Effects of electrode positioning on perception threshold and paresthesia coverage in spinal cord stimulation

Objectives.  This pilot study aims to validate the hypothesis that a smaller distance between spinal cord stimulation (SCS) lead and spinal cord results in more extensive paresthesia and less energy consumption. Materials and Methods.  After insertion of a percutaneous SCS lead in patients with chronic pain (condition A), a first catheter was temporarily placed alongside the lead (condition B), and a second catheter was placed on the other side of the lead (condition C). In all three conditions paresthesia coverage, perception threshold (PT) of paresthesia, and maximum comfortable (MC) stimulus amplitude were determined and the catheters were subsequently removed. Results.  Paresthesia coverage in all six patients was increased markedly in condition C when compared to condition A, whereas the mean values of PT, MC, and therapeutic range (MC/PT) dropped by 22%, 14%, and 13%, respectively. Conclusions.  The results suggest that paresthesia coverage is increased when the space between the SCS lead and spinal cord gets smaller, whereas PT and energy consumption are reduced.