1. Department of Neurosurgery, Thomas Jefferson University Hospital, Philadelphia, PA, USA;
2. Department of Neurosurgery, The Dartmouth Institute for Health Policy and Clinical Practice, Lebanon, NH, USA;
3. Department of Neurosurgery, Geisel School of Medicine at Dartmouth, Hanover, NH, USA;
4. Center for Neuro and Spine, Akron General Hospital-Clevel and Clinic, Akron, OH, USA;
5. Department of Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA;
6. Department of Community and Family Medicine, Dartmouth-Hitchcock Medical Center, Lebanon, NH, USA