[1] Fdn G Giglio Cefalu, Anesthesiol & Pain Dept, Palermo, Italy
[2] Guys & St Thomas NHS Fdn Trust, Walton Ctr Neurol & Neurosurg, Liverpool, England
[3] Univ Pavia, Dept Clin Surg Diagnost & Pediat Sci, I-27100 Pavia, Italy
[4] Fdn IRCCS Policlin San Matteo, Pain Unit, Pavia, Italy
[5] Univ Wisconsin, Dept Anesthesiol, Div Chron Pain, Sch Med & Publ Hlth, Madison, WI USA
[6] Fac Med, Dept Stereotact & Funct Neurosurg, Cologne, Germany
[7] Univ Hosp, Cologne, Germany
[8] AO Osped Colli, Monaldi Hosp, Dept Pain Management, Naples, Italy
[9] Carolinas Pain Inst, Winston Salem, NC USA
[10] ElectroCore, Rockaway, NJ USA
[11] Natl Spine & Pain Ctr, Rockville, MD USA