Maximal Analgesic Effect Attained by the Use of Objective Neurophysiological Measurements With Closed-Loop Spinal Cord Stimulation.

OBJECTIVES: Spinal cord stimulation (SCS) has been challenged by the lack of neurophysiologic data to guide therapy optimization. Current SCS programming by trial-and-error results in suboptimal and variable therapeutic effects. A novel system with a physiologic closed-loop feedback mechanism using evoked-compound action potentials enables the optimization of physiologic neural dose by consistently and accurately activating spinal cord fibers. We aimed to identify neurophysiologic dose metrics and their ranges that resulted in clinically meaningful treatment responses. MATERIALS AND METHODS: Subjects from 3 clinical studies (n = 180) with baseline back and leg pain ≥60 mm visual analog scale and physical function in the severe to crippled category were included. Maximal analgesic effect (MAE) was operationally defined as the greatest percent reduction in pain intensity or as the greatest cumulative responder score (minimal clinically important differences [MCIDs]) obtained within the first 3 months of SCS implant. The physiologic metrics that produced the MAE were analyzed. RESULTS: We showed that a neural dose regimen with a high neural dose accuracy of 2.8µV and dose ratio of 1.4 resulted in a profound clinical benefit to chronic pain patients (MAE of 79 ± 1% for pain reduction and 12.5 ± 0.4 MCIDs). No differences were observed for MAE or neurophysiological dose metrics between the trial phase and post-implant MAE visit. CONCLUSION: For the first time, an evidence-based neural dose regimen is available for a neurostimulation intervention as a starting point to enable optimization of clinical benefit, monitoring of adherence, and management of the therapy.

Comparing Conventional Medical Management to Spinal Cord Stimulation for the Treatment of Low Back Pain in a Cohort of DISTINCT RCT Patients.

Aim: Low Back Pain (LBP) is a prevalent condition. Spinal cord stimulation (SCS) has emerged as a more effective, long-term treatment compared to conventional medical management (CMM). The DISTINCT study enrolled and randomized chronic LBP patients with no indication of traditional spine surgery. This analysis focuses comparing study outcomes on patients initially randomized to receive CMM treatment and subsequently crossed over to SCS after 6 months. Purpose: To compare the therapeutic effectiveness and cost-efficiency of passive recharge burst SCS to CMM. Patients and Methods: A total of 269 patients were enrolled with 162 randomly assigned to SCS and 107 to CMM. The DISTINCT study design allowed a crossover to the alternative treatment arm after 6 months. Patients underwent a trial and received a permanent implant if they reported ≥50% pain reduction. Outcome analysis included pain (NRS), disability (ODI), catastrophizing (PCS), quality of life (PROMIS-29) and health care utilization. Results: Seventy out of eighty-one patients opted to cross over to trial SCS at 6M with 94% (66/70) undergoing a trial. Among those, 88% (58/66) reported a ≥50% or more pain relief and 55 received a permanent implant. At 12M visit, 71.4% reported a ≥50% pain improvement sustained at the 18M visit, with 24.5% (12/49) indicating a ≥80% improvement. Disability reductions (79% meeting the minimally important difference of a 13-point decrease), decreased catastrophizing, and significant improvements in all PROMIS-29 domains were noted. Furthermore, 42% of the patients reported decreased or discontinued opioid usage. Clinical benefits at the 12M visit were sustained through the 18M visit accompanied by a significant reduction in healthcare utilization and a $1214 cost savings. Conclusion: SCS demonstrates superior, long-term performance and safety outcomes compared to CMM therapy in LBP patients who received both CMM and SCS therapy. Additionally, SCS patients experienced reduced healthcare resource utilization and lower costs compared to those receiving CMM.

Computational models for improving surveillance for the early detection of direct introduction of cassava brown streak disease in Nigeria.

Cassava is a key source of calories for smallholder farmers in sub-Saharan Africa but its role as a food security crop is threatened by the cross-continental spread of cassava brown streak disease (CBSD) that causes high yield losses. In order to mitigate the impact of CBSD, it is important to minimise the delay in first detection of CBSD after introduction to a new country or state so that interventions can be deployed more effectively. Using a computational model that combines simulations of CBSD spread at both the landscape and field scales, we model the effectiveness of different country level survey strategies in Nigeria when CBSD is directly introduced. We find that the main limitation to the rapid CBSD detection in Nigeria, using the current survey strategy, is that an insufficient number of fields are surveyed in newly infected Nigerian states, not the total number of fields surveyed across the country, nor the limitation of only surveying fields near a road. We explored different strategies for geographically selecting fields to survey and found that early and consistent CBSD detection will involve confining candidate survey fields to states where CBSD has not yet been detected and where survey locations are allocated in proportion to the density of cassava crops, detects CBSD sooner, more consistently, and when the epidemic is smaller compared with distributing surveys uniformly across Nigeria.

Surgical treatment of refractory low back pain using implanted BurstDR spinal cord stimulation (SCS) in a cohort of patients without options for corrective surgery: Findings and results from the DISTINCT study, a prospective randomized multi-center-controlled trial.

Background: Low back pain (LBP) is a highly prevalent, disabling condition affecting millions of people. Patients with an identifiable anatomic pain generator and resulting neuropathic lower extremity symptoms often undergo spine surgery, but many patients lack identifiable and/or surgically corrective pathology. Nonoperative treatment options often fail to provide sustained relief. Spinal cord stimulation (SCS) is sometimes used to treat these patients, but the lack of level 1 evidence limits its widespread use and insurance coverage. The DISTINCT RCT study evaluates the efficacy of passive recharge burst SCS compared to conventional medical treatment (CMM) in alleviating chronic, refractory axial low back pain. Methods: This prospective, multicenter, randomized, study with an optional 6-month crossover involved patients who were not candidates for lumbar spine surgery. The primary and secondary endpoints evaluated improvements in low back pain intensity (NRS), back pain-related disability (ODI), pain catastrophizing (PCS), and healthcare utilization. Patients were randomized to SCS therapy or CMM at 30 US study sites. Results: The SCS arm reported an 85.3% NRS responder rate (≥ 50% reduction) compared to 6.2% (5/81) in the CMM arm. After the 6M primary endpoint, SCS patients elected to remain on assigned therapy and 66.2% (49/74) of CMM patients chose to trial SCS (crossover). At the 12M follow-up, SCS and crossover patients reported 78.6% and 71.4% NRS responder rates. Secondary outcomes indicated significant improvements in ODI, PCS, and reduced healthcare utilization. Six serious adverse events were reported and resolved without sequelae. Conclusion: DISTINCT chronic low back pain patients with no indication for corrective surgery experienced a significant and sustained response to burst SCS therapy for up to 12 months. CMM patients who crossed over to the SCS arm reported profound improvements after 6 months. This data advocates for a timely consideration of SCS therapy in patients unresponsive to conservative therapy.

Developing Predictive Models and Early Warning Systems for Invading Pathogens: Wheat Rusts.

Innovations in aerobiological and epidemiological modeling are enabling the development of powerful techniques to infer connectivity networks for transboundary pathogens in ways that were not previously possible. The innovations are supported by improved access to historical and near real-time highly resolved weather data, multi-country disease surveillance data, and enhanced computing power. Using wheat rusts as an exemplar, we introduce a flexible modeling framework to identify characteristic pathways for long-distance spore dispersal within countries and beyond national borders. We show how the models are used for near real-time early warning systems to support smallholder farmers in East Africa and South Asia. Wheat rust pathogens are ideal exemplars because they continue to pose threats to food security, especially in regions of the world where resources for control are limited. The risks are exacerbated by the rapid appearance and spread of new pathogenic strains, prodigious spore production, and long-distance dispersal for transboundary and pandemic spread.

Long-Term Reductions in Opioid Medication Use After Spinal Stimulation: A Claims Analysis Among Commercially-Insured Population.

Purpose: Chronic, non-cancer pain significantly and negatively impacts patient quality of life. Neuromodulation is a major component of multi-modal interdisciplinary approaches to chronic pain management, which includes opioid and nonopioid medications. In randomized controlled trials, spinal cord stimulation (SCS) has been shown to reduce pain and decrease short-term opioid use for patients. This study sought to evaluate the effect of SCS on longer term opioid and non-opioid pain medication usage among patients over ≥3 years of follow-up. Patients and Methods: Claims analysis was conducted using the Merative™ MarketScan® Commercial Database. Patients aged ≥18 who initiated SCS between 1/1/2010 and 3/31/2021 with ≥1 year of baseline data and ≥3 years of follow-up data were included. Opioid discontinuation, daily dose (DD) reduction, proportion of days covered (PDC), concomitant co-medication with benzodiazepines and/or gabapentinoids, and polypharmacy were evaluated during the baseline and follow-up periods. Adjusted logistic regression was used to evaluate the impact of baseline dosages on discontinuation and dose reduction. Results: During follow-up, 60% of 2,669 SCS patients either discontinued opioid use or reduced opioid DD by at least 20% from baseline; another 15% reduced DD by 1-19%. Logistic regression showed patients with higher baseline dosages were less likely to discontinue opioids completely (odds ratio[OR] 95% confidence intervals[CI]: 0.31[0.18,0.54]) but more likely to reduce their daily dose (OR[CI]: 7.14[4.00,12.73], p<0.001). Mean PDC with opioids decreased from 0.58 (210 of 365 days) at baseline to 0.51 at year 3 (p<0.001). With SCS, co-medication with benzodiazepines decreased from 47.3% at baseline to 30.3% at year 3, co-medication with gabapentinoids reduced from 58.6% to 42.2%, and polypharmacy dropped from 15.6% to 9.6% (all p<0.001). Conclusion: Approximately three-quarters of patients who received SCS therapy either discontinued or reduced systemic opioid use over the study period. SCS could assist in reducing long-term reliance on opioids and other pain medications to treat chronic non-cancer pain.

Risk of adjacent level fracture after percutaneous vertebroplasty and kyphoplasty vs natural history for the management of osteoporotic vertebral compression fractures: a network meta-analysis of randomized controlled trials.

OBJECTIVES: Percutaneous vertebroplasty and kyphoplasty are common interventions for osteoporotic vertebral compression fractures. However, there is concern about an increased risk of adjacent-level fractures after treatment. This study aimed to compare the risk of adjacent-level fractures after vertebroplasty and kyphoplasty with the natural history after osteoporotic vertebral compression fractures. MATERIALS AND METHODS: A network meta-analysis of randomized controlled trials (RCTs) was conducted to evaluate the risk of adjacent-level fractures after vertebroplasty and kyphoplasty compared to the natural history after osteoporotic vertebral compression fractures. Frequentist network meta-analysis was conducted using the "netmeta" package, and heterogeneity was assessed using Q statistics. The pooled risk ratio (RR) and 95% confidence intervals (CI) were calculated using random effects. RESULTS: Twenty-three RCTs with a total of 2838 patients were included in the analysis. The network meta-analysis showed comparable risks of adjacent-level fractures between vertebroplasty, kyphoplasty, and natural history after osteoporotic vertebral compression fractures with a mean follow-up of 21.2 (range: 3-49.4 months). The pooled RR for adjacent-level fractures after kyphoplasty compared to natural history was 1.35 (95% CI, 0.78-2.34, p = 0.23) and for vertebroplasty compared to natural history was 1.16 (95% CI, 0.62-2.14) p = 0.51. The risk of bias assessment showed a low to moderate risk of bias among included RCTs. CONCLUSION: There was no difference in the risk of adjacent-level fractures after vertebroplasty and kyphoplasty compared to natural history after osteoporotic vertebral compression fractures. The inclusion of a large patient number and network meta-analysis of RCTs serve evidence-based clinical practice. CLINICAL RELEVANCE STATEMENT: The risk of adjacent-level fracture following percutaneous vertebroplasty or kyphoplasty is similar to that observed in the natural history after osteoporotic vertebral compression fractures. KEY POINTS: RCTs have examined the risk of adjacent-level fracture after intervention for osteoporotic vertebral compression fractures. There was no difference between vertebroplasty and kyphoplasty patients compared to the natural disease history for adjacent compression fractures. This is strong evidence that interventional treatments for these fractures do not increase the risk of adjacent fractures.

Network Meta-analysis and Economic Evaluation of Neurostimulation Interventions for Chronic Nonsurgical Refractory Back Pain.

OBJECTIVES: Different types of spinal cord stimulation (SCS) have been evaluated for the management of chronic nonsurgical refractory back pain (NSRBP). A direct comparison between the different types of SCS or between closed-loop SCS with conventional medical management (CMM) for patients with NSRBP has not been previously conducted, and therefore, their relative effectiveness and cost-effectiveness remain unknown. The aim of this study was to perform a systematic review, network meta-analysis (NMA) and economic evaluation of closed-loop SCS compared with fixed-output SCS and CMM for patients with NSRBP. METHODS: Databases were searched to September 8, 2023. Randomized controlled trials of SCS for NSRBP were included. The results of the studies were combined using fixed-effect NMA models. A cost-utility analysis was performed from the perspective of the UK National Health Service with results reported as incremental cost per quality-adjusted life-year (QALY). RESULTS: Closed-loop SCS resulted in statistically and clinically significant reductions in pain intensity (mean difference [MD] 32.72 [95% CrI 15.69-49.78]) and improvements in secondary outcomes (Oswestry Disability Index [ODI] and health-related quality of life [HRQoL]) compared with fixed-output SCS at 6-month follow-up. Compared with CMM, both closed-loop and fixed-output SCS resulted in statistically and clinically significant reductions in pain intensity (closed-loop SCS vs. CMM MD 101.58 [95% CrI 83.73-119.48]; fixed-output SCS versus CMM MD 68.86 [95% CrI 63.43-74.31]) and improvements in secondary outcomes (ODI and HRQoL). Cost-utility analysis showed that closed-loop SCS dominates fixed-output SCS and CMM, and fixed-output SCS also dominates CMM. DISCUSSION: Current evidence showed that closed-loop and fixed-output SCS provide more benefits and cost-savings compared with CMM for patients with NSRBP.

The Ethical Stewardship of Artificial Intelligence in Chronic Pain and Headache: A Narrative Review.

PURPOSE OF REVIEW: As artificial intelligence (AI) and machine learning (ML) are becoming more pervasive in medicine, understanding their ethical considerations for chronic pain and headache management is crucial for optimizing their safety. RECENT FINDINGS: We reviewed thirty-eight editorial and original research articles published between 2018 and 2023, focusing on the application of AI and ML to chronic pain or headache. The core medical principles of beneficence, non-maleficence, autonomy, and justice constituted the evaluation framework. The AI applications addressed topics such as pain intensity prediction, diagnostic aides, risk assessment for medication misuse, empowering patients to self-manage their conditions, and optimizing access to care. Virtually all AI applications aligned both positively and negatively with specific medical ethics principles. This review highlights the potential of AI to enhance patient outcomes and physicians' experiences in managing chronic pain and headache. We emphasize the importance of carefully considering the advantages, disadvantages, and unintended consequences of utilizing AI tools in chronic pain and headache, and propose the four core principles of medical ethics as an evaluation framework.

Application of restorative neurostimulation for chronic mechanical low back pain in an older population with 2-year follow up.

INTRODUCTION: Data on the Medicare-aged population show that older patients are major consumers of low back pain (LBP) interventions. An effective approach for patients with mechanical LBP that has been refractory to conservative management is restorative neurostimulation. The efficacy of restorative neurostimulation has been demonstrated in multiple prospective studies, with published follow-up over 4 years, showing a consistent durable effect. METHODS: To further examine the effect of restorative neurostimulation in an older demographic, data from three clinical studies were aggregated: ReActiv8-B prospectively followed 204 patients, ReActiv8-C study prospectively followed 87 patients and ReActiv8-PMCF prospectively followed 42 patients.Two hundred and sixty-one patients were identified with complete 2-year follow-up and divided into cohorts of equal size based of age quartiles.At 2 years from device activation, patients in either cohort were classified by change in disability (Oswestry Disability Index (ODI)) or change in pain score(NRS/VAS) and assessed as proportion of patients per group at each time point. Additionally, health-related quality of life (HRQoL) (EQ5D-5L) was longitudinally compared with baseline. Differences in proportions were assessed using χ2 and continuous variables by repeated measures analysis of variance. RESULTS: The oldest quartile (n=65) had a median age of 60 (56-82) years compared with the entire population (n=261) who had a median age of 49 (22-82) years. The completer analysis on patients with 2 years of continuous data showed improvement of a 50% in pain was achieved by 62% and 65% and a 15-point ODI improvement in 48% and 60% in the oldest quartile and entire population, respectively. HRQoL (EuroQol 5-Dimension) improved from baselines of 0.568 and 0.544 to 0.763 and 0.769 in the oldest quartile and entire population respectively. All age quartiles improved statistically and clinically over baseline. CONCLUSIONS: This aggregate analysis of three independent studies provides insight into the performance of restorative neurostimulation in an older population. Patients derived significant and clinically meaningful benefit in disability, pain and HRQoL. When compared with a similarly indicated cohort of younger patients, there were no statistically or clinically significant differences.

Five-Year Longitudinal Follow-Up of Restorative Neurostimulation Shows Durability of Effectiveness in Patients With Refractory Chronic Low Back Pain Associated With Multifidus Muscle Dysfunction.

BACKGROUND: Adults with refractory, mechanical chronic low back pain associated with impaired neuromuscular control of the lumbar multifidus muscle have few treatment options that provide long-term clinical benefit. This study hypothesized that restorative neurostimulation, a rehabilitative treatment that activates the lumbar multifidus muscles to overcome underlying dysfunction, is safe and provides relevant and durable clinical benefit to patients with this specific etiology. MATERIALS AND METHODS: In this prospective five-year longitudinal follow-up of the ReActiv8-B pivotal trial, participants (N = 204) had activity-limiting, moderate-to-severe, refractory, mechanical chronic low back pain, a positive prone instability test result indicating impaired multifidus muscle control, and no indications for spine surgery. Low back pain intensity (10-cm visual analog scale [VAS]), disability (Oswestry Disability Index), and quality of life (EuroQol's "EQ-5D-5L" index) were compared with baseline and following the intent-to-treat principle, with a supporting mixed-effects model for repeated measures that accounted for missing data. RESULTS: At five years (n = 126), low back pain VAS had improved from 7.3 to 2.4 cm (-4.9; 95% CI, -5.3 to -4.5 cm; p < 0.0001), and 71.8% of participants had a reduction of ≥50%. The Oswestry Disability Index improved from 39.1 to 16.5 (-22.7; 95% CI, -25.4 to -20.8; p < 0.0001), and 61.1% of participants had reduction of ≥20 points. The EQ-5D-5L index improved from 0.585 to 0.807 (0.231; 95% CI, 0.195-0.267; p < 0.0001). Although the mixed-effects model attenuated completed-case results, conclusions and statistical significance were maintained. Of 52 subjects who were on opioids at baseline and had a five-year visit, 46% discontinued, and 23% decreased intake. The safety profile compared favorably with neurostimulator treatments for other types of back pain. No lead migrations were observed. CONCLUSION: Over a five-year period, restorative neurostimulation provided clinically substantial and durable benefits with a favorable safety profile in patients with refractory chronic low back pain associated with multifidus muscle dysfunction. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02577354; registration date: October 15, 2016; principal investigator: Christopher Gilligan, MD, Brigham and Women's Hospital, Boston, MA, USA. The study was conducted in Australia (Broadmeadow, New South Wales; Noosa Heads, Queensland; Welland, South Australia; Clayton, Victoria), Belgium (Sint-Niklaas; Wilrijk), The Netherlands (Rotterdam), UK (Leeds, London, Middlesbrough), and USA (La Jolla, CA; Santa Monica, CA; Aurora, CO; Carmel, IN; Indianapolis, IN; Kansas City, KS; Boston, MA; Royal Oak, MI; Durham, NC; Winston-Salem, NC; Cleveland, OH; Providence, RI; Spartanburg, SC; Spokane, WA; Charleston, WV).

Telehealth and Virtual Reality Technologies in Chronic Pain Management: A Narrative Review.

PURPOSE OF REVIEW: This review provides medical practitioners with an overview of the present and emergent roles of telehealth and associated virtual reality (VR) applications in chronic pain (CP) management, particularly in the post-COVID-19 healthcare landscape. RECENT FINDINGS: Accumulated evidence points to the efficacy of now well-established telehealth modalities, such as videoconferencing, short messaging service (SMS), and mobile health (mHealth) applications in complementing remote CP care. More recently, and although still in early phases of clinical implementation, a wide range of VR-based interventions have demonstrated potential for improving the asynchronous remote management of CP. Additionally, VR-associated technologies at the leading edge of science and engineering, such as VR-assisted biofeedback, haptic technology, high-definition three-dimensional (HD3D) conferencing, VR-enabled interactions in a Metaverse, and the use of wearable monitoring devices, herald a new era for remote, synchronous patient-physician interactions. These advancements hold the potential to facilitate remote physical examinations, personalized remote care, and innovative interventions such as ultra-realistic biofeedback. Despite the promise of VR-associated technologies, several limitations remain, including the paucity of robust long-term effectiveness data, heterogeneity of reported pain-related outcomes, challenges with scalability and insurance coverage, and demographic-specific barriers to patient acceptability. Future research efforts should be directed toward mitigating these limitations to facilitate the integration of telehealth-associated VR into the conventional management of CP. Despite ongoing barriers to widespread adoption, recent evidence suggests that VR-based interventions hold an increasing potential to complement and enhance the remote delivery of CP care.

Factors Predicting Clinically Relevant Pain Relief After Spinal Cord Stimulation for Patients With Chronic Low Back and/or Leg Pain: A Systematic Review With Meta-Analysis and Meta-Regression.

RATIONALE: To optimize results with spinal cord stimulation (SCS) for chronic low back pain (CLBP) and/or leg pain, including persistent spinal pain syndrome (PSPS), careful patient selection based on proved predictive factors is essential. Unfortunately, the necessary selection process required to optimize outcomes of SCS remains challenging. OBJECTIVE: This review aimed to evaluate predictive factors of clinically relevant pain relief after SCS for patients with CLBP and/or radicular leg pain, including PSPS. MATERIALS AND METHODS: In August 2023, PubMed, Cinahl, Cochrane, and EMBASE were searched to identify studies published between January 2010 and August 2023. Studies reporting the percentage of patients with ≥50% pain relief after SCS in patients with CLBP and leg pain, including PSPS at 12 or 24 months, were included. Meta-analysis was conducted to pool results for back, leg, and general pain relief. Predictive factors for pain relief after 12 months were examined using univariable and multivariable meta-regression. RESULTS: A total of 27 studies (2220 patients) were included for further analysis. The mean percentages of patients with substantial pain relief were 68% for leg pain, 63% for back pain, and 73% for general pain at 12 months follow-up, and 63% for leg pain, 59% for back pain, and 71% for general pain at 24 months follow-up assessment. The implantation method and baseline Oswestry Disability Index made the multivariable meta-regression model for ≥50% back pain relief. Sex and pain duration made the final model for ≥50% leg pain relief. Variable stimulation and implantation method made the final model for general pain relief. CONCLUSIONS: This review supports SCS as an effective pain-relieving treatment for CLBP and/or leg pain, and models were developed to predict substantial back and leg pain relief. To provide high-grade evidence for predictive factors, SCS studies of high quality are needed in which standardized factors predictive of SCS success, based on in-patient improvements, are monitored and reported.

Regulatory Framework for Implantable Neurostimulation Devices: Comparison of Systems in the US and European Union.

BACKGROUND: Implantable neurostimulation devices must be authorized before they are placed on the market. For this purpose, requirements, and processes for assessing their fulfillment, have been defined in different jurisdictions. OBJECTIVE: In this study, we aimed to address differences between the US and European Union (EU) regulatory systems and their relationship to innovation. MATERIALS AND METHODS: A literature review and analysis were conducted using legal texts and guidance documents. RESULTS: The US system has one central body, the Food and Drug Administration, whereas the EU system has several bodies with different responsibilities. The devices themselves are divided into risk classes, which are based on the vulnerability of the human body. This risk class determines the intensity of the review by the market authorization body. In addition to the requirements for development, manufacture, and distribution, the device itself must meet technical and clinical requirements. Compliance with technical requirements is indicated by nonclinical laboratory studies. Proof of efficacy is provided by means of clinical investigations. Procedures are defined for reviewing these elements. Once the market authorization process has been completed, the devices can be placed on the market. In the postmarketing phase, the devices must continue to be monitored, and measures must be initiated, if necessary. CONCLUSIONS: Both US and EU systems are intended to ensure that only safe and effective devices find their way to and remain on the market. The basic approaches of the two systems are comparable. In detail, however, there are differences in ways these goals are achieved.