[1] Univ Pavia, Dept Neurol Sci, I-27100 Pavia, Italy
[2] IRCCS C Mondino Inst Neurol, Eye Movement & Vestibular Lab, Pavia, Italy
[3] UCADH, Headache Diag & Treatment Ctr, Pavia, Italy
[4] Casa di Cura Mater Domini, Castellanza, Italy
[5] Circolo Hosp Varese, Neurol Unit, Varese, Italy
[6] Univ Insubria, Varese, Italy
[7] Univ Roma La Sapienza, Dept Neurol & ORL, Rome, Italy