[1] Univ Med Ctr Maastricht, Dept Anesthesiol & Pain Management, Maastricht, Netherlands
[2] Radboud Univ Nijmegen, Med Ctr, Dept Pain Management & Palliat Care Med, NL-6525 ED Nijmegen, Netherlands
[3] Johns Hopkins Sch Med, Dept Anesthesiol & Crit Care Med, Baltimore, MD USA
[4] Walter Reed Army Med Ctr, Washington, DC 20307 USA
[5] Maastricht Univ, Dept Anat & Embryol, NL-6202 AZ Maastricht, Netherlands
[6] Cleveland Clin, Dept Pain Management, Cleveland, OH 44106 USA