1. Danish Headache Center, Rigshospitalet Glostrup University of Copenhagen Copenhagen Denmark
2. Department of Neurology Albert Einstein College of Medicine Bronx NY USA
3. Department of Neurology Georgetown University Hospital Washington DC USA
4. Department of Neurology Vrije Universiteit Brussel (VUB), Universitair Ziekenhuis Brussel (UZ Brussel) Brussels Belgium
5. Department of Biotechnological and Applied Clinical Sciences University of L'Aquila L'Aquila Italy
6. First Neurology Department, Aeginition Hospital, Medical School National and Kapodistrian University of Athens Athens Greece
7. H. Lundbeck A/S Copenhagen Denmark