Early electroencephalography in acute ischemic stroke: Prediction of a malignant course?

Objective In patients with large middle cerebral artery (MCA) infarction space occupying brain edema may lead to a malignant course with up to 80% mortality under conservative treatment. As interventional treatment strategies must be started before the deterioration occurs predictors of a malignant course are necessary. Patients and methods This study reports on the results of early electroencephalography (EEG) within 24 h after onset of stroke in 25 patients suffering a large MCA infarct (12 patients with a malignant and 13 with a non-malignant course). EEG analysis was performed according well-established indicators for focal as well as global changes. Results Our findings indicate that the absence of delta activity and the presence of theta and fast beta frequencies within the focus predict a benign course (p < 0.05), whereas diffuse generalized slowing and slow delta activity in the ischemic hemisphere may point to a malignant course. Conclusion This study shows that in patients suffering from large MCA infarction early EEG delivers useful information to select those patients who develop malignant edema.