1. Department of Neurosurgery (FM, AB, HS, MO, MM, MP, ZAS), University of Oklahoma Health Sciences Center; Stephenson School of Biomedical Engineering (GH), University of Oklahoma, Norman; Department of Anesthesiology (KAW), Perioperative and Pain Medicine, Stanford School of Medicine, Palo Alto, CA; University of Texas Southwestern Medical Center (MVH, DD, YD), Dallas; and Department of Biostatistics and Epidemiology (YDZ), Hudson College of Public Health, University of Oklahoma Health Sciences Center.