1. Department of Neurosurgery, Pennsylvania State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
2. University of Michigan Medical School, Ann Arbor, MI, USA
3. Center for Applied Studies in Health Economics, Pennsylvania State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
4. Department of Anesthesia and Perioperative Services, Pennsylvania State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA
5. Department of Radiology, Pennsylvania State University College of Medicine, Penn State Milton S. Hershey Medical Center, Hershey, PA, USA