1. Department of Neurology, Odense University Hospital, Denmark, Odense, Denmark
2. Department of Clinical Research, Faculty of Health Sciences, University of Southern Denmark, Odense, Denmark
3. Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Denmark
4. Danish Research Centre for Magnetic Resonance, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark
5. Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark
6. Department of Radiology, Centre for Functional and Diagnostic Imaging and Research, Copenhagen University Hospital Hvidovre, Denmark
7. The Danish Twin Registry, Epidemiology, Biostatistics and Biodemography, Institute of Public Health, University of Southern Denmark, Odense, Denmark
8. Odense Patient data Explorative Network (OPEN), Odense University Hospital, Odense, Denmark
9. Department of Neurology, Copenhagen University Hospital Bispebjerg, Denmark