1. Euromedica General Clinic, 54645 Thessaloniki, Greece
2. Headache Outpatient Clinic, Department of Neurology, Agios Andreas State General Hospital of Patras, 26335 Patras, Greece
3. Greek Society of Migraine and Headache Patients, 11743 Athens, Greece
4. 404 Military Hospital, 41222 Larissa, Greece
5. Department of Neurology, University Hospital of Larissa, University of Thessaly, 41110 Larissa, Greece
6. Independent Researcher, 24100 Kalamata, Greece
7. Headache Clinic, Mediterraneo Hospital, 16675 Athens, Greece