1. Division of Neurosurgery (ECB) and the Departments of Radiology (JDL, WWO), Psychology (JDL), and Neurology (WWO), The University of New Mexico School of Medicine, Albuquerque, New Mexico, The Division of Neurosurgery, Saint Louis University Medical Center, St. Louis, Missouri (RDB), and The New Mexico Regional Federal Medical Center, Albuquerque, New Mexico (JDL, WWO)