1. Department of Neurological Sciences, IRCCS C. Mondino, University of Pavia
2. University Centre for Adaptive Disorders and Headache (UCADH), Varese
3. University Centre for Adaptive Disorders and Headache (UCADH), Pavia, Italy
4. Department of Neurology, St. Olavs Hospital, Norwegian University of Technology and Science, Trondheim, Norway
5. Department of Neurology and Otorhinolaringology, La Sapienza University, Rome, Italy