1. The Spine & Nerve Centers of the Virginias, Charleston, West Virginia
2. Department of Pain Management, Cleveland Clinic, Cleveland, Ohio
3. Michigan Pain Specialists, Ypsilanti, Michigan
4. Vidant Roanoke-Chowan Hospital, Ahoskie, North Carolina
5. Multidisciplinary Pain Program,Bronx, New York
6. Spine & Pain Institute of Florida, Lakeland, Florida
7. The University of Kansas Medical Center, Kansas City, Kansas, USA