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.     

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.     

Evaluation of a Dual Quadripolar Surgically Implanted Spinal Cord Stimulation Lead for Failed Back Surgery Patients with Chronic Low Back and Leg Pain

Objectives. Recent publications on dual program spinal cord stimulation (SCS) system demonstrate more flexible electrode programming, which helps to steer paresthesias towards all of the affected areas including the low back area. Materials and Methods. The following data were retrospectively sought from 20 nonrandomized failed back surgery patients at two centers treated by a dual quadripolar surgically implanted SCS lead: pain and paresthesia, VAS ratings, medication use, sleep patterns, daily activities, hardware problems, and willingness to repeat the procedure. The data were analyzed by the Wilcoxon signed rank test (p value < 0.05). Results. The average paresthesia coverage was 76%. After SCS implantation, analgesic use was decreased in 59% of the patients, sleeping time augmented, and quality of sleep improved. The number of patients taking benzodiazepines decreased. Sixty percent reported increased participation in social activities. Conclusions. This dual program surgical SCS technique is simple, respects patients’ autonomy, and provides adequate analgesia with an increase in quality of life.     

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.     

Evolving Patterns of Spinal Cord Stimulation in Patients Implanted for Intractable Low Back and Leg Pain

The objective of this study was to examine the programming strategies used in patients with intractable low‐back pain treated with epidural spinal cord stimulation (SCS) utilizing paddle electrodes and a radio frequency (RF) stimulator. Programming strategies were examined in a group of patients implanted with a 16‐contact paddle electrode and a dual channel RF receiver to treat chronic low‐back pain. Baseline data included previous surgical history information, leg and low back pain severity and characteristics, and routine demographic information. Outcome measurements included the visual analog scale (VAS) 1 , patient pain relief rating scale, and programming parameters. Patients rated their pain relief on a 5‐point scale where 4 = excellent, 3 = good, 2 = fair, 1 = poor and 0 = none. Success was determined to be a pain relief score of “fair” or above. Data were collected during patient visits or by mail, at approximately 6, 12, and 24 months, postoperatively. Immediate postop data were available in 16 patients, 6‐month data in 21 patients, 1‐year data in 20 patients, and 2‐year data in 10 patients, and analyzed for the purposes of examining programming strategies. The most common location for the tip of the electrode (lead) was found to be in the middle of the 8th thoracic vertebrae (N = 26). At the immediate postop assessment, the majority of cathodes were activated in the upper half of T9. By the 6‐month follow‐up, the majority of cathodes had shifted to the bottom of T9 and top of T10. Overall 88% of cathode locations were changed at one or more study visits. At 2 years, 86% of the programs used four or more active contacts. At 6 months, 83% of the patients reported that the therapy was a success, at 1 year, success was 94%, and by 2 years, success was 75%. Both SCS and chronic pain are dynamic processes. Complex pain patterns, such as the ones of patients who have pain in the low back and in one or both lower extremities, require a high degree of flexibility in the implanted SCS system. The system must provide the capability to redirect the current electronically over at least two segments of the spinal canal, to electronically steer the current in a medio‐lateral direction, and to activate multiple electrical contacts simultaneously. The willingness and ability to provide extensive reprogramming in the long term follow‐up is also of the utmost importance. Pain and its treatment with SCS is a dynamic process.     

Early Experience With a Novel Miniaturized Spinal Cord Stimulation System for the Management of Chronic Intractable Pain of the Back and Legs

IntroductionA novel, spinal cord stimulation (SCS) system with a battery-free miniaturized implantable pulse generator (IPG) was used in this feasibility study. The system uses an external power source that communicates bidirectionally with the IPG (< 1.5 cm³). Human factors, subject comfort, and effects on low back and leg pain were evaluated in this first-in-human study.Materials and MethodsA prospective, multicenter, open-label clinical trial was initiated to evaluate the safety and performance of a novel miniaturized stimulator in the treatment of chronic, intractable leg and low-back pain. Eligible subjects were recruited for the study and gave consent. Subjects who passed the screening/trial phase (defined as ≥ 50% decrease in pain) continued to the long-term implant phase and were followed up at predefined time points after device activation. Interim clinical and usability outcomes were captured and reported at 90 days.ResultsResults of 22 subjects who chose a novel pulsed stimulation pattern therapy using the battery-free IPG (< 1.5 cm³) are described here. At 90-days follow-up, the average pain reduction was 79% in the leg (n = 22; p < 0.0001) and 76% in the low back (n = 21; p < 0.0001) compared with baseline. Responder rates (≥ 50% pain relief) at 90 days were 86% in leg pain (19/22) and 81% in low-back pain (17/21). Subjects rated the level of comfort of the external wearable power source to be 0.41 ± 0.73 at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable).DiscussionThese interim results from the ongoing study indicate the favorable efficacy and usability of a novel, externally powered, battery-free SCS IPG (< 1.5 cm³) for leg and low-back pain. Study subjects wore the external power source continuously and found it comfortable, and the system provided significant pain relief. These preliminary findings warrant further investigation.Clinical Trial RegistrationThe Clinicaltrials.gov registration number for the study is ACTRN12618001862235.     

Treatment of Failed Back Surgery Syndrome Patients with Low Back and Leg Pain: A Pilot Study of a New Dual Lead Spinal Cord Stimulation System

Objective. Treatment of pain associated with failed back surgery syndrome was evaluated in a pilot clinical study of a new dual lead spinal cord stimulation (SCS) system. Methods. The following data was retrospectively sought from 20 non-randomized patients at 2 centers treated by the new SCS system, instead of an implantable drug pump: 1) prior back surgeries, 2) pain and paresthesia mapping, 3) VAS ratings, 4) medication use, 5) sleep patterns, 6) physical abilities, 7) hardware problems, and 8) willingness to repeat the procedure. Two-year follow-up was sought from all patients. Results. The new dual lead SCS system provided good low back and leg paresthesia coverage. Patients reported having less pain and using fewer analgesics and narcotics during follow-up, compared to their preimplant experience. These improvements were statistically significant. Patients also improved their sleep and physical abilities during follow-up. While external hardware problems occurred, 65% of dual lead SCS patients were willing to repeat the SCS implant procedure. Conclusions. Dual lead stimulation proved beneficial for patients with low back and leg pain associated with failed back surgery syndrome.     

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.     

Spinal Cord Stimulation to Treat Low Back Pain in Patients With and Without Previous Spine Surgery

ObjectivesLittle is known about the effects of spinal cord stimulation (SCS) on chronic low back pain (CLBP) patients with no history of previous spine surgery. Using our prospectively collected database, we evaluate improvements in patients with and without previous spine surgery one-year post SCS implantation.Materials and MethodsSubjects completed outcome metrics pre-operatively and one-year post-implantation including Numeric Rating Scale (NRS), McGill Pain Questionnaire (MPQ), Oswestry Disability Index (ODI), Beck’s Depression Inventory (BDI), and Pain Catastrophizing Scale (PCS).ResultsWe enrolled 134 patients; 82 patients had previous spine surgery and 52 patients did not. At one-year post-SCS implantation, patients with previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, MPQ affective, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.03, p = 0.01, p = 0.02, p < 0.001, p = 0.05, p < 0.001, p = 0.017, respectively). Likewise, patients without previous spine surgery showed improvements in worst pain experienced, least pain experienced, average pain experienced, pain felt currently, MPQ, MPQ sensory, PCS, PCS helplessness, PCS rumination, PCS magnification, ODI, and BDI scores (p < 0.001, p = 0.005, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p < 0.001, p = 0.008, p < 0.001, p < 0.001, respectively). Patients without previous spine surgery showed greater improvements for average pain PCS helplessness (p = 0.01).ConclusionsPatients with and without previous spine surgery showed similar improvements in pain intensity, pain quality, feelings of rumination and magnification, functional disability, and depression severity. SCS can improve CLBP regardless of whether patients have had previous spine surgery.     

1.2 kHz High-Frequency Stimulation as a Rescue Therapy in Patients With Chronic Pain Refractory to Conventional Spinal Cord Stimulation

ObjectivesWe aimed to investigate the efficacy of new subperception stimulation paradigms including 1.2 kHz-high-frequency stimulation (HFS) and advanced-HFS field-shaping algorithm (dorsal horn HFS [DHHFS]) in refractory cases which initially benefited from conventional spinal cord stimulation (SCS) and lost the effect throughout time.Materials and MethodsIn the context of a rescue-therapy, patients underwent externalization of the implanted SCS-leads and were tested with multiple combinations of new SCS paradigms. Pain intensity was analyzed using the numeric rating scale (NRS), and data were collected preoperatively and at multiple postoperative follow-ups.ResultsThirty-seven patients underwent externalization of the leads. Mean preoperative NRS-score was 8.1/10 points (SD ± 0.9) for the ON-stimulation period. Patients received a combination of either tonic, burst and 1.2 kHz-HFS, or burst and 1.2 kHz-HFS, DHHFS, or 1.2 kHz-HFS and DHHFS, or 1.2 kHz-HFS alone. The mean postoperative NRS-score after the testing-phase was 3.8/10 points (SD ± 2.5), showing a 48.0% mean reduction (p < 0.001). In total, 29 patients reported a significant reduction above 50% in NRS-scores and therefore were reimplanted with new generators that could deliver the new paradigms. Eight patients underwent full SCS-system explantation. The patients who continued with the new paradigms (n = 29) reported mean NRS-scores of 3.5/10 points (SD ± 1.7) 12 months postoperatively, still showing a significant reduction of 43.3% when compared to preoperative scores (p < 0.001).ConclusionRescue-therapy with combination of multiple waveforms, including tonic, burst, 1.2 kHz-HFS, and DHHFS, was associated with a significant pain relief in patients with failed conventional SCS. This approach is a safe and efficient and should be considered before explantation of the SCS-system.     

Computer Assisted and Patient Interactive Programming of Dual Octrode Spinal Cord Stimulation in the Treatment of Chronic Pain

Objective. To evaluate the effectiveness of spinal cord stimulation using multiple independent programmable electrode selections compared to simple continuous stimulation. Design. Prospective case series 2 years. Setting. Ambulatory care center. Patients. All chronic pain patients who underwent spinal cord stimulation treatment at our center from February 1995 until October 1996 entered the study as a consecutive sample (n = 80). Interventions. Patients were evaluated in continuous stimulation mode (single stimulation program) vs. multi-stimulation mode, (patients activate a series of stimulation programs simultaneously to cover all of their pain) and patient-controlled stimulation mode (patients can select a program in response to their activities and pain level). Outcome measures. We collected visual analog pain scores, patient satisfaction scores by stimulation mode, and paresthesia maps. Results. Mean pain scores declined from 8.1 at baseline to 4.6 with continuous stimulation, and to 3.1 with multi-stimulation and with patient-controlled stimulation (p<0.05). Paresthesia overlap improved from 74% with continuous stimulation to 91% with multi-stimulation, and to 89% with patient-controlled stimulation (p<0.05). None of the patients selected continuous stimulation. Thirty-two patients preferred multi-stimulation, and 48 patients preferred patient-controlled stimulation. Lead revision rates declined from 15% in our previous experience using continuous stimulation to 3.8%. Conclusions. Continuous stimulation was not selected by any patient in favor of multi-stimulation or patient-controlled stimulation. This study indicates that in spinal cord stimulation the use of multiple electrodes together with advanced programmability increases paresthesia overlap, reduces pain scores, reduces revision rates, and improves patient satisfaction with spinal cord stimulation therapy.