1 Department of Neurosurgery, Penn State Hershey Medical Center & Penn State College of Medicine, Hershey, Pennsylvania, USA.
2 Department of Neurosurgery, Penn State Hershey Medical Center & Penn State College of Medicine, Hershey, Pennsylvania, USA; Department of Radiology, Penn State Hershey Medical Center & Penn State College of Medicine, Hershey, Pennsylvania, USA; Department of Public Health Sciences, Penn State Hershey Medical Center & Penn State College of Medicine, Hershey, Pennsylvania, USA.