Durability of Evoked Compound Action Potential (ECAP)-Controlled, Closed-Loop Spinal Cord Stimulation (SCS) in a Real-World European Chronic Pain Population.

INTRODUCTION: Closed-loop spinal cord stimulation (CL-SCS) is a recently introduced system that records evoked compound action potentials (ECAPs) from the spinal cord elicited by each stimulation pulse and uses this information to automatically adjust the stimulation strength in real time, known as ECAP-controlled SCS. This innovative system compensates for fluctuations in the distance between the epidural leads and the spinal cord by maintaining the neural response (ECAP) at a predetermined target level. This data collection study was designed to assess the performance of the first CL-SCS system in a real-world setting under normal conditions of use in multiple European centers. The study analyzes and presents clinical outcomes and electrophysiological and device data and compares these findings with those reported in earlier pre-market studies of the same system. METHODS: This prospective, multicenter, observational study was conducted in 13 European centers and aimed to gather electrophysiological and device data. The study focused on the real-world application of this system in treating chronic pain affecting the trunk and/or limbs, adhering to standard conditions of use. In addition to collecting and analyzing basic demographic information, the study presents data from the inaugural patient cohort permanently implanted at multiple European centers. RESULTS: A significant decrease in pain intensity was observed for overall back or leg pain scores (verbal numerical rating score [VNRS]) between baseline (mean ± standard error of the mean [SEM]; n = 135; 8.2 ± 0.1), 3 months (n = 93; 2.3 ± 0.2), 6 months (n = 82; 2.5 ± 0.3), and 12 months (n = 76; 2.5 ± 0.3). Comparison of overall pain relief (%) to the AVALON and EVOKE studies showed no significant differences at 3 and 12 months between the real-world data release (RWE; 71.3%; 69.6%) and the AVALON (71.2%; 73.6%) and EVOKE (78.1%; 76.7%) studies. Further investigation was undertaken to objectively characterize the physiological parameters of SCS therapy in this cohort using the metrics of percent time above ECAP threshold (%), dose ratio, and dose accuracy (µV), according to previously described methods. Results showed that a median of 90% (40.7-99.2) of stimuli were above the ECAP threshold, with a dose ratio of 1.3 (1.1-1.4) and dose accuracy of 4.4 µV (0.0-7.1), based on data from 236, 230, and 254 patients, respectively. Thus, across all three metrics, the majority of patients had objective therapy metrics corresponding to the highest levels of pain relief in previously reported studies (usage over threshold > 80%, dose ratio > 1.2, and error < 10 µV). CONCLUSIONS: In conclusion, this study provides valuable insights into the real-world application of the ECAP-controlled CL-SCS system, highlighting its potential for maintaining effective pain relief and objective neurophysiological therapy metrics at levels seen in randomized control trials, and potential for quantifying patient burden associated with SCS system use via patient-device interaction metrics. CLINICAL TRIAL REGISTRATION: In the Netherlands, the study is duly registered on the International Clinical Trials Registry Platform (Trial NL7889). In Germany, the study is duly registered as NCT05272137 and in the United Kingdom as ISCRTN27710516 and has been reviewed by the ethics committee in both countries.

Comparing the Efficacy of Dorsal Root Ganglion Stimulation With Conventional Medical Management in Patients With Chronic Postsurgical Inguinal Pain: Post Hoc Analyzed Results of the SMASHING Study.

OBJECTIVES: Approximately 10% of patients who undergo inguinal hernia repair or Pfannenstiel incision develop chronic (> three months) postsurgical inguinal pain (PSIP). If medication or peripheral nerve blocks fail, a neurectomy is the treatment of choice. However, some patients do not respond to this treatment. In such cases, stimulation of the dorsal root ganglion (DRG) appears to significantly reduce chronic PSIP in selected patients. MATERIALS AND METHODS: In this multicenter, randomized controlled study, DRG stimulation was compared with conventional medical management (CMM) (noninvasive treatments, such as medication, transcutaneous electric neurostimulation, and rehabilitation therapy) in patients with PSIP that was resistant to a neurectomy. Patients were recruited at a tertiary referral center for groin pain (SolviMáx, Eindhoven, The Netherlands) between March 2015 and November 2016. Suitability for implantation was assessed according to the Dutch Neuromodulation Association guidelines. The sponsor discontinued the study early owing to slow enrollment. Of 78 planned patients, 18 were randomized (DRG and CMM groups each had nine patients). Six patients with CMM (67%) crossed over to DRG stimulation at the six-month mark. RESULTS: Fifteen of the 18 patients met the six-month primary end point with a complete data set for a per-protocol analysis. Three patients with DRG stimulation had a negative trial and were lost to follow-up. The average pain reduction was 50% in the DRG stimulation and crossover group (from 6.60 ± 1.24 to 3.28 ± 2.30, p = 0.0029). Conversely, a 13% increase in pain was observed in patients with CMM (from 6.13 ± 2.24 to 6.89 ± 1.24, p = 0.42). Nine patients with DRG stimulation experienced a total of 19 adverse events, such as lead dislocation and pain at the implantation site. CONCLUSIONS: DRG stimulation is a promising effective therapy for pain relief in patients with PSIP resistant to conventional treatment modalities; larger studies should confirm this. The frequency of side effects should be a concern in a new study. CLINICAL TRIAL REGISTRATION: The Clinicaltrials.gov registration number for the study is NCT02349659.

A prospective study of BurstDR™ spinal cord stimulation for non-operated discogenic low back pain.

INTRODUCTION: Chronic discogenic low back pain (CD-LBP) is caused by degeneration of the disc due to trauma to the annulus or by unprovoked degeneration, resulting in chronic pain. Spinal cord stimulation (SCS) employing the BurstDR™ waveform has been shown to be an effective treatment in a variety of chronic pain conditions. The aim of this prospective case study was to determine the effect of BurstDR™ SCS on pain relief, disability, and patient satisfaction in a population with CD-LBP. METHODS: Seventeen subjects with CD-LBP received a SCS trial with BurstDR™ stimulation. Patients with >50% pain relief after a trial period of 2 weeks were permanently implanted (n = 15). Patients then rated LBP and leg pain using the numeric rating scale (NRS), Oswestry disability index (ODI), patient global impression of change (PGIC), EQ-5D quality of life, and painDETECT for neuropathic pain at baseline following trial, 3, 6, and 12 months after permanent implantation. RESULTS: Treatment with BurstDR™ SCS resulted in significant reduction of LBP as the NRS was reduced from 71.7 ± 7.3 at baseline to 42.5 ± 18.1 at 12 months. Average pain relief at 12 months was 42.5%. In patients with leg pain (n = 8), pain was significantly reduced from 66.9 ± 8.2 to 11.7 ± 10.4 at 12 months. PainDETECT scores for neuropathic pain significantly reduced from 18.9 ± 4.8 at baseline, and 14.8 ± 3.2 at 12 months. Baseline ODI score significantly reduced from 41.2 ± 12.8 to 25.8 ± 8.6 at 12 months. PGIC scores remained low from 2.6 ± 1.6 at 3 months, 2.5 ± 1.0 at 6 months, and 2.5 ± 1.3 at 12 months. EQ-5D-5L rates remained constant from baseline 56.10 ± 23.9 to 68.6 ± 12.9 at 12 months. CONCLUSION: BurstDR™ SCS resulted in significant reduction of back pain, leg pain, and quality of life in patients with CD-LBP and decreased the level of disability and generated positive patient satisfaction scores.

Study protocol: Effects of active versus passive recharge burst spinal cord stimulation on pain experience in persistent spinal pain syndrome type 2: a multicentre randomized trial (BURST-RAP study).

BACKGROUND: Spinal cord stimulation (SCS) has shown to be an effective treatment for patients with persistent spinal pain syndrome type 2 (PSPS Type 2). The method used to deliver electrical charge in SCS is important. One such method is burst stimulation. Within burst stimulation, a recharge pattern is used to prevent buildup of charge in stimulated tissues. Two variations of burst waveforms are currently in use: one that employs active recharge and one that uses passive recharge. It has been suggested that differences exist between active and passive recharge paradigms related to both efficacy of pain relief and their underlying mechanism of action. Active recharge has been shown to activate both the medial spinal pathway, engaging cortical sensorimotor areas involved in location and intensity of pain, and lateral pathway, reaching brain areas involved with cognitive-emotional aspects of pain. Passive recharge has been suggested to act via modulation of thalamic neurons, which fire in a similar electrical pattern, and thereby modulate activity in various cortical areas including those related to motivational and emotional aspects of pain. The objective of this randomized clinical trial is to assess and compare the effect of active versus passive recharge Burst SCS on a wide spectrum of pain in PSPS Type 2 patients. METHODS: This multicentre randomized clinical trial will take place in 6 Dutch hospitals. PSPS Type 2 patients (n=94) will be randomized into a group receiving either active or passive recharge burst. Following a successful trial period, patients are permanently implanted. Patients complete the Pain Catastrophizing Scale (PCS) (primary outcome at 6 months), Numeric Pain Rating Scale (NRS), Patient Vigilance and Awareness Questionnaire (PVAQ), Hospital Anxiety and Depression Scale (HADS), Quality of Life (EQ-5D), Oswestery Disability Index (ODI), Patient Global Impression of Change (PGIC) and painDETECT questionnaires (secondary outcomes) at baseline, after trial, 1, 3, 6 and 12 months following implantation. DISCUSSION: The BURST-RAP trial protocol will shed light on possible clinical differences and effectivity of pain relief, including emotional-motivational aspects between active and passive burst SCS in PSPS Type 2 patients. TRIAL REGISTRATION: ClinicalTrials.gov registration:  NCT05421273 . Registered on 16 June 2022. Netherlands Trial Register NL9194. Registered on 23 January 2021.

Evaluating value mediation in patients with chronic low-back pain using virtual reality: contributions for empirical research in Value Sensitive Design.

Value Sensitive Design (VSD) is the most well-known method to consider values in design. It consists of three iterative phases of investigation: conceptual, empirical, and technical. Although the approach is promising, the role of empirical research remains unclear. We address two opportunities for extending the role of empirical research in VSD. First, we argue that empirical research enables us to identify values in context. Second, we explain that empirical research enables us to anticipate how technology mediates the values of users. We make our point by means of an empirical study in a real-life controlled experimental context into the value mediation of virtual reality (VR) in patients with chronic low-back pain. Using value-oriented semi-structured interviews with twenty patients, we first analyze what values these patients consider important, and how the values are experienced. The second set of interviews held after all patients used VR four weeks at home, aims to provide insight into value changes as mediated by VR. We end the article by a comparison of our empirical results with previous, often speculative, literature into values in VR. We show that empirical research benefits the VSD process by providing in-depth insight into the effects of context and technology on values and the ability to translate these insights into recommendations for more responsible design and implementation of the technology. Supplementary information: The online version contains supplementary material available at 10.1007/s12553-022-00671-w.

Efficacy of the Gelstix nucleus augmentation device for the treatment of chronic discogenic low back pain: protocol for a randomised, sham-controlled, double-blind, multicentre trial.

INTRODUCTION: Discogenic pain is the cause of pain in 26%-40% of patients with for low back pain. Consensus about treatment of chronic discogenic low back pain is lacking and most treatment alternatives are supported by limited evidence. The percutaneous implantation of hydrogels into the nucleus pulposus represents a promising regenerative intradiscal therapy. The hydrogel 'GelStix' is composed primarily of hydrolyzed polyacrylonitrile and acts as a reservoir of hydration, producing increased pressure and improved pH balance, potentially leading to disc preservation. We hypothesise that treatment with GelStix will lead to greater reduction in pain intensity at 6 months post-treatment compared with patients receiving sham treatment. METHODS AND ANALYSIS: This is a parallel group, randomised sham-controlled double-blind, multicentre trial to assess whether the GelStix device is superior to sham in reducing pain intensity in patients with chronic discogenic low back pain. The study will be conducted in two regional hospitals in Europe. Seventy-two participants will be randomised in a 1:1 ratio. The primary outcome will be the change in pain intensity between preoperative baseline and at 6 months postintervention. Secondary outcomes were disability, quality of life, the patient's global impression of change scale, the use of pain medication and the disc degeneration process assessed by means of MRI. For change in pain intensity, disability, health-related quality of life and disc height, mean values will be compared between groups using linear regression analysis, adjusted for treatment centre. ETHICS AND DISSEMINATION: Ethics approval was obtained from the Ethics Committee of the Canton Ticino, Switzerland (CE2982) and by the Medical Ethical Committee Arnhem-Nijmegen, the Netherlands (2016-2944). All patients that agree to participate will be asked to sign an informed consent form. Results will be disseminated through international publications in peer-reviewed journals, in addition to international conference presentations. TRIAL REGISTRATION NUMBER: NCT02763956. PROTOCOL VERSION: 7.1, 18 November 2020.

[Whether or not to use gabapentinoids in adults with chronic neuropathic pain]. / Wel of geen gabapentinoïden bij volwassenen met chronische neuropathische pijn?

CASE DESCRIPTION: A frail 85-year-old woman with chronic neuropathic pain after hip surgery, not responding to treatment with acetaminophen and morphine patches. Should she be prescribed a gabapentinoid? DISCUSSION: Gabapentinoids and antidepressants are considered first-line therapies. They achieve clinically relevant (i.e. ≥ 50%) pain reduction in approximately one-third of patients with postherpetic neuralgia and peripheral diabetic neuropathy. Evidence for other types of neuropathic pain is limited. Adverse events occur frequently and are mostly mild in nature; serious adverse effects are rare. Prescription of gabapentinoids in specific patient groups (e.g. elderly patients and patients with a history of depression or substance abuse) deserves careful consideration, because the risk/benefit ratio in those groups may be altered. In order to reduce the risk of withdrawal symptoms, slow tapering is recommended. CONCLUSION: Chronic neuropathic pain often has a negative impact on the quality of life and is difficult to treat. In general, treatment with a gabapentinoid is a possible first-line treatment option. However, they may be relatively contraindicated in vulnerable patients.

Cost-Effectiveness of Radiofrequency Denervation for Patients With Chronic Low Back Pain: The MINT Randomized Clinical Trials.

OBJECTIVES: To evaluate the cost-effectiveness of radiofrequency denervation when added to a standardized exercise program for patients with chronic low back pain. METHODS: An economic evaluation was conducted alongside 3 pragmatic multicenter, nonblinded randomized clinical trials (RCTs) in The Netherlands with a follow up of 52 weeks. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain; a positive diagnostic block at the facet joints (n = 251), sacroiliac (SI) joints (n = 228), or a combination of facet joints, SI joints, and intervertebral discs (n = 202); and were unresponsive to initial conservative care. Quality-adjusted life-years (QALYs) and societal costs were measured using self-reported questionnaires. Missing data were imputed using multiple imputation. Bootstrapping was used to estimate statistical uncertainty. RESULTS: After 52 weeks, no difference in costs between groups was found in the facet joint or combination RCT. The total costs were significantly higher for the intervention group in the SI joint RCT. The maximum probability of radiofrequency denervation being cost-effective when added to a standardized exercise program ranged from 0.10 in the facet joint RCT to 0.17 in the SI joint RCT irrespective of the ceiling ratio, and 0.65 at a ceiling ratio of €30 000 per QALY in the combination RCT. CONCLUSIONS: Although equivocal among patients with symptoms in a combination of the facet joints, SI joints, and intervertebral discs, evidence suggests that radiofrequency denervation combined with a standardized exercise program cannot be considered cost-effective from a societal perspective for patients with chronic low back pain originating from either facet or SI joints in a Dutch healthcare setting.

Randomized controlled trials reflected clinical practice when comparing the course of low back pain symptoms in similar populations.

OBJECTIVE: This study compares participants in randomized controlled trials (RCTs) (the Minimal Invasive Treatment [MinT] trials) to participants in a related observational study with regard to their low back pain (LBP) symptom course. STUDY DESIGN AND SETTING: Eligible patients were diagnosed with chronic LBP originating from the facet joints (N = 615) or sacroiliac (SI) joints (N = 533) and were treated with radiofrequency denervation and an exercise program. Randomized patients were compared to patients in the related observational study who fulfilled all RCT eligibility criteria (observational group 1) and to patients who did not fulfill at least one of the RCT eligibility criteria (observational group 2). Outcomes were pain intensity, treatment success, and functional status over a 3-month period. Longitudinal mixed-model analyses and linear regression models were applied to analyze the differences in outcomes between the RCT and observational study groups. RESULTS: No differences in symptom course were found between patients in the RCTs and patients in observational group 1. Patients with facet joint pain in observational group 2 had overall less treatment success (odds ratios [OR], 0.67; 95% confidence interval [CI], 0.50-0.90), and less improvement in physical functioning (mean difference [MD], 5.82; 95% CI, 2.54-9.11) compared to the RCT patients. Patients with SI joint pain in observational group 2 had higher pain scores (MD, 0.40; 95% CI, 0.09-0.72), less treatment success (OR, 0.72; 95% CI, 0.54-0.96), and less improvement in physical functioning (MD, 7.16; 95% CI, 3.84-10.47) compared to the RCT patients. CONCLUSION: This supports the generalizability of results from the MinT RCTs as this study suggests that these RCTs reflect clinical practice when comparing similar populations. To what extent this holds true for all RCTs in LBP should be further explored.

The Impact of Chronic Discogenic Low Back Pain: Costs and Patients' Burden.

Introduction: Chronic discogenic low back pain (CDP) is frequently diagnosed in patients referred to specialized pain clinics for their back pain. The aim of this study is to assess the impact of CDP both on the individual patient and on society. Materials and Methods: Using the baseline records of 80 patients in a randomized trial assessing the effectiveness of a new intervention for CDP, healthcare and societal costs related to back pain are calculated. Furthermore, the impact of the condition on perceived pain, disability, health-related quality of life, Quality of life Adjusted Life Years (QALY), and QALY loss is assessed. Results: Using the friction costs approach, we found that the annual costs for society are €7,911.95 per CDP patient, 51% healthcare and 49% societal costs. When using the human capital approach, total costs were €18,940.58, 22% healthcare and 78% societal costs. Healthcare costs were mainly related to pain treatment. Mean pain severity was 6.5 (0-10), and 46% suffered from severe pain (≥7/10). Mean physical limitations rate was 43.7; 13.5% of the patients were very limited to disabled. QALY loss compared to a healthy population was 64%. Discussion: This study shows that in patients with CDP referred to a pain clinic, costs for society are high and the most used healthcare resources are pain therapies. Patients suffer severe pain, are physically limited, and experience a serious loss in quality of life.

Quality indicators to assess quality of pain clinic care from the perspective of patients with chronic pain: development, usability, comprehensibility, and psychometric quality of the QiPPP questionnaire.

To address the lack of appropriate patient-defined quality indicators (QIs) for assessment of pain clinic care in the Netherlands, we developed the "Quality Indicators Pain Patients' Perspective" (QiPPP) questionnaire. Quality indicators are widely used to measure the quality of the structure, process, and outcome of health care. The Pain Patient United Consortium, together with the University Pain Centre of Maastricht, developed QIs for assessment of care. The aim of this study was to develop QIs from the perspective of patients with chronic pain for assessment of the care provided by a pain clinic, and to validate them on usability, comprehensibility, and psychometric quality in daily pain practice. Quality as defined by patients with chronic pain (in survey and focus groups) was prioritized by consensus and transformed into QI. A first set was tested and fine-tuned, resulting in the QiPPP questionnaire. Five participating pain clinics distributed 200 questionnaires among consecutive patients with chronic pain under treatment. To examine the dimensionality of the QIs, patient responses were analyzed on the basis of reporting frequencies and findings of principal component analysis. For construct validation, the influence of patient characteristics was observed in 3 components. A total of 547 (54.7%) populated QiPPP questionnaires (response rate, 58.9%) were analyzed. The mean score for patient comprehensibility was 8.6 ± 1.4. The final QiPPP questionnaire included 21 QIs (18 process; 3 outcome) distributed over 7 domains. The QiPPP questionnaire was of sufficient psychometric quality and found to be useful and understandable by patients with chronic pain.

Pulsed Radiofrequency as a Minimally Invasive Treatment Option in Anterior Cutaneous Nerve Entrapment Syndrome: A Retrospective Analysis of 26 Patients.

BACKGROUND: Chronic abdominal pain is occasionally due to entrapped intercostal nerve endings (ACNES, abdominal cutaneous nerve entrapment syndrome). If abdominal wall infiltration using an anesthetic agent is unsuccessful, a neurectomy may be considered. Pulsed radiofrequency (PRF) is a relatively new treatment option for various chronic pain syndromes. Evidence regarding a beneficial effect of this minimally invasive technique in ACNES is lacking. The aim was to assess the effectiveness of PRF treatment in ACNES patients. METHODS: A series of ACNES patients undergoing PRF treatment between January 2014 and December 2015 in two hospitals were retrospectively evaluated. Pain was recorded prior to treatment and after 6 weeks using a numerical rating scale (NRS, 0 (no pain) to 10 (worst possible pain)). Successful treatment was defined as > 50% NRS pain reduction. Patient satisfaction was scored by patient global impression of change (PGIC, 1 = very much worse, to 7 = very much improved). RESULTS: Twenty-six patients were studied (17 women, median age 47 years, range 18 - 67 years). After 6 weeks, mean NRS score had dropped from 6.7 ± 1.2 to 3.8 ± 2.3 (P < 0.001). A mean 4.9 ± 1.4 PGIC score was reported by then. Short term treatment success (6 - 8 weeks) was 50% (n = 13, 95% CI: 29 - 71), while 8% was pain-free on the longer term (median 15 months). Median effect duration was 4 months (range 2 - 26). CONCLUSIONS: PRF is temporarily effective in half of patients with ACNES. PRF is safe and may be favored in neuropathic pain syndromes as nerve tissue destruction is possibly limited. A randomized controlled trial determining the potential additional role of PRF in the treatment strategy for ACNES is underway.

Effect of Radiofrequency Denervation on Pain Intensity Among Patients With Chronic Low Back Pain: The Mint Randomized Clinical Trials.

IMPORTANCE: Radiofrequency denervation is a commonly used treatment for chronic low back pain, but high-quality evidence for its effectiveness is lacking. OBJECTIVE: To evaluate the effectiveness of radiofrequency denervation added to a standardized exercise program for patients with chronic low back pain. DESIGN, SETTING, AND PARTICIPANTS: Three pragmatic multicenter, nonblinded randomized clinical trials on the effectiveness of minimal interventional treatments for participants with chronic low back pain (Mint study) were conducted in 16 multidisciplinary pain clinics in the Netherlands. Eligible participants were included between January 1, 2013, and October 24, 2014, and had chronic low back pain, a positive diagnostic block at the facet joints (facet joint trial, 251 participants), sacroiliac joints (sacroiliac joint trial, 228 participants), or a combination of facet joints, sacroiliac joints, or intervertebral disks (combination trial, 202 participants) and were unresponsive to conservative care. INTERVENTIONS: All participants received a 3-month standardized exercise program and psychological support if needed. Participants in the intervention group received radiofrequency denervation as well. This is usually a 1-time procedure, but the maximum number of treatments in the trial was 3. MAIN OUTCOMES AND MEASURES: The primary outcome was pain intensity (numeric rating scale, 0-10; whereby 0 indicated no pain and 10 indicated worst pain imaginable) measured 3 months after the intervention. The prespecified minimal clinically important difference was defined as 2 points or more. Final follow-up was at 12 months, ending October 2015. RESULTS: Among 681 participants who were randomized (mean age, 52.2 years; 421 women [61.8%], mean baseline pain intensity, 7.1), 599 (88%) completed the 3-month follow-up, and 521 (77%) completed the 12-month follow-up. The mean difference in pain intensity between the radiofrequency denervation and control groups at 3 months was -0.18 (95% CI, -0.76 to 0.40) in the facet joint trial; -0.71 (95% CI, -1.35 to -0.06) in the sacroiliac joint trial; and -0.99 (95% CI, -1.73 to -0.25) in the combination trial. CONCLUSIONS AND RELEVANCE: In 3 randomized clinical trials of participants with chronic low back pain originating in the facet joints, sacroiliac joints, or a combination of facet joints, sacroiliac joints, or intervertebral disks, radiofrequency denervation combined with a standardized exercise program resulted in either no improvement or no clinically important improvement in chronic low back pain compared with a standardized exercise program alone. The findings do not support the use of radiofrequency denervation to treat chronic low back pain from these sources. TRIAL REGISTRATION: trialregister.nl Identifier: NTR3531.

Efficacy and cost-effectiveness of intradiscal methylene blue injection for chronic discogenic low back pain: study protocol for a randomized controlled trial.

BACKGROUND: Low back pain (LBP) is a common health problem and a substantial part of LBP is presumed to be attributable to degeneration of the intervertebral disc. For patients suffering from intractable discogenic LBP, there are few evidence-based effective interventional treatment options available. In 2010, the results of a randomized controlled trial (RCT) were published concerning "intradiscal methylene blue injection" (IMBI), in which this intervention appeared to be very successful in relieving discogenic pain. Therefore, we decided to repeat this study to investigate whether we could replicate the published results. The results of our preliminary feasibility study gave reason to set up an RCT. The aim of this RCT is to evaluate if IMBI is a more effective treatment of discogenic low back pain as an intradiscal placebo intervention, and furthermore, to assess the cost-effectiveness of this intervention. METHODS/DESIGN: Consecutive discogenic low back pain patients referred to four specialized pain treatment facilities are being screened for eligibility. After a positive standardized provocation discography and informed consent, patients are randomized into two groups. The treatment group receives an intradiscal injection with methylene blue, lidocaine, and contrast, and the control group receives intradiscal isotonic saline with lidocaine and contrast. Main outcome measures are pain at the 6-month follow-up, patient's global impression of change, cost-effectiveness, quality of life, disability, and analgesic intake. DISCUSSION: The importance of this study is emphasized by the fact that for intractable discogenic low back pain patients, evidence-based effective pain treatments are rare. If this study establishes clinical success and cost-effectiveness, IMBI could become the "pain treatment of choice" for a selected group of patients with chronic discogenic low back pain for whom noninvasive treatment options have failed. TRIAL REGISTRATION: National Trial register NTR2547 Registered at 29 September 2010 and 31 March 2014.

Targeted methylprednisolone acetate/hyaluronidase/clonidine injection after diagnostic epiduroscopy for chronic sciatica: a prospective, 1-year follow-up study.

BACKGROUND AND OBJECTIVES: It has been claimed that epiduroscopy offers an ideal combination of diagnostic and therapeutic interventions in one session. We prospectively evaluated whether abnormalities at the lumbar level as diagnosed by magnetic resonance imaging (MRI) are confirmed by epiduroscopy, and assessed if targeted epidural injection of medication alleviates sciatic pain. METHODS: A flexible, 0.9-mm fiberoptic endoscope was introduced through a disposable steering shaft into the caudal epidural space and advanced until the targeted spinal nerve was identified. Adhesions were mechanically mobilized under direct vision, and a mixture of 120 mg methylprednisolone acetate, 600 IU hyaluronidase, and 150 microg clonidine was applied locally. Pain scores were measured by visual analog scale (VAS) and global subjective efficacy rating. RESULTS: Nineteen of 20 patients studied showed adhesions via epiduroscopy. In 8 patients, 6 of whom had never undergone surgery, these were not detected with earlier magnetic resonance imaging. Six patients showed concomitant signs of active root inflammation. Of 20 patients treated with a targeted epidural injection, 11 patients (55%) experienced significant pain relief at 3 months. This was maintained at 6, 9, and 12 months for 8 (40%), 7 (35%), and 7 (35%) patients, respectively. Mean VAS at 3 months was significantly reduced (n = 20; DeltaVAS = 3.55; P <.0001), and this persisted at 12 months (DeltaVAS = 1.99, P =.0073). CONCLUSIONS: Epiduroscopy is of value in the diagnosis of spinal root pathology. In sciatica, adhesions unreported by MRI can be identified. Targeted epidural medication, administered near the compromised spinal nerve, results in substantial and prolonged pain relief.