Epidural Spinal Cord Stimulation with a Multiple Electrode Paddle Lead Is Effective in Treating Intractable Low Back Pain

The objective of this paper is to examine the outcomes of patients with intractable low‐back pain treated with epidural spinal cord stimulation (SCS) utilizing paddle electrodes and a radio frequency (RF) stimulator. A multicenter prospective study was performed to collect data from patients suffering from chronic low‐back pain. The study was designed to collect data from 60 patients at four centers and examine their outcomes at, or up to two years post implantation. Patients' participation included written responses to a series of preoperative questionnaires that were designed to collect previous surgical history information, leg and low back pain characteristics, and routine demographic information. Outcome measurements included the visual analog scale (VAS), the Oswestry Disability Questionnaire, the Sickness Impact Profile (SIP), and a patient satisfaction rating scale. Data were collected at each site during patient visits or by mail, at approximately six months, 12 months, and 24 months. A total of 44 patients have been implanted with a SCS system at the time of this writing. Follow‐up data were available for 41 patients. Preoperatively, all patients reported more than 50% of their pain in the low back. All patients had pain in both their backs and legs. All patients showed a reported mean decrease in their 10‐point VAS scores compared to baseline. The majority of patients reported fair to excellent pain relief in both the low back and legs. At six months 91.6% of the patients reported fair to excellent relief in the legs and 82.7% of the patients reported fair to excellent relief in the low back. At one year 88.2% of the patients reported fair to excellent relief in the legs and 68.8% of the patients reported fair to excellent relief in the low back. Significant improvement in function and quality of life was found at both the six‐month and one‐year follow‐ups using the Oswestry and SIP, respectively. The majority of patients reported that the procedure was worthwhile (92% at six months, 88% at one year). No patient indicated that the procedure was not worthwhile. We conclude that SCS proved beneficial at one year for the treatment of patients with chronic low back and leg pain.     

Spinal Cord Stimulation With Hybrid Lead Relieves Pain in Low Back and Legs

Objective: The failed back surgery syndrome (FBSS) is the most common chronic pain syndrome. Whereas it is relatively easy to achieve pain relief in the lower limbs of FBSS patients with spinal cord stimulation (SCS), it is difficult to manage low back pain with SCS. The performance of a paddle‐shaped SCS lead that can be inserted surgically as well as percutaneously (a hybrid lead) was evaluated in a prospective study on the relief of low back pain and leg pain in patients with FBSS. Materials and Methods: Patients with FBSS being eligible for SCS were enrolled in the study, and a hybrid lead was placed surgically. Outcome measures included pain scores for low back and leg pain assessed by visual analog scale (VAS), pain medication, and patient satisfaction. These scores were assessed before and at regular intervals after implantation. Results: It was shown that a single hybrid lead, generally positioned over the physiological midline of the spinal cord, is capable of alleviating both low back and leg pain in patients with FBSS. Forty‐five subjects were eligible for SCS and received trial stimulation. Forty‐two of them had a successful trial period and were converted to a permanent system. Their average VAS score at baseline was 8.0 for lower limb pain and 7.5 for low back pain. After six months of SCS, these average VAS scores were reduced to 3.2 and 3.5, respectively, and also pain medication was reduced significantly. Conclusion: SCS with a hybrid lead in subjects with FBSS is safe, and causes significant pain relief in both the low back and the lower limbs.     

Long-Term Outcomes of Spinal Cord Stimulation With Paddle Leads in the Treatment of Complex Regional Pain Syndrome and Failed Back Surgery Syndrome

Introduction: Spinal cord stimulation (SCS) is frequently used to treat chronic, intractable back, and leg pain. Implantation can be accomplished with percutaneous leads or paddle leads. Although there is an extensive literature on SCS, the long‐term efficacy, particularly with paddle leads, remains poorly defined. Outcome measure choice is important when defining therapeutic efficacy for chronic pain. Numerical rating scales such as the NRS‐11 remain the most common outcome measure in the literature, although they may not accurately correlate with quality of life improvements and overall satisfaction. Methods: We reviewed the medical records of patients with failed back surgery syndrome (FBSS) or complex regional pain syndrome (CRPS) implanted with SCS systems using paddle leads between 1997 and 2008 at the Cleveland Clinic with a minimum six‐month follow‐up. Patients were contacted to fill out a questionnaire evaluating outcomes with the NRS‐11 as well as overall satisfaction. Results: A total of 35 eligible patients chose to participate. More than 50% of the patients with CRPS reported greater than 50% pain relief at a mean follow‐up of 4.4 years. Approximately 30% of the FBSS patients reported a 50% or greater improvement at a mean follow‐up of 3.8 years. However, 77.8% of patients with CRPS and 70.6% of patients with FBSS indicated that they would undergo SCS surgery again for the same outcome. Conclusion: Patients with CRPS and FBSS have a high degree of satisfaction, indexed as willingness to undergo the same procedure again for the same outcome at a mean follow‐up of approximately four years. The percentage of satisfaction with the SCS system is disproportionally greater than the percentage of patients reporting 50% pain relief, particularly among patients with FBSS. This suggests that the visual analog scale may not be the optimal measure to evaluate long‐term outcomes in this patient population.     

Percutaneous Implanted Paddle Lead for Spinal Cord Stimulation: Technical Considerations and Long‐Term Follow‐Up

Objectives: Spinal cord stimulation (SCS) is an established method for treatment of chronic pain. Cylindrical‐type leads can be implanted percutaneously. In contrast, paddle leads (lamitrode) require more invasive surgery (i.e., laminotomy or laminectomy) for placement into the epidural space, thereby offering several advantages over percutaneous leads (octrode), including less lead migration and better paresthesia coverage. The goal of this study was to prospectively demonstrate the safety and efficacy of a percutaneous paddle lead for SCS. Materials and Methods: This prospective trial enrolled 81 patients. The mean age was 57 years (range 27–82 years) with an almost equal sex distribution (male 47%, female 53%). Most patients (90%) had failed back surgery syndrome combined with lower extremity pain and lower back pain. A percutaneous paddle lead was implanted using a novel introduction system for percutaneous implantation. All implantations were performed under local anesthesia. Prior to the final implantation of the impulse generator, all patients underwent seven days of trial stimulation with pain assessment using a visual analog scale (VAS). The median follow‐up was 12 months. Results: The data showed favorable clinical outcomes for paresthesia coverage and pain reduction (median VAS 8.4 vs. 2.3), with a risk profile comparable with known percutaneous techniques. Compared with the published data (2–22%), the lead migration rate in this study was low (2.5%). No perioperative complications occurred. Conclusions: This new, minimally invasive percutaneous paddle lead is effective and safe, with a low migration rate. Placement can be done under local anesthesia, allowing an intraoperative assessment of the paresthesia coverage in terms of pain relief. This approach is less invasive and offers a faster and more comfortable procedure compared with laminotomy or laminectomy.     

Spinal Cord Stimulation Versus Re-operation in Patients With Failed Back Surgery Syndrome: An International Multicenter Randomized Controlled Trial (EVIDENCE Study)

Objective: This paper presents the protocol of the EVIDENCE study, a multicenter multinational randomized controlled trial to assess the effectiveness and cost‐effectiveness of spinal cord stimulation (SCS) with rechargeable pulse generator versus re‐operation through 36‐month follow‐up in patients with failed back surgery syndrome. Study Design: Study subjects have neuropathic radicular leg pain exceeding or equaling any low back pain and meet specified entry criteria. One‐to‐one randomization is stratified by site and by one or more prior lumbosacral operations. The sample size of 132 subjects may be adjusted to between 100 and 200 subjects using a standard adaptive design statistical method with pre‐defined rules. Crossover treatment is possible. Co‐primary endpoints are proportion of subjects reporting ≥50% leg pain relief without crossover at 6 and at 24 months after SCS screening trial or re‐operation. Insufficient pain relief constitutes failure of randomized treatment, as does crossover. Secondary endpoints include cost‐effectiveness; relief of leg, back, and overall pain; change in disability and quality of life; and rate of crossover. We are collecting data on subject global impression of change, patient satisfaction with treatment, employment status, pain/paresthesia overlap, SCS programming, and adverse events. Discussion: As the first multicenter randomized controlled trial of SCS versus re‐operation and the first to use only rechargeable SCS pulse generators, the EVIDENCE study will provide up‐to‐date evidence on the treatment of failed back surgery syndrome.     

Electrophysiologic Monitoring for Placement of Laminectomy Leads for Spinal Cord Stimulation Under General Anesthesia

Objectives: Spinal cord stimulation (SCS) is a valid option for intractable neuropathic pain syndromes, yet some patients cannot undergo the standard awake procedure. Our retrospective study chronicles laminectomy‐electrode placement for SCS under general anesthesia and use of compound muscle action potentials (CMAPs) to guide placement in the absence of patient verbal feedback. Methods: After nonsurgical measures proved ineffective for relief of neuropathic pain, 8 men and 11 women underwent SCS lead placement under general rather than local anesthesia because of deafness, language barriers, lidocaine allergy, or extensive scar tissue. A midline thoracic laminectomy was performed, and paddle SCS leads were placed. CMAPs of the rectus abdominis, quadriceps, gastrocnemius, anterior tibialis, abductor hallicus, and intercostal muscles were analyzed. Final lead placement was determined by the right‐to‐left symmetry of the CMAPs in conjunction with fluoroscopic imaging. Stimulation coverage was evaluated postoperatively. Results: Inconsistencies were found in lower‐extremity CMAPs in the first two procedures. Thereafter, intercostal and rectus abdominis muscle CMAPs obtained in the remaining 17 procedures were consistent, more predictive of final results. Immediately postoperatively, 16 (84.2%) of 19 patients had adequate stimulation coverage and good pain relief with appropriate programming. Of three (15.8%) patients with minimal or no short‐term pain relief, lack of response was not attributable to inadequate distribution of stimulation. Conclusions: With electrophysiologic monitoring and fluoroscopy guidance, placement of SCS laminectomy leads in select patients under general anesthesia may result in appropriate stimulation coverage and pain relief in most.     

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.     

Acute vs. Prolonged Screening for Spinal Cord Stimulation in Chronic Pain

Spinal cord stimulation (SCS) was performed to test the hypothesis that pain relief data during acute (15 minute intraoperative) and prolonged (5 day) SCS screening have equivalent predictive value for long‐term successful SCS control of chronic low back pain and/or lower extremity pain. A retrospective series of patients with chronic low back and/or lower extremity pain underwent either percutaneous or open (ie, laminectomy) SCS implantation during which acute intraoperative followed by prolonged screening trials for percentage pain relief (%PR) were performed. Data were analyzed for (a) correlation between positive predictive value (PPV) of acute and prolonged SCS screening for %PR and (b) PPV of acute vs. prolonged screening %PR for long‐term SCS %PR. Fifty‐four patients (male/female = 38/16; mean age ± SEM = 54.2 ± 2.0 years) underwent thoracic (T) (mean level = T9.1 ± 0.4) percutaneous (n = 33) and laminectomy (n = 21) implantation of SCS for acute (15 minute intraoperative) and prolonged (5.0 ± 0.3 days) SCS screening of pain relief. Correlation between successful (> 50%PR) pain relief during acute (n = 53/54, PPV = 98%) and prolonged (n = 47/52, PPV = 90%) screening was significant (Spearman Rank Correlation Coefficient, SRCC = 0.462, p < 0.01). After permanent SCS implantation, at mean follow‐up = 9.4 ± 1.5 months, acute and prolonged SCS screening %PR PPV's were each statistically significant for predicting long‐term SCS relief of chronic pain (n = 31/38, PPV = 82% and n = 31/36, PPV = 86%, SRCC = 0.462 and 0.433, respectively, p < 0.01). We conclude that successful pain relief during acute SCS screening is highly correlated with successful prolonged SCS screening of chronic low back and/or lower extremity pain relief. Acute and prolonged SCS screening appear to have equivalent predictive value for successful long‐term SCS control of chronic low back and/or lower extremity pain. These preliminary results suggest potential justification for eliminating prolonged and retaining acute (intraoperative) SCS screening for selection of permanent SCS implantation candidates.     

A Unique Approach to Neurostimulation in Patients With Previous Two‐Segment Spine Surgery and Obstruction of Epidural Access for Spinal Cord Stimulation: A Case Series

Introduction: Patients with extensive surgery in the lumbar and thoracic spine are often not considered for neurostimulation due to the inability to perform a conventional spinal cord stimulation (SCS) trial. We are presenting six such patients in which spinal‐peripheral neurostimulation (SPN) was used via a caudal approach. Methods: Six patients with intractable low back and leg pain following extensive lumbar and thoracic surgeries, up to at least the T10 level, underwent a stimulation trial with one caudal lead and one subcutaneous lead in order to achieve SPN. Results: In five cases, the trial was successful with coverage of the pain area and at least satisfactory pain relief. All six patients were implanted with a paddle lead(s) and a subcutaneous lead using SPN with good pain control. Conclusion: SPN with a caudal lead appears to be a viable option for SCS trial in patients with no possibilities for conventional trial lead placement.     

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 for Failed Back Surgery Syndrome

Objective. The purpose of this study is to evaluate the effectiveness of modern spinal cord stimulation (SCS) for the treatment of failed back surgery syndrome (FBSS). Materials and Methods. Thirty patients were treated with SCS between December 1992 and January 1998 for low back and radicular pain after multiple failed back surgeries. Permanent systems were implanted if trial stimulation led to > 50% pain reduction. Median long‐term follow‐up was 34 months (range, 6–66 months). Severity of pain was determined postoperatively by a disinterested third party. Results. Overall, 12 of the 16 patients (75%) who received permanent implants continued to report at least 50% relief of pain at follow‐up. All six patients who underwent placement of laminectomy‐styled electrode for SCS in the thoracic region had > 50% pain relief at long‐term follow‐up. Visual analog scores decreased an average of 3.2 (from 8.6 preoperatively to 5.4 postoperatively). Patients undergoing SCS placement via laminectomy in the thoracic region experienced an average decrease of 4.9 in VAS, whereas those who underwent percutaneous placement of thoracic leads had an average decrease of 2.5. Conclusions. SCS is an effective treatment for chronic low back and lower extremity pain which is refractory to conservative therapy and which is not amenable to corrective anatomic surgery. Though our patient population is small, our results imply that the laminectomy‐style electrodes in the thoracic region achieve better long‐term effectiveness than percutaneous leads.     

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.     

Lumbar Spinal Cord Stimulation Can Improve Muscle Strength and Gait Independently of the Analgesic Effect: A Case Report

Spinal cord stimulation (SCS) is widely used for pain relief in patients with failed back surgery syndrome (FBSS), and muscle weakness is a common finding in patients with chronic pain. We present here a single case report of a 47‐year‐old woman, who, after SCS for FBSS, had continuous improvement in lower leg muscle strength and gait, but only transient and minimal pain relief. To the authors’ knowledge, this is only the second published case report of significant improvement in “motor” function, independent of the analgesic effect following SCS in FBSS. If SCS, in fact, does improve muscle strength, new strategies for the management of patients with chronic pain might be opened up. Further studies are needed to verify this hypothesis.     

Subcutaneous Peripheral Nerve Stimulation with Inter‐lead Stimulation for Axial Neck and Low Back Pain: Case Series and Review of the Literature

Objectives: While pain in the extremities often responds to treatment using spinal cord stimulation (SCS), axial pain is notoriously refractory to SCS. Interest in subcutaneous peripheral nerve stimulation (SQ PNS) as an alternative to SCS has emerged, but the most appropriate electrode locations and neurostimulator programming techniques are not yet clear. Methods: A retrospective review was conducted of consecutive patients evaluated from August 2009 to December 2010 who had undergone trial of SQ PNS with inter‐lead stimulation for axial spine pain. Patients proceeding to implant were followed postoperatively with routine clinical visits and a survey form at last follow‐up. Ultrasound was used intraoperatively to ensure placement of electrodes at the appropriate depth in patients with larger body mass index. Primary outcome was patient‐reported pain relief at last follow‐up. Literature review was conducted by searching MEDLINE (1948–present) and through an unstructured review by the authors. Results: Ten patients underwent trial of SQ PNS and six proceeded to permanent implantation. Fifty percent (3/6) of implanted patients preferred neurostimulation programming that included inter‐lead stimulation (“cross‐talk”). Average duration of postoperative follow‐up was 4.5 months (range 2–9 months). Average patient‐reported pain relief at last follow‐up was 45% (range 20–80%). One patient required re‐operation for migration. Patients not proceeding to implant had paresthesia coverage but no analgesia. Conclusion: SQ PNS is a promising therapy for axial neck and back pain based on a small cohort of patients. Ultrasound was useful to assist with electrode placement at the most appropriate depth beneath the skin. While inter‐lead stimulation has been preferred by patients in published reports, we did not find it clearly influenced pain relief. Future investigations should include a randomized, controlled study design, as well as defined implantation technique and neurostimulator programming algorithms.     

Subcutaneous Stimulation as an Additional Therapy to Spinal Cord Stimulation for the Treatment of Lower Limb Pain and/or Back Pain: A Feasibility Study

Objective: The objective of this study was to demonstrate the efficacy of subcutaneous stimulation (SubQ) as an additional therapy in patients with failed back surgery syndrome (FBSS) with chronic refractory pain, for whom spinal cord stimulation (SCS) was unsuccessful in treating low back pain. Study Design: Case series. Materials and Methods: FBSS patients with chronic limb and/or low back pain whose conventional therapies had failed received a combination of SCS (8‐contact Octad lead) and/or SubQ (4‐contact Quad Plus lead(s)). Initially leads were placed in the epidural space for SCS for a trial stimulation to assess response to suppression of limb and low back pain. Where SCS alone was insufficient in treating lower back pain, leads were placed superficially in the subcutaneous tissue of the lower back, directly in the middle of the pain area. A pulse generator was implanted if patients reported more than 50% pain relief during the trial period. Pain intensity for limb and lower back pain was scored separately, using visual analog scale (VAS). Pain and Quebec Back Pain Disability Scale (QBPDS) after 12‐month treatment were compared with pain and QBPDS at baseline. Results: Eleven FBSS patients, five male and six female (age: 51 ± 8 years; mean ± SD), in whom SCS alone was insufficient in treating lower back pain, were included. In nine cases, SubQ was used in combination with SCS to treat chronic lower back and lower extremity pain. In two cases only SubQ was used to treat lower back pain. SCS significantly reduced limb pain after 12 months (VAS_bl: 62 ± 14 vs. VAS_12m: 20 ± 11; p= 0.001, N= 8). SubQ stimulation significantly reduced low back pain after 12 months (VAS_bl: 62 ± 13.0 vs. VAS_12m: 32 ± 16; p= 0.0002, N= 10). Overall pain medication was reduced by more than 70%. QBPDS improved from 61 ± 15 to 49 ± 12 (p= 0.046, N= 10). Furthermore, we observed that two patients returned to work. Conclusion: SubQ may be an effective additional treatment for chronic low back pain in patients with FBSS for whom SCS alone is insufficient in alleviating their pain symptoms.     

Psychological Variables Associated With Outcome of Spinal Cord Stimulation Trials

Study Design. This is a prospective study designed to identify psychological factors associated with response to spinal cord stimulation (SCS) trial. Summary of Background Data. In most centers, implantation of a permanent SCS system is preceded by a trial of a temporary stimulating electrode. Yet, even among those who report greater than 50% pain reduction during trial, a significant number of these patients fail to receive long-term pain relief from the permanent system. Because mood disorders can alter pain report, we hypothesized that refined definition of the psychological factors associated with SCS success could result in improved selection of candidates for SCS trial. Methods. The study sample consisted of 43 chronic pain patients (72% failed back surgery syndrome, 77% with radiating low back pain) who were referred for implantable pain management. Following psychological evaluation, patients were admitted for a three-day inpatient trial of SCS. Report of at least 50% pain relief during trial was considered a success and resulted in implantation of the permanent stimulator. Patients were retrospectively divided into two groups: those whose pretrial pain was relieved by at least 50% (“success”) and those whose pain was relieved by less than 50% (“failure”). Results. Univariate t-test or chi-square analyzes of group means of an extensive psychological battery followed by a global, stepwise logistic regression model of trial outcome was used to analyze between group results of a psychological test battery. MMPI depression and mania subscores were found to be significantly elevated among the two outcome groups (p = 0.007 and 0.025, respectively). Conclusions. Patient mood state is an important predictor of trial outcome. Specific indicators of SCS trial outcome are the MMPI depression and mania subscale scores with successful trials being associated with individuals who are less depressed and have higher energy levels.     

Surgical Paddle Electrode Implantation as a Rescue Therapy to Failed Percutaneous Leads in Failed Back Surgery Syndrome Patients

IntroductionSpinal cord stimulation (SCS) to treat failed back surgery syndrome (FBSS) can be provided with either percutaneously or surgically implanted electrodes. Percutaneous electrodes are considered the first choice in many pain practices, but surgical paddle electrodes can also be indicated if a percutaneous electrode fails to retain sufficient pain relief or if percutaneous implantation is considered unachievable. Although the current efficacy of surgical paddle electrodes has been based mainly upon pain intensity scores, the evidence on surgical paddle electrodes as a rescue to failed percutaneous electrodes remains even more scarce.ObjectiveThis study aimed to evaluate the safety and clinical effectiveness of rescue surgical paddle electrodes in FBSS patients, multidimensionally.Materials and MethodsThe occurrence of complications, pain intensity scores, psychosocial-related questionnaires, and medication intake were collected. Subsequently, a Quality-of-Life Index (QLI) was calculated. A clinically relevant effect was obtained if the minimal clinically important difference regarding pain intensity was reached.ResultsA total of 25 patients were included in the study. The pain intensity scores were significantly reduced (p < 0.001), and clinically relevant reductions occurred during short-term (0–6 months), mid-term (1–3 years), and long-term follow-up (≥4 years). The structural morphine usage and QLI were significantly decreased at short-term follow-up (p = 0.038 and p = 0.036, respectively). Six complications occurred in five patients, of which, four concerned hardware-related problems and two were of biological origin.ConclusionSCS utilizing a surgical paddle electrode as a salvage treatment to failed conventional percutaneous cylindrical lead SCS can be practiced safely and effectively to treat FBSS. Because of potentially improved clinical effectiveness and cost-effectiveness resulting from fewer reoperations, a SCS treatment algorithm may benefit from expediting surgical paddle electrodes.     

Spinal Cord Stimulation Has Comparable Efficacy in Common Pain Etiologies

Objectives. The probability of success with spinal cord stimulation (SCS) depends largely on appropriate patient selection. Here, we have assessed the predictive value of pain etiology as it relates to pain relief with SCS as part of a prospective multicenter clinical trial. Methods. Sixty‐five subjects with chronic and intractable pain tested an epidural SCS system. Subjects reported pain ratings (visual analog scale) with stimulation off and stimulation on at scheduled follow‐up visits for up to 18 months after activation of the system. Visual analog scale scores were averaged and stratified by dominant pain etiologies, comprising failed back surgery syndrome, complex regional pain syndrome, and a subgroup of subjects with miscellaneous other pain etiologies. Results. More than 70% of subjects in each subgroup had successful outcomes during the temporary trial period and similar percentages of subjects from each etiology subgroup subsequently went on to permanent implantation. After permanent implantation, all subgroups reported more than 50% pain relief, on average, at each follow‐up time point. No predictive value of pain etiology was observed. Conclusions. Spinal cord stimulation is an effective therapy for neuropathic pain arising from a variety of causes. Failed back surgery syndrome, complex regional pain syndrome, and pain of other etiologies responded equally well to SCS.     

Successful Long‐Term Outcomes of Spinal Cord Stimulation Despite Limited Pain Relief During Temporary Trialing

Objectives. In spinal cord stimulation (SCS) therapy, limited pain relief during the temporary trial period is generally considered to be predictive of poor long‐term benefit. To validate or refute this perception, the long‐term outcomes of subjects who reported less than 50% pain relief during a temporary SCS trial were examined. Materials and Methods. Twelve subjects with intractable pain underwent implantation of trial SCS systems. After a trial period in which they reported less than 50% pain relief, they each received a permanent SCS implant. Pain ratings and complications were tracked for 6–18 months. Results. At the end of the temporary trial period, the average pain relief was 21%; no subject reported 50% or better pain relief. More favorable outcomes were reported after activation of the permanent system, however. At all follow‐up time points, at least a third of the subjects reported better than 50% pain relief, and the average pain relief varied over time between 44% and 83%. All complications were readily resolved and no subjects withdrew from the study. Conclusions. Although SCS provided limited pain relief during the trial period, efficacy was more satisfactory after permanent implantation. Several subjects went on to experience nearly complete pain relief for up to 18 months (the maximum follow‐up visit for study purposes), and no subject chose to discontinue SCS therapy. SCS appears to be a viable treatment option for patients who fail trials, raising some doubt as to the predictive sensitivity and specificity of the trial period. Thus, although outcome of a temporary trial period may be suggestive of later efficacy with SCS, it may not be the sole predictor of success. Alternatively, the arbitrary benchmark of 50% pain relief that is typically used to define the success of a temporary trial may be too stringent and unreliable.     

Spinal Cord Stimulation: A 20‐Year Retrospective Analysis in 260 Patients

Introduction. Spinal cord stimulation (SCS) is used clinically by many pain physicians and neurosurgeons alike without regard to their own outcome data. Methods. We reviewed our 20‐year experience retrospectively of patients receiving SCS implants and analyzed our data by pain type and group. Results. We present 260 patients, 140 men and 120 women. The most frequent type of pain in our series was neuropathic pain in 44.25% and the most frequent diagnosis was peripheral vascular disease (PVD) with 98 cases. The second was failed back surgery syndrome (FBSS) with 65 cases and the third was complex regional pain syndrome type I (CRPS I), with 40 cases. In CRPS group, the mean visual analog scale (VAS) of this group was 77.89 ± 13.38. In total, 5% had no pain relief, 40% had poor pain relief, 47.5% had good pain relief, and 7.5% had excellent pain relief. In FBSS group, the mean VAS was 79.62 ± 11.69 mm. A total of 13.80% had no pain relief at all, 35.39% had poor pain relief, 50.76% had good pain relief, and there were no patients in this group who had complete pain relief. A total of 98 patients, 78 men and 20 women, were diagnosed with PVD. The mean VAS of this group was 69.75 ± 14.36 mm. A total of 11.22% had poor pain relief, 87.75% had good pain relief. One patient had complete pain relief and all patients in this group perceived at least some improvement in their symptoms. The rate of complications was close to 28% in our overall sample. Conclusions. In conclusion, we demonstrated the utility over time of this type of treatment is comparable with other series of efficacy of SCS. The analgesic efficacy was close to 65% in the overall group. The therapy was not free of complications. The preponderance of our patients was patients with the diagnosis of PVD and our results in this group of patients were excellent. These excellent results of more than 90% improvement suggest to us that SCS be considered as a first‐line approach to the clinical management of patients with pain and ulcer of PVD.