1. Headache Research Unit, Department of Neurology, CHR Citadelle, Liège University, Belgium
2. Danish Headache Centre, Department of Neurology, Glostrup Hospital, University of Copenhagen, Denmark
3. Département d’Evaluation et Traitement de la Douleur, Pôle Neurosciences Cliniques CHU de Nice, France
4. Department of Neurology, Hospital Clinico Universitario, Universidad Católica de Valencia, Spain
5. Department of Neurology, University Duisburg-Essen, Germany
6. Autonomic Technologies, Inc., CA, USA
7. Department of Systems Neuroscience, Universitäts-Krankenhaus Eppendorf, Germany