Analysis of risk factors for first seizure after stroke in Chinese patients

The Relative Impact of Clinical and Investigational Factors to Predict the Outcome in Stroke Patients

OBJECTIVE

As stroke is still considered a significant cause of mortality and morbidity, it is crucial to find the factors affecting the outcome in these patients. We aimed to interpret the various clinical and investigational parameters and establish their association with the outcome in stroke patients.

MATERIALS AND METHODS

This is a retrospective, cross-sectional study, conducted in the Department of Neurology between June 2019 to November 2021. The study involved the review and analysis of medical records pertaining to 264 patients, admitted with the diagnosis of stroke. Various clinical, radiological, and electroencephalographic (EEG) patterns in stroke patients were analyzed and their association with outcome was established. The association between the studied variables was performed by the logistic regression (LR) and presented as odds ratio (OR) and 95% confidence interval (CI).

RESULTS

The study sample consisted of 264 patients. Males comprised 165 (62.5%) with the mean participant age of 57.17 ± 18.7 3 years (range: 18-94). Patients younger than 50 years had a better likelihood of a good outcome in comparison to patients older than 50. The admission location was the most significant factor in predicting the outcome ( P = 0.00) in favor of inpatient department and outpatient department (OPD), in contrast to patients admitted directly to intensive care unit (ICU). Normal EEG was associated with good outcome ( P = 0.04; OR, 3.3; CI, 1.01-10.88) even after adjustment of the confounders, whereas patients having marked EEG slowing had a poor outcome ( P = 0.05; OR, 2.4; CI, 0.65-8.79). Among the clinical parameters, hemiparesis ( P = 0.03), trauma ( P = 0.01), generalized tonic-clonic seizures (GTC) ( P = 0.00), and National Institutes of Health Stroke Scale of more than 4 were more likely associated with a poor outcome as well as the presence of intracranial hemorrhage (ICH) or infarction in the cortical and cortical/subcortical locations were associated with poor outcomes. After adjustment of confounders, the factors found to have prognostic significance in favor of good outcomes were inpatients or OPD referrals and normal EEG while direct admission to ICU, marked slowing on EEG, and presence of ICH were found to be associated with poor outcome.

CONCLUSION

Certain patterns are predictive of good or worse outcomes in stroke patients. Early identification of these factors can lead to early intervention, which in turn might help in a better outcome. The results of the study, therefore, have some prognostic significance.

Large datasets from Electronic Health Records predict seizures after ischemic strokes: A Machine Learning approach

Objective

To develop an artificial intelligence, machine learning prediction model for estimating the risk of seizures 1 year and 5 years after ischemic stroke (IS) using a large dataset from Electronic Health Records.

Background

Seizures are frequent after ischemic strokes and are associated with increased mortality, poor functional outcomes, and lower quality of life. Separating patients at high risk of seizures from those at low risk of seizures is needed for treatment and clinical trial planning, but remains challenging. Machine learning (ML) is a potential approach to solve this paradigm.

Design/Methods

We identified patients (aged ≥18 years) with IS without a prior diagnosis of seizures from 2015 until inception (08/09/22) in the TriNetX Research Network, using the International Classification of Diseases, Tenth Revision (ICD-10) I63, excluding I63.6 (venous infarction). The outcome of interest was any ICD-10 diagnosis of seizures (G40/G41) at 1 year and 5 years following the index IS. We applied a conventional logistic regression and a Light Gradient Boosted Machine algorithm to predict the risk of seizures at 1 year and 5 years. The performance of the model was assessed using the area under the receiver operating characteristics (AUROC), the area under the precision-recall curve (AUPRC), F1 statistic, model accuracy, balanced accuracy, precision, and recall, with and without anti-seizure medication use in the models.

Results

Our study cohort included 430,254 IS patients. Seizures were present in 18,502 (4.3%) and (5.3%) patients within 1 and 5 years after IS, respectively. At 1-year, the AUROC, AUPRC, F1 statistic, accuracy, balanced-accuracy, precision, and recall were respectively 0.7854 (standard error: 0.0038), 0.2426 (0.0048), 0.2299 (0.0034), 0.8236 (0.001), 0.7226 (0.0049), 0.1415 (0.0021), and 0.6122, (0.0095). Corresponding metrics at 5 years were 0.7607 (0.0031), 0.247 (0.0064), 0.2441 (0.0032), 0.8125 (0.0013), 0.7001 (0.0045), 0.155 (0.002) and 0.5745 (0.0095).

Conclusion

Our findings suggest that ML models show good model performance for predicting seizures after IS.

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.

Risk Factors Associated with Epilepsy Related to Cerebrovascular Disease: A Systematic Review and Meta-Analysis

Background and Objective

Stroke is one of the most frequent neurological syndromes in the adult population and the cause of 10% of all diagnosed epilepsies. It is attributed to the origin of up to 50% of them in adults >60 years of age. Although a few risk factors have been described and considered when modeling predictive tools, this aspect is still clinically complex. The objective of this study is to describe and compare predictor scales of post stroke epilepsy (PSE) in adult patients with better performance.

Methods

A systematic review and meta-analysis were performed of studies published between 2010 and 2020 and found in PubMed, Scopus, EMBASE, LILACS, BVS, Google Scholar, and CENTRAL databases. Sixteen studies were included with a total of 298,694 patients with a diagnosis of stroke, 5590 presented late seizures (LS).

Results

Hemorrhage, cortical involvement, and early seizure were the elements most associated with the risk of presenting late seizures. The SeLECT score demonstrated a low risk of bias with a high predictive ability in patients with ischemic stroke (AUC: 0.77 [95% CI: 0.71-0.82]). In patients with hemorrhagic stroke, the CAVE score demonstrated adequate predictive ability (AUC: 0.81 [95% CI: 0.76-0.86]), but an uncertain risk of bias. Research has established risk factors for post ictal epilepsy; however, the numerous ways of assessing data in studies and the difference in their designs make the task of producing a predictive scale that covers the most important risk factors and is reliable for application in the clinical setting, regardless of stroke etiology, very arduous.

Conclusion

Hemorrhage, cortical involvement, and early seizure are associated with an increased risk of post ictal epilepsy. Also, elements such as age, traditional vascular risk factors, and functional assessment failed to reflect statistical significance. Finally, further research is required to refine the available predictive tools.

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.

Clinical risk factors related to post-stroke epilepsy patients in Indonesia: a hospital-based study

Background

Stroke had been accounted to cause almost 50% of epilepsy in the elderly and may lead to poor functional outcomes. Many studies examining the risk factors have been conducted despite showing inconsistent results and currently still difficult to predict the occurrence of post-stroke epilepsy. The study aimed to determine risk factors related to post-stroke epilepsy that influence clinical seizure, electroencephalography (EEG), and functional outcome of patients. Analytic retrospective case–control study was conducted with a total sampling of 62 samples of post-stroke epilepsy and 62 samples of control from all stroke patients in the Neurology Clinic from January 2019 to December 2021. Epilepsy was classified according to the criteria of the International League Against Epilepsy (ILAE) in 2017. The relevant demographic and clinical data were collected.

Result

The study involved 62 patients in the case group (average age of onset = 57.69; 42 men, 20 women; 51 ischemic stroke, 11 hemorrhagic stroke) and 62 patients in the control group (average age of onset = 56.90; 24 men, 38 women; 52 ischemic stroke, 10 hemorrhagic stroke). We found that 31 patients had focal-to-bilateral seizures, 26 patients had generalized seizures and 5 patients had focal seizures. Men (p = 0.001; OR 3.325) and NIHSS Score (p = 0.027; OR 5.094) had significant correlations with post-stroke epilepsy. Ischemic stroke had a significant correlation (p = 0.008) with seizure onset. Women also had a significant correlation (p = 0.012) with EEG abnormalities. The study found that 59 of 62 post-stroke epilepsy patients had poor functional outcomes (mRS > 2).

Conclusion

Our study confirmed that most patients had focal-to-bilateral seizure patterns that occurred in 1–2 years after stroke, and had poor functional outcomes. Men had 3.325 times more likely to develop post-stroke epilepsy than women. Also, NIHSS score ≥ 15 correlated and 5.094 times more likely to develop post-stroke epilepsy. Ischemic stroke had a peak of epilepsy onset at 1–2 years after stroke and women had significant showing abnormalities on EEG recording than men.

Post-stroke seizures: risk factors and management after ischemic stroke

Stroke is the leading cause of epilepsy in the elderly, ahead of degenerative diseases, tumors and head injuries. It constitutes a significant complication and a considerable comorbidity. The aim of our study was to describe the main factors implicated in the occurrence of post-stroke seizures and to identify the predictors of seizure recurrence. We conducted a descriptive, retrospective, monocentric study from January 2010 to December 2019, including patients who presented seizures following an ischemic stroke. We classified these seizures according to the International League Against Epilepsy (ILAE) into acute symptomatic seizures (ASS) if they occur within seven days of stroke, and unprovoked seizures (US) if they occur after more than one week. Clinical, para-clinical, therapeutic and follow-up data were statistically analyzed and compared. A total of 52 patients were included (39 men, 13 women; median age 55.1 years). 21 cases (40%) had ASS and the remaining 31 cases (60%) presented US. Young age below 65 years (71%), middle cerebral artery infarcts (83%), and cortical localization (87%) were the main factors depicted in our series. Parietal lobe infarction was more associated with US than ASS (p = 0.035). 24 patients (46%) have presented a recurrence of seizures (8/21 of ASS and 16/31 of US). The use of sodium valproate in monotherapy was identified as a recurrence risk factor (p = 0.013). In patients with post-stroke seizures, parietal lobe infarcts are more associated with US. We identified a higher risk of seizure recurrence in patients treated with sodium valproate monotherapy.

Stroke-related early seizures: clinical and neurophysiological study in a sample of Egyptian population

Background

Available data collected from patients of different types of acute cerebrovascular strokes can detect risk factors, clinical data (including semiology of seizures), EEG findings and functional outcome of these patients. Stroke, both ischemic and hemorrhagic, has been considered an essential cause of epilepsy, especially in the elderly. Complications of acute stroke during the early days after the insult determine the ultimate outcome of events. The aim of this study is to determine the clinical and neurophysiological characteristics of stroke patients with or without clinical evident fits for early detection and better management.

Results

The brain imaging of the cases group who developed seizures showed that 50% of the cases have arterial ischemic infarction, 30% venous infarction, 6.67% ischemic infarction with haemorrhagic transformation, 6.67% intracerebral haemorrhage and 6.67% have subarachnoid haemorrhage. Based on the 2017 ILAE criteria, 43.33% of the patients developed focal to bilateral tonic clonic seizures, 33.33% developed focal aware seizures, 16.67% of the patients developed generalized tonic clonic seizures and 6.67% of the patient developed status epilepticus. EEG findings of the group of patients who developed seizures showed, focal slowing in 46.67%, focal epileptiform activity in 13.33%, focal activity with secondary generalization in 10%, PLEDS in 6.67%, generalized epileptiform activity in 6.67%, generalized slowing in 6.67% and normal EEG in 10% of the patients. Non convulsive status was found in 2 patients (6.67%) of the group with altered mental status. There was no PLEDS in EEG of group of patients without clinical seizures. This study did not find age and sex differences in patients with and without seizures. In addition, it was found that there was no statistically significant difference between the three groups as regard history of diabetes mellitus, hypertension, heart diseases, atrial fibrillation, carotid stenosis and collagen diseases. There was no significant relationship between seizures and early treatment with Rtpa and thrombectomy.

Conclusions

Focal to bilateral tonic clonic and focal aware seizures were the most prevalent type of early onset seizures after stroke, followed by generalized tonic clonic seizures and status epilepticus. Most EEG findings in this study were focal slowing, focal epileptiform activities, generalized epileptiform activities and PLEDS.

A step-by-step guide for the diagnosis and management of hyponatraemia in patients with stroke

Hyponatraemia is common in patients with stroke and associated with adverse outcomes and increased mortality risk. The present review presents the underlying causes and provides a thorough algorithm for the diagnosis and management of hyponatraemia in stroke patients. Concomitant diseases and therapies, such as diabetes, chronic kidney disease and heart failure, along with diuretics, antidepressants and proton pump inhibitors are the most common causes of hyponatraemia in community. In the setting of acute stroke, the emergence of hyponatraemia might be attributed to the administration of hypotonic solutions and drugs (ie. mannitol and antiepileptics), poor solute intake, infections, as well as stroke-related conditions or complications, such as the syndrome of inappropriate secretion of antidiuretic hormone, cerebral salt wasting syndrome and secondary adrenal insufficiency. Diagnostically, the initial step is to differentiate hypotonic from non-hypotonic hyponatraemia, usually caused by hyperglycaemia or recent mannitol administration in patients with stroke. Determining urine osmolality, urine sodium level and volume status are the following steps in the differentiation of hypotonic hyponatraemia. Of note, specific parameters, such as fractional uric acid and urea excretion, along with plasma copeptin concentration, may further improve the diagnostic yield. Therapeutic options are based on the duration and symptoms of hyponatremia. In the case of acute or symptomatic hyponatraemia, hypertonic saline administration is recommended. Hypovolaemic chronic hyponatremia is treated with isotonic solution administration. Although fluid restriction remains the first-line treatment for the rest forms of chronic hyponatraemia, therapies increasing renal free water excretion may be necessary. Loop diuretics and urea serve this purpose in patients with stroke, whereas sodium-glucose transport protein-2 inhibitors appear to be a promising therapy. Nevertheless, it is yet unclear whether the appropriate restoration of sodium level improves outcomes in such patients. Randomized trials designed to compare therapeutic strategies in managing hyponatraemia in patients with stroke are required.

Epilepsy in Cerebrovascular Diseases: A Narrative Review

BACKGROUND

Epilepsy is a common comorbidity of cerebrovascular disease and an increasing socioeconomic burden.

OBJECTIVE

We aimed to provide an updated comprehensive review on the state of the art about seizures and epilepsy in stroke, cerebral haemorrhage, and leukoaraiosis.

METHODS

We selected English-written articles on epilepsy, stroke, and small vessel disease up until December 2021. We reported the most recent data about epidemiology, pathophysiology, prognosis, and management for each disease.

RESULTS

The main predictors for both ES and PSE are the severity and extent of stroke, the presence of cortical involvement and hemorrhagic transformation, while PSE is also predicted by younger age at stroke onset. Few data exist on physiopathology and seizure semiology, and no randomized controlled trial has been performed to standardize the therapeutic approach to post-stroke epilepsy.

CONCLUSION

Some aspects of ES and PSE have been well explored, particularly epidemiology and risk factors. On the contrary, few data exist on physiopathology, and existing evidence is mainly based on studies on animal models. Little is also known about seizure semiology, which may also be difficult to interpret by non-epileptologists. Moreover, the therapeutic approach needs standardization as regards indications and the choice of specific ASMs. Future research may help to better elucidate these aspects.

Poststroke Seizure and Epilepsy: A Review of Incidence, Risk Factors, Diagnosis, Pathophysiology, and Pharmacological Therapies

Stroke is the most common cause of epilepsy and ultimately leads to a decrease in the quality of life of those affected. Ischemic and hemorrhagic strokes can both lead to poststroke epilepsy (PSE). Significant risk factors for PSE include age < 65age less than 65 years, stroke severity measured by the National Institutes of Health Stroke Scale (NIHSS), cortical involvement, and genetic factors such as TRPM6 polymorphism. The diagnosis of PSE is made by using imaging modalities, blood biomarkers, and prognostic criteria. Electroencephalography (EEG) is currently the gold standard to diagnose PSE, while new combinations of modalities are being tested to increase diagnostic specificity. This literature review uncovers a newly found mechanism for the pathology of poststroke epilepsy. The pathogenesis of early-onset and late-onset is characterized by sequelae of neuronal cellular hypoxia and disruption of the blood-brain barrier, respectively. Interleukin-6 is responsible for increasing the activity of glial cells, causing gliosis and hyperexcitability of neurons. Epinephrine, high-mobility group protein B1, downregulation of CD32, and upregulation of HLA-DR impact the pathology of poststroke epilepsy by inhibiting the normal neuronal immune response. Decreased levels of neuropeptide Y, a neurotransmitter, act through multiple unique mechanisms, such as inhibiting intracellular Ca²⁺ accumulation and acting as an anti-inflammatory, also implemented in the worsening progression of poststroke epilepsy. Additionally, CA1 hippocampal resonant neurons that increase theta oscillation are associated with poststroke epilepsy. Hypertensive small vessel disease may also have an implication in the temporal lobe epilepsy by causing occult microinfarctions. Furthermore, this review highlights the potential use of statins as primary prophylaxis against PSE, with multiple studies demonstrating a reduction in incidence using statins alone, statins in combination with antiepileptic drugs (AEDs), and statins with aspirin. The evidence strongly suggests that the second generation AEDs are a superior treatment method for PSE. Data from numerous studies demonstrate their relative lack of significant drug interactions, increased tolerability, and potential superiority in maintaining seizure-free status.

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.

Assessment of the incidence and risk factors of early poststroke seizures in Lebanese patients

BACKGROUND

Early seizures have been recognized as serious complications of ischemic strokes where the data are limited among Lebanese patients. This study aimed to assess the incidence and risk factors of early seizures postischemic stroke and to determine the effect of early seizures on functional outcome among Lebanese stroke patients.

METHODS

This was a retrospective observational study conducted between January 2017 and March 2020 on patients with acute ischemic strokes at two tertiary hospitals in Lebanon. Data were collected from patients' medical records at each site through a well-designed data collection sheet. Early seizures were defined as seizures occurring within 7 days after acute stroke. Functional outcome was assessed at discharge, according to modified Rankin scale (mRS).

RESULTS

Of 140 enrolled patients, early seizure developed in 12 patients (8.6%) with mean age of 68.42 ± 9.89 years and 8 (67%) were females. Independent risk factors for early seizure development were female gender and cortical involvement. Moreover, early seizure development was not associated with higher disability and mortality at hospital discharge.

CONCLUSION

The findings of the study highlight that early seizures occurred more commonly in patients with cortical involvement and female gender. In addition, early seizures did not impair functional outcome in our study, however; further studies are needed to predict patients at risk of early seizure so that appropriate prevention and treatment strategies can be implemented promptly.

Frequency and factors associated with post-stroke seizures in a large multicenter study in West Africa

BACKGROUND

Post-stroke seizures (PSS) are associated with significant morbidity and mortality across the globe. There is a paucity of data on PSS in Africa.

PURPOSE

To assess the frequency and factors associated with PSS by stroke types across 15 hospitals in Nigeria and Ghana.

METHODS

We analyzed data on all stroke cases recruited into the Stroke Investigative Research and Educational Network (SIREN). We included adults aged ≥18 years with radiologically confirmed ischemic stroke (IS) or intracerebral hemorrhage (ICH). PSS were defined as acute symptomatic seizures occurring at stroke onset and/or during acute hospitalization up until discharge. We used logistic regression to estimate adjusted odds ratios (aOR) with 95% Confidence Interval.

RESULTS

Among 3344 stroke patients, 499 (14.9%) had PSS (95% CI: 13.7-16.2%). The mean duration of admission in days for those with PSS vs no PSS was 17.4 ± 28.6 vs 15.9 ± 24.7, p = 0.72. There were 294(14.1%) PSS among 2091 ischemic strokes and 159(17.7%) among 897 with ICH, p = 0.01. The factors associated with PSS occurrence were age < 50 years, aOR of 1.59 (1.08-2.33), National Institute of Health Stroke Score (NIHSS), 1.29 (1.16-1.42) for each 5 units rise and white cell count 1.07 (1.01-1.13) for each 10^3 mm3 rise. Factors associated with PSS in ischemic were NIHSS score, aOR of 1.17 (1.04-1.31) and infarct volume of 10-30 cm3 aOR of 2.17(1.37-3.45). Among ICH, associated factors were alcohol use 5.91 (2.11-16.55) and lobar bleeds 2.22 (1.03-4.82).

CONCLUSION

The burden of PSS among this sample of west Africans is substantial and may contribute to poor outcomes of stroke in this region. Further longitudinal studies are required to understand the impact on morbidity and mortality arising from PSS in Africa.

Risk factors for early-onset seizures after stroke: A systematicreview and meta-analysis of 18 observational studies

OBJECTIVES

To systematically evaluate the risk factors of early-onset seizures after stroke, in order to better provide evidence-based results for early detection, identification, targeted prevention, and treatment of this disease.

METHODS

PubMed, EMBASE, The Cochrane Library, CNKI, and WanFang databases were searched to collect relevant studies on the risk factors of early-onset seizures after stroke from January 2010 to January 2020. Meta-analysis of all included studies was performed by using RevMan version 5.3 and Stata version 14.0 software.

RESULTS

Eighteen case-control studies with a total sample size of 13,289 cases, including 813 cases with early-onset seizures after stroke, and 12,476 cases with non-early-onset seizures after stroke were included. The results of meta-analysis showed that cortical involvement [Odds Ratio (OR) = 5.00, 95%Confidence Interval (CI) (2.85, 8.74), p < .00001], cerebral infarction with hemorrhagic transformation [OR = 2.77, 95%CI (1.87, 4.11), p < .00001] and intracerebral hemorrhage [OR = 1.83, 95%CI (1.13, 2.97), p = .01]-related factors showed greater association with the occurrence of early-onset seizures after stroke.

CONCLUSIONS

These findings suggest that cortical involvement, intracerebral hemorrhage, and cerebral infarction with hemorrhagic transformation are important predictors and risk factors for early seizures after stroke, while the patient's gender, age, NHISS score, alcoholism, smoking, high blood pressure, diabetes, atrial fibrillation, dyslipidemia, receiving surgical treatment, and reperfusion therapy showed no association with the occurrence of early-onset seizures after 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.

Meta-analyzing count events over varying durations using the piecewise Poisson model: The case for poststroke seizures

Meta-analyzing count data can be challenging when follow-up time varies across studies. Simply pooling aggregate data over time-periods would result in biased estimates, which may erroneously inform clinical decision-making. In this study, we exploit the convolution property of the Poisson distribution to develop a likelihood for observed cumulative counts over varying follow-up periods, where different Poisson distributions are used to represent the data generating processes for the latent counts in pre-defined successive intervals of follow-up. We illustrate this approach using an example of poststroke seizures, a case in which risk may change over time, and mimic its survival duration with time-varying hazard. Data were extracted from observational studies (1997-2016) reporting poststroke seizures over a maximum of 10 years of follow-up. Three clinically meaningful follow-up time intervals were considered: 0 to 7 days, 8 to 365 days, and 1 to 10 years poststroke. External validation was performed using claims data. Results suggest the incidence rate of seizures was 0.0452 (95% confidence interval: 0.0429, 0.0475), 0.0001 (0, 0.016), and 0.0647 (0.0441, 0.0941) for the three time intervals, respectively, indicating that the risk of seizures changes over time poststroke. We found that the model performed well against the incidence rate of seizures among actual retrospective cohort from claims data. The piecewise Poisson model presents a flexible way to meta-analyze count data over time and mimic survival curves. The results of the piecewise Poisson model are readily interpretable and may spur meaningful clinical action. The method may also be applied to other diseases. HIGHLIGHTS: It is challenging to perform a meta-analysis when follow-up time varies across studies. Ideally, outcomes over different time-periods should be pooled with individual patient-level data (IPD). A new model was developed to meta-analyze count data over time using aggregate-level data from previous published studies. The piecewise Poisson model could be a useful tool to estimate time-vary hazards given available data, and mimic survival curves over time which would be readily interpretable.

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.

Monitoring for Poststroke Seizures

It is unpredictable which stroke survivors will experience a seizure following a stroke. Stroke is a major cause of seizures. Critical care nurses need to know the risk factors, type of stroke at risk, stroke location, and severity for the poststroke patient who is at risk for an early or late seizure. Poststroke seizures require appropriate nursing assessments, management, and support.

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.

Early post-stroke seizures in a sample of Egyptian patients with first-ever stroke

Background

Cerebrovascular stroke is considered as the most common cause of symptomatic seizures. Post-stroke seizures herald a poor functional outcome, a high mortality rate, and a long in-hospital duration of stay.

Aim

To assess the incidence and risk factors responsible for early seizures after the first-ever cerebral stroke, and its relation to the functional outcome and the in-hospital mortality following stroke as well as the duration of stay.

Patients and Methods

150 patients with first-ever stroke, who were admitted in an intensive care and stroke unit of the Neurology Department of Zagazig University Hospitals, Egypt, within the first 24 hours of stroke onset were included in the study. Early seizures (within 7 days of stroke onset), stroke severity (National Institutes of Health stroke scale; NIHSS), radiological data, functional outcome (Barthel index), in-hospital mortality and duration of stay were collected and analyzed.

Results

The incidence of early seizures associated with first-ever stroke was 9.3%. Risk factors for early seizures were intracerebral hemorrhage (ICH) [odds ratio (OR) = 3.2, P = <0.001), cortical lesions (OR = 2.8, P = <0.05), and a large lesion size (OR = 2, P= <0.05). Patients with early seizures had lower scores on the Barthel index than those without seizures (7.5 ± 4.1 versus 10.5 ± 3.5), had higher discharge National Institutes of Health Stroke scale (NIHSS) scores, had a higher in-hospital mortality rate (35.7% versus 6.6% in patients without seizures) and duration of stay (19.4 ± 6.5 versus 10.7 ± 4.2 days respectively).

Conclusion

The incidence of early post-stroke seizures was high in our study and was positively associated with a poor functional outcome, a higher in-hospital mortality rate and a longer duration of in-hospital stay. The most important risk factors were ICH, the cortical site of involvement and a large size of the lesion.

Association of Hyponatremia and Risk of Short- and Long-Term Mortality in Patients with Stroke: A Systematic Review and Meta-Analysis

BACKGROUND

Hyponatremia is the most common electrolyte disorder in the clinic practice and it is closely related to the prognosis of various diseases. Studies reported that hyponatremia increased the risk of stroke mortality while yielded inconsistent findings during the follow-up period. Thus, a systematic review and meta-analysis to assess the relationship between hyponatremia and the short-term (within 90 days) and long-term (more than 1 year) prognosis of stroke patients was conducted.

METHODS

A computerized systematic literature search was performed before November of 2018 for relevant articles evaluating the relationship between hyponatremia and all-cause mortality risk in stroke patients. Pooled relative risk (RR) and hazard risk (HR) with 95% confidence interval (CI) were calculated using DerSimonian-Laird random-effects model. Subgroup analyses were performed according to the follow-up period, types of stroke, different controls, sample size, and sampling time.

RESULTS

A total of 12 studies with 21,973 patients were identified. Compared to the nonhyponatremia patients, hyponatremia was associated with a higher risk of all-cause mortality in short-term (RR 1.61, 95% CI 1.33-1.96; HR 1.78 95% CI 1.19-2.75) and long-term follow-up (RR 1.77, 95% CI 1.27-2.47; HR 2.23,95% CI 1.30-3.82). Subgroups analysis showed the similar results in most subgroups.

CONCLUSIONS

This meta-analysis concludes that hyponatremia has a significant prognostic value for short- and long-term prognosis to stroke patients.

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.

Frequency, determinants, and effects of early seizures after thrombolysis for acute ischemic stroke: The ENCHANTED trial

Background

Seizures after ischemic stroke have not been well-studied. We aim to determine the frequency, determinants, and significance of early seizures after thrombolysis for acute ischemic stroke.

Methods

Data are from the Enhanced Control of Hypertension and Thrombolysis Stroke Study (ENCHANTED), an international, multicenter, randomized controlled trial where patients with acute ischemic stroke were randomized to low-dose (0.6 mg/kg) or standard-dose (0.9 mg/kg) IV alteplase. The protocol prespecified prospective data collection on in-hospital seizures over 7 days postrandomization. Logistic regression models were used to determine variables associated with seizures and their significance on poor outcomes of death or disability (modified Rankin scale scores 3-6), symptomatic intracerebral hemorrhage (sICH), and European Quality of Life 5-Dimensions questionnaire [EQ-5D] over 90 days.

Results

Data were available for 3,139 acute ischemic stroke participants, of whom 42 (1.3%) had seizures at a median 22.7 hours after the onset of symptoms. Baseline variables associated with seizures were male sex (odds ratio [OR] 2.19, 95% confidence interval [CI] 1.07-4.50), severe neurologic impairment (NIH Stroke Scale score ≥10; OR 2.16, 95% CI 1.06-4.40), and fever (OR 4.55, 95% CI 2.37-8.71). Seizures independently predicted poor recovery: death or major disability (OR 2.88, 95% CI 1.28-6.47), unfavorable ordinal shift of mRS scores (OR 1.94, 95% CI 1.10-3.39), and lower than median EQ-5D health utility index score (OR 3.50, 95% CI 1.37-8.91). There was no association of seizures with sICH in adjusted analysis.

Conclusions

In thrombolysis-treated patients with acute ischemic stroke, seizures are uncommon, occur early, and predict poor recovery.

Clinicaltrialsgov identifier

NCT01422616.

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.

Post-stroke epilepsy

Post-stroke epilepsy (PSE) is a common complication after stroke, yet treatment options remain limited. While many physicians prescribe antiepileptic drugs (AED) for secondary prevention of PSE, it is unclear which treatments are most effective in the prevention of recurrence of symptoms, or whether such therapy is needed for primary prevention. This review discusses the current understanding of epidemiology, diagnoses, mechanisms, risk factors, and treatments of PSE.

The prognosis of acute symptomatic seizures after ischaemic stroke

OBJECTIVE

Acute symptomatic seizure (AS) after ischaemic stroke is defined as a seizure occurring ≤7 days of the stroke. There remains a lack of information on the prognosis of AS after ischaemic stroke and how it should be treated.

METHODS

We prospectively recruited patients after their incidents of ischaemic stroke from a population-based stroke registry. Stroke aetiology was defined according to Trial-of-ORG-10172 in acute-stroke treatment (TOAST). Patients were examined for any transient complete-occlusion with recanalisation (TCOR) and haemorrhagic transformation. The seizure outcomes were (1) acute clustering of seizures ≤7 days, (2) seizure recurrence associated with stroke recurrence beyond the 7-day period and (3) unprovoked seizure (US) >7 days.

RESULTS

104 patients (mean age 65 years/55% female) with AS after ischaemic stroke were identified (mean follow-up 6.17 years). Comparison of the group of patients with AS and those without seizures showed that patients with AS had significantly less large-vessel and small-vessel disease but more cardioembolisms (p<0.05) and a higher proportion of TCOR (p<0.01), multiple territory infarcts (p=0.007) and haemorrhagic transformations (p<0.01). Using Kaplan-Meier statistics, the risk of acute clustering of seizures ≤7 days was 22%, with a statistical trend for TCOR as a predictive factor (p=0.06). The risk of seizure recurrence associated with worsening/recurrence of stroke beyond 7 days was 13.5% at 2 years, 16.4% at 4 years and 18% at 8 years. Presence of >2 cardiovascular risk factors (p<0.05) and status epilepticus (P<0.05) are predictive risk factors on Cox regression model. The risk of US was 19% at 2 years, 25% at 4 years and 28% at 8 years with epileptiform EEG as a predictive factor (p<0.05).

CONCLUSIONS

Seizure recurrence following AS after ischaemic stroke may appear as acute clustering. Afterwards, seizures may occur as often with a recurrent stroke as without one within 4.2 years. We recommend the use of antiepileptic agents for up to 4 years if the underlying stroke aetiology cannot be fully treated.

Development of epilepsy after ischaemic stroke

For about 30% of patients with epilepsy the cause is unknown. Even in patients with a known risk factor for epilepsy, such as ischaemic stroke, only a subpopulation of patients develops epilepsy. Factors that contribute to the risk for epileptogenesis in a given individual generally remain unknown. Studies in the past decade on epilepsy in patients with ischaemic stroke suggest that, in addition to the primary ischaemic injury, existing difficult-to-detect microscale changes in blood vessels and white matter present as epileptogenic pathologies. Injury severity, location and type of pathological changes, genetic factors, and pre-injury and post-injury exposure to non-genetic factors (ie, the exposome) can divide patients with ischaemic stroke into different endophenotypes with a variable risk for epileptogenesis. These data provide guidance for animal modelling of post-stroke epilepsy, and for laboratory experiments to explore with increased specificity the molecular 'mechanisms, biomarkers, and treatment targets of post-stroke epilepsy in different circumstances, with the aim of modifying epileptogenesis after ischaemic stroke in individual patients without compromising recovery.

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.

An Enhanced Model of Middle Cerebral Artery Occlusion in Nonhuman Primates Using an Endovascular Trapping Technique

BACKGROUND AND PURPOSE

Current nonhuman primate stroke models are limited by either stroke variability or survivability. A new nonhuman primate stroke model was developed by using endovascular trapping techniques to limit collateral vessels with serial MR imaging and neurologic assessments.

MATERIALS AND METHODS

Eight adult rhesus monkeys (female, 7-13 years of age) underwent MR imaging and Spetzler neurologic assessment followed by endovascular stroke induction consisting of superselective endovascular placement of surgical silk sutures into the right MCA by using a trapping technique. Two initial subjects were euthanized immediately following postocclusion MR imaging. The subsequent 6 subjects recovered and underwent follow-up MR imaging and Spetzler neurologic assessments at 48 hours, with 4 being followed to 96 hours. Stroke infarct volumes were measured, and the longitudinal Spetzler clinical neurologic scores were assessed. The brain tissues were harvested and prepared with hematoxylin-eosin staining.

RESULTS

Focal permanent cerebral ischemia was induced in the targeted right MCA territory in all subjects. The volumes of the ischemic lesions at 6, 48, and 96 hours were 3.18 ± 1.007 mL (standard error of the mean) (n = 8), 6.70 ± 1.666 mL (standard error of the mean) (n = 6), and 7.23 ± 1.371 mL (standard error of the mean) (n = 4). For the survival animals, the immediate postsurgical Spetzler grading score improved from 60.7 at 24 hours to 68.7 at 48 hours.

CONCLUSIONS

We report a trapping modification to an established endovascular suture stroke model that yielded reproducible ischemia and clinically quantifiable neurologic deficits with no strokes in nontarget areas. This technique may be useful in evaluating translational stroke and penumbral imaging research in addition to preclinical testing of neuroprotective therapies.

Hyponatremia in the neurocritical care patient: An approach based on current evidence

In the neurocritical care setting, hyponatremia is the commonest electrolyte disorder, which is associated with significant morbimortality. Cerebral salt wasting and syndrome of inappropriate antidiuretic hormone have been classically described as the 2 most frequent entities responsible of hyponatremia in neurocritical care patients. Nevertheless, to distinguish between both syndromes is usually difficult and useless as volume status is difficult to be determined, underlying pathophysiological mechanisms are still not fully understood, fluid restriction is usually contraindicated in these patients, and the first option in the therapeutic strategy is always the same: 3% hypertonic saline solution. Therefore, we definitively agree with the current concept of "cerebral salt wasting", which means that whatever is the etiology of hyponatremia, initially in neurocritical care patients the treatment will be the same: hypertonic saline solution.

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.