1. Department of Neurology, Mayo Clinic, Rochester, MN, USA
2. Department of Neurology, Centre Hospitalier Emile Mayrisch, Esch-sur-Alzette, Luxembourg
3. Private Practice of Neurology and Department of Neurology, Charité, Berlin, Germany
4. Department of Neurology, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
5. Department of Neurology, Seoul National University College of Medicine, Seoul National University Bundang Hospital, Seoul, Korea
6. Department of Otorhinolaryngology, Clínica Universidad de Navarra, Madrid, Spain
7. Institute of Clinical Neurosciences, Royal Prince Alfred Hospital, Central Clinical School, University of Sydney, Sydney, Australia
8. Department of Otolaryngology-Head and Neck Surgery, The Johns Hopkins University School of Medicine, Baltimore, MD, USA