Alessandro Tessitore1, Antonio Russo2. 1. Headache Center, Department of Advanced Medical and Surgery Sciences, University of Campania "Luigi Vanvitelli", Napoli 80138, Italy. Electronic address: alessandro.tessitore@unicampania.it. 2. Headache Center, Department of Advanced Medical and Surgery Sciences, University of Campania "Luigi Vanvitelli", Napoli 80138, Italy.