The fundamental reason for comparing the ability of the Frontal Sedline TM Electroencephalogram (PSA EEG) to standard Global 12 Lead Electroencephalogram (EEG) for burst suppression detection is to determine if a less expensive, less invasive and possibly more convenient bifrontal EEG monitor can be effective for evaluation of anesthesia-induced intraoperative burst suppression therapy (IBST) for cerebral protection.

Inclusion Criteria:

1. Adult ASA class 1-3 male or female 18-90 years of age;
2. scheduled for elective craniotomy in the LLUMC University Hospital, for which the surgeon has requested intraoperative burst suppression therapy;
3. capable of understanding and signing informed consent;
4. willing to have dual EEG monitoring.

Exclusion Criteria:

1. Age under 18 years;
2. emergency or trauma situation requiring craniotomy;
3. surgical approach that prohibits placing the SEDLineTM array on the forehead;
4. known sensitivity to the adhesives on the SEDLineTM array;
5. lack of availability of standard EEG monitoring;
6. patients with seizure disorders and refusal of consent.

Adult patients scheduled for elective craniotomy or transphenoidal pituitary resection at LLUMC University Hospital in which the surgeon has requested intraoperative burst suppression therapy regardless of the inciting etiology will be eligible to participate in this study.