Late Seizures after Stroke in Clinical Practice: The Prevalence of Non-convulsive Seizures

Clinical and imaging features of nonmotor onset seizure in poststroke epilepsy

OBJECTIVE

Motivated by the challenges raised by diagnosing poststroke epilepsy (PSE), especially in nonmotor onset seizure (non-MOS), we aimed to investigate features of non-MOS, including seizure sequences, patient characteristics, and electrophysiological and imaging findings in PSE.

METHODS

This observational cohort study enrolled patients with PSE whose seizure onset was witnessed. According to the International League Against Epilepsy 2017 seizure classification, we classified seizure onset symptoms into the non-MOS and MOS groups. We compared different clinical characteristics between the two groups.

RESULTS

Between 2011 and 2018, we enrolled 225 patients with PSE (median age, 75 years), consisting of 97 (43%) with non-MOS and 128 (57%) with MOS. Overall, 65 (67%) of the patients without MOS had no subsequent convulsions. Multivariable logistic regression analysis showed significant associations of non-MOS with absence of poststroke hemiparesis (adjusted odds ratio [OR], 1.88; 95% confidence interval [CI], 1.03-3.42), frontal stroke lobe lesions (OR, 2.11; 95% CI, 1.14-3.91), and putaminal stroke lesions (OR, 2.51; 95% CI, 1.22-5.18) as negative indicators. Postictal single-photon emission-computed tomography detected prolonged hyperperfusion in the temporal lobe more frequently in the non-MOS than in the MOS group (48% vs. 31%; p = 0.02). The detection rate was higher than spikes/sharp waves in scalp electroencephalogram both in the non-MOS group (72% vs. 33%; p < 0.001) and the MOS group (68% vs. 29%; p < 0.001).

SIGNIFICANCE

This study provides clinical features of non-MOS in patients with PSE. Compared with the patients with MOS, the ones with non-MOS showed less likely subsequent convulsive seizures, highlighting the clinical challenges. Postictal perfusion imaging and negative indicators of non-MOS type may help diagnose and stratify PSE.

Associated Factors and Prognostic Implications of Non-convulsive Status Epilepticus in Ischemic Stroke Patients With Impaired Consciousness

Background and Purpose: Non-convulsive status epilepticus (NCSE) is common in patients with disorders of consciousness and can cause secondary brain injury. Our study aimed to explore the determinants and prognostic significance of NCSE in stroke patients with impaired consciousness.

Method: Consecutive ischemic stroke patients with impaired consciousness who were admitted to a neuro intensive care unit were enrolled for this study. Univariate and multivariable logistic regression were used to identify factors associated with NCSE and their correlation with prognosis.

Results: Among the 80 patients studied, 20 (25%) died during hospitalization, and 51 (63.75%) had unfavorable outcomes at the 3-month follow-up. A total of 31 patients (38.75%) developed NCSE during 24-h electroencephalogram (EEG) monitoring. Logistic regression revealed that NCSE was significantly associated with an increased risk of death during hospital stay and adverse outcomes at the 3-month follow-up. Patients with stroke involving the cerebral cortex or those who had a severely depressed level of consciousness were more prone to epileptogenesis after stroke.

Conclusion: Our results suggest that NCSE is a common complication of ischemic stroke, and is associated with both in-hospital mortality and dependency at the 3-month follow-up. Long-term video EEG monitoring of stroke patients is, therefore required, especially for those with severe consciousness disorders (stupor or coma) or cortical injury.

Poststroke seizure: optimising its management

Seizure after stroke or poststroke seizure (PSS) is a common and very important complication of stroke. It can be divided into early seizure and late seizure, depending on seizure onset time after the stroke. It has been reported that ischaemic and haemorrhagic stroke accounts for about 11% of all adult epilepsy cases and 45% of epilepsy cases over 60 years of age. However, there are no reliable guidelines in clinical practice regarding most of the fundamental issues of PSS management. In recent years there has been an increased interest in the study of PSS which may give clinical practitioners a better picture of how to optimise PSS management. Studies have indicated two peaks in PSS occurrence—the first day and 6–12 months after a stroke. Haemorrhagic stroke, cortical involvement, severity of initial neurological deficit, younger patients (<65 years of age), family history of seizures and certain genetic factors carry a higher risk of PSS. The use of continuous electroencephalogram has demonstrated significant benefits in capturing interictal or ictal abnormalities, especially in cases of non-convulsive seizures and non-convulsive status epilepticus. Current available data indicated that there was no significant difference in antiepileptic efficacy among most of the antiepileptic drugs (AEDs) in PSS. Levetiracetam and lamotrigine are the most studied newer generation AEDs and have the best drug tolerance. The purpose of this review is to summarise the recent advances in PSS research and focus on the most important practice issues of PSS management.

Outcome and predictive factors in post-stroke seizures: A retrospective case-control study

PURPOSE

To evaluate clinical, radiographic, and electrophysiological features in the development and prognosis of ischemic post-stroke seizures (PSS).

METHOD

A retrospective study of 1119 patient records was performed between January 2006 and December 2016. After selection, 42 patients with seizures due to ischemic stroke were matched to a control group of 60 patients where seizures were absent. Stroke size and severity were analyzed using ASPECTS and NIHSS, respectively. Hemorrhagic transformation graded by ECASS III classification. Outcomes were assessed using the modified Rankin Scale. Fisher's exact test assessed categorical variables, and Mann-Whitney tested continuous variables.

RESULTS

Forty-two patients experienced PSS (22 females; median age 72.5 years) and were matched with 60 control subjects that had ischemic stroke without seizures. Focal seizures were present in 42.9% (18/42), and focal to bilateral convulsions in 57.1% (24/42). Stroke localization and severity did not differ (p = 0.6 and 0.21, respectively). Stroke size in anterior circulation was larger in PSS patients (median ASPECTS 6 vs 8 [p = 0.01]). Posterior circulation stroke size was similar in both groups. The presence of hemorrhage was the primary risk factor for PSS (61.9%) compared to controls (36.7%), p = 0.01. The presence of laminar necrosis (LN) (47.6% vs 21.6%, p = 0.005) and hemosiderin deposition (38.1% vs 18.3%, p = 0.02) were most predictive. PSS patients demonstrated worse outcomes than the controls (median mRS 3 vs 2, [p=<0.001]) with a median follow up of 14.8 and 20.7 months, respectively.

CONCLUSIONS

The size of anterior infarction, presence of blood products within the infarct bed, and especially LN predicted PSS.