Examining the Type, Quality, and Content of Web-Based Information for People With Chronic Pain Interested in Spinal Cord Stimulation: Social Listening Study.

BACKGROUND: The increased availability of web-based medical information has encouraged patients with chronic pain to seek health care information from multiple sources, such as consultation with health care providers combined with web-based information. The type and quality of information that is available on the web is very heterogeneous, in terms of content, reliability, and trustworthiness. To date, no studies have evaluated what information is available about neuromodulation on the web for patients with chronic pain. OBJECTIVE: This study aims to explore the type, quality, and content of web-based information regarding spinal cord stimulation (SCS) for chronic pain that is freely available and targeted at health care consumers. METHODS: The social listening tool Awario was used to search Facebook (Meta Platforms, Inc), Twitter (Twitter, Inc), YouTube (Google LLC), Instagram (Meta Platforms, Inc), blogs, and the web for suitable hits with "pain" and "neuromodulation" as keywords. Quality appraisal of the extracted information was performed using the DISCERN instrument. A thematic analysis through inductive coding was conducted. RESULTS: The initial search identified 2174 entries, of which 630 (28.98%) entries were eventually withheld, which could be categorized as web pages, including news and blogs (114/630, 18.1%); Reddit (Reddit, Inc) posts (32/630, 5.1%); Vimeo (Vimeo, Inc) hits (38/630, 6%); or YouTube (Google LLC) hits (446/630, 70.8%). Most posts originated in the United States (519/630, 82.4%). Regarding the content of information, 66.2% (383/579) of the entries discussed (fully discussed or partially discussed) how SCS works. In total, 55.6% (322/579) of the entries did not elaborate on the fact that there may be >1 potential treatment choice and 47.7% (276/579) did not discuss the influence of SCS on the overall quality of life. The inductive coding revealed 4 main themes. The first theme of pain and the burden of pain (1274/8886, 14.34% coding references) explained about pain, pain management, individual impact of pain, and patient experiences. The second theme included neuromodulation as a treatment approach (3258/8886, 36.66% coding references), incorporating the background on neuromodulation, patient-centered care, SCS therapy, and risks. Third, several device-related aspects (1722/8886, 19.38% coding references) were presented. As a final theme, patient benefits and testimonials of treatment with SCS (2632/8886, 29.62% coding references) were revealed with subthemes regarding patient benefits, eligibility, and testimonials and expectations. CONCLUSIONS: Health care consumers have access to web-based information about SCS, where details about the surgical procedures, the type of material, working mechanisms, risks, patient expectations, testimonials, and the potential benefits of this therapy are discussed. The reliability, trustworthiness, and correctness of web-based sources should be carefully considered before automatically relying on the content.

The Opinion of Healthcare Professionals About a Proposed European Registry of Neuromodulation for Chronic Pain: An Online Survey.

INTRODUCTION: During the last decade, the complementary value of real-world data (through registries or medical records) and data from randomized clinical trials has been recognized as increasingly important. In the field of neuromodulation, only a few industry-independent nationwide neuromodulation registries are available. The interest in creating a European registry has increased but without a successful result. The goal of this online survey is to gain further insights into the need for and burden of a European registry for neuromodulation. MATERIALS AND METHODS: An online survey was developed and distributed during the 3rd Joint Congress of the International Neuromodulation Society European Chapters in September 2023 (Hamburg, Germany). Healthcare professionals were asked to indicate the need for a European registry, the items that should be collected, and the restrictions to access of a European registry. RESULTS: In total, 125 respondents opened the link to the survey, of whom 104 completed (at least partly) the survey. Of the 104 responses, 91% indicated that there is a need for a European registry, whereas 6% indicated there is no need. The main reasons for establishing a registry on a European level were the possibility of collecting real-world evidence (84%), the potential to collect big data from European patients (82%), to evaluate safety in neuromodulation (70%), and the possibility of reporting yearly on European activity in neuromodulation (51%). Indications for neuromodulation, patient characteristics, and follow-up assessments were most often stated as items that should be collected. Access should not only be granted to implanters but also to nurses, the assessment team, and other physicians, as agreed on by 64%, 52%, and 51%, respectively. DISCUSSION: More than 90% of the respondents believed that a European registry for neuromodulation is needed, mainly to obtain real-world (big) data about the effectiveness and safety of this therapy. This survey clearly pointed to the need for a European registry for which it seems key to ensure financial and logistical support, in addition to in-depth legal guidance in developing this registry.

Socioeconomic Determinants of Initiating Neuromodulation for Chronic Pain: A Systematic Review.

OBJECTIVES: Neuromodulation is an effective treatment for chronic pain; however, socioeconomic differences may influence decision-making to initiate this therapy. This review investigated potential differences in accessibility of neuromodulation for patients with chronic pain due to socioeconomic determinants. MATERIALS AND METHODS: Four electronic databases were used for this systematic review: MEDLINE, Embase, Scopus, and Web of Science. Risk of bias was assessed using the modified version of the Downs and Black checklist. The study protocol was prospectively registered on PROSPERO (CRD42023426035). RESULTS: The initial database search identified a total of 1118 unique studies, of which 36 were eventually included in the systematic review. Of the 36 included studies, six studies reported on education, 24 on employment status, ten on insurance, five on household income, and three on miscellaneous topics. Neuromodulation seems accessible for patients with different education levels and different types of insurance. Additionally, it is not restricted to patients who are (un)employed. When comparing patients who initiated neuromodulation with those who did not, a significantly higher number of patients in the top quartile for education were found in the group without neuromodulation. Regarding insurance, inconclusive evidence was found. CONCLUSIONS: Although neuromodulation was accessible for patients with varying levels of socioeconomic determinants, disparities were noted. When comparing the socioeconomic profiles of patients who receive neuromodulation and those who do not, education levels differ. Health-related inequality should be carefully monitored in chronic pain management with neuromodulation to ensure that potential disparities do not increase.

Opinions of Health Care Providers About Neuromodulation for Pain: Results of an Online Survey at the 2nd Joint Congress of the International Neuromodulation Society European Chapters.

INTRODUCTION: Neuromodulation for pain has been successfully applied for decades, in that the goals and expectations that patients aim to achieve are clearly described. Nevertheless, the point of view of health care providers is less clear. Therefore, this study aimed to explore the goals, expectations, and definition of success for neuromodulation for pain according to health care providers. MATERIALS AND METHODS: An online survey was developed and spread at the 2nd Joint Congress of the International Neuromodulation Society (INS) European Chapters in September 2021 in Paris. Respondents were asked 1) to select the goals to treat patients with neuromodulation for pain, 2) to indicate factors that they expect to change according to neuromodulation for pain, and 3) to provide their definition of success of neuromodulation for pain. RESULTS: We approached 101 respondents, of whom 88 health care providers at least partly completed the survey. Increasing mobility/functionality (26.7%), decreasing pain intensity (24.5%), and decreasing medication use (16.6%) were the most frequently reported goals of neuromodulation. The same top three variables were selected as factors that health care providers expected to change. For the definition of success, quality of life of patients outranked other definitions. Other highly ranked definitions, in descending order, were obtaining pain relief, increasing functionality, and increasing patient satisfaction. DISCUSSION: Goals and expectations of health care providers are not completely in line with previously explored goals of patients that are related to pain relief and improving walking abilities. Health care providers seem to put a high emphasis on the quality of life of the patient when evaluating the success of neuromodulation, which is not completely aligned with the currently used reimbursement rules that are mainly focusing on pain relief instead of incorporating health-related quality of life. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT05013840.

Spinal Cord Stimulation-Naïve Patients vs Patients With Failed Previous Experiences With Standard Spinal Cord Stimulation: Two Distinct Entities or One Population?

INTRODUCTION: Nowadays, the success of spinal cord stimulation (SCS) is evaluated separately in patients who have previous experiences with standard SCS and in SCS-naïve patients. Nevertheless, it is yet to be evaluated whether both patient groups are effectively distinct patient groups. Therefore, the aims of this study are twofold: 1) Are there clusters in the data to distinguish between both patient groups? 2) Can we discriminate both patient groups based on routinely collected clinical parameters? MATERIALS AND METHODS: Baseline data from the Discover study were used, in which 263 patients with persistent spinal pain syndrome type 2 were included (185 neurostimulation-naïve patients and 78 patients with previous SCS experience). Pain intensity scores for low back and leg pain, functional disability, medication use, and health-related quality of life utility scores were used in the analysis. Model-based clustering was performed on standardized data. Discriminant analysis was performed with linear and quadratic discriminant analysis, with leave-one-out cross-validation to evaluate model performance. RESULTS: Model-based clustering revealed two different clusters in the data. None of the clusters clearly separated SCS-naïve patients from patients with previous SCS experience. Linear discriminant analysis resulted in a leave-one-out cross-validation error rate of 30.0% to discriminate between both patient groups, based on routinely collected clinical parameters. CONCLUSIONS: Clustering analysis did not result in clusters that separate SCS-naïve patients from patients with previous SCS experience. This may suggest that both patient groups should not be considered as two different patient groups when comparing them on routine clinical parameters, with potentially profound implications for research and clinical settings. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the Discover study is NCT02787265.

Acceptance and Commitment Therapy to Increase Resilience in Chronic Pain Patients: A Clinical Guideline.

Chronic pain remains a very difficult condition to manage for healthcare workers and patients. Different options are being considered and a biopsychosocial approach seems to have the most benefit, since chronic pain influences biological, psychological and social factors. A conservative approach with medication is the most common type of treatment in chronic pain patients; however, a lot of side effects are often induced. Therefore, a premium is set on novel nonpharmacological therapy options for chronic pain, such as psychological interventions. Previous research has demonstrated that resilience is a very important aspect in coping with chronic pain. A more recent type of cognitive-behavioural therapy is Acceptance and Commitment Therapy, in which psychological flexibility is intended to be the end result. In this manuscript, current evidence is used to explain why and how a comprehensive and multimodal treatment for patients with chronic pain can be applied in clinical practice. This multimodal treatment consists of a combination of pain neuroscience education and cognitive-behavioural therapy, more specifically Acceptance and Commitment Therapy. The aim is to provide a clinical guideline on how to contribute to greater flexibility and resilience in patients with chronic pain.

How Should we Use Multicolumn Spinal Cord Stimulation to Optimize Back Pain Spatial Neural Targeting? A Prospective, Multicenter, Randomized, Double-Blind, Controlled Trial (ESTIMET Study).

BACKGROUND: Recent studies have highlighted multicolumn spinal cord stimulation (SCS) efficacy, hypothesizing that optimized spatial neural targeting provided by new-generation SCS lead design or its multicolumn programming abilities could represent an opportunity to better address chronic back pain (BP). OBJECTIVE: To compare multicolumn vs. monocolumn programming on clinical outcomes of refractory postoperative chronic BP patients implanted with SCS using multicolumn surgical lead. MATERIALS AND METHODS: Twelve centers included 115 patients in a multicenter, randomized, double-blind, controlled trial. After randomization, leads were programmed using only one or several columns. The primary outcome was change in BP visual analogic scale (VAS) at six months. All patients were then programmed using the full potential of the lead up until 12-months follow-up. RESULTS: At six months, there was no significant difference in clinical outcomes whether the SCS was programmed using a mono or a multicolumn program. At 12 months, in all patients having been receiving multicolumn SCS for at least six months (n = 97), VAS decreases were significant for global pain (45.1%), leg pain (55.8%), and BP (41.5%) compared with baseline (p < 0.0001). CONCLUSION: The ESTIMET study confirms the significant benefit experienced on chronic BP by patients implanted with multicolumn SCS, independently from multicolumn lead programming. These good clinical outcomes might result from the specific architecture of the multicolumn lead, giving the opportunity to select initially the best column on a multicolumn grid and to optimize neural targeting with low-energy requirements. However, involving more columns than one does not appear necessary, once initial spatial targeting of the "sweet spot" has been achieved. Our findings suggest that this spatial concept could also be transposed to cylindrical leads, which have drastically improved their capability to shape the electrical field, and might be combined with temporal resolution using SCS new modalities.

Comparison of Spinal Cord Stimulation vs. Dorsal Root Ganglion Stimulation vs. Association of Both in Patients with Refractory Chronic Back and/or Lower Limb Neuropathic Pain: An International, Prospective, Randomized, Double-Blinded, Crossover Trial (BOOST-DRG Study).

While spinal cord stimulation (SCS) is a well-established therapy to address refractory persistent spinal pain syndrome after spinal surgery (PSPS-T2), its lack of spatial selectivity and reported discomfort due to positional effects can be considered as significant limitations. As alternatives, new waveforms, such as burst stimulation and different spatial neural targets, such as dorsal root ganglion stimulation (DRGS), have shown promising results. Comparisons between DRGS and standard SCS, or their combination, have never been studied on the same patients. "BOOST DRG" is the first prospective, randomized, double-blinded, crossover study to compare SCS vs. DRGS vs. SCS+DRGS. Sixty-six PSPS-T2 patients will be recruited internationally in three centers. Before crossing over, patients will receive each stimulation modality for 1 month, using tonic conventional stimulation. After 3 months, stimulation will consist in switching to burst for 1 month, and patients will choose which modality/waveform they receive and will then be reassessed at 6 and 12 months. In addition to our primary outcome based on pain rating, this study is designed to assess quality of life, functional disability, psychological distress, pain surface coverage, global impression of change, medication quantification, adverse events, brain functional imaging and electroencephalography, with the objective being to provide a multidimensional insight based on composite pain assessment.

An algorithmic programming approach for back pain symptoms in failed back surgery syndrome using spinal cord stimulation with a multicolumn surgically implanted epidural lead: a multicenter international prospective study.

INTRODUCTION: Many studies have demonstrated the efficacy and the medical/economic value of epidural spinal cord stimulation for the treatment of "failed back surgery syndrome" (FBSS). However, the back pain component of FBSS has been recalcitrant. Recent clinical trials have suggested that multicolumn surgically implanted leads combined with enhanced programming capabilities in the newer implantable pulse generators demonstrate the ability to treat the back pain component of FBSS. The objective of our present international multicentre study is to prospectively evaluate these findings in a larger population. METHODS: We conducted a prospective, nonrandomized, observational study on 76 patients with refractory FBSS, consecutively implanted with multicolumn spinal cord stimulation (SCS) between 2008 and 2011 in three neurosurgical pain management centers (Poitiers, France; Montréal, Canada; and Regina, Canada). The primary objective of this study was to prospectively analyze the effect of multicolumn lead programming on paresthesia coverage for the back pain region in these patients. The secondary objective was to assess the analgesic efficacy of this technique on the global and back pain components. RESULTS: Paresthesia could be induced in the lower extremities in the majority of patients with at least one of the configurations tested. Bilateral low back paresthesia was induced in 53.5% of patients, while unilateral low back paresthesia was induced in 78.9% of patients. Multicolumn configurations were statistically more effective than monocolumn configurations for all anatomic regions studied. At 6 months, 75.4% of patients receiving multicolumn stimulation (n = 57) obtained at least a 30% improvement of the back pain VAS score, while 42.1% of patients obtained at least a 50% improvement of the back pain VAS score. CONCLUSION: This study confirms the hypothesis that multicolumn SCS should be considered as an important tool in the treatment of radicular and axial pain in FBSS patients. The efficacy of this modality is based on a rigorous patient selection process, access to new generation lead technologies, but most importantly an algorithmic programming approach for optimal stimulation and electrical field shaping. With over 40 million potential programming combinations associated with 16 contact leads to achieve paresthesia coverage, optimal stimulation is often missed as either the patient or the clinician become exhausted or overwhelmed during the course of therapy programming and optimization session.

Gut dysbiosis in patients with chronic pain: a systematic review and meta-analysis.

Introduction: Recent 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. Methods: Four 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, ß-diversity, and relative abundance at different taxonomic levels were summarized qualitatively, and quantitatively if possible. Results: The 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. Discussion: Indications for gut microbiota dysbiosis were revealed in chronic pain patients, with non-specific disease alterations of microbes. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42023430115.

Effect of neuromodulation for chronic pain on the autonomic nervous system: a systematic review.

Background: In recent years, there has been a growing interest in the use of neuromodulation as an alternative treatment option for chronic pain. Neuromodulation techniques, such as spinal cord stimulation (SCS), dorsal root ganglion (DRG) stimulation, deep brain stimulation (DBS), and peripheral nerve stimulation, have shown promising results in the management of various chronic pain conditions and involve targeted modulation of neural activity to alleviate pain and restore functional capacity. The autonomic nervous system (ANS) plays a crucial role in the regulation of various bodily functions including pain perception. However, the effects of neuromodulation on the ANS in the context of chronic pain remain poorly understood. This systematic review aimed to comprehensively assess the existing literature about the effects of neuromodulation on the ANS in chronic pain settings. Methods: Searches were conducted using four electronic databases (PubMed, EMBASE, SCOPUS, and Web of Science). The study protocol was registered before initiation of the review process. The Office of Health Assessment and Translation (OHAT) Risk of Bias tool was used to evaluate risk of bias. Results: A total of 43 studies were included, of which only one was an animal study. Several studies have reported more than one outcome parameter in the same population of chronic pain patients. Cardiovascular parameters were the most frequently used outcomes. More specifically, 18 outcome parameters were revealed to evaluate the function of the ANS, namely heart rate variability (n=17), arterial blood pressure (n=15), tissue oxygenation/perfusion (n=5), blood markers (n=6), multiunit postganglionic sympathetic nerve activity (n=4), skin temperature (n=3), skin conductance (n=3), cephalic autonomic symptoms (n=2), ventilatory frequency (n=2), vasomotor tone (n=1), baroreflex sensitivity (n=1), sympathetic innervation of the heart, neural activity of intrinsic cardiac neurons (n=1), vascular conductance (n=1), arterial diameter (n=1), blood pulse volume (n=1), and vagal efficiency (n=1). Most studies evaluated SCS (62.79%), followed by DBS (18.6%), peripheral nerve stimulation (9.3%), DRG stimulation (4.65%), and vagus nerve stimulation (4.65%). Overall, inconsistent results were revealed towards contribution of SCS, DBS, and peripheral nerve stimulation on ANS parameters. For DRG stimulation, included studies pointed towards a decrease in sympathetic activity. Conclusions: There are indications that neuromodulation alters the ANS, supported by high or moderate confidence in the body of evidence, however, heterogeneity in ANS outcome measures drives towards inconclusive results. Further research is warranted to elucidate the indirect or direct mechanisms of action on the ANS, with a potential benefit for optimisation of patient selection for these interventions. Systematic review protocol: PROSPERO (CRD42021297287).

Proportion of clinical holistic responders in patients with persistent spinal pain syndrome type II treated by subthreshold spinal cord stimulation compared to best medical treatment: a study protocol for a multicentric randomised controlled trial (TRADITION).

BACKGROUND: Integrating information on bodily functions, pain intensity and quality of life into one composite measure of a holistic responder has recently been proposed as a useful method to evaluate treatment efficacy of spinal cord stimulation (SCS) in patients with therapy-refractory persistent spinal pain syndrome type II (PSPS-T2). Previous studies already demonstrated the efficacy of standard SCS over best medical treatment (BMT) and the superiority of new subthreshold (i.e. paresthesia free) SCS paradigms compared to standard SCS. Nevertheless, the efficacy of subthreshold SCS compared to BMT has not yet been investigated in patients with PSPS-T2, neither with unidimensional outcomes nor with a composite measure. The current objective is to examine whether subthreshold SCS, compared to BMT, provided to patients with PSPS-T2 results in a different proportion of clinical holistic responders (as composite measure) at 6 months. METHODS: A two-arm multicentre randomised controlled trial will be conducted whereby 114 patients will be randomised (1:1) to (a) BMT or (b) paresthesia-free SCS. After a follow-up period of 6 months (primary time endpoint), patients receive the opportunity to cross over towards the other treatment group. The primary outcome is the proportion of clinical holistic responders at 6 months (i.e. a composite measure of pain intensity, medication, disability, health-related quality of life and patient satisfaction). The secondary outcomes are work status, self-management, anxiety, depression and healthcare expenditure. DISCUSSION: Within the TRADITION project, we propose to shift the focus from a unidimensional outcome measure towards a composite measure as primary outcome measure to evaluate the efficacy of currently used subthreshold SCS paradigms. The lack of methodologically rigorous trials exploring the clinical efficacy and socio-economic consequences of subthreshold SCS paradigms is pressing, especially in light of the growing burden of PSPS-T2 on the society. TRIAL REGISTRATION: ClinicalTrials.gov NCT05169047. Registered on December 23, 2021.

Should we Oppose or Combine Waveforms for Spinal Cord Stimulation in PSPS-T2 Patients? A Prospective Randomized Crossover Trial (MULTIWAVE Study).

Refractory persistent spinal pain syndrome after surgery (PSPS-T2) can be successfully addressed by spinal cord stimulation (SCS). While conventional stimulation generates paresthesia, recent systems enable the 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 3 waveforms on pain surface, quality of life, functional capacity, psychological distress, and validated composite multidimensional clinical response index to provide holistic comparisons at 3-, 6-, 9-, and 15-month post-randomization. The preferred stimulation modality was documented during the follow-up periods. No difference between the waveforms was observed in this study (P = .08). SCS led to significant pain relief, quality of life improvement, improvement of multidimensional clinical response index, 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 increasing the global SCS responders rate.

Stand-alone kyphoplasty in recent thoracolumbar split fractures: A series of 36 patients reviewed at 19months.

INTRODUCTION: Spinal fractures with a split component present specific bone union problems (pseudarthrosis). The purpose of this study was to assess the rate of pseudarthrosis after stand-alone percutaneous kyphoplasties and analyze clinical and radiographic parameters that are predictive of its efficacy in thoracolumbar spine fractures with a split-type of injury. HYPOTHESIS: Stand-alone kyphoplasty results in satisfactory bone union of the treated vertebral body despite the diastasis of fracture fragments. MATERIALS AND METHODS: A retrospective single-center study of 36 patients with posttraumatic monosegmental thoracolumbar vertebral fractures, that were classified as either Magerl A2 or A3.2, without any neurologic deficits. Patients were treated with percutaneous kyphoplasty and PMMA bone cement. The assessment included both clinical (visual analog pain scale [VAS] and Oswestry disability index) and radiographic (pseudarthrosis, fracture gap, disk incarceration, vertebral height and length, and vertebral and regional kyphosis) criteria. RESULTS: A total of 36 patients (mean age 58years) were included, with a mean follow-up of 19.1months. Five of these patients (14%) had a pseudarthrosis. The fracture gap was significantly greater in these patients than in those who had bone union preoperatively (+3.94 mm, p<0.001) and at the last follow-up consultation (+9.3 mm, p<0.001). There was an association between the incarceration of adjacent disks located above (p=0.008) and below (p=0.003) the fracture site and the pseudarthrosis. The mean VAS decreased significantly on the first postoperative day (p<0.001) and remained lower than the initial assessment until the last follow-up (p<0.001). DISCUSSION: Stabilization by stand-alone kyphoplasty produces good clinical and radiographic results for split fractures, provided that the extent of the fragment diastasis has been carefully assessed preoperatively to prevent the risk of pseudarthrosis. LEVEL OF EVIDENCE: IV; retrospective.

Association between Experimental Pain Measurements and the Central Sensitization Inventory in Patients at Least 3 Months after COVID-19 Infection: A Cross-Sectional Pilot Study.

Fatigue, pain, headache, brain fog, anosmia, ageusia, mood symptoms, and sleep disorders are symptoms commonly experienced by people with post-COVID-19 condition. These symptoms could be considered as manifestations of central sensitization. The aim of this study is to evaluate whether there are indicators of central sensitization by using experimental pain measurements and to determine their association with patient-reported outcome measures (PROMs). A cross-sectional study including 42 patients after COVID-19 infection was conducted. The central sensitization inventory (CSI) was administered as a PROM to evaluate central-sensitization-associated symptoms. Pressure pain thresholds (PPT), temporal summation, and descending nociceptive pain inhibition (CPM) were assessed as experimental pain measurements. The median score on the CSI was 46.5 (Q1-Q3: 33-54). The presence of central-sensitization-associated symptoms was seen in 64.3% of patients based on the CSI (≥40/100 points). A deficient CPM was seen in 12% and 14% of patients when measured at the trapezius and rectus femoris, respectively. A negative correlation between pressure sensitivity on the rectus femoris and the CSI score (r = -0.36, 95%CI -0.13 to -0.65, p = 0.007) was observed. Central-sensitization-associated symptoms were present in up to 64.3% of patients post-COVID-19 infection, based on a PROM, i.e., the CSI. A more objective evaluation of nociceptive processing through experimental pain measurements was less suggestive of indicators of central sensitization. Only a small negative correlation between pressure sensitivity and the CSI was observed, thereby pointing towards the discrepancy between the CSI and experimental pain measurements and presumably the complementary need for both to evaluate potential indicators of central sensitization in this population.

"Neuro-Fiber Mapping": An Original Concept of Spinal Cord Neural Network Spatial Targeting Using Live Electrostimulation Mapping to (Re-)Explore the Conus Medullaris Anatomy.

Spinal cord (SC) anatomy is often assimilated to a morphologically encapsulated neural entity, but its functional anatomy remains only partially understood. We hypothesized that it could be possible to re-explore SC neural networks by performing live electrostimulation mapping, based on "super-selective" spinal cord stimulation (SCS), originally designed as a therapeutical tool to address chronic refractory pain. As a starting point, we initiated a systematic SCS lead programming approach using live electrostimulation mapping on a chronic refractory perineal pain patient, previously implanted with multicolumn SCS at the level of the conus medullaris (T12-L1). It appeared possible to (re-)explore the classical anatomy of the conus medullaris using statistical correlations of paresthesia coverage mappings, resulting from 165 different electrical configurations tested. We highlighted that sacral dermatomes were not only located more medially but also deeper than lumbar dermatomes at the level of the conus medullaris, in contrast with classical anatomical descriptions of SC somatotopical organization. As we were finally able to find a morphofunctional description of "Philippe-Gombault's triangle" in 19th-century historical textbooks of neuroanatomy, remarkably matching these conclusions, the concept of "neuro-fiber mapping" was introduced.

Heart rate variability is not suitable as a surrogate marker for pain intensity in patients with chronic pain.

ABSTRACT: The search towards more objective outcome measurements and consequently surrogate markers for pain started decades ago; however, no generally accepted biomarker for pain has qualified yet. The goal is to explore the value of heart rate variability (HRV) as surrogate marker for pain intensity chronic pain setting. Pain intensity scores and HRV were collected in 366 patients with chronic pain, through a cross-sectional multicenter study. Pain intensity was measured with both the visual analogue scale and numeric rating scale, whereas 16 statistical HRV parameters were derived. Canonical correlation analysis was performed to evaluate the correlation between the dependent pain variables and the HRV parameters. Surrogacy was determined for each HRV parameter with point estimates between 0 and 1 whereby values close to 1 indicate a strong association between the surrogate and the true endpoint at the patient level. Weak correlations were revealed between HRV parameters and pain intensity scores. The highest surrogacy point estimate was found for mean heart rate as marker for average pain intensity on the numeric rating scale with point estimates of 0.0961 (95% confidence interval [CI] 0.0384-0.1537) and 0.0209 (95% CI 0-0.05) for patients without medication use and with medication, respectively. This study indicated that HRV parameters as separate entities are no suitable surrogacy candidates for pain intensity, in a population of chronic pain patients. Further potential surrogate candidates and clinical robust true endpoints should be explored, to find a surrogate measure for the highly individual pain experience.

Evaluation of External Trigeminal Nerve Stimulation to Prevent Cerebral Vasospasm after Subarachnoid Hemorrhage Due to Aneurysmal Rupture: A Randomized, Double-Blind Proof-of-Concept Pilot Trial (TRIVASOSTIM Study).

Cerebral vasospasm remains the most frequent and devastating complication after subarachnoid aneurysmal hemorrhage because of secondary cerebral ischemia and its sequelae. The underlying pathophysiology involves vasodilator peptide release (such as CGRP) and nitric oxide depletion at the level of the precapillary sphincters of the cerebral (internal carotid artery network) and dural (external carotid artery network) arteries, which are both innervated by craniofacial autonomic afferents and tightly connected to the trigeminal nerve and trigemino-cervical nucleus complex. We hypothesized that trigeminal nerve modulation could influence the cerebral flow of this vascular network through a sympatholytic effect and decrease the occurrence of vasospasm and its consequences. We conducted a prospective double-blind, randomized controlled pilot trial to compare the effect of 10 days of transcutaneous electrical trigeminal nerve stimulation vs. sham stimulation on cerebral infarction occurrence at 3 months. Sixty patients treated for aneurysmal SAH (World Federation of Neurosurgical Societies scale between 1 and 4) were included. We compared the radiological incidence of delayed cerebral ischemia (DCI) on magnetic resonance imaging (MRI) at 3 months in moderate and severe vasospasm patients receiving trigeminal nerve stimulation (TNS group) vs. sham stimulation (sham group). Our primary endpoint (the infarction rate at the 3-month follow-up) did not significantly differ between the two groups (p = 0.99). Vasospasm-related infarctions were present in seven patients (23%) in the TNS group and eight patients (27%) in the sham group. Ultimately, we were not able to show that TNS can decrease the rate of cerebral infarction secondary to vasospasm occurrence. As a result, it would be premature to promote trigeminal system neurostimulation in this context. This concept should be the subject of further research.

Virtual Reality during Intrathecal Pump Refills in Children: A Case Series.

Virtual reality has proven to be an effective approach to decrease pain in acute settings, both in adults and children. The aim of this study is to evaluate whether virtual reality (VR) could reduce pain during an intrathecal pump refill procedure in children receiving intrathecal drug delivery, compared to a standard refill procedure. This is a three-arm crossover randomized controlled trial, evaluating the effect of VR on pain in children with cerebral palsy undergoing an intrathecal pump refill compared to a standard refill and a refill with distraction (watching a video). Pain was evaluated using the Wong-Baker Faces Scale. Secondary outcomes were procedural pain, fear, state anxiety, the incidence of adverse events and satisfaction. Six children participated in this study, whereby all children underwent the three conditions. Five children indicated an equal of lower pain score during VR, compared to a standard refill. This finding of an equal or lower pain intensity score for the VR condition compared to the control condition was also revealed by the ratings of the parents, physician and the researcher. The influence of VR on anxiety and fear seem to be in line with the influence of watching a video. In terms of satisfaction, all children and parents agreed with the statement that they would like to use VR again for a next refill. Due to the lack of adverse events, the high degree of satisfaction of children with VR and the decreased pain levels after a refill with VR, physicians may aim to explore the implementation of VR during intrathecal pump refill procedures in children in a daily clinical routine care setting.