Frequency and characteristics of early seizures in Chinese acute stroke

Incidence and risk factors of post-stroke seizures and epilepsy: systematic review and meta-analysis

OBJECTIVE

Due to variability in reports, the aim of this meta-analysis was to evaluate the incidence and risk factors of post-stroke early seizures (ES) and post-stroke epilepsy (PSE).

METHODS

The MEDLINE, EMBASE and Web of Science databases were searched for post-stroke ES/PSE articles published on any date up to November 2020. Post-stroke ES included seizures occurring within 7 days of stroke, and PSE included at least one unprovoked seizure. Using random effects models, the incidence and risk factors of post-stroke ES and PSE were evaluated. The study was retrospectively registered with INPLASY (INPLASY2023100008).

RESULTS

Of 128 included studies in total, the incidence of post-stroke ES was 0.07 (95% confidence interval [CI] 0.05, 0.10) and PSE was 0.10 (95% CI 0.08, 0.13). The rates were higher in children than adults. Risk factors for post-stroke ES included hemorrhagic stroke (odds ratio [OR] 2.14, 95% CI 1.44, 3.18), severe strokes (OR 2.68, 95% CI 1.73, 4.14), cortical involvement (OR 3.09, 95% CI 2.11, 4.51) and hemorrhagic transformation (OR 2.70, 95% CI 1.58, 4.60). Risk factors for PSE included severe strokes (OR 4.92, 95% CI 3.43, 7.06), cortical involvement (OR 3.20, 95% CI 2.13, 4.81), anterior circulation infarcts (OR 3.28, 95% CI 1.34, 8.03), hemorrhagic transformation (OR 2.81, 95% CI 1.25, 6.30) and post-stroke ES (OR 7.24, 95% CI 3.73, 14.06).

CONCLUSION

Understanding the risk factors of post-stroke ES/PSE may identify high-risk individuals who might benefit from prophylactic treatment.

Seizures after percutaneous endoscopic lumbar discectomy: A case report

RATIONALE

Percutaneous endoscopic lumbar discectomy (PELD) is a minimally invasive technique for removing nucleus pulposus and achieving neural decompression via a posterolateral approach. PELD is known to have a very low rate of complications during the perioperative period. Although quite rare, seizures can occur in patients undergoing PELD.

PATIENT CONCERNS

A 58-year-old man with severe low back pain underwent the PELD procedure under general anesthesia. During the recovery phase after general anesthesia, the patient developed a tonic-clonic seizure. Two additional episodes occurred subsequently.

DIAGNOSES

Bilateral disc swelling indirectly supports the diagnosis of intracranial hypertension.

INTERVENTIONS

Midazolam and propofol were administered to control seizures. 1.0 g phenobarbital sodium was administered by intravenous injection. Ten milligrams of furosemide and 250 mL of mannitol (20%) were prescribed sequentially. Two hundred milligrams of hydrocortisone and an ice bag were used to protect the brain. Urapidil, metoprolol, and nicardipine were intermittently used to control his blood pressure. A sustained release of sodium valproate was administered and continued prophylactically for 4 weeks.

OUTCOMES

No further seizures were recorded and the patient recovered well.

LESSONS

We conclude that total volume of fluid used for irrigation was considered a possible cause of seizure. This case illustrates the fact that irrigation should be performed cautiously in PELD procedure. And anesthesiologists should be familiar with the management strategies of perioperative acute seizures.

Priority Nursing Interventions Caring for the Stroke Patient

Nearly 20% of all patients with ischemic stroke will require care in an intensive care unit (ICU), particularly those who have received intravenous alteplase or endovascular therapy. Prioritizing nursing intervention and intensive care monitoring can improve patient outcomes and reduce disability. A collaborative interdisciplinary team approach best facilitates the ICU care of an acute stroke patient.

Incidence and management of seizures after ischemic stroke

Objective:

We conducted a meta-analysis of the incidence of early and late seizures following ischemic stroke as well as a systematic review of their pharmacologic treatment.

Methods:

Observational studies that reported incidence of seizures following ischemic stroke and those that reported treatment response to any particular antiepileptic drugs (AEDs) were included. Risk of bias was assessed by predefined study characteristics. Random effects meta-analysis was conducted for all studies where data were available for the incidence of early and late stroke-related seizures. Heterogeneity was measured with I2 statistic and sensitivity analyses were performed using prespecified variables. A qualitative synthesis of studies reporting use of AEDs for stroke-related seizures was performed.

Results:

Forty-one studies from 10,554 articles were identified; 35 studies reported incidence of stroke-related seizures and 6 studies reported effects of specific AEDs. Most studies were of low to moderate quality. Rate of early seizures was 3.3% (95% confidence interval 2.8%–3.9%, I2 = 92.8%), while the incidence of late seizures or epilepsy was 18 per 1,000 person-years (95% confidence interval 1.5–2.2, I2 = 94.1%). The high degree of heterogeneity could not be explained from the sensitivity analyses. For management of stroke-related seizures, no single AED was found to be more effective over others, though newer AEDs were associated with fewer side effects.

Conclusions:

The burden of stroke-related seizures and epilepsy due to ischemic stroke is substantial. Further studies are required to determine risk factors for epilepsy following ischemic stroke and optimal secondary prevention.

The prognosis of acute symptomatic seizures after ischaemic stroke

OBJECTIVE

Acute symptomatic seizure (AS) after ischaemic stroke is defined as a seizure occurring ≤7 days of the stroke. There remains a lack of information on the prognosis of AS after ischaemic stroke and how it should be treated.

METHODS

We prospectively recruited patients after their incidents of ischaemic stroke from a population-based stroke registry. Stroke aetiology was defined according to Trial-of-ORG-10172 in acute-stroke treatment (TOAST). Patients were examined for any transient complete-occlusion with recanalisation (TCOR) and haemorrhagic transformation. The seizure outcomes were (1) acute clustering of seizures ≤7 days, (2) seizure recurrence associated with stroke recurrence beyond the 7-day period and (3) unprovoked seizure (US) >7 days.

RESULTS

104 patients (mean age 65 years/55% female) with AS after ischaemic stroke were identified (mean follow-up 6.17 years). Comparison of the group of patients with AS and those without seizures showed that patients with AS had significantly less large-vessel and small-vessel disease but more cardioembolisms (p<0.05) and a higher proportion of TCOR (p<0.01), multiple territory infarcts (p=0.007) and haemorrhagic transformations (p<0.01). Using Kaplan-Meier statistics, the risk of acute clustering of seizures ≤7 days was 22%, with a statistical trend for TCOR as a predictive factor (p=0.06). The risk of seizure recurrence associated with worsening/recurrence of stroke beyond 7 days was 13.5% at 2 years, 16.4% at 4 years and 18% at 8 years. Presence of >2 cardiovascular risk factors (p<0.05) and status epilepticus (P<0.05) are predictive risk factors on Cox regression model. The risk of US was 19% at 2 years, 25% at 4 years and 28% at 8 years with epileptiform EEG as a predictive factor (p<0.05).

CONCLUSIONS

Seizure recurrence following AS after ischaemic stroke may appear as acute clustering. Afterwards, seizures may occur as often with a recurrent stroke as without one within 4.2 years. We recommend the use of antiepileptic agents for up to 4 years if the underlying stroke aetiology cannot be fully treated.

Early seizures in acute stroke

Early seizures (ES) may complicate the clinical course of patients with acute stroke. The aim of this study was to assess the frequency and the predictive factors for early seizures as well the clinical outcome in patients with first-ever stroke. A total of 352 consecutive patients with first-ever stroke, admitted to our department, were included in this retrospective study. Early seizures were defined as seizures occurring within 7 days from acute stroke. Patients with history of epilepsy were excluded. About 47 patients (13%) had early seizure, and 8 had a status epilepticus. We had 28 women and 19 men. The mean age was 71.6 ± 14.6. They were significantly more common in patients with cortical involvement, severe and large stroke, and in patient with cortical associated hemorrhage. ES were associated with an increase in adverse outcome (mortality and disability). Early seizures occurred in about 13% of patients with acute stroke. In these patients hemorrhagic transformation is a predictive factor for ES. ES seem to be associated with a worse outcome after acute stroke.

Seizures in the acute stroke setting

Stroke is one of the leading causes of long-term disability. One in six people in the world will suffer a stroke in their lifetime, with the annual incidence about 117 per 100,000 person-years in developing countries. It has also been shown to be the cause of 10-15% of epilepsies, more prevalent in patients above 60 years of age. The incidence of early seizures in acute stroke ranges 3-33%, with 50-78% of the seizures occurring within the first 24 hours. Occurrence of seizures within 24 hours of stroke is associated with higher 30-day mortality, which may be a reflection of severe neuronal damage. Alteration in intracellular ion concentrations and hyper-excitability are thought to be etiologies for early seizures in acute stroke, and the increased stress on already vulnerable tissues may result in worsening of stroke symptoms. Early detection of seizures and subsequent effective treatment can prevent additional metabolic burden and damage to the blood-brain barrier, which may improve recovery and overall outcome. Clinical seizures can be recognized readily at bedside and lead to prompt medical intervention. In contrast, electrographic seizures with subtle or no clinical sign and non-convulsive status epilepticus (NCSE) may escape clinical observation and be left untreated. With the use of continuous electroencephalogram monitoring (cEEG), patients with electrographic seizures can be better identified and medically treated more quickly. In addition to electrographic seizures, the presence of isolated and periodic epileptiform patterns on electroencephalogram (EEG) suggests the need for medical treatment since up to 75% of these patients have been found to develop early post-stroke seizures. Newer anti-epileptic medications with intravenous formulation, together with traditional regimen and barbiturate, have shown promise in controlling early post-stroke seizures and possibly improving outcome.

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.

Prognostic value of early epileptic seizures on mortality and functional disability in acute stroke: the Dijon Stroke Registry (1985-2010)

We aimed to evaluate the prognostic value of early epileptic seizures after stroke. All consecutive patients with a first-ever stroke were prospectively identified within the population of Dijon, France, thanks to a population-based registry, from 1985 to 2010. Early epileptic seizures were defined as seizures occurring within 14 days after stroke onset. Outcomes were 1-month and 1-year mortality, and severe functional handicap at discharge. Of the 4,411 stroke patients included, data about seizures were available in 4,358 (98.8, 53.5 % women, mean age, 74.1 ± 14.8 years). Among these patients, 134 (3.1 %) had early seizures. Stroke patients with early seizures differed from those without seizures, as there was a higher proportion of hemorrhagic stroke, higher blood glucose level at admission, smoking status, and more frequent impaired. Higher risks of 1-month and 1-year mortality in patients with early seizures (unadjusted HR 1.45, 95 % CI 1.00-2.10; HR = 1.59, 95 % CI 1.21-2.09, respectively) disappeared (HR 0.71, 95 % CI 0.49-1.08 and HR 0.85, 95 % CI 0.64-1.17) after adjustment for stroke severity and other confounding factors. Early seizures were associated with severe handicap in unadjusted analyses (OR 2.07, 95 % CI 1.46-2.95) but the association was no longer significant after multivariable adjustment (OR 1.12, 95 % CI 0.69-1.83). Early epileptic seizures were not associated with higher risks of mortality at 1 month and 1 year or with unfavorable functional outcome after acute stroke. The adverse effects of epileptic seizures may not be distinguishable from stroke severity, which is strongly related to epileptic seizures.

Early seizures in first-ever acute stroke patients in India: incidence, predictive factors and impact on early outcome

BACKGROUND AND PURPOSE

Stroke-associated early seizures (ES) often complicate the initial course of acute stroke. This study intended to estimate the rate of and the predictive factors for ES and the impact of ES on the clinical outcome in patients with first-ever acute stroke.

MATERIALS AND METHODS

Consecutive patients with first-ever acute stroke admitted in the Department of Medicine from June 2010 to December 2011 were prospectively included. ES were defined as seizures occurring within 7 days from acute stroke. Patients with history of epilepsy, transient ischaemic attack, subarachnoid haemorrhage and cerebral venous thrombosis were excluded. Clinical outcomes were measured under the subheadings of mortality and disability at discharge, according to modified Rankin score.

RESULTS

Of the 441 (56.92% male patients, median age 55 years, 49.43% had haemorrhagic stroke) patients, 79 (17.91%, 95% confidence interval (CI): 14.61-21.78%) suffered from ES. At discharge, 37.64% were disabled, and 19.5% were dead. In multivariate analysis, alcoholism, NIHSS at admission, haemorrhagic stroke and cortical location were significant predictors of ES. Thirty-day mortality was predicted by NIHSS at admission [hazard ratio (HR): 1.14, 95% CI: 1.11-1.18, P < 0.001], history of hypertension (HR: 3.79, 95% CI: 2.1-6.85, P < 0.001), history of alcoholism (HR: 2.43, 95% CI: 1.49-3.95, P < 0.001) and early seizure (HR: 2.58, 95% CI: 1.54-4.34, P = 0.001).

CONCLUSIONS

Early seizures occurred in about 18% acute stroke patients. Alcoholism, haemorrhagic stroke, cortical and severe strokes predict development of ES. ES are an independent important risk factor for early mortality.

The increased expression of metabotropic glutamate receptor 5 in subventricular zone neural progenitor cells and enhanced neurogenesis in a rat model of intracerebral hemorrhage

The metabotropic glutamate receptor 5 (mGluR5) is closely relative to the proliferation, survival, and differentiation of neural progenitor cells (NPCs). This study primarily examined the mGluR5 expression of NPCs in subventricular zone (SVZ) and the effects of mGluR5 on neurogenesis to intracerebral hemorrhage (ICH) rat. The experiment was designated as the following: (1) The ICH model was established by collagenase infusion into the right striatum of the rats, and the brain tissue was collected to assess the expression of mGluR5 in SVZ NPCs. (2) The rat brains were sampled for immunostaining of doublecortin (DCX) and 5-bromo-2'-deoxyuridine (BrdU) to examine the effects of the (R,S)-2-chloro-5-hydroxyphenylglycine (CHPG) on neurogenesis. (3) Behavioral testing was carried out to evaluate the effects of CHPG on neurofunctional recovery. The results of Western blot analysis showed that mGluR5 levels in the ipsilateral SVZ increased as early as at 3 days after ICH, peaked at 14 days. The change of mGluR5 mRNA level in the ipsilateral SVZ was generally similar to the pattern of Western blot analysis. The immunostaining also demonstrated that some nestin-positive cells were co-expressed with mGluR5. The injection of CHPG into ipsilateral ventricle increased DCX levels both in the ipsilateral striatum (STR) and the peri-lesion area of the striatum (PLA). Meanwhile, a significant difference in behavioral score was presented at 28 days after ICH between the CHPG-treated rats and the vehicle-treated or the non-treated rats. Our results demonstrated for the first time that the increased expression of mGluR5 in SVZ NPCs occurred in ICH rat. The CHPG promoted the neurogenesis and improved neurofunctional symptom induced by ICH. These results suggested that the increased expression of mGluR5 on NPCs in SVZ may play an important role in neurogenesis in ICH rat.

Nicardipine, a calcium antagonist, does not aggravate intracerebral haemorrhage in an intracerebral haemorrhage model in rats

Despite controversy over their safety in patients with intracerebral haemorrhage, calcium antagonists are widely used in the treatment of hypertensive emergencies. Here, we investigated the effects of nicardipine on haematoma size and neurological deficit in a rat model of collagenase-induced intracerebral haemorrhage. Injection of collagenase (0.014 U) into the striatum induced haematoma (19.9 ± 3.4 mm3) in the striatum and brain oedema. Drugs were infused from 30 min after collagenase injection for 3 h under conscious conditions. Nicardipine intravenously at 0.1, 1 and 10 μg kg−1 min−1 affected neither haematoma size nor the degree of brain oedema. Nicardipine at these doses provided a stable and dose-dependent decrease in mean blood pressure of 6%, 13% and 33%, respectively, with an increase in heart rate that was apparently caused reflexively. Further, nicardipine did not aggravate the neurological deficits in these intracerebral haemorrhage rats, primarily forearm flexion behaviour on suspension by the tail and circling behaviour. These results indicate that nicardipine infusion stably decreased blood pressure without affecting intracerebral haemorrhage in an intracerebral haemorrhage model in rats.

Ischaemic stroke in adults and epilepsy

Stroke is an important cause of symptomatic epilepsy especially in the elderly. Seizures in the setting of stroke will furthermore worsen the prognosis of stroke. Studies show that the frequency of seizures in stroke ranges between 2.3% and 14%. Typically early seizures are defined as those that occur within 14 days of the stroke, and later seizures those that occur after this period. A number of risk factors have been identified like cortical involvement, size of the infarct and stroke severity. Status epilepticus can be a presenting symptom of acute stroke and can lead to increased mortality. Early seizures are risks for recurrent seizures though not for the development of epilepsy but late seizures do carry a higher risk. There are no clear cut guidelines for the treatment of seizures in stroke and hence treatment needs to be initiated in the context of the patient. The presence of co morbid conditions and the use of other drugs also complicate antiepileptic therapy, and the risk of drug interactions is a particular hazard in elderly patients on multiple co medication. Although hemorrhagic and ischaemic stroke can both result in epilepsy, this review focuses primarily the association of epilepsy and ischaemic stroke.

Tracking of neural stem cells in rats with intracerebral hemorrhage by the use of 3T MRI

OBJECTIVE

To access the feasibility of clinically available 3T MRI to detect the migration of labeled neural stem cells (NSCs) in intracerebral hemorrhage (ICH) in a rat model.

MATERIALS AND METHODS

The ethics committee of our institution approved this study. ICH was induced by the injection of collagenase type IV into the right striatum of ten Sprague-Dawley rats. Human NSCs conjugated with Feridex (super-paramagnetic iron oxide: SPIO) were transplanted into the left striatum one week after ICH induction. MRI was performed on a 3T scanner during the first, second, third, fourth, and sixth weeks post-transplantation. MRI was obtained using coronal T2- and T2*-weighted sequences. Two rats were sacrificed every week after in vivo MRI in order to analyze the histological findings.

RESULTS

ICH in the right striatum was detected by MRI one and two weeks after transplantation without migration of the NSCs. There was no migration of the NSCs as seen on the histological findings one week after transplantation. The histological findings two weeks after transplantation showed a small number of NSCs along the corpus callosum. On MRI three weeks after transplantation, there was a hypointense line along the corpus callosum and decreased signal intensity in the right periventricular region. Histological findings three weeks after transplantation confirmed the presence of the hypointense line representing SPIO-labeled NSCs. MRI four and six weeks after transplantation showed a hypointense spot in the right periventricular region. The histological findings four and six weeks after transplantation showed the presence of prominent NSCs in the right periventricular region.

CONCLUSION

3T MRI can detect the migration of NSCs in rats with ICH along the corpus callosum. Therefore, 3T MRI could be feasible for detecting the migration of NSCs in the clinical setting of stem cell therapy.

Poststroke epilepsy in the Copenhagen stroke study: incidence and predictors

Poststroke epilepsy (PSE) is a feared complication after stroke and is reported in 3% to 5% of stroke survivors. In this study we sought to identify incidence and predictors of PSE in an unselected stroke population with a follow-up period of 7 years. The study was community-based and comprises a cohort of 1197 consecutively and prospectively admitted patients with stroke. Patients were followed up for 7 years. We defined PSE as recurrent epileptic seizures with onset after stroke and requiring antiepileptic prophylaxis. PSE was related to clinical factors (age, sex, onset stroke severity, lesion size on computed tomography scans, stroke subtype, localization, stroke risk factor profile, and early seizures) in univariate analyses. Independent predictors of PSE were identified through multiple logistic regression analyses. Overall, 38 patients (3.2%) developed PSE. Univariately, PSE was associated with younger age, intracerebral hemorrhage, and larger lesions. PSE was less frequently associated with atrial fibrillation and ischemic heart disease. In the final multiple regression model for the dependent variable PSE, independent predictors were younger age (odds ratio [OR] 1.7/10 years; 95% confidence interval [CI] 1.3-2.1), onset stroke severity (OR 1.3-/10-point decrease; 95% CI 1.0-1.6), lesion size (OR 1.2-/10-mm enlargement; 95% CI 1.0-1.3), intracerebral hemorrhage (OR 3.3; 95% CI 1.3-8.6), and early seizures (OR 4.5; 95% CI 1.3-16.0). We conclude that PSE occurs in about 3% of all patients with stroke within 7 years after stroke. Age, intracerebral hemorrhage, lesion size, increasing stroke severity, and early seizures are independent predictors of PSE.

[Seizure and epilepsy after stroke]

Seizures and status epilepticus may be an early (<7-14 days) or late (>14 days) complication of acute stroke. Epilepsy, defined by at least two unprovoked epileptic seizures, may also be a late complication. Several risk factors have been identified for early and late seizures. Early seizures are more frequent in severe and disabling ischemic strokes, hemorrhagic strokes and those with cortical involvement. The risk of epilepsy is higher for patients with early seizures or cortical infarctions and in severely handicapped patients. Overall, approximately 4% of patient with an acute stroke will have at least one seizure in the early or late period, and half of them will develop epilepsy. Neither early nor late seizures appear to have a significant impact on mortality, although status epilepticus remains a life-threatening and often fatal event. The decision whether to start antiepileptic treatment after a first seizure or wait for a recurrence remains controversial. Risk of drug interactions and adverse effects in stroke patients must be kept in mind when prescribing antiepileptic drugs.

Seizure development after stroke

Although there have been many studies on seizures following stroke, there is still much we do not know about them. In this study, we evaluated the characteristics of seizures in stroke patients. There were 2267 patients with a first-ever stroke, and after excluding 387 patients, 1880 were available for analysis. Of these 1880 patients, we evaluated 200 patients with seizures and 400 patients without seizures. We investigated the seizures according to age, gender, stroke type, the aetiology of ischaemic stroke and the localisation of the lesion. The seizures were classified as early onset and late onset and the seizure type as partial, generalised or secondarily generalised. Seizures occurred in 200 (10.6%) of 1880 strokes. The number of patients with seizures were 138 (10.6%) in ischaemic stroke group and 62 (10.7%) in haemorrhagic stroke group. Patients with ischaemic strokes had 41 embolic (29.7%) and 97 thrombotic (70.3%) origin, and these were not statistically significant in comparison with controls. Cortical involvement for the development of seizures was the most important risk factor (odds ratios = 4.25, p < 0.01). It was concluded that embolic strokes, being younger than 65 years old, and cortical localisation of stroke were important risks for developing seizures.

Recovery from stroke: differences between subtypes

The objective of this study was to compare the differences in patterns of recovery and incidence of medical complications in hemorrhagic and ischemic stroke patients admitted for rehabilitation, using a retrospective case series design. It was set in three tertiary care facilities in London, Ontario, Canada. Eight-hundred-and-nineteen consecutive patients, admitted from 1997 to 2001 for rehabilitation following cerebrovascular event, were reviewed. The main outcome measures were: age, length of hospital stay, time to admission, medical complications, ambulation status and functional independence measure scores on both admission and discharge. The results showed that 110 patients had strokes that were hemorrhagic, while 709 were ischemic. The hemorrhagic stroke patients were younger (66 vs. 70 years, P=0.001) and were admitted later post stroke onset (30 vs. 18 days, P<0.0001). They had a higher incidence of pneumonia (6.4 vs. 2.7%, P=0.04), pulmonary emboli (3.6 vs. 0.07%, P=0.006) and wheelchair ambulation on admission (53 vs. 41%, P=0.026). There was no significant difference in incidence of seizures or wheelchair ambulation on discharge, length of rehabilitation stay or Functional Independence Measure scores on both admission and discharge. In conclusion, hemorrhagic stroke patients took longer than ischemic stroke patients to enter into rehabilitation, and were more inclined to experience ambulatory impairments and develop medical complications.

Influence of pre-existing dementia on the risk of post-stroke epileptic seizures

BACKGROUND

Seizures occur in 10% of stroke patients, but their predictors have not been clearly identified. Pre-existing dementia is present in 12-16% of stroke patients and, at the community level, patients with dementia have increased risk of seizures. However, the question of whether pre-existing dementia is associated with a higher risk of seizures after stroke has never been studied.

AIM

To evaluate whether pre-existing dementia is associated with an increased risk of seizures after stroke.

METHODS

The study was conducted on 202 consecutive stroke patients recruited to the Lille stroke/dementia study (97 men; median age, 75 years; range, 42-100). Pre-stroke cognitive functions were evaluated using the Informant Questionnaire on Cognitive Decline in the Elderly, with a cutoff value of 104 for the diagnosis of dementia. Seizures were defined as early seizures when occurring within seven days of stroke onset, and as late seizures when occurring more than seven days after stroke.

RESULTS

Of 202 patients, 33 (16.3%) met the criteria for pre-existing dementia, and 11 (5.4%) developed early seizures. During 289 person-years of follow up, 14 patients developed late seizures, resulting in an incidence rate of 4.8 new cases/100 person-years. Pre-existing dementia was not associated with the occurrence of early seizures, but was independently associated with the occurrence of late seizures (adjusted odds ratio, 4.66; 95% confidence interval, 1.34 to 16.21).

CONCLUSION

Stroke patients with pre-existing dementia have an increased risk of late seizures. Any factor increasing the risk of seizures (drugs, metabolic changes) should be avoided in these patients.

Poststroke Epilepsy

Seizures and status epilepticus can be a presenting feature of acute stroke. They may occur in its early (<7 days) clinical course or be a remote (>7 days) complication. Most seizures are single, either partial or generalised. Early and remote seizures seem to have different predictors and pathogenesis. Seizures are more frequent in severe and disabling strokes, haemorrhagic strokes and those with cortical involvement. The risk of epilepsy is higher for patients with early seizures, cortical infarctions and lobar haemorrhages and in dependent patients. Early or remote seizures do not have a significant influence on dependency or mortality, although seizures and status epilepticus can be a direct cause of death. Treatment can be started after a first or a recurrent seizure. Treatment options include phenytoin, carbamazepine, valproic acid (valproate sodium) and the new antiepileptic drugs (AEDs). New AEDs can be used to decrease the likelihood of drug interactions and adverse effects in patients who do not tolerate the classic AEDs and in treatment failures with classic AEDs. Large observational studies to define prognostic factors for poststroke seizures in specific stroke subtypes are needed. Randomised controlled trials of AED prophylaxis for acute and remote seizures are essential to improve the evidence level of current guidelines and recommendations.

Nitrones as neuroprotective agents in cerebral ischemia, with particular reference to NXY-059

Stroke is a major clinical problem, and acute pharmacological intervention with neuroprotective agents has so far been unsuccessful. Recently, there has been considerable interest in the potential therapeutic benefit of nitrone-derived free radical trapping agents as neuroprotective agents. Nitrone compounds have been shown to be beneficial in animal models of various diseases, and the prototypic compound alpha-phenyl-N-tert-butylnitrone (PBN) has been extensively demonstrated to be neuroprotective in rat models of transient and permanent focal ischemia. The nitrone radical trapping agent disodium 2,4-disulfophenyl-N-tert-butylnitrone (NXY-059) has also been shown to be neuroprotective in these models. Furthermore, it has recently been shown to improve neurological function and reduce infarct volume in a primate model of permanent focal ischemia even when given 4 hr postocclusion. While radical trapping activity is demonstrable with NXY-059 and other nitrone compounds such as PBN, this activity is weak. Arguments for and against ascribing radical trapping as the therapeutic mechanism of action are discussed. This compound is well tolerated in human stroke patients and can be administered to produce plasma concentrations exceeding those effective in animal models; crucially, at the same time, it has also been shown to be effective in animal models. NXY-059 may thus be the first compound to be examined in stroke patients using drug exposure and time to treatment that have been shown to be effective in animal models of stroke.

Amount of bleeding and hematoma size in the collagenase-induced intracerebral hemorrhage rat model

The aggravated risk on intracerebral hemorrhage (ICH) with drugs used for stroke patients should be estimated carefully. We therefore established sensitive quantification methods and provided a rat ICH model for detection of ICH deterioration. In ICH intrastriatally induced by 0.014-unit, 0.070-unit, and 0.350-unit collagenase, the amount of bleeding was measured using a hemoglobin assay developed in the present study and was compared with the morphologically determined hematoma volume. The blood amounts and hematoma volumes were significantly correlated, and the hematoma induced by 0.014-unit collagenase was adequate to detect ICH deterioration. In ICH induction using 0.014-unit collagenase, heparin enhanced the hematoma volume 3.4-fold over that seen in control ICH animals and the bleeding 7.6-fold. Data suggest that this sensitive hemoglobin assay is useful for ICH detection, and that a model with a small ICH induced with a low-dose collagenase should be used for evaluation of drugs that may affect ICH.

Effect of AMPA receptor antagonist YM872 on cerebral hematoma size and neurological recovery in the intracerebral hemorrhage rat model

[2,3-dioxo-7-(1H-imidazol-1-yl)-6-nitro-1,2,3,4-tetrahydro-1-quinoxalinyl]-acetic acid monohydrate (YM872 or zonampanel), an AMPA receptor antagonist, is in clinical development for acute ischemic cerebral infarction. Stroke patients are prone to have subsequent intracerebral hemorrhages. In order to predict potential adverse effects, YM872 was tested in a rat model with collagenase-induced intracerebral hemorrhage. The morphologically determined hematoma volumes after 24 h were compared between animal groups intravenously infused with 3600 U/kg/h heparin for 30 min, or with 20 or 40 mg/kg/h of YM872, or placebo for 4 h. Heparin enlarged hematoma volume, but neither dose of YM872 affected hematoma size. In a separate study, neurological deficits were scored at various days after intracerebral hemorrhage induction in animals with intravenous infusion for 24 h of 10 or 20 mg/kg/h YM872, or saline. The YM872 groups scored significantly better than the saline group at 14 days. These data suggest that YM872 does not exacerbate intracerebral hemorrhage and might accelerate recovery.

Seizures after aneurysmal subarachnoid hemorrhage treated with coil embolization

OBJECTIVE

We sought to determine the incidence of seizures among patients treated with endovascular coil embolization for ruptured intracranial aneurysms because data on which to base antiepileptic drug (AED) prescriptions and advice to patients regarding driving motor vehicles and other high-risk activities are currently lacking.

METHODS

We conducted a single-institute, single-operator observational study of 243 patients referred for endovascular treatment after aneurysmal subarachnoid hemorrhage. Prospective data collection was performed, and all successfully treated patients were followed. The incidence of seizures was compared with published surgical data, and logistic regression analysis of potential clinical associations was performed. Patients were followed for up to 7.7 years (mean follow-up period, 21.9 mo).

RESULTS

Ictal seizures occurred at the time of subarachnoid hemorrhage in 26 (11%) of 243 patients and correlated with middle cerebral artery aneurysm location, loss of consciousness at ictus, and AED prescription. No patients experienced periprocedural seizures during their hospitalization. Seven of 233 successfully treated patients (3%) experienced seizures more than 30 days after treatment: late seizures occurred de novo in four patients (1.7%) and in three patients (1.4%) were caused by preexisting epilepsy. Two patients (0.85%) who had de novo seizures developed epilepsy. Late seizures correlated with a history of previous seizures, the presence of a cerebrospinal fluid shunt, and the use of AEDs.

CONCLUSION

The low incidence of seizures does not justify the use of prophylactic AED therapy after aneurysmal subarachnoid hemorrhage in patients treated solely with coil embolization, nor does it justify subsequent restrictions on the driving of motor vehicles if the patient is otherwise fit to drive.

Effects of exogenous creatine on population spike amplitude and on postanoxic hyperexcitability in brain slices

In in vitro rat hippocampal slices, a short period of transient anoxia caused a lasting increase in the amplitude of the compound action potential (population spike, PS) that was evoked in CA1 by stimulation of the Schaffer collaterals. No such increase was seen over a comparable period of time in slices that were not subjected to anoxia. The appearance of such an increase was dependent on the duration of anoxia. Anoxia of 1 min duration did not cause any increase, anoxia lasting 2 min caused a nonsignificant increase, while 3 min of anoxia caused a lasting and statistically significant increase in PS amplitude. Addition of creatine, a compound that is known to afford protection against severe neuronal damage from longer periods of anoxia, prevented PS potentiation at a concentration of 10 mM, but not at a concentration of 1 mM. In addition, while 1 mM creatine by itself did not show any effect on PS amplitude of control slices, 10 mM creatine decreased PS amplitude also in such control slices, that had not been exposed to anoxia. These data demonstrate that this postanoxic hyperexcitability is caused by mechanisms that are little sensitive to the protection that in other contexts is provided by creatine. We suggest that understanding the mechanisms of postanoxic hyperexcitability may help understand the pathophysiology of the epileptic seizures that sometimes occur at the time of an ischemic stroke.

Stroke and status epilepticus: stroke type, type of status epilepticus, and prognosis

Even though stroke is known to be a common cause of status epilepticus (SE), the types of stroke or SE that may be associated are not yet clearly defined. The aims of this study were to assess the timing and type of SE in stroke patients and to observe the effects of stroke and the type of SE on the response to treatment and mortality. From May 1998 to May 2001 a total of 121 patients were admitted with SE. Among these, 30 cases (24.8%) of poststroke SE were identified and evaluated. There were 20 early-onset, and 10 late-onset SE. All stroke types were evenly distributed within the early-onset group, whereas only ischaemic stroke was found in the late-onset group. Posterior cerebral artery (PCA) infarcts were significantly more common within the latter (P: 0.0017). Nonconvulsive SE (NCS) was more frequent than convulsive SE (CS) in the early-onset group (P: 0.0352). There was a delay in the time-to-treatment for NCS compared to CS (P: 0.0007). Without, however any effect on the rate of response to first step treatment (intravenous diazepam and phenytoin; P: 0.6334). Thirteen patients died (43.3%) during hospitalisation. Disability was significantly associated with higher mortality in the early-onset group (P: 0.0201). As a conclusion, NCS seems to be an important issue in stroke, thus requiring a high degree of suspicion in an acute stroke setting to avoid further neuronal injury and morbidity.

Seizures after spontaneous supratentorial intracerebral hemorrhage

PURPOSE

To characterize seizures after intracerebral hemorrhage (ICH), evaluating the risk of occurrence and relapse, predisposing factors, and prognostic significance, and to assess the utility of antiepileptic drug (AED) therapy as used in clinical practice.

METHODS

The study sample consisted of 761 patients with spontaneous, nonaneurysmal, supratentorial ICH. Seizures were classified as immediate (within 24 h of ICH) and early (within 30 days of ICH). Baseline variables and clinical events were compared in the seizure and nonseizure group by using a multivariate regression model of failure time data.

RESULTS

Fifty-seven patients had one or more seizures. The 30-day actuarial risk of a post-ICH seizure was 8.1%. Lobar location and small volume of ICH were independent predictors of immediate seizures. Early seizures were associated with lobar location and neurologic complications, mainly rebleeding. In patients with lobar ICH, the risk of early seizures was reduced by prophylactic AED therapy. Among seizure patients, history of alcohol abuse increased the risk of status epilepticus. Immediate and early seizures were not independent predictors of in-hospital mortality.

CONCLUSIONS

Patients with ICH are exposed to a substantial risk of seizures; however, short-term mortality was not affected, and the risk of epilepsy was lower than previously thought. The likelihood of immediate seizures is influenced by factors that are inherent characteristics of ICH, whereas the chance of developing early seizures is influenced not only by certain characteristics of ICH, but also by unpredictable events. A brief period of therapy soon after ICH onset may reduce the risk of early seizures in patients with lobar hemorrhage.

Efficacy of disodium 4-[(tert-butylimino)methyl]benzene-1,3-disulfonate N-oxide (NXY-059), a free radical trapping agent, in a rat model of hemorrhagic stroke

Because free radical mechanisms may contribute to brain injury in hemorrhagic stroke, the effect of the free radical trapping agent disodium 4-[(tert-butylimino)methyl]benzene-1,3-disulfonate N-oxide (NXY-059) was investigated on outcome following intracerebral hemorrhage (ICH) in rat. ICH was induced in 20 adult rats by infusion of collagenase into the caudate-putamen. Thirty minutes later rats were treated with NXY-059 (50 mg/kg subcutaneous plus 8.8 mg/kg/h for 3 days subcutaneous delivered via implanted osmotic pumps) or saline (equivalent volumes). Magnetic resonance imaging 24 h after ICH confirmed that the hemorrhage was uniform in the two groups, and subsequent imaging at 7 and 42 days post-ICH showed that the hematoma resolved similarly in the two groups. Behavioral testing on days 1, 3, 7, 14, and 21 after ICH showed that rats treated with NXY-059 had significantly decreased neurological impairment at all times. Deficits in skilled forelimb use 4-5 weeks post-ICH, and in striatal function 6 weeks post-ICH, were not reduced by treatment with NXY-059. Treatment with NXY-059 significantly reduced the neutrophil infiltrate observed 48 h post-hemorrhage in the vicinity of the hematoma, and the number of TUNEL-positive cells 48 h post-hemorrhage at the hematoma margin. However, by 6 weeks there were no differences in neuronal densities in treated and control rats.

Effect of FK-506 on inflammation and behavioral outcome following intracerebral hemorrhage in rat

Beginning 15 min after induction of intracerebral hemorrhage (ICH) by intrastriatal administration of collagenase, rats were treated intramuscularly with FK-506 (3 mg/kg) or with vehicle. Treatment was repeated daily for 7 days. MR imaging 1, 7, and 28 days post-ICH showed that treatment did not affect hematoma size or its subsequent resolution. Two days post-ICH, neutrophil infiltration around the hematoma was decreased in the FK-506-treated rats, as was the number of TUNEL-positive cells at the edge of the hematoma and in the peripheral region. The decreased inflammatory response was accompanied by functional improvement in the treated rats. The neurological deficit induced by the ICH (beam walking ability, postural reflex, spontaneous circling) was significantly decreased from 3 to 21 days post-ICH by treatment with FK-506. Skilled use of the forelimb ipsilateral to the ICH was improved and sensory neglect of the same limb was decreased 8-9 weeks post-ICH in rats treated with FK-506. However, neuronal loss assessed 9 weeks post-ICH was not different in the treated and untreated rats.

[Cerebrovascular disease in children: I. Epileptic manifestations]

Seizures may occur as a complication of cerebrovascular disease (CVD) and its prevalence, clinical presentation, risk factors and evolution have been reported by few authors. We evaluated 39 children with CVD and analyzed the association with seizures. Seizures occurred in 24 (61.5%) patients and were classified as partial (29.2%), generalized (54.2%) and secondarily generalized (16.6%). Infants had a significantly higher prevalence of seizures (p = 0.0362) than children at other ages. Cortical localization was associated with a significantly higher prevalence of seizures (p = 0.0101). There were no differences between ischemic and hemorrhagic strokes. Fourteen patients had no seizures after the acute phase of the CVD, the 2 previously epileptic patients had their seizures controlled with antiepileptic drugs, 3 developed epilepsy, 2 died during the acute phase and in 3 patients there was not enough time yet to make a clear diagnosis of epilepsy.

Acute symptomatic seizures - incidence and etiological spectrum: a hospital-based study from South India

We analysed the incidence and etiological spectrum of acute symptomatic seizures in 2531 patients with seizure disorder, both in-patients and out-patients, seen in a university hospital in South India. Seizure(s) occurred in close temporal association with an acute systemic, metabolic, or toxic insult or in association with an acute central nervous system (CNS) insult in 22.5% of patients. Of the 572 patients, 8% could be grouped under the International League Against Epilepsy (ILAE) category 4.1 and 92% under category 1.2. The seizure type was generalized in all the patients included in category 4.1 and 78% of patients grouped in category 2.1 had simple or complex partial seizure(s) with or without secondary generalization. Sixteen (3%) patients developed status epilepticus during the acute phase of illness and 7% of patients had only single seizure. Infections of the central nervous system (CNS) and single CT enhancing lesions (SCTEL) together accounted for 77% of the provoking factors in patients grouped under category 2.1. These two etiological factors together accounted for 95% of etiologies in patients aged under 16 years. SCTEL and neurocysticercosis together accounted for 67% of the provoking factors. In 14% of patients cerebrovascular diseases were the etiological factors and 60% of the patients were aged over 40 years. In patients with cerebrovascular diseases, aged under 40 years, cortical sinovenous thrombosis accounted for 37%. SCTEL was the provoking factor in 61% of patients with isolated seizure. Infections of CNS and SCTEL together accounted for 62.5% of etiological factors for status epilepticus. This study illustrates that the etiological spectrum of acute symptomatic seizures in this part of the world is different from that described from developed countries and CNS infections account for a significant number of cases.