1. Danish Headache Center, Department of Neurology, Rigshospitalet Glostrup, Faculty of Health and Medical Sciences, University of Copenhagen, Copenhagen, Denmark
2. BIDMC Comprehensive Headache Center, Department of Anesthesia, Critical Care and Pain Medicine, Harvard Medical School, Beth Israel Deaconess Medical Center, Boston, MA, USA
3. Montefiore Headache Center, Department of Neurology, Albert Einstein College of Medicine, New York, NY, USA
4. Department of Otolaryngology-Head and Neck Surgery, Otology, Neurotology, and Skull Base Surgery, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA
5. BIDMC Comprehensive Headache Center, Department of Anesthesia, Critical Care and Pain Medicine, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA