1. Division of Neurological Pain Research and Therapy; Department of Neurology; University Hospital of Schleswig-Holstein; Kiel Germany
2. Department of Anesthesiology and Critical Care Medicine; Philipps-University; Marburg Germany
3. Institute for Pain Medicine; Wiesbaden Germany
4. Health Center; Mainz Germany
5. Department of Palliative Medicine; Medical Faculty RWTH Aachen University; Aachen Germany
6. Department of Trauma, Hand and Foot Surgery; St. Martinus Hospital; Langenfeld Germany
7. Department of Neurology; Technische Universität; Munich Germany