Post-stroke epilepsy in an ischemic stroke cohort-Incidence and diagnosis

The Association of Epileptic Seizures after Acute Ischemic Stroke with Cerebral Cortical Involvement and Electroencephalographic Changes

Background and objectives: while acute ischemic stroke is the leading cause of epilepsy in the elderly population, data about its risk factors have been conflicting. Therefore, the aim of our study is to determine the association of early and late epileptic seizures after acute ischemic stroke with cerebral cortical involvement and electroencephalographic changes. Materials and methods: a prospective cohort study in the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics Department of Neurology was conducted and enrolled 376 acute ischemic stroke patients. Data about the demographical, clinical, radiological, and encephalographic changes was gathered. Patients were followed for 1 year after stroke and assessed for late ES. Results: the incidence of ES was 4.5%, the incidence of early ES was 2.7% and the incidence of late ES was 2.4%. The occurrence of early ES increased the probability of developing late ES. There was no association between acute cerebral cortical damage and the occurrence of ES, including both early and late ES. However, interictal epileptiform discharges were associated with the occurrence of ES, including both early and late ES.

The Progress of Poststroke Seizures

A stroke is one of the most common fatal diseases of the nervous system, and the number of strokes per year has increased substantially in recent years. Epilepsy is a poststroke complication that greatly affects the prognosis of patients and reduces their quality of survival. Effective avoidance of causative factors can reduce the risk of a poststroke seizure. However, while many studies have been devoted to elucidating the pathogenesis of poststroke seizures, the literature lacks a comprehensive understanding of the pathogenic mechanism. This article briefly presents the current definition, risk factors, pathogenesis, and prognosis of poststroke seizures based on reported studies and literature reviews, aiming to enrich the available knowledge of this disease.

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.

The epidemiology of epilepsy in older adults: A narrative review by the ILAE Task Force on Epilepsy in the Elderly

In an aging world, it is important to know the burden of epilepsy affecting populations of older persons. We performed a selective review of epidemiological studies that we considered to be most informative, trying to include data from all parts of the world. We emphasized primary reports rather than review articles. We reviewed studies reporting the incidence and prevalence of epilepsy that focused on an older population as well as studies that included a wider age range if older persons were tabulated as a subgroup. There is strong evidence that persons older than approximately 60 years incur an increasing risk of both acute symptomatic seizures and epilepsy. In wealthier countries, the incidence of epilepsy increases sharply after age 60 or 65 years. This phenomenon was not always observed among reports from populations with lower socioeconomic status. This discrepancy may reflect differences in etiologies, methods of ascertainment, or distribution of ages; this is an area for more research. We identified other areas for which there are inadequate data. Incidence data are scarcer than prevalence data and are missing for large areas of the world. Prevalence is lower than would be expected from cumulative incidence, possibly because of remissions, excess mortality, or misdiagnosis of acute symptomatic seizures as epilepsy. Segmentation by age, frailty, and comorbidities is desirable, because "epilepsy in the elderly" is otherwise too broad a concept. Data are needed on rates of status epilepticus and drug-resistant epilepsy using the newer definitions. Many more data are needed from low-income populations and from developing countries. Greater awareness of the high rates of seizures among older adults should lead to more focused diagnostic efforts for individuals. Accurate data on epilepsy among older adults should drive proper allocation of treatments for individuals and resources for societies.

Rodent Models of Audiogenic Epilepsy: Genetic Aspects, Advantages, Current Problems and Perspectives

Animal models of epilepsy are of great importance in epileptology. They are used to study the mechanisms of epileptogenesis, and search for new genes and regulatory pathways involved in the development of epilepsy as well as screening new antiepileptic drugs. Today, many methods of modeling epilepsy in animals are used, including electroconvulsive, pharmacological in intact animals, and genetic, with the predisposition for spontaneous or refractory epileptic seizures. Due to the simplicity of manipulation and universality, genetic models of audiogenic epilepsy in rodents stand out among this diversity. We tried to combine data on the genetics of audiogenic epilepsy in rodents, the relevance of various models of audiogenic epilepsy to certain epileptic syndromes in humans, and the advantages of using of rodent strains predisposed to audiogenic epilepsy in current epileptology.

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.

Incidence and Antiseizure Medications of Post-stroke Epilepsy in Umbria: A Population-Based Study Using Healthcare Administrative Databases

Introduction: Post-stroke epilepsy (PSE) requires long-term treatment with antiseizure medications (ASMs). However, epidemiology of PSE and long-term compliance with ASM in this population are still unclear. Here we report, through population-level healthcare administrative data, incidence, risk factors, ASM choice, and ASM switch over long-term follow-up.

Materials and Methods: This is a population-based retrospective study using Umbria healthcare administrative database. Population consisted of all patients with acute stroke, either ischaemic or hemorrhagic, between 2013 and 2018. ICD-9-CM codes were implemented to identify people with stroke, while PSE was adjudicated according to previously validated algorithm, such as EEG and ≥1 ASM 7 days after stroke.

Results: Overall, among 11,093 incident cases of acute stroke (75.9% ischemic), 275 subjects presented PSE, for a cumulative incidence of 2.5%. Patients with PSE were younger (64 vs. 76 years), more frequently presented with hemorrhagic stroke, and had longer hospital stay (15.5 vs. 11.2 days) compared with patients without PSE. Multivariable Cox proportional hazards models confirmed that PSE associated with hemorrhagic stroke, younger age, and longer duration of hospital stay. Levetiracetam was the most prescribed ASM (55.3%), followed by valproate and oxcarbazepine. Almost 30% of patients prescribed with these ASMs switched treatment during follow-up, mostly toward non-enzyme-inducing ASMs. About 12% of patients was prescribed ASM polytherapy over follow-up.

Conclusions: Post-stroke epilepsy is associated with hemorrhagic stroke, younger age, and longer hospital stay. First ASM is switched every one in three patients, suggesting the need for treatment tailoring in line with secondary prevention.

Occult Autoimmune Background for Epilepsy-The Preliminary Study on Antibodies Against Neuronal Surface Antigens

Objective: The objective of the study was to determine the incidence of antibodies against neuronal surface antigens (NSA-ab) in patients with different types of epilepsy, in comparison with the subjects diagnosed with immune-mediated disorders. Methods: Forty patients with drug-resistant epilepsy (DRE) of unknown origin, 16 with post-stroke epilepsy, and 23 with systemic autoimmune disorders (SAD) with CNS involvement were included. NSA-ab were sought in serum using indirect immunofluorescence method. Relationships were analyzed between presence of NSA-ab and clinical presentation. Results: NSA-ab was detected in the sera from five patients: anti-DPPX in one patient, anti-AMPAR1/R2 in two, anti-LGI1 in one and, in one case, both anti-CASPR2 and DPPX IgG. Out of these five patients, three represented the SAD subgroup and two the DRE subgroup. None of the patients with post-stroke epilepsy was positive for NSA-ab. Significance: Autoimmune etiology is worth considering in patients with drug-resistant epilepsy of unknown origin. The presence of NSA-ab in patients with systemic autoimmune disorders may be caused by unspecifically enhanced autoimmune reactivity. NSA-ab seem not to be related to epilepsy resulting from ischemic brain injury.

Acupuncture as an Adjunctive Treatment for Post-stroke Epilepsy: Protocol for a Randomized Controlled Trial

Background: Acupuncture has been clinically used to treat epilepsy after stroke. However, most of the current clinical studies are observational studies, and there are few well-designed randomized controlled trials (RCTs). Hence, we designed a multicentre RCT to assess the advantages and efficacy of acupuncture for post-stroke epilepsy (PSE).

Methods/Design: This is a two-arm, parallel, participants-blinded and assessor-blinded and multicentre RCT. A total of 120 patients with PSE aged from 18 to 75 years will be randomly assigned to two groups (routine treatment plus acupuncture group and routine treatment plus sham acupuncture group) at a 1:1 ratio. The participants will perform acupuncture or sham acupuncture treatment three times a week and be ongoing 8-week treatment. The primary endpoint is the proportion of seizure-free patients. A safety profile will be established. We will record adverse events for the safety evaluation.

Discussion: The study will provide high-quality clinical evidence on the effectiveness and safety of acupuncture for treating patients with epilepsy after stroke.

Clinical Trial Registration: Chinese Clinical Trial Registry, identifier: ChiCTR2100046114.

Current advances on mechanisms and treatment of post-stroke seizures

Cerebrovascular diseases are among the most common causes of seizures in adults, especially in the elderly. With the increased incidence of stroke, the population with post-stroke seizures has grown, leading to the increased awareness of this disorder in the society. The most common seizure type after stroke is the focal seizure with or without evolution into bilateral convulsive seizures. Post-stroke seizures impair the quality of life, as well as the physical and mental health of those patients. Currently, the pathological and physical processes of post-stroke seizures are not quite clear yet. In this review, we summarize current advances in the pathogenesis, risk factors, and therapeutic targets of post-stroke seizures.

Poststroke epilepsy incidence, risk factors and treatment: German claims analysis

Objectives

To describe incidence, risk factors, and treatment of poststroke epilepsy (PSE) in Germany based on claims data.

Methods

Retrospective analysis of claims data from a German public sickness fund (AOK PLUS). Patients with acute stroke hospitalizations from January 01, 2011 and December 31, 2015 (index hospitalization) were followed for 12–72 months. Outcomes included incidence of PSE (patients with ≥2 seizure claims [during/after index hospitalization], or ≥1 seizure claim after index hospitalization), multivariate Cox‐regression analyses of time to seizure claim and death after index stroke hospitalization discharge, and antiepileptic drug (AED) treatment.

Results

Among 53 883 patients with stroke (mean follow‐up of 829.05 days [median 749]), 6054 (11.24%) had ≥1 seizure claim (mean age 73.95 years, 54.18% female). 2130 (35.18%) patients had a seizure claim during index hospitalization (indicative of acute symptomatic seizures). Estimated incidence of PSE (cases/1000 patient‐years) was 94.49 within 1 year. Risk of seizure claim following hospital discharge was higher in patients with hemorrhagic stroke (hazard ratio [HR] =1.13; p <.001) vs those with cerebral infarction. Seizure claim during index hospitalization was a risk factor for seizure claims after hospital discharge (HR =6.97; p <.001) and early death (HR =1.78; p <.001). In the first year of follow‐up, AEDs were prescribed in 73.75% of patients with seizure claims.

Conclusions

Incidence of PSE was in line with previous studies. Hemorrhagic stroke and seizure claim during index hospitalization were risk factors for seizure claims after hospital discharge. Most patients with seizure claims received AED treatment.

Risk of ischaemic stroke associated with antiepileptic drugs: a population-based case-control study in Catalonia

BACKGROUND

Cerebrovascular disorders have occurred more frequently in some Central Nervous System (CNS) disorders, such as epilepsy. Some CNS drugs have been associated with increased stroke risk. Our aim was to estimate the risk of ischaemic stroke in patients exposed to antiepileptic drugs (AED).

METHODS

Population-based matched case-control study using SIDIAP database, based in electronic health records from primary healthcare from Catalonia, Spain. Cases were those patients with a registered diagnosis of first stroke during 2009-2014. Up to 10 controls were selected for each case and matched by sex, age, and geographic area and without a prior diagnosis of stroke. We considered global drug exposure to AED, past and current exposure and exposure in monotherapy to each AED.

RESULTS

2,865 cases and 19,406 controls were exposed to AED during the study period. Global exposure to levetiracetam [(OR_adj3.3, CI95 % 2.8-4.0)], phenytoin [OR_adj1.5, CI95 % 1.2-41.9)], and valproic acid [(OR_adj 1.3, CI95 % 1.1-1.6)], showed significantly association to ischaemic stroke that was also maintained with current exposure of levetiracetam [OR_adj4.1, CI95 % 3.3-5.2)] and valproic acid [OR_adj1.4, CI95 % 1.1-1.9)]. Current levetiracetam monotherapy showed a very high risk of ischaemic stroke [(OR_adj 5.1, CI95 % 3.7-6.9)].

CONCLUSIONS

Drugs used for other conditions than epilepsy (pregabalin, gabapentin) were the most used AED and both did not show a risk. Levetiracetam shows a risk for stroke even when assessed in current monotherapy. The lack of data regarding the link with diagnosis and severity in our study makes it necessary to conduct further studies to confirm or dismiss our results, focussing on levetiracetam.