Poststroke epilepsy: occurrence, predictors and treatment

Strategic infarct location for post-stroke seizure

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The hot spots of PSS were distributed around the central region of cerebral cortex.

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We observed differences between the distribution of hot spots among patients with early-PSS and those with late-PSS.

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The specific regions of the brain are significantly associated with the development of PSS after cerebral infarction.

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The location of infarction could help clinicians assess the risk of PSS in specific post-stroke stages.

Post-stroke seizure (PSS) can have a strong negative impact on functional recovery after stroke. Researchers have identified numerous risk factors of PSS; however, the relationship between infarction location and PSS remains unclear. We recruited patients who presented with an acute cerebral infarction between 2012 and 2017 and suffered from seizures within 1 year after stroke (PSS group). PSS group was subgrouped into early-PSS and late-PSS groups based on the interval between seizure and stroke. We also recruited an equal number of acute cerebral infarction patients without post-stroke seizures during the follow-up period (Non-PSS group). All brain MRIs from the two groups were processed, whereupon normalized infarct maps from the PSS and Non-PSS groups were compared via voxel- and volumetric-based analyses. A total of 132 subjects were enrolled in the study, including PSS (n = 66, consisting of 31 early-PSS and 35 late-PSS) and Non-PSS (n = 66) patients. No significant differences were observed between the two groups in terms of stroke lateralization or severity. Image analysis revealed that the volume of infarction was larger in the PSS group than in the Non-PSS group; however, the difference did not reach the level of significance. Unlike the Non-PSS group, the PSS group presented hot spots over the left central region, left superior parietal lobule, and right frontal operculum. We observed differences between the distribution of hot spots among patients with early-PSS and those with late-PSS. We found that some brain regions were significantly associated with the development of PSS after ischemic stroke, and these regions differed between cases of early and late PSS. It appears that the location of infarction could help clinicians assess the risk of PSS in specific post-stroke stages.

Post-stroke epilepsy and antiepileptic drug use in men and women

Evidence-based recommendations for choice of antiepileptic drug (AED) in post-stroke epilepsy (PSE) are lacking. The aim of this study was to describe the use and persistence of AEDs when initiating treatment in men and women with PSE. An observational study based on individual-level patient data from a regional healthcare register in Stockholm, Sweden, was conducted. Adults (≥18 years) with a stroke diagnosis 2012-2016, a dispensed prescription of any AED within two years after the stroke, and with an epilepsy-related diagnosis were identified. Multinomial logistic regression and logistic regression were used to identify factors associated with choice of AED and discontinuation within 90 days, respectively. Of 9652 men and 9844 women with a stroke diagnosis, 287 men and 273 women had PSE and were dispensed AED. More than 60% of both men and women with PSE were treated with levetiracetam. Carbamazepine was the second most common drug followed by lamotrigine and valproic acid. There were significant differences in AED choice depending on for instance sex, age and renal impairment. Levetiracetam had the highest persistence in both men and women. Choice of AED, oral anticoagulant use and percutaneous endoscopic gastrostomy (PEG) showed an association with the persistence to therapy. We conclude that in both men and women with PSE, levetiracetam was the most used AED for initiation of treatment and also had the highest persistence.

Modeling poststroke epilepsy and preclinical development of drugs for poststroke epilepsy

Stroke is a severe clinical issue for global public health, representing the third leading cause of death and a major cause of disability in developed countries. Progresses in the pharmacological treatment of the acute stroke have given rise to a significant decrease in its mortality rate. However, as a result, there has been an increasing number of stroke survivors living with disability worldwide. Poststroke epilepsy (PSE) is a common clinical complication following stroke. Seizures can arise in close temporal association with stroke damage and/or after a variably longer interval. Overall, PSE have a good prognosis; in fact, its responding rate to antiepileptic drugs (AEDs) is higher than other types of epilepsy. However, regarding pharmacological treatment, some issues are still unresolved. To this aim, a deeper understanding of mechanisms underlying the transformation of infarcted tissue into an epileptic focus or better from a nonepileptic brain to an epileptic brain is also mandatory for PSE. However, studying epileptogenesis in patients with PSE clearly has several limitations and difficulties; therefore, modeling PSE is crucial. Until now, different experimental models have been used to study the etiopathology of cerebrovascular stroke with or without infarction, but few studies focused on poststroke epileptogenesis and PSE. In this review, we show a brief overview on the features emerging from preclinical research into experimental PSE, which could affect the discovery of biomarkers and therapy strategies for poststroke epileptogenesis. This article is part of the Special Issue "Seizures & Stroke".

New insights into a spectrum of developmental malformations related to mTOR dysregulations: challenges and perspectives

In recent years the role of the mammalian target of rapamycin (mTOR) pathway has emerged as crucial for normal cortical development. Therefore, it is not surprising that aberrant activation of mTOR is associated with developmental malformations and epileptogenesis. A broad spectrum of malformations of cortical development, such as focal cortical dysplasia (FCD) and tuberous sclerosis complex (TSC), have been linked to either germline or somatic mutations in mTOR pathway-related genes, commonly summarised under the umbrella term 'mTORopathies'. However, there are still a number of unanswered questions regarding the involvement of mTOR in the pathophysiology of these abnormalities. Therefore, a monogenetic disease, such as TSC, can be more easily applied as a model to study the mechanisms of epileptogenesis and identify potential new targets of therapy. Developmental neuropathology and genetics demonstrate that FCD IIb and hemimegalencephaly are the same diseases. Constitutive activation of mTOR signalling represents a shared pathogenic mechanism in a group of developmental malformations that have histopathological and clinical features in common, such as epilepsy, autism and other comorbidities. We seek to understand the effect of mTOR dysregulation in a developing cortex with the propensity to generate seizures as well as the aftermath of the surrounding environment, including the white matter.

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.

Prospects of modeling poststroke epileptogenesis

This Review describes the current status of poststroke epilepsy (PSE) with an emphasis on poststroke epileptogenesis modeling for testing new therapeutic agents. Stroke is a leading cause of epilepsy in an aging population. Late-onset "epileptic" seizures have been reported in up to 30% cases after stroke. Nevertheless, the overall prevalence of PSE is 2-4%. Rodent models of stroke have contributed to our understanding of the relationship between seizures and the underlying ischemic damage to neurons. To understand whether acutely generated stroke events lead to a chronic phenotype more closely resembling PSE with recurrent seizures, a limited variety of approaches emerged in early 2000s. These limited methods of causing an occlusion in mice and rats show different infarct size and neurological deficits. The most often employed procedure for inducing focal ischemia is the middle cerebral artery occlusion. This mimics the pathophysiology seen in humans in terms of extent of damage to cortex and striatum. Photothrombosis and endothelin-1 models can similarly evoke episodes of ischemic stroke. These models are well suited to studying mechanisms and biomarkers of epileptogenesis or optimizing novel drug discoveries. However, modeling of PSE is tedious, is highly variable, and lacks validity; therefore, it is not widely implemented in epilepsy research. Moreover, the relevance of ischemic models to specific forms of human stroke remains unclear. Stroke modeling in young male rodents lacks clinical relevance to elderly populations and especially to women, likely as a result of sex differences. Nevertheless, because of the neuronal damage and epileptogenic insult that these models trigger, they are helpful tools in studying acquired epilepsy and prophylactic drug therapy. © 2016 Wiley Periodicals, Inc.

Selective Serotonin Reuptake Inhibitors and Poststroke Epilepsy: A Population-Based Nationwide Study

OBJECTIVE

To investigate the effects of selective serotonin reuptake inhibitors (SSRIs) on poststroke epilepsy in a population-based nationwide study.

PATIENTS AND METHODS

The SSRI group included patients who received a stroke diagnosis from January 1, 2000, through December 31, 2009, and were prescribed SSRIs after stroke. The non-SSRI group enrolled patients with stroke who were not prescribed SSRIs from the Taiwan National Health Insurance Research Database and used propensity score matching based on the index year, duration time, sex, age, type of stroke, and duration of hospitalization. Cox proportional hazards models were used to estimate the risk of epilepsy between the SSRI and comparison groups.

RESULTS

A total of 4688 patients with stroke (2344 in each of the SSRI and non-SSRI cohorts) were enrolled. The cumulative incidence of epilepsy in the SSRI group was significantly higher than that in the comparison group (log-rank P<.001). In the SSRI group, the risk of poststroke epilepsy increased 2.45-fold (95% CI, 1.69- to 3.57-fold) compared with that in the comparison group. Furthermore, the risk of poststroke epilepsy increased with the defined daily dose of SSRIs. For patients with ischemic stroke, SSRIs users had a 2.74-fold higher risk of epilepsy than non users (95% CI, 1.79- to 4.22-fold).

CONCLUSION

In this study, SSRI users had a higher risk of poststroke epilepsy than nonusers. Further study is warranted to investigate the causal relationship between SSRI exposure and poststroke epilepsy.

In-hospital costs in patients with seizures and epilepsy after stroke

OBJECTIVES

To verify the net effect of seizures after stroke on the use of in-hospital health care resources.

METHODS

Consecutive patients with first-ever stroke were admitted to the stroke unit of a Moscow hospital and followed prospectively until death or discharge. Each patient experiencing seizures was matched for age, sex, stroke type, National Institutes of Health Stroke Scale score at admission, and stroke risk factors to 2+ patients with no seizures, as controls. Resources consumed included length of hospital stay, admission to the intensive care unit (ICU), diagnostic tests, medical consultations and treatments. Cost estimates were based on the Russian National Health Service perspective.

RESULTS

The sample comprised 30 patients with in-hospital seizures and 70 matched controls. Patients dying in hospital were 15 of 30 (50%) versus 4 of 70 (5.7%) (p < 0.001). The overall cost of hospital stay was only slightly (nonsignificantly) higher in patients with seizures, but the cost was significantly higher in patients who died than in patients who were discharged alive. Compared to the controls, patients with seizures spent more intensive care unit (ICU) days and required more computed tomography (CT) scans, x-rays, endoscopies, and specialist consultations, causing higher in-hospital costs.

SIGNIFICANCE

In patients with first-ever stroke, seizures per se do not increase the overall in-hospital costs. However, the higher than expected mortality in patients with seizures is associated with additional hospital costs.

The pooled incidence of post-stroke seizure in 102 008 patients

BACKGROUND

Post-stroke seizures and epilepsy may worsen the recovery and increase the disability of stroke patients during their daily lives. However, few meta-analysis studies have been conducted on post-stroke seizures incidence. We carried on a meta-analysis on the incidence rate of post-stroke seizures and associated factors.

METHODS

We searched the Medline, Embase, Web of Science, Science Citation Index, and Cochrane Library electronic databases (1990-2013) to identify observational studies of post-stroke seizures. Two authors independently extracted the related information from all included studies. We calculated the pooled incidence by meta-analysis using the software R version 12.3.

RESULTS

A total of 34 longitudinal cohort studies involving 102 008 patients were included in our meta-analysis. The pooled incidence rate of post-stroke seizures was found to be 0.07 [95% confidence interval (CI), 0.05-0.09] while the rate of post-stroke epilepsy (PSE) was 0.05 (95% CI, 0.04-0.06). The incidence of post-stroke seizures in hemorrhagic stroke (0.10, 0.08-0.13) was much higher than in ischemic stroke (0.06, 0.04-0.08) and when the cortical region was involved (0.15, 0.10-0.21).

CONCLUSIONS

Our meta-analysis showed that seizures occurred in about 6.93% of people with stroke. Seizures occurred more commonly after hemorrhagic stroke and when stroke occurred in the cortical region.

[Epilepsy in the elderly]

BACKGROUND

Diagnostic work-up and treatment of patients who have developed epilepsy after the age of 65 can both be difficult. Epilepsy is one of the most common neurological conditions in the elderly, and the incidence of de novo geriatric epilepsy is rising. The aim of this review is to provide guidance on the management of epilepsy in this patient group.

METHOD

The review is based on a discretionary selection of original articles and reviews found in PubMed using the search term combination 'epilepsy' and 'elderly', and the authors' personal experience.

RESULTS

The seizures, which are most commonly of the focal type, are not infrequently overlooked or misdiagnosed. Cerebrovascular disease is the underlying cause of about half of the cases. When selecting an anticonvulsant, it is important to take age-related physiological changes and comorbidities into consideration. Because elderly patients have a narrower therapeutic window than younger persons and greater susceptibility to cognitive and other side effects, a low starting dose and slower dose titration are particularly important.

INTERPRETATION

The results of studies of young epilepsy patients cannot be extrapolated to apply to elderly patients. More studies directly targeting this patient population are therefore needed. As a general rule, we do not recommend starting on enzyme-inducing drugs such as phenytoin, phenobarbital and carbamazepine, partly because of their high interaction potential.

Seizures in patients with multiple sclerosis: epidemiology, pathophysiology and management

Seizures have been recognized to occur in multiple sclerosis (MS) since early descriptions of the disease. Various studies have attempted to determine the incidence and prevalence of seizures in MS; although they differ in the reported prevalence, seizures do appear to be more common in MS cohorts than in the general population. The pathological underpinning of seizures in MS remains indeterminate. Cortical and subcortical demyelination and inflammation may explain the increased frequency of seizures in MS, although this hypothetical correlation remains to be proven. Management of seizures in MS is similar to the management of seizures in other patients. Consideration of the underlying neurological deficits related to MS may be necessary, and dosages of antiepileptic drugs should be adjusted if increased sensitivity to the adverse effects of these agents or interaction with other centrally acting medications is suspected. The prognosis of epilepsy in patients with MS remains uncertain, with some studies suggesting a more favourable prognosis than others.