1. Department of Anesthesiology; Critical Care and Multidisciplinary Pain Center; Ziekenhuis Oost-Limburg; Genk/Lanaken Belgium
2. Pain Clinic; Department of Anesthesiology; University Medical Center Utrecht; Utrecht The Netherlands
3. Multidisciplinary Pain Center; Antwerp University Hospital; Edegem Belgium
4. Laboratory for Pain Research; University of Antwerp; Wilrijk Belgium
5. Department of Pain Management; Westfriesgasthuis; Hoorn The Netherlands
6. Department of Anesthesiology and Pain Management; Rijnstate Ziekenhuis; Arnhem The Netherlands
7. Department of Anesthesiology, Pain and Palliative Medicine; Radboud University Nijmegen Medical Center; Nijmegen The Netherlands
8. Department of Anesthesiology and Pain Management; University Medical Centre Maastricht; Maastricht The Netherlands
9. Department of Anesthesia and Critical Care; Massachusetts General Hospital; Boston Massachusetts U.S.A.
10. Department of Anesthesia; Harvard Medical School; Boston Massachusetts U.S.A.