The Challenge of Converting “Failed Spinal Cord Stimulation Syndrome” Back to Clinical Success, Using SCS Reprogramming as Salvage Therapy, Through Neurostimulation Adapters Combined with 3D-Computerized Pain Mapping Assessment. A Real-Life Retrospective Cohort Analysis

Abstract

While paresthesia-based spinal cord stimulation (SCS) has been proven effective to treat chronic neuropathic pain, initial benefits may lead to the development of “Failed SCS Syndrome’ (FSCSS) defined as decrease over time related to Loss of Efficacy (LoE) with or without Loss of Coverage (LoC). Development of technologies associating new paresthesia-free stimulation waveforms and implanted pulse generator adapters provide opportunities to manage patients with LoE. The main goal of our study was to investigate salvage procedures, through neu-rostimulation adapters, in patients already implanted with SCS and experienced LoE. We retro-spectively analyzed a cohort of patients who were offered new SCS programs/waveforms through an implanted adapter between 2018 and 2021. Patients were evaluated before, and at 1, 3, 6 and 12-month follow-up. Outcomes included pain intensity rating with Visual Analog Scale (VAS), pain/coverage mappings and stimulation preferences. Last follow-up evaluations (N=27) showed significant improvement in VAS (p = 0.0001), ODI (p = 0.021) and Quality of Life (p=0.023). In the 11/27 patients with LoC, SCS efficacy on pain intensity (36.89%) was accompa-nied by paresthesia coverage recovery (55.57%) and pain surface decrease (47.01%). At 12-month follow-up, 81.3% preferred to keep tonic stimulation in their waveform portfolio. SCS conver-sion using adapters appears promising as a salvage solution, with an emphasis on paresthesia recapturing enabled by spatial retargeting. In light of these results, adapters could be integrated to SCS rescue algorithms or should be considered in SCS rescue.

The Added Value of Subcutaneous Peripheral Nerve Field Stimulation Combined with SCS, as Salvage Therapy, for Refractory Low Back Pain Component in Persistent Spinal Pain Syndrome Implanted Patients: A Randomized Controlled Study (CUMPNS Study) Based on 3D-Mapping Composite Pain Assessment

“…Burst stimulation appeared in 2013 [58], paresthesia free-high frequency techniques were developed contemporarily and it took about 5 years for our community to publish counter-studies, counterbalancing the "overly promising" initial results of some of these techniques [59][60][61][62], the objective being to orient us toward the right compromise for our patients, mixing the two approaches as complementary tools: (i) Spatial resolution can be adjusted by the choice of the neural target and new programing capabilities, based on electrical fragmentation of the current; and (ii) temporal resolution can be adjusted by the IPG, as an alternative to tonic conventional SCS or a combination of several waveforms delivered to the patient, the objective being to enhance our ability to personalize SCS therapies [2,63]. As a consequence, some recently marketed adapters play on the temporal resolution of SCS and give the patient the opportunity to extensively test the different existing waveforms with promising results [64][65][66]. These new insights need to be integrated in our approach to reflect the state of the art, since this paper's ambition is to propose a salvage algorithm.…”

Patient Selection for Spinal Cord Stimulation in Treatment of Pain: Sequential Decision-Making Model — A Narrative Review

“…As widely acknowledged in this field and despite the inclusion of a temporary SCS-screening trial before IPG implantation, the initial effectiveness of SCS generally declines over time, due to growing tolerance of the central nervous system, 47 which eventually causes loss of efficacy. As such, long-term pain coverage with SCS is not observed in up to 30% of patients, 48 , 49 for whom salvage therapy (ie, reprogramming toward another stimulation paradigm and even conversion to alternative SCS devices 50 , 51 ) could be applied. Despite the promising results of salvage therapy, clinicians are again confronted with selection criteria to determine the exact stimulation parameters to be programmed as salvage therapy (ie, to convert a clinical failure back to SCS success).…”