We hypothesize that the EEGo monitor will be able to more accurately indicate if the brain is at risk of ischemia and better able to direct therapy to relieve the ischemic episode as compared to the BIS monitor. The EEGo will be superior because the raw signal is processed using phase delay analysis, with each patient's raw EEG analyzed instead of a proprietary but generic signal processing approach on a linear scale as with the BIS monitor. Phase delay analysis is a standard approach to display nonlinear signals. A highly reproducible signal transition occurs with differing depths of anesthesia. The ability to process the EEG and display phase delay plots in 50 msec is what makes the EEGo monitor attractive to acutely assess changes in the EEG which can manifest with cerebral ischemia. We also hypothesize that the FORE-SIGHT cerebral oximeter will be an effective monitor for detecting cerebral ischemia during CEA. Accurate assessment of changes in the EEG and cerebral tissue oxygen saturation with carotid cross-clamping will allow better anesthesia management of patients undergoing CEA.