1. Fabio Frediani, Licia Grazzi, Boris Maurizio Zappacosta, Gennaro Bussone, Centro Cefalee, Istituto Neurologico “C. Besta”, via Celoria 11, 20133 Milano, Italy; Annalisa Zanotti, Federico Mailland, Development and Clinical Research Department, Poli Industria Chimica S.P.A. P.zza Agrippa 1, 20141 Milano, Italy;