Burst or High-Frequency (10 kHz) Spinal Cord Stimulation in Failed Back Surgery Syndrome Patients With Predominant Back Pain: One Year Comparative Data

Objectives: Burst and 10 kHz spinal cord stimulation (SCS) demonstrated improvement for failed back surgery syndrome (FBSS) with predominant, refractory back pain. Here, we report the long-term follow-up of a previously published study comparing the safety and efficacy of burst vs. 10 kHz SCS for predominant back pain (70% of global pain) of FBSS patients. Methods: This comparative, observational study extended the follow-up period up to 20 months evaluating both SCS modalities. Pain intensity (visual analog scale [VAS(B), VAS(L)]), functional capacity (Pittsburgh Sleep Quality Index [PSQI]; depression (Beck Depression Inventory [BDI]), stimulation parameters and hardware and/or stimulation associated adverse events were recorded and analyzed over time. Results: Overall VASB (t(1,12)566.76, p<0.001) and VASL (t(1,12)54.763, p<0.049; p<0.001) declined over time. Burst significantly decreased VAS(B) by 87.5% (+/- 17.7) (mean 8 +/- 0.76 to 1 +/- 1.41; t(1)512.3, p<0.001), and 10 kHz significant decreased VAS(B) by 54.9% (+/- 44) (mean 8 +/- 0.63 to 3.5 +/- 3.27; t(1)=3.09, p=0.027). No significant differences for between SCS types were revealed (t(1)=1.75, p=0.13). VAS(L) was significantly suppressed for burst (burst: 3.6 +/- 1.59 to 1.5 +/- 1.06; t(1)=53.32, p=0.013). A significant effect of time was found for functional outcome with no significant differences between SCS types (PSQI: t(1,12)=8.8, p=0.012; and BDI: t(1)=53.3, p<0.001). No stimulation/hardware-related complications occurred. Discussion: Long-term data of this comparative study suggests that burst responsiveness was superior to 10 kHz in our small-scale cohort, thus a larger, randomized-controlled comparative study design is highly recommended.