1. Department of Neurology, Schlosspark-Klinik, Berlin, Germany
2. Danish Headache Center and Department of Neurology, University of Copenhagen, Copenhagen, Denmark
3. Departments of Otolaryngology and Neurology, University of Pittsburgh, Pittsburgh, PA, USA
4. Department of Neurology and Monash University Department of Medicine, Alfred Hospital, Melbourne, Australia
5. Department of Clinical Neuroscience, Charing Cross Hospital, London, UK
6. Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins University School of Medicine, Baltimore, MD, USA
7. Department of Neurology, Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg
8. Department of Neurological Sciences University of Pavia, HSC and BCC National Neurological Institute IRCCS C. Mondino Foundation, Pavia, Lombardy, Italy
9. Department of Neurology, University of Münster, Münster, Germany
10. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA