Seizures, electroencephalographic abnormalities, and outcome of ischemic stroke patients

Abstract

SummaryObjectiveSeizures and electroencephalographic (EEG) abnormalities have been associated with unfavorable stroke functional outcome. However, this association may depend on clinical and imaging stroke severity. We set out to analyze whether epileptic seizures and early EEG abnormalities are predictors of stroke outcome after adjustment for age and clinical/imaging infarct severity.MethodsA prospective study was made on consecutive and previously independent acute stroke patients with a National Institutes of Health Stroke Scale (NIHSS) score ≥ 4 on admission and an acute anterior circulation ischemic lesion on brain imaging. All patients underwent standardized clinical and diagnostic assessment during admission and after discharge, and were followed for 12 months. Video‐EEG (<60 min) was performed in the first 72 h. The Alberta Stroke Program Early CT Score quantified middle cerebral artery infarct size. The outcomes in this study were an unfavorable functional outcome (modified Rankin Scale [mRS] ≥ 3) and death (mRS = 6) at discharge and 12 months after stroke.ResultsUnfavorable outcome at discharge was independently associated with NIHSS score (p = 0.001), EEG background activity slowing (p < 0.001), and asymmetry (p < 0.001). Unfavorable outcome 1 year after stroke was independently associated with age (p = 0.001), NIHSS score (p < 0.001), remote symptomatic seizures (p = 0.046), EEG background activity slowing (p < 0.001), and asymmetry (p < 0.001). Death in the first year after stroke was independently associated with age (p = 0.028), NIHSS score (p = 0.001), acute symptomatic seizures (p = 0.015), and EEG suppression (p = 0.019).SignificanceAcute symptomatic seizures were independent predictors of vital outcome and remote symptomatic seizures of functional outcome in the first year after stroke. Therefore, their recognition and prevention strategies may be clinically relevant. Early EEG abnormalities were independent predictors and comparable to age and early clinical/imaging infarct severity in stroke functional outcome discrimination, reflecting the concept that EEG is a sensitive and robust method in the functional assessment of the brain.

Early EEG predicts poststroke epilepsy

“…These data add a neurophysiological risk factor to poststroke seizures, reflecting not only their association with large and disabling ischemic strokes but also the importance of EEG for brain functional assessment. In fact, recently, first EEG asymmetry was also reported as an independent predictor of unfavorable stroke functional outcome, even when adjusted for age and clinical and imaging stroke severity …”

Quantitative EEG and functional outcome following acute ischemic stroke

“…Using DeLong tests, the outcome prediction model including the qEEG index with highest cvAUCs was compared with the model including exclusively known stroke outcome predictors, as well as with models using known predictors and visual EEG analysis variables, namely background activity asymmetry. EEG background asymmetry was chosen in accordance to a previous report where it was shown that this was the variable more strongly associated with anterior circulation ischaemic stroke outcome (Bentes et al, 2017c). Cut-off values were calculated for various sensitivities and specificities.…”

An interview with Carla Bentes, 2018 Epilepsia Open Prize Winner for Clinical Research

“…The global aim of this thesis was to use the clinical model of acute ischemic cerebrovascular disease to study the value of EEG in the differential diagnosis of transient neurological symptoms, in the diagnosis and prediction of poststroke seizures and epilepsy, as well as to analyze if electroencephalographic abnormalities and/or epileptic seizures are independent predictors of an anterior circulation ischemic stroke outcome, as described in this article published in Epilepsia Open . Furthermore, because the gold standard of acute stroke care (namely intravenous alteplase treatment) is associated with a reduction of mortality and incapacity of treated patients with possible consequences in poststroke seizure frequency, but a proconvulsive and an epileptogenic effect of alteplase has also been described, we aim to test the hypothesis that ischemic stroke patients treated with intravenous alteplase have a different frequency of epileptic (clinic and/or electroencephalographic) manifestations compared to nontreated patients .…”