1. Institute for Medical Informatics, Biometry and Epidemiology, University Duisburg-Essen, Essen, Germany
2. Headache Science Center, C. Mondino Foundation (IRCCS), Pavia, Italy
3. Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
4. Department of Neurology, Mayo Clinic, Phoenix, AZ, USA
5. Jefferson Headache Center, Thomas Jefferson University, Philadelphia, PA, USA
6. Montefiore Headache Center, Department of Neurology and Department of Epidemiology and Population Health, Albert Einstein College of Medicine, Bronx, NY, USA
7. Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Glostrup, Denmark
8. Dept of Clinical Neurosciences, University of Calgary, Calgary, Alberta, Canada
9. Hotchkiss Brain Institute, Calgary, Canada
10. Department of Neurology, Leiden University Medical Center, Leiden, the Netherlands
11. National Institute for Health Research-Wellcome Trust King’s Clinical Research Facility, King’s College London, UK
12. Headache Unit, Neurology Department, Vall d’Hebron University Hospital & Headache Research Group, Vall d’Hebron Research Institute, Universitat Autònoma de Barcelona, Barcelona, Spain
13. Neurological Institute, Taipei Veterans General Hospital, Taipei, Taiwan
14. Brain Research Center and School of Medicine, National Yang-Ming University, Taipei, Taiwan
15. Harvard Medical School, Boston, MA, USA
16. Leiden University Medical Center, Leiden, the Netherlands