Challenges to setting spinal cord stimulator parameters during intraoperative testing: factors affecting coverage of low back and leg pain.

Objective.  Spinal cord stimulator (SCS) parameter settings have been well studied; however, the goal of this exploratory study was to examine the SCS parameters used during intra-operative stimulation (IOS) at trial lead placement. Methods.  In this retrospective study, we report the IOS parameter settings for 22 patients who underwent thoracic SCS lead trial for treatment of refractory low back and/or leg pain. Results.  Paresthesia coverage was shown to differ depending upon the pain syndrome and the region involved (back and/or leg, p = 0.03). Certain stimulation parameters were demonstrated to be linked, including pulse width with rate (p = 0.04) and bipolar activation distance with amplitude (p < 0.01). Important variations in field configuration practice patterns also emerged. Conclusions.  Larger prospective studies are required to confirm and extend the current results. The ultimate goal for this report is to establish a foundation for future studies to create an evidence-based standardized algorithm for IOS to enhance the success rate of SCS trial screening.