Antiepileptogenesis after stroke-trials and tribulations: Methodological challenges and recruitment results of a Phase II study with eslicarbazepine acetate

Association of the Timing and Type of Acute Symptomatic Seizures With Poststroke Epilepsy and Mortality

BACKGROUND

Acute symptomatic seizures (ASyS) increase the risk of epilepsy and mortality after a stroke. The impact of the timing and type of ASyS remains unclear.

METHODS

This multicenter cohort study included data from 9 centers between 2002 and 2018, with a final analysis in February 2024. The study included 4552 adults (2005 female; median age, 73 years) with ischemic stroke and no seizure history. Seizures were classified using International League Against Epilepsy definitions. We examined ASyS occurring within seven days after stroke. The main outcomes were all-cause mortality and epilepsy. Validation of the updated SeLECT score (SeLECT-ASyS) was performed in 3 independent cohorts (Switzerland, Argentina, and Japan) collected between 2012 and 2024, including 74 adults with ASyS.

RESULTS

The 10-year risk of poststroke epilepsy ranged from 41% to 94%, and mortality from 36% to 100%, depending on ASyS type and timing. ASyS on stroke onset day had a higher epilepsy risk (adjusted hazard ratio [aHR], 2.3 [95% CI, 1.3-4.0]; P=0.003) compared with later ASyS. Status epilepticus had the highest epilepsy risk (aHR, 9.6 [95% CI, 3.5-26.7]; P<0.001), followed by focal to bilateral tonic-clonic seizures (aHR, 3.4 [95% CI, 1.9-6.3]; P<0.001). Mortality was higher in those with ASyS presenting as focal to bilateral tonic-clonic seizures on day 0 (aHR, 2.8 [95% CI, 1.4-5.6]; P=0.004) and status epilepticus (aHR, 14.2 [95% CI, 3.5-58.8]; P<0.001). The updated SeLECT-ASyS model, available as an application, outperformed a previous model in the derivation cohort (concordance statistics, 0.68 versus 0.58; P=0.02) and in the validation cohort (0.70 versus 0.50; P=0.18).

CONCLUSIONS

ASyS timing and type significantly affect epilepsy and mortality risk after stroke, improving epilepsy prediction and guiding patient counseling.

Are antiseizure medications disease modifiers?

The International League Against Epilepsy (ILAE) is proposing a new nomenclature, replacing the confusing term antiepileptic drugs (AEDs) with antiseizure medications (ASMs). This approach has been partly motivated by the emergence of new treatments with antiepileptogenic or, more precisely, disease-modifying effects. This implies an effect on the temporal course of the disease, even when treatment is discontinued. However, the terms ASM and disease-modifying are not mutually exclusive. In some cases, ASMs can have this property. however, demonstrating this disease-modifying effect, and hence the development of these molecules, remains complex and difficult. The disease-modifying effect of ASM seems to depend on its etiological or pathophysiological effect on the developing epileptic disease, but also on other characteristics: target on etiological or pathophysiological mechanisms of the disease, level of cerebral maturation, time after onset of an epileptogenic event, dosage and duration of treatment. The development of this new type of treatment requires a better definition of the target populations, a better understanding of the cascade of epileptogenic phenomena, and the definition of new diagnostic and prognostic markers for epilepsy.

Clinical trials of prevention of acquired epilepsy: New proof-of-concept approach to restart trials

Approximately 20% of epilepsy is caused by acute central nervous system insults such as traumatic brain injury (TBI), stroke, and infection. There is a latent period of weeks to years between the insult and epilepsy onset, which offers an opportunity to prevent epilepsy. No preventive treatments exist. Their development is a major unmet need in neurology. For logistical reasons, epilepsy acquired after TBI, posttraumatic epilepsy (PTE), is most suitable for epilepsy prevention studies. In the past 20 years, preclinical PTE research has flourished, offering potential treatments to prevent PTE, but clinical development has been dormant. The major barrier in the development of PTE preventive treatment is the lack of a viable proof of concept (POC) trial design. PTE trials use the first late unprovoked posttraumatic seizure as an outcome measure, which necessitates a long (~2-year) follow-up and makes POC studies nonfeasible. A reliable biomarker of early PTE detection would allow shorter follow-up duration and facilitate POC studies, but such a biomarker is not yet available. Biomarker, POC, and randomized clinical trial studies have virtually identical designs in terms of patient inclusion and follow-up. Done sequentially, the studies would take a generation to complete. We propose a novel trial design for studies of PTE prevention that combines discovery of biomarker(s) of early PTE detection with POC study and uses an adaptive study POC-phase 3 continuation design approach to incorporate POC study into phase 3 study following an interim futility analysis after 6 months of treatment of the first 25% of the cohort, the POC population. This approach would establish a POC model for treatment of PTE prevention, shorten development of PTE prevention treatment, and reopen the door to clinical trials to prevent epilepsy.

Prognostic models for seizures and epilepsy after stroke, tumors and traumatic brain injury

Epilepsy is a frequent consequence of acute brain injuries, such as stroke, brain tumors, and traumatic brain injury (TBI). Accurate prediction of epilepsy is essential for early intervention and improved patient outcomes. This review evaluates the best-established prognostic models, including the SeLECT and CAVE scores, which estimate the risk of developing seizures and epilepsy following these injuries. The review highlights their clinical applicability, predictive accuracy, and limitations for different etiologies. In addition to providing practical tables for risk estimation, we also offer user-friendly online calculators for these models at www.predictepilepsy.com to facilitate clinical implementation. These tools help identify high-risk patients and support decision-making for follow-up and treatment. Furthermore, we discuss the potential of integrating electrophysiological data, including EEG biomarkers, to further enhance prediction accuracy and patient care. These insights highlight the need for further refinement and validation of predictive models, enabling more personalized treatment strategies and better patient care.

Acute symptomatic seizures in patients with recurrent ischemic stroke: A multicentric study

OBJECTIVE

Epileptic seizures occur frequently after stroke due to changes in brain function and structure, and up to around 10% of stroke patients experience stroke recurrence in the first year. We aimed to establish the risk of acute symptomatic seizures in patients with recurrent stroke.

METHODS

Retrospective cohort study including consecutive admissions to a Stroke Unit due to acute ischemic stroke, during a 5-year period. Additional inclusion of patients admitted to two centers in different countries to corroborate findings (confirmatory cohort). We aimed to compare acute symptomatic seizure incidence in patients with and without previous stroke. Patients with history of epilepsy were excluded. Logistic regression modeling was performed to identify predictors in middle cerebral artery (MCA) stroke.

RESULTS

We included 1473 patients (1085 with MCA stroke), of which 117 had a recurrent ischemic stroke (84 with MCA stroke). Patients with recurrent stroke had a seizure risk during hospital stay similar to that of patients with a first-ever stroke (5.1% vs. 4.5%, OR 1.15, 95% CI .48-2.71, p = .75). Risk of acute symptomatic seizures was also similar (5.0% vs. 4.1, OR 1.22, 95% CI .29-5.27, p = .78). Older age, female sex, and hemorrhagic transformation were predictors of seizures in patients with a first MCA ischemic stroke, but not in recurrent stroke patients. Electrographic characteristics were similar between the two groups in patients who had an electroencephalogram (46 with first stroke, 5 with recurrent stroke). The low rate of seizures (1.5%) in the confirmatory cohort (n = 198) precluded full comparison with the initial cohort. Nevertheless, the rate of seizures was not higher in stroke recurrence.

SIGNIFICANCE

History of previous stroke was not associated with an increased risk of acute symptomatic seizures during hospital stay. Larger, prospective studies, with prospective electrophysiological evaluation, are needed to explore the impact of stroke recurrence on seizure risk.

Drug arrows in the quiver-antiseizure, antiepileptic and neuroprotective medication: Treatment and future aspects. A focused review

Drug discovery for the treatment of epilepsy is entering a new era especially with the advancement of genetic therapies as disease modifying, antiepileptogenic therapies. Even new ideas about re-purposed medication with purposed epileptogenic properties have been suggested. The possibilities are enormous, and it is encouraging that so many ideas are flourishing. The focus of this review is to discuss where to concentrate efforts to improve the lives of people with epilepsy (PWE) with medical treatment, especially the elderly who have many challenges besides just seizures. Thus, the arrow needs to be not only focused on DRE patients, but to try to redirect the arrow to prevent the development of seizures before onset as well as preventing refractoriness at the very beginning herald by the first seizures.

Role of blood-brain barrier dysfunction in the development of poststroke epilepsy

Stroke is a major contributor to mortality and morbidity worldwide and the most common cause of epilepsy in the elderly in high income nations. In recent years, it has become increasingly evident that both ischemic and hemorrhagic strokes induce dysfunction of the blood-brain barrier (BBB), and that this impairment can contribute to epileptogenesis. Nevertheless, studies directly comparing BBB dysfunction and poststroke epilepsy (PSE) are largely absent. Therefore, this review summarizes the role of BBB dysfunction in the development of PSE in animal models and clinical studies. There are multiple mechanisms whereby stroke induces BBB dysfunction, including increased transcytosis, tight junction dysfunction, spreading depolarizations, astrocyte and pericyte loss, reactive astrocytosis, angiogenesis, matrix metalloproteinase activation, neuroinflammation, adenosine triphosphate depletion, oxidative stress, and finally cell death. The degree to which these effects occur is dependent on the severity of the ischemia, whereby cell death is a more prominent mechanism of BBB disruption in regions of critical ischemia. BBB dysfunction can contribute to epileptogenesis by increasing the risk of hemorrhagic transformation, increasing stroke size and the amount of cerebral vasogenic edema, extravasation of excitatory compounds, and increasing neuroinflammation. Furthermore, albumin extravasation after BBB dysfunction contributes to epileptogenesis primarily via increased transforming growth factor β signaling. Finally, seizures themselves induce BBB dysfunction, thereby contributing to epileptogenesis in a cyclical manner. In repairing this BBB dysfunction, pericyte migration via platelet-derived growth factor β signaling is indispensable and required for reconstruction of the BBB, whereby astrocytes also play a role. Although animal stroke models have their limitations, they provide valuable insights into the development of potential therapeutics designed to restore the BBB after stroke, with the ultimate goal of improving outcomes and minimizing the occurrence of PSE. In pursuit of this goal, rapamycin, statins, losartan, semaglutide, and metformin show promise, whereby modulation of pericyte migration could also be beneficial.

New epilepsy therapies in development

Epilepsy is a common brain disorder, characterized by spontaneous recurrent seizures, with associated neuropsychiatric and cognitive comorbidities and increased mortality. Although people at risk can often be identified, interventions to prevent the development of the disorder are not available. Moreover, in at least 30% of patients, epilepsy cannot be controlled by current antiseizure medications (ASMs). As a result of considerable progress in epilepsy genetics and the development of novel disease models, drug screening technologies and innovative therapeutic modalities over the past 10 years, more than 200 novel epilepsy therapies are currently in the preclinical or clinical pipeline, including many treatments that act by new mechanisms. Assisted by diagnostic and predictive biomarkers, the treatment of epilepsy is undergoing paradigm shifts from symptom-only ASMs to disease prevention, and from broad trial-and-error treatments for seizures in general to mechanism-based treatments for specific epilepsy syndromes. In this Review, we assess recent progress in ASM development and outline future directions for the development of new therapies for the treatment and prevention of epilepsy.

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.

A profile of azetukalner for the treatment of epilepsy: from pharmacology to potential for therapy

INTRODUCTION

Epilepsies are a group of heterogeneous brain disorder, and antiseizure medications (ASMs) are the mainstay of treatment. Despite the availability of more than 30 drugs, at least one third of individuals with epilepsy are drug-resistant. This emphasizes the need for novel compounds that combine efficacy with improved tolerability.

AREAS COVERED

A literature review on the pharmacology, efficacy, tolerability, and safety of azetukalner (XEN1101), a second-generation opener of neuronal potassium channels currently in Phase 3 development as ASM.

EXPERT OPINION

Results from the phase 2b clinical trial strongly support the ongoing clinical development of azetukalner as a new ASM. Its pharmacokinetic properties support convenient once-daily dosing, eliminating the need for titration at initiation or tapering at the conclusion of treatment. CYP3A4 is the main enzyme involved in its metabolism and drug-drug interactions can affect the drug exposure. Preliminary analysis of an ongoing open-label study reveals no reported pigmentary abnormalities. The upcoming Phase 3 clinical trials are expected to provide further insight into the efficacy, tolerability, and safety of azetukalner in treating focal-onset and primary generalized tonic-clonic seizures. Structurally distinct from currently marketed ASMs, azetukalner has the potential to be the only-in-class Kv7.2/7.3 opener on the market upon regulatory approval.

Britton J, Laux L, Trinka E, Rubinos C, McDonald TJW, Lado FA, Bebin M, Papadelis C, Struck AF, Maciel CB, Velasco AL, Chandran A, Pati S, Tandon N, Vaca GFB, Berl MM, Moosa AN. It's About Time! Timing in Epilepsy Evaluation and Treatment

The 2023 American Epilepsy Society Annual Course "It's About Time" addressed timing in epilepsy evaluation and treatment with respect to health disparity and vulnerable populations and diagnostic, clinical, and epilepsy surgery evaluation. This comprehensive course included topics on gaps in epilepsy care and optimization of behavioral health for patients with epilepsy. The summary details current knowledge in areas of seizure forecasting and epileptogenesis. Intricacies and controversies over timing were discussed for treatment of nonconvulsive seizures and ictal-interictal patterns, acute symptomatic seizures, neuromodulation versus surgery, and epilepsy surgery in status epilepticus. Timing regarding clinical care in autoimmune-associated epilepsy, developmental and epileptic encephalopathy, and dietary therapy were examined. Additionally, salient topics on using novel biomarkers and collaboration with neuropsychological outcomes were also tackled in this all-encompassing lecture series.