[1] Univ Wisconsin, Sch Med & Publ Hlth, Madison, WI 53705 USA
[2] Univ Wisconsin Hlth, Dept Neurol, Madison, WI 53705 USA
[3] Kansas Pain Management & Neurosci Res Ctr, Kansas City, KS 66214 USA
[4] Swiss Pain Inst, CH-1003 Lausanne, Switzerland
[5] Univ Wisconsin Hlth, Dept Anesthesiol, Madison, WI 53705 USA