3 Neuroscience Section, Department of Applied Clinical Sciences and Biotechnology, University of L'Aquila, Via Vetoio 1, Coppito, 67100, L'Aquila, Italy.
4 Department of Health Promotion, Mother and Child Care, Internal Medicine and Medical Specialties (PROMISE), University of Palermo, Piazza delle Cliniche 2, 90127, Palermo, Italy.
5 Department of Biomedicine, Neurosciences and Diagnostic (Bi.N.D.), University of Palermo, Via del Vespro 129, 90127, Palermo, Italy.
6 Department of Systems Medicine, University of Rome "Tor Vergata"; Neurology Unit, "Tor Vergata" Hospital, Viale Oxford, 81, 00133, Rome, Italy.
7 Department of Experimental Biomedicine and Clinical Neurosciences, University of Palermo, Via del Vespro, 129, 90127, Palermo, Italy.
8 Pain Medicine Unit, Santa Maria Maddalena Hospital, Occhiobello, Italy.
9 Regional Headache Referral Center, Sant'Andrea Hospital, Via di Grottarossa 1039, 00189, Rome, Italy.
10 Department of Medical, Surgical and Experimental Sciences, University of Sassari, Piazza Università, 21, 07100, Sassari, Italy.
11 Department of Neurology, University Hospital Ghent, Corneel Heymanslaan 10, 9000, Ghent, Belgium.
13 Department of Neurology, Conegliano Hospital, Via Brigata Bisagno, 2, 31015, Conegliano, Italy.
14 Department of Medico-Surgical Sciences and Biotechnologies, "Sapienza" University of Rome, Polo Pontino, Viale XXIV Maggio 7, 04100, Latina, Italy.
15 Department of Internal Medicine, Division of Pharmacology, Erasmus MC University Medical Centre Rotterdam, Wytemaweg 80, 3015, CN, Rotterdam, The Netherlands.
16 Department of Neurology, AZ Sint-Jan Brugge, Ruddershove 10, 8000, Brugge, Belgium.
17 Headache Research, Wolfson CARD, Institute of Psychiatry, Psychology & Neuroscience, King's College London, 20 Newcomen St, London, SE1 1YR, UK.
18 Headache Centre, Guy's and St Thomas NHS Trust, London, UK.
19 Department of Clinical and Molecular Medicine, Sapienza University of Rome, Via di Grottarossa 1039, 00189, Rome, Italy.