1. Department of Neurosurgery, University of Texas Health San Antonio, San Antonio, Texas, USA.
2. Department of Neurosurgery, Naval Medical Center San Diego, San Diego, California, USA.
3. Department of Neurosurgery, Clinical Neurosciences Center, University of Utah, Salt Lake City, Utah, USA.
4. Long School of Medicine, University of Texas Health San Antonio, San Antonio, Texas, USA.
5. Department of Neurosurgery, University of Virginia, Charlottesville, Virginia, USA.