1. Department of Neurological Surgery, University of Washington, Harborview Medical Center;
2. Departments of Biostatistics,
3. Rehabilitation Medicine, and
4. Hospital Nacional Profesor Alejandro Posadas, Buenos Aire;
5. Hospital de Emergencias Dr. Clemente Alvarez, Rosario;
6. Hospital Emergencia, Hospital Privado de Rosario, Rosario, Argentina; and
7. Hospital Erasmo Meoz, Cucuta, Colombia
8. Orthopaedics and Sports Medicine, University of Washington, Seattle, Washington;