[1] Univ Texas, MD Anderson Canc Ctr, Dept Neurosurg, Houston, TX 77030 USA
[2] Beth Israel Deaconess Med Ctr, Dept Pain Med & Palliat Care, New York, NY 10003 USA
[3] Univ Sydney, Pain Management Res Inst, Sydney, NSW 2006, Australia
[4] Royal N Shore Hosp, Sydney, NSW, Australia
[5] Hop Zone Morges, Anesthesia & Pain Management Serv, Morges, Switzerland
[6] W Virginia Univ, Sch Med, Ctr Pain Relief, Charleston, WV 25304 USA
[7] Swedish Med Ctr, Swedish Pain Consultat Serv, Seattle, WA USA
[8] Wake Forest Univ, Dept Anesthesiol, Winston Salem, NC 27109 USA
[9] Univ Iowa Hosp & Clin, Dept Neurosurg, Iowa City, IA 52242 USA
[10] Medtronic Inc, Minneapolis, MN USA
[11] Pacific Pain Treatment Ctr, San Francisco, CA USA
[12] Northwestern Univ, Chicago, IL 60611 USA
[13] Univ Calif San Francisco, Pain Management Ctr, San Francisco, CA 94143 USA
[14] Univ Vermont, Coll Med, Burlington, VT USA
[15] Piedmont Anesthesia & Pain Consultants PA, Winston Salem, NC USA
[16] Johns Hopkins Univ, Sch Med, Baltimore, MD USA
[17] Valley Pain Treatment Ctr, Scottsdale, AZ USA
[18] Alabama Pain Ctr, Huntsville, AL USA