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. Monash University Department of Neuroscience, 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. Neurology and Stroke Unit, ASST Sette Laghi, Ospedale di Circolo, Varese, Italy
9. University of Insubria, Varese, Italy
10. Department of Neurology, Krankenhaus Lindenbrunn, Coppenbrügge, Germany
11. Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA