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.     

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.     

Treatment of Multifocal Pain with Spinal Cord Stimulation

Introduction: We report a retrospective case study of combined treatment of cancer‐related pain and chronic low back and lower extremity pain related to postlaminectomy syndrome (PLS) with one spinal cord stimulation (SCS) system. Methods: The patient underwent an uneventful SCS trial with percutaneous placement of two temporary eight‐electrode leads (Medtronic Inc., Minneapolis, MN) placed at the level of T8‐T9‐T10 and T5‐T6‐T7. Results: After successful trial, he was implanted with permanent leads and generator, reporting sustained pain relief at 12‐month follow‐up visit. Discussion: SCS is a trialable, reversible, and interactive therapy permitting patients to control the level of stimulation they feel based on their degree of pain. Conclusion: SCS provides an effective, alternative treatment for select patients with cancer‐related chest wall pain and pain related to PLS who have failed conservative treatment.     

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.     

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.     

Treatment of Chronic Chest Wall Pain in a Patient With Loeys-Dietz Syndrome Using Spinal Cord Stimulation

Objective: Spinal cord stimulation (SCS) has been used with increased frequency for the treatment of intractable pain including chronic chest pain. Methods: The patient with a history of Loeys‐Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain underwent an uneventful SCS trial with percutaneous epidural placement of two temporary eight‐electrode leads placed at the level of T3‐T4‐T5. Results: After experiencing excellent pain relief over the next two days, the patient was implanted with permanent leads and rechargeable generator four weeks later and reported sustained pain relief at 12‐month follow‐up visit. Conclusion: SCS provides an effective, alternative treatment option for select patients with Loeys‐Dietz syndrome who underwent repair of pectus excavatum with subsequent chronic chest wall pain who have failed conservative treatment. SCS may provide pain relief with advantages over conservative treatments and more invasive techniques.     

Spinal Cord Stimulation for Visceral Pain From Chronic Pancreatitis

Background and Objectives: Spinal cord stimulation (SCS) may reduce pain scores and improve function in patients with various chronic abdominal pain syndromes including chronic pancreatitis. Here described is a large clinical experience in SCS for severe chronic pancreatitis. Methods: SCS was trialed in 30 patients with chronic pancreatitis. SCS trials lasted 7–14 days (median 9 days). SCS lead tips were mostly positioned at the T5 (N= 10) or T6 (N= 10) vertebral level. Results: Twenty‐four patients (80%) reported at least 50% pain relief on completion of the trial. Among these, pre‐trial visual analog scale (VAS) pain scores averaged 8 ± 1.6 (standard deviation) and opioid use averaged 165 ± 120 mg morphine sulfate equivalents. During the trial, VAS pain scores decreased to 3.67 ± 2 cm (p < 0.001, Mann–Whitney Rank Sum Test) and opioid use decreased to 105 ± 101 mg morphine equivalent a day. Six patients failed the trial; one was lost to follow‐up; in three patients after the implantation, the system had to be removed due to infection or lead migration; and 20 were followed for the whole year. For 20 patients followed for the whole year, VAS pain scores remained low (3.6 ± 2 cm; p < 0.001) at one year, as did opioid use (48.6 ± 58 mg morphine equivalents). Conclusions: SCS may be a useful therapeutic option for patients with severe visceral pain from chronic pancreatitis. Prospective trial is warranted.     

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.     

Peripheral Nerve Stimulation: A Percutaneous Minimally Invasive Approach

We report on the use of a new percutaneous technique for peripheral nerve stimulation (PNS) treatment of chronic pain. A 56‐year‐old woman was diagnosed with algodystrophic syndrome, now called Complex Regional Pain Syndrome, type 2 (CRPS2), due to a lesion of the right medial nerve despite surgical revascularization, angioplasty and stent insertion. After a successful 10‐day trial of PNS via a percutaneous quadripolar lead in the interscaline space, an implantable pulse generator was implanted in the abdominal subcutaneous tissue and connected to the subcutaneous lead via an extension. After one year of follow‐up, the patient was still experiencing good pain relief. We conclude that this novel percutaneous PNS technique offers the advantage of being a minimally invasive approach that can be easily adopted for the management of chronic pain.     

Spinal Cord Stimulation for Intractable Pain Following Limb Amputation

Objective: Spinal cord stimulation (SCS) by high‐frequency electrical pulses has been used since the early 1970s for relief of chronic intractable pain following limb amputation. The long‐term effectiveness of SCS for amputation‐related pain with ongoing after‐care is reviewed by assessment of all such cases managed over 20 years in the Neurostimulator Clinic at the Royal London Hospital. Materials and Methods: Twelve amputation‐related pain patients had quadripolar paddle electrodes (Resume; Medtronic Inc., Minneapolis, MN, USA) inserted epidurally by laminectomy over the thoracic or cervical dorsal spinal cord and connected to remotely controlled subcutaneously implanted stimulators (Itrel2, Itrel3, Synergy; Medtronic). Results: Two of 12 patients had unsuccessful stimulation, one despite repeated electrode revisions. Two were subsequently lost to follow‐up, one had delayed spontaneous resolution of phantom limb pain, one had a technical fault, and one had gradually waning benefit over 19 years. In the remaining five patients having ongoing follow‐up, self‐reported initial and final magnitudes of pain relief were unchanged, with a mean (SD) of 66% (18.2%). Benefits calculated from local and general visual analogue pain scores were similarly unchanged (initial local 48.8% [18.7%]; final local 50.0% [17.6%]; initial general 60.8% [10.9%]; final general 57.9% [12.3%]). Continued successful stimulation often required frequent changes of stimulating electrode contacts. Revision procedures for technical problems or pain at the battery site were universally successful. Conclusions: Successful SCS in some patients with amputation‐related pain otherwise resistant to treatment indicates that the procedure merits continued use with further efforts to refine technique.     

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.     

A Case Report of Subcutaneous Peripheral Nerve Stimulation for the Treatment of Axial Back Pain Associated With Postlaminectomy Syndrome

Objective. This article aims to present a case of the use of an alternative form of neuromodulation for the treatment of axial back pain associated with postlaminectomy syndrome. Materials and Methods. An elderly patient with long‐standing axial back pain in the setting of a prior decompressive laminectomy presented for evaluation and treatment. After failing to obtain significant benefit from more conservative measures, a trial of peripheral nerve stimulation (PNS) was performed. Results. The patient reported > 75% relief of his pain during the seven‐day trial period, and accordingly a permanent PNS system was implanted. The permanent system consisted of four Medtronic Quad Plus leads, two on each side of midline oriented horizontally over the L4–5 paraspinous muscles. Our patient was ultimately weaned off of all narcotic medications and, at one year follow‐up, continues to report > 90% reduction of pain.     

Spinal Cord Stimulation for the Treatment of Chronic Pain in Patients with Lumbar Spinal Stenosis

Objective: Chronic back and leg pain associated with lumbar spinal stenosis (LSS) is common in the elderly. Surgical decompression is usually performed when conservative treatments fail. We present an evaluation of the long‐term outcome of patients suffering from symptomatic LSS treated with spinal cord stimulation (SCS). Materials and Methods: Data were collected prospectively in three independent registries in three European centers. Pooled data were analyzed retrospectively. Changes in pain intensity, functional status, and analgesic medication were compared at baseline and at the last available follow‐up. Demographic data as well as details regarding the implantation procedure and any adverse events were systematically recorded. Results: Data were recorded in 69 patients with a mean follow‐up period of 27 months. All patients showed clinically and statistically significant improvement in pain relief, the visual analog scale decreasing from 7.4 ± 2.3 to 2.8 ± 2.4 (p < 0.05). The use of analgesic medication decreased and the functional status improved. Conclusion: Spinal cord stimulation seems to be effective in the treatment of patients suffering from chronic pain associated with LSS. Being less invasive and reversible, SCS should be considered before surgical decompression, particularly in patients with increased risks associated with back surgery.     

Spinal Cord Stimulation and Thalamic Pain: Long‐term Results of Eight Cases

Objectives. We submit a retrospective analysis of results of eight patients suffering from intractable pain of established or suspected thalamic origin. These patients were treated with spinal cord stimulation (SCS) in the cervical or dorsal cord. No patient was suffering pain from a complete hemibody or facial area. Material and Methods. Five men and three women aged 27–67 years were treated in the Pain Unit of our institution between April 1993 and January 2006. The cause of pain in five cases was stroke (plus one suspected). Multiple sclerosis was responsible for pain in two cases. An upper or lower extremity was affected in six cases. Extension to adjacent trunk was common. Exclusive trunk pain was treated in two cases. Results. The follow‐up period was 36–149 months. Two patients were not battery‐implanted because pain relief was insufficient during the trial phase. Two patients had a further stroke: One died and one was cured from pain. Good‐to‐excellent results were attained in six patients; long‐term good‐to‐excellent results were maintained in three patients. Conclusions. Despite previous adverse reports, certain cases of thalamic pain can be effectively alleviated through SCS.     

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.     

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.     

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.     

A New Spinal Cord Stimulation System Effectively Relieves Chronic,Intractable Pain: A Multicenter Prospective Clinical Study

Objectives. A prospective, open label, multicenter clinical trial confirmed the functionality of a new spinal cord stimulation (SCS) system for the treatment of chronic, intractable pain of the trunk and/or limbs. Materials and Methods. Sixty‐five subjects tested a rechargeable 16‐channel SCS system with individual current control of each contact on one or two percutaneous eight‐contact epidural leads. After baseline measurements, subjects were tracked on pain ratings and complication rates for up to 18 months. Results. After a trial period, 75% of subjects underwent permanent implantation of the entire SCS system. More than one‐half the implanted subjects experienced 50% or greater relief of pain after permanent implantation; some subjects reported relief of 90% or more of their pain. The most common complications after permanent implantation were lead migration, uncomfortable stimulation, and component failure; most resolved after reprogramming or device replacement. Conclusions. The new SCS system provided good pain relief to a majority of subjects, and the results confirm a favorable safety and efficacy profile for the SCS system.     

A Prospective,Randomized Single-Blind Crossover Study Comparing High-Frequency 10,000 Hz and Burst Spinal Cord Stimulation

ObjectivesAlthough both high-frequency and burst spinal cord stimulation (SCS) have shown improved efficacy and patient satisfaction compared with conventional tonic stimulation, there are limited data directly comparing the two. This study aimed to compare both high-frequency 10,000 Hz and burst SCS in the same patients in terms of pain relief and satisfaction in those with axial back pain with or without leg pain.Materials and MethodsThis prospective, single-blind, randomized controlled trial was conducted at an outpatient pain clinic within an academic medical center. Participants were randomly allocated to one of two groups in which they trialed either burst or high-frequency 10,000 Hz SCS over five days, followed by a 24- to 48-hour washout period with no stimulation, and the alternative therapy over the remaining four days. Visual analog scale (VAS) scores were collected immediately before and after both therapy trials. Secondary end points included percentage change in VAS score and patient preference.ResultsOf 25 participants, those receiving burst followed by high-frequency SCS (n = 11) had a mean VAS difference of 4.73 after the first trial period and 2.86 after the second. Of those receiving high-frequency followed by burst SCS (n = 14), mean VAS difference after the first trial period was 4.00 and 1.93 after the second trial period. Four participants were withdrawn owing to lead migration. Both therapies showed statistically significant differences in pre- minus post-VAS scores and percent relief. There were no significant differences in carryover or treatment effects between the two groups. There was a statistically significant association between trial sequence and stimulator type implanted because the first stimulator trialed was more likely to be chosen.ConclusionsThere were no observed differences in VAS pain score decrease when comparing burst and high-frequency 10,000 Hz SCS programming therapies. Patient preference followed an order effect, favoring the first programming therapy in the trial sequence.