1. Department of Physical Medicine and Rehabilitation, Hospital Professor Doutor Fernando Fonseca , 2720-276 Amadora, Portugal
2. Washington and Lee University , Lexington, VA 24450, United States
3. Department of Anesthesiology, Centro Hospitalar Universitário de Lisboa Norte , 1649-028 Lisboa, Portugal
4. Division of Pain Medicine, Department of Anesthesiology, Reanimation, and Pain Medicine, Hospital Clínic de Barcelona , Barcelona, 08036 Catalonia, Spain
5. Department of Radiology, Mayo Clinic , Jacksonville, FL 32224, United States
6. Department of Pain Medicine, Mayo Clinic , Jacksonville, FL 32224, United States