1. Danish Headache Center, Department of Neurology, Copenhagen University Hospital – Rigshospitalet Glostrup, Glostrup, Denmark
2. Department of Neurology, Copenhagen University Hospital – Herlev and Gentofte, Herlev, Denmark
3. Department of Clinical Medicine, Faculty of Medical and Health Sciences, University of Copenhagen, Copenhagen, Denmark
4. Research Unit for Neurology, Odense University Hospital, Odense, Denmark; University of Southern Denmark, Odense, Denmark
5. Department of Public Health, Section of Environmental Health, University of Copenhagen, Copenhagen, Denmark
6. Danish Research Centre for Magnetic Resonance, Copenhagen University Hospital – Amager and Hvidovre, Hvidovre, Denmark
7. Department of Radiology, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital – Amager and Hvidovre, Hvidovre, Denmark
8. The Danish Twin Registry, Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark
9. Odense Patient data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark
10. Department of Neurology, Copenhagen University Hospital – Bispebjerg and Frederiksberg, Copenhagen, Denmark
11. Department of Applied Mathematics and Computer Science, Technical University of Denmark, Kgs. Lyngby, Denmark