1. Department of Palliative Medicine; University Hospital of Bonn; Bonn Germany
2. Pain Research and Nuffield Department of Clinical Neurosciences (Nuffield Division of Anaesthetics); University of Oxford; Oxford UK
3. Pain Clinic; Universitätsmedizin Göttingen; Göttingen Germany
4. Department of Psychosomatic Medicine and Psychotherapy; Technische Universität München; München Germany