1. Danish Headache Center, Department of Neurology, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Nordre Ringvej 67, 2600 Glostrup, Denmark
2. Department of Diagnostics, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Nordre Ringvej 57, 2600 Glostrup, Denmark
3. Department of Neurosurgery, Rigshospitalet, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 9, 2100 Copenhagen, Denmark