1. Multidisciplinary Pain Clinic, Uppsala University Hospital, Uppsala, Sweden; Department of Surgical Sciences, Uppsala University, Uppsala, Sweden
2. Departement für Interventionelle Schmerzmedizin, Krankenhaus Neuwerk “Maria von den Aposteln” Muskulo-Skeletales Zentrum Mönchengladbach, Germany
3. Department of Anesthesiology and Pain Management, Diakonessenhuis Utrecht, Utrecht, the Netherlands
4. Ainsworth Institute of Pain Management, New York, New York
5. The Spine and Nerve Center of the Virginias, Charleston, West Virginia, USA