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

Abstract

While Spinal Cord Stimulation (SCS) provides satisfaction to almost 2/3 of Persistent Spinal Pain Syndrome-Type 2 (PSPS-T2) patients implanted for refractory chronic back and/or leg pain, when not adequately addressed the back pain component, leaves patients in a therapeutic cul-de-sac. Peripheral Nerve field Stimulation (PNfS) has shown interesting results addressing back pain in the same population. Far from placing these two techniques in opposition, we suggest that these approaches could be combined to better treat PSPS-T2 patients. We designed a RCT (CUMPNS), with a 12-month follow-up, to assess the potential added value of PNfS, as a salvage therapy, in PSPS-T2 patients experiencing a “Failed SCS Syndrome” in the back pain component. Fourteen patients were included in this study and randomized into 2 groups (“SCS + PNfS” group/n = 6 vs. “SCS only” group/n = 8). The primary objective of the study was to compare the percentage of back pain surface decrease after 3 months, using a computerized interface to obtain quantitative pain mappings, combined with multi-dimensional SCS outcomes. Back pain surface decreased significantly greater for the ”SCS + PNfS” group (80.2% ± 21.3%) compared to the “SCS only” group (13.2% ± 94.8%) (p = 0.012), highlighting the clinical interest of SCS + PNfS, in cases where SCS fails to address back pain.

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 Study

“…When patients are experiencing SCS LoE over time, several options can be discussed in a multidisciplinary pain reassessment, such as lead revision [ 24 ] or Internal Pulse Generator (IPG) upgrade [ 18 , 19 , 24 , 37 , 39 , 40 ]. Thanks to recent advances in SCS hardware and programming technologies, patients can have access to various waveforms (standard rate, high frequency (HF), burst, high dose (HD)) [ 16 , 33 , 37 , 41 , 42 ] and tailored advanced targeting (multisource IPG) [ 17 , 18 ] of the chronic pain experienced by SCS-implanted patients [ 43 , 44 ].…”

“…), we could wonder if the potential new IPG, implanted following a positive lead trial, would not interfere with the other neurostimulation targets. Ongoing studies [ 53 ] and recent publications [ 24 ] consider this important question. We should note that one of the advantages of this new technology is to propose four channels of stimulation, with a multi-source generation of the current.…”

“…The pixels of the patient’s drawing were then converted to cm², using several anatomical landmarks, patient morphology and morphometry, to optimally and accurately measure the pain area, using a patented data processing system (Patent Applications N° PCT/EP2014/067231, N° PCT/FR 14/000 186 and N° PCT/FR 14/000 187) [ 21 ]. The pain mapping software provides objective and reproducible measurements about the total pain surface and pain surface related to pain intensity expressed in cm², paresthesia coverage as the percentage of pain surface covered by paresthesia and the typology of pain ( Figure 1 ) [ 21 , 22 , 23 , 24 ]. Paresthesia coverage was considered as adequate when the paresthesia performance was greater than 60% (i.e., when at least 60% of the pain surface was covered with paresthesia).…”

Combining Awake Anesthesia with Minimal Invasive Surgery Optimizes Intraoperative Surgical Spinal Cord Stimulation Lead Placement

“…MAST allowed us to perform SCS surgical implantation under Target Controlled Intra-Veinous Anesthesia (TCIVA), making it possible to assess the patient intraoperatively with high-fidelity despite surgical lead invasiveness. Intra-operative testing using quantitive measurements of pain surface, pain intensity, pain typology, and paresthesia coverage was implemented through an interactive tactile interface specifically developed for this purpose [16, [29][30][31][32]. The mapping tool and software (Neuro-Mapping Locator TM / NML) provide novel indices to instantaneously assess / compare lead performance (percentage of pain area covered by paresthesia generated via SCS) and lead selectivity (percentage of paresthesia adequately overlapping painful territories) defining an "R index", with intraoperative objective data.…”

Advances in Neuromodulation for Chronic Pain

“…The first step towards the holy grail is to walk the extra mile for every patient, even for those who do not respond anymore to the initial paradigm. Salvage strategies and algorithms are gaining interest from researchers and clinicians [8][9][10][11][12][13]. Salvage therapy should not only consist of converting patients towards new paradigms but also introducing extra tools to regain freedom and independence in terms of patient empowerment.…”