis. It is expected that dynamic systems biology models might help to elucidate the fine structure of molecular events generated by blood coagulation and neuro-immune responses in several CNS diseases, thereby opening the way to more effective treatments.

Neuro-Coagulopathy: Blood Coagulation Factors in Central Nervous System Diseases

Blood coagulation factors and other proteins, with modulatory effects or modulated by the coagulation cascade have been reported to affect the pathophysiology of the central nervous system (CNS). The protease-activated receptors (PARs) pathway can be considered the central hub of this regulatory network, mainly through thrombin or activated protein C (aPC). These proteins, in fact, showed peculiar properties, being able to interfere with synaptic homeostasis other than coagulation itself. These specific functions modulate neuronal networks, acting both on resident (neurons, astrocytes, and microglia) as well as circulating immune system cells and the extracellular matrix. The pleiotropy of these effects is produced through different receptors, expressed in various cell types, in a dose- and time-dependent pattern. We reviewed how these pathways may be involved in neurodegenerative diseases (amyotrophic lateral sclerosis, Alzheimer's and Parkinson's diseases), multiple sclerosis, ischemic stroke and post-ischemic epilepsy, CNS cancer, addiction, and mental health. These data open up a new path for the potential therapeutic use of the agonist/antagonist of these proteins in the management of several central nervous system diseases.

Neonatal seizures in preterm newborns: A predictive model for outcome

BACKGROUND

With a reported prevalence of 22.2%, seizures in preterm newborns represent an emergent challenge, because they are often related to adverse outcome. The electroclinical features of preterm infants with neonatal seizures were evaluated in order to predict outcome.

METHODS

From 154 newborns with video-EEG confirmed neonatal seizures admitted to Parma University Hospital between January 1999 and December 2012, we collected 76 preterm newborns with neonatal seizures. Outcome was assessed at least at one year. Student t-test for unpaired data was used to compare means of continuous variables. We applied the χ(2) test to compare nominal data between preterm newborns with favorable versus adverse outcome, and between those with seizures versus those with status epilepticus. Then we determined the independent risk factors for adverse outcome with multivariate logistic regression analysis.

RESULTS

Birth weight, Apgar at 1st minute, neurologic examination, EEG, US brain scans and the presence of neonatal status epilepticus were different between preterm newborns with favorable and adverse outcome (p ≤ .049). Furthermore, birth weight, seizure onset, neurologic examination and EEG were different between the group with or without status (p ≤ .031). None of the infants with status epilepticus had a favorable outcome compared to 22.3% of those with neonatal seizures (p = .004). We also identified a predictive model that correctly classified outcome in 85.5% of subjects, with a high sensitivity for adverse outcome (>91.5%).

CONCLUSION

The presence of neonatal seizures in preterm newborns is highly related to an adverse outcome that can be predicted since the first days of life.

Early-Onset Convulsive Seizures Induced by Brain Hypoxia-Ischemia in Aging Mice: Effects of Anticonvulsive Treatments

Aging is associated with an increased risk of seizures/epilepsy. Stroke (ischemic or hemorrhagic) and cardiac arrest related brain injury are two major causative factors for seizure development in this patient population. With either etiology, seizures are a poor prognostic factor. In spite of this, the underlying pathophysiology of seizure development is not well understood. In addition, a standardized treatment regimen with anticonvulsants and outcome assessments following treatment has yet to be established for these post-ischemic seizures. Previous studies have modeled post-ischemic seizures in adult rodents, but similar studies in aging/aged animals, a group that mirrors a higher risk elderly population, remain sparse. Our study therefore aimed to investigate early-onset seizures in aging animals using a hypoxia-ischemia (HI) model. Male C57 black mice 18-20-month-old underwent a unilateral occlusion of the common carotid artery followed by a systemic hypoxic episode (8% O2 for 30 min). Early-onset seizures were detected using combined behavioral and electroencephalographic (EEG) monitoring. Brain injury was assessed histologically at different times post HI. Convulsive seizures were observed in 65% of aging mice post-HI but not in control aging mice following either sham surgery or hypoxia alone. These seizures typically occurred within hours of HI and behaviorally consisted of jumping, fast running, barrel-rolling, and/or falling (loss of the righting reflex) with limb spasms. No evident discharges during any convulsive seizures were seen on cortical-hippocampal EEG recordings. Seizure development was closely associated with acute mortality and severe brain injury on brain histological analysis. Intra-peritoneal injections of lorazepam and fosphenytoin suppressed seizures and improved survival but only when applied prior to seizure onset and not after. These findings together suggest that seizures are a major contributing factor to acute mortality in aging mice following severe brain ischemia and that early anticonvulsive treatment may prevent seizure genesis and improve overall outcomes.

Modeling early-onset post-ischemic seizures in aging mice

Stroke is the leading cause of seizures and epilepsy in the aged population, with post-stroke seizures being a poor prognostic factor. The pathological processes underlying post-stroke seizures are not well understood and studies of these seizures in aging/aged animals remain scarce. Therefore, our primary objective was to model post-stroke seizures in aging mice (C57 black strain, 16-20 months-old), with a focus on early-onset, convulsive seizures that occur within 24-hours of brain ischemia. We utilized a middle cerebral artery occlusion model and examined seizure activity and brain injury using combined behavioral and electroencephalographic monitoring and histological assessments. Aging mice exhibited vigorous convulsive seizures within hours of the middle cerebral artery occlusion. These seizures manifested with jumping, rapid running, barrel-rolling and/or falling all in the absence of hippocampal-cortical electrographic discharges. Seizure development was closely associated with severe brain injury and acute mortality. Anticonvulsive treatments after seizure occurrence offered temporary seizure control but failed to improve animal survival. A separate cohort of adult mice (6-8 months-old) exhibited analogous early-onset convulsive seizures following the middle cerebral artery occlusion but had better survival outcomes following anticonvulsive treatment. Collectively, our data suggest that early-onset convulsive seizures are a result of severe brain ischemia in aging animals.