Current Clinical Evidence Supporting the Use of Continuous EEG Monitoring for Delayed Cerebral Ischemia Detection

The EEG signal is the closest available measure of brain function and is exquisitely sensitive to ischemia. Data from animal models and from intraoperative monitoring suggest that continuous EEG monitoring is able disclose changes suggestive of impeding ischemia before infarction occurs. Several small studies in patients with aneurysmal subarachnoid hemorrhage now provide preliminary evidence that it can also be successfully applied to detection of delayed cerebral ischemia with a good sensitivity. These studies relied on quantitative analysis, underscoring the necessity to introduce such methods in clinical practice. Further improvements in quantitative EEG analysis, integration in a multimodality monitoring framework, and prospective validation studies are now required to confirm the utility of EEG monitoring for delayed cerebral ischemia detection.