Twenty patients with failed back surgery syndrome (FBSS) and a preexisting SCS system each received three treatment allocations in random order for a period of one week: 500-Hz tonic stimulation, burst stimulation, and placebo stimulation. The primary outcome measure was pain intensity measured on a numerical rating scale (NRS). Secondary outcome measures were pain quality measured using the Short Form McGill Pain Questionnaire (SFMPQ) and safety. Additional data were collected relating to pain-related disability measured using the Oswestry Disability Index (ODI).
The lowest mean NRS and SFMPQ scores were observed under burst stimulation. For the burst stimulation treatment group, mean NRS and SFMPQ scores were significantly decreased compared with the other treatment groups. Mean NRS and SFMPQ scores were not significantly different between 500-Hz tonic stimulation and placebo stimulation. Although the lowest mean ODI score was observed under burst stimulation, no significant differences were found between the ODI categories. No adverse events occurred, and burst stimulation was significantly preferred by 16 patients (80%).
Overall, burst stimulation resulted in significantly better pain relief and improved pain quality in the short term compared with 500-Hz tonic stimulation and placebo stimulation and was preferred by the majority of patients 1).