1. Department of Neurosurgery, Barrow Neurological Institute, St. Joseph's Hospital and Medical Center, Phoenix, Arizona, USA;
2. Department of Neurosurgery, Drexel University College of Medicine, Drexel University, Philadelphia, Pennsylvania, USA;
3. Department of Neurosurgery, Jefferson University, Philadelphia, Pennsylvania, USA;
4. Department of Neurosurgery, University of California, Los Angeles, Los Angeles, California, USA;
5. Department of Neurosurgery, New York University, New York, New York, USA;
6. Department of Neurosurgery, Washington University School of Medicine, St Louis, Missouri, USA;
7. Department of Neurosurgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania, USA;
8. Department of Neurosurgery, Stanford University, Palo Alto, California, USA;
9. Department of Neurosurgery, University of Southern California, Los Angeles, California, USA;
10. Department of Neurosurgery, University of Utah, Salt Lake City, Utah, USA;
11. Division of Endocrinology, Metabolism and Lipid Research, Washington University School of Medicine, St Louis, Missouri, USA;
12. Department of Neurosurgery, Cleveland Clinic Foundation, Cleveland, Ohio, USA;
13. Department of Neurosurgery, University of Missouri, Columbia, Missouri, USA