Predictors of Seizure Recurrence after Acute Symptomatic Seizures in Ischemic Stroke Patients

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

OBJECTIVE

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

METHODS

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

RESULTS

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

SIGNIFICANCE

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

Outcomes and predictors of seizure recurrence in post-stroke epilepsy, a retrospective hospital-based study

BACKGROUND

The occurrence of seizures following a stroke is a well-recognized complication associated with a significant increase in morbidity and mortality. Despite the numerous studies examining outcomes and risk factors related to post-stroke seizures (PSS), there remains a lack of clarity regarding the clinical characteristics, treatment, and PSS recurrence (PSSR) rates in patients experiencing their initial episode of PSS.

PURPOSE

This study aimed to determine the risk factors for developing recurrent seizures after first PSS and their effects on functional outcomes and mortality.

METHODS

All patients underwent an electroencephalography (EEG) and were monitored for a minimum of 24 months following the first PSS. The primary endpoint was the recurrence of seizures. Predictive factors for PSSR were determined by using the Cox-proportional hazards model, and the cumulative latency of recurrence at 90, 180, 360, and 720 days was estimated using Kaplan-Meier analysis.

RESULTS

Seizure recurred in 36.8% (39/106). Significant association of PSSR was noted with female gender, use of older anti-seizure medications (ASMs) (p<0.001), EEG findings as focal slow wave activity (p<0.001), Ictal epileptiform abnormalities (p=0.015), status epilepticus (p=0.015), and with severe disability (p=0.008). However, multivariate cox-proportional hazards model showed significant association of female gender (HR=3.28; 95% CI: 1.42-7.58; p=0.006). Hazard ratio (HR) was increased with older ASMs use, focal aware seizure types, Ictal EAs, and periodic discharges on EEG; though, statistically significant.

CONCLUSION

Factors such as the type of ASMs, EEG findings, and seizure type were significantly linked to PSSR. Female gender was the only independent predictor established. Additionally, significant functional decline was reported with recurrence.

Prognosis and management of acute symptomatic seizures: a prospective, multicenter, observational study

BACKGROUND

Acute symptomatic epileptic seizures are frequently seen in neurocritical care. To prevent subsequent unprovoked seizures, long-term treatments with antiseizure medications are often initiated although supporting evidence is lacking. This study aimed at prospectively assessing the risk of unprovoked seizure relapse with respect to the use of antiseizure medications. It was hypothesized that after a first acute symptomatic seizure of structural etiology, the cumulative 12-month risk of unprovoked seizure relapse is ≤ 25%.

METHODS

Inclusion criteria were age ≥ 18 and acute symptomatic first-ever epileptic seizure; patients with status epilepticus were excluded. Using telephone and mail interviews, participants were followed for 12 months after the acute symptomatic first seizure. Primary endpoint was the occurrence and timing of a first unprovoked seizure relapse. In addition, neuro-intensivists in Germany were interviewed about their antiseizure treatment strategies through an anonymous online survey.

RESULTS

Eleven of 122 participants with structural etiology had an unprovoked seizure relapse, resulting in a cumulative 12-month risk of 10.7% (95%CI, 4.7%-16.7%). None of 19 participants with a non-structural etiology had a subsequent unprovoked seizure. Compared to structural etiology alone, combined infectious and structural etiology was independently associated with unprovoked seizure relapse (OR 11.1; 95%CI, 1.8-69.7). Median duration of antiseizure treatment was 3.4 months (IQR 0-9.3). Seven out of 11 participants had their unprovoked seizure relapse while taking antiseizure medication; longer treatment durations were not associated with decreased risk of unprovoked seizure relapse. Following the non-representative online survey, most neuro-intensivists consider 3 months or less of antiseizure medication to be adequate.

CONCLUSIONS

Even in case of structural etiology, acute symptomatic seizures bear a low risk of subsequent unprovoked seizures. There is still no evidence favoring long-term treatments with antiseizure medications. Hence, individual constellations with an increased risk of unprovoked seizure relapse should be identified, such as central nervous system infections causing structural brain damage. However, in the absence of high-risk features, antiseizure medications should be discontinued early to avoid overtreatment.

Interictal epileptiform discharges as a predictive biomarker for recurrence of poststroke epilepsy

Poststroke epilepsy is a major ischaemic/haemorrhagic stroke complication. Seizure recurrence risk estimation and early therapeutic intervention are critical, given the association of poststroke epilepsy with worse functional outcomes, quality of life and greater mortality. Several studies have reported risk factors for seizure recurrence; however, in poststroke epilepsy, the role of EEG in predicting the risk of seizures remains unclear. This multicentre observational study aimed to clarify whether EEG findings constitute a risk factor for seizure recurrence in patients with poststroke epilepsy. Patients with poststroke epilepsy were recruited from the PROgnosis of POst-Stroke Epilepsy study, an observational multicentre cohort study. The enrolled patients with poststroke epilepsy were those admitted at selected hospitals between November 2014 and June 2017. All patients underwent EEG during the interictal period during admission to each hospital and were monitored for seizure recurrence over 1 year. Board-certified neurologists or epileptologists evaluated all EEG findings. We investigated the relationship between EEG findings and seizure recurrence. Among 187 patients with poststroke epilepsy (65 were women with a median age of 75 years) admitted to the lead hospital, 48 (25.7%) had interictal epileptiform discharges on EEG. During the follow-up period (median, 397 days; interquartile range, 337-450 days), interictal epileptiform discharges were positively correlated with seizure recurrence (hazard ratio, 3.82; 95% confidence interval, 2.09-6.97; P < 0.01). The correlation remained significant even after adjusting for age, sex, severity of stroke, type of stroke and generation of antiseizure medications. We detected periodic discharges in 39 patients (20.9%), and spiky/sharp periodic discharges were marginally associated with seizure recurrence (hazard ratio, 1.85; 95% confidence interval, 0.93-3.69; P = 0.08). Analysis of a validation cohort comprising 187 patients with poststroke epilepsy from seven other hospitals corroborated the association between interictal epileptiform discharges and seizure recurrence. We verified that interictal epileptiform discharges are a risk factor for seizure recurrence in patients with poststroke epilepsy. Routine EEG may facilitate the estimation of seizure recurrence risk and the development of therapeutic regimens for poststroke epilepsy.

Association Between IL-6 and Seizure Recurrence in Patients with the First Post-Ischemic Stroke Seizure

PURPOSE

To study the association between IL-6 level and seizure recurrence in patients with the first post-ischemic stroke seizure and assess its predictive value for seizure recurrence.

PATIENTS AND METHODS

A total of 2976 consecutive ischemic stroke patients were retrospectively enrolled. Among them, 209 (7.02%) patients with the first post-ischemic stroke seizure were included in this analysis. The IL-6 mRNA expression level was evaluated through quantitative real-time PCR (qRT-PCR) and the 2^-ΔΔCt method. Demographic data and clinical characteristics were collected. Univariate analysis was performed with independent-samples t-test, Mann-Whitney U-test, or chi-square test. Multivariate analysis was conducted using a backward stepwise logistic regression model for variables with P<0.10 in univariate analysis. The predictive value was assessed using a receiver operating characteristic (ROC) curve.

RESULTS

Among the patients included, 105 (50.24%) had recurrence of seizures, and 104 (49.76%) had no recurrence. Multivariate analysis demonstrated that the IL-6 mRNA expression level was independently correlated with seizure recurrence in patients with the first post-ischemic stroke seizure after adjusting for age, NIHSS scores, time of seizure, seizure type, lesion size, location of the offending lesion to different hemispheric lobes, cortical involvement, gender, electroencephalography (EEG) findings, and hemorrhagic transformation. When the IL-6 mRNA expression level was used to predict seizure recurrence, the area under the ROC curve (AUC) was 0.763 (SE=0.033, 95% CI=0.698-0.829). The diagnostic power was moderate.

CONCLUSION

IL-6 was independently correlated with seizure recurrence in patients with the first post-ischemic stroke seizure and might be a potential biomarker for prediction of seizure recurrence.