High-Frequency Spinal Cord Stimulation at 10 kHz for the Treatment of Combined Neck and Arm Pain: Results From a Prospective Multicenter Study

Long-Term Efficacy and Safety of High-Frequency Spinal Stimulation for Chronic Pain: A Meta-Analysis of Randomized Controlled Trials

OBJECTIVE

The aim of our meta-analysis was to systematically assess the enduring effectiveness and safety of high-frequency spinal stimulation (HF-SCS) in the management of chronic pain.

METHODS

We developed a comprehensive literature search strategy to identify clinical trials investigating the efficacy of high-frequency spinal stimulation for chronic pain. The search was conducted in multiple databases, including Web of Science, Cochrane, PubMed, and Embase, covering the period from 2004 to 2023. The inclusion and exclusion criteria established for this study were applied to screen the eligible literature by carefully reviewing abstracts and, when necessary, examining the full text of selected articles. To assess the quality of the included studies, we utilized the Risk of Bias assessment tool provided by the Cochrane Collaboration. The PRISMA method was followed for the selection of articles, and the quality of the articles was evaluated using the risk assessment table for bias provided by the Cochrane Collaboration. Meta-analysis of the selected studies was performed using Review Manager 5.4 and STATA 16.0. Effect sizes for continuous data were reported as mean differences (MD) or standardized mean differences (SMD), while categorical data were analyzed using relative risks (RR).

RESULTS

According to our predefined literature screening criteria, a total of seven English-language randomized controlled trials (RCTs) were included in the meta-analysis. The findings from the meta-analysis demonstrated that HF-SCS exhibited superior efficacy in the long-term treatment of chronic pain when compared with the control group (RR=2.44, 95% CI: 1.20-4.96, P =0.01). Furthermore, HF-SCS demonstrated a statistically significant improvement in the Oswestry Disability Index score (mean difference MD=3.77, 95% CI: 1.17-6.38, P =0.005). However, for pain assessment (standardized mean difference SMD=-0.59, 95% CI: -1.28 to 0.10, P =0.09), Patient Global Impression of Improvement (PGI-I) score (MD=0.11, 95% CI: -0.66 to 0.88, P =0.78 for 6 months; MD=0.02, 95% CI: -0.42 to 0.43, P =0.97 for 12 mo), Clinical Global Impression of Improvement (CGI-I) score (MD=-0.58, 95% CI: -1.62 to 0.43, P =0.27 for 6 mo; MD=-0.23, 95% CI: -0.94 to 0.48, P =0.52 for 12 mo), and occurrence of adverse effects (odds ratio [OR]=0.77, 95% CI: 0.23-2.59, P =0.67), HF-SCS did not show statistically sufficient effects compared with the control group.

CONCLUSIONS

The findings from our comprehensive review and meta-analysis offer encouraging data about the prolonged efficacy and safety of HF-SCS in chronic pain management on some but not all outcomes. Recognizing the constraints of the existing evidence is crucial. Additional clinical trials, meticulously planned and stringent, are essential to bolster the current body of evidence and reach more conclusive findings.

Defining Short- and Long-Term Programming Requirements in Patients Treated With 10-kHz Spinal Cord Stimulation

OBJECTIVES

High-frequency spinal cord stimulation (10-kHz SCS) has been shown to be an effective treatment for refractory low back pain and neck pain with and without limb pain in clinical trial and real-world studies. However, limited information is available in the literature on the type and frequency of programming parameters required to optimize pain relief.

MATERIALS AND METHODS

Retrospective trial and postimplant clinical and system device data were analyzed from consecutive patients with neck pain and low back pain, with and without limb pain, from a single clinical site, including both thoracic and cervical lead placement. Best bipole, stimulation parameters, and outcomes, including pain relief, change in opioid medication use, sleep, and daily function, were analyzed.

RESULTS

Of the 92 patients in the trial, 70 received a permanent implant. Of these, the mean duration of follow-up was 1.8 ± 1.3 years. Pain relief of ≥50% at the last follow-up was achieved by 64% of patients implanted; in addition, 65% reduced their opioid medication use; 65% reported improved sleep, and 71% reported improved function. There was some consistency between the "best" bipole at trial and permanent implant, with 82% of patients within one bipole location, including 54% of permanent implants who were using the same best bipole as at trial. After permanent implant, device reprogramming was minimal, with ≤one reprogramming change per patient per quarter required to maintain pain outcomes.

CONCLUSIONS

In the study, 10-kHz SCS was an effective therapy for treating chronic pain, whereby a high responder rate (≥50% pain relief) was achieved with short time to pain relief in trial and maintained with limited device programming after permanent implant. The data presented here provide insight into the programming required during the trial and implant stages to obtain and maintain therapeutic efficacy.

Cervical Spinal Cord Stimulation for Failed Neck Surgery Syndrome

PURPOSE OF REVIEW

Cervical spine pain with or without radicular symptoms is a common condition leading to high utilization of the healthcare system with over 10 million medical visits per year. Many patients undergo surgical interventions and unfortunately are still left with neck and upper extremity pain, sometimes referred to as "Failed Neck Surgery Syndrome." When these options fail, cervical spinal cord stimulation can be a useful tool to decrease pain and suffering as well as reduce prescription medication use.

RECENT FINDINGS

Spinal cord stimulation is a well-established therapy for chronic back and leg pain and is becoming more popular for neck and upper extremity pain. Recent studies have explored cervical spinal cord stimulation with successful outcomes regarding improved pain scores, functional outcomes, and reduction of prescription medication use. Continued research into cervical spinal cord stimulation is essential for maximizing its therapeutic potential for patients with chronic neck and upper extremity pain. This review highlights the importance of cervical spinal cord stimulation as an option for patients with failed neck surgery syndrome.

History and Future of Spinal Cord Stimulation

Spinal cord stimulation (SCS) is a surgical treatment for chronic neuropathic pain refractory to medical management. An SCS system comprised one or more leads implanted in the epidural space, typically connected to an implantable pulse generator. This review discusses the history, indications, surgical technique, technological advances, and future directions of SCS.

Spinal cord stimulation in painful diabetic neuropathy: An overview

Up to 25% of people with diabetes develop painful diabetic neuropathy (PDN). The standard of care pharmacotherapies for PDN have limited efficacy with a considerable side effect profile. Spinal cord stimulation (SCS) is a form of electrical neurostimulation that modulates neural function via electrodes implanted into the spinal epidural space. While low frequency SCS has been shown to be potentially effective for treating pain associated with neuropathies, it masks pain perception by inducing paresthesia. Compared to low frequency SCS, high frequency (10 kHz) SCS delivers paresthesia-free therapy. As was shown in a randomized controlled trial, SENZA-PDN (NCT03228420), 10 kHz SCS is safe and effective for the treatment of painful diabetic neuropathy. 10 kHz SCS offered a comprehensive treatment that improved pain levels, sleep, quality of life, and neurological function. These improvements correlated with a high degree of patient satisfaction. 10 kHz SCS provides a safe, durable and effective treatment for PDN with the unique potential to improve neurological function. In patients for whom durable, effective treatments have been limited thus far, the findings of the SENZA-PDN study are encouraging.

Exploring Patient Satisfaction and Other Outcome Measures With Pain Relief in Spinal Cord Stimulation: A Single-Site, Cohort Audit

Context Spinal cord stimulation (SCS) is an approved treatment for chronic pain of neuropathic origin. Initial research suggests a close relationship between pain relief and patient satisfaction with SCS. Objectives To see whether similar patterns were observed in our center and to identify areas of improvement, this single-site, cohort audit explored the association between pain relief and satisfaction as well as specific factors that influence satisfaction at follow-up in patients with fully implanted SCS. Methods Age, gender, pain condition, SCS system, average pain (numerical rating scale, NRS), and worst pain (NRS) scores at baseline and the most recent follow-up visit were collected. Percentage change in average pain was calculated, and the patients were allocated to one of three pain improvement groups: <30%, 30%-50%, or >50%. A telephone survey explored patient outcomes including patient satisfaction, sleep, fatigue, quality of life (QoL), walking ability, and medication use. Chi-square tests of independence were performed. Results The final sample comprised 87 patients (<30%: n = 26; 30%-50%: n = 29; >50%: n = 32). The pain improvement group was significantly associated with satisfaction (p = 0.010): all patients in the >50% improvement group reported being either very satisfied or somewhat satisfied with SCS. The pain improvement group was also significantly associated with change in sleep (p < 0.001), fatigue (p = 0.001), QoL (p = 0.003), and opioid consumption (p = 0.010). Improvements were most frequently reported in the >50% improvement group. Conclusion Findings point to an association between pain relief and patient satisfaction with SCS. Other factors, including sleep, fatigue, QoL, and opioid consumption, may influence this association and deserve further exploration.

Current Neurostimulation Therapies for Chronic Pain Conditions

PURPOSE OF REVIEW

Neurostimulation treatment options have become more commonly used for chronic pain conditions refractory to these options. In this review, we characterize current neurostimulation therapies for chronic pain conditions and provide an analysis of their effectiveness and clinical adoption. This manuscript will inform clinicians of treatment options for chronic pain.

RECENT FINDINGS

Non-invasive neurostimulation includes transcranial direct current stimulation and repetitive transcranial magnetic stimulation, while more invasive options include spinal cord stimulation (SCS), peripheral nerve stimulation (PNS), dorsal root ganglion stimulation, motor cortex stimulation, and deep brain stimulation. Developments in transcranial direct current stimulation, repetitive transcranial magnetic stimulation, spinal cord stimulation, and peripheral nerve stimulation render these modalities most promising for the alleviating chronic pain. Neurostimulation for chronic pain involves non-invasive and invasive modalities with varying efficacy. Well-designed randomized controlled trials are required to delineate the outcomes of neurostimulatory modalities more precisely.

Novel Pulsed Ultrahigh-frequency Spinal Cord Stimulation Inhibits Mechanical Hypersensitivity and Brain Neuronal Activity in Rats after Nerve Injury

BACKGROUND

Spinal cord stimulation (SCS) is an important pain treatment modality. This study hypothesized that a novel pulsed ultrahigh-frequency spinal cord stimulation (pUHF-SCS) could safely and effectively inhibit spared nerve injury-induced neuropathic pain in rats.

METHODS

Epidural pUHF-SCS (± 3V, 2-Hz pulses comprising 500-kHz biphasic sinewaves) was implanted at the thoracic vertebrae (T9 to T11). Local field brain potentials after hind paw stimulation were recorded. Analgesia was evaluated by von Frey-evoked allodynia and acetone-induced cold allodynia.

RESULTS

The mechanical withdrawal threshold of the injured paw was 0.91 ± 0.28 g lower than that of the sham surgery (24.9 ± 1.2 g). Applying 5-, 10-, or 20-min pUHF-SCS five times every 2 days significantly increased the paw withdrawal threshold to 13.3 ± 6.5, 18.5 ± 3.6, and 21.0 ± 2.8 g at 5 h post-SCS, respectively (P = 0.0002, < 0.0001, and < 0.0001; n = 6 per group) and to 6.1 ± 2.5, 8.2 ± 2.7, and 14.3 ± 5.9 g on the second day, respectively (P = 0.123, 0.013, and < 0.0001). Acetone-induced paw response numbers decreased from pre-SCS (41 ± 12) to 24 ± 12 and 28 ± 10 (P = 0.006 and 0.027; n = 9) at 1 and 5 h after three rounds of 20-min pUHF-SCS, respectively. The areas under the curve from the C component of the evoked potentials at the left primary somatosensory and anterior cingulate cortices were significantly decreased from pre-SCS (101.3 ± 58.3 and 86.9 ± 25.5, respectively) to 39.7 ± 40.3 and 36.3 ± 20.7 (P = 0.021, and 0.003; n = 5) at 60 min post-SCS, respectively. The intensity thresholds for pUHF-SCS to induce brain and sciatic nerve activations were much higher than the therapeutic intensities and thresholds of conventional low-frequency SCS.

CONCLUSIONS

Pulsed ultrahigh-frequency spinal cord stimulation inhibited neuropathic pain-related behavior and paw stimulation evoked brain activation through mechanisms distinct from low-frequency SCS.

EDITOR’S PERSPECTIVE

Incidence of Neuraxial and Non-Neuraxial Hematoma Complications From Spinal Cord Stimulator Surgery: Systematic Review and Proportional Meta-Analysis

OBJECTIVE

The goal of this meta-analysis was to estimate the incidence of total hematomas, neuraxial hematomas, and non-neuraxial hematomas in patients who underwent temporary spinal cord stimulator (SCS) lead trial placement and permanent implantation of SCS leads and internal pulse generator (IPG).

MATERIALS AND METHODS

A comprehensive search was conducted of databases of any publications before October 21, 2021. Eligible study designs included randomized control trials and prospective or retrospective observational studies with more than ten patients. The primary outcome variables were the incidences of total hematomas, neuraxial hematomas, and non-neuraxial hematomas in patients with SCS. These dichotomous categorical outcomes were abstracted from studies after Freeman-Tukey arcsine square root transformation using random-effects meta-analysis (DerSimonian and Laird method). Pooled incidence rates and 95% CIs were calculated for each outcome variable.

RESULTS

A total of 40 studies met the inclusion criteria. Included in the neuraxial and non-neuraxial hematoma analyses were 4751 patients and 3862 patients, respectively. The pooled incidence of any hematoma in patients with SCS was 0.81% (95% CI, 0.45%-1.27%). The pooled incidence of neuraxial hematoma in patients with SCS was 0.32% (95% CI, 0.18%-0.50%). This included primarily epidural hematomas (11/4751) but also comprised an intracranial hemorrhage in a patient on enoxaparin bridge therapy from warfarin and one patient not on anticoagulation with an intracranial subdural hematoma that resulted in death. The pooled incidence of non-neuraxial hematomas in patients with SCS was 0.59% (95% CI, 0.29%-1.00%).

CONCLUSION

The overall incidence of hematomas in patients with temporary SCS trial lead placement and permanent SCS/IPG implantations is less than 1%. Furthermore, the incidence of neuraxial hematomas is less than 0.5%, which is of particular interest given the potential devastating consequences of this complication. The results of this study can be used to inform patients and implanting physicians on hematoma complications from SCS and highlight that the benefits of SCS outweigh the hematoma risks if anticoagulation is appropriately managed perioperatively.

Stimulating Results Signal a New Treatment Option for People Living With Painful Diabetic Neuropathy

BACKGROUND

Painful diabetic neuropathy (PDN) is a progressive condition that deprives many patients of quality of life. With limited treatment options available, successful pain management can be difficult to achieve.

METHODS

We reviewed results of recent data evaluating high frequency spinal cord stimulation (SCS).

RESULTS

from the SENZA-PDN randomized clinical trial (NCT03228420), the largest such trial to date, demonstrated 10-kHz spinal cord stimulation substantially reduced PDN refractory to conventional medical management along with improvements in health-related quality-of-life measures that were sustained over 12 months. These data supported the recent U.S. Food & Drug Administration (FDA) approval for 10-kHz SCS in PDN patients and contributed to the body of evidence on SCS available to health care professionals managing the effects of PDN.

CONCLUSION

High frequency spinal cord simulation appears to hold promise in treatment of painful diabetic neuropathy. We look forward to future works in the literature that will further elucidate these promising findings.

Incidence of Lead Migration With Loss of Efficacy or Paresthesia Coverage After Spinal Cord Stimulator Implantation: Systematic Review and Proportional Meta-Analysis of Prospective Studies and Randomized Clinical Trials

OBJECTIVE

The objective of this meta-analysis was to approximate the incidence of overall lead migration, clinically significant lead migration, and asymptomatic lead migration in patients who have undergone spinal cord stimulator implantation.

MATERIALS AND METHODS

A comprehensive literature search was performed for studies published before May 31, 2022. Only randomized controlled trials and prospective observational studies with more than ten patients were included. Two reviewers analyzed the articles from the literature search for final inclusion, after which, study characteristics and outcome data were extracted. The primary dichotomous categorical outcome variables were the incidence of overall lead migration, clinically significant lead migration (defined as lead migration resulting in loss of efficacy), and asymptomatic lead migration (defined as lead migration discovered incidentally on follow-up imaging) in patients with spinal cord stimulator implant. Freeman-Tukey arcsine square root transformation for meta-analysis of proportions using random effects (DerSimonian and Laird method) was used to calculate incidence rates for the outcome variables. Pooled incidence rates and 95% CIs were calculated for the outcome variables.

RESULTS

Fifty-three studies met the inclusion criteria, with a total of 2932 patients having received spinal cord stimulator implants. The pooled incidence of overall lead migration was 9.97% (95% CI of 7.62%-12.59%). Only 24 of the included studies commented on the clinical significance of reported lead migrations, of which every lead migration was clinically significant. In these 24 studies, 96% of the reported lead migrations required a revision procedure or explant. Unfortunately, no studies that reported lead migration commented on asymptomatic lead migrations; therefore, the incidence of asymptomatic lead migrations could not be defined.

CONCLUSIONS

This meta-analysis found that the rate of lead migration in patients who have received spinal cord stimulator implants is approximately one in ten patients. This likely closely approximates the incidence of clinically significant lead migration owing to the included studies not routinely performing follow-up imaging. Therefore, lead migrations were primarily discovered owing to loss of efficacy, and no included studies clearly reported asymptomatic lead migration. The results of this meta-analysis can be used to inform patients more accurately on the risks and benefits of spinal cord stimulator implantation.

A Feasibility Study Exploring Measures of Autonomic Function in Patients With Failed Back Surgery Syndrome Undergoing Spinal Cord Stimulation

OBJECTIVES

Failed back surgery syndrome (FBSS) is associated with impaired autonomic tone, characterized by sympathetic prevalence and vagal withdrawal. Although spinal cord stimulation (SCS) alleviates pain in FBSS, there is limited research investigating how SCS affects measures of autonomic function. This was a prospective, open-label, feasibility study exploring measures of autonomic function in patients with FBSS receiving SCS therapy.

MATERIALS AND METHODS

A total of 14 patients with FBSS were recruited for baseline measurements and underwent a trial of 10-kHz SCS. There were three failed trials, resulting in the remaining 11 participants receiving a fully implanted 10-kHz SCS system. One participant requested an explant, resulting in ten participants completing both baseline and follow-up (three to six months after SCS implant) measurements. Autonomic function was assessed using time- and frequency-domain heart rate variability (HRV), baroreceptor reflex sensitivity (BRS), and muscle sympathetic nerve activity (MSNA) using microneurography. Because this was a feasibility study, most of the analysis was descriptive. However, paired t-tests and Wilcoxon signed-rank tests tested for differences between baseline and follow-up.

RESULTS

In the whole (N = 14) and final (N = 10) samples, there was between-participant variation in baseline and follow-up measures. This, combined with a small sample, likely contributed to finding no statistically significant differences in any of the measures between baseline and follow-up. However, plotting baseline and follow-up scores for individual participants revealed that those who showed increases in MSNA frequency, square root of the mean of the squared differences between adjacent RR intervals (RMSSD), percentage of the number of RR intervals >50 ms (pRR50), total power, and up BRS between baseline and follow-up had distinct clustering of baseline values compared with those who showed decreases in these measures.

CONCLUSIONS

Findings from this feasibility study will aid with informing hypotheses for future research. A key aspect that should be considered in future research concerns exploring the role of baseline measures of autonomic function in influencing change in autonomic function with SCS therapy.

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

INTRODUCTION

A 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 METHODS

A 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.

RESULTS

Results 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).

DISCUSSION

These 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 REGISTRATION

The Clinicaltrials.gov registration number for the study is ACTRN12618001862235.

Indirect Comparison of 10 kHz Spinal Cord Stimulation (SCS) versus Traditional Low-Frequency SCS for the Treatment of Painful Diabetic Neuropathy: A Systematic Review of Randomized Controlled Trials

Spinal cord stimulation (SCS) is increasingly used to treat painful diabetic neuropathy (PDN). At the time of a recent meta-analysis in this field, data were only available from randomized controlled trials (RCTs) of traditional low-frequency SCS (LF-SCS). However, outcomes from high-frequency 10 kHz SCS treatment are now available. Our study aimed to systematically review the contemporary evidence for SCS in patients with lower limb pain due to PDN and include an indirect comparison of the high- and low-frequency modalities. We searched the PubMed/CENTRAL databases up to 18 August 2022, for peer-reviewed RCTs of SCS that enrolled PDN patients with lower limb pain symptoms. The quality of the evidence was assessed with the Cochrane Risk of Bias tool. Using SCS treatment arm data from the RCTs, we indirectly compared the absolute treatment effect of 10 kHz SCS and LF-SCS. Results are presented in tables and forest plots. This systematic review was reported according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) 2020 guidelines. Three RCTs met our eligibility criteria, including the recent 10 kHz SCS RCT (N = 216, 90 implanted) and 2 others that examined LF-SCS (N = 36, 17 implanted; N = 60, 37 implanted). Our analysis of 6-month data found clinically meaningful pain relief with each SCS modality. However, significantly greater pain reduction was identified for 10 kHz SCS over LF-SCS: average pain reduction in the 10 kHz SCS cohort was 73.7% compared with 47.5% in the pooled LF-SCS group (p < 0.0001). In the permanent implant subset, the 50% pain reduction responder rate was 83.3% in the 10 kHz SCS cohort versus 63.0% in the pooled LF-SCS group (p = 0.0072). The overall risk of bias of each included RCT was deemed high, mainly due to the absence of patient blinding. Our analysis indicates that paresthesia-free 10 kHz SCS can provide superior pain relief and responder rate over LF-SCS for managing PDN patients refractory to conventional medical management.

The painful shoulder arthroplasty: appropriate work-up and review of interventional pain treatments

Shoulder arthroplasty is a successful surgical procedure for several conditions when patients become refractory to conservative management modalities. Unfortunately, some patients experience persistent chronic pain after shoulder arthroplasty. These individuals should undergo a comprehensive evaluation by an orthopedic surgeon to determine whether structural pathology is responsible for the pain and to decide whether reoperation is indicated. At times, a surgical solution does not exist. In these circumstances, a thorough and specific plan for the management of persistent chronic pain should be developed and instituted. In this article, we review common reasons for persistent pain after shoulder arthroplasty and outline the evaluation of the painful shoulder arthroplasty. We then provide a thorough review of interventional pain management strategies. Finally, we hypothesize developments in our field that might provide better outcomes in the future for patients suffering with chronic intractable pain after shoulder arthroplasty.

Overcoming clinical challenges of refractory neuropathic pain

INTRODUCTION

: Refractory neuropathic pain (ReNP), and its definition, is widely disputed amongst clinicians due in part to unclear categorical diagnosing guidelines, overall time duration of neuropathic pain, and the exhaustiveness of treatment options. Usually ReNP is defined as chronic, intractable, and unresponsive neuropathic pain that have otherwise been untreatable.

AREAS COVERED

: In this narrative review, we discuss and summarize the effectiveness of prospective ReNP research conducted over the past 10 years. This research looks at pharmacological and interventional therapies in clinical trial settings. The pharmacological therapies discussed include the use of adjuvant treatments to improve the safety and efficacy of conventional approaches. Different modalities of administration, such as injection therapy and intrathecal drug delivery systems, provide targeted drug delivery. Interventional therapies such as neuromodulation, pulse radiofrequency, and nerve lesioning are more invasive, however, they are increasingly utilized in the field, as reflected in ongoing clinical trials.

EXPERT OPINION

: Based on the current data from RCTs and systematic reviews, it is clear that single drug therapy cannot be effective and has significant limitations. Transitioning to interventional modalities that showed more promising results sooner rather than later may be even more cost-efficient than attempting different conservative treatments with a high failure rate.

The Prevalence of Elevated Impedances and Magnetic Resonance Imaging Ineligibility Following Implantation of 10 kHz Spinal Cord Stimulation Devices: A Retrospective Review

OBJECTIVES

Spinal cord stimulation (SCS) is increasingly utilized in the treatment of multiple chronic pain conditions. However, patients will continue to experience other medical issues and the potential for future magnetic resonance imaging (MRI) needs must not be overlooked. SCS devices have device-specific MRI conditional labeling and if impedances are elevated the patient may not be able to obtain an MRI. With 10 kHz SCS devices specifically, an impedance value above 10,000 ohms (Ω) is MRI ineligible. The primary objective of this article was to report the incidence of elevated impedances with a multilumen lead design per electrode, per lead, and to describe the total number of MRI ineligible patients due to elevated impedances using 10 kHz SCS cutoff values. The secondary objective was to determine whether certain patient demographics or surgery characteristics put patients at increased risk of elevated impedances.

MATERIALS AND METHODS

We performed a retrospective review of 327 patients who were implanted with a 10 kHz SCS device between January 2015 and November 2020. Regression models were fitted to determine associations between MRI ineligibility status with clinical characteristics including age, sex, BMI, lead location, implantable pulse generator (IPG) location, and time since implant.

RESULTS

We found elevated impedances with subsequent MRI ineligibility in 13 patients (4.0%). Regression analysis did not identify any associations with MRI ineligibility and patient risk factors including age, sex, body mass index, lead location, IPG location, and follow-up time since implant.

CONCLUSION

We found the prevalence of elevated impedances above 10,000 Ω to be 4% of implanted patients. This information is important for patients and physicians alike and should be considered when device selection is occurring in the pre-operative visits.

High-Frequency 10-kHz Spinal Cord Stimulation Improves Health-Related Quality of Life in Patients With Refractory Painful Diabetic Neuropathy: 12-Month Results From a Randomized Controlled Trial

Objective

To evaluate high-frequency (10-kHz) spinal cord stimulation (SCS) treatment in refractory painful diabetic neuropathy.

Patients and Methods

A prospective, multicenter randomized controlled trial was conducted between Aug 28, 2017 and March 16, 2021, comparing conventional medical management (CMM) with 10-kHz SCS+CMM. The participants had hemoglobin A1c level of less than or equal to 10% and pain greater than or equal to 5 of 10 cm on visual analog scale, with painful diabetic neuropathy symptoms 12 months or more refractory to gabapentinoids and at least 1 other analgesic class. Assessments included measures of pain, neurologic function, and health-related quality of life (HRQoL) over 12 months with optional crossover at 6 months.

Results

The participants were randomized 1:1 to CMM (n=103) or 10-kHz SCS+CMM (n=113). At 6 months, 77 of 95 (81%) CMM group participants opted for crossover, whereas none of the 10-kHz SCS group participants did so. At 12 months, the mean pain relief from baseline among participants implanted with 10-kHz SCS was 74.3% (95% CI, 70.1-78.5), and 121 of 142 (85%) participants were treatment responders (≥50% pain relief). Treatment with 10-kHz SCS improved HRQoL, including a mean improvement in the EuroQol 5-dimensional questionnaire index score of 0.136 (95% CI, 0.104-0.169). The participants also reported significantly less pain interference with sleep, mood, and daily activities. At 12 months, 131 of 142 (92%) participants were "satisfied" or "very satisfied" with the 10-kHz SCS treatment.

Conclusion

The 10-kHz SCS treatment resulted in substantial pain relief and improvement in overall HRQoL 2.5- to 4.5-fold higher than the minimal clinically important difference. The outcomes were durable over 12 months and support 10-kHz SCS treatment in patients with refractory painful diabetic neuropathy.

Trial registration

clincaltrials.gov Identifier: NCT03228420.

Single-interface bioelectronic medicines - concept, clinical applications and preclinical data

Presently, large groups of patients with various diseases are either intolerant, or irresponsive to drug therapies and also intractable by surgery. For several diseases, one option which is available for such patients is the implantable neurostimulation therapy. However, lacking closed-loop control and selective stimulation capabilities, the present neurostimulation therapies are not optimal and are therefore used as only "third" therapeutic options when a disease cannot be treated by drugs or surgery. Addressing those limitations, a next generation class of closed-loop controlled and selective neurostimulators generically named bioelectronic medicines seems within reach. A sub-class of such devices is meant to monitor and treat impaired functions by intercepting, analyzing and modulating neural signals involved in the regulation of such functions using just one neural interface for those purposes. The primary objective of this review is to provide a first broad perspective on this type of single-interface devices for bioelectronic therapies. For this purpose, the concept, clinical applications and preclinical studies for further developments with such devices are here analyzed in a narrative manner.

Efficacy of interventions to reduce long term opioid treatment for chronic non-cancer pain: systematic review and meta-analysis

OBJECTIVE

To review interventions to reduce long term opioid treatment in people with chronic non-cancer pain, considering efficacy on dose reduction and discontinuation, pain, function, quality of life, withdrawal symptoms, substance use, and adverse events.

DESIGN

Systematic review and meta-analysis of randomised controlled trials and non-randomised studies of interventions.

DATA SOURCES

Medline, Embase, PsycINFO, CINAHL, and the Cochrane Library searched from inception to July 2021. Reference lists and previous reviews were also searched and experts were contacted.

ELIGIBILITY CRITERIA FOR STUDY SELECTION

Original research in English. Case reports and cross sectional studies were excluded.

DATA EXTRACTION AND SYNTHESIS

Two authors independently selected studies, extracted data, and used the Cochrane risk-of-bias tools for randomised and non-randomised studies (RoB 2 and ROBINS-I). Authors grouped interventions into five categories (pain self-management, complementary and alternative medicine, pharmacological and biomedical devices and interventions, opioid replacement treatment, and deprescription methods), estimated pooled effects using random effects meta-analytical models, and appraised the certainty of evidence using GRADE (grading of recommendations, assessment, development, and evaluation).

RESULTS

Of 166 studies meeting inclusion criteria, 130 (78%) were considered at critical risk of bias and were excluded from the evidence synthesis. Of the 36 included studies, few had comparable treatment arms and sample sizes were generally small. Consequently, the certainty of the evidence was low or very low for more than 90% (41/44) of GRADE outcomes, including for all non-opioid patient outcomes. Despite these limitations, evidence of moderate certainty indicated that interventions to support prescribers' adherence to guidelines increased the likelihood of patients discontinuing opioid treatment (adjusted odds ratio 1.5, 95% confidence interval 1.0 to 2.1), and that these prescriber interventions as well as pain self-management programmes reduced opioid dose more than controls (intervention v control, mean difference -6.8 mg (standard error 1.6) daily oral morphine equivalent, P<0.001; pain programme v control, -14.31 mg daily oral morphine equivalent, 95% confidence interval -21.57 to -7.05).

CONCLUSIONS

Evidence on the reduction of long term opioid treatment for chronic pain continues to be constrained by poor study methodology. Of particular concern is the lack of evidence relating to possible harms. Agreed standards for designing and reporting studies on the reduction of opioid treatment are urgently needed.

REVIEW REGISTRATION

PROSPERO CRD42020140943.

Neuromodulation in the Treatment of Painful Diabetic Neuropathy: A Review of Evidence for Spinal Cord Stimulation

BACKGROUND

Neuropathies, the most common complication of diabetes, manifest in various forms, including entrapments, mononeuropathies or, most frequently, a distal symmetric polyneuropathy. Painful diabetic neuropathy (PDN) in the classic "stocking" distribution is a disease of increasing prevalence worldwide and a condition for which standard medical treatment only provides modest relief. Neuromodulation offers a potential alternative to pharmacotherapies given its demonstrated efficacy in other refractory chronic neuropathic pain syndromes. High-quality evidence from randomized controlled trials (RCTs) is available in these other settings for two approaches to spinal cord stimulation (SCS): (1) conventional low-frequency SCS (LF-SCS), which modulates axonal activity in the dorsal column and is paresthesia-dependent, and (2) high-frequency SCS delivered at 10 kilohertz (10 kHz SCS), which targets neurons in the superficial dorsal horn and is paresthesia-independent.

METHOD

This review examines the evidence for SCS from published RCTs as well as prospective studies exploring the safety and effectiveness of treating PDN with neuromodulation.

RESULTS

Two RCTs enrolling 60 and 36 participants with PDN showed treatment with LF-SCS reduced daytime pain by 45% to 55% for up to two years. An RCT testing 10 kHz SCS versus conventional medical management (CMM) in 216 participants with PDN revealed 76% mean pain relief after six months of stimulation. None of the studies revealed unexpected safety issues in the use of neuromodulation in this patient population.

CONCLUSION

These well-designed RCTs address the unmet need for improved PDN therapies and provide data on the safety, effectiveness, and durability of SCS therapy.

A Real-World Analysis of High-Frequency 10 kHz Spinal Cord Stimulation for the Treatment of Painful Diabetic Peripheral Neuropathy

BACKGROUND

Diabetes is one of the most prevalent chronic health conditions and diabetic neuropathy one of its most prevalent and debilitating complications. While there are treatments available for painful diabetic peripheral neuropathy (pDPN), their effectiveness is limited.

METHOD

This retrospective, multi-center, real-world review assessed pain relief and functional improvements for consecutive patients with diabetic neuropathy aged ≥18 years of age who were permanently implanted with a high-frequency (10 kHz) spinal cord stimulation (SCS) device. Available data were extracted from a commercial database.

RESULTS

In total 89 patients consented to being included in the analysis. Sixty-one percent (54/89) of participants were male and the average age was 64.4 years (SD = 9.1). Most patients (78.7%, 70/89) identified pain primarily in their feet or legs bilaterally. At the last assessment, 79.5% (58/73) of patients were treatment responders, defined as having at least 50% patient-reported pain relief from baseline. The average time of follow-up was 21.8 months (range: 4.3 to 46.3 months). A majority of patients reported improvements in sleep and overall function relative to their baseline.

CONCLUSIONS

This real-world study in typical clinical practices found 10 kHz SCS provided meaningful pain relief for a substantial proportion of patients refractory to current pDPN management, similar to published literature. This patient population has tremendous unmet needs and this study helps demonstrate the potential for 10 kHz SCS to provide an alternative pain management approach.

The Role of Spinal Cord Stimulation in Reducing Opioid Use in the Setting of Chronic Neuropathic Pain: A Systematic Review

OBJECTIVE

The aim was to examine research on the impact of spinal cord stimulation (SCS) on the reduction of preimplantation opioid dose and what preimplantation opioid dose is associated with a reduction or discontinuation of opioid use postimplantation.

METHODS

Systematic review of literature from PubMed, Web of Science, and Ovid Medline search of "opioid" and "pain" and "spinal cord stimulator." Inclusion criteria included original research providing data on SCS preimplantation opioid dosing and 12 months postimplantation opioid dosing or that correlated specific preimplantation opioid dose or opioid dose cutoff with significantly increased likelihood of opioid use discontinuation at 12 months postimplantation.

RESULTS

Systematic review of the literature yielded 17 studies providing data on pre-SCS and post-SCS implantation dose and 4 providing data on the preimplantation opioid dose that significantly increased likelihood of opioid use discontinuation at 12 months postimplantation. Data from included studies indicated that SCS is an effective tool in reducing opioid dose from preimplantation levels at 12 months postimplantation. Data preliminarily supports the assertion that initiation of SCS at a preimplantation opioid dose of ≤20 to ≤42.5 morphine milligram equivalents increases the likelihood of postimplantation elimination of opioid use.

DISCUSSION

SCS is an effective treatment for many types of chronic pain and can reduce or eliminate chronic opioid use. Preimplantation opioid dose may impact discontinuation of opioid use postimplantation and the effectiveness of SCS in the relief of chronic pain. More research is needed to support and strengthen clinical recommendations for initiation of SCS use at lower daily opioid dose.

Health-Care Utilization and Outcomes with 10 kHz Spinal Cord Stimulation for Chronic Refractory Pain

Background

Chronic pain is a common condition associated with decreased quality of life and increased health-care costs. Opioid analgesics are routinely used to treat chronic pain despite limited evidence of long-term efficacy. Spinal cord stimulation at a frequency of 10 kilohertz (10kHz-SCS) has been shown to be effective for treating chronic pain.

Objective

This study was conducted to evaluate the effects of 10kHz-SCS on patients’ pain intensity, volume of pain interventions, and opioid intake in a real-world setting.

Study Design

This study was a retrospective review of patient data.

Setting

The study was conducted at a single, community-based clinic.

Methods

Outcomes including pain relief, quality of life, opioid intake, and rate of health-care usage were evaluated using data from patients who were implanted with a 10kHz-SCS device to treat chronic pain. These outcomes were then compared for the pre- and post-implant periods.

Results

A total of 47 patients with a mean follow-up duration of 15.6 ± 6.2 months were included in this analysis. Mean pain relief was 73 ± 22% and 89% were responders at the final follow-up visit. The rate of medical interventions fell from 3.48±3.05 per year before starting 10kHz-SCS to 0.49±1.16 per year afterward (P < 0.001). Of 30 patients with available opioid consumption data, 89% maintained or decreased their intake after implant.

Conclusion

Retrospective data from a single center, with minimal exclusion criteria shows clinically significant pain relief with 10kHz-SCS, accompanied by significant indirect benefits including stable or reduced opioid use and reduced interventional procedures.

Pain Relief and Safety Outcomes with Cervical 10 kHz Spinal Cord Stimulation: Systematic Literature Review and Meta-analysis

BACKGROUND

Chronic pain in head, neck, shoulders and upper limbs is debilitating, and patients usually rely on pain medications or surgery to manage their symptoms. However, given the current opioid epidemic, non-pharmacological interventions that reduce pain, such as spinal cord stimulation (SCS), are needed. The purpose of this study was to review the evidence on paresthesia-free 10 kHz SCS therapy for neck and upper extremity pain.

METHODS

Systematic literature search was performed for studies reporting outcomes for cervical 10 kHz SCS using date limits from May 2008 to November 2020. The study results were analyzed and described qualitatively. Additionally, when feasible, meta-analyses of the outcome data, with 95% confidence intervals (CIs), were conducted using both the fixed-effects (FE) and random-effects (RE) models.

RESULTS

A total of 15 studies were eligible for inclusion. The proportion of patients who achieved ≥ 50% pain reduction was 83% (95% CI 77-89%) in both the FE and RE models. The proportion of patients who reduced/eliminated their opioid consumption was 39% (95% CI 31-46%) in the FE model and 39% (95% CI 31-48%) in the RE model. Pain or discomfort with the implant, lead migration, and infections were potential risks following cervical SCS. Explant rate was 0.1 (95% CI 0.0-0.2) events per 100 person-months, and no patients in the included studies experienced a neurological complication or paresthesia.

CONCLUSION

Findings suggest 10 kHz SCS is a promising, safe, minimally invasive alternative for managing chronic upper limb and neck pain.

A narrative review and future considerations of spinal cord stimulation, dorsal root ganglion stimulation and peripheral nerve stimulation

PURPOSE OF REVIEW

In recent years, neuromodulation has experienced a renaissance. Novel waveforms and anatomic targets show potential improvements in therapy that may signify substantial benefits. New innovations in peripheral nerve stimulation and dorsal root ganglion stimulation have shown prospective evidence and sustainability of results. Sub-perception physiologic bursting, high-frequency stimulation and feedback loop mechanisms provide significant benefits over traditional tonic spinal cords stimulation (SCS) in peer reviewed investigations. We reviewed the themes associated with novel technology in the context of historical stalwart publications.

RECENT FINDINGS

New innovations have led to better nerve targeting, improvements in disease-based treatment, and opioid alternatives for those in chronic pain. In addition, new neural targets from both structural and cellular perspectives have changed the field of Neurostimulation.

SUMMARY

For many years, tonic SCS was representative of neuromodulation, but as this review examines, the progression of the field in the past decade has reshaped patient options.

Efficacy and Safety of 10 kHz Spinal Cord Stimulation Using Cervical and Thoracic Leads: A Single-Center Retrospective Experience

INTRODUCTION

Spinal cord stimulation (SCS) with lower thoracic leads has been studied extensively. However, the evidence base for cervical SCS is less well developed, and reports of multiarea SCS lead placement are uncommon. Therefore, this single-center retrospective study evaluated outcomes from 10-kHz SCS with cervical or combined cervical and thoracic lead placement.

METHOD

All patients that underwent a 10-kHz SCS trial with either cervical or combined cervical and thoracic lead placement between 2015 and 2020 were included in our study. We reviewed patient's charts for demographic information, lead placement, and pain scores up to 48 months after implantation.

RESULTS

Of the 105 patients that underwent a 10-kHz SCS trial during the review period, 92 (88%) had back/neck or extremity pain that responded to therapy (≥ 50% pain relief from baseline) and received a permanent system. Sixty-two of these patients (67%) were implanted with combined cervical and thoracic leads, while 30 (33%) received cervical-only leads. Pain relief in both regions exceeded 60% at most visits throughout the 48-month study period. Throughout follow-up, the responder rate in both pain areas was consistently ≥ 70%. No unexpected adverse events occurred.

CONCLUSION

The 10-kHz SCS provided effective and durable pain relief with either cervical or combined cervical and thoracic leads. The efficacy and safety profile of both applications appears to be comparable to lower thoracic SCS. Our results suggest that 10-kHz SCS is a useful paresthesia-free therapeutic option for chronic neuropathic pain originating in the cervical area, as well as more complex multiarea pain presentations.

Spinal cord stimulation for the management of painful diabetic neuropathy: a systematic review and meta-analysis of individual patient and aggregate data

ABSTRACT

Spinal cord stimulation (SCS) has been suggested as a treatment option for patients with painful diabetic neuropathy (PDN). We conducted a systematic review and undertook a meta-analysis on individual patient data from randomised controlled trials (RCTs) to assess the effectiveness of SCS for the management of PDN. Electronic databases were searched from inception to May 2020 for RCTs of SCS for PDN. Searches identified 2 eligible RCTs (total of 93 patients with PDN) and 2 long-term follow-up studies of one of the RCTs. Individual patient data were obtained from the authors of one of these RCTs. Meta-analysis showed significant and clinically meaningful reductions in pain intensity for SCS compared with best medical therapy alone, pooled mean difference (MD) -3.13 (95% confidence interval [CI]: -4.19 to -2.08) on a 10-point scale at the 6-month follow-up. More patients receiving SCS achieved at least a 50% reduction in pain intensity compared with best medical therapy, pooled risk ratio 0.08 (95% CI: 0.02-0.38). Increases were observed for health-related quality of life assessed as EQ-5D utility score (pooled MD 0.16, 95% CI: 0.02-0.30) and visual analogue scale (pooled MD 11.21, 95% CI: 2.26-20.16). Our findings demonstrate that SCS is an effective therapeutic adjunct to best medical therapy in reducing pain intensity and improving health-related quality of life in patients with PDN. Large well-reported RCTs with long-term follow-up are required to confirm these results.

High-frequency 10 kHz Spinal Cord Stimulation for Chronic Back and Leg Pain: Cost-consequence and Cost-effectiveness Analyses

OBJECTIVES

There is good evidence that spinal cord stimulation (SCS) is effective for reducing chronic back and leg pain (CBLP). SENZA randomized controlled trial showed high-frequency (10 kHz) stimulation (10 kHz-SCS) is clinically superior to traditional low-frequency SCS (LF-SCS).Undertake cost-consequence and cost-effectiveness analysis of 10 kHz-SCS compared with LF-SCS.

METHODS

A probabilistic decision tree and Markov decision analytic model was used to synthesize data on CBLP outcomes and costs over a 15-year time horizon from a UK National Health Service perspective using data from the SENZA randomized controlled trial and other publications. Results are expressed as incremental cost per quality-adjusted life year (QALY) in 2016 Pounds Sterling.

RESULTS

10 kHz-SCS is cost-saving and cost-effective compared with LF-SCS, with mean cost-savings of £7170 (95% confidence interval: £6767-£7573) and £3552 (95% confidence interval: £3313-£3792) per patient compared with nonrechargeable and rechargeable LF-SCS devices, respectively. 10 kHz-SCS has a 95% likelihood of being cost-effective at a willingness-to-pay threshold of £20,000 per QALY. Our findings were robust across a wide range of sensitivity analyses.

CONCLUSIONS

There is a strong economic case for choosing 10 kHz-SCS over LF-SCS for CBLP. Furthermore, 10 kHz-SCS has clinical advantages not captured in our analysis, including shorter, and more predictable procedure times.

Spinal cord stimulation for neuropathic pain

Spinal cord stimulation (SCS) is used for more than 40years to treat localized chronic medically refractory neuropathic pain involving limb(s) and trunk. The most frequent indications remain complex regional pain syndrome (CRPS) failed back surgery syndrome (FBSS), and peripheral neuropathy. Stimulation-induced paresthesias, perceived by the patient, prevent blinded evaluation and increase the placebo effect, decreasing the credibility of the tonic SCS efficacy. Retrospective studies reported that about 50% of the patients are improved more than 50% at short-term, but long-term improvement is less. Several comparative randomized trials (RCT) are now available. In CRPS, a RCT demonstrated the superiority of SCS plus physiotherapy compared to physiotherapy alone. In FBSS, two RCTs have shown that SCS was superior to reoperation and conventional medical treatment, (CMM) respectively. New stimulation waveforms, namely burst, high frequency (10KHz) stimulation and close-loop SCS, have been proposed recently to avoid the perception of paresthesias and/or increase the pain relief. RCTs in FBSS have suggested that these new SCS modalities were as least as efficient than conventional tonic SCS and perhaps slightly superior. Two RCTs confirmed SCS efficacy in painful diabetic neuropathy in comparison with CMM. Complications are frequent (hardware dysfunction or migration, superficial infection) but exceptionally serious. Consequently, the risk/benefit ratio is favorable to SCS, considering that chronic pain patients undergoing this procedure are usually resistant to all the other therapies.

Paresthesia-Based Versus High-Frequency Spinal Cord Stimulation: A Retrospective, Real-World, Single-Center Comparison

OBJECTIVE

Spinal cord stimulation (SCS) has become a common treatment modality for chronic pain of various etiologies. Over the past two decades, significant technological evolution has occurred in the SCS space, and this includes high-frequency (10 kHz) stimulation. Level I evidence exists reporting superiority of 10 kHz SCS over traditional SCS, however, conflicting reports have been published. The primary objective was to report site-collected real-world patient reported percentage improvement in pain scale (PR-PIPS) with traditional SCS and 10 kHz SCS from a single, academic medical center.

MATERIALS AND METHODS

This study was a single-center retrospective review to determine PR-PIPS of traditional SCS and 10 kHz SCS in those patients implanted for at least 12 months. Data were collected by two independent physicians not involved with the implant surgery to minimize bias in the data collection process. PR-PIPS and other clinical variables were abstracted either via chart review or via phone call for patients who were at least 12 months post-implant at the last clinical follow-up.

RESULTS

A total of 163 implanted patients (traditional stimulation n = 85; high-frequency stimulation n = 78) were identified. Twenty-two explants (traditional stimulation n = 10; high-frequency stimulation n = 12) were performed (13.5%). Seventy-five total remaining SCS implants utilizing traditional stimulation and 66 total remaining SCS implants utilizing high-frequency stimulation were included. There was no difference in PR-PIPS between traditional stimulation (50.6% ± 30.1%) and high-frequency stimulation (47.6% ± 31.5%) in the adjusted linear regression model in a variety of implant indications (p = 0.399). There was no difference in frequency of patient categorization into various thresholds of percentage pain relief based on type of stimulation. The most common reasons for explant were loss of efficacy (50.0%) and infection (40.0%) in the traditional cohort, and loss of efficacy (58.3%) in the high-frequency cohort.

CONCLUSIONS

This study adds further evidence to the published literature that successful long-term results can be achieved with SCS. Our retrospective analysis did not find a statistically significant difference in PR-PIPS between traditional stimulation and high-frequency stimulation in a variety of indications over an average follow-up of nearly two years. Notably, there were statistically significant differences in treatment indications and primary sites of pain between the two patient cohorts, and this should be considered when interpreting the results.

Ten kHz spinal cord stimulation for the treatment of chronic peripheral polyneuropathy: 12-Month results from prospective open-label pilot study

BACKGROUND

The goal of this study was to demonstrate that the paresthesia-independent 10 kHz spinal cord stimulation (SCS) can provide long-term pain relief in patients with peripheral polyneuropathy (PPN). Clinically diagnosed subjects with PPN refractory to conventional medical management were enrolled in this prospective, multicenter study between November 2015 and August 2016, after institutional review board approval and patient informed consent were obtained.

METHODS

Subjects underwent trial stimulation utilizing 2 epidural leads, and if successful, were implanted with a permanent 10 kHz SCS system and followed up for 12 months post-implant. Outcome measures included adverse events, pain, neurological assessments, disability, function, quality of life, pain interference, sleep, satisfaction, and global impression of change. Data are presented as descriptive statistics. Permanent implant population results are reported as mean ± standard error.

RESULTS

Twenty-one of the 26 trialed subjects had a successful trial and 18 received a permanent implant. All subjects had the leads placed anatomically without the need for paresthesia. Subjects experienced significant and sustained pain relief (at least 65% at all timepoints) whereas physicians noted improvements in neurological function. Significant improvements in disability, function, sleep, sensory, and affective dimensions of pain were reported at all timepoints. All adverse events were resolved without sequelae.

CONCLUSION

Findings from this study suggest that 10 kHz SCS may provide sustained pain relief and disability improvements in patients suffering from PPN.

Safety and Efficacy of 10 kHz Spinal Cord Stimulation for the Treatment of Refractory Chronic Migraine: A Prospective Long-Term Open-Label Study

BACKGROUND

Refractory chronic migraine (rCM) is a highly disabling condition for which novel safe and effective treatments are needed. Safety and long-term efficacy of paresthesia-free high cervical 10 kHz spinal cord stimulation (SCS) were here prospectively evaluated for the treatment of rCM.

MATERIALS AND METHODS

Twenty adults with rCM (mean numbers of preventive treatments failed: 12.2 ± 3.1) were enrolled in this single-center, open-label, prospective study and implanted with a 10 kHz SCS system (Senza™ system, Nevro Corp.), with the distal tip of the lead(s) positioned epidurally at the C2 vertebral level. Safety and effectiveness outcomes, such as adverse events, headache and migraine reductions, responder rates, Migraine Disability Assessment (MIDAS), Headache Impact Test-6 (HIT-6), and Migraine-Specific Quality-of-Life (MSQ), were captured up to 52 weeks after implantation.

RESULTS

Compared to baseline, at 52 weeks postimplantation, there was a significant reduction of mean monthly migraine days (MMD) by 9.3 days (p < 0.001). Sixty percent and 50% of patients obtained respectively at least 30% and at least 50% reduction in mean MMD. By week 52, 50% of patients' chronic pattern converted to an episodic pattern. The proportion of subjects classified with severe headache-related disability on the HIT-6, decreased from 100% to 60% at week 52. Meaningful improvements of headache-related quality of life measured by the MSQ scale were observed with mean gain of 24.9 ± 23.1 (p < 0.001) points at 52 weeks. No unanticipated adverse device effects occurred. No patients required any additional device surgical revision.

CONCLUSION

10 kHz SCS may a be safe and effective neurostimulation option for rCM patients. The paresthesia-free waveform constitutes an unprecedented advantage for future methodologically sound sham-controlled studies in headache neuromodulation.

Management of Chronic and Neuropathic Pain with 10 kHz Spinal Cord Stimulation Technology: Summary of Findings from Preclinical and Clinical Studies

Since the inception of spinal cord stimulation (SCS) in 1967, the technology has evolved dramatically with important advancements in waveforms and frequencies. One such advancement is Nevro’s Senza^® SCS System for HF10, which received Food and Drug and Administration (FDA) approval in 2015. Low-frequency SCS works by activating large-diameter Aβ fibers in the lateral discriminatory pathway (pain location, intensity, quality) at the dorsal column (DC), creating paresthesia-based stimulation at lower-frequencies (30–120 Hz), high-amplitude (3.5–8.5 mA), and longer-duration/pulse-width (100–500 μs). In contrast, high-frequency 10 kHz SCS works with a proposed different mechanism of action that is paresthesia-free with programming at a frequency of 10,000 Hz, low amplitude (1–5 mA), and short-duration/pulse-width (30 μS). This stimulation pattern selectively activates inhibitory interneurons in the dorsal horn (DH) at low stimulation intensities, which do not activate the dorsal column fibers. This ostensibly leads to suppression of hyperexcitable wide dynamic range neurons (WDR), which are sensitized and hyperactive in chronic pain states. It has also been reported to act on the medial pathway (drives attention and pain perception), in addition to the lateral pathways. Other theories include a reversible depolarization blockade, desynchronization of neural signals, membrane integration, glial–neuronal interaction, and induced temporal summation. The body of clinical evidence regarding 10 kHz SCS treatment for chronic back pain and neuropathic pain continues to grow. There is high-quality evidence supporting its use in patients with persistent back and radicular pain, particularly after spinal surgery. High-frequency 10 kHz SCS studies have demonstrated robust statistically and clinically significant superiority in pain control, compared to paresthesia-based SCS, supported by level I clinical evidence. Yet, as the field continues to grow with the technological advancements of multiple waveforms and programming stimulation algorithms, we encourage further research to focus on the ability to modulate pain with precision and efficacy, as the field of neuromodulation continues to adapt to the modern healthcare era.

Effect of High-frequency (10-kHz) Spinal Cord Stimulation in Patients With Painful Diabetic Neuropathy: A Randomized Clinical Trial

Question

Will 10-kHz spinal cord stimulation improve pain relief for patients with painful diabetic neuropathy refractory to medical management?

Findings

In this randomized clinical trial including 216 patients, there was a significant benefit of 10-kHz spinal cord stimulation, with 79% of treatment responders whose underlying neurological deficits did not worsen compared with 5% of controls treated with conventional medical management.

Meaning

Patients with painful diabetic neuropathy with inadequate pain relief despite best available medical treatments should be considered for 10-kHz spinal cord stimulation.

Importance

Many patients with diabetic peripheral neuropathy experience chronic pain and inadequate relief despite best available medical treatments.

Objective

To determine whether 10-kHz spinal cord stimulation (SCS) improves outcomes for patients with refractory painful diabetic neuropathy (PDN).

Design, Setting, and Participants

The prospective, multicenter, open-label SENZA-PDN randomized clinical trial compared conventional medical management (CMM) with 10-kHz SCS plus CMM. Participants with PDN for 1 year or more refractory to gabapentinoids and at least 1 other analgesic class, lower limb pain intensity of 5 cm or more on a 10-cm visual analogue scale (VAS), body mass index (calculated as weight in kilograms divided by height in meters squared) of 45 or less, hemoglobin A_1c (HbA_1c) of 10% or less, daily morphine equivalents of 120 mg or less, and medically appropriate for the procedure were recruited from clinic patient populations and digital advertising. Participants were enrolled from multiple sites across the US, including academic centers and community pain clinics, between August 2017 and August 2019 with 6-month follow-up and optional crossover at 6 months. Screening 430 patients resulted in 214 who were excluded or declined participation and 216 who were randomized. At 6-month follow-up, 187 patients were evaluated.

Interventions

Implanted medical device delivering 10-kHz SCS.

Main Outcomes and Measures

The prespecified primary end point was percentage of participants with 50% pain relief or more on VAS without worsening of baseline neurological deficits at 3 months. Secondary end points were tested hierarchically, as prespecified in the analysis plan. Measures included pain VAS, neurological examination, health-related quality of life (EuroQol Five-Dimension questionnaire), and HbA_1c over 6 months.

Results

Of 216 randomized patients, 136 (63.0%) were male, and the mean (SD) age was 60.8 (10.7) years. Additionally, the median (interquartile range) duration of diabetes and peripheral neuropathy were 10.9 (6.3-16.4) years and 5.6 (3.0-10.1) years, respectively. The primary end point assessed in the intention-to-treat population was met by 5 of 94 patients in the CMM group (5%) and 75 of 95 patients in the 10-kHz SCS plus CMM group (79%; difference, 73.6%; 95% CI, 64.2-83.0; P < .001). Infections requiring device explant occurred in 2 patients in the 10-kHz SCS plus CMM group (2%). For the CMM group, the mean pain VAS score was 7.0 cm (95% CI, 6.7-7.3) at baseline and 6.9 cm (95% CI, 6.5-7.3) at 6 months. For the 10-kHz SCS plus CMM group, the mean pain VAS score was 7.6 cm (95% CI, 7.3-7.9) at baseline and 1.7 cm (95% CI, 1.3-2.1) at 6 months. Investigators observed neurological examination improvements for 3 of 92 patients in the CMM group (3%) and 52 of 84 in the 10-kHz SCS plus CMM group (62%) at 6 months (difference, 58.6%; 95% CI, 47.6-69.6; P < .001).

Conclusions and Relevance

Substantial pain relief and improved health-related quality of life sustained over 6 months demonstrates 10-kHz SCS can safely and effectively treat patients with refractory PDN.

Trial Registration

ClincalTrials.gov Identifier: NCT03228420

Efficacy and Safety of 10 kHz Spinal Cord Stimulation for the Treatment of Chronic Pain: A Systematic Review and Narrative Synthesis of Real-World Retrospective Studies

10 kHz spinal cord stimulation (SCS) is increasingly utilized globally to treat chronic pain syndromes. Real-world evidence complementing randomized controlled trials supporting its use, has accumulated over the last decade. This systematic review aims to summarize the retrospective literature with reference to the efficacy and safety of 10 kHz SCS. We performed a systematic literature search of PubMed between 1 January 2009 and 21 August 2020 for English-language retrospective studies of ≥3 human subjects implanted with a Senza® 10 kHz SCS system and followed-up for ≥3 months. Two independent reviewers screened titles/abstracts of 327 studies and 46 full-text manuscripts. In total, 16 articles were eligible for inclusion; 15 reported effectiveness outcomes and 11 presented safety outcomes. Follow-up duration ranged from 6-34 months. Mean pain relief was >50% in most studies, regardless of follow-up duration. Responder rates ranged from 67-100% at ≤12 months follow-up, and from 46-76% thereafter. 32-71% of patients decreased opioid or nonopioid analgesia intake. Complication incidence rates were consistent with other published SCS literature. Findings suggest 10 kHz SCS provides safe and durable pain relief in pragmatic populations of chronic pain patients. Furthermore, it may decrease opioid requirements, highlighting the key role 10 kHz SCS can play in the medium-term management of chronic pain.

A Retrospective Review of Lead Migration Rate in Patients Permanently Implanted with Percutaneous Leads and a 10 kHz SCS Device

Background

Spinal cord stimulation (SCS) has been used over decades for pain management, but migration of percutaneous leads has been the most common complication. Better surgical techniques and newer SCS technologies likely reduced the incidence of lead migration requiring surgical revision, although data are sparse. This study aimed to retrospectively evaluate the incidence of clinically significant percutaneous lead migration in patients permanently implanted with a 10 kHz SCS system.

Methods

Consecutive patients with chronic trunk and/or limb pain, permanently implanted between January 2016 and June 2019, were included in the analysis. Data were collected from the hospital's electronic medical records and the manufacturer's database. Clinically significant lead migration, defined as diminished pain relief followed by surgery to correct lead location, was assessed at the 6-month follow-up.

Results

At the 6-month follow-up, there were no cases of clinically significant lead migration, average pain relief was 65.2%, 82% of patients had response (≥50% pain relief), improvement of function was noted in 72% of patients, and decrease of medication was observed in 42% of patients. Therapy efficacy was sustained in patients with >12 months follow-up; the average pain relief was 58.5%, and the response rate was 82%.

Conclusions

The surgical techniques in use today are designed to minimise the risk of percutaneous lead migration and may have reduced its incidence. In addition, new SCS systems may give greater opportunity to mitigate cases of minor lead movement using alternative stimulation programs.

Randomized Prospective Study in Patients With Complex Regional Pain Syndrome of the Upper Limb With High-Frequency Spinal Cord Stimulation (10-kHz) and Low-Frequency Spinal Cord Stimulation

OBJECTIVE

The objective of this prospective randomized study of cases and controls was to evaluate the efficacy of treatment with low-frequency spinal cord stimulation (LF-SCS) and 10 kHz spinal cord stimulation (10-kHz SCS) in patients diagnosed with complex regional pain syndrome type I (CRPS) with upper limb involvement.

MATERIALS AND METHODS

Fifty patients were randomized to receive conventional treatment or SCS with a commercially available low-frequency or 10-kHz system. Patients were assessed at 1, 3, 6, and 12 months. The primary endpoint was at 12-months post permanent implantation of the SCS devices. Outcome measures assessed included: Numerical Rating Scale (NRS), 12-Item Short-Format Health Survey (SF-12), Oswestry Disability Index (ODI), Study Sleep Scale medical outcomes (MOS-SS), Douleur Neuropathique 4 questions pain questionnaire (DN4), Patient Global Impression Scale on the impact of treatment improvement (PGI-I), Clinician Global Impression Scale on the impact of improving the patient (CGI-I).

RESULTS

Forty-one patients were finally included in the analysis, 19 patients in the conventional treatment group, 12 in the LF-SCS group, and 10 in the 10-kHz SCS group. At the primary endpoint, patients treated with LF-SCS presented improvements in the NRS and DN4 outcomes around 2.4 and 1.5 times above the minimal clinically important difference (MCID) thresholds. At the primary endpoint, patients treated with 10-kHz SCS presented improvements in the NRS and DN4 outcomes around 2 and 1.4 times above the MCID thresholds.

CONCLUSIONS

Patients experienced considerable improvement after SCS. The results show that LF-SCS has very good results when compared with conventional treatment. The results obtained with 10-kHz SCS are encouraging, with the advantages of the absence of paresthesia making it an alternative in the treatment of CRPS.

One-Year Results of Prospective Research Study Using 10 kHz Spinal Cord Stimulation in Persistent Nonoperated Low Back Pain of Neuropathic Origin: Maiden Back Study

PURPOSE

Spinal cord stimulation (SCS) is a recommended treatment for chronic neuropathic pain. Persistent nonoperative low back pain of neuropathic origin has profound negative impacts on patient's lives. This prospective, open label, research study aimed to explore the use of SCS in patients with associated features of central sensitisation such as allodynia and hyperalgesia.

MATERIALS AND METHODS

Twenty-one patients with back pain and hyperalgesia or allodynia who had not had prior spinal surgery underwent a SCS trial followed by full implantation. SCS comprised administering electrical impulses epidurally at a frequency of 10 kHz and pulse width of 30 μsec. Patients attended follow-up visits after 6 and 12 months of SCS. Repeated measure ANOVAs/Friedman tests explored change after 6 and 12 months of 10 kHz SCS. Independent sample t-tests/Mann-Whitney U tests examined differences in response after 12 months of 10 kHz SCS.

RESULTS

Back and leg pain, quality of life (QoL), pain-related disability, and morphine equivalence significantly improved compared with baseline following 6 and 12 months of 10 kHz SCS. There were no increases in the consumption of opioids, amitriptyline, gabapentin or pregabalin in any patient. After 12 months of treatment, 52% encountered ≥50% improvement in back pain, 44% achieved remission (0-3 cm back pain VAS), 40% reported ODI scores between 0 and 40 and 60% experienced a reduction of at least 10 ODI points. Patients reporting ≥10-point improvement in ODI had significantly longer pain history durations and experienced significantly greater improvements in back pain, leg pain and QoL than those reporting <10-point improvement in ODI.

CONCLUSION

The 10 kHz SCS improved back and leg pain, QoL, pain-related disability and medication consumption in patients with nonoperative back pain of neuropathic origin. With further research incorporating a sham control arm, the efficacy of 10 kHz SCS in this patient cohort will become more established.

Neuromodulatory hacking: a review of the technology and security risks of spinal cord stimulation

BACKGROUND

Spinal cord stimulation (SCS) is a neuromodulatory technique used to relieve chronic pain. Previous instances of malicious remote control of implantable medical devices, including insulin delivery pumps and implantable cardiac defibrillators, have been documented. Though no cases of neuromodulatory hacking have been recorded outside of the academic setting, an understanding of SCS technology and the possible consequences of manipulation is important in promoting safety.

METHODS

We review the components and implantation protocol of a SCS system, the functionality and technological specifications for SCS systems in the global market based on their device manuals, and patient- and clinician-specific adjustable factors. Furthermore, we assess documented instances of implantable medical device hacking and speculate on the potential harms of targeting SCS systems.

RESULTS

SCS systems from Abbott Laboratories, Boston Scientific, Medtronic, and Nevro have unique functionality and technological specifications. Six parameters in device control can potentially be targeted and elicit various harms, including loss of therapeutic effect, accelerated battery drainage, paresthesia in unintended locations, muscle weakness or dysfunction, tissue burn, and electrical shock.

CONCLUSIONS

Based on the history of implantable medical device hacking, SCS systems may also be susceptible to manipulation. As the prevalence of SCS use increases and SCS systems continuously evolve in the direction of wireless control and compatibility with mobile devices, appropriate measures should be taken by manufacturers and governmental agencies to ensure safety.

Pain relief and opioid usage in upper limb and neck pain patients after 10-kHz spinal cord stimulation treatment: subanalysis of USA studies

Aim: It is argued that chronic pain patients who reduce/eliminate their opioids may have compromised pain relief. This study therefore aimed to analyze if reduced opioid consumption associated with 10-kHz spinal cord stimulation adversely affected pain relief. Methods: Post hoc analysis was performed on data from two prospective studies in subjects with upper limbs and neck pain conducted in USA. Results & conclusion: A 10-kHz spinal cord stimulation treatment was associated with reduction in mean visual analog scale scores for upper limbs and neck pain and mean daily opioid consumption. Pain scores decreased in subjects who decreased opioid use and in those who maintained/increased use. Opioid reduction and pain relief was also achieved in subjects taking >90 mg morphine equivalents of opioids at baseline.

Ten kilohertz SCS for Treatment of Chronic Upper Extremity Pain (UEP): Results from Prospective Observational Study

Background

Chronic upper extremity pain (UEP) has complex etiologies and is often disabling. It has been shown that 10 kHz SCS can provide paresthesia-free and durable pain relief in multiple pain types and improve the quality of life of patients.

Objective

To gain additional evidence on the safety and effectiveness of 10 kHz SCS for the treatment of chronic UEP.

Study Design

It was a prospective, multicenter, and observational study. The study was registered on ClinicalTrials.gov prospectively (clinical trial identifier: NCT02703818).

Setting

Multicenter.

Patients Intervention and Main Outcomes

A total of 43 subjects with chronic UEP of ≥5 cm (on a 0-10 cm visual analog scale; VAS) underwent a trial of 10 kHz SCS, and subjects with ≥40% pain relief received a permanent implant. All subjects had upper limb pain at baseline, while some had concomitant shoulder or neck pain. Subject outcomes were assessed for 12 months, and the primary outcome was the responder rate (percentage of subjects experiencing ≥50% pain relief from baseline) at three months.

Results

Thirty-eight subjects successfully completed the trial (88.3% success rate), 33 received permanent implants (five withdrew consent), and 32 had device activation (per protocol population). There were no paresthesias or uncomfortable changes in stimulation related to changes in posture during the study and there were no neurological deficits. Responder rates at 12 months for upper limb, shoulder, and neck pain in per protocol population (N=32) were 78.1%, 85.2%, and 75.0%, respectively. At 12 months, 84.4% of subjects were satisfied or very satisfied with 10 kHz SCS, and 38.7% either reduced or eliminated opioid usage.

Conclusion

This study further supports the effectiveness of 10 kHz SCS for chronic UEP treatment and documents the safety profile of the therapy.

Clinical Trial Identifier

NCT02703818.

Overview of HF10 spinal cord stimulation for the treatment of chronic pain and an introduction to the Senza Omnia™ system

Chronic intractable pain affects a significant percentage of the worldwide population, and it is one of the most disabling and expensive health conditions across the globe. Spinal cord stimulation (SCS) has been used to treat chronic pain for a number of years, but high-frequency SCS was not the US FDA approved until 2015. In this review, we describe the history and development of high-frequency SCS and discuss the benefits of the Omnia™ implantable pulse generator. We also provide a thorough literature review of the published work, highlighting the efficacy and safety profiles of high-frequency SCS for the treatment of multiple chronic pain conditions. Lastly, we offer our outlook on future developments with the Omnia SCS system.

10 kHz spinal cord stimulation for the treatment of chronic back and/or leg pain: Summary of clinical studies

Chronic pain has a major impact on sufferers and their families. The associated health care costs are substantial. In the context of increasing prevalence, effective treatment options are ever more important. 10 kHz spinal cord stimulation has been shown to effectively provide pain relief, aid in opioid reduction, and improve quality of life in patients with chronic intractable pain. The present review aims to summarize the clinical evidence related to the use of 10 kHz SCS in chronic back and/or leg pain. We searched the PubMed database between 2009 and 2 June 2020 for articles reporting clinical studies that included at least 10 human subjects permanently treated with a 10 kHz SCS system (Senza^® system) for chronic back and/or leg pain for a minimum of 3 months. A randomized controlled trial (SENZA-RCT), as well as several prospective and retrospective studies, reported clinical outcomes in subjects with chronic back and leg pain treated with 10 kHz SCS. A high proportion of subjects (60%–80%) reported long-term response to therapy. Pain relief was provided without paresthesia. Other studies showed promising pain relief outcomes in subjects with back pain ineligible for spinal surgery, neuropathic limb pain, and in those with previously failed traditional low-frequency SCS. Most studies reported improved quality of life metrics and/or reduced opioid intake. Level 1 evidence has already been established for the use of 10 kHz SCS in treating chronic back and leg pain, corroborated by real-world, clinical experience. Exploratory studies also show the potential of the therapy in other refractory pain syndromes, although larger studies are desired to validate their findings. Overall, the literature suggests that 10 kHz SCS provides long-term pain relief in a high proportion of patients, along with improved quality of life and reduced opioid consumption.

A Prospective, Multi-Center, Clinical Trial of a 10-kHz Spinal Cord Stimulation System in the Treatment of Chronic Pelvic Pain

Background

Chronic pelvic pain (CPP) is a debilitating condition that often leads to disability and does not respond to conventional treatments. This study was conducted to evaluate the effects of paresthesia‐independent 10‐kHz spinal cord stimulation (SCS) in subjects with CPP.

Methods

This prospective, single‐arm pilot study enrolled subjects with clinical diagnoses of CPP and mean pain scores of ≥ 5.0 cm on a 10‐cm VAS. Subjects underwent trial stimulations with 10‐kHz SCS, and those who had successful trial stimulations (≥40% pain relief) received permanently implanted devices and were followed for 12 months.

Results

Of the 21 subjects who underwent the 10‐kHz SCS trial, 17 were successful and 14 subjects received permanent implants. No neurological deficits were observed in any subjects and all adverse events (AEs) were resolved without sequelae during the study period. Over 12 months, mean VAS scores decreased by 72% from baseline, and 10 of 13 subjects (77%) were responders (≥50% pain relief). Pain remission (VAS score ≤ 3.0 cm) was reported by 8 of 13 subjects (62%), and mean pain scores on the short‐form McGill Pain Questionnaire 2 decreased as well. Pain Disability Index scores declined by 29 points, and 85% of the subjects reported satisfaction.

Conclusions

Paresthesia‐independent stimulation with 10‐kHz SCS reduced pelvic pain in subjects with CPP and was not associated with any unexpected AEs. While larger, controlled studies are needed, results of this study suggest that this therapeutic modality could potentially treat patients with CPP while improving their quality of life.

Cascade Programming for 10 kHz Spinal Cord Stimulation: A Single Center Case Series of 114 Patients With Neuropathic Back and Leg Pain

OBJECTIVE

Ten kilohertz spinal cord stimulation (SCS) is usually initiated in a single-bipolar configuration over the radiological reference point T9/T10 intervertebral disc space for neuropathic back and leg pain. Cascade is a duty-cycled, multi-bipolar contact configuration across an entire eight-contact lead. Potential advantages by using a broader area of SCS coverage include mitigation against minor lead migration and a reduction in the need for reprogramming. We report here the results of a retrospective case series of 114 patients using Cascade.

MATERIALS AND METHODS

Retrospective data were collected over two years. We selected patients with neuropathic back with or without/leg pain who had a trial of SCS. Pain assessments using Numerical Rating Scales (NRS) and Patient Global Impression of Change (PGIC) scores were collected at baseline, six months, and last follow-up beyond 12 months (mean 15.1 months). Patients were programmed with 10 kHz SCS using Cascade during the trial, which was continued unless reporting inadequate pain relief. Morbidity and deviations from Cascade programming were also obtained.

RESULTS

At six months, 87 of 97 (90.6%) patients with active devices were using Cascade and 58 of 72 (81%) patients at the last follow-up >12 months. There was a significant reduction in back NRS (8.3 vs. 3.9 [p < 0.0001], N = 97) and leg pain (7.53 vs. 3.83 [p < 0.0001], N = 77) at 6 months and last follow-up >12 months back (8.3 vs. 3.95 [p < 0.0001] N = 72), leg (7.53 vs. 3.534 [p < 0.0001], N = 58). The PGIC score was 6 of 7 or all of 7 in 72% of patients (70/97) at six months and in 68% (49/72) of patients at the last follow-up beyond 12 months.

CONCLUSION

Cascade is an effective programming methodology that may have benefits over a single-bipole configuration for 10 kHz SCS, particularly during a trial of stimulation. Results from this study suggest it is a durable program for patients with neuropathic back and leg pain.