1. Headache Outpatient Clinic, Department of Neurology, Saint Andrew’s State General Hospital of Patras, Patras, Greece
2. Headache Clinic, Mediterraneo Hospital, Glyfada, Greece
3. Glyfada Headache Clinic, Glyfada, Greece
4. Department of Neurosciences, Biomedicine and Movement Sciences, University of Verona, Verona, Italy