1. Department of Neuroscience; Norwegian University of Science and Technology; Trondheim Norway
2. Norwegian Advisory Unit on Headaches; St. Olav’s University Hospital; Trondheim Norway
3. Department of Neurology; Canisius Wilhelmina Ziekenhuis; Nijmegen Netherlands
4. (Deceased) Department of Psychology; University of Hawaii at Manoa; Manoa USA
5. Department of Medicine; Duke University Medical Center; Durham NC USA
6. Center for Health Services Research in Primary Care; Durham Veterans Affairs Medical Center; Durham NC USA