• The primary endpoint is reduction in baseline levels of pain;
  
• The primary safety endpoint is the incidence of adverse events during the study period.
  

• Pain severity after 26, 40, and 52 weeks of treatment (for each treatment option) as compared to baseline;
  
• Percent of subjects with a 50% or greater reduction in pain;
  
• Percent of subjects crossing over to alternative treatment option;
  
• Average pain severity;
  
• Number of days with moderate to severe pain;
  
• Number of days using pain medication for pain;
  
• Quality of life;
  
• Days lost from work, work productivity loss, and total disability loss.
  

Standard medical treatment for moderate/severe chronic pain of Complex Regional Pain Syndrome (CRPS) is usually inadequate. Sympathetic nerve blocks with local anesthetics are commonly employed and in some cases can be an effective option. Nerve blocks are not consistently effective, however, and their utility is further compromised by a short duration of relief.

CRPS is among the pain etiologies that can be managed via Spinal Cord Stimulation (SCS); this option can be quite effective at providing long-term pain relief for the management of CRPS. Importantly, SCS is not usually attempted until other treatment options, including nerve blocks and ablative procedures, have failed to produce adequate pain relief. No studies have been performed to date comparing SCS to a series of nerve block injections plus physical therapy. In this context, it may be prudent to consider SCS earlier in the treatment continuum. Instead of obliging a CRPS patient to cycle through numerous rounds of injections, optimal clinical pain management may be attained through early implantation of an SCS system. This prospective clinical study will compare the relative efficacy of SCS with that of repeated nerve blocks and physical therapy in a group of subjects with moderate-to-severe CRPS pain.

Patients who have never had invasive treatments for CRPS pain will be randomized to either a series of sympathetic blocks plus physical therapy or SCS. Changes in pain, disability, and quality of life outcomes will be assessed at follow up visits as well as incidence and outcomes of subjects electing to cross over to the alternate treatment option. This study will generate insight into the best pain management strategies for CRPS.