Clinical predictors of late-onset seizures and epilepsy in patients with cerebrovascular 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.

Risk factors for early seizure after revascularization in patients with moyamoya disease

BACKGROUND

To investigate the risk factors for early seizure after revascularization in patients with moyamoya disease (MMD).

METHODS

A total of 298 patients with MMD diagnosed in our hospital from 2015 to 2018 were analyzed retrospectively. We summarized the characteristics of seizure after revascularization in patients with MMD and analyzed the predictors of early postoperative seizure.

RESULTS

We identified 15 patients with MMD who developed seizures within 1 week after revascularization. According to logistic regression analysis, age (OR: 1.04, 95% CI 0.998-1.086; P = 0.060) and infarct side (OR: 1.92, 95% CI 0.856-4.290; P = 0.113) were not significantly associated with incident early seizure. Postoperative infarction (OR: 12.89, 95% CI 4.198-39.525; P = 0.000) and preoperative cerebral infarction (OR: 4.08, 95% CI 1.267-13.119; P = 0.018) were confirmed as risk factors for early seizure.

CONCLUSIONS

We believe that a history of preoperative infarction and new infarction are independent risk factors of early seizure in patients with MMD after revascularization.

[Risk factors for post stroke epilepsy]

Stroke is the leading cause of death and disability in the world. The prevalence of post-stroke epilepsy increases with the increase in the number of stroke cases. Epilepsy may develop in 10% of post-stroke cases and first-diagnosed seizures may develop in 55%. Most often they occur in people who have had intracerebral or subarachnoid haemorrhage. A huge number of factors influence the development of post-stroke seizures and epilepsy. The role of some of them is not in doubt. However, in most cases, the influence of a factor remains controversial and participation in the development of post-stroke epilepsy is not fully proven. The management of post-stroke epilepsy is of great clinical importance, since patients with seizures after a stroke have a higher mortality and disability than those without seizures. Attacks worsen the quality of life of patients, can slow the recovery of functions damaged as a result of a stroke, and aggravate cognitive impairment. Social consequences of post-stroke epilepsy play an important role as well.

Refractory Left Focal Motor Status Epilepticus as Initial Clinical Presentation of Acute Basilar Artery Thrombosis

Seizures are uncommon with posterior circulation strokes. They are more often associated with anterior circulation strokes, with only a limited number of cases of status epilepticus reported to be related to brain stem ischemia. The literature includes case reports of generalized tonic-clonic seizures and associated status epilepticus as an initial presentation of acute basilar artery thrombosis. However, there are only rare cases reporting focal motor seizure as status epilepticus in the setting of acute basilar artery thrombosis, an important clinical presentation that should prompt evaluation for acute brain stem ischemia.

Multifactorial Predictors of Late Epileptic Seizures Related to Stroke: Evaluation of the Current Possibilities of Stratification Based on Existing Prognostic Models-A Comprehensive Review

Background: Epilepsy associated with strokes is a significant clinical and public health problem and has a negative impact on prognosis and clinical outcome. A late epileptic seizure occurring seven days after stroke is actually equated with poststroke epilepsy due to the high risk of recurrence. Predictive models evaluated in the acute phase of stroke would allow for the stratification and early selection of patients at higher risk of developing late seizures. Methods: The most relevant papers in this field were reviewed to establish multifactorial predictors of late seizures and attempt to standardize and unify them into a common prognostic model. Results: Clinical and radiological factors have become the most valuable and reproducible predictors in many reports, while data on electroencephalographic, genetic, and blood biomarkers were limited. The existing prognostic models, CAVE and SeLECT, based on relevant, readily available, and routinely assessed predictors, should be validated and improved in multicenter studies for widespread use in stroke units. Conclusions: Due to contradictory reports, a common and reliable model covering all factors is currently not available. Further research might refine forecasting models by incorporating advanced radiological neuroimaging or quantitative electroencephalographic analysis.

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

OBJECTIVES

Stroke is a common cause of adult-onset epilepsy (post-stroke epilepsy, PSE). Despite an increasing awareness, there is a concern for underdiagnosis of the condition. We aimed to study the adherence to the latest updated epilepsy definition, as well as the incidence and diagnosis of PSE in an ischemic stroke cohort admitted to a tertiary University Hospital.

MATERIALS AND METHODS

We retrospectively investigated the occurrence and diagnosis of unprovoked seizures and PSE in all ischemic stroke patients admitted to Karolinska University Hospital in Stockholm during 2015 and registered in the Swedish Stroke Register. Patient records were scrutinized for the presence of post-stroke seizures/epilepsy.

RESULTS

A total of 240 patients fulfilling the inclusion criteria were surveyed. Median follow-up time was 1062 days (IQR 589-1195 days). Thirteen patients were diagnosed with PSE according to the study criteria, the incidence of PSE 23/1000 person-years (95% CI 13-38/1000 person-years). Median time to PSE from stroke-onset was 237 days (IQR 33-688). Eleven of 13 PSE patients received an epilepsy diagnosis, eight patients after one unprovoked seizure, and three patients after two.

CONCLUSIONS

The majority of PSE patients were given a correct epilepsy diagnosis and treated with antiepileptic drugs. However, this study suggests that there still is potential for improvement in the adherence to the latest updated epilepsy definition. The incidence of PSE in a Swedish ischemic stroke cohort using updated epilepsy definitions is similar to previous studies. Larger studies are needed to confirm our findings on the incidence of PSE.

Post-stroke epilepsy

Post-stroke epilepsy (PSE) is a common complication after stroke, yet treatment options remain limited. While many physicians prescribe antiepileptic drugs (AED) for secondary prevention of PSE, it is unclear which treatments are most effective in the prevention of recurrence of symptoms, or whether such therapy is needed for primary prevention. This review discusses the current understanding of epidemiology, diagnoses, mechanisms, risk factors, and treatments of PSE.

Computed tomography perfusion as a diagnostic tool for seizures after ischemic stroke

INTRODUCTION

Cerebral cortical ischemia is a risk factor for post-stroke seizures. However, the optimal imaging method is unclear. We investigated CT perfusion (CTP) in detecting cortical ischemia and its correlation with post-stroke seizures compared with non-contrast CT (NCCT).

METHODS

We included patients with acute ischemic stroke admitted to the Royal Melbourne Hospital between 2009 and 2014. Post-stroke seizure information was collected. Cortical involvement was determined on acute NCCT and CTP (T max, cerebral blood volume [CBV], and cerebral blood flow [CBF]). The association between cortical involvement detected by different imaging modalities and post-stroke seizures was examined.

RESULTS

Three-hundred fifty-two patients were included for analysis. Fifty-nine percent were male, and median age was 73 years (inter-quartile range 61-82). Follow-up was available for 96 %; median follow-up duration was 377 days (inter-quartile range 91-1018 days). Thirteen patients had post-stroke seizures (3.9 %). Cortical involvement was significantly associated with post-stroke seizures across all modalities. CBV had the highest hazard ratio (11.3, 95 % confidence interval (CI) 1.1-41.2), followed by NCCT (5.3, 95 % CI 1.5-18.0) and CBF (4.2, 95 % CI 1.1-15.2). Sensitivity was highest for T max (100 %), followed by CBV and CBF (both 76.9 %) and NCCT (63.6 %). Specificity was highest for CBV (77.8 %), then NCCT (75.6 %), CBF (54.0 %), and T max (29.1 %). Receiver-operating characteristic area under the curve was significantly different between imaging modalities (p < 0.001), CBV 0.77, NCCT 0.70, CBF 0.65, and T max 0.65.

CONCLUSION

CTP may improve sensitivity and specificity of cortical involvement for post-stroke seizures compared to NCCT.

A Large-Scale Study Indicates Increase in the Risk of Epilepsy in Patients With Different Risk Factors, Including Rheumatoid Arthritis

Peripheral neuropathy and inflammatory reactions of the central nervous system may accompany rheumatoid arthritis (RA). Inflammatory processes play a critical role in epilepsy. Therefore, we conducted this study to determine the risk of epilepsy in patients with RA.The RA cohort comprised patients ages 20 years and older who were newly diagnosed with RA between 2000 and 2011, with data obtained from the Registry of Catastrophic Illnesses Patient Database. Patients without RA were frequency matched with an RA cohort at a 1:1 ratio according to age, sex, and year of RA diagnosis.The overall crude hazard ratio (HR) for epilepsy was 1.27-fold higher in the RA cohort compared with that in the controls. After adjustment for age, sex, comorbidities, and medications, the patients with RA were associated with an increased risk of epilepsy compared with those without RA (adjusted HR [aHR] = 1.52, 95% confidence interval [CI] = 1.12-2.07). Compared with the RA patients with ≤ 560 days of nonsteroidal anti-inflammatory drug (NSAID) use, the RA patients with 1181 to 2145 and >2145 days of NSAID use had a significantly lower risk of epilepsy (aHR = 0.35, 95% CI = 0.24-0.52 and aHR = 0.15, 95% CI = 0.09-0.24, respectively).This study provides compelling evidence of an increased risk of epilepsy in patients with RA. The period of NSAID treatment is negatively associated with the risk of epilepsy in RA patients.

Cocaine use as an independent predictor of seizures after aneurysmal subarachnoid hemorrhage

OBJECTIVE

Seizures are relatively common after aneurysmal subarachnoid hemorrhage (aSAH). Seizure prophylaxis is controversial and is often based on risk stratification; middle cerebral artery (MCA) aneurysms, associated intracerebral hemorrhage (ICH), poor neurological grade, increased clot thickness, and cerebral infarction are considered highest risk for seizures. The purpose of this study was to evaluate the impact of recent cocaine use on seizure incidence following aSAH.

METHODS

Prospectively collected data from aSAH patients admitted to 2 institutional neuroscience critical care units between 1991 and 2009 were reviewed. The authors analyzed factors that potentially affected the incidence of seizures, including patient demographic characteristics, poor clinical grade (Hunt and Hess Grade IV or V), medical comorbidities, associated ICH, intraventricular hemorrhage (IVH), hydrocephalus, aneurysm location, surgical clipping and cocaine use. They further studied the impact of these factors on "early" and "late" seizures (defined, respectively, as occurring before and after clipping/coiling).

RESULTS

Of 1134 aSAH patients studied, 182 (16%) had seizures; 81 patients (7.1%) had early and 127 (11.2%) late seizures, with 26 having both. The seizure rate was significantly higher in cocaine users (37 [26%] of 142 patients) than in non-cocaine users (151 [15.2%] of 992 patients, p = 0.001). Eighteen cocaine-positive patients (12.7%) had early seizures compared with 6.6% of cocaine-negative patients (p = 0.003); 27 cocaine users (19%) had late seizures compared with 10.5% non-cocaine users (p = 0.001). Factors that showed a significant association with increased risk for seizure (early or late) on univariate analysis included younger age (< 40 years) (p = 0.009), poor clinical grade (p = 0.029), associated ICH (p = 0.007), and MCA aneurysm location (p < 0.001); surgical clipping was associated with late seizures (p = 0.004). Following multivariate analysis, age < 40 years (OR 2.04, 95% CI 1.355-3.058, p = 0.001), poor clinical grade (OR 1.62, 95% CI 1.124-2.336, p = 0.01), ICH (OR 1.95, 95% CI 1.164-3.273, p = 0.011), MCA aneurysm location (OR 3.3, 95% CI 2.237-4.854, p < 0.001), and cocaine use (OR 2.06, 95% CI 1.330-3.175, p = 0.001) independently predicted seizures.

CONCLUSIONS

Cocaine use confers a higher seizure risk following aSAH and should be considered during risk stratification for seizure prophylaxis and close neuromonitoring.

Analysis of risk factors for first seizure after stroke in Chinese patients

The aim of this study is to assess related risk factors and predict early- and late-onset seizure after first-ever stroke. A total of 2474 consecutive patients with initial stroke in China from 1997 to 2007 were retrospectively investigated, in which, 24 clinical and radiological indexes were used for evaluation. Odds ratio (OR) and 95% confidence interval (CI) were calculated by logistic regression. A total of 232 (11.1%) of patients developed seizures during a mean follow-up period of 18 months, with 123 experiencing early-onset and 109 late-onset seizure. The independent risk factors for early-onset seizure were large lesion (OR = 9.36), subarachnoid hemorrhage (OR = 5.28), initial hyponatremia (OR = 2.10), and cortical involvement (OR = 1.33). The independent risk factors for late-onset seizure were cortical involvement (OR = 11.84) and large lesion (OR = 1.87). These results demonstrated that the risk factors for early seizure after stroke are large lesion, subarachnoid hemorrhage, and cortical involvement. Surprisingly, hyponatremia also predicts seizure in stroke patients. Cortical involvement is a major risk factor for late-onset seizure after stroke.

Clinical, laboratory, and radiographic predictors of the occurrence of seizures following aneurysmal subarachnoid hemorrhage

Object

At present, the administration of prophylactic antiepileptic medication following aneurysmal subarachnoid hemorrhage (SAH) is controversial, and the practice is heterogeneous. Here, the authors sought to inform clinical decision making by identifying factors associated with the occurrence of seizures following aneurysm rupture.

Methods

Exploratory analysis was performed on 413 patients enrolled in CONSCIOUS-1 (Clazosentan to Overcome Neurological Ischemia and Infarction Occurring after Subarachnoid Hemorrhage), a prospective randomized trial of clazosentan for the prevention of angiographic vasospasm. The association among clinical, laboratory, and radiographic covariates and the occurrence of seizures following SAH were determined. Covariates with a significance level of p < 0.20 on univariate analysis were entered into a multivariate logistic regression model. Receiver operating characteristic (ROC) curve analysis was used to define optimal predictive thresholds.

Results

Of the 413 patients enrolled in the study, 57 (13.8%) had at least 1 seizure following SAH. On univariate analysis, a World Federation of Neurosurgical Societies grade of IV–V, a greater subarachnoid clot burden, and the presence of midline shift and subdural hematomas were associated with seizure activity. On multivariate analysis, only a subarachnoid clot burden (OR 2.76, 95% CI 1.39–5.49) and subdural hematoma (OR 5.67, 95% CI 1.56–20.57) were associated with seizures following SAH. Using ROC curve analysis, the optimal predictive cutoff for subarachnoid clot burden was determined to be 21 (of a possible 30) on the Hijdra scale (area under the curve 0.63).

Conclusions

A greater subarachnoid clot burden and subdural hematoma are associated with the occurrence of seizures after aneurysm rupture. These findings may help to identify patients at greatest risk for seizures and guide informed decisions regarding the prescription of prophylactic anticonvulsive therapy. Clinical trial registration no.: NCT00111085 (ClinicalTrials.gov).

Seizures after cerebrovascular events: risk factors and clinical features

BACKGROUND

Epileptic seizures are well known sequelae of patients with stroke but only little is known about the different risk factors and about the influence of the different types of stroke including sinus thrombosis and bleedings on developing such seizures. Further, the association of post-stroke seizures and conventional vascular risk factors has not been evaluated to date.

METHODS

We performed a cohort study on a sample of 593 consecutive patients with different types of cerebrovascular events. In 421 patients, sufficient data were obtained in a personal interview over a mean observation period of 30 months. Data regarding the clinical history were recorded from the patients' charts.

RESULTS

The total prevalence of epileptic seizures was 11.6%, the total annual risk was 4.6%. We detected the following significant risk factors: younger age at stroke; higher NIH stroke scale score; any coagulopathy. TIA was found significantly less frequent as a cause of seizures as compared to infarction, bleeding, and sinus thrombosis. Patients with bleeding (14.3%) and with sinus thrombosis (16.3%) were significantly more frequent in the seizure group than in the non-seizure group (6.7% and 1.6%, respectively). The location of stroke, including cortical versus subcortical, did not influence the risk of seizures. The majority of patients developed secondary generalized seizures (57.1%). In adjusted analyses, the two major risk factors for post-stroke epilepsy were a higher NIH stroke scale and a sinus thrombosis as the initial cerebrovascular event. Common lifestyle, vascular, and metabolic risk factors of stroke and for dementia were not associated with the development of seizures.

CONCLUSIONS

In conclusion, our data show that epileptic seizures occur in particular after major strokes and in sinus thrombosis. Interestingly, conventional vascular risk factors were not associated with the occurrence of post-stroke seizures. Considering the risk for seizures after certain types of cerebrovascular events might help to early identify patients for anticonvulsive treatment. In the future, it should be investigated whether these patients might benefit from pre-emptive anticonvulsant treatment.

Seizures and epilepsy in patients with a posterior circulation infarct

Seizures occur mainly in patients with cortical infarcts in the anterior circulation. Those related to a posterior circulation infarct (POCI) are considered rare. This study investigated the characteristics of patients with seizures related to a POCI. A total of 180 consecutive patients admitted with a POCI had a 2- to 7-year follow-up; 24 of them (13.6%) developed seizures. Vascular risk factors, etiology and extension of the infarct, degree of neurologic impairment, and outcome were compared in the patients with and without seizures. Complex partial type seizure was the most common presentation. Stroke characteristics were largely the same in the patients with and without seizures. History of a previous stroke was noted in 62.5% of the seizure group and in 17.9% of the nonseizure group (P < .001). Clinical outcome was worse in the seizure group (P = .004). The relative incidence of seizures in patients with a POCI was not lower than that in the overall stroke population. The high incidence of recurrent stroke is the main risk factor for seizures in patients with a POCI. The seizures themselves are responsible for the increased dependence rate.

[Seizures and epilepsies after stroke]

Epilepsies after stroke represent 20% of all adult-onset epilepsies and exhibit special characteristics with respect to diagnosis, treatment, and prognosis. Patients are frequently amnestic for their seizures the signs of which can be very subtle. Postictal pareses and confusional states can last for days, which further complicate diagnosis. Single seizures after stroke were reported in 2% to 10% of cases, and community-based studies found epilepsies in 3% to 4% of stroke patients. Analyses of subgroups identified epilepsy risks of 3% after ischemic infarction, 6% to 10% after intracerebral hemorrhage, and 9% after subarachnoid hemorrhage. Status epilepticus developed in less than 1% of stroke patients. Besides etiology, further risk factors for epilepsy comprise: remote seizures (latency >2 weeks, risk of recurrence >50%) more than early seizures (latency <2 weeks, risk of recurrence <50%), extent of stroke, cortical involvement, and degree of neurological deficit. The first appearance of seizures in patients older than 60 years represents a risk factor for future stroke with a hazard ratio of 2.89.There is currently no sufficient evidence for starting AED treatment before seizures occur. The benefit is still unclear of starting AED after a single early post-stroke seizure. Most authors recommend AED treatment after the second seizure but also after a first remote seizure because of the high risk of seizure recurrence in these situations. Possible pharmacokinetic interactions should be considered when choosing AED. Especially the first-generation AED carry the potential to interact with comedication, which is usually seen in stroke patients receiving substances such warfarin and salicylates. Only very few studies investigate specific AED exclusively in stroke patients. Lamotrigine and gabapentin have been successfully tested in these patients.

Epilepsy and dementia in the elderly

Epilepsy is a frequent condition in the elderly; however, it remains a relatively understudied condition in older adults with dementia. The diagnosis of a seizure is particularly difficult and is most often based on questions to the caregiver. Epilepsy in dementia has significant consequences on the prognosis of the underlying dementia: it can result in a worsening of cognitive performance, particularly in language, as well as a reduction in autonomy, a greater risk of injury and a higher mortality rate. In this review, management strategies are recommended for the clinician. The presence of pre-existing Alzheimer's disease does not exempt the clinician from ruling out other symptomatic causes of seizures. Anti-epileptic drugs (AED) should be started only after the diagnosis has been clearly established, when the risk of recurrence is high, and with monotherapy whenever possible. Although few data are available, the more recent AED offer significant advantages over the older medications in this context.

Characteristics and outcomes of patients with seizures according to the time of onset in relation to stroke

BACKGROUND/AIM

Although most late-onset seizures (LS) appear within 2 years after stroke, some of them occur later and their characteristics are unknown. The aim of this study was to compare the characteristics of patients with very-late-onset seizures (VLS) to those with early-onset seizures (ES) and those with LS.

PATIENTS

The study group consisted of 204 patients with stroke-related seizures (29 ES, 128 LS and 47 VLS).

RESULTS

Intracranial haemorrhage was a more frequent cause of ES than of LS and no cause at all of VLS. On the other hand, 25% of the VLS were related to lacunar strokes. Status epilepticus occurred in 20.7% of the ES, in 11.7% of the LS and in 2.1% of the VLS patients. Seizure recurrences were 13.8% in the ES, 54.7% in the LS and 34.0% in the VLS group. Neurological impairment, at stroke onset, and the degree of disability were more severe in patients with ES compared to those with LS and were very mild in the VLS group. The EEG findings as a whole did not show significant differences between the three groups, although a normal EEG was more frequent in the VLS group.

CONCLUSION

VLS occur in patients with minor ischaemic strokes with good recovery and benign disease course.

Incidence of seizures in the acute phase of stroke: a population-based study

PURPOSE

The incidence of seizures within 24 h of acute stroke has not been studied extensively. We aimed to establish the incidence of acute poststroke seizures in a biracial cohort and to determine whether acute seizure occurrence differs by race/ethnicity, stroke subtype, and/or stroke localization.

METHODS

We identified all stroke cases between July 1993 and June 1994 and in 1999 within the population of the Greater Cincinnati metropolitan region. Patients with a prior history of seizures/epilepsy were excluded from analysis.

RESULTS

A total of 6044 strokes without a history of seizure(s) were identified; 190 (3.1%) had seizures within the first 24 h of stroke onset. Of ICH/SAH patients, 8.4% had a seizure within the first 24 h of stroke onset (p <or= 0.0001 vs. all other stroke subtype). Of the patients with ischemic stroke, we observed higher incidence of seizures in cardioembolic versus small or large vessel ischemic (p = 0.02) strokes. Patients with seizures experienced higher mortality than patients without seizures (p < 0.001) but seizures were not an independent risk factor of mortality at 30 days after stroke. Independent risk factors for seizure development included hemorrhagic stroke, younger age, and prestroke Rankin score of >or=1. Race/ethnicity or localization of the ischemic stroke did not influence the risk for seizure development in the studied population.

DISCUSSION

The overall incidence of acute seizures after stroke was 3.1%, with a higher incidence seen in hemorrhagic stroke, younger patients, and those presenting with higher prestroke Rankin scores. Acute seizures were associated with a higher mortality at 30 days after stroke.

Chronic obstructive pulmonary disease as a risk factor for stroke-related seizures

Chronic obstructive pulmonary disease (COPD) is a risk factor for cardiovascular disorders and different types of stroke. The present retrospective study investigates whether COPD is also a risk factor for the development of seizures in stroke patients. The study population consisted of 237 patients with stroke-related seizures. The control population was composed of 939 patients, admitted for a stroke between 2002 and 2004 and who did not develop epileptic spells on a follow up of 2 years. The stroke type and aetiology, and the vascular risk factors, including COPD, were compared. The seizure patients were older (P = 0.009) and had more arterial hypertension (P = 0.046) and cardiac-embolic strokes (P = 0.045) than the control group. On logistic regression only partial anterior circulation syndrome/infarct (PACS/I) and COPD (P < 0.001) emerged as independent risk factors for the development of seizures in stroke patients. The occurrence of seizures was not related to the severity of the COPD or to its type of treatment. The present study confirms that seizures occur most frequently in patients with a PACS/I. Although we were unable to demonstrate why COPD is a risk factor for seizures in stroke patients, its frequent associated nocturnal oxygen desaturation seems to be the most plausible explanation. Further prospective are needed to assess the role of COPD as a possible independent risk factor for stroke-related seizures.

Epileptic fits and epilepsy in the elderly: general reflections, specific issues and therapeutic implications

Seizures and epilepsy are commonly encountered in the elderly. Diagnosis is not always straightforward as reliable history is often difficult to obtain and EEG findings can be non-specific. When to treat and how may be difficult choices as adequate studies in elderly are rather scarce. Treatment should be based on careful assessment and comparison of risk/benefit profiles of various anti-epileptic drugs (AEDs) in this specific elderly population. Since most AEDs are effective in terms of seizure control in the elderly, the choice of treatment is often determined by tolerability, pharmacokinetic profile and drug interactions of AEDs. As recently introduced AEDs have a better safety profile compared to older agents it seems logical to initiate treatment in the frail elderly patient with those more modern AEDs. In this review some distinctive clinical features of epilepsy in the elderly are discussed in three sections (general issues, special issues and selected treatment options with special reference to medicinal treatment).

Seizures and epilepsy in patients with lacunar strokes

BACKGROUND

The relation between seizures and small subcortical infarcts is uncertain. The present retrospective study investigates whether differences are observed between patients with and without seizures following a lacunar stroke.

PATIENTS AND METHODS

Thirty-seven patients with seizures and a prior history of a lacunar stroke were admitted to the Ghent University Hospital during 2000 and 2005. They were compared to 205 patients, admitted between 2002 and 2004, with an acute lacunar stroke and without epileptic spells on follow-up. Nine out of the 37 patients with seizures and 48 out of the 205 without seizures had a history of recurrent strokes.

RESULTS

No differences in vascular risk factors, distribution and frequency of the lacunes, degree of severity of the white matter changes and outcome were observed. On the Mini-Mental State Examination moderate to severe cognitive disturbances were observed in the seizure group and in some patients of the non-seizure group.

CONCLUSIONS

In the present study we found no evidence that seizures are directly induced by lacunar infarcts. The seizures appear to be part of a more global ongoing cerebral disorder probably leading to cognitive impairment.

Magnetic Resonance Imaging after Seizures in Patients with an Ischemic Stroke

BACKGROUND

Seizures related to ischemic strokes are harmful. Their pathogenesis is not very well understood. The present study investigates whether diffusion-weighted imaging (DWI) can detect if those seizures are due to recurrent infarction or responsible for secondary ischemic changes.

PATIENTS AND METHODS

DWI was obtained within 8 days in 60 patients with seizures (7 early and 53 late onset) related to an ischemic stroke.

RESULTS

In 30 patients, positive DWI with decreased apparent diffusion coefficient was found. In 11 patients with late-onset seizures, the DWI showed a positive rim, surrounding the old infarct, while in 12 patients a large positive zone corresponding to a new infarct was observed. All 7 patients with early-onset seizures had positive DWI corresponding to the establishing infarct. A large positive zone on DWI was mainly observed in cardioembolic stroke.

CONCLUSIONS

The positive rim around the old infarct can be considered as cytotoxic edema. Recurrent acute infarction, mainly of cardioembolic origin, seems to be a significant cause of so-called late-onset seizures, making the subdivision into early- and late-onset seizures arbitrary.

EEG Findings after a Cerebral Territorial Infarct in Patients Who Develop Early- and Late-Onset Seizures

BACKGROUND

EEG findings are generally not considered to be very helpful for the diagnosis of poststroke seizures.

PURPOSE

This retrospective study investigates the EEG characteristics in patients who develop seizures after a cerebral territorial infarct.

PATIENTS AND METHODS

The study population consisted of 110 patients with seizures after a cerebral territorial infarct (12 with early- and 98 with late-onset seizures) and 275 without. All 110 patients had an interictal EEG after their first seizure. The EEG patterns after the stroke were compared between those available from 69 patients who developed seizures and those from 275 who did not. Also the EEG patterns after the seizure (n = 110) were compared to those in the poststroke group without subsequent seizures.

RESULTS

Periodic lateralized epileptic discharges (PLEDs) on the EEG after stroke were only found in 5.8% of the patients with early- and late-onset seizures. They were absent in the stroke group without seizures. Frontal intermittent rhythmic delta activities (FIRDAs) were observed in 24.6% of the seizure group, compared to 1.1% in the control group. Diffuse slowing occurred also significantly more often in the former (21.7%) compared to the latter group (5.1%). Normal EEG findings were seen in 53.8% of the stroke patients without seizures, compared to 8.5% in those with seizures. The incidence of focal slowing was the same in both groups. Similar findings were observed when comparing the EEG patterns of the patients after the first poststroke seizure to those of the stroke group without subsequent seizures. In patients with early-onset seizures, PLEDs or FIRDAs were present in 25% each. FIRDAs and diffuse slowing were significantly more frequently observed on the poststroke EEGs of patients who developed late-onset seizures.

CONCLUSIONS

FIRDAs, PLEDs and diffuse slowing are the most frequent EEG findings in patients with early-onset seizures. Patients with FIRDAs and diffuse slowing on the poststroke EEG have a high risk to develop late-onset seizures, while the chance is reduced in those with normal EEG findings.

Delayed transient worsening of neurological deficits after ischaemic stroke

BACKGROUND

Although the causes of stroke recurrence are well known, no particular study deals with the specific issue of late-onset transient worsening of the neurological deficit (TWND) after an ischaemic stroke.

PATIENTS AND METHODS

In this retrospective study the aetiology of the TWNDs in 101 patients was compared to the causes of transient ischaemic attacks (TIAs) in 115 patients. All patients had a full cardiovascular and neuroimaging examination according to current guidelines. An electroencephalogram (EEG) was performed when necessary. The diagnosis of inhibitory seizures was retained when the EEG showed periodic lateralized epileptiform discharges or intermittent rhythmic delta activities, or when the patient developed typical seizures afterwards.

RESULTS

Arterial hypertension and diabetes were more prevalent vascular risk factors in TWND patients. Small-vessel disease and inhibitory seizures were a more frequent cause of TWNDs than of TIAs. Extracranial large-vessel disease predominates in TIA patients. The global prevalence of cardiac diseases as cause of TIAs and TWNDs was the same, although severe ulcerous plaques of the aortic arch and patent foramen ovale with atrial septum aneurysm occurred more frequently in TWND patients.

CONCLUSIONS

The most frequent causes of late-onset TWNDs were different from those of TIAs. Apart from repeated neuroimaging of the brain, exhaustive cardiac investigations and EEG are mandatory in TWND patients.

Vascular cognitive impairment in patients with late-onset seizures after an ischemic stroke

BACKGROUND

Cognitive impairment and seizures are both common conditions in patients with cerebrovascular disease.

PURPOSE

The present study investigates whether the occurrence of late-onset seizures, following an ischemic stroke, contributes to vascular cognitive impairment.

PATIENTS AND METHODS

The mean Mini-Mental State Examination (MMSE) and the median modified Rankin (mR) scores were compared between 125 patients who developed late-onset seizures (66 with a single seizure and 59 with repeated seizures or epilepsy) following an ischemic stroke and 125 patients who did not during, at least, a 2-year follow-up.

RESULTS

There were no differences in age, gender, etiology and degree of neurological impairment on admission for their stroke between the groups with and without seizures. Although the mean MMSE score was similar between both groups the median mR score was significantly higher in the seizure patients. Comparing the patients with a single seizure to the non-seizure ones showed the same results. On the other hand, comparison of the patients with epilepsy to the non-seizure group revealed, in addition to the higher median mR score, a significantly lower mean MMSE score in the former group.

CONCLUSION

Repeated seizures following an ischemic stroke promote vascular cognitive impairment.