1. Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
2. Headache Science & Neurorehabilitation Center, Istituto di Ricovero e Cura a Carattere Scientifico Mondino Foundation, Pavia, Italy
3. Department of Brain and Behavioral Sciences, University of Pavia, Pavia, Italy
4. Novartis Pharma AG, Basel, Switzerland
5. Department of Clinical Biochemistry, Bispebjerg Frederiksberg Hospital, Faculty of Health Sciences, University of Copenhagen, Copenhagen, Denmark