[1] Univ Texas, MD Anderson Canc Ctr, Dept Neurosurg, Houston, TX 77030 USA
[2] Med Coll Penn & Hahnemann Univ, Dept Neurol, Philadelphia, PA 19102 USA
[3] Oregon Hlth Sci Univ, Dept Neurol Surg, Portland, OR 97201 USA
[4] Hop Zone Morges, Anaesthesia & Pain Management Serv, Morges, Switzerland
[5] Trinity Pain Med Assoc PA, Ft Worth, TX USA
[6] Ctr Pain Relief, Charleston, WV USA
[7] Swedish Hosp, Dept Anesthesia, Seattle, WA USA
[8] Univ Penn Hlth Syst, Pain Med Ctr, Philadelphia, PA USA
[9] Texas Tech Univ, Hlth Sci Ctr, Dept Anesthesiol, Lubbock, TX 79430 USA
[10] AZ St Lucas, Ghent, Belgium
[11] Mt Sinai Med Ctr, Dept Neurosurg, New York, NY 10029 USA
[12] Beth Israel Med Ctr, Dept Pain Med & Palliat Care, New York, NY 10003 USA
[13] Wake Forest Univ, Baptist Med Ctr, Pain Control Ctr, Winston Salem, NC 27109 USA
[14] Ctr Pain Relief, Clarksburg, WV USA
[15] Alabama Pain Ctr, Huntsville, AL USA
[16] Univ Calif San Diego, Dept Anesthesiol, San Diego, CA 92103 USA