Association between seizures after ischemic stroke and stroke outcome: A systematic review and meta-analysis

The value of electroencephalography features in the prognostic evaluation of large hemispheric infarction patients at different time intervals

BACKGROUND

Large Hemispheric Infarction (LHI) is a devastating disease with high mortality. This study aimed to use electroencephalography (EEG) to evaluate the death risk of LHI patients and identify suitable evaluation time.

METHODS

This study retrospectively collected clinical and EEG data from 73 LHI patients, dividing them into death and survival group at discharge. EEG data was classified as 1-5 days and 6-14 days after onset according to the time intervals of cerebral edema. Regression and receiver operator characteristic curve (ROC) analysis were applied to explore the impact of temporal changes in various EEG and clinical features on death.

RESULTS

The areas under ROC curve (AUC) of death prediction for non-α frequency on non-infarct side at 6-14 days after onset was significantly higher than that at 1-5 days (p = 0.004). And there was no significant difference between the AUC of seizure activity for death prediction at 1-5 days and 6-14 days (p = 0.418). Multivariate regression analysis revealed that non-α frequency on non-infarct side and seizure activity at 6-14 days after onset were the independent risk factors for the death of LHI patients. Additionally, above two EEG features significantly improved the death predictive efficacy of clinical features in LHI patients with the integrated discrimination improvement index (IDI) of 0.174 (p = 0.015) and the net reclassification improvement (NRI) of 1.314 (p<0.001).

CONCLUSIONS

Non-α frequency on non-infarct side and seizure activity were reliable indicators for death prediction. 6-14 days after onset was the better time window for death evaluation of LHI patients through EEG.

Predictors of the unfavorable outcomes in acute ischemic stroke patients treated with alteplase, a multi-center randomized trial

Worldwide, stroke is a leading cause of long-term disability in adults. Alteplase is the only approved treatment for acute ischemic stroke (AIS) and results in an improvement in a third of treated patients. We evaluated the post-stroke unfavourable outcome predictors in alteplase-treated patients from Egypt and Saudi Arabia. We assessed the effect of different risk factors on AIS outcomes after alteplase in Egypt and Saudi Arabia. Our study included 592 AIS alteplase-treated patients. The relationship between risk factors, clinical presentation, and imaging features was evaluated to predict factors associated with poor outcomes. An mRS score of three or more was used to define poor outcomes. Poor outcome was seen in 136 patients (23%), and Patients with unfavourable effects had significantly higher admission hyperglycaemia, a higher percentage of diabetes mellitus, cardioembolic stroke, and a lower percentage of small vessel stroke. Patients with higher baseline NIHSS score (OR 1.39; 95% CI 1.12-1.71; P = 0.003), admission hyperglycaemia (OR 13.12; 95% CI 3.37-51.1; P < 0.001), and post-alteplase intracerebral haemorrhage (OR 7.41; 95% CI 1.69-32.43; P = 0.008) independently predicted unfavourable outcomes at three months. In AIS patients treated with alteplase, similar to reports from other regions, in patients from Egypt and Saudi Arabia also reveal that higher NIHSS, higher serum blood sugar, and post-alteplase intracerebral haemorrhage were the predictors of unfavourable outcomes three months after ischemic stroke.Trial registration: (clinicaltrials.gov NCT06058884), retrospectively registered on 28/09/2023.

Study protocol for a phase II randomised, double-blind, placebo-controlled trial of perampanel as an antiepileptogenic treatment following acute stroke

INTRODUCTION

Stroke is a common cause of epilepsy that may be mediated via glutamate dysregulation. There is currently no evidence to support the use of antiseizure medications as primary prevention against poststroke epilepsy. Perampanel has a unique antiglutamatergic mechanism of action and may have antiepileptogenic properties. This study aims to evaluate the efficacy and safety of perampanel as an antiepileptogenic treatment in patients at high risk of poststroke epilepsy.

METHODS AND ANALYSIS

Up to 328 patients with cortical ischaemic stroke or lobar haemorrhage will be enrolled, and receive their first treatment within 7 days of stroke onset. Patients will be randomised (1:1) to receive perampanel (titrated to 6 mg daily over 4 weeks) or matching placebo, stratified by stroke subtype (ischaemic or haemorrhagic). Treatment will be continued for 12 weeks after titration. 7T MRI will be performed at baseline for quantification of cerebral glutamate by magnetic resonance spectroscopy and glutamate chemical exchange saturation transfer imaging. Blood will be collected for measurement of plasma glutamate levels. Participants will be followed up for 52 weeks after randomisation.The primary study outcome will be the proportion of participants in each group free of late (more than 7 days after stroke onset) poststroke seizures by the end of the 12-month study period, analysed by Fisher's exact test. Secondary outcomes will include time to first seizure, time to treatment withdrawal and 3-month modified Rankin Scale score. Quality of life, cognitive function, mood and adverse events will be assessed by standardised questionnaires. Exploratory outcomes will include correlation between cerebral and plasma glutamate concentration and stroke and seizure outcomes.

ETHICS AND DISSEMINATION

This study was approved by the Alfred Health Human Research Ethics Committee (HREC No 44366, Reference 287/18).

TRIAL REGISTRATION NUMBER

ACTRN12618001984280; Pre-results.

Systematic prolonged video-electroencephalograms identify electrographic seizures in 5% of acute stroke patients with aphasia

In stroke units, diagnosing seizures may be difficult, especially in aphasic patients. We discuss herein our systematic 4-hour video EEG monitoring of 61 patients with aphasia within the first 72hours after the onset of ischaemic stroke. Five electrographic seizures were identified in 3 patients, with no clinical signs apparent on the video and no symptoms reported by patients. We did not record status epilepticus nor generalized seizure. Comparative analyses disclosed a higher risk of early seizures in patients with haemorrhagic transformation. Video EEG monitoring detected electrographic seizures in 5% of stroke patients with aphasia. This monitoring could be useful for selected patients, especially those with haemorrhagic transformation.

Statin use and the risk of post-stroke seizures: A meta-analysis

PURPOSE

The magnitude of association between statin use and post-stroke seizures (PSS) risk remains unclear. Therefore, the aim of this meta-analysis was to evaluate this issue.

METHODS

We systematically searched electronic libraries, including Medline, Embase, and Cochrane databases, for relevant clinical studies. The main outcome was the risk of early PSS and the risk of post-stroke epilepsy (PSE). The pooled relative risks (RRs) and the corresponding 95% confidence intervals (CIs) were used to calculate the association between statin treatment and risks of early PSS and PSE.

RESULTS

A total of 7 articles met our inclusion criteria and were included. For early PSS risk, statin use was associated with a lower risk of early PSS (RR 0.36, 95% CI 0.25-0.53; p < 0.001). Subgroup analyses based on the prescribing timing of statins showed that pre-stroke statin use was not associated with the risk of early PSS; post-stroke statin use was associated with a lower risk of early PSS (RR 0.37, 95% CI 0.25-0.54; p < 0.001). For PSE risk, statin use was associated with a lower risk of PSE (RR 0.62, 95% CI 0.42-0.92; p = 0.017). Further subgroup analyses based on the prescribing timing of statins indicated that pre-stroke statin use was not associated with the risk of PSE; post-stroke statin use was associated with a lower risk of PSE (RR 0.59, 95% CI 0.49-0.70; p < 0.001).

CONCLUSIONS

Statin treatment, especially the post-statin treatment, was associated with lower risks of early PSS and PSE.

Can respiratory muscle training therapy effectively manage obstructive sleep apnea syndrome after stroke?: A protocol of systematic review and meta-analysis

BACKGROUND

This study will explore the effectiveness and safety of respiratory muscle training therapy (RMTT) for the treatment of patients with obstructive sleep apnea syndrome (OSAS) after stroke.

METHODS

In this study, we will systematically and comprehensively search Cochrane Library, PubMed, EMBASE, WANGFANG, VIP, Chinese Biomedical Literature Database, and China National Knowledge Infrastructure for relevant literature from their inception to March 1, 2020 without any limitations to language and publication status. We will consider any randomized controlled trials focusing on the effectiveness and safety of RMTT for the treatment of patients with OSAS after stroke. The study quality will be checked using Cochrane risk of bias tool, and statistical analysis will be performed utilizing RevMan 5.3 software.

RESULTS

This study will summarize and synthesize the current evidence of RMTT for the treatment of patients with OSAS following stroke.

CONCLUSION

The findings of this study will assess the present evidence for the benefits and harms of RMTT for treating OSAS after stroke, and will inform clinical practice and future research.

PROSPERO REGISTRATION NUMBER

PROSPERO CRD42020170355.

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.

Role of cerebral glutamate in post-stroke epileptogenesis

Stroke is one of the most important causes of acquired epilepsy in the adult population. While factors such as cortical involvement and haemorrhage have been associated with increased seizure risk, the mechanisms underlying the development of epilepsy after stroke remain unclear. One hypothesised mechanism is an excitotoxic effect of abnormal glutamate release following a stroke. Cerebral extracellular glutamate levels are known to rise in the setting of acute stroke, and numerous studies have implicated glutamate in the pathogenesis of seizures and epilepsy, both through direct measurement of glutamate from the epileptic brain and by analysis of receptors and transporters central to glutamate homeostasis. While experimental evidence suggests the cellular injury induced by glutamate exposure may lead to development of an epileptic phenotype, there is little direct data linking the rise in glutamate during stroke with the later development of epilepsy. Clinical research in this field has been hampered by the lack of non-invasive methods to measure cerebral glutamate. However, with the increasing availability of 7T MRI technology, Magnetic Resonance Spectroscopy is able to better resolve glutamate from other chemical species at this field strength, and Glutamate Chemical Exchange Saturation Transfer (GluCEST) imaging has been applied to localise epileptic foci in non-lesional focal epilepsy. This review outlines the evidence implicating a pivotal role for cerebral glutamate in the development of post-stroke epilepsy, and exploring the role of MRI in studying glutamate as a biomarker and therefore its suitability as a molecular target for anti-epileptogenic therapies. We hypothesise that the rise in glutamate levels in the setting of acute stroke is a clinically relevant biomarker for the development of post-stroke epilepsy.

Role of microRNA-155 in modifying neuroinflammation and γ-aminobutyric acid transporters in specific central regions after post-ischaemic seizures

In the central nervous system, interleukin (IL)‐1β, IL‐6 and tumour necrosis factor (TNF)‐α have a regulatory role in pathophysiological processes of epilepsy. In addition, γ‐aminobutyric acid (GABA) transporter type 1 and type 3 (GAT‐1 and GAT‐3) modulate the levels of extracellular GABA in involvement in the neuroinflammation on epileptogenesis. Thus, in the current report we examined the effects of inhibiting microRNA‐155 (miR‐155) on the levels of IL‐1β, IL‐6 and TNF‐α, and expression of GAT‐1 and GAT‐3 in the parietal cortex, hippocampus and amygdala of rats with nonconvulsive seizure (NCS) following cerebral ischaemia. Real time RT‐PCR, ELISA and Western blot analysis were used to examine the miR‐155, proinflammatory cytokines (PICs) and GAT‐1/GAT‐3 respectively. With induction of NCS, the levels of miR‐155 were amplified in the parietal cortex, hippocampus and amygdala and this was accompanied with increases of IL‐1β, IL‐6 and TNF‐α. In those central areas, expression of GAT‐1 and GAT‐3 was upregulated; and GABA was reduced in rats following NCS. Intracerebroventricular infusion of miR‐155 inhibitor attenuated the elevation of PICs, amplification of GAT‐1 and GAT‐3 and impairment of GABA. Furthermore, inhibition of miR‐155 decreased the number of NCS events following cerebral ischaemia. Inhibition of miR‐155 further improved post‐ischaemia‐evoked NCS by altering neuroinflammation‐GABA signal pathways in the parietal cortex, hippocampus and amygdala. Results suggest the role of miR‐155 in regulating post‐ischaemic seizures via PICs‐GABA mechanisms.

Poststroke seizure: optimising its management

Seizure after stroke or poststroke seizure (PSS) is a common and very important complication of stroke. It can be divided into early seizure and late seizure, depending on seizure onset time after the stroke. It has been reported that ischaemic and haemorrhagic stroke accounts for about 11% of all adult epilepsy cases and 45% of epilepsy cases over 60 years of age. However, there are no reliable guidelines in clinical practice regarding most of the fundamental issues of PSS management. In recent years there has been an increased interest in the study of PSS which may give clinical practitioners a better picture of how to optimise PSS management. Studies have indicated two peaks in PSS occurrence—the first day and 6–12 months after a stroke. Haemorrhagic stroke, cortical involvement, severity of initial neurological deficit, younger patients (<65 years of age), family history of seizures and certain genetic factors carry a higher risk of PSS. The use of continuous electroencephalogram has demonstrated significant benefits in capturing interictal or ictal abnormalities, especially in cases of non-convulsive seizures and non-convulsive status epilepticus. Current available data indicated that there was no significant difference in antiepileptic efficacy among most of the antiepileptic drugs (AEDs) in PSS. Levetiracetam and lamotrigine are the most studied newer generation AEDs and have the best drug tolerance. The purpose of this review is to summarise the recent advances in PSS research and focus on the most important practice issues of PSS management.

Stroke in Pediatric Bacterial Meningitis: Population-Based Epidemiology

BACKGROUND

Bacterial meningitis is a severe infection of the nervous system with a high complication rate including stroke. The purpose of this study is to assess the incidence, risk factors, patterns, and outcomes in pediatric meningitis complicated by stroke.

METHODS

The study design was a population-based, 10-year retrospective (2002 to 2012) cohort study set in Southern Alberta, Canada. The inclusion criteria were: (1) age from newborn to 18 years, (2) brain magnetic resonance imaging (MRI) including diffusion-weighted imaging during admission, and (3) laboratory confirmed acute bacterial meningitis. The main outcomes were demographics, clinical presentations, risk factors, laboratory findings, radiographic findings, and neurological outcomes.

FINDINGS

Forty-three patients had confirmed bacterial meningitis and diffusion MRI (9 neonates (21%), 89% male; 22 infants aged one month to one year (51%), 50% male; and 12 children older than one year (28%), 58% male, median age four years (interquartile range 7.9 years). Ischemic stroke was confirmed in 16/43 (37%), often multifocal (94%). Patients with stroke were significantly more likely to have seizures (P = 0.025), otitis media (P = 0.029), and multiple presentations to hospital (P = 0.013). Mortality was 25% in children with stroke compared with 4% in those without (P = 0.067). Survivors with stroke were more likely to have neurological deficits at follow-up (69% versus 26%, P = 0.019).

CONCLUSIONS

More than one-third of children with acute bacterial meningitis and clinically indicated MRI had ischemic stroke. Stroke was associated with clinical factors including duration of illness, seizures, and causative organisms. Stroke was associated with higher mortality and morbidity, warranting consideration of increased MRI screening and new approaches to treatment.

Epilepsy after stroke: Definitions, problems and a practical approach for clinicians

Stroke, whether ischemic or hemorrhagic, is the main etiology of epilepsy in the elderly. However, incidences and outcomes differ according to stroke subtype and delay of onset following the stroke. While the medical literature is extensive, it is not always consistent, and many questions still remain regarding risk factors and management of vascular epilepsy. Thus, the present report here is an overview of the clinical aspects of vascular epilepsy using a practical approach that integrates data from meta-analyses and the more recently published expert recommendations.

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.

Contributions of the Hippocampal CA3 Circuitry to Acute Seizures and Hyperexcitability Responses in Mouse Models of Brain Ischemia

The hippocampal circuitry is widely recognized as susceptible to ischemic injury and seizure generation. However, hippocampal contribution to acute non-convulsive seizures (NCS) in models involving middle cerebral artery occlusion (MCAO) remains to be determined. To address this, we occluded the middle cerebral artery in adult C57 black mice and monitored electroencephalographic (EEG) discharges from hippocampal and neocortical areas. Electrographic discharges in the absence of convulsive motor behaviors were observed within 90 min following occlusion of the middle cerebral artery. Hippocampal discharges were more robust than corresponding cortical discharges in all seizure events examined, and hippocampal discharges alone or with minimal cortical involvement were also observed in some seizure events. Seizure development was associated with ipsilateral hippocampal injuries as determined by subsequent histological examinations. We also introduced hypoxia-hypoglycemia episodes in mouse brain slices and examined regional hyperexcitable responses ex vivo. Extracellular recordings showed that the hippocampal CA3 region had a greater propensity for exhibiting single/multiunit activities or epileptiform field potentials following hypoxic-hypoglycemic (HH) episodes compared to the CA1, dentate gyrus, entorhinal cortical (EC) or neocortical regions. Whole-cell recordings revealed that CA3 pyramidal neurons exhibited excessive excitatory postsynaptic currents, attenuated inhibitory postsynaptic currents and intermittent or repetitive spikes in response to HH challenge. Together, these observations suggest that hippocampal discharges, possibly as a result of CA3 circuitry hyperexcitability, are a major component of acute NCS in a mouse model of MCAO.

Population-Based Assessment of the Long-Term Risk of Seizures in Survivors of Stroke

BACKGROUND AND PURPOSE

We sought to determine the long-term risk of seizures after stroke according to age, sex, race, and stroke subtype.

METHODS

We performed a retrospective cohort study using administrative claims from 2 complementary patient data sets. First, we analyzed data from all emergency department visits and hospitalizations in California, Florida, and New York from 2005 to 2013. Second, we evaluated inpatient and outpatient claims from a nationally representative 5% random sample of Medicare beneficiaries. Our cohort consisted of all adults at the time of acute stroke hospitalization without a prior history of seizures. Our outcome was seizure occurring after hospital discharge for stroke. Poisson regression and demographic data were used to calculate age-, sex-, and race-standardized incidence rate ratios (IRR).

RESULTS

Among 777 276 patients in the multistate cohort, the annual incidence of seizures was 1.68% (95% confidence interval [CI], 1.67%-1.70%) after stroke versus 0.15% (95% CI, 0.15%-0.15%) among the general population (IRR, 7.3; 95% CI, 7.3-7.4). By 8 years, the cumulative rate of any emergency department visit or hospitalization for seizure was 9.27% (95% CI, 9.16%-9.38%) after stroke versus 1.21% (95% CI, 1.21%-1.22%) in the general population. Stroke was more strongly associated with a subsequent seizure among patients <65 years of age (IRR, 12.0; 95% CI, 11.9-12.2) than in patients ≥65 years of age (IRR, 5.5; 95% CI, 5.4-5.5) and in the multistate analysis, the association between stroke and seizure was stronger among nonwhite patients (IRR, 11.0; 95% CI, 10.8-11.2) than among white patients (IRR, 7.3; 95% CI, 7.2-7.4). Risks were especially elevated after intracerebral hemorrhage (IRR, 13.3; 95% CI, 13.0-13.6) and subarachnoid hemorrhage (IRR, 13.2; 95% CI, 12.8-13.7). Our study of Medicare beneficiaries confirmed these findings.

CONCLUSIONS

Almost 10% of patients with stroke will develop seizures within a decade. Hemorrhagic stroke, nonwhite race, and younger age seem to confer the greatest risk of developing seizures.

Seizures After Intracerebral Hemorrhage: Incidence, Risk Factors, and Impact on Mortality and Morbidity

OBJECTIVE

Spontaneous intracerebral hemorrhage (ICH) is one of the most frequent causes of epilepsy in the United States. However, reported risk factors for seizure after are inconsistent, and their impact on inpatient morbidity and mortality is unclear. We aimed to study the incidence, risk factors, and impact of seizures after ICH in a nationwide patient sample.

METHODS

We queried the Nationwide Inpatient Sample for patients admitted to the hospital with a primary diagnosis of ICH between the years 1999 and 2011. Patients were subsequently dichotomized into groups of those with a diagnosis consistent with seizure and those without. Multivariate logistic regression was used to assess risk factors for seizure in this patient sample, and the association between seizures and mortality and morbidity. Logistic regression was then used for trend analysis of incidence of seizure diagnoses over time.

RESULTS

We identified 220,075 patients admitted with a primary diagnosis of ICH. Of these, 11.87% had a diagnosis consistent with seizure. Factors associated with increased risk of seizure after ICH included higher categorical van Walraven score, encephalopathy, alcohol abuse, solid tumor, and prior stroke. Seizure was independently associated with decreased odds of morbidity (odds ratio [OR], 0.89; 95% confidence interval [CI], 0.86-0.92) and mortality (OR, 0.75; 95% CI, 0.72-0.77) in multivariate models controlling for existing comorbidities.

CONCLUSIONS

Seizures after were associated with decreased mortality and morbidity despite attempts to correct for existing comorbidities. Continuous monitoring of these patients for seizures may not be necessary in all circumstances, despite their frequency.