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

Increased risk of epilepsy after transient global amnesia: A population-based study in South Korea

PURPOSE

This study aimed to investigate the risk of epilepsy after transient global amnesia (TGA).

METHODS

Study population was recruited using the International Classification of Diseases codes from the Korean National Health Insurance Service database between 2002 and 2020. The incidence of epilepsy was compared between the TGA (n=12,390) and non-TGA (n=33,868) groups, determined using 1:3 propensity score matching. Using Cox proportional hazard regression model, we obtained adjusted hazard ratios (aHRs) and 95% confidence intervals (CIs) for incident epilepsy in the TGA compared with non-TGA group. Logistic regression was performed to examine the independent variables determining incident epilepsy in the TGA group, and adjusted odds ratios (aORs) and 95% CIs were calculated.

RESULTS

The TGA group had a significantly higher cumulative incidence of epilepsy than controls (p <0.001, log-rank test). TGA was significantly associated with incident epilepsy in the Cox model (adjusted HR 1.46, 95% CI 1.36-1.56). The adjusted logistic regression showed that age (per 1 year, aOR 1.02, 95% CI 1.01-1.02), female sex (aOR 0.68, 95% CI 0.60-0.77), hypertension (aOR 1.14, 95% CI 1.00-1.30), diabetes (aOR 1.26, 95% CI 1.10-1.44), stroke (aOR 1.22, 95% CI 1.06-1.40), depression (aOR 1.44, 95% CI 1.22-1.69), anxiety (aOR 1.31, 95% CI 1.14-1.51), alcohol-related disease (aOR 1.96, 95% CI 1.38-2.78), low income (aOR 1.18, 95% CI 1.02-1.36) and rural residence (aOR 1.20, 95% CI 1.02-1.42) were associated with incident epilepsy.

CONCLUSIONS

Our results suggest a longitudinal association of TGA with incident epilepsy.

Efficacy of perampanel by etiology in Japanese patients with epilepsy-subpopulation analysis of a prospective post-marketing observational study

OBJECTIVE

To examine the efficacy and safety of perampanel (PER) in patients with post-stroke epilepsy (PSE), brain tumor-related epilepsy (BTRE), and post-traumatic epilepsy (PTE) using Japanese real-world data.

METHODS

The prospective post-marketing observational study included patients with focal seizures with or without focal to bilateral tonic-clonic seizures who received PER combination therapy. The observation period was 24 or 52 weeks after the initial PER administration. The safety and efficacy analysis included 3716 and 3272 patients, respectively. This post hoc analysis examined responder rate (50% reduction in seizure frequency), seizure-free rate (proportion of patients who achieved seizure-free), and safety in patients included in the post-marketing study who had PSE, BTRE, and PTE in the 4 weeks prior to the last observation.

RESULTS

Overall, 402, 272, and 186 patients were included in the PSE, BTRE, and PTE subpopulations, and 2867 controls in the "Other" population (etiologies other than PSE, BTRE, or PTE). Mean modal dose (the most frequently administered dose) values at 52 weeks were 3.38, 3.36, 3.64, and 4.04 mg/day for PSE, BTRE, PTE, and "Other," respectively; PER retention rates were 56.2%, 54.0%, 52.6%, and 59.7%, respectively. Responder rates (% [95% confidence interval]) were 82% (76.3%-86.5%), 78% (70.8%-83.7%), 67% (56.8%-75.6%), and 50% (47.9%-52.7%) for PSE, BTRE, PTE, and "Other," respectively, and seizure-free rates were 71% (64.5%-76.5%), 62% (54.1%-69.0%), 50% (40.6%-60.4%), and 28% (25.8%-30.1%), respectively. Adverse drug reactions tended to occur less frequently in the PSE (14.7%), BTRE (16.5%), and PTE (16.7%) subpopulations than in the "Other" population (26.3%).

SIGNIFICANCE

In real-world clinical conditions, efficacy and tolerability for PER combination therapy were observed at low PER doses for the PSE, BTRE, and PTE subpopulations.

PLAIN LANGUAGE SUMMARY

To find out how well the medication perampanel works and whether it is safe for people who have epilepsy after having had a stroke, brain tumor, or head injury, we used information from real-life medical situations in Japan. We looked at the data of about 3700 Japanese patients with epilepsy who were treated with perampanel. We found that perampanel was used at lower doses and better at controlling seizures, and had fewer side effects for patients with epilepsy caused by these etiologies than the control group.

GPR56: A potential therapeutic target for neurological and psychiatric disorders

GPR56, also known as GPR56/ADGRG1, is a member of the ADGRG subgroup belonging to adhesion G protein-coupled receptors (aGPCRs). aGPCRs are the second largest subfamily of the GPCR superfamily, which is the largest family of membrane protein receptors in the human genome. Studies in recent years have demonstrated that GPR56 is integral to the normal development of the brain and functions as an important player in cortical development, suggesting that GPR56 is involved in many physiological processes. Indeed, aberrant expression of GPR56 has been implicated in multiple neurological and psychiatric disorders, including bilateral frontoparietal polymicrogyria (BFPP), depression and epilepsy. In a recent study, it was found that upregulated expression of GPR56 reduced depressive-like behaviours in an animal model of depression, indicating that GPR56 plays an important role in the antidepressant response. Given the link of GPR56 with the antidepressant response, the function of GPR56 has become a focus of research. Although GPR56 may be a potential target for the development of antidepressants, the underlying molecular mechanisms remain largely unknown. Therefore, in this review, we will summarize the latest findings of GPR56 function in neurological and psychiatric disorders (depression, epilepsy, autism, and BFPP) and emphasize the mechanisms of GPR56 in activation and signalling in those conditions. After reviewing several studies, attributing to its significant biological functions and exceptionally long extracellular N-terminus that interacts with multiple ligands, we draw a conclusion that GPR56 may serve as an important drug target for neuropsychological diseases.

Ironing out the Links: Ferroptosis in epilepsy and SUDEP

Iron is a crucial element for almost all organisms because it plays a vital role in oxygen transport, enzymatic processes, and energy generation due to its electron transfer capabilities. However, its dysregulation can lead to a form of programmed cell death known as ferroptosis, which is characterized by cellular iron accumulation, reactive oxygen species (ROS) production, and unrestricted lipid peroxidation. Both iron and ferroptosis have been identified as key players in the pathogenesis of various neurodegenerative diseases. While in epilepsy this phenomenon remains relatively understudied, seizures can be considered hypoxic-ischemic episodes resulting in increased ROS production, lipid peroxidation, membrane disorganization, and cell death. All of this is accompanied by elevated intracellular free Fe2+ concentration and hemosiderin precipitation, as existing reports suggest a significant accumulation of iron in the brain and heart associated with epilepsy. Generalized tonic-clonic seizures (GTCS), a primary risk factor for Sudden Unexpected Death in Epilepsy (SUDEP), not only have an impact on the brain but also lead to cardiogenic dysfunctions associated with "Iron Overload and Cardiomyopathy" (IOC) and "Epileptic heart" characterized by electrical and mechanical dysfunction and a high risk of malignant bradycardia. In line with this phenomenon, studies conducted by our research group have demonstrated that recurrent seizures induce hypoxia in cardiomyocytes, resulting in P-glycoprotein (P-gp) overexpression, prolonged Q-T interval, severe bradycardia, and hemosiderin precipitation, correlating with an elevated spontaneous death ratio. In this article, we explore the intricate connections among ferroptosis, epilepsy, and SUDEP. By synthesizing current knowledge and drawing insights from recent publications, this study provides a comprehensive understanding of the molecular underpinnings. Furthermore, this review offers insights into potential therapeutic avenues and outlines future research directions.

Late onset epilepsy and stroke: Diagnosis, pathogenesis and prevention

The association of stroke and late-onset epilepsy (LOE) is discussed with special regard to its diagnosis, pathogenesis, and prevention. In addition to epidemiological data, including those from different age groups, the mechanisms for the development of acute symptomatic and remote symptomatic seizures are reviewed. The risk factors associated with seizures and post-stroke epilepsy (PSE) are considered, along with the methodological limitations of the study. For future research, the distinction between acute and remote symptomatic seizure before or after seven days from stroke onset should be reviewed because different acute symptomatic seizures (ASSs) themselves can entail a variable PSE risk. The definition of LOE by age is hitherto inconsistent. Comparing adult lifespan epochs, it is evident that stroke and seizures exhibit similar prevalence profiles. Young adulthood, old adulthood, and elderly epochs may be relevant for the differentiation of LOE subtype by age, vascular comorbidity, and other characteristics. A step-scheme strategy as a possible contribution to cerebrovascular prevention approaches is proposed.

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.

Inhibition of Neuron-Restrictive Silencing Factor (REST/NRSF) Chromatin Binding Attenuates Epileptogenesis

The mechanisms by which brain insults lead to subsequent epilepsy remain unclear. Insults including trauma, stroke, infections, and long seizures (status epilepticus, SE) increase the nuclear expression and chromatin binding of the neuron-restrictive silencing factor/RE-1 silencing transcription factor (NRSF/REST). REST/NRSF orchestrates major disruption of the expression of key neuronal genes, including ion channels and neurotransmitter receptors, potentially contributing to epileptogenesis. Accordingly, transient interference with REST/NRSF chromatin binding after an epilepsy-provoking SE suppressed spontaneous seizures for the 12 d duration of a prior study. However, whether the onset of epileptogenesis was suppressed or only delayed has remained unresolved. The current experiments determined if transient interference with REST/NRSF chromatin binding prevented epileptogenesis enduringly or, alternatively, slowed epilepsy onset. Epileptogenesis was elicited in adult male rats via systemic kainic acid-induced SE (KA-SE). We then determined if decoy, NRSF-binding-motif oligodeoxynucleotides (NRSE-ODNs), given twice following KA-SE (1) prevented REST/NRSF binding to chromatin, using chromatin immunoprecipitation, or (2) prevented the onset of spontaneous seizures, measured with chronic digital video-electroencephalogram. Blocking NRSF function transiently after KA-SE significantly lengthened the latent period to a first spontaneous seizure. Whereas this intervention did not influence the duration and severity of spontaneous seizures, total seizure number and seizure burden were lower in the NRSE-ODN compared with scrambled-ODN cohorts. Transient interference with REST/NRSF function after KA-SE delays and moderately attenuates insult-related hippocampal epilepsy, but does not abolish it. Thus, the anticonvulsant and antiepileptogenic actions of NRSF are but one of the multifactorial mechanisms generating epilepsy in the adult brain.

Clinical approaches for poststroke seizure: a review

Poststroke seizure is a potential complication of stroke, which is the most frequent acute symptomatic seizure in adults. Patients with stroke may present with an abnormal or aggressive behavior accompanied by altered mental status and symptoms, such as hemiparesis, dysarthria, and sensory deficits. Although stroke manifestations that mimic seizures are rare, diagnosing poststroke seizures can be challenging when accompanied with negative postictal symptoms. Differential diagnoses of poststroke seizures include movement disorders, syncope, and functional (nonepileptic) seizures, which may present with symptoms similar to seizures. Furthermore, it is important to determine whether poststroke seizures occur early or late. Seizures occurring within and after 7 d of stroke onset were classified as early and late seizures, respectively. Early seizures have the same clinical course as acute symptomatic seizures; they rarely recur or require long-term antiseizure medication. Conversely, late seizures are associated with a risk of recurrence similar to that of unprovoked seizures in a patient with a focal lesion, thereby requiring long-term administration of antiseizure medication. After diagnosis, concerns regarding treatment strategies, treatment duration, and administration of primary and secondary prophylaxis often arise. Antiseizure medication decisions for the initiation of short-term primary and long-term secondary seizure prophylaxis should be considered for patients with stroke. Antiseizure drugs such as lamotrigine, carbamazepine, lacosamide, levetiracetam, phenytoin, and valproate may be administered. Poststroke seizures should be diagnosed systematically through history with differential diagnosis; in addition, classifying them as early or late seizures can help to determine treatment strategies.

Risk Factors and Temporal Patterns of Poststroke Epilepsy across Stroke Subtypes: Insights from a Nationwide Cohort Study in Korea

INTRODUCTION

We aimed to investigate the risk factors associated with poststroke epilepsy (PSE) among patients with different subtypes of stroke, focusing on age-related risk and time-varying effects of stroke subtypes on PSE development.

METHODS

A retrospective, nationwide, population-based cohort study was conducted using Korean National Health Insurance Service-National Sample Cohort data. Patients hospitalized with newly diagnosed stroke from 2005 to 2015 were included and followed up for up to 10 years. The primary outcome was the development of PSE, defined as having a diagnostic code and a prescription for anti-seizure medication. Multivariable Cox proportional hazard models were used to estimate PSE hazard ratios (HRs), and time-varying effects were also assessed.

RESULTS

A total of 8,305 patients with ischemic stroke, 1,563 with intracerebral hemorrhage (ICH), and 931 with subarachnoid hemorrhage (SAH) were included. During 10 years of follow-up, 4.6% of patients developed PSE. Among patients with ischemic stroke, significant risk factors for PSE were younger age (HR = 1.47), living in rural areas (HR = 1.35), admission through the emergency room (HR = 1.33), and longer duration of hospital stay (HR = 1.45). Time-varying analysis revealed elevated HRs for ICH and SAH, particularly in the first 2 years following the stroke. The age-specific HRs also showed an increased risk for those under the age of 65, with a noticeable decrease in risk beyond that age.

CONCLUSION

The risk of developing PSE varies according to stroke subtype, age, and other demographic factors. These findings underscore the importance of tailored poststroke monitoring and management strategies to mitigate the risk of PSE.

The role of NPY signaling pathway in diagnosis, prognosis and treatment of stroke

Neuropeptide Y (NPY), an extensively distributed neurotransmitter within the central nervous system (CNS), was initially detected and isolated from the brain of a pig in 1982. By binding to its G protein-coupled receptors, NPY regulates immune responses and contributes to the pathogenesis of numerous inflammatory diseases. The hippocampus contained the maximum concentration in the CNS, with the cerebral cortex, hypothalamus, thalamus, brainstem, and cerebellum following suit. This arrangement suggests that the substance has a specific function within the CNS. More and more studies have shown that NPY is involved in the physiological and pathological mechanism of stroke, and its serum concentration can be one of the specific biomarkers of stroke and related complications because of its high activity, broad and complex effects. By summarizing relevant literature, this article aims to gain a thorough understanding of the potential clinical applications of NPY in the treatment of stroke, identification of stroke and its related complications, and assessment of prognosis.

Epilepsy and epileptiform activity in late-onset Alzheimer disease: clinical and pathophysiological advances, gaps and conundrums

A growing body of evidence has demonstrated a link between Alzheimer disease (AD) and epilepsy. Late-onset epilepsy and epileptiform activity can precede cognitive deterioration in AD by years, and its presence has been shown to predict a faster disease course. In animal models of AD, amyloid and tau pathology are linked to cortical network hyperexcitability that precedes the first signs of memory decline. Thus, detection of epileptiform activity in AD has substantial clinical importance as a potential novel modifiable risk factor for dementia. In this Review, we summarize the epidemiological evidence for the complex bidirectional relationship between AD and epilepsy, examine the effect of epileptiform activity and seizures on cognition in people with AD, and discuss the precision medicine treatment strategies based on the latest research in human and animal models. Finally, we outline some of the unresolved questions of the field that should be addressed by rigorous research, including whether particular clinicopathological subtypes of AD have a stronger association with epilepsy, and the sequence of events between epileptiform activity and amyloid and tau pathology.

Injury-specific factors in the cerebrospinal fluid regulate astrocyte plasticity in the human brain

The glial environment influences neurological disease progression, yet much of our knowledge still relies on preclinical animal studies, especially regarding astrocyte heterogeneity. In murine models of traumatic brain injury, beneficial functions of proliferating reactive astrocytes on disease outcome have been unraveled, but little is known regarding if and when they are present in human brain pathology. Here we examined a broad spectrum of pathologies with and without intracerebral hemorrhage and found a striking correlation between lesions involving blood-brain barrier rupture and astrocyte proliferation that was further corroborated in an assay probing for neural stem cell potential. Most importantly, proteomic analysis unraveled a crucial signaling pathway regulating this astrocyte plasticity with GALECTIN3 as a novel marker for proliferating astrocytes and the GALECTIN3-binding protein LGALS3BP as a functional hub mediating astrocyte proliferation and neurosphere formation. Taken together, this work identifies a therapeutically relevant astrocyte response and their molecular regulators in different pathologies affecting the human cerebral cortex.

MicroRNAs as Potential Biomarkers of Post-Traumatic Epileptogenesis: A Systematic Review

Structural or post-traumatic epilepsy often develops after brain tissue damage caused by traumatic brain injury, stroke, infectious diseases of the brain, etc. Most often, between the initiating event and epilepsy, there is a period without seizures-a latent period. At this time, the process of restructuring of neural networks begins, leading to the formation of epileptiform activity, called epileptogenesis. The prediction of the development of the epileptogenic process is currently an urgent and difficult task. MicroRNAs are inexpensive and minimally invasive biomarkers of biological and pathological processes. The aim of this study is to evaluate the predictive ability of microRNAs to detect the risk of epileptogenesis. In this study, we conducted a systematic search on the MDPI, PubMed, ScienceDirect, and Web of Science platforms. We analyzed publications that studied the aberrant expression of circulating microRNAs in epilepsy, traumatic brain injury, and ischemic stroke in order to search for microRNAs-potential biomarkers for predicting epileptogenesis. Thus, 31 manuscripts examining biomarkers of epilepsy, 19 manuscripts examining biomarkers of traumatic brain injury, and 48 manuscripts examining biomarkers of ischemic stroke based on circulating miRNAs were analyzed. Three miRNAs were studied: miR-21, miR-181a, and miR-155. The findings showed that miR-21 and miR-155 are associated with cell proliferation and apoptosis, and miR-181a is associated with protein modifications. These miRNAs are not strictly specific, but they are involved in processes that may be indirectly associated with epileptogenesis. Also, these microRNAs may be of interest when they are studied in a cohort with each other and with other microRNAs. To further study the microRNA-based biomarkers of epileptogenesis, many factors must be taken into account: the time of sampling, the type of biological fluid, and other nuances. Currently, there is a need for more in-depth and prolonged studies of epileptogenesis.

An update on the role of Hippo signaling pathway in ischemia-associated central nervous system diseases

The most frequent reason of morbidity and mortality in the world, cerebral ischemia sets off a chain of molecular and cellular pathologies that associated with some central nervous system (CNS) disorders mainly including ischemic stroke, Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy and other CNS diseases. In recent times, despite significant advancements in the treatment of the pathological processes underlying various neurological illnesses, effective therapeutic approaches that are specifically targeted to minimizing the damage of such diseases remain absent. Hippo signaling pathway, characterized by enzyme linked reactions between MSTI/2, LAST1/2, and YAP or TAZ proteins, controls cell division, survival, and differentiation, as well as being engaged in a variety of biological activities, such as the development and transformation of the nervous system. Recently, accumulating studies demonstrated that Hippo pathway takes part in the processes of ischemic stroke, AD, PD, etc., including but not limited to oxidative stress, inflammatory response, blood-brain barrier damage, mitochondrial disorders, and neural cells death. Thus, it's crucial to understand the molecular basis of the Hippo signaling pathway for determining potential new therapeutic targets against ischemia-associated CNS diseases. Here, we discuss latest advances in the deciphering of the Hippo signaling pathway and highlight the therapeutic potential of targeting the pathway in treating ischemia-associated CNS diseases.