Large-scale real-world data on a multidisciplinary approach to spinal cord stimulation for persistent spinal pain syndromes: first evaluation of the Neuro-Pain® nationwide screening and follow-up interactive register.

Introduction: Spinal cord stimulation is a common treatment option for neuropathic pain conditions. Despite its extensive use and multiple technological evolutions, long term efficacy of spinal cord stimulation is debated. Most studies on spinal cord stimulation include a rather limited number of patients and/or follow-ups over a limited period. Therefore, there is an urgent need for real-world, long-term data. Methods: In 2018, the Belgian government initiated a nationwide secure platform for the follow-up of all new and existing spinal cord stimulation therapies. This is a unique approach used worldwide. Four years after the start of centralized recording, the first global extraction of data was performed. Results: Herein, we present the findings, detailing the different steps in the centralized procedure, as well as the observed patient and treatment characteristics. Furthermore, we identified dropouts during the screening process, the reasons behind discontinuation, and the evolution of key indicators during the trial period. In addition, we obtained the first insights into the evolution of the clinical impact of permanent implants on the overall functioning and quality of life of patients in the long-term. Discussion: Although these findings are the results of the first data extraction, some interesting conclusions can be drawn. The long-term outcomes of neuromodulation are complex and subject to many variables. Future data extraction will allow us to identify these confounding factors and the early predictors of success. In addition, we will propose further optimization of the current process.

Long-Term Outcome in Patients With Spinal Cord Stimulation for Failed Back Surgery Syndrome: A 20-Year Audit of a Single Center.

STUDY DESIGN: This is a retrospective, observational study. INTRODUCTION: Spinal cord stimulation (SCS) has found its application in chronic pain treatment, with failed back surgery syndrome (FBSS) as one of the most important indications. However, to date, little is known about the long-term effectiveness of the treatment. The aim of this study is to analyze retrospectively the long-term outcomes of SCS treatment in a single multidisciplinary pain center on predominant radicular pain, using devices of a single manufacturer. MATERIALS AND METHODS: Patient data on overall patient satisfaction, pain intensity, and adverse events were retrospectively collected in our clinical practice between January 1998 and January 2018, for 191 patients who received a permanent SCS implant. Secondary health measures included the influence of opioid and nicotine use on pain reduction after therapy. RESULTS: The trial-to-implant ratio was 93.6%. At a mean follow-up of 10.6 years, 78.5% of the patients were satisfied with the treatment outcome, with a significant pain reduction of an average three points on a Numeric Rating Scale. Opioid and nicotine usage did not have a significant link with the pain reduction one year after the treatment. Furthermore, devices had an average battery lifespan of 8.4 years. A total of 248 revisions were recorded. A total of 24 patients (11.7%) acquired an infection; 7 of 204 patients had an infection during the trial period, 2 of 191 patients had an infection in the first postoperative year, and 15 of 191 patients had an infection after the first year. The average time to infection, if not in the first year, was 10.1 years. CONCLUSIONS: A successful long-term outcome regarding pain relief in patients with predominant radicular pain due to FBSS is established with SCS therapy.

Does the presence of cranial contrast spread during a sacroiliac joint injection predict short-term outcome?

BACKGROUND: The innervation of the sacroiliac joint (SIJ) is complex, with a dual innervation originating from the lumbosacral plexus anteriorly as well as the sacral lateral branches posteriorly. Nociceptors are found in intra-articular structures as well as periarticular structures. In patients with SIJ pain, a fluoroscopy-guided SIJ injection is usually performed posteriorly into the bottom one-third of the joint with local anesthetic and corticosteroids, but this does not always reach all intra-articular structures. The correlation between a cranial contrast spread and clinical success is undetermined in patients with SIJ pain. METHODS: In a tertiary referral pain center, electronic medical records of patients who underwent an SIJ injection were retrospectively analyzed. Only patients with at least three positive provocation maneuvers for SIJ pain were selected. Contrast images of the SIJ were classified as with or without cranial spread on fluoroscopy as a marker of intra-articular injection. Clinical success was defined as ≥50% improvement in the patient's global perceived effect after 3-4 weeks. The primary outcome was defined as the correlation between cranial contrast spread and clinical success after an SIJ injection. RESULTS: 128 patients in total were included. In 68 patients (53.1%) fluoroscopy showed cranial contrast spread. Clinical success was higher in patients with cranial spread of contrast (55 of 68, 81%) versus those without (35 of 60, 58%) (p=0.0067). In a multivariable analysis with age, gender, presence of rheumatoid arthritis, side, and number of positive provocation maneuvers, the cranial spread of contrast remained the only independent factor of clinical success (p=0.006; OR 3.2, 95% CI 1.4 to 7.7). CONCLUSION: In patients with SIJ pain, identified by positive pain provocation maneuvers, cranial contrast spread as a marker of intra-articular injection, with subsequent injection of 3 mL of local anesthetic and methylprednisolone 40 mg, was significantly correlated with clinical success up to 4 weeks. Therefore, attempts should be made to reach this final needle position before injecting local anesthetic and corticosteroids. This result needs to be confirmed in a high-quality prospective trial.

Does the Use of Epiduroscopic Lysis of Adhesions Reduce the Need for Spinal Cord Stimulation in Failed Back Surgery Syndrome? A Short-Term Pilot Study.

BACKGROUND AND AIMS: Persistent low back pain after initially successful surgery that is not attributed to structural deficits is called failed back surgery syndrome (FBSS). When conservative and minimal invasive therapy fail, the recommended treatment is spinal cord stimulation (SCS). Because epidural fibrosis can be a contributing factor in the majority of FBSS patients, lumbosacral epiduroscopic lysis of adhesions may be considered as a less invasive alternative treatment option. We hypothesized that the use of epiduroscopic lysis of adhesions could reduce the need for SCS. METHODS: A pilot study was performed in 35 consecutive patients with FBSS who underwent epiduroscopic lysis of adhesions. SCS was considered if epiduroscopic lysis of adhesions gave less than 50% global perceived effect (GPE) improvement after 15 months of follow-up. The GPE was measured 1 week and 6 months after the procedure. RESULTS: Over a period of 69 months, 35 patients were included. After 15 months of follow-up, 43% of patients required SCS. Eight of the 15 patients who reported no short-term improvement needed SCS; those patients had severe epidural fibrosis. One week after epiduroscopic lysis of adhesions, 34%, 23%, and 43% of patients reported GPE improvement of > 50%, 20% to 50%, and < 20%, respectively. After 6 months, 5 patients were lost to follow-up, and 30%, 17%, and 16% of patients reported improvement of > 50%, 20% to 50%, and < 20%, respectively. CONCLUSIONS: In this pilot study we observed a reduced need for SCS when lumbosacral epiduroscopic lysis of adhesions was used for patients with FBSS and magnetic resonance imaging-proven adhesions. These observations justify the evaluation of both treatment options in a prospective observational trial.

High-Density in Spinal Cord stimulation: Virtual Expert Registry (DISCOVER): Study Protocol for a Prospective Observational Trial.

BACKGROUND: Spinal cord stimulation (SCS) is a proven and effective treatment for neuropathic pain conditions such as failed back surgery syndrome (FBSS). The hypothesis that different settings for SCS parameters activate unique, pain-relieving mechanisms has boosted the development of various SCS paradigms. High density spinal cord stimulation (HD-SCS) is one of those promising, novel stimulation forms characterized by subthreshold stimulation, delivering more pulses per second and a higher pulse density to the spinal cord than conventional SCS. OBJECTIVES: The aim of DISCOVER is to gather evidence about the effectiveness, feasibility, and (possible) side effects of HD stimulation. METHODS: The prospective, non-interventional, multi-center, clinical study, DISCOVER, is currently restricted to Belgium where 19 neuromodulation centers were selected. Patient recruitment started in October 2016 and is expected to end in October 2017. Subjects included are (1) patients with insufficient pain relief from conventional SCS or (2) neurostimulation-naïve patients suited for SCS. Patients will be assessed 1 month, 3 months, and 12 months after conversion to HD-SCS settings. Each patient's visit will include: a numerical rating scale (NRS), Oswestry disability index (ODI), Pittsburgh sleep quality index (PSQI), EQ-5D, a pain map, registration of SCS settings, and a list of used pain medication. CONCLUSIONS: Although promising results have been reported, adequate registration of its effectiveness and (possible) side-effects remains an unmet need. Main results are expected in 2019.

Effect of minocycline on lumbar radicular neuropathic pain: a randomized, placebo-controlled, double-blind clinical trial with amitriptyline as a comparator.

BACKGROUND: Less than 50% of patients experience sufficient pain relief with current drug therapy for neuropathic pain. Minocycline shows promising results in rodent models of neuropathic pain but was not studied in humans with regard to the treatment of neuropathic pain. METHODS: In this randomized, double-blind, placebo-controlled clinical trial, patients with subacute lumbar radicular pain received placebo, amitriptyline 25 mg, or minocycline 100 mg once a day (n = 20 per group) for 14 days. Primary outcome measure was the pain intensity in the leg as measured by a numeric rating scale ranging from 0 to 10 on days 7 and 14. Secondary outcome measures were the reduction of neuropathic pain symptoms in the leg as determined with a neuropathic pain questionnaire, consumption of rescue medication, and adverse events on days 7 and 14. RESULTS: Sixty patients were randomized and included in an intention-to-treat analysis. After 14 days, patients in the minocycline and amitriptyline groups reported a reduction of 1.47 (95% confidence interval, 0.16-2.83; P = 0.035) and 1.41 (95% confidence interval, 0.05-2.78; P = 0.043), respectively, in the numeric rating scale compared to the placebo group. No differences were seen in the neuropathic pain questionnaire values at any time point during treatment between the three groups. The rate of adverse events in the amitriptyline group was 10% versus none in the minocycline and placebo groups. No differences were noted in the consumption of rescue medication. CONCLUSIONS: Although both groups differed from placebo, their effect size was small and therefore not likely to be clinically meaningful.

Intrathecal drug administration in chronic pain syndromes.

Chronic pain may recur after initial response to strong opioids in both patients with cancer and patients without cancer or therapy may be complicated by intolerable side effects. When minimally invasive interventional pain management techniques also fail to provide satisfactory pain relief, continuous intrathecal analgesic administration may be considered. Only 3 products have been officially approved for long-term intrathecal administration: morphine, baclofen, and ziconotide. The efficacy of intrathecal ziconotide for the management of patients with severe chronic refractory noncancer pain was illustrated in 3 placebo-controlled trials. A randomized study showed this treatment option to be effective over a short follow-up period for patients with pain due to cancer or AIDS. The efficacy of intrathecal opioid administration for the management of chronic noncancer pain is mainly derived from prospective and retrospective noncontrolled trials. The effect of intrathecal morphine administration in patients with pain due to cancer was compared with oral or transdermal treatment in a randomized controlled trial, which found better pain control and fewer side effects with intrathecal opioids. Other evidence is derived from cohort studies. Side effects of chronic intrathecal therapy may either be technical (catheter or pump malfunction) or biological (infection). The most troublesome complication is, however, the possibility of granuloma formation at the catheter tip that may induce neurological damage. Given limited studies, the evidence for intrathecal drug administration in patients suffering from cancer-related pain is more compelling than that of chronic noncancer pain.

Percutaneous radiofrequency ablation of the splanchnic nerves in patients with chronic pancreatitis: results of single and repeated procedures in 11 patients.

BACKGROUND: Pain is a major problem for chronic pancreatitis (CP) patients. Unfortunately, medical therapy often fails. Endoscopic and surgical treatments are invasive, and results vary. Percutaneous radiofrequency ablation of the splanchnic nerves (RFSN) is a relatively new and minimally invasive procedure for treatment of intractable pain in CP patients. MATERIALS AND METHODS: We retrospectively evaluated 18 RFSN procedures in 11 CP patients, all refractory to analgesics. Five patients underwent a second procedure; two patients underwent a third procedure. NRS pain scores were assessed. Complications, analgesics usage, and length of the pain-free period were recorded. RESULTS: Radiofrequency ablation of the splanchnic nerves was effective in 15/18 interventions. The mean NRS pain score decreased from 7.7 ± 1.0 to 2.8 ± 2.7 (P ≤ 0.001). The pain-free period lasted for a median period of 45 weeks. The effect of repeated interventions was comparable to the initial procedure. One transient side effect was reported. Four patients reported significantly reduced analgesic usage; 4 patients completely stopped their pain medication. CONCLUSION: Radiofrequency ablation of the splanchnic nerves is a minimally invasive, effective procedure for pain relief. After the effect has subsided, RFSN can be successfully repeated. RFSN might become an alternative treatment in a selected group of CP patients. A larger, randomized trial is justified to substantiate these findings.

Establishing the diagnosis of low back pain: patient selection for interventional pain medicine.

SUMMARY Low back pain is one of the most prominent healthcare problems but there is no gold standard for its diagnosis. Aspecific low back pain can be subdivided into radicular and mechanical pain. The diagnosis mainly relies on a combination of elements, such as medical history, physical examination, medical imaging and other possible additional tests. Once a working diagnosis has been established, confirmation of the causative structure and level is sought by means of diagnostic blocks. The use of the different diagnostic tests and blocks should be guided by the balance between the potential benefit (mainly in terms of improved treatment outcome, the possible burden for the patient and the chances of withholding potential effective treatment to patients) with false-negative test results.

26. Pain in chronic pancreatitis.

Chronic pancreatitis is defined as a progressive inflammatory response of the pancreas that has lead to irreversible morphological changes of the parenchyma (fibrosis, loss of acini and islets of Langerhans, and formation of pancreatic stones) as well as of the pancreatic duct (stenosis and pancreatic stones). Pain is one of the most important symptoms of chronic pancreatitis. The pathogenesis of this pain can only partly be explained and it is therefore often difficult to treat this symptom. The management of pain induced by chronic pancreatitis starts with lifestyle changes and analgesics. For the pharmacological management, the three-step ladder of the World Health Organization extended with the use of co-analgesics is followed. Interventional pain management may consist of radiofrequency treatment of the nervi splanchnici, spinal cord stimulation, endoscopic stenting or stone extraction possibly in combination with lithotripsy, and surgery. To date, there are no randomized controlled trials supporting the efficacy of radiofrequency and spinal cord stimulation. The large published series reports justify a recommendation to consider these treatment options. Radiofrequency treatment, being less invasive than spinal cord stimulation, could be tested prior to considering spinal cord stimulation. There are several other treatment possibilities such as endoscopic or surgical treatment, pancreatic enzyme supplementation and administration of octreotide and antioxidants. All may have a role in the management of pain induced by chronic pancreatitis.

Pulsed radiofrequency for the treatment of occipital neuralgia: a prospective study with 6 months of follow-up.

BACKGROUND AND OBJECTIVES: Occipital neuralgia is a paroxysmal nonthrobbing, stabbing pain in the area of the greater or lesser occipital nerve caused by irritation of these nerves. Although several therapies have been reported, no criterion standard has emerged. This study reports on the results of a prospective trial with 6 months of follow-up in which pulsed radiofrequency treatment of the greater and/or lesser occipital nerve was used to treat this neuralgia. METHODS: Patients presenting with clinical findings suggestive of occipital neuralgia and a positive test block of the occipital nerves with 2 mL of local anesthetic underwent a pulsed radiofrequency procedure of the culprit nerves. Mean scores for pain, quality of life, and medication intake were measured 1, 2, and 6 months after the procedure. Pain was measured by the visual analog and Likert scales, quality of life was measured by a modified brief pain questionnaire, and medication intake was measured by a Medication Quantification Scale. RESULTS: During a 29-month period, 19 patients were included in the study. Mean visual analog scale and median Medication Quantification Scale scores declined by 3.6 units (P = 0.002) and 8 units (P = 0.006), respectively, during 6 months. Approximately 52.6% of patients reported a score of 6 (pain improved substantially) or higher on the Likert scale after 6 months. No complications were reported. CONCLUSIONS: Pulsed radiofrequency treatment of the greater and/or lesser occipital nerve is a promising treatment of occipital neuralgia. This study warrants further placebo-controlled trials.