Early EEG predicts poststroke epilepsy

Abstract

SummaryObjectiveElectroencephalography (EEG) can identify biomarkers of epileptogenesis and ictogenesis. However, few studies have used EEG in the prediction of poststroke seizures. Our primary aim was to evaluate whether early EEG abnormalities can predict poststroke epilepsy.MethodsA prospective study of consecutive acute anterior circulation ischemic stroke patients, without previous epileptic seizures, who were admitted to a stroke unit over 24 months and followed for 1 year. All patients underwent standardized clinical and diagnostic assessment during the hospital stay and after discharge. Video‐EEG was performed in the first 72 h (first EEG), daily for the first 7 days, in case of neurological deterioration, at discharge, and at 12 months after stroke. The occurrence of epileptic seizures in the first year after stroke (primary outcome) was evaluated clinically and neurophysiologically during the hospital stay and at 12 months. A telephone interview was also performed at 6 months. The primary outcome was the occurrence of at least one unprovoked seizure (poststroke epilepsy). Secondary outcomes were the occurrence of at least one acute symptomatic seizure and (interictal and/or ictal) epileptiform activity on at least one EEG during the hospital stay for acute stroke. The first EEG variables were defined using international criteria/terminology. Bivariate and multivariate analyses with adjustment for age, admission National Institutes of Health Stroke Scale (NIHSS) score, and Alberta Stroke Program Early CT Score (ASPECTS) were performed.ResultsA total of 151 patients were included; 38 patients (25.2%) had an acute symptomatic seizure and 23 (16%) had an unprovoked seizure.The first EEG background activity asymmetry and first EEG with interictal epileptiform activity were independent predictors of poststroke epilepsy during the first year after stroke (P = 0.043 and P = 0.043, respectively). No EEG abnormality independently predicted acute symptomatic seizures. However, the presence of periodic discharges on the first EEG was an independent predictor of epileptiform activity (p = 0.009) during the hospital stay.SignificanceAn early poststroke EEG can predict epilepsy in the first year after stroke, independently from clinical and imaging‐based infarct severity.

Stroke‐related epilepsy

“…Electroencephalography adds value to early diagnosis, outcome prediction, patient selection for treatment, clinical management and seizure detection in acute stroke . It can also be very helpful in the early evaluation of poorly defined post‐stroke focal neurologic symptoms and seizure mimics .…”

“…The most frequent EEG findings in acute stroke are focal slowing corresponding to side of infarct and diffuse slowing, both of which are associated with low risk for seizures . Focal spikes, sharp waves and periodic patterns including lateralized periodic discharges are associated with increased risk of seizures (STRE) .…”

“…Normal EEG was seen in 54% of the stroke patients without seizures, compared with only 8.5% of those with seizures. In a prospective study of 151 patients with stroke, first EEG background asymmetry and interictal epileptiform discharges were shown to predict STRE in the first year after stroke independent of clinical and image‐based infarct severity . Short‐term video EEG monitoring is also crucial in distinguishing epileptic seizures from seizure mimickers such as delirium and limb‐shaking transient ischaemic attacks, which are typically without EEG correlate.…”

FV18 Towards epileptogenesis staging with deep neural networks

“…Andrade et al investigated the role of sleep-wake disturbance in EPG and found that there is a decrease of the dominant frequency and the duration of sleep spindles in a traumatic brain injury epilepsy model with generalized seizures [9]. Bentes et al found that in stroke patients, the asymmetry in the background activity with the occurrence of IEDs are independent indicators of post-stroke epilepsy in the first year after stroke [10]. Sheybani et al found that in a mouse model of epilepsy with kainate injection, the spatial propagation of a subgroup of spikes across the brain can be a reliable indicator of EPG as well as epilepsy in the chronic phase [30].…”

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 .…”