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.

Current and Emerging Endovascular and Neurocritical Care Management Strategies in Large-Core Ischemic Stroke

The volume of infarcted tissue in patients with ischemic stroke is consistently associated with increased morbidity and mortality. Initial studies of endovascular thrombectomy for large-vessel occlusion excluded patients with established large-core infarcts, even when large volumes of salvageable brain tissue were present, due to the high risk of hemorrhagic transformation and reperfusion injury. However, recent retrospective and prospective studies have shown improved outcomes with endovascular thrombectomy, and several clinical trials were recently published to evaluate the efficacy of endovascular management of patients presenting with large-core infarcts. With or without thrombectomy, patients with large-core infarcts remain at high risk of in-hospital complications such as hemorrhagic transformation, malignant cerebral edema, seizures, and others. Expert neurocritical care management is necessary to optimize blood pressure control, mitigate secondary brain injury, manage cerebral edema and elevated intracranial pressure, and implement various neuroprotective measures. Herein, we present an overview of the current and emerging evidence pertaining to endovascular treatment for large-core infarcts, recent advances in neurocritical care strategies, and their impact on optimizing patient outcomes.

Risk of poststroke epilepsy after reperfusion therapies: A national cohort study

BACKGROUND AND PURPOSE

The risk of poststroke epilepsy (PSE) after endovascular treatment (EVT) is not well characterized. In this nationwide study, we assessed the risk of PSE after EVT and identified associated predictors.

METHODS

We included all individuals (n = 3319) treated with EVT (±intravenous thrombolysis [IVT]) between 2015 and 2019 in the Swedish National Quality Register for EVT. Two control groups were identified from the Swedish Stroke Register: the first treated with IVT alone (n = 3132) and the second with no treatment (n = 3184), both matched for age, sex, stroke severity, and time of stroke.

RESULTS

PSE developed in 7.9% (n = 410). The survival-adjusted 2-year risk was 6.5% (95% confidence interval [CI] = 5.28-7.70) after EVT, 10.0% (95% CI = 8.25-11.75) after IVT, and 12.3% after no revascularization (95% CI = 10.33-14.25). The hazard ratio (HR) of PSE after EVT was almost half compared to no treatment (HR = 0.51, 95% CI = 0.41-0.64). The risk of PSE after EVT was lower compared to no treatment in a multivariable Cox model that adjusted for age, sex, hemicraniectomy, and stroke severity (HR = 0.76, 95% CI = 0.60-0.96). Multivariable predictors of PSE after EVT were large infarction on computed tomography Day 1, high posttreatment National Institutes of Health Stroke Scale score, and need of assistance 3 months after stroke. IVT before EVT was associated with a lower risk of PSE (HR = 0.66, 95% CI = 0.46-0.94).

CONCLUSIONS

This nationwide study identified a reduced risk of PSE after EVT. Markers of severe infarction after EVT were associated with PSE, whereas IVT given before EVT was protective.

Frequency of epileptic seizures in patients undergoing decompressive craniectomy after ischemic stroke

BACKGROUND

Decompressive surgery has proven to be lifesaving in patients with a malignant anterior circulation ischemic stroke. Recently, some studies have shown a high frequency of epileptic seizures in patients undergoing this procedure. However, the quantification of this risk and its associated factors have not been extensively investigated.

OBJECTIVE

To determine the frequency of epileptic seizures and epilepsy in patients with an anterior circulation ischemic stroke admitted to our Stroke Unit from January 2006 to March 2019 that have been submitted to craniectomy and to study their associated demographic, clinical, imagiological and neurophysiological features.

METHODS

Retrospective observational study of 56 consecutive patients with an anterior circulation ischemic stroke that have undergone craniectomy. The frequency of seizures was both clinically and neurophysiologically assessed after reviewing clinical records, discharge or death reports and all EEGs performed during the hospital admission. Bivariate analysis was used to compare patients with and without seizures.

RESULTS

Sixteen patients (28,6%) had epileptic seizures. Bivariate analysis showed an association between the occurrence of unprovoked seizures and the median ASPECTS from the first CT performed.

CONCLUSIONS

In this study, the frequency of epileptic seizures after a malignant stroke submitted to craniectomy was high, albeit lower than that reported in previous studies. The size of infarction at hospital admission appears to be a risk factor for the occurrence of epilepsy in this group of patients.

Hospital Revisits for Post-Ischemic Stroke Epilepsy after Acute Stroke Interventions

OBJECTIVES

Improvements in acute stroke care have led to an increase in ischemic stroke survivors, who are at risk for development of post-ischemic stroke epilepsy (PISE). The impact of therapies such as thrombectomy and thrombolysis on risk of hospital revisits for PISE is unclear. We utilized administrative data to investigate the association between stroke treatment and PISE-related visits.

MATERIALS AND METHODS

Using claims data from California, New York, and Florida, we performed a retrospective analysis of adult survivors of acute ischemic strokes. Patients with history of epilepsy, trauma, infections, or tumors were excluded. Included patients were followed for a primary outcome of revisits for seizures or epilepsy. Cox proportional hazards regression was used to identify covariates associated with PISE.

RESULTS

In 595,545 included patients (median age 74 [IQR 21], 52% female), the 6-year cumulative rate of PISE-related revisit was 2.20% (95% CI 2.16-2.24). In multivariable models adjusting for demographics, comorbidities, and indicators of stroke severity, IV-tPA (HR 1.42, 95% CI 1.31-1.54, p<0.001) but not MT (HR 1.62, 95% CI 0.90-1.50, p=0.2) was associated with PISE-related revisit. Patients who underwent decompressive craniectomy experienced a 2-fold increase in odds for returning with PISE (HR 2.35, 95% CI 1.69-3.26, p<0.001). In-hospital seizures (HR 4.06, 95% CI 3.76-4.39, p<0.001) also elevated risk for PISE.

SIGNIFICANCE

We demonstrate that ischemic stroke survivors who received IV-tPA, underwent decompressive craniectomy, or experienced acute seizures were at increased risk PISE-related revisit. Close attention should be paid to these patients with increased potential for long-term development of and re-hospitalization for PISE.

Effect of Reperfusion Therapies on Incidence of Early Post-Stroke Seizures

Objective: This study aimed to determine the effect of reperfusion therapies on the occurrence of early post-stroke seizures (PSS) in patients with acute ischemic stroke (AIS). Background: Reperfusion therapies are paramount to the treatment of stroke in the acute phase. However, their effect on the incidence of early seizures after an AIS remains unclear. Design and Methods: The stroke database at Hamad Medical Corporation was used to identify all patients who received reperfusion therapies for AIS from 2016 to 2019. They were matched with patients of similar diagnosis, gender, age, and stroke severity as measured by National Institutes of Health Stroke Scale (NIHSS) who did not receive such treatment. The rates of early PSS were calculated for each group. Results: The results showed that 508 patients received reperfusion therapies (342 had IV thrombolysis only, 70 had thrombectomies only, and 96 had received both), compared with 501 matched patients receiving standard stroke unit care. Patients who received reperfusion therapies were similar to their matched controls for mean admission NIHSS score (9.87 vs. 9.79; p = 0.831), mean age (53.3 vs. 53.2 years; p = 0.849), and gender distribution (85 vs. 86% men; p = 0.655). The group receiving reperfusion therapies was found to have increased stroke cortical involvement (62 vs. 49.3%, p < 0.001) and hemorrhagic transformation rates (33.5 vs. 18.6%, p < 0.001) compared with the control group. The rate of early PSS was significantly lower in patients who received reperfusion therapies compared with those who did not (3.1 vs. 5.8%, respectively; p = 0.042). When we excluded seizures occurring at stroke onset prior to any potential treatment implementation, the difference in early PSS rates between the two groups was no longer significant (2.6 vs. 3.9%, respectively; p = 0.251). There was no significant difference in early PSS rate based on the type of reperfusion therapy either (3.2% with thrombolysis, 2.9% with thrombectomy, and 3.1% for the combined treatment, p = 0.309). Conclusions: Treatment of AIS with either thrombectomy, thrombolysis, or both does not increase the risk of early PSS.

Seizures and epilepsy in patients with ischaemic stroke

BACKGROUND

With the increased efficacy of stroke treatments, diagnosis and specific treatment needs of patients with post-stroke seizures (PSS) and post-stroke epilepsy have become increasingly important. PSS can complicate the diagnosis of a stroke and the treatment of stroke patients, and can worsen post-stroke morbidity. This narrative review considers current treatment guidelines, the specifics of antiseizure treatment in stroke patients as well as the state-of-the-art in clinical and imaging research of post-stroke epilepsy. Treatment of PSS needs to consider indications for antiseizure medication treatment as well as individual clinical and social factors. Furthermore, potential interactions between stroke and antiseizure treatments must be carefully considered. The relationship between acute recanalizing stroke therapy (intravenous thrombolysis and mechanical thrombectomy) and the emergence of PSS is currently the subject of an intensive discussion. In the subacute and chronic post-stroke phases, important specific interactions between necessary antiseizure and stroke treatments (anticoagulation, cardiac medication) need to be considered. Among all forms of prevention, primary prevention is currently the most intensively researched. This includes specifically the repurposing of drugs that were not originally developed for antiseizure properties, such as statins. PSS are presently the subject of extensive basic clinical research. Of specific interest are the role of post-stroke excitotoxicity and blood-brain barrier disruption for the emergence of PSS in the acute symptomatic as well as late (> 1 week after the stroke) periods. Current magnetic resonance imaging research focussing on glutamate excitotoxicity as well as diffusion-based estimation of blood-brain barrier integrity aim to elucidate the pathophysiology of seizures after stroke and the principles of epileptogenesis in structural epilepsy in general. These approaches may also reveal new imaging-based biomarkers for prediction of PSS and post-stroke epilepsy.

CONCLUSION

PSS require the performance of individual risk assessments, accounting for the potential effectiveness and side effects of antiseizure therapy. The use of intravenous thrombolysis and mechanical thrombectomy is not associated with an increased risk of PSS. Advances in stroke imaging may reveal biomarkers for PSS.

Impact of drug treatment and drug interactions in post-stroke epilepsy

Stroke is a huge burden on our society and this is expected to grow in the future due to the aging population and the associated co-morbidities. The improvement of acute stroke care has increased the survival rate of stroke patients, and many patients are left with permanent disability, which makes stroke the main cause of adult disability. Unfortunately, many patients face other severe complications such as post-stroke seizures and epilepsy. Acute seizures (ASS) occur within 1 week after the stroke while later occurring unprovoked seizures are diagnosed as post-stroke epilepsy (PSE). Both are associated with a poor prognosis of a functional recovery. The underlying neurobiological mechanisms are complex and poorly understood. There are no universal guidelines on the management of PSE. There is increasing evidence for several risk factors for ASS/PSE, however, the impacts of recanalization, drugs used for secondary prevention of stroke, treatment of stroke co-morbidities and antiseizure medication are currently poorly understood. This review focuses on the common medications that stroke patients are prescribed and potential drug interactions possibly complicating the management of ASS/PSE.

Seizures after Ischemic Stroke: A Matched Multicenter Study

Objective

The purpose of this study was to identify risk factors for acute symptomatic seizures and post‐stroke epilepsy after acute ischemic stroke and evaluate the effects of reperfusion treatment.

Methods

We assessed the risk factors for post‐stroke seizures using logistic or Cox regression in a multicenter study, including adults from 8 European referral centers with neuroimaging‐confirmed ischemic stroke. We compared the risk of post‐stroke seizures between participants with or without reperfusion treatment following propensity score matching to reduce confounding due to treatment selection.

Results

In the overall cohort of 4,229 participants (mean age 71 years, 57% men), a higher risk of acute symptomatic seizures was observed in those with more severe strokes, infarcts located in the posterior cerebral artery territory, and strokes caused by large‐artery atherosclerosis. Strokes caused by small‐vessel occlusion carried a small risk of acute symptomatic seizures. 6% developed post‐stroke epilepsy. Risk factors for post‐stroke epilepsy were acute symptomatic seizures, more severe strokes, infarcts involving the cerebral cortex, and strokes caused by large‐artery atherosclerosis. Electroencephalography findings within 7 days of stroke onset were not independently associated with the risk of post‐stroke epilepsy. There was no association between reperfusion treatments in general or only intravenous thrombolysis or mechanical thrombectomy with the time to post‐stroke epilepsy or the risk of acute symptomatic seizures.

Interpretation

Post‐stroke seizures are related to stroke severity, etiology, and location, whereas an early electroencephalogram was not predictive of epilepsy. We did not find an association of reperfusion treatment with risks of acute symptomatic seizures or post‐stroke epilepsy. ANN NEUROL 2021;90:808–820

Multifactorial Predictors of Late Epileptic Seizures Related to Stroke: Evaluation of the Current Possibilities of Stratification Based on Existing Prognostic Models-A Comprehensive Review

Background: Epilepsy associated with strokes is a significant clinical and public health problem and has a negative impact on prognosis and clinical outcome. A late epileptic seizure occurring seven days after stroke is actually equated with poststroke epilepsy due to the high risk of recurrence. Predictive models evaluated in the acute phase of stroke would allow for the stratification and early selection of patients at higher risk of developing late seizures. Methods: The most relevant papers in this field were reviewed to establish multifactorial predictors of late seizures and attempt to standardize and unify them into a common prognostic model. Results: Clinical and radiological factors have become the most valuable and reproducible predictors in many reports, while data on electroencephalographic, genetic, and blood biomarkers were limited. The existing prognostic models, CAVE and SeLECT, based on relevant, readily available, and routinely assessed predictors, should be validated and improved in multicenter studies for widespread use in stroke units. Conclusions: Due to contradictory reports, a common and reliable model covering all factors is currently not available. Further research might refine forecasting models by incorporating advanced radiological neuroimaging or quantitative electroencephalographic analysis.

Intravenous thrombolysis or mechanical thrombectomy do not increase risk of acute symptomatic seizures in patients with ischemic stroke

Recent data have suggested that performing recanalizing therapies in ischemic stroke might lead to an increased risk of acute symptomatic seizures. This applies to both intravenous thrombolysis and mechanical thrombectomy. We therefore determined the frequency of acute symptomatic seizures attributable to these two recanalization therapies using a large, population-based stroke registry in Central Europe. We performed two matched 1:1 case–control analyses. In both analyses, patients were matched for age, stroke severity on admission and pre-stroke functional status. The first analysis compared patients treated with intravenous thrombolysis to a non-recanalization control group. To isolate the effect of mechanical thrombectomy, we compared patients with both mechanical thrombectomy and intravenous thrombolysis to those with only intravenous thrombolysis treatment in a second analysis. From 135,117 patients in the database, 13,356 patients treated with only intravenous thrombolysis, and 1013 patients treated with both intravenous thrombolysis and mechanical thrombectomy were each matched to an equivalent number of controls. Patients with intravenous thrombolysis did not suffer from clinically apparent acute symptomatic seizures significantly more often than non-recanalized patients (treatment = 199; 1.5% vs. control = 237; 1.8%, p = 0.07). Mechanical thrombectomy in addition to intravenous thrombolysis also was not associated with an increased risk of acute symptomatic seizures, as the same number of patients suffered from seizures in the treatment and control group (both n = 17; 1.7%, p = 1). In a large population-based stroke registry, the frequency of clinically apparent acute symptomatic seizures was not increased in patients who received either intravenous thrombolysis alone or in conjunction with mechanical thrombectomy.

Blood biomarkers predictive of epilepsy after an acute stroke event

OBJECTIVE

Blood biomarkers have not been widely investigated in poststroke epilepsy. In this study, we aimed to describe clinical factors and biomarkers present during acute stroke and analyze their association with the development of epilepsy at long term.

METHODS

A panel of 14 blood biomarkers was evaluated in patients with ischemic and hemorrhagic stroke. Biomarkers were normalized and standardized using Z-scores. Stroke and epilepsy-related variables were also assessed: stroke severity, determined by National Institutes of Health Stroke Scale (NIHSS) score, stroke type and cause, time from stroke to onset of late seizures, and type of seizure. Multiple Cox regression models were used to identify clinical variables and biomarkers independently associated with epilepsy.

RESULTS

From a cohort of 1115 patients, 895 patients were included. Mean ± standard deviation (SD) age was 72.0 ± 13.1 years, and 57.8% of patients were men. Fifty-one patients (5.7%) developed late seizures, with a median time to onset of 232 days (interquartile range [IQR] 86-491). NIHSS score ≥8 (P < .001, hazard ratio [HR] 4.013, 95% confidence interval [CI] 2.123-7.586) and a history of early onset seizures (P < .001, HR 4.038, 95% CI 1.802-9.045) were factors independently associated with a risk of developing epilepsy. Independent blood biomarkers predictive of epilepsy were high endostatin levels >1.203 (P = .046, HR 4.300, 95% CI 1.028-17.996) and low levels of heat shock 70 kDa protein-8 (Hsc70) <2.496 (P = .006, HR 3.795, 95% CI 1.476-9.760) and S100B <1.364 (P = .001, HR 2.955, 95% CI 1.534-5.491). The risk of epilepsy when these biomarkers were combined increased to 17%. The area under the receiver-operating characteristic (ROC) curve of the predictive model was stronger when clinical variables were combined with blood biomarkers (74.3%, 95% CI 65.2%-83.3%) than when they were used alone (68.9%, 95% CI 60.3%-77.6%).

SIGNIFICANCE

Downregulated S100B and Hsc70 and upregulated endostatin may assist in prediction of poststroke epilepsy and may provide additional information to clinical risk factors. In addition, these data are hypothesis-generating for the epileptogenic process.

Incidence and Association of Reperfusion Therapies With Poststroke Seizures: A Systematic Review and Meta-Analysis

BACKGROUND AND PURPOSE

We performed a systematic review and meta-analysis to assess the incidence and risk of seizures following acute stroke reperfusion therapy (intravenous thrombolysis [IVT] with r-tPA [recombinant tissue-type plasminogen activator], mechanical thrombectomy or both).

METHODS

We searched major databases (MEDLINE, SCOPUS, and Cochrane Library) for articles published between 1995 and October 28, 2019. The primary outcome was the overall and treatment specific pooled incidence of poststroke seizures (PSS) following acute reperfusion therapy. We also computed the pooled incidence of early poststroke seizures and late poststroke seizures separately for all studies. We derived the risk of PSS associated with IVT in the pooled cohort of patients who received only IVT. The small number of studies (<3) that reported on the risk of PSS associated with mechanical thrombectomy alone or in combination with IVT did not allow us to compute an estimate of the risk of seizures associated with this therapy.

RESULTS

We identified 13 753 patients with stroke, of which 592 had seizures. The pooled incidence of PSS was 5.9 % (95% CI, 4.2%-8.2%). PSS incidence rates among patients with stroke treated with IVT, mechanical thrombectomy, and both were respectively 6.1% (95% CI, 3.6%-10.2%), 5.9% (95% CI, 4.1%-8.4%), and 5.8 % (95% CI, 3.0%-10.9%). The incidence of late PSS was 6.7% (95% CI, 4.01%-11.02%) and that of early PSS was 3.14% (95% CI, 2.05%-4.76%). The pooled odds ratio for the association between IVT and PSS was 1.24 (95% CI, 0.75-2.05).

CONCLUSIONS

The findings of this meta-analysis suggest that about one in 15 ischemic stroke patients treated with IVT, mechanical thrombectomy, or both develop seizures independently of the specific reperfusion treatment that they received.

Early poststroke seizures following thrombolysis and/or thrombectomy for acute stroke: Clinical and stroke characteristics

In this retrospective study, we explored the clinical and stroke characteristics of patients treated with thrombolysis and/or mechanical thrombectomy for an acute stroke and experiencing early poststroke seizures within 7 days of the cerebrovascular accident. Patients with prior epilepsy, primary intracerebral hemorrhage or transient ischemic attacks, or taking antiepileptic drugs were excluded. We retrospectively identified 32 patients admitted between 2010 and 2016 (mean age 75 years; range: 49-90; 14 females and 18 males). A cortical stroke was found in more than 70% of patients. Most epileptic seizures were focal aware (46.7%) or generalized convulsive (43.3%). The median time between stroke onset and seizure occurrence was 2 days; in 75.9% of the cases, seizures occurred within the first 3 days. This retrospective case series is the largest published so far providing details on clinical features of patients with early poststroke seizures following different reperfusion therapies, not only restricted to intravenous (i.v.) thrombolysis. Early poststroke seizures following reperfusion therapies are associated with cortical stroke involvement, are usually focal without impairment of awareness or generalized convulsive, and occur mostly within the first 3 days. Further studies are needed to clarify whether the low prevalence of focal impaired awareness seizures (and nonconvulsive seizures/status) is real or reflects the failure to recognize and correctly diagnose this seizure type in the acute poststroke period (risk of underascertainment due to the lack of systematic video-electroencephalogram (EEG) recording in patients with stroke and difficulties in recognizing these seizures). This article is part of the Special Issue "Seizures & Stroke".

Acute symptomatic seizures and epilepsy after mechanical thrombectomy

PURPOSE

The purpose of this study was to assess the incidence of acute symptomatic seizures and poststroke epilepsy (PSE) in a well-characterized cohort of patients treated with mechanical thrombectomy. In addition, we aimed to describe the dynamics of blood markers of brain injury in patients that developed PSE.

METHODS

Participants of the prospective AnStroke Trial of anesthesia method during mechanical thrombectomy were included and acute symptomatic seizures and PSE ascertained by medical records review. Blood markers neurofilament light (NFL), tau, glial fibrillary acidic protein (GFAP), S100 calcium-binding protein B (S100B), and neuron-specific enolase (NSE) were assessed.

RESULTS

A total of 90 patients with acute anterior ischemic stroke were included. Median National Institutes of Health Stroke Scale (NIHSS) at admission to hospital was 18 (IQR 15-22). Recanalization was achieved in 90%. No patients had epilepsy prior to the ischemic stroke. Four patients (4.4%) had acute symptomatic seizures and four patients (4.4%) developed PSE during the follow-up time (to death or last medical records review) of 0-4.5 years (median follow-up 1070 days IQR 777-1306), resulting in a two-year estimated PSE risk of 5.3% (95%CI: 0.2-10.4%). Blood markers of brain injury (NFL, tau, GFAP, S100B, and NSE) were generally above the cohort median in patients that developed PSE.

CONCLUSIONS

The incidence of PSE after mechanical thrombectomy was low in our cohort. All blood biomarkers displayed interesting sensitivity and specificity. However, the number of PSE cases was small and more studies are needed on risk factors for PSE after mechanical thrombectomy. The potential of blood markers of brain injury markers to contribute to assessment of PSE risk should be explored further. This article is part of the Special Issue "Seizures & Stroke".

Reperfusion therapies and poststroke seizures

Seizures are not only a frequent complication of stroke but have been associated with an unfavorable functional and vital outcome of patients who have had stroke. Facing a new paradigm of acute standard stroke care, acute symptomatic seizures in this clinical setting deserve to be rethought. Reperfusion therapies, the gold standard treatment for acute ischemic stroke, improve long-term survival and outcome of patients who have had stroke and have been associated both with clinical seizures and the occurrence of epileptiform activity in the electroencephalogram (EEG). This narrative review describes the different physiopathological mechanisms underlying the possible association between reperfusion therapies and seizures, both acute symptomatic seizures and unprovoked seizures, and the current evidence regarding the risk of poststroke seizures in treated patients. It also identifies the gaps in our knowledge to foster future studies in this field. By different mechanisms, reperfusions therapies may have opposing effects on the risk of poststroke seizures. There is a need for a better definition of the specific physiopathology of seizures in clinical practice, as many factors can be recognized. Additionally, most of the current clinical evidence refers to acute symptomatic seizures and not to unprovoked seizures or poststroke epilepsy, and our analysis does not support the existence of a strong association between thrombolysis and poststroke seizures. So far, the impact of reperfusion therapies on the frequency of poststroke seizures is unclear. To study this effect, many clinical challenges must be overcome, including a better and clear operational definition of seizures and stroke characteristics, the standard of stroke and epilepsy care and EEG monitoring, and the degree of reperfusion success. Prospective, high quality, larger, and longer follow-up multicentric studies are urgently needed. Additionally, stroke registries can also prove useful in better elucidate whether there is an association between reperfusion therapies and seizures. This article is part of the Special Issue "Seizures & Stroke".

Incidence of early poststroke seizures during reperfusion therapies in patients with acute ischemic stroke: An observational prospective study: (TESI study: "Trombolisi/Trombectomia e crisi Epilettiche precoci nello Stroke Ischemico")

INTRODUCTION

The aim of this study was to prospectively investigate the occurrence of early poststroke seizures (within 7 days of stroke) in patients undergoing reperfusion therapies (intravenous rtPA [recombinant tissue plasminogen activator] and/or endovascular thrombectomy) in comparison to those not undergoing these procedures.

METHODS

Patients aged ≥18 years with acute ischemic stroke admitted in five Italian centers were prospectively recruited. Clinical data, details on stroke type and etiology, stroke treatment, and radiological data were collected. The frequency of early poststroke seizures was assessed, and predictive factors for their occurrence were evaluated.

RESULTS

Five hundred and sixteen patients (262 in the reperfusion therapies group) were included. Stroke severity on admission and at discharge was higher among patients undergoing reperfusion therapies. Ten patients (3.8%) undergoing reperfusion therapies and 6 (2.3%) of those not receiving these treatments experienced early poststroke seizures (p = 0.45). There were no differences in any of the baseline characteristics between patients experiencing and those not experiencing early seizures.

CONCLUSION

The incidence of early poststroke seizures was overall rare, and no significant differences emerged between patients receiving and those not receiving reperfusion therapies. This article is part of the Special Issue "Seizures and Stroke".

Intravenous thrombolysis with tPA and cortical involvement increase the risk of early poststroke seizures: Results of a case-control study

The aim of this study was to identify the risk factors for early poststroke seizures (PSS) in patients with acute ischemic stroke. We undertook a case-control study at a single stroke center. Patients with seizure occurring during the first 7 days following ischemic stroke admitted between 2010 and 2016 were retrospectively identified and matched with controls (patients with stroke without early PSS) for age and sex. We included 79 cases and 158 controls. Blood sugar levels on admission, stroke localization, National Institutes of Health Stroke Scale (NIHSS) and Rankin score, and intravenous (i.v.) thrombolysis with recombinant tissue plasminogen activator (rtPA) were statistically associated with early PSS in univariate analysis. Multiple logistic regression after forward and backward variable selection identified cortical stroke localization (odds ratio (OR): 2.49; 95% confidence intervals (CI): 1.35 to 4.59; p = 0.003) and i.v. thrombolysis (OR: 2.26; 95% CI: 1.16 to 4.43; p = 0.008) as variables independently associated with early PSS. Cortical involvement and i.v. thrombolysis are independent risk factors associated with the occurrence of early PSS. This association is not explained by age or sex, concomitant drugs, diabetes or alcoholism, sodium and cholesterol levels, blood pressure on admission, stroke etiology or severity, and hemorrhage following i.v. thrombolysis. Further studies are required to fully elucidate the association between different reperfusion therapies and early PSS. This article is part of the Special Issue "Seizures & Stroke".

Younger age at stroke onset but not thrombolytic treatment predicts poststroke epilepsy: An updated meta-analysis

AIMS

Stroke is the most commonly identified cause of late-onset epilepsy. Risk factors for poststroke epilepsy (PSE) are partially elucidated, and many studies have been performed in recent years. We aimed to update our previous systematic review and meta-analysis on risk factors for PSE.

METHODS

PubMed, Google Scholar, and Scopus databases were searched. Articles published in English (1987-2019) were included. Odds ratios (OR) and mean values were calculated for examined variables.

RESULTS

Thirty studies with different designs were included, enrolling 26,045 patients who experienced stroke, of whom 1800 had PSE, corresponding to a prevalence of 7%. Cortical lesions (OR: 3.58, 95% confidence interval (CI): 2.35-5.46, p < 0.001), hemorrhagic component (OR: 2.47, 95% CI: 1.68-3.64, p < 0.001), early seizures (ES) (OR: 4.88, 95% CI: 3.08-7.72, p < 0.001), and younger age at stroke onset (difference in means: 2.97 years, 95% CI: 0.78 to 5.16, p = 0.008) favor PSE. Sex and acute treatment with recombinant tissue plasminogen activator (rtPA) do not predict the occurrence of PSE.

CONCLUSION

Despite limitations due to the uneven quality and design of the studies, the present meta-analysis confirms that cortical involvement, hemorrhagic component, and ES are associated with a higher risk of PSE. In this update, younger age at stroke onset but not thrombolytic treatment seems to increase the risk for PSE. This article is part of the Special Issue "Seizures & Stroke".

Modeling poststroke epilepsy and preclinical development of drugs for poststroke epilepsy

Stroke is a severe clinical issue for global public health, representing the third leading cause of death and a major cause of disability in developed countries. Progresses in the pharmacological treatment of the acute stroke have given rise to a significant decrease in its mortality rate. However, as a result, there has been an increasing number of stroke survivors living with disability worldwide. Poststroke epilepsy (PSE) is a common clinical complication following stroke. Seizures can arise in close temporal association with stroke damage and/or after a variably longer interval. Overall, PSE have a good prognosis; in fact, its responding rate to antiepileptic drugs (AEDs) is higher than other types of epilepsy. However, regarding pharmacological treatment, some issues are still unresolved. To this aim, a deeper understanding of mechanisms underlying the transformation of infarcted tissue into an epileptic focus or better from a nonepileptic brain to an epileptic brain is also mandatory for PSE. However, studying epileptogenesis in patients with PSE clearly has several limitations and difficulties; therefore, modeling PSE is crucial. Until now, different experimental models have been used to study the etiopathology of cerebrovascular stroke with or without infarction, but few studies focused on poststroke epileptogenesis and PSE. In this review, we show a brief overview on the features emerging from preclinical research into experimental PSE, which could affect the discovery of biomarkers and therapy strategies for poststroke epileptogenesis. This article is part of the Special Issue "Seizures & Stroke".

Incidence, Implications, and Management of Seizures Following Ischemic and Hemorrhagic Stroke

PURPOSE OF REVIEW

In this review, we summarize the recent literature regarding the incidence and treatment of seizures arising after ischemic and hemorrhagic strokes. Additionally, we identify open questions in guidelines and standard clinical care to aid future studies aiming to improve management of seizures in post-stroke patients.

RECENT FINDINGS

Studies demonstrate an increasing prevalence of seizures following strokes, probably a consequence of advances in post-stroke management and expanding use of continuous EEG monitoring. Post-stroke seizures are associated with longer hospitalization and increased mortality; therefore, prevention and timely treatment of seizures are important. The standard of care is to treat recurrent seizures with anti-epileptic drugs (AEDs) regardless of the etiology. However, there are no established guidelines currently for prophylactic use of AEDs following a stroke. The prevalence of post-stroke seizures is increasing. Further studies are needed to determine the risk factors for recurrent seizures and epilepsy after strokes and optimal treatment strategies.

Prediction of late seizures after ischaemic stroke with a novel prognostic model (the SeLECT score): a multivariable prediction model development and validation study

BACKGROUND

Stroke is one of the leading causes of acquired epilepsy in adults. An instrument to predict whether people are at high risk of developing post-stroke seizures is not available. We aimed to develop and validate a prognostic model of late (>7 days) seizures after ischaemic stroke.

METHODS

In this multivariable prediction model development and validation study, we developed the SeLECT score based on five clinical predictors in 1200 participants who had an ischaemic stroke in Switzerland using backward elimination of a multivariable Cox proportional hazards model. We externally validated this score in 1169 participants from three independent international cohorts in Austria, Germany, and Italy, and assessed its performance with the concordance statistic and calibration plots.

FINDINGS

Data were complete for 99·2% of the predictors (99·2% for Switzerland, 100% for Austria, 97% for Germany, and 99·7% for Italy) and 100% of the outcome parameters. Overall, the risk of late seizures was 4% (95% CI 4-5) 1 year after stroke and 8% (6-9) 5 years after stroke. The final model included five variables and was named SeLECT on the basis of the first letters of the included parameters (severity of stroke, large-artery atherosclerotic aetiology, early seizures, cortical involvement, and territory of middle cerebral artery involvement). The lowest SeLECT value (0 points) was associated with a 0·7% (95% CI 0·4-1·0) risk of late seizures within 1 year after stroke (1·3% [95% CI 0·7-1·8] within 5 years), whereas the highest value (9 points) predicted a 63% (42-77) risk of late seizures within 1 year (83% [62-93] within 5 years). The model had an overall concordance statistic of 0·77 (95% CI 0·71-0·82) in the validation cohorts. Calibration plots indicated high agreement of predicted and observed outcomes.

INTERPRETATION

This easily applied instrument was shown to be a good predictor of the risk of late seizures after stroke in three external validation cohorts and is freely available as a smartphone app. The SeLECT score has the potential to identify individuals at high risk of seizures and is a step towards more personalised medicine. It can inform the selection of an enriched population for antiepileptogenic treatment trials and will guide the recruitment for biomarker studies of epileptogenesis.

FUNDING

None.

Stroke-related epilepsy

Stroke is the cause of about 10% of all epilepsy and 55% of newly diagnosed seizures among the elderly. Although recent advances in acute stroke therapy have improved longevity, there has been a consequent rise in the prevalence of stroke-related epilepsy (STRE). Many clinical studies make a distinction between early (within 7 days of onset of stroke) and late (beyond 7 days of onset of stroke) seizures based on presumed pathophysiological differences. Although early seizures are thought to be the consequence of local metabolic disturbances without altered neuronal networks, late seizures are thought to occur when the brain has acquired a predisposition for seizures. Overall, STRE has a good prognosis, being well controlled by antiepileptic drugs. However, up to 25% of cases become drug resistant. STRE can also result in increased morbidity, longer hospitalization, greater disability at discharge and greater resource utilization. Additional controlled trials are needed to explore the primary and secondary prevention of STRE as well as to provide high-quality evidence on efficacy and tolerability of antiepileptic drugs to guide treatment of STRE. Robust pre-clinical and clinical prediction models of STRE are also needed to develop treatments to prevent the transformation of infarcted tissue into an epileptic focus.

Early EEG predicts poststroke epilepsy

OBJECTIVE

Electroencephalography (EEG) can identify biomarkers of epileptogenesis and ictogenesis. However, few studies have used EEG in the prediction of poststroke seizures. Our primary aim was to evaluate whether early EEG abnormalities can predict poststroke epilepsy.

METHODS

A prospective study of consecutive acute anterior circulation ischemic stroke patients, without previous epileptic seizures, who were admitted to a stroke unit over 24 months and followed for 1 year. All patients underwent standardized clinical and diagnostic assessment during the hospital stay and after discharge. Video-EEG was performed in the first 72 h (first EEG), daily for the first 7 days, in case of neurological deterioration, at discharge, and at 12 months after stroke. The occurrence of epileptic seizures in the first year after stroke (primary outcome) was evaluated clinically and neurophysiologically during the hospital stay and at 12 months. A telephone interview was also performed at 6 months. The primary outcome was the occurrence of at least one unprovoked seizure (poststroke epilepsy). Secondary outcomes were the occurrence of at least one acute symptomatic seizure and (interictal and/or ictal) epileptiform activity on at least one EEG during the hospital stay for acute stroke. The first EEG variables were defined using international criteria/terminology. Bivariate and multivariate analyses with adjustment for age, admission National Institutes of Health Stroke Scale (NIHSS) score, and Alberta Stroke Program Early CT Score (ASPECTS) were performed.

RESULTS

A total of 151 patients were included; 38 patients (25.2%) had an acute symptomatic seizure and 23 (16%) had an unprovoked seizure.The first EEG background activity asymmetry and first EEG with interictal epileptiform activity were independent predictors of poststroke epilepsy during the first year after stroke (P = 0.043 and P = 0.043, respectively). No EEG abnormality independently predicted acute symptomatic seizures. However, the presence of periodic discharges on the first EEG was an independent predictor of epileptiform activity (p = 0.009) during the hospital stay.

SIGNIFICANCE

An early poststroke EEG can predict epilepsy in the first year after stroke, independently from clinical and imaging-based infarct severity.

Seizures, electroencephalographic abnormalities, and outcome of ischemic stroke patients

Objective

Seizures and electroencephalographic (EEG) abnormalities have been associated with unfavorable stroke functional outcome. However, this association may depend on clinical and imaging stroke severity. We set out to analyze whether epileptic seizures and early EEG abnormalities are predictors of stroke outcome after adjustment for age and clinical/imaging infarct severity.

Methods

A prospective study was made on consecutive and previously independent acute stroke patients with a National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 on admission and an acute anterior circulation ischemic lesion on brain imaging. All patients underwent standardized clinical and diagnostic assessment during admission and after discharge, and were followed for 12 months. Video‐EEG (<60 min) was performed in the first 72 h. The Alberta Stroke Program Early CT Score quantified middle cerebral artery infarct size. The outcomes in this study were an unfavorable functional outcome (modified Rankin Scale [mRS] ≥ 3) and death (mRS = 6) at discharge and 12 months after stroke.

Results

Unfavorable outcome at discharge was independently associated with NIHSS score (p = 0.001), EEG background activity slowing (p < 0.001), and asymmetry (p < 0.001). Unfavorable outcome 1 year after stroke was independently associated with age (p = 0.001), NIHSS score (p < 0.001), remote symptomatic seizures (p = 0.046), EEG background activity slowing (p < 0.001), and asymmetry (p < 0.001). Death in the first year after stroke was independently associated with age (p = 0.028), NIHSS score (p = 0.001), acute symptomatic seizures (p = 0.015), and EEG suppression (p = 0.019).

Significance

Acute symptomatic seizures were independent predictors of vital outcome and remote symptomatic seizures of functional outcome in the first year after stroke. Therefore, their recognition and prevention strategies may be clinically relevant. Early EEG abnormalities were independent predictors and comparable to age and early clinical/imaging infarct severity in stroke functional outcome discrimination, reflecting the concept that EEG is a sensitive and robust method in the functional assessment of the brain.