Spinal Cord Stimulation for Post‐Herniorrhaphy Pain

Objective. Post‐herniorrhaphy pain syndrome can be difficult to treat. The exact mechanism of pain is not always apparent. Multiple therapeutic modalities have been suggested for the treatment of this syndrome. Method. This includes both conservative (medical management), surgical (scar revision, excision of neuroma), and/or interventional approaches (local blocks to the entrapped nerves or sympathetic ganglion). Results. Two cases of intractable post–herniorrhaphy pain syndrome which failed to respond to conservative therapy are reviewed. Both cases had a successful trial therapy with spinal cord stimulation for their pain. Both then had permanent implantable systems inserted with favorable outcomes. Conclusion. Post‐herniorrhaphy pain can have the same features of both nociceptive and neuropathic pain syndromes. In cases which have failed conservative therapy we believe that a trial of spinal cord stimulation is warranted as in other cases of neuropathic pain syndromes.     

Spinal Cord Stimulation as Alternative Treatment for Chronic Post‐Herniorrhaphy Pain

Objective: Our goal was to determine the efficacy of spinal cord stimulation for patients with intractable post‐herniorrhaphy pain which conventional treatment failed to ameliorate. Procedure: The patients underwent an uneventful spinal cord stimulator (SCS) trial with percutaneous placement of two eight‐electrode epidural leads (Medtronic Inc, Minneapolis, MN, USA) to level T7‐T8‐T9. Results: Upon experiencing excellent pain relief over the next two days during the trial, the patients were implanted with permanent leads and rechargeable or non‐rechargeable generators two to four weeks later and reported sustained pain relief during following 12 months after implantation. Conclusion: We conclude that SCS offers an alternative treatment option for intractable post‐herniorrhaphy pain. This type of treatment should be considered for use in a select group of patients when all conventional treatments failed.     

Spinal Cord Stimulation With Additional Peripheral Nerve/Field Stimulation Versus Spinal Cord Stimulation Alone on Back Pain and Quality of Life in Patients With Persistent Spinal Pain Syndrome

IntroductionPersistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS) refers to new or persistent pain following spinal surgery for back or leg pain in a subset of patients. Spinal cord stimulation (SCS) is a neuromodulation technique that can be considered in patients with predominant leg pain refractory to conservative treatment. Patients with predominant low back pain benefit less from SCS. Another neuromodulation technique for treatment of chronic low back pain is subcutaneous stimulation or peripheral nerve field stimulation (PNFS). We investigated the effect of SCS with additional PNFS on pain and quality of life of patients with PSPS compared with that of SCS alone after 12 months.Materials and MethodsThis is a comparative study of patients with PSPS who responded to treatment with either SCS + PNFS or SCS only following a multicenter randomized clinical trial protocol. In total, 75 patients completed the 12-month follow-up: 21 in the SCS-only group and 54 in the SCS + PNFS group. Outcome measures were pain (visual analog scale), quality of life (36-Item Short Form Survey [SF-36]), anxiety and depression (Hospital Anxiety and Depression Scale [HADS]), overall health (EuroQol Five-Dimension [EQ-5D]), disability (Oswestry Disability Index [ODI]), and pain assessed by the McGill questionnaire.ResultsThere were no significant differences in baseline characteristics between the two groups. Both groups showed a significant reduction in back and leg pain at 12 months compared with baseline measurements. No significant differences were found between the groups in effect on both primary (pain) and secondary parameters (SF-36, HADS, EQ-5D, ODI, and McGill pain).ConclusionIn a subgroup of patients with chronic back and leg pain, SCS alone provided similar long-term pain relief and quality-of-life improvement as PNFS in addition to SCS. In patients with refractory low back pain not responding to SCS alone, adding PNFS should be recommended.Clinical Trial RegistrationThe Clinicaltrials.gov registration number for the study is NCT01776749.     

Efficacy of Peripheral Nerve Field Stimulation for the Management of Chronic Low Back Pain and Persistent Spinal Pain Syndrome: A Narrative Review

ObjectivesVarious approaches have been developed with a view to treating the back pain component in patients with chronic low back pain (CLBP) and persistent spinal pain syndrome (PSPS). Emerging evidence shows that peripheral nerve field stimulation (PNFS) may be an efficacious therapeutic modality against axial low back pain. Hence, the aim of the review was to evaluate the analgesic efficacy and safety of PNFS, when used alone or as an adjunct to spinal cord stimulation (SCS), for managing CLBP and PSPS.Materials and MethodsA comprehensive search for clinical studies on PNFS and PNFS + SCS used for the management of CLBP and/or PSPS was performed using PubMed, EMBASE, MEDLINE via Proquest, and Web of Science.ResultsA total of 15 studies were included, of which four were randomized controlled trials (RCTs), nine were observational studies, and two were case series. For patients receiving PNFS, a significant decrease in back pain intensity and analgesic consumption, together with a significant improvement in physical functioning, was observed upon implant of the permanent system. Meanwhile, the addition of PNFS to SCS in refractory cases was associated with a significant reduction in back and leg pain, respectively.ConclusionsThis review suggests that PNFS, when used alone or in combination with SCS, appears to be effective in managing back pain. However, high-quality evidence that supports the long-term analgesic efficacy and safety is still lacking. Hence, RCTs with a larger patient population and of a longer follow-up duration are warranted.     

An Innovative Case Report Detailing the Successful Treatment of Post‐Thoracotomy Syndrome with Peripheral Nerve Field Stimulation

Introduction: The detrimental effects of post‐thoracotomy pain syndrome is experienced worldwide; however, an effective treatment regimen remains elusive. Methods: We report a case of post‐thoracotomy pain syndrome effectively treated with peripheral nerve field stimulation (PNfS). Results: In the presented case, the patient underwent permanent placement of the PSfS device after a successful trial period. Upon follow‐up the patient has reported even better coverage over her painful areas and admits to 80% and higher reductions in her painful symptoms. Conclusion: Although the data are limited, in the aforesaid case report, post‐thoracotomy syndrome was effectively treated with the use of PNfS. This resulted in a significant pain perception reduction, increased quality of life and mobility, as well as decreased usage of oral pain medications. This adds to the accumulating case report and case series data that suggest PNfS is showing great promise as a pain reduction modality. Further, it is minimally invasive, can be trialled prior to implantation, and is reversible. Large prospective studies will be required in the future to further evaluate its efficacy before it can be widely accepted and adopted.     

Prospective,Two-part Study of the Interaction Between Spinal Cord Stimulation and Peripheral Nerve Field Stimulation in Patients with Low Back Pain: Development of a New Spinal-Peripheral Neurostimulation Method

Objective: The goal of the study was to assess the efficacy of interaction between spinal cord stimulation (SCS) and peripheral nerve field stimulation (PNFS) and to evaluate a new spinal‐peripheral neuromodulation method for low back pain. Materials and Methods: The prospective two‐part study included patients with low back pain due to failed back surgery syndrome and/or spinal stenosis. In the first part 20 patients were implanted with SCS and PNFS. They selected the best program out of three: SCS alone, PNFS alone, or both together. In the second part another 20 patients with the same implanted leads were selecting between three programs: SCS and PNFS separately, SCS as anode and PNFS as cathode, or in reverse. Results: In the first part 79% of the patients selected simultaneous use of SCS and PNFS. The overall success of the trials was 85%. In the second part communication between SCS and PNFS provided wider coverage of axial pain. The overall success of the trials was 90%. Conclusion: Simultaneous use of SCS and PNFS increase efficacy of both methods for axial back pain. The new SPN method showed great potential in providing coverage for back pain.     

Sacral Nerve and Spinal Cord Stimulation for Intractable Neuropathic Pain Caused by Spinal Cord Infarction

Central cord pain is very difficult to relieve, even with the many kinds of medical and surgical treatments available. Following spinal cord infarctions, central cord pain can develop. The problems that may arise could include limb pain, pelvic pain, difficulties voiding, and difficulties defecating. We are reporting a case of central cord pain caused by a spinal cord infarction of the conus medullaris. Limb pain was reduced by spinal cord stimulation. Voiding and defecation difficulties and pelvic pain were reduced by sacral nerve stimulation. Thus, in a case involving both intractable limb and pelvic pain, a combination therapy of these two stimulations might be an effective treatment modality.     

Spinal Cord Stimulation in Conjunction With Peripheral Nerve Field Stimulation for the Treatment of Low Back and Leg Pain: A Case Series

Background. The treatment of chronic low back and leg pain remains a difficult medical challenge, particularly for patients with postlaminectomy syndrome. While spinal cord stimulation (SCS) has been a significant addition to the available options, it is often inadequate in relieving both the back and leg pain components. We hypothesized that for some patients the combination of SCS with peripheral nerve field stimulation (PNFS) would be a safe, effective alternative that would be more effective than either modality alone. Objective. Our objective was to demonstrate the efficacy of PNFS used in combination with SCS for the treatment of chronic pain syndromes involving the lower back and legs. Study Design. Case series. Methods. A total of 20 patients with chronic low back and leg pain syndromes who had failed conventional therapies underwent implantation of a combination of traditional SCS and PNFS. Leads were placed in the epidural space, as well as superficially in the subcutaneous tissues of the lower back, directly in the region of maximum pain. Patients initially underwent a trial of stimulation to assess response, and a permanent system was implanted if patients reported greater than 50% pain relief during the trial. For some patients, a combination was used at the time of the initial trial. In other cases, the decision to proceed with the combination was made later, either at the time of permanent implant, or later on, after SCS alone failed to adequately control pain. Results. In each case, PNFS was used in combination with traditional SCS for patients with chronic lower back and lower extremity pain. While not all of these patients ultimately proceeded with the combination of SCS and PNFS to control their pain, the majority of patients found the combination better in controlling their overall pain than either modality alone. In addition, using a combined approach at the time of trial provided a noninvasive and effective method of comparing the efficacy of each method, allowing patients to identify the best form of neuromodulation for their particular pain. Conclusions. Due to the availability of 16 contact capacity generators, neurostimulation with multiple leads in various combinations—including both epidural and peripheral nerve field stimulation simultaneously—can be applied safely and effectively. The availability of this combined approach for a trial of stimulation prior to implant allows patients to compare SCS to PNFS and to indicate a preference for one over the other or for the combination. We conclude that PNFS may be used in combination with SCS as a safe and effective alternative treatment for patients with chronic low back and leg pain, and further suggest that the combined approach should be considered as a treatment option for this population.     

Triangular Stimulation Method Utilizing Combination Spinal Cord Stimulation With Peripheral Subcutaneous Field Stimulation for Chronic Pain Patients: A Retrospective Study

Objectives: This retrospective data collection study aims to evaluate the responses of patients who have been implanted with a neuromodulation system using a combination of spinal cord stimulation (SCS) and peripheral subcutaneous field stimulation (PSFS) leads for chronic intractable pain. Materials and Methods: Forty patients with chronic, intractable pain implanted with both SCS and PSFS leads were enrolled in a retrospective data collection study. Pre‐implant data (demographics, pain levels, pain location, and medication use) and post‐implant data (pain levels, medication use, and device programming reports) were compared to measure short‐ and long‐term improvements in pain for a period of approximately six months. Device system use and parameter data were collected. Results: The majority of patients experienced immediate and short‐term pain relief and reduction in oral pain medications as a result of combination SCS/PSFS therapy. The improvements were maintained for some, but not all patients by six months. Patients cycled through multiple programs over follow‐up; the use of triangular stimulation was consistent over time, and by six months, patients preferred this program over others. Limitations of the retrospective chart review included missing data and variable follow‐up times, and may have made determinations of long‐term efficacy difficult. Conclusions: This study demonstrates that combination SCS and PSFS therapy is potentially a beneficial treatment option for reducing pain levels and oral pain medication compared with baseline in previously resistive chronic pain patients. There is a need for further study of this therapy in a greater number of subjects and in a prospective, controlled setting. In the author's general experience, triangular stimulation is very effective for treating isolated low back pain, because it covers larger topographic areas of the lower back than flow or field stimulation. An investigational device exemption study will be necessary for subcutaneous field stimulation indicated for focal isolated pain to be adequately investigated and utilized by physicians in the future.     

Peripheral Nerve Field Stimulation in the Treatment of Postlaminectomy Syndrome after Multilevel Spinal Surgeries

Introduction: Chronic low back pain in patients with postlaminectomy syndrome (PLS) is challenging to treat, especially for patients who have undergone multilevel surgical procedures. Despite conservative therapy and available interventional pain procedures including spinal cord stimulation (SCS) and intrathecal therapies, patients may continue with intractable low back pain. Peripheral nerve field stimulation (PNFS) may represent an effective alternative treatment option for these patients when conventional treatments do not provide adequate relief of intractable low back pain. Methods: Eighteen patients underwent an uneventful PNFS trial with percutaneous placement of four temporary quadripolar leads (Medtronic, Inc., Minneapolis, MN, USA) placed subcutaneously over the lumbar or thoraco‐lumbar area. Results: After experiencing excellent pain relief over the next two days, temporary leads were removed. The patients were implanted with permanent leads and rechargeable or non‐rechargeable generator two to four weeks after temporary lead removal. All patients reported sustained pain relief 12 months after implantation. Discussion: PNFS with use of four vertically orientated leads provides an effective treatment option for patients with PLS after multilevel surgical procedures with intractable low back pain who have failed conservative treatment. PNFS may provide pain relief with advantages over conservative treatments and interventional treatments including SCS and intrathecal therapy. Conclusion: PNFS may be more effective in treating intractable low back pain than SCS in patients with PLS after multilevel spinal surgeries.     

Spinal Cord Stimulation (SCS) in Conjunction With Peripheral Nerve Field Stimulation (PNfS) for the Treatment of Complex Pain in Failed Back Surgery Syndrome (FBSS)

Background: Failed back surgery syndrome (FBSS) is a well‐defined pathologic condition observed over many years. Design: We have investigated the effect of spinal cord stimulation (SCS) with peripheral nerve field stimulation (PNfS) in eight patients with FBSS Outcome Measure: The following parameters were collected and analyzed: The pain intensity score on a 0–10 numbering rating scale (NRS), the psychologic profile with Beck Depression Inventory (BDI), the pain quality with McGill Pain Questionnaire—short form (MGPQ‐sf), the back pain with Oswestry scale score (OS), and the health general quality pattern with QualityMetric's SF‐36v2^® Health Survey. Patients: Eight patients with low back and radicular pain in FBSS are reported. The mean duration of pain was 6.7 months, and the mean NRS score was 9.5, BDI 28.8, MGPQ‐sf 16.8, OS 44.5, and SF‐36 score was 72.8. The average drug intake of opioids was 250 mg/day. Intervention: In six patients, two octopolar leads were placed in epidural space at D7‐D8 and D8‐D9, in conjunction with two octopolar leads placed in lumbar‐sacral subcutaneous space (Precision System, Boston Scientific, Valencia, CA, USA), and in two patients, a two tetrapolar leads was placed in epidural space at D8‐D9 with two tetrapolar leads (Pisces Quad, Plus, Medtronic Inc., Minneapolis, MN, USA) placed in lumbar‐sacral subcutaneous space (Restore Ultra, Medtronic Inc., Minneapolis, MN, USA). Results: After one year mean of follow‐up, the mean NRS score was 4, BDI 8, MGPQ‐sf 5, OS 21, and the SF‐36 score was increased at 108.5. The mean drug intake of opioids was decreased at 20 mg/day. Conclusion: The combination of SCS and PNfS, using the latest rechargeable systems, may be a valid therapeutic strategy in FBSS.     

Long-Term Outcome of Spinal Cord Stimulation for Chronic Pain Management

Study Design. This is a retrospective study on 102 patients subjected to implantation of a spinal cord stimulation system for nonmalignant chronic pain management. The study was conducted through an extensive questionnaire and telephone interviews by a neutral third party. All the patients were implanted with a complete spinal cord stimulation system without a preliminary trial with a temporarily implanted electrode. Diagnostic categories were neuropathic pain, failed back syndrome, spinal cord Injury pain, and miscellaneous. Average follow-up was 3.8 years (6 months to 8 years). Patients were divided in two groups: all the implanted patients in the survey (Group A) and the implanted patients who experienced some degree of pain relief with the stimulation (Group B). Group B (80 patients) closely matches previously published series where an initial temporary screening was performed. Results. Twenty-one percent of the patients never experienced any pain relief. Of the remaining 80, 75% were still using the stimulator. Fifty-one percent of the 80 patients were experiencing good to excellent results and 20% moderate results. There was no reduction over time in the amount of pain relief in patients who initially had at least 75% pain relief. Patients with initial pain relief between 50% and 74% observed a moderate reduction in their pain relief after two years. Patients who initially experienced less than 50% pain relief observed a dramatic reduction in their results in the long term follow-up. Psychological screening contributed to the success of the procedure. Conclusions. With proper medical and psychological screening and with demonstrated initial pain relief, spinal cord stimulation remains an effective modality in the long-term management of severe chronic pain.