1. Pain Management Unit Hospital Universitario Quirónsalud MadridHospital Quirónsalud San José MadridSpain
2. Hospital Universitario Quirónsalud Madrid Madrid Spain
3. Spine and Nerve Center of the Virginias Charleston West VirginiaU.S.A.
4. Division of Pain Medicine Department of Anesthesiology and Perioperative Medicine Mayo Clinic Rochester Minnesota U.S.A.
5. Instituto Aliaga Clínica Teknon BarcelonaSpain
6. Pain Management Department Hospital Universitario Quirónsalud Madrid Madrid Spain
7. National Spine and Pain Centers Rockville MD U.S.A.
8. Psychology Department Illinois Wesleyan University Bloomington Illinois U.S.A.