Is There a Gender Difference in the Response to onabotulinumtoxinA in Chronic Migraine? Insights from a Real-Life European Multicenter Study on 2879 Patients - Ornello, Raffaele (University of L'Aquila. Department of Applied Clinical Sciences and Biotechnology) ; Ahmed, Fayyaz (Hull University Teaching Hospitals. Department of Neurosciences) ; Negro, Andrea (Sapienza University. Department of Clinical and Molecular Medicine) ; Miscio, Anna Maria (Fondazione IRCCS "Casa Sollievo della Sofferenza". Unit of Neurology) ; Santoro, Antonio (Fondazione IRCCS "Casa Sollievo della Sofferenza". Unit of Neurology) ; Alpuente, Alicia (Hospital Universitari Vall d'Hebron) ; Russo, Antonio (University of Campania "Luigi Vanvitelli". Department of Medical, Surgical, Neurological, Metabolic, and Aging Sciences) ; Silvestro, Marcello (University of Campania "Luigi Vanvitelli". Department of Medical, Surgical, Neurological, Metabolic, and Aging Sciences) ; Cevoli, Sabina (IRCCS Istituto delle scienze Neurologiche di Bologna) ; Brunelli, Nicoletta (Campus Bio-Medico University Hospital. Headache and Neurosonology Unit) ; Vernieri, Fabrizio (Campus Bio-Medico University Hospital. Headache and Neurosonology Unit) ; Grazzi, Licia (IRCCS Foundation "Carlo Besta" Neurological Institute. Neurology Department) ; Baraldi, Carlo (University of Modena and Reggio Emilia. Department of Biomedical, Metabolic and Neural Sciences) ; Guerzoni, Simona (University of Modena and Reggio Emilia. Department of Biomedical, Metabolic and Neural Sciences) ; Andreou, Anna P. (Guy's and St Thomas' NHS Foundation Trust. Headache Service) ; Lambru, Giorgio (Guy's and St Thomas' NHS Foundation Trust. Headache Service) ; Kamm, Katharina (Ludwig Maximilians University München. Department of Neurology) ; Ruscheweyh, Ruth (Ludwig Maximilians University München. Department of Neurology) ; Russo, Marco (Azienda USL-IRCCS di Reggio Emilia. Neuromotor and Rehabilitation Department) ; Torelli, Paola (University of Parma. Headache Center) ; Filatova, Elena (Sechenov First Moscow State Medical University (Sechenov University). Department of Neurology) ; Latysheva, Nina (Sechenov First Moscow State Medical University (Sechenov University). Department of Neurology) ; Gryglas-Dworak, Anna (Headache Center Wroclaw) ; Straburzyński, Marcin (Headache Clinic (Warsaw, Poland)) ; Butera, Calogera (IRCCS San Raffaele Scientific Institute. Neurophysiology Service) ; Colombo, Bruno (IRCCS San Raffaele Scientific Institute (Milà, Itàlia). Neurology Unit) ; Filippi, Massimo (IRCCS San Raffaele Scientific Institute. Neurorehabilitation Unit) ; Pozo-Rosich, Patricia (Hospital Universitari Vall d'Hebron) ; Martelletti, Paolo (Sapienza University. Department of Clinical and Molecular Medicine) ; Sacco, Simona (University of L'Aquila. Department of Applied Clinical Sciences and Biotechnology) ; Universitat Autònoma de Barcelona