Poststroke epilepsy in the Copenhagen stroke study: incidence and predictors

Post-stroke epilepsy: From clinical predictors to possible mechanisms

BACKGROUND

Stroke is the most common cause of newly diagnosed epilepsy in the elderly, ahead of degenerative disorders, brain tumors, and head trauma. Stroke accounts for 30-50% of unprovoked seizures in patients aged ≥ 60 years. This review discusses the current understanding of epidemiology, risk factors, mechanisms, prevention, and treatment opportunities for post-stroke epilepsy (PSE).

METHODS

We performed a literature search in the PubMed and Cochrane Library databases. The keywords "stroke, epilepsy", "stroke, seizure", "post-stroke seizure", "post-stroke epilepsy" were used to identify the clinical and experimental articles on PSE. All resulting titles and abstracts were evaluated, and any relevant article was considered. The reference lists of all selected papers and reference lists of selected review papers were manually analyzed to find other potentially eligible articles.

RESULTS

PSE occurs in about 6% of stroke patients within several years after the event. The main risk factors are cortical lesion, initial stroke severity, young age and seizures in acute stroke period (early seizures, ES). Other risk factors, such as a cardioembolic mechanism or circulation territory involvement, remain debated. The role of ES as a risk factor of PSE could be underestimated especially in young age. Mechanism of epileptogenesis may involve gliosis scarring, alteration in synaptic plasticity, etc.; and ES may enhance these processes. Statins especially in the acute period of stroke are possible agents for PSE prevention presumably due to their anticonvulsant and neuroprotection effects. Antiepileptic drugs (AED) monotherapy is enough for seizure prevention in most cases of PSE; but no evidence was found for its efficiency against epileptic foci formation. The growing interest in PSE has led to a notable increase in the number of published articles each year. To aid in navigating this expanding body of literature, several tables are included in the manuscript.

CONCLUSION

Further studies are needed for better understanding of the pathophysiology of PSE and searching the prevention strategies.

Post-stroke seizures, epilepsy, and mortality in a prospective hospital-based study

Background and objectives

Post-stroke epilepsy (PSE) is a significant concern in the elderly population, with stroke being a leading cause of epilepsy in this demographic. Several factors have shown consistent associations with the risk of developing PSE, including cortical lesions, initial stroke severity, younger age, and the occurrence of early seizures. The primary objectives of this study were two-fold: (1) to determine the incidence of PSE and (2) to identify the risk factors associated with PSE in a prospective cohort of post-stroke patients.

Methods

A prospective single-hospital study was conducted, involving patients diagnosed with acute ischemic and hemorrhagic stroke. The patients were followed up for 2 years (or until death) from the time of admission. Data about seizure occurrence and recurrent stroke were collected. Kaplan-Meyer curves were used for the assessment of PSE incidence and mortality. Possible predictors of PSE and mortality were selected from between-group analysis and tested in multivariable regressions.

Results

Our study enrolled a total of 424 patients diagnosed with acute stroke. Among them, 97 cases (23%) experienced early post-stroke seizures, and 28 patients (6.6%) developed PSE. The cumulative risks of developing PSE were found to be 15.4% after hemorrhagic stroke and 8.7% after ischemic stroke. In multivariable fine and gray regression with competitive risk of death, significant predictors for developing PSE in the ischemic cohort were watershed infarction (HR 6.01, 95% CI 2.29-15.77, p < 0.001) and low Barthel index at discharge (HR 0.98, CI 0.96-0.99, p = 0.04). Furthermore, patients who eventually developed PSE showed slower recovery and presented a worse neurologic status at the time of discharge. The in-hospital dynamics of the National Institutes of Health Stroke Scale (NIHSS) were significantly worse in the PSE group compared to the non-PSE group (p = 0.01).

Discussion

A higher proportion of cases experienced early seizures compared to what has been commonly reported in similar studies. Watershed stroke and low Barthel index at discharge were both identified as independent risk factors of PSE in ischemic strokes, which sheds light on the underlying mechanisms that may predispose individuals to post-stroke epilepsy after experiencing an ischemic stroke.

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.

Diagnosis and Treatment of Poststroke Epilepsy: Where Do We Stand?

Purpose of Review

Stroke is the most common cause of seizures and epilepsy in older adults. This educational paper aims to give an update on current clinical aspects of diagnosis and treatment of poststroke epilepsy.

Recent Findings

Regarding epileptic seizures related to stroke, it is important to distinguish between acute symptomatic seizures and unprovoked seizures as they differ in their risk for seizure recurrence. In fact, after a single unprovoked poststroke seizure, a diagnosis of epilepsy can be made because there is a greater than 60% risk for further seizures. Clinical models that can predict the development of epilepsy after a stroke have been successfully established. However, treatment with anti-seizure medications is advised only after a first unprovoked poststroke seizure, as current treatments are not known to be effective for primary prevention. The management of poststroke epilepsy requires consideration of aspects such as age, drug-drug interactions and secondary vascular prophylaxis, yet evidence for the use of anti-seizure medications specifically in poststroke epilepsy is limited.

Summary

This text reviews the epidemiology and risk factors for poststroke epilepsy, explains the role of EEG and neuroimaging in patients with stroke and seizures and provides an overview on the clinical management of stroke-related acute symptomatic seizures and poststroke epilepsy.

Cortical Involvement of a Recent Infarct Contralateral to Early Focal Seizures in Ischemic Stroke

Objective To investigate the frequency and clinical characteristics of ischemic stroke patients with early seizures, especially with cortical involvement contralateral to their focal seizures. Methods We retrospectively studied patients with ischemic stroke admitted to our hospital. We compared the clinical characteristics of patients with and without early seizures (occurring within seven days of the stroke onset). In addition, we divided the patients with early focal seizures into two groups (patients with and without cortical involvement of a recent infarct contralateral to their focal seizure) and compared the clinical characteristics of the groups. Results Of the 5,806 patients with ischemic stroke, 65 (1.2%) were diagnosed with early seizures. A history of ischemic stroke (odds ratio [OR] 1.71), a history of seizures (OR 27.58), and a National Institutes of Health Stroke Scale score on admission (OR 1.07) were significant and independent factors associated with the presence of early seizures. Of these 65 patients, 56 had focal seizures, while the others had generalized or undetermined seizures. Cortical involvement of a recent infarct contralateral to their focal seizures was observed in 24 of these 56 patients (43%). Glucose and hemoglobin A1c levels were significantly higher in patients with cortical involvement of a recent infarct contralateral to their focal seizures than in those with infarcts in other regions. Conclusion These findings suggest that recent infarcts play a role as systemic causes of acute symptomatic seizures as well as an epileptogenic lesion in ischemic stroke patients with early focal seizures.

Strategic infarct location for post-stroke seizure

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The hot spots of PSS were distributed around the central region of cerebral cortex.

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We observed differences between the distribution of hot spots among patients with early-PSS and those with late-PSS.

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The specific regions of the brain are significantly associated with the development of PSS after cerebral infarction.

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The location of infarction could help clinicians assess the risk of PSS in specific post-stroke stages.

Post-stroke seizure (PSS) can have a strong negative impact on functional recovery after stroke. Researchers have identified numerous risk factors of PSS; however, the relationship between infarction location and PSS remains unclear. We recruited patients who presented with an acute cerebral infarction between 2012 and 2017 and suffered from seizures within 1 year after stroke (PSS group). PSS group was subgrouped into early-PSS and late-PSS groups based on the interval between seizure and stroke. We also recruited an equal number of acute cerebral infarction patients without post-stroke seizures during the follow-up period (Non-PSS group). All brain MRIs from the two groups were processed, whereupon normalized infarct maps from the PSS and Non-PSS groups were compared via voxel- and volumetric-based analyses. A total of 132 subjects were enrolled in the study, including PSS (n = 66, consisting of 31 early-PSS and 35 late-PSS) and Non-PSS (n = 66) patients. No significant differences were observed between the two groups in terms of stroke lateralization or severity. Image analysis revealed that the volume of infarction was larger in the PSS group than in the Non-PSS group; however, the difference did not reach the level of significance. Unlike the Non-PSS group, the PSS group presented hot spots over the left central region, left superior parietal lobule, and right frontal operculum. We observed differences between the distribution of hot spots among patients with early-PSS and those with late-PSS. We found that some brain regions were significantly associated with the development of PSS after ischemic stroke, and these regions differed between cases of early and late PSS. It appears that the location of infarction could help clinicians assess the risk of PSS in specific post-stroke stages.

Effect of Primary Prophylactic Antiseizure Medication for Seizure Prevention Following Intracerebral Hemorrhage in the ERICH Study

OBJECTIVES

Intracerebral hemorrhage (ICH) has the highest morbidity and mortality rate of any stroke subtype and clinicians often administer prophylactic antiseizure medications (ASMs) as a means of preventing post-stroke seizures, particularly following lobar ICH. However, evidence for ASM efficacy in preventing seizures and reducing disability is lacking given limited randomized trials. Herein, we report analysis from a large prospective observational study that evaluates the effect of primary prophylactic ASM administration on seizure occurrence and disability following ICH.

MATERIALS AND METHODS

Primary analysis was performed on 1630 patients with ICH enrolled in the ERICH study. A propensity score for administration of prophylactic ASM was developed and patients were matched by the closest propensity score (difference < 0.1). McNemar's test was used to compare occurrence of in-hospital seizure and disability, defined by modified Rankin Score (mRS) ≥ 3 at 3 months post ICH.

RESULTS

Of the 815 matched pairs of patients treated with primary prophylactic ASM, there was no significant difference in seizure occurrence (p = 0.4631) or disability (p = 0.4653). Subset analysis of 280 matched pairs of patients with primary lobar ICH similarly revealed no significant difference in seizure occurrence (p = 0.1011) or disability (p = 1.00) between prophylactically treated and untreated patients.

CONCLUSIONS

Although current guidelines do not recommend primary prophylactic ASM following ICH, clinical use remains widespread. Data from the ERICH study did not find an association between administering primary prophylactic ASM and preventing seizures or reducing disability following ICH, thus providing evidence to influence clinical practice and patient care.

[Risk factors for post stroke epilepsy]

Stroke is the leading cause of death and disability in the world. The prevalence of post-stroke epilepsy increases with the increase in the number of stroke cases. Epilepsy may develop in 10% of post-stroke cases and first-diagnosed seizures may develop in 55%. Most often they occur in people who have had intracerebral or subarachnoid haemorrhage. A huge number of factors influence the development of post-stroke seizures and epilepsy. The role of some of them is not in doubt. However, in most cases, the influence of a factor remains controversial and participation in the development of post-stroke epilepsy is not fully proven. The management of post-stroke epilepsy is of great clinical importance, since patients with seizures after a stroke have a higher mortality and disability than those without seizures. Attacks worsen the quality of life of patients, can slow the recovery of functions damaged as a result of a stroke, and aggravate cognitive impairment. Social consequences of post-stroke epilepsy play an important role as well.

Pediatric Ischemic Stroke and Epilepsy: A Nationwide Cohort Study

Background and Purpose

The risk of epilepsy after stroke has not been thoroughly explored in pediatric ischemic stroke. We examined the risk of epilepsy in children with ischemic stroke as well as in their first-degree relatives.

Methods

In Swedish National Registers, we identified 1220 children <18 years with pediatric ischemic stroke diagnosed 1969 to 2016, alive 7 days after stroke and with no prior epilepsy. We used 12 155 age- and sex-matched individuals as comparators. All first-degree relatives to index individuals and comparators were also identified. The risk of epilepsy was estimated in children with ischemic stroke and in their first-degree relatives using Cox proportional hazard regression model.

Results

Through this nationwide population-based study, 219 (18.0%) children with ischemic stroke and 91 (0.7%) comparators were diagnosed with epilepsy during follow-up corresponding to a 27.8-fold increased risk of future epilepsy (95% CI, 21.5–36.0). The risk of epilepsy was still elevated after 20 years (hazard ratio [HR], 7.9 [95% CI, 3.3–19.0]), although the highest HR was seen in the first 6 months (HR, 119.4 [95% CI, 48.0–297.4]). The overall incidence rate of epilepsy was 27.0 per 100 000 person-years (95% CI, 21.1–32.8) after ischemic stroke diagnosed ≤day 28 after birth (perinatal) and 11.6 per 100 000 person-years (95% CI, 9.6–13.5) after ischemic stroke diagnosed ≥day 29 after birth (childhood). Siblings and parents, but not offspring, to children with ischemic stroke were at increased risk of epilepsy (siblings: HR, 1.64 [95% CI, 1.08–2.48] and parents: HR, 1.41 [95% CI, 1.01–1.98]).

Conclusions

The risk of epilepsy after ischemic stroke in children is increased, especially after perinatal ischemic stroke. The risk of epilepsy was highest during the first 6 months but remained elevated even 20 years after stroke which should be taken into account in future planning for children affected by stroke.

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.

Research progress on the prediction of post-stroke epilepsy

Epilepsy is a common neurological disease that not only causes difficulties in the work and life activities of patients, but also brings complex social problems. Cerebrovascular disease is currently the main cause of epilepsy in the elderly. With the increased survival rate of patients after stroke, the incidence of epilepsy after stroke has also increased. Effective prediction of epilepsy after stroke is extremely crucial for the prognosis of patients, the initiation of antiepileptic therapy and the reduction of epileptic seizures. In this review, we summarize and compare the current models for the prediction of epilepsy after stroke, including the SeLECT prediction model, Post-Stroke Epilepsy Risk Scale (PoSERS), CAVE score, electroencephalogram (EEG) prediction model, and Scandinavian Stroke Scale (SSS) score, in order to provide reference for clinical practice and future research. Prediction models can be selected based on the clinical classification of cerebrovascular events. The SeLECT score prognostic model is a better choice for ischemic stroke, especially for the exclusive prediction of mild post stroke epilepsy. The CAVE score model is suitable for intra-cerebral hemorrhage patients. It is simple and offers high correlation between the risk factors and epilepsy. The PoSERS score simultaneously predicts ischemic and hemorrhagic stroke, and is superior to other methods in specificity as well as positive and negative prediction rate. The SSS score, which only measures stroke severity, is not strictly considered as a mature predictor, but it can be used as a first step screening tool. A growing number of large studies are under the way to identify risk factors of poststroke epilepsy (PSE) and to improve the inclusion of predictive indicators. New and advanced findings by EEG recordings may further improve the prediction of PSE.

Risk Factors of Post-Stroke Epilepsy in Children; Experience from a Tertiary Center and a Brief Review of the Literature

OBJECTIVES

Acute seizures and post-stroke epilepsy have been reported more frequently in patients with pediatric stroke than adults. Acute seizures in the first days of a stroke may deteriorate stroke and ischemia-related neurodegeneration and contribute to the development of post-stroke epilepsy. In this study, we aimed to investigate risk factors for the development of post-stroke epilepsy in children with arterial ischemic stroke.

MATERIALS AND METHODS

We recruited 86 children with arterial ischemic stroke. We analyzed variables, including age at admission, gender, complaints at presentation, focal or diffuse neurologic signs, neurologic examination findings, laboratory investigations that were conducted at admission with stroke (complete blood cell count, biochemical-infectious-metabolic-immunological investigations, vitamin B12 levels, vitamin D levels), neuroimaging results, etiologies, time of the first seizure, time of remote seizures, and development of neurologic deficit retrospectively. Seizures during the first six hours after stroke onset were defined as 'very early seizures'. 'Early seizures' were referred to seizures during the first 48 h. Patients who experienced two or more seizures that occurred after the acute phase of seizures were classified as 'epileptic.' A binary logistic regression analysis was used to estimate risk factors.

RESULTS

An acute seizure was detected in 59% and post-stroke epilepsy developed in 41% of our cohort. Binary logistic regression analysis demonstrated that 'very early seizures' increased epilepsy risk six-fold. Epilepsy was 16 times higher in patients with 'early seizures'. Low vitamin D levels were defined as a risk factor for post-stroke epilepsy.

CONCLUSION

Seizures in the very early period (within the first six hours) are the most significant risk factors for the development of post-stroke epilepsy Further studies regarding seizure prevention and neuroprotective therapies are needed because post-stroke epilepsy will affect long term prognosis in patients with pediatric stroke.

Prevalence and predictors of post-stroke epilepsy among Ghanaian stroke survivors

BACKGROUND

Post-stroke epilepsy (PSE) is associated with poorer quality of life, higher mortality, and greater health expenditures. We are unaware of any published reports on the frequency of and factors associated with PSE in Africa.

PURPOSE

To assess the frequency and factors associated with PSE among Ghanaian stroke survivors.

METHODS

We conducted a cross-sectional study of consecutive stroke survivors seen at an out-patient Neurology clinic enrolled into a stroke registry at a tertiary medical center in Ghana between January 2018 and March 2020. We collected baseline demographic and clinical details including diagnosis of post-stroke epilepsy, anti-epileptic medications, presence, treatment and control of vascular risk factors. Multivariate logistic regression models were constructed to identify factors associated with PSE.

RESULTS

Of 1101 stroke patients encountered, 126 had PSE (frequency of 11.4%; 95% CI of 9.6-13.5%). Mean (± SD) age among PSE vs. non-PSE patients was 57.7 (± 15.2) vs. 58.7 (± 13.9) years. Factors independently associated with PSE were being male (aOR 1.94; 95% CI: 1.32-2.86), cortical ischemic strokes (1.79; 1.12-2.87), blood pressure > 130/80 mmHg (OR 2.26; 1.06-4.79), use of antihypertensive treatment (OR 0.43; 0.23-0.79). There was an inverted J-shaped curve association between number of classes of antihypertensive drugs prescribed and occurrence of PSE, with the lowest inflection point at 3 classes (OR 0.34; 0.17-0.68).

CONCLUSION

In this convenience sample of ambulatory Ghanaian stroke survivors, one in ten had PSE. Further investigations to confirm and clarify the associations between the identified demographic and clinical characteristics are warranted.

Investigation of poststroke epilepsy (INPOSE) study: a multicenter prospective study for prediction of poststroke epilepsy

BACKGROUND AND PURPOSE

Poststroke epilepsy is a common problem in clinical practice. This study aimed to determine the predictors of poststroke epilepsy and to identify the risk factors.

METHODS

A total of 436 patients were enrolled for this study. Baseline characteristics were recorded. Patients were followed up for 3 years. According to the occurrence of late seizures (i.e., seizure occurring 8 days or later after the stroke), the patients were separated into two groups: a seizure group and a seizure-free group. Baseline characteristics were compared between the groups. Univariate and multivariate Cox regression analysis was used to identify the risk factors for occurrence of poststroke epilepsy. The study was registered in the University Hospital Medical Information Network Center Clinical Trials Registry (registration number UMIN000009659, date 28/December/2012).

RESULTS

Among the 436 patients, 26 developed late seizures-an incidence rate of 5.96%. In univariate analysis, female, subarachnoid hemorrhage, hemorrhagic lesion, lesion affecting the cortex, lesion affecting the frontal lobe, and absence of comorbidities were the significant risk factors for occurrence of epilepsy. In multivariate analysis, the independent predictors of poststroke epilepsy were hemorrhagic lesion (hazard ratio (HR) = 3.03) and lesion location in the cortex (HR = 4.64). The incidence of poststroke epilepsy in patients with both two risk factors was 15.4%.

CONCLUSIONS

Poststroke epilepsy occurs in almost 6% of patients within 3 years after stroke onset. Hemorrhagic stroke and subcortical lesion appear to be significantly associated with likelihood of developing epilepsy. Thus, prophylactic administration of antiepileptic drugs could be useful for stroke patients with these two risk factors.

Predictive value of acute EEG measurements for seizures and epilepsy after stroke using a dry cap electrode EEG system - Study design and proof of concept

The development of seizures is a common complication in patients with stroke. A recent study suggests that electroencephalography (EEG) could be useful to predict the occurrence of seizures after stroke. However, EEG is not routinely performed in the follow-up after stroke. We present the design and proof of concept of a large prospective cohort study in which we seek to evaluate the predictive usefulness of a single dry cap EEG measurement in the acute phase after stroke or transient ischemic attack (TIA) with respect to the development of poststroke epilepsy (PSE). In patients with ischemic stroke (IS), TIA, or intracerebral hemorrhage (ICH), an acute EEG measurement using a dry cap electrode EEG (dEEG) system is performed within 7 days of symptom onset. Electroencephalography data will be analyzed quantitatively and qualitatively looking for background asymmetry, different band power ratios, and epileptiform activity. The development of seizures will be assessed repeatedly during the first 2 years after stroke or TIA using a validated questionnaire. Results from the pilot phase of 11 patients showed that the dry cap EEG measurements in patients with acute stroke and TIA are feasible. In comparison with conventional EEG, a higher proportion of noise and artifacts was detected. This article is part of the Special Issue "Seizure & 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".

Early seizures after ischemic stroke: focus on thrombolysis

INTRODUCTION

Stroke is a significant underlying cause of epilepsy. Seizures due to ischemic stroke (IS) are generally categorized into early seizures (ESs) and late seizures (LSs). Seizures in thrombolysis situations may raise the possibility of other etiology than IS.

AIM

We overtook a systematic review focusing on the pathogenesis, prevalence, risk factors, detection, management, and clinical outcome of ESs in IS and in stroke/thrombolysis situations. We also collected articles focusing on the association of recombinant tissue-type plasminogen activator (rt-PA) treatment and epileptic seizures.

RESULTS

We have identified 37 studies with 36,775 participants. ES rate was 3.8% overall in patients with IS with geographical differences. Cortical involvement, severe stroke, hemorrhagic transformation, age (<65 years), large lesion, and atrial fibrillation were the most important risk factors. Sixty-one percent of ESs were partial and 39% were general. Status epilepticus (SE) occurred in 16.3%. 73.6% had an onset within 24 h and 40% may present at the onset of stroke syndrome. Based on EEG findings seizure-like activity could be detected only in approximately 18% of ES patients. MRI diffusion-weighted imaging and multimodal brain imaging may help in the differentiation of ischemia vs. seizure. There are no specific recommendations with regard to the treatment of ES.

CONCLUSION

ESs are rare complications of acute stroke with substantial burden. A significant proportion can be presented at the onset of stroke requiring an extensive diagnostic workup.

Sex differences in stroke

Sex disparities within the field of stroke, including subarachnoid hemorrhages (SAHs), have been in focus during the last 2 decades. It is clear that stroke incidence is higher in men, and also that men have their first stroke earlier than women. On the other hand, women have more severe strokes, mainly because cardioembolic strokes are more common in women. This leads to higher case fatality and worse functional outcome in women. It has often been pointed out that women more often have nontraditional stroke symptoms, and therefore may seek medical help later. After discharge from the hospital, female stroke survivors live alone in many cases and are dependent on external care. Therefore, these women frequently rate their quality of life (QoL) lower than men do. Female spouses more often provide help to their male stroke survivors than the reverse, and they accept a heavier burden. These caregivers are at high risk for depression, low QoL, and low psychologic wellbeing. SAH is a special form of stroke, often caused by a ruptured aneurysm. It is about 20% more common in women. The case fatality is high, but does not differ between the sexes.

Long-term complications of stroke and secondary prevention: an overview for primary care physicians

Despite a decline in mortality from stroke, the annual incidence in the general population is increasing. For many stroke survivors and their families, the acute stroke is the beginning of an ongoing struggle with physical impairment and subsequent disability. Over time, the immediate clinical consequences of the stroke are complicated by a variety of lesser-known medical, musculoskeletal and psychosocial difficulties. The primary care physician is best positioned to optimise chronic disease control, reduce risk and manage complications of stroke. Early screening and appropriate management is key. Instituting secondary prevention and attention to bowel and bladder problems can help reduce medical complications and re-admissions, while adequate analgesia, positioning/splinting of limbs and physiotherapy can lessen discomfort and preventable suffering. Primary care physicians can identify and treat post-stroke mood issues and involve psychological counselling for patients and caregivers. Adequate education and support may restore the independence of patients with stroke or minimise any resultant dependency.

Seizures Do Not Affect Disability and Mortality Outcomes of Stroke: A Population-Based Study

Although seizures are frequently seen after cerebrovascular accidents, their effects on long-term outcome in stroke patients are still unknown. Therefore, the aim of this study was to investigate the relationship between post-stroke seizures and the risk of long-term disability and mortality in stroke patients. This study is part of a larger population-based study. All patients were prospectively followed up by a face-to-face interview or a structured telephone interview. We enrolled 635 patients with first-ever stroke and without a history of seizures. Prevalence of ischemic stroke (IS) was 85.2%, while the remaining 14.8% of patients were affected by intracerebral hemorrhage (ICH). During the study period, 51 subjects (8%) developed post-stroke seizures. Patients with post-stroke seizures were younger, had a higher prevalence of ICH, had a more severe stroke at admission, were more likely to have an IS involving the total anterior circulation, and were more likely to have a lobar ICH than patients without seizures. Moreover, subjects with seizures had more frequently hemorrhagic transformation after IS and cortical strokes. At 24 months, the risk of disability in patients with seizures was almost twice than in those without seizures. However, the negative effect of seizures disappeared in multivariate analysis. Kaplan-Meier survival curves at 12 years were not significantly different between patients with and without post-stroke seizures. Using the Cox multivariate analysis, age, NIHSS at admission, and pre-stroke mRS were independently associated with all-cause long-term mortality. In our sample, seizures did not impair long-term outcome in patients affected by cerebrovascular accidents. The not significant, slight difference in favor of a better survival for patients with seizures may be attributed to the slight age difference between the two groups.

Family history increases the risk of late seizures after stroke

OBJECTIVE

To assess the association between a family history of epilepsy and risk of late poststroke seizures (LPS).

METHODS

This register-based cohort study was based on adult patients from the Swedish Stroke Register (Riksstroke) with stroke from 2001 to 2012 and no prior epilepsy. LPS (>7 days after stroke) and epilepsy were ascertained in cases and in their first-degree biological relatives by cross-referencing Riksstroke, the Multi-Generation Register, and the National Patient Register.

RESULTS

Of 86,550 patients with stroke, a family history of epilepsy was detected in 7,433 (8.6%), and LPS (>7 days after stroke) occurred in 7,307 (8.4%). The survival-adjusted risk of LPS was higher in patients with compared to those without a family history of epilepsy: 6.8% (95% confidence interval [CI] 6.2%-7.4%) vs 5.9% (95% CI 5.7%-6.1%) at 2 years and 9.5% (95% CI 8.7%-10.3%) vs 8.2% (95% CI 8.0%-8.4%) at 5 years. In a Cox model adjusted for age, sex, and stroke type, the hazard ratio (HR) for LPS in patients with stroke with ≥1 relative with epilepsy was 1.18 (95% CI 1.09-1.28). The increased HR remained significant with adjustments for stroke severity and in multiple sensitivity analyses. A higher risk for patients with stroke with >1 relative with epilepsy was also seen but was not significant in all Cox models.

CONCLUSIONS

Although stroke characteristics remain the most important risk factors for LPS, having a first-degree relative with epilepsy also increases the risk in a multivariate analysis. The findings highlight the need for family history assessment in patients with stroke and the need for future studies on genetic vulnerability and environmental factors that may aid in the identification of at-risk individuals.

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.

[Epileptic seizures and epilepsy after a stroke : Incidence, prevention and treatment]

Following stroke, 3-6% of patients develop acute symptomatic seizures within the first 7 days. The rate is higher after cerebral haemorrhage compared to ischaemia. In 10-12% of patients, after more than 7 days unprovoked seizures occur. Due to these low incidence rates, primary prophylaxis with antiepileptic drugs is generally not necessary. Following one acute symptomatic seizure, recurrence risk within the first 7 days post-stroke is 10-20%, generally arguing against secondary prophylaxis with an antiepileptic drug. In clinical practice however, antiepileptic drug treatment in this constellation is often initiated. If this is done, the antiepileptic drug should be withdrawn soon after the acute phase, as the long-term risk for manifestation of an unprovoked seizure is approximately 30%. Following one post-stroke unprovoked seizure, recurrence risk within the next 10 years is more than 70%, this defines epilepsy. In this case, antiepileptic drug treatment is regularly recommended.

Poststroke epilepsy: current perspectives on diagnosis and treatment

Seizures and epilepsy are quite a common outcome of arterial ischemic stroke (AIS) both in pediatric and adult patients, with distinctly higher occurrence in children. These poststroke consequences affect patients' lives, often causing disability. Poststroke seizure (PSS) may also increase mortality in patients with AIS. Early PSS (EPSS) occurring up to 7 days after AIS, late PSS (LPSS) occurring up to 2 years after the onset of AIS, as well as poststroke epilepsy (PSE) can be distinguished. However, the exact definition and cutoff point for PSE should be determined. A wide range of risk factors for seizures and epilepsy after AIS are still being detected and analyzed. More accurate knowledge on risk factors for PSS and PSE as well as possible prediction of epileptic seizures after the onset of AIS may have an impact on improving the prevention and treatment of PSE. The aim of the present review was to discuss current perspectives on diagnosis and treatment of PSS and PSE, both in adult and paediatric patients.

Risk factors and motor outcome of paediatric stroke patients

BACKGROUND

Childhood stroke causes significant morbidity and mortality. In this study, we aimed to define the presenting findings, causes, risk factors and motor outcomes of our patients.

METHODS

We retrospectively analysed patients aged from 1 month to 18 years who were diagnosed as having the first onset of stroke between January 2006 and December 2015. Presenting features, causes, risk factors, recurrence rate and motor outcomes were recorded. Motor outcome was evaluated by the gross motor function classification system.

RESULTS

Forty-seven children were included in the study. Thirty-eight (78.7%) children had an arterial stroke, 9 (19.1%) had a venous stroke. The median age at the time of presentation was 60 months (3-214). Thirty-two patients (68%) presented with a focal neurological sign and 9 presented with seizure (19.1%). Patients who had a venous stroke presented with more diffuse neurological symptoms than those who had an arterial stroke. At least one risk factor for stroke was identified in 74.5% of the patients; the most common causative factor was prothrombotic state seen in 16 patients (33.5%). Stroke recurred in 5 patients (10.6%); coexistence of multiple factors was a risk factor for recurrence. Presenting with seizure was not a facilitator for epilepsy. Thirty-two (68%) patients had a favourable motor outcome. Younger age (24 months versus 114 months) and presenting with focal neurological signs were related to non-favourable motor outcome.

CONCLUSION

Our cohort demonstrates that most of the children had a risk factor for stroke and have had favourable motor outcome. However, younger age and presenting with focal seizures are related to non-favourable motor outcome.

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.

Outcome and predictive factors in post-stroke seizures: A retrospective case-control study

PURPOSE

To evaluate clinical, radiographic, and electrophysiological features in the development and prognosis of ischemic post-stroke seizures (PSS).

METHOD

A retrospective study of 1119 patient records was performed between January 2006 and December 2016. After selection, 42 patients with seizures due to ischemic stroke were matched to a control group of 60 patients where seizures were absent. Stroke size and severity were analyzed using ASPECTS and NIHSS, respectively. Hemorrhagic transformation graded by ECASS III classification. Outcomes were assessed using the modified Rankin Scale. Fisher's exact test assessed categorical variables, and Mann-Whitney tested continuous variables.

RESULTS

Forty-two patients experienced PSS (22 females; median age 72.5 years) and were matched with 60 control subjects that had ischemic stroke without seizures. Focal seizures were present in 42.9% (18/42), and focal to bilateral convulsions in 57.1% (24/42). Stroke localization and severity did not differ (p = 0.6 and 0.21, respectively). Stroke size in anterior circulation was larger in PSS patients (median ASPECTS 6 vs 8 [p = 0.01]). Posterior circulation stroke size was similar in both groups. The presence of hemorrhage was the primary risk factor for PSS (61.9%) compared to controls (36.7%), p = 0.01. The presence of laminar necrosis (LN) (47.6% vs 21.6%, p = 0.005) and hemosiderin deposition (38.1% vs 18.3%, p = 0.02) were most predictive. PSS patients demonstrated worse outcomes than the controls (median mRS 3 vs 2, [p=<0.001]) with a median follow up of 14.8 and 20.7 months, respectively.

CONCLUSIONS

The size of anterior infarction, presence of blood products within the infarct bed, and especially LN predicted PSS.

Health-related quality of life in patients with poststroke epilepsy

BACKGROUND

Lesional epilepsy is an important long-term sequela of stroke. Data on health-related quality of life (HrQoL) in patients with poststroke epilepsy are limited. We investigated HrQoL in patients with epilepsy after ischemic stroke and identified independent HrQoL-determinants.

METHODS AND PATIENTS

All patients with acute ischemic stroke, who were permanent residents in the district Marburg-Biedenkopf (Hessia, Germany, reference population 240,000 inhabitants) were recruited within 12months in the population-based Marburg Stroke Register (MARSTREG). Follow-up visits were performed after 6, 12, and 24months, and patients who developed poststroke epilepsy were identified. Data on demographics, antiepileptic drugs (AEDs), stroke severity (National Institute of Heath Stroke Scale (NIHSS), Barthel-Index, modified Rankin Scale), depression (Geriatric Depression Scale), and HrQoL (EQ-5D and EQ VAS) were collected. A multiple regression analysis was performed to identify HrQoL-determinants.

RESULTS

Among the study participants (n=374), 23 (6.1%) developed poststroke epilepsy. The HrQoL of patients with poststroke epilepsy was reduced in comparison with patients without seizures (24-month follow-up: EuroQol Visual Analogue Scale (EuroQol-VAS): 55.3±10.7 versus 64.2±11.4, p=0.03). Seizure frequency, depression, and functional impairment (Barthel-Index) were identified as independent determinants of HrQoL. The adjustment of AEDs between 6-month and 24-month follow-ups resulted in decrease of seizure frequency by 40% and reduction of complications (dizziness by 27.8%, nausea by 52.2%, fatigue by 84.2%).

CONCLUSION

Lesional epilepsy is associated with decreased HrQoL in patients with stroke. We identified HrQoL-determinants, which would improve the management of patients with poststroke epilepsy. These determinants include proper adjustment of AEDs with reduction of seizure frequency, treatment of depression, and focused rehabilitation programs for poststroke epilepsy.

The Progress of Epilepsy after Stroke

BACKGROUND

Epilepsy is the second most common disease caused by multiple factors and characterized by an excessive discharge of certain neurons in the nervous system. Cerebrovascular disease, including stroke, is viewed as the most common cause of epilepsy in the elderly population, accounting for 30%-50% of the newly diagnosed cases of epilepsy cases in this age group.

METHODS

Data were collected from Web of Science, Medline, Pubmed, Scopus, through searching of these keywords: "Stroke" and "epilepsy".

RESULTS

Depending on the underlying cerebrovascular disease, 3%-30% of patients after stroke may develop post-stroke epilepsy (PSE), which has a negative effect on stroke prognosis and the quality of life.

CONCLUSION

In this review, we summarized new aspects emerging from research into PSE, including definition, epidemiology, risk factors, mechanism, accessory examination and treatment strategies for post-stroke epilepsy, which will enrich our knowledge of this disorder.

Incidence and management of seizures after ischemic stroke

Objective:

We conducted a meta-analysis of the incidence of early and late seizures following ischemic stroke as well as a systematic review of their pharmacologic treatment.

Methods:

Observational studies that reported incidence of seizures following ischemic stroke and those that reported treatment response to any particular antiepileptic drugs (AEDs) were included. Risk of bias was assessed by predefined study characteristics. Random effects meta-analysis was conducted for all studies where data were available for the incidence of early and late stroke-related seizures. Heterogeneity was measured with I2 statistic and sensitivity analyses were performed using prespecified variables. A qualitative synthesis of studies reporting use of AEDs for stroke-related seizures was performed.

Results:

Forty-one studies from 10,554 articles were identified; 35 studies reported incidence of stroke-related seizures and 6 studies reported effects of specific AEDs. Most studies were of low to moderate quality. Rate of early seizures was 3.3% (95% confidence interval 2.8%–3.9%, I2 = 92.8%), while the incidence of late seizures or epilepsy was 18 per 1,000 person-years (95% confidence interval 1.5–2.2, I2 = 94.1%). The high degree of heterogeneity could not be explained from the sensitivity analyses. For management of stroke-related seizures, no single AED was found to be more effective over others, though newer AEDs were associated with fewer side effects.

Conclusions:

The burden of stroke-related seizures and epilepsy due to ischemic stroke is substantial. Further studies are required to determine risk factors for epilepsy following ischemic stroke and optimal secondary prevention.

Mortality after primary intracerebral hemorrhage in relation to post-stroke seizures

Seizures after intracerebral hemorrhage are repeatedly seen. Whether the development of seizures after intracerebral hemorrhage affects survival in the long term is unknown. This study aims to determine the relation between seizures (i.e., with and without anti-epileptic therapy) and long-term mortality risk in a large patient population with intracerebral hemorrhage. We retrospectively included patients with a non-traumatic ICH in all three hospitals in the South Limburg region in the Netherlands between January 1st 2004 and December 31st 2009, and we assessed all-cause mortality until March 14th 2016. Patient who did not survive the first seven days after intracerebral hemorrhage were excluded from analyses. We used Cox multivariate analyses to determine independent predictors of mortality. Of 1214 patients, 783 hemorrhagic stroke patients fulfilled the inclusion criteria, amongst whom 37 (4.7%) patients developed early seizures (within 7 days after hemorrhage) and 77 (9.8%) developed late seizures (more than 7 days after hemorrhage). Seizure development was not significantly related to mortality risk after correction for conventional vascular risk factors and hemorrhage severity. However, we found a small but independent relation between the use of anti-epileptic drugs and a lower long-term mortality (HR = 0.32, 95% CI 0.11–0.91). In our large population, seizures and epilepsy did not relate independently to an increased mortality risk after hemorrhage.

Prospects of modeling poststroke epileptogenesis

This Review describes the current status of poststroke epilepsy (PSE) with an emphasis on poststroke epileptogenesis modeling for testing new therapeutic agents. Stroke is a leading cause of epilepsy in an aging population. Late-onset "epileptic" seizures have been reported in up to 30% cases after stroke. Nevertheless, the overall prevalence of PSE is 2-4%. Rodent models of stroke have contributed to our understanding of the relationship between seizures and the underlying ischemic damage to neurons. To understand whether acutely generated stroke events lead to a chronic phenotype more closely resembling PSE with recurrent seizures, a limited variety of approaches emerged in early 2000s. These limited methods of causing an occlusion in mice and rats show different infarct size and neurological deficits. The most often employed procedure for inducing focal ischemia is the middle cerebral artery occlusion. This mimics the pathophysiology seen in humans in terms of extent of damage to cortex and striatum. Photothrombosis and endothelin-1 models can similarly evoke episodes of ischemic stroke. These models are well suited to studying mechanisms and biomarkers of epileptogenesis or optimizing novel drug discoveries. However, modeling of PSE is tedious, is highly variable, and lacks validity; therefore, it is not widely implemented in epilepsy research. Moreover, the relevance of ischemic models to specific forms of human stroke remains unclear. Stroke modeling in young male rodents lacks clinical relevance to elderly populations and especially to women, likely as a result of sex differences. Nevertheless, because of the neuronal damage and epileptogenic insult that these models trigger, they are helpful tools in studying acquired epilepsy and prophylactic drug therapy. © 2016 Wiley Periodicals, Inc.

Post-Stroke Seizures Is Associated with Low Alberta Stroke Program Early CT Score

Background: Ischemic stroke is a leading cause of new-onset seizures. Cortical ischemia and large ischemic lesion size are among the most consistently reported risk factors for post-stroke seizures. Alberta Stroke Program Early CT Score (ASPECTS) is a simple and reliable tool for quantifying the extent of cerebral ischemia and may function as a screening tool for patients with high risk of seizure development. We investigated the association of post-stroke seizures with the extent of ischemia assessed by ASPECTS and with cortical involvement identified on non-contrast CT (NCCT). Methods: This cohort study was based on a prospectively maintained clinical database of acute ischemic stroke patients who were given intravenous tissue plasminogen activator treatment. We included patients with anterior circulation stroke admitted between January 2008 and October 2014. Patients with pre-stroke seizures were excluded. Clinical data and seizure follow-up data were collected. NCCT scans acquired both on stroke admission and at 24 h were analyzed. Logistic regression and cox regression were performed in statistical analysis. Results: A total of 348 patients (median age 73 years, interquartile range [IQR] 63-80, 55% male) were included. During follow-up (median duration 559 days, IQR 107.5-1188.5 days), 22 (6.3%) patients developed post-stroke seizures. Median time from stroke to seizure onset was 138 days (IQR 10-342 days). In univariate logistic regression, both ASPECTS on admission (OR 0.69 per 1-point increase; 95% CI 0.55-0.86; p = 0.001) and at 24 h (OR 0.80 per 1-point increase; 95% CI 0.70-0.92; p = 0.002) were significantly associated with post-stroke seizures. Cortical involvement at 24 h also correlated with seizure occurrence (OR 3.01; 95% CI 1.08-8.34; p = 0.03). Cox regression confirmed the higher risk of developing seizures at any time point in patients with lower ASPECTS value and cortical ischemia. Of note, ASPECTS was the only independent predictor for post-stroke seizures in multivariate logistic regression. Conclusion: The extent of ischemia assessed by ASPECTS and cortical involvement identified on NCCT were associated with the development of post-stroke seizures.

Selective Serotonin Reuptake Inhibitors and Poststroke Epilepsy: A Population-Based Nationwide Study

OBJECTIVE

To investigate the effects of selective serotonin reuptake inhibitors (SSRIs) on poststroke epilepsy in a population-based nationwide study.

PATIENTS AND METHODS

The SSRI group included patients who received a stroke diagnosis from January 1, 2000, through December 31, 2009, and were prescribed SSRIs after stroke. The non-SSRI group enrolled patients with stroke who were not prescribed SSRIs from the Taiwan National Health Insurance Research Database and used propensity score matching based on the index year, duration time, sex, age, type of stroke, and duration of hospitalization. Cox proportional hazards models were used to estimate the risk of epilepsy between the SSRI and comparison groups.

RESULTS

A total of 4688 patients with stroke (2344 in each of the SSRI and non-SSRI cohorts) were enrolled. The cumulative incidence of epilepsy in the SSRI group was significantly higher than that in the comparison group (log-rank P<.001). In the SSRI group, the risk of poststroke epilepsy increased 2.45-fold (95% CI, 1.69- to 3.57-fold) compared with that in the comparison group. Furthermore, the risk of poststroke epilepsy increased with the defined daily dose of SSRIs. For patients with ischemic stroke, SSRIs users had a 2.74-fold higher risk of epilepsy than non users (95% CI, 1.79- to 4.22-fold).

CONCLUSION

In this study, SSRI users had a higher risk of poststroke epilepsy than nonusers. Further study is warranted to investigate the causal relationship between SSRI exposure and poststroke epilepsy.

Clinical Profile and Changes of Serum Lipid Levels in Epileptic Patients after Cerebral Infarction

BACKGROUND

Antiepileptic drugs (AEDs) may increase development of dyslipidemia and cerebrovascular disease (CVD). We examined the clinical profile and changes of serum lipid levels after AED monotherapy in patients with poststroke epilepsy (PSE) after cerebral infarction (CI).

SUBJECTS AND METHODS

Medical records were reviewed in consecutive 2144 CI patients. Monotherapy of valproate, carbamazepine (CBZ), phenytoin (PHT), zonisamide, levetiracetam, or lamotrigine was performed in PSE patients. Serum lipid levels were measured before and at 3 months after AED treatment.

RESULTS

The prevalence of PSE was 7.0% in CI patients. The TOAST etiology disclosed large-artery atherosclerosis in 68 patients (45%), cardioembolism in 63 patients (42%), and undetermined cause in 19 patients (13%). CVD risk profile showed obesity of 18 patients (12%), current smoker of 30 patients (20%), hypertension of 75 patients (50%), diabetes mellitus of 32 patients (21%), dyslipidemia of 15 patients (10%), and atrial fibrillation of 63 patients (42%). CBZ or PHT administration increased serum total cholesterol (TC) and low-density lipoprotein-cholesterol (LDL-C) levels significantly compared to baseline and AED-untreated controls. Those levels were not increased significantly in other AED and control groups. Serum high-density lipoprotein-cholesterol and triglyceride levels did not differ statistically in all groups.

CONCLUSIONS

The prevalence of post-CI epilepsy was 7.0%. The pathogenesis contributed to atherothrombosis and cardioembolism. CBZ or PHT administration increased serum TC and LDL-C significantly. Thus, we should pay more attention to serum lipid levels in patients receiving cytochrome P450 (CYP)-induced AEDs, and might considerer switching to non-CYP-induced AEDs in patients with unfavorable serum lipid changes.

Poststroke epilepsy: update and future directions

Stroke is among the most common causes of epilepsy after middle age. Patients with poststroke epilepsy (PSE) differ in several respects from patients with other forms of structural-metabolic epilepsy; not least in age, age-related sensitivity to side effects of antiepileptic drugs (AEDs), and specific drug-drug interaction issues related to secondary-stroke prophylaxis. Encouragingly, there has lately been remarkable activity in the study of PSE. Three developments in PSE research deserve particular focus. First, large prospective trials have established the incidence and risk factors of PSE in the setting of modern stroke care. Stroke severity, cortical location, young age, and haemorrhage remain the most important risk factors. Second, although more studies are needed, epidemiological data indicate that the risk of PSE may be influenced, for instance, by statin treatment. Third, studies are emerging regarding the treatment and prognosis of PSE. Levetiracetam and lamotrigine may be well tolerated treatment options and seizure freedom is achieved in at least a similar proportion of patients as in other epilepsies. Furthermore, new animal models such as photothrombotic stroke gives hope of a more clear understanding of PSE epileptogenesis in the near future. In summary, PSE shows indications of maturing into an independent epilepsy research field. This review summarizes recent advances in our understanding of PSE and provides an update on management issues such as diagnosis, AED selection, and prognosis. Finally, future research challenges in the field are outlined.

Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

INTRODUCTION

Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT).

METHODS

We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T max, cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined.

RESULTS

Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T max (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T max (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T max 0.65.

CONCLUSION

CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT.

Seizures Following Ischemic Stroke: Frequency of Occurrence and Impact on Outcome in a Long-Term Population-Based Study

BACKGROUND AND PURPOSE

Seizures are a known complication of ischemic stroke (IS). This study assesses the long-term incidence and characteristics of poststroke seizures in a well-defined population.

METHODS

Using the Rochester Epidemiology Project medical records-linkage system, we identified all incident cases of IS among Rochester, Minnesota, residents from 1990 to 1994 and followed the patients in the comprehensive medical record through March 2014. All patients with poststroke seizures were identified, and data regarding incident IS, seizures, and status at last follow-up were analyzed.

RESULTS

We identified 489 patients with first IS. Mean follow-up was 6.5 (standard deviation 6.3) years. New onset seizures occurred in 35 patients (7.2%). Patients with poststroke seizure did not differ from those without in terms of IS etiologic subtype (P = .44) or IS risk factors (P > .05). Early seizures (within 14 days of index stroke) developed in 14 patients (40%), the majority within the first 24 hours (n = 9, 64.3%). The median time of seizure onset for the remaining 21 patients was 13.8 months. Functional outcome, as measured by modified Rankin Scale (mRS), was worse following development of poststroke seizures (mean mRS score 2.9 after IS, 3.3 following index seizure; P = .005), and mortality was higher as well, even after adjusting for IS etiologic subtype (HR 1.52, 95% confidence interval 1.07-2.16, P = .02).

CONCLUSION

Development of poststroke seizures is an infrequent but significant complication of IS, portending a worse short-term functional outcome and a higher long-term mortality rate. Seizure occurrence did not differ based on IS etiologic subtype or stroke risk factors.

Post-stroke epilepsy in Polish paediatric patients

AIM

The aim of this study was to characterize a group of children with early and late remote seizures, which occurred after arterial ischaemic stroke (AIS), and to find predictors of post-stroke seizures.

METHOD

The study group, recruited in the Department of Neuropediatrics (Medical University of Silesia, Katowice, Poland), comprised 78 individuals (range 1-18y) who had suffered a stroke: 13 participants had early seizures, occurring up to 7 days after AIS, seven participants had late remote seizures, occurring more than 7 days after AIS, and 58 participants had no seizures.

RESULTS

Post-stroke epilepsy occurred in 10 patients having post-stroke seizures. Participants affected by late remote seizures were younger, on average, than participants unaffected by seizures. The frequencies of total anterior circulation infarct (TACI) stroke subtype and focal cerebral arteriopathy (FCA) were significantly higher in the late seizure subgroup than in the subgroup without seizures (71% vs 26%, p=0.014, OR 7.17, and 100% vs 51%, p=0.015 respectively). Multivariable Cox analysis showed that age at time of stroke (p=0.027), FCA (p=0.010), and the number of infarct foci (p<0.001) were significant predictors of post-stroke seizures.

INTERPRETATION

Age at time of stroke, presence of FCA, and number of infarct foci are predictors of post-stroke seizures in Polish paediatric patients.

Retracted: Post-stroke epilepsy in Polish paediatric patients

The above article, published online on 5 October 2013 in Wiley Online Library Early View (http://onlinelibrary.wiley.com/), has been retracted by agreement between the authors, the journal Editor in Chief, Dr Peter Baxter, and John Wiley & Sons Ltd. The retraction has been agreed due to several errors in the statistics. These errors make interpretation of the data difficult and the validity of the conclusions questionable.

Are Early Seizures Predictive of Epilepsy after a Stroke? Results of a Population-Based Study

BACKGROUND

In addition to determining the cumulative incidence and risk factors for early seizures (ES), late seizures (LS) and post stroke epilepsy (PSE), we aimed at checking if ES represented a risk factor for epilepsy and if early treatment after ES prevented the occurrence of subsequent seizures.

METHODS

This study was part of a 2-year prospective community-based registry of all cerebrovascular events in the district of Udine (153,312 inhabitants), North-Eastern Italy, between April 1, 2007 and March 31, 2009. People with transient ischemic attacks (TIAs) were excluded from this study.

RESULTS

In all, 782 cases of stroke (79.28% ischemic, 14.83% hemorrhagic, 3.20% subarachnoid hemorrhage and 2.69% undetermined) were identified. The incidence of ES, LS and PSE was 5.10, 3.14 and 2.22%, respectively. Intracerebral hemorrhage, subarachnoid hemorrhage, stroke of undetermined origin and hyponatremia, represented risk factors for ES (p < 0.05). Among ischemic strokes, ES risk factors were hyponatremia (p = 0.024) and hemorrhagic transformation (p = 0.046). LS risk factors were younger age (p = 0.004) and cortical location of stroke (p = 0.004). Within ischemic strokes, LS risk factors were younger age (p = 0.020) and cortical location (p < 0.0001). Within intracerebral hemorrhages, the only risk factor for LS was the presence of a previous ES (p = 0.017). PSE risk factors were the same as for LS.

CONCLUSIONS

All acute conditions related to the occurrence of stroke are implicated in the pathogenesis of ES, which becomes a risk factor for LS only in the setting of intracerebral hemorrhages. Therefore, early antiepileptic treatment is needed only in this situation.

The pooled incidence of post-stroke seizure in 102 008 patients

BACKGROUND

Post-stroke seizures and epilepsy may worsen the recovery and increase the disability of stroke patients during their daily lives. However, few meta-analysis studies have been conducted on post-stroke seizures incidence. We carried on a meta-analysis on the incidence rate of post-stroke seizures and associated factors.

METHODS

We searched the Medline, Embase, Web of Science, Science Citation Index, and Cochrane Library electronic databases (1990-2013) to identify observational studies of post-stroke seizures. Two authors independently extracted the related information from all included studies. We calculated the pooled incidence by meta-analysis using the software R version 12.3.

RESULTS

A total of 34 longitudinal cohort studies involving 102 008 patients were included in our meta-analysis. The pooled incidence rate of post-stroke seizures was found to be 0.07 [95% confidence interval (CI), 0.05-0.09] while the rate of post-stroke epilepsy (PSE) was 0.05 (95% CI, 0.04-0.06). The incidence of post-stroke seizures in hemorrhagic stroke (0.10, 0.08-0.13) was much higher than in ischemic stroke (0.06, 0.04-0.08) and when the cortical region was involved (0.15, 0.10-0.21).

CONCLUSIONS

Our meta-analysis showed that seizures occurred in about 6.93% of people with stroke. Seizures occurred more commonly after hemorrhagic stroke and when stroke occurred in the cortical region.

Risk factors for post-stroke seizures: a systematic review and meta-analysis

PURPOSE

To perform a systematic review and meta-analysis to identify risk factors associated with early seizure (ES) or late seizure (LS) onset in adults following stroke.

DATA SOURCES

Electronic databases (MEDLINE and EMBASE), archives of stroke or epilepsy patients, and bibliographies of relevant articles, which were written in English.

STUDY SELECTION

We included studies published since 1990 that reported the stroke and seizure outcomes of adult patients during follow-up. We independently performed title, abstract and full-text screening and resolved disagreements through discussion.

DATA EXTRACTION

Two authors performed the data extraction. We recorded all possible risk factors predictive of seizure onset.

DATA SYNTHESIS

We used odds ratios (ORs) or the mean difference (MD) to compare the pooled rates of seizure onset between the exposed group and the non-exposed group. All meta-analyses were performed with Review Manager Software.

RESULTS

Intracerebral hemorrhage (OR=1.88, 95% CI=1.43-2.47), cerebral infarction with hemorrhagic transformation (OR=3.28, 95% CI=2.09-5.16), stroke severity (OR=3.10, 95% CI=2.00-4.81, p<0.01, I(2)=0%; MD=3.98, 95% CI=1.06-6.90, p<0.01), and alcoholism (OR=1.70, 95% CI=1.23-2.34, p<0.01) were associated with a significantly greater probability of ES occurrence. There were significant effects of cortical involvement (OR=2.50, 95% CI=1.93-3.23) and stroke severity (MD=5.72, 95% CI=4.23-7.22, p<0.01, I(2)=0) on LS onset. However, there was no significant difference in the probability of single LS episode between patients with intracerebral hemorrhage and infarction stroke (OR=1.20, 95% CI=0.92-1.55).

CONCLUSIONS

Evidence suggests that cortical involvement, stroke subtypes and stroke severity are significant predictors of seizure onset following stroke. However, we did not find a significant difference in the rate of onset of single LS episodes between patients with intracerebral hemorrhage and cerebral infarction.

Seizures after decompressive hemicraniectomy for ischaemic stroke

OBJECTIVE

The risk of seizures after malignant middle cerebral artery (MCA) infarction with decompressive hemicraniectomy (DHC) is uncertain. Also unknown is how this complication influences survivors' recovery and quality of life.

METHODS

We retrospectively reviewed medical charts of all patients admitted to Harborview Medical Center between 1 January 2002 and 31 June 2011 for space-occupying MCA ischaemic stroke and who underwent DHC. Survivors and their surrogates were invited to participate in a telephone or in-person interview.

RESULTS

Fifty-five patients were followed for a median of 311 days (IQR 134-727). Twenty-seven patients (49%) had seizures, 25 (45%) developed epilepsy and 21 (38%) achieved moderate disability or better (modified Rankin Scale score ≤3) by 1 year after stroke onset. The only factor significantly associated with seizure occurrence was male gender. Median time from stroke to first seizure was 222 days, with a cluster of first seizures within weeks after cranioplasty; only two of the first seizures occurred right around the time of stroke onset. Follow-up time was significantly longer for patients with seizures (605 days, IQR 297-882) than for those without (221 days, IQR 104-335). Of the 20 patients interviewed, 12 achieved moderate disability or better, 15 experienced a seizure with 6 indicating the seizure was a major drawback. Regardless, all 20 would have chosen DHC again.

CONCLUSIONS

In this case series, patients were at high risk of developing seizures after malignant MCA stroke with DHC, especially after cranioplasty. Assuming these findings are replicated, means should be sought to reduce the occurrence of this complication.