BACKGROUND/IMPORTANCE:Both percutaneous and paddle leads are utilized when implanting spinal cord stimulation (SCS). Both leads appear to be safe and effective, yet, there is a scarcity of guidelines for deciding which type of lead a physician should use. OBJECTIVE:The main goal is to provide an overview of clinical indications for percutaneous and paddle leads for SCS in patients with chronic spinal pain. EVIDENCE REVIEW:Databases consulted for this systematic review were PubMed, Web of Science, Scopus and Embase. Only studies evaluating SCS in chronic spinal pain patients, with or without previous spine surgery, were eligible. The study protocol was prospectively registered (PROSPERO, CRD42022347329). FINDINGS:Of the 102 included studies, 66.67% studies (n=68) implanted percutaneous leads, 30.4% (n=31) paddle leads and 2.9% (n=3) paddle leads with a percutaneous approach. Percutaneous leads are implanted when patients have no anatomic abnormalities, including no previous spinal interventions at the target location or thoracolumbar junction, and no previous experience with SCS or intrathecal drug delivery. Percutaneous leads may be considered for patients without a history of spinal surgery. Paddle leads are preferred when percutaneous lead placement is technically too difficult, including patients with a history of previous spine surgeries, or as a rescue therapy for failed percutaneous trials. CONCLUSIONS:Lead-specific indications were revealed for patients with chronic spinal pain, yet, the experience of the physician or affiliated department is suggested to have an important role. A clinical flowchart is proposed to help physicians in the decision-making process in daily clinical practice. PROSPERO REGISTRATION NUMBER:CRD42022347329.

Effectiveness of Occipital Nerve Stimulation (ONS) in refractory chronic cluster headache (rCCH) is supported by series of cases and a unique controlled trial, and its risk/benefit ratio has been questioned. Our objective was to identify predictive factors of ONS effectiveness in rCCH patients, to optimize this risk/benefit ratio and better select eligible patients. We analyzed 125 patients (43 women, mean age 46,4) included prospectively in the “French ONS registry”, suffering from rCCH, treated by ONS for more than one year, and with data concerning putative preoperative predictive factors of effectiveness, including demographic, CCH characteristics and severity, treatment use and co-morbidities. We studied factors associated with ONS response, defined as a ≥ 50

BACKGROUND:Persistent spinal pain syndrome Type 2 (PSPS-T2) is a long-lasting condition that consists of persistent pain following spinal surgery. Although this condition has long-term effects, it is currently studied at a given time point or over a limited period of time, which does not reflect the true impact of pain patients. To bridge this gap, we used latent class trajectory models to extract clusters with different trajectories of patients with PSPS-T2. MATERIALS AND METHODS:Data from the PREDIBACK study, an observational, multicentric, and longitudinal investigation carried out prospectively, were used. This study focuses on patients with PSPS-T2, tracking their outcomes at 3-month intervals over a one-year period. Health status was evaluated using a novel multidimensional clinical response index (MCRI). The trajectories of patients' health status were extracted using mixture of mixed effect models. RESULTS:Two hundred (200) PSPS-T2 patients were included. Two clusters were identified, including 'persistent low health' trajectories (63.1%) and 'improving health' trajectories (36.9%). Regarding the factors associated with these trajectories, our results showed that lower age, lower body mass index, lower pain intensity, lower functional disability, lower anxiety and less extended pain surface were associated with improving health status. CONCLUSION:Clustering methods provide an opportunity to identify two distinct clusters of pain-related health trajectories of PSPS-T2 patients. Persistence of the symptoms was not observed in one third of the PSPS-T2 study patients, who belong to the improving pain-related health cluster, while the other two thirds did not achieve improved health over a 1-year follow-up. SIGNIFICANCE STATEMENT:Our study findings suggest that the use of trajectory-based methods could improve patient evaluation and pain management as it allows for obtaining a global view of patients during their care pathway compared to conventional methods, which only focus on specific visits. Our study also advocates for multidimensional assessment and management of pain by targeting not only pain intensity but also the psychological distress, functional capacity and pain surface at an early stage of pain onset after spine surgery.

La douleur chronique, définie par l’IASP comme une expérience sensorielle et émotionnelle désagréable durant plus de trois mois, est un problème mondial majeur touchant des milliards de personnes et entraînant des coûts économiques significatifs. La douleur chronique impacte la qualité de vie des patients en affectant les dimensions psychologiques, sociales et fonctionnelles, bien au-delà de l’intensité perçue de la douleur. De récentes études ont notamment souligné l’importance d’une approche d’évaluation multidimensionnelle, intégrant non seulement l’intensité de la douleur, mais aussi ses répercussions sur les fonctions motrices, l’état mental et la qualité de vie globale. L’avènement des technologies numériques a ouvert de nouvelles perspectives dans l’évaluation de la douleur, notamment grâce à des outils comme le bodychart numérique. Cet outil permet de localiser et quantifier les surfaces douloureuses sur une application numérique présentant un avatar adapté au poids et la taille du patient, offrant une visualisation précise et rapide des zones douloureuses. Une étude a démontré la reproductibilité des données obtenues avec cet outil, ainsi que la complémentarité entre l’intensité et la surface de la douleur, fournissant des informations distinctes et essentielles pour optimiser l’évaluation de l’état de santé des patients. Ces solutions numériques sont particulièrement utiles pour documenter les réponses thérapeutiques et personnaliser les traitements. Dans cette logique, des scores composites intégrant plusieurs dimensions de la douleur, tels que le Multidimensional Clinical Response Index (MCRI), ont été développés. Le MCRI combine les paramètres de l’intensité de la douleur, la surface douloureuse, la qualité de vie et les aspects psychologiques, pour fournir une évaluation multidimensionnelle de la santé du patient. Ce score, basé sur des algorithmes de machine learning, offre une sensibilité et une spécificité élevées pour mesurer l’évolution de la douleur et l’efficacité des traitements. Malgré ces avancées, des limites subsistent. L’application de scores composites peut parfois masquer des dimensions importantes nécessitant une analyse indépendante. Leur intégration dans des outils numériques accessibles pourrait transformer la prise en charge de la douleur, notamment grâce à des applications mobiles facilitant le suivi à domicile et en téléconsultation. En conclusion, une évaluation multidimensionnelle et objective de la douleur, soutenue par l’innovation numérique et l’intelligence artificielle, offre une meilleure compréhension et prise en charge de la douleur chronique. Ces approches modernes, combinées avec la médecine personnalisée, pourraient significativement améliorer la qualité de vie des patients tout en réduisant les coûts liés à leur prise en charge.

Affecting millions of people, spinal pain is the leading cause of years lived with disability worldwide since the nineties. Centralization phenomenon (CP) and directional preference (DP) are common features in spinal pain patients, indicating a good clinical prognosis. CP is defined as a rapid and lasting migration of distal pain from the limb to the center of the spine after repeated movement tests. DP is a broader concept in which both the migration and decrease of pain are considered. While their detection has still been based on clinician decision, digital tool would provide objective measurements. We developed and assessed the reliability and validity of a new algorithm to detect CP and DP among spinal pain patients using quantitative a pain mapping software (PRISMAP). We designed a two-phase retrospective, cross-sectional, double-blinded diagnostic accuracy study. In Phase 1, using PRISMAP, we recorded and analyzed pain variations before and after a CP-focused physiotherapy session with specialized physiotherapy (PT). PTs classified patients as CP+ or CP-. We developed an algorithm to model changes in pain topography and intensity, identifying patients relative to PT classification. In Phase 2, PTs conducted four pain mappings. The initial two maps depicted a three-day overall patient pain profile, from which reliability and agreement were calculated using Intraclass Coefficient Correlation (ICC), Standard Error of Measurement (SEM), Coefficient of Variation (CV), and Bland-Altman analysis (BA). PTs then documented t-time pain mapping pre- and post-repeated movement test, classifying patients into CP-/CP+ and DP-/DP+. Validity parameters (sensitivity, specificity, positive and negative likelihood ratios (LR+/LR-)) were calculated from the latter two maps, using PT classification as the standard reference. Twelve patients were included in Phase 1 and 49 in Phase 2. The algorithm demonstrated good reliability (ICC=0.993 [95%CI 0.988–0.996], SEM=0.211, CV=12.2%, and bias error with the BA of -0.041 representing 2.4% of the sample mean). Validity for CP was 92.0% [95%CI 73.7–99.02], 79.2% [95%CI 57.8–92.9], 4.42 [95%CI 2.01–9.71], 0.1 [95%CI 0.03–0.39] for sensitivity, specificity, LR+, and LR-. Validity for DP was 81.3% [95%CI 63.56–92.79], 88.2% [95%CI 63.6–98.5], 6.91 [1.86–25.66], and 0.21 [95%CI 0.1–0.45] for sensitivity, specificity, LR+, and LR-. The mathematical modeling of CP and DP is reliable and valid. This approach may enhance patient selection for future studies and serve as a clinical aid for practitioners.

IntroductionRecent evidence supports the contribution of gut microbiota dysbiosis to the pathophysiology of rheumatic diseases, neuropathic pain, and neurodegenerative disorders. The bidirectional gut-brain communication network and the occurrence of chronic pain both involve contributions of the autonomic nervous system and the hypothalamic pituitary adrenal axis. Nevertheless, the current understanding of the association between gut microbiota and chronic pain is still not clear. Therefore, the aim of this study is to systematically evaluate the existing knowledge about gut microbiota alterations in chronic pain conditions.MethodsFour databases were consulted for this systematic literature review: PubMed, Web of Science, Scopus, and Embase. The Newcastle-Ottawa Scale was used to assess the risk of bias. The study protocol was prospectively registered at the International prospective register of systematic reviews (PROSPERO, CRD42023430115). Alpha-diversity, β-diversity, and relative abundance at different taxonomic levels were summarized qualitatively, and quantitatively if possible.ResultsThe initial database search identified a total of 3544 unique studies, of which 21 studies were eventually included in the systematic review and 11 in the meta-analysis. Decreases in alpha-diversity were revealed in chronic pain patients compared to controls for several metrics: observed species (SMD= -0.201, 95% CI from -0.04 to -0.36, p=0.01), Shannon index (SMD= -0.27, 95% CI from -0.11 to -0.43, p<0.001), and faith phylogenetic diversity (SMD -0.35, 95% CI from -0.08 to -0.61, p=0.01). Inconsistent results were revealed for beta-diversity. A decrease in the relative abundance of the Lachnospiraceae family, genus Faecalibacterium and Roseburia, and species of Faecalibacterium prausnitzii and Odoribacter splanchnicus, as well as an increase in Eggerthella spp., was revealed in chronic pain patients compared to controls.DiscussionIndications for gut microbiota dysbiosis were revealed in chronic pain patients, with non-specific disease alterations of microbes.Systematic review registrationhttps://www.crd.york.ac.uk/prospero/, identifier CRD42023430115.

Abstract Objective For many medical professionals dealing with patients with persistent pain following spine surgery, the term Failed back surgery syndrome (FBSS) as a diagnostic label is inadequate, misleading, and potentially troublesome. It misrepresents causation. Alternative terms have been suggested, but none has replaced FBSS. The International Association for the Study of Pain (IASP) published a revised classification of chronic pain, as part of the new International Classification of Diseases (ICD-11), which has been accepted by the World Health Organization (WHO). This includes the term Chronic pain after spinal surgery (CPSS), which is suggested as a replacement for FBSS. Methods This article provides arguments and rationale for a replacement definition. In order to propose a broadly applicable yet more precise and clinically informative term, an international group of experts was established. Results 14 candidate replacement terms were considered and ranked. The application of agreed criteria reduced this to a shortlist of four. A preferred option—Persistent spinal pain syndrome—was selected by a structured workshop and Delphi process. We provide rationale for using Persistent spinal pain syndrome and a schema for its incorporation into ICD-11. We propose the adoption of this term would strengthen the new ICD-11 classification. Conclusions This project is important to those in the fields of pain management, spine surgery, and neuromodulation, as well as patients labeled with FBSS. Through a shift in perspective, it could facilitate the application of the new ICD-11 classification and allow clearer discussion among medical professionals, industry, funding organizations, academia, and the legal profession.

INTRODUCTION:Occipital nerve stimulation (ONS) is proposed to treat refractory chronic cluster headache (rCCH), but its cost-effectiveness has not been evaluated, limiting its diffusion and reimbursement. MATERIALS AND METHODS:We performed a before-and-after economic study, from data collected prospectively in a nation-wide registry. We compared the cost-effectiveness of ONS associated with conventional treatment (intervention and postintervention period) to conventional treatment alone (preintervention period) in the same patients. The analysis was conducted on 76 rCCH patients from the French healthcare perspective at three months, then one year by extrapolation. Because of the impact of the disease on patient activity, indirect cost, such as sick leave and disability leave, was assessed second. RESULTS:The average total cost for three months was €7602 higher for the ONS strategy compared to conventional strategy with a gain of 0.07 quality-adjusted life-years (QALY), the incremental cost-effectiveness ratio (ICER) was then €109,676/QALY gained. The average extrapolated total cost for one year was €1344 lower for the ONS strategy (p = 0.5444) with a gain of 0.28 QALY (p < 0.0001), the ICER was then €-4846/QALY gained. The scatter plot of the probabilistic bootstrapping had 80% of the replications in the bottom right-hand quadrant, indicating that the ONS strategy is dominant. The average indirect cost for three months was €377 lower for the ONS strategy (p = 0.1261). DISCUSSION:This ONS cost-effectiveness study highlighted the limitations of a short-time horizon in an economic study that may lead the healthcare authorities to reject an innovative strategy, which is actually cost-effective. One-year extrapolation was the proposed solution to obtain results on which healthcare authorities can base their decisions. CONCLUSION:Considering the burden of rCCH and the efficacy and safety of ONS, the demonstration that ONS is dominant should help its diffusion, validation, and reimbursement by health authorities in this severely disabled population.