[1] Hosp Prof Doutor Fernando Fonseca Amadora, Dept Phys Med & Rehabil, P-2720276 Amadora, Portugal
[2] Univ Toronto, Univ Hlth Network, Toronto Western Hosp, Dept Anesthesiol & Pain Med, Toronto, ON M5T 2S8, Canada
[3] Mayo Clin, Dept Pain Med, Jacksonville, FL 32224 USA
[4] Mayo Clin, Dept Anesthesiol & Perioperat Med, Rochester, MN 55905 USA
[5] Mayo Clin, Dept Anesthesiol & Perioperat Med, Jacksonville, FL 32224 USA