Papers of the Week

Refractory Persistent Spinal Pain Syndrome after surgery (PSPS-T2) can be successfully addressed by Spinal Cord Stimulation (SCS). While conventional stimulation generates paraesthesia, recent systems enable delivery of paresthesia-free stimulation. Studies have claimed non-inferiority/superiority of selected paresthesia-free stimulation compared with paresthesia-based stimulation, but the comparative efficacy between different waveforms still needs to be determined in a given patient. We designed a randomized controlled 3-month crossover trial to compare pain relief of paresthesia-based stimulation versus high frequency versus burst in 28 PSPS-T2 patients implanted with multiwave SCS systems. Our secondary objectives were to determine the efficacy of these three waveforms on pain surface, quality of life, functional capacity, psychological distress and validated composite Multidimensional Clinical Response Index (MCRI) to provide holistic comparisons at 3-, 6-, 9-, and 15-months post-randomization. The preferred stimulation modality was documented during the follow-up periods. No difference between the waveforms was observed in this study (p=0.08). SCS led to significant pain relief, quality of life improvement, improvement of MCRI and of all other clinical outcomes at all follow-up visits. Forty-four percent of the patients chose to keep the paresthesia-based stimulation modality after the 15-month follow-up period. By giving the possibility to switch and/or to combine several waveforms, the overall rate of SCS responders further increased with 25%. In this study, high frequency or burst do not appear superior to paresthesia-based stimulation, wherefore paresthesia-based stimulation should still be considered as a valid option. However, combining paresthesia-based stimulation with paresthesia-free stimulation, through personalized multiwave therapy, might significantly improve SCS responses. PERSPECTIVE: This article assesses clinical SCS efficacy on pain relief, by comparing paresthesia-based stimulation and paresthesia-free stimulation (including high frequency and burst) modalities in patient presenting with PSPS-T2. Switching and/or combining waveforms contribute to increase the global SCS responders rate.