Pain relief and improvement in quality of life with 10 kHz SCS therapy: Summary of clinical evidence

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.

A pain in the pocket: Prevalence of pocket pain in patients with implantation of neuromodulation systems: A retrospective study

INTRODUCTION

Implantable pulse generator (IPG) is a neurostimulation therapy mediated by electrodes and surgically implanted in a subcutaneous "pocket" used for the control of numerous pathologies. This study examines both the prevalence of pain associated with IPG implantation ("pain pocket syndrome") and its associated characteristics.

MATERIALS AND METHODS

56 patients with an IPG were included in the study. A health questionnaire was conducted to determine the presence of pain associated with the pocket and its neuropathic characteristics, as well as associated aesthetic concerns, location, situations that accentuate or alleviate pain, medications used for baseline and pocket pain control and other factors associated.

RESULTS

Pain in the area of implantation of the IPG had a prevalence of 52.6% of patients (n = 27), in our sample, with a mean score on the visual analogic scale (VAS) of 4.9 points [3.9-5.8 points], with neuropathic characteristics in 53.3% (n = 16) of the patients with pain, with differences between the mean VAS score of the female (5.5 [4.3-5.8 points]) and males (3.5 points [2.1-4.9 points]) (p = 0.04).

CONCLUSION

Pocket pain is a condition with a higher prevalence than described in previous studies, being of a higher intensity in females, involving a moderate pain in the area of implantation of the neuromodulating therapy. This pain has neuropathic characteristics and could require a repositioning intervention. Hence, more studies in this field should be carried to detect and prevent this syndrome.

Variables associated with nonresponders to high-frequency (10 kHz) spinal cord stimulation

INTRODUCTION

The use of spinal cord stimulation (SCS) therapy to treat chronic pain continues to rise. Optimal patient selection remains one of the most important factors for SCS success. However, despite increased utilization and the existence of general indications, predicting which patients will benefit from neuromodulation remains one of the main challenges for this therapy. Therefore, this study aims to identify the variables that may correlate with nonresponders to high-frequency (10 kHz) SCS to distinguish the subset of patients less likely to benefit from this intervention.

MATERIALS AND METHODS

This was a retrospective single-center observational study of patients who underwent 10 kHz SCS implant. Patients were divided into nonresponders and responders groups. Demographic data and clinical outcomes were collected at baseline and statistical analysis was performed for all continuous and categorical variables between the two groups to calculate statistically significant differences.

RESULTS

The study population comprised of 237 patients, of which 67.51% were responders and 32.49% were nonresponders. There was a statistically significant difference of high levels of kinesiophobia, high self-perceived disability, greater pain intensity, and clinically relevant pain catastrophizing at baseline in the nonresponders compared to the responders. A few variables deemed potentially relevant, such as age, gender, history of spinal surgery, diabetes, alcohol use, tobacco use, psychiatric illness, and opioid utilization at baseline were not statistically significant.

CONCLUSION

Our study is the first in the neuromodulation literature to raise awareness to the association of high levels of kinesiophobia preoperatively in nonresponders to 10 kHz SCS therapy. We also found statistically significant differences with greater pain intensity, higher self-perceived disability, and clinically relevant pain catastrophizing at baseline in the nonresponders relative to responders. It may be appropriate to screen for these factors preoperatively to identify patients who are less likely to respond to SCS. If these modifiable risk factors are present, it might be prudent to consider a pre-rehabilitation program with pain neuroscience education to address these factors prior to SCS therapy, to enhance successful outcomes in neuromodulation.

Spinal Cord Stimulation for Painful Diabetic Neuropathy

Spinal cord stimulation (SCS) technology has been recently approved by the US Food and Drug Administration (FDA) for painful diabetic neuropathy (PDN). The treatment involves surgical implantation of electrodes and a power source that delivers electrical current to the spinal cord. This treatment decreases the perception of pain in many chronic pain conditions, such as PDN. The number of patients with PDN treated with SCS and the amount of data describing their outcomes is expected to increase given four factors: (1) the large number of patients with this diagnosis, (2) the poor results that have been obtained for pain relief with pharmacotherapy and noninvasive non-pharmacotherapy, (3) the results to date with investigational SCS technology, and (4) the recent FDA approval of systems that deliver this treatment. Whereas traditional SCS replaces pain with paresthesias, a new form of SCS, called high-frequency 10-kHz SCS, first used for pain in 2015, can relieve PDN pain without causing paresthesias, although not all patients experience pain relief by SCS. This article describes (1) an overview of SCS technology, (2) the use of SCS for diseases other than diabetes, (3) the use of SCS for PDN, (4) a comparison of high-frequency 10-kHz and traditional SCS for PDN, (5) other SCS technology for PDN, (6) deployment of SCS systems, (7) barriers to the use of SCS for PDN, (8) risks of SCS technology, (9) current recommendations for using SCS for PDN, and (10) future developments in SCS.

Use of spinal cord stimulation in treatment of intractable headache diseases

Headache diseases remain one of the leading causes of disability in the world. With the development of neuromodulation strategies, high cervical spinal cord stimulation (hcSCS) targeting the trigeminocervical complex has been deployed to treat refractory headache diseases. In this article, we review the proposed mechanism behind hcSCS stimulation, and the various studies that have been described for the successful use of this treatment strategy in patients with chronic migraine, cluster headache, and other trigeminal autonomic cephalalgias.

Precise management system for chronic intractable pain patients implanted with spinal cord stimulation based on a remote programming platform: study protocol for a randomized controlled trial (PreMaSy study)

BACKGROUND

Spinal cord stimulation (SCS) is a surgical technique used in patients with chronic intractable pain, and its effectiveness and safety have been validated by multiple studies. However, to maintain an optimal and steady long-term effect is still challenging. Here, we report a new management paradigm integrating smartphone application and remote programming. Chronic pain patients with SCS implants can monitor their pain status on the phone and change stimulation parameters accordingly. The PreMaSy study is a randomized controlled trial to evaluate the clinical effectiveness and safety of this precise management system.

METHODS

Patients with chronic intractable pain will be screened for eligibility, and 82 participants are anticipated to be enrolled in this trial. After the electrode implantation, the stimulation effectiveness will be tested. Participants with a reduction of more than 50% in the visual analog scale (VAS) will receive implantation of an implantable pulse generator and randomized (1:1) into the experimental group or control group. All participants will be asked to take online follow-ups and complete assessments using a smartphone application. Daily pain characteristic assessments and monthly quality of life questionnaires are integrated into the App, and participants will be required to complete these assessments. The daily VAS for pain intensity will be monitored and a threshold will be set based on baseline VAS score. The interventional appointment will be scheduled once the threshold is reached. The primary outcome is the health condition and quality of life assessed by the five-level EuroQol five-dimensional questionnaire (EQ-5D-5L). Utility values of EQ-5D-5L will be assessed at baseline and 1, 3, and 6 months post-operative.

DISCUSSION

The PreMaSy study aims to evaluate the effectiveness and safety of a novel App-based, patient-centered, self-assessment management system for chronic intractable pain. A randomized controlled trial is designed to test the non-inferiority of this precise management system compared to the monthly online follow-ups. It is also expected to yield valuable experiences regarding precision medicine.

TRIAL REGISTRATION

ClinicalTrials.gov NCT05761392. Registered on March 07, 2023.

High-frequency (10 kHz) spinal cord stimulation (SCS) as a salvage therapy for failed traditional SCS: A narrative review of the available evidence

INTRODUCTION

Traditional spinal cord stimulation (t-SCS) has been used to treat chronic pain for over 50 years. However, up to 30% of patients undergo explant, with the main indication being loss of efficacy (LoE), and few alternative treatment options exist for these patients. Strategies to mitigate LoE commonly include conversion to another type of SCS (termed 'salvage' or 'rescue'). This review summarizes the existing literature concerning the efficacy and safety of 10 kHz SCS as a salvage therapy.

METHODS

We searched PubMed, the Cochrane Library, ClinicalTrials.gov, and other sources between January 2009 and April 2021. Records were retained if the authors reported clinical outcomes with a minimum of ≥ 3 months of follow-up in patients implanted with a Senza® 10 kHz SCS system in an effort to treat t-SCS LoE.

RESULTS

Ten articles were eligible for inclusion, reporting 3 prospective studies and 7 retrospective reviews. In the single study that salvaged patients without a repeat trial prior to surgery, 81% of patients were responders (≥ 50% pain relief from baseline), with mean pain relief of 60%. Among repeat-trial studies, the responder rate ranged from 46% to 80%, and mean pain relief from 47% to 68%. No unanticipated therapy-related safety issues were reported among the included articles.

CONCLUSION

Preliminary data suggest that chronic back and/or leg pain patients with t-SCS LoE can experience improved and durable pain relief after conversion to 10 kHz SCS. However, additional research is needed to define predictors of success and establish whether salvage without a repeat trial is a viable conversion method.

High-frequency electrical stimulation attenuates neuronal release of inflammatory mediators and ameliorates neuropathic pain

BACKGROUND

Neuroinflammation is an important driver of acute and chronic pain states. Therefore, targeting molecular mediators of neuroinflammation may present an opportunity for developing novel pain therapies. In preclinical models of neuroinflammatory pain, calcitonin gene-related peptide (CGRP), substance P and high mobility group box 1 protein (HMGB1) are molecules synthesized and released by sensory neurons which activate inflammation and pain. High-frequency electrical nerve stimulation (HFES) has achieved clinical success as an analgesic modality, but the underlying mechanism is unknown. Here, we reasoned that HFES inhibits neuroinflammatory mediator release by sensory neurons to reduce pain.

METHODS

Utilizing in vitro and in vivo assays, we assessed the modulating effects of HFES on neuroinflammatory mediator release by activated sensory neurons. Dorsal root ganglia (DRG) neurons harvested from wildtype or transgenic mice expressing channelrhodopsin-2 (ChR2) were cultured on micro-electrode arrays, and effect of HFES on optogenetic- or capsaicin-induced neuroinflammatory mediator release was determined. Additionally, the effects of HFES on local neuroinflammatory mediator release and hyperalgesia was assessed in vivo using optogenetic paw stimulation and the neuropathic pain model of chronic constriction injury (CCI) of the sciatic nerve.

RESULTS

Light- or capsaicin-evoked neuroinflammatory mediator release from cultured transgenic DRG sensory neurons was significantly reduced by concurrent HFES (10 kHz). In agreement with these findings, elevated levels of neuroinflammatory mediators were detected in the affected paw following optogenetic stimulation or CCI and were significantly attenuated using HFES (20.6 kHz for 10 min) delivered once daily for 3 days.

CONCLUSION

These studies reveal a previously unidentified mechanism for the pain-modulating effect of HFES in the setting of acute and chronic nerve injury. The results support the mechanistic insight that HFES may reset sensory neurons into a less pro-inflammatory state via inhibiting the release of neuroinflammatory mediators resulting in reduced inflammation and pain.

Advances in Pain Medicine: a Review of New Technologies

PURPOSE OF REVIEW

This narrative review highlights the interventional musculoskeletal techniques that have evolved in recent years.

RECENT FINDINGS

The recent progress in pain medicine technologies presented here represents the ideal treatment of the pain patient which is to provide personalized care. Advances in pain physiology research and pain management technologies support each other concurrently. As new technologies give rise to new perspectives and understanding of pain, new research inspires the development of new technologies.

Machine Learning to Predict Successful Opioid Dose Reduction or Stabilization After Spinal Cord Stimulation

BACKGROUND

Spinal cord stimulation (SCS) effectively reduces opioid usage in some patients, but preoperatively, there is no objective measure to predict who will most benefit.

OBJECTIVE

To predict successful reduction or stabilization of opioid usage after SCS using machine learning models we developed and to assess if deep learning provides a significant benefit over logistic regression (LR).

METHODS

We used the IBM MarketScan national databases to identify patients undergoing SCS from 2010 to 2015. Our models predict surgical success as defined by opioid dose stability or reduction 1 year after SCS. We incorporated 30 predictors, primarily regarding medication patterns and comorbidities. Two machine learning algorithms were applied: LR with recursive feature elimination and deep neural networks (DNNs). To compare model performances, we used nested 5-fold cross-validation to calculate area under the receiver operating characteristic curve (AUROC).

RESULTS

The final cohort included 7022 patients, of whom 66.9% had successful surgery. Our 5-variable LR performed comparably with the full 30-variable version (AUROC difference <0.01). The DNN and 5-variable LR models demonstrated similar AUROCs of 0.740 (95% CI, 0.727-0.753) and 0.737 (95% CI, 0.728-0.746) ( P = .25), respectively. The simplified model can be accessed at SurgicalML.com .

CONCLUSION

We present the first machine learning-based models for predicting reduction or stabilization of opioid usage after SCS. The DNN and 5-variable LR models demonstrated comparable performances, with the latter revealing significant associations with patients' pre-SCS pharmacologic patterns. This simplified, interpretable LR model may augment patient and surgeon decision making regarding SCS.

Deep brain stimulation for phantom limb pain

Phantom limb pain is a rare cause of chronic pain in children but it is associated with extremely refractory pain and disability. The reason for limb amputation is often due to treatment for cancer or trauma and it has a lower incidence compared to adults. The mechanism of why phantom pain exists remains uncertain and may be a result of cortical reorganisation as well as ectopic peripheral input. Treatment is aimed at reducing both symptoms as well as managing pain related disability and functional restoration. Neuromodulatory approaches using deep brain stimulation for phantom limb pain is reserved for only the most refractory cases. The targets for brain stimulation include the thalamic nuclei and motor cortex. Novel targets such as the anterior cingulate cortex remain experimental as cases of serious adverse effects such as seziures have limited their widespread uptake. A multidisciplinary approach is crucial to successful rehabilitation using a biopsychosocial pain management approach.

When Two Is Better Than One: A Pilot Study on Transcranial Magnetic Stimulation Plus Muscle Vibration in Treating Chronic Pelvic Pain in Women

Chronic pelvic pain syndrome (CPPS) affects about 4–16% of adult women, and about one-third of them require medical assistance due to severe symptoms. Repetitive transcranial magnetic stimulation (rTMS) over the supplementary motor area (SMA) has been shown to manage pain in refractory CPPS. Focal muscle vibration (FMV) has also been reported to relieve pelvic pain. The objective of this study was to assess the feasibility and effect of rTMS coupled with FMV to reduce pain in seven adult women with refractory CPPS. This pilot, open-labeled, prospective trial examined treatment by 5 Hz rTMS over SMA and 150 Hz FMV over the perineum, suprapubic, and sacrococcygeal areas, with one daily session for five consecutive days for three weeks. We assessed tolerance and subjective pain changes (as per visual analog scale, VAS) until one month post-treatment, with a primary endpoint at day 7. No patients experienced serious adverse effects or a significant increase in pain. Six out of seven patients experienced a VAS improvement of at least 10% at T7; three of these individuals experienced a VAS improvement of more than 30%. Overall, we found a significant VAS reduction of 15 points (95% CI 8.4–21.6) at T7 (t = 6.3, p = 0.001; ES = 2.3 (1.1–3.9)). Three of the women who demonstrated a significant VAS reduction at T7 retained such VAS improvement at T30. VAS decreased by six points (95% CI 1.3–10.7) at T30 (t = 3.1, p = 0.02; ES = 1.5 (0.2–2.6)). This coupled approach seems promising for pain management in adult women with refractory CPPS and paves the way for future randomized controlled trials.

Subcutaneous Stimulation as Add-on Therapy to Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome Significantly Increases the Total Electrical Charge per Second: Aspects on Stimulation Parameters and Energy Requirements of the Implanted Neurostimulators

OBJECTIVE

In our previous multicenter randomized controlled trial, we demonstrated the clinical effectiveness of peripheral nerve field stimulation (PNFS) as add-on therapy to spinal cord stimulation (SCS) for the treatment of chronic back pain in patients with persistent spinal pain syndrome (PSPS) or failed back surgery syndrome (FBSS). To our knowledge, no previous study has investigated the effect of PNFS as an add-on to SCS on the energy consumption of the implanted neurostimulators. Therefore, in this study, we compared the specific stimulation parameters and energy requirements of a previously unreported group of patients with only SCS with those of a group of patients with SCS and add-on PNFS. We also investigated differences that might explain the need for PNFS in the treatment of chronic low back pain.

MATERIALS AND METHODS

We analyzed 75 patients with complete sets of stimulation parameters, with 21 patients in the SCS-only group and 54 patients in the SCS + PNFS group. Outcome measures were average visual analog scale score, SCS parameters (voltage, frequency, and pulse width), SCS charge per second, and total charge per second. We analyzed baseline characteristics and differences between and within groups over time.

RESULTS

Both groups had comparable patient characteristics at baseline and showed a significant decrease in back and leg pain. SCS charge per second did not significantly differ between the groups at baseline or at 12 months. The total charge per second was significantly higher in the active SCS + PNFS group than in the SCS-only group at baseline; in the SCS + PNFS group, this persisted for up to 12 months, and the SCS charge per second and total charge per second increased significantly over time.

CONCLUSIONS

Our results show that add-on PNFS increases the total charge per second compared with SCS alone, as expected. However, further research is needed because our results do not directly explain why some patients require add-on PNFS to treat low back pain.

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.

Non-Spinal Neuromodulation of the Lumbar Medial Branch Nerve for Chronic Axial Low Back Pain: A Narrative Review

Chronic low back pain remains highly prevalent, costly, and the leading cause of disability worldwide. Symptoms are complex and treatment involves an interdisciplinary approach. Due to diverse anatomical etiologies, treatment outcomes with interventional options are highly variable. A novel approach to treating chronic axial low back pain entails the use of peripheral nerve stimulation to the lumbar medial branch nerve, and this review examines the clinical data of the two different, commercially available, non-spinal neuromodulation systems. This review provides the clinician a succinct narrative that presents up-to-date data objectively. Our review found ten clinical studies, including one report of two cases, six prospective studies, and three randomized clinical trials published to date. Currently, there are different proposed mechanisms of action to address chronic axial low back pain with different implantation techniques. Evidence suggests that peripheral nerve stimulation of the lumbar medial branch nerve may be effective in improving pain and function in patients with chronic axial low back pain symptoms at short and long term follow up, with good safety profiles. Further long-term data is needed to consider this intervention earlier in the pain treatment algorithm, but initial data are promising.

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.

[Two cases of lumbar spinal stenosis with lumbar spondylolisthesis in elderly patients who benefited from spinal cord stimulation and an electrophysiological diagnosis]

Two elderly lumbar spinal stenosis (LSS) patients with spondylolisthesis underused with minimally invasive spinal cord stimulation (SCS) and electrophysiologic study of central motor conduction time (CMCT) and the cauda equina conduction time (CECT) were performed as spinal cord function evaluation. The usefulness of SCS treatment and electrophysiologic studies has been reported.A 68-year-old woman had bilateral leg pain, intermittent claudication, and left extensor hallucis longus (EHL) muscle weakness. The preoperative CMCT was prolonged on both sides, and the CECT was prolonged on the left, so corticospinal tract disorder and cauda equina disorder were suspected. Recovery of the left EHL 2 weeks after the operation and a tendency toward left-side improvement in the CMCT and CECT were seen at 10 weeks after surgery, and analgesics were no longer required by 4 months after surgery. A 79-year-old woman in failed back surgery syndrome had peroneal nerve palsy, lumbago, bilateral leg pain and muscle weakness, and gait disturbance at the first visit, along with bilaterally prolonged CMCT, suggesting corticospinal tract disorder. Two months after surgery, an improving trend in her muscle strength and CMCT were noted, and the peroneal nerve conduction velocity had been restored. In both of these cases, recovery of symptoms and improvement of in the CMCT and CECT were observed following SCS treatment without decompression of the organic compression of the nerve roots or dural canal in the lesion area. Minimally invasive SCS treatment may be useful in elderly patients with spinal diseases, and an electrophysiological diagnosis that can objectively evaluate the spinal cord function may be beneficial.

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.

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.

Twelve-Month results from multicenter, open-label, randomized controlled clinical trial comparing differential target multiplexed spinal cord stimulation and traditional spinal cord stimulation in subjects with chronic intractable back pain and leg pain

Background

Spinal cord stimulation (SCS) is a well‐established treatment for chronic intractable pain of the trunk and/or limbs; however, low back pain (LBP) is difficult to treat using traditional SCS. Differential Target Multiplexed spinal cord stimulation (DTM SCS) is an advanced approach inspired from animal studies demonstrating improved pain‐related behavior and pain‐relevant biological processes.

Objective

The purpose of this study was to compare the effectiveness of DTM SCS and traditional SCS in treating chronic LBP and leg pain (LP).

Methods

This prospective, postmarket randomized controlled trial compared DTM SCS to traditional SCS in patients with chronic LBP and LP. Primary end point was LBP responder rate (percentage of subjects with ≥ 50% relief) at 3 months. Noninferiority and superiority were assessed. Other outcomes included mean change in back and leg pain, responder rates, disability, global health, satisfaction, and safety profile throughout the 12‐month follow‐up.

Results

One hundred twenty‐eight subjects were randomized across 12 centers (67 DTM SCS and 61 traditional SCS). Of the 94 patients implanted, 46 subjects in each group completed the 3‐month assessment. LBP responder rate of 80.1% with DTM SCS was superior to 51.2% with traditional SCS (p = 0.0010). Mean LBP reduction (5.36 cm) with DTM SCS was greater than reduction (3.37 cm) with traditional SCS (p < 0.0001). These results were sustained at 6 months and 12 months. Safety profiles were similar between treatment groups.

Conclusion

Superiority of DTM SCS compared with traditional SCS for chronic LBP was demonstrated. Clinical improvements provided by DTM SCS were sustained over 12 months and are expected to significantly impact the management of chronic LBP.

Effects of Dorsal Column Spinal Cord Stimulation on Neuroinflammation: Revisiting Molecular Mechanisms and Clinical Outcomes on Chronic Lumbar/Leg Pain and Failed Back Surgery Syndrome

OBJECTIVE

In this narrative review, we reviewed and discussed current literature describing the molecular mechanisms leading to neuroinflammation and its role in the onset and progression of chronic neuropathic lumbar and leg pain in patients with persistent spinal pain syndrome. In addition, we reviewed the proposed mechanisms and impact of spinal cord stimulation (SCS) on neuroinflammation.

METHODS

A broad search of current literature in PubMed, Embase, Scopus, Cochrane library, Medline/Ovid, and Web of Science was performed using the following terms and their combinations: "biomarkers", "chronic back and leg pain", "cytokines", "neuroinflammation", "spinal cord stimulation (scs)," and "spinal cord modulation". We selected: 1) articles published in the English language between January 2000 and July 2020 2) preclinical and clinical data 3) case reports 4) meta-analysis and systematic reviews and 5) conference abstracts. Manuscripts not disclosing methodology or without full-text availability were excluded.

DISCUSSION

SCS techniques have gradually evolved since inception to include novel methods such as burst-SCS, high frequency SCS, and differential targeted multiplexed SCS. The incidence of chronic pain after spine surgery is highly variable, with at least one third of patients developing persistent spinal pain syndrome. Novel SCS techniques have been associated with improved clinical and functional outcomes thus increasing patient quality of life.

CONCLUSION

Currently, health care providers rely on different options and methods for SCS when treating patients with refractory chronic lumbar pain and persistent spinal pain syndrome. Nevertheless, compelling clinical trials remain necessary to elucidate the long-term benefits and mechanisms of neuromodulation of all different types of SCS.

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.

Amelioration of lower limb pain and foot drop with 10 kHz spinal cord stimulation: A case series

There are limited treatment options for patients with foot drop and associated lower back and/or leg pain. We present a case series of three patients who received permanent implantation of 10 kHz spinal cord stimulation (10 kHz SCS) devices. Following treatment, all patients reported sustained improvements in lower back and leg pain, foot mechanics and function which resulted in increased mobility and cessation of opioid use for pain management. Patients were followed up for approximately four years. Treatment with 10 kHz SCS may be a promising alternative to other interventional procedures commonly used for these patients.

Treatment of Painful Diabetic Neuropathy-A Narrative Review of Pharmacological and Interventional Approaches

Painful diabetic neuropathy (PDN) is a common complication of diabetes mellitus that is associated with a significant decline in quality of life. Like other painful neuropathic conditions, PDN is difficult to manage clinically, and a variety of pharmacological and non-pharmacological options are available for this condition. Recommended pharmacotherapies include anticonvulsive agents, antidepressant drugs, and topical capsaicin; and tapentadol, which combines opioid agonism and norepinephrine reuptake inhibition, has also recently been approved for use. Additionally, several neuromodulation therapies have been successfully used for pain relief in PDN, including intrathecal therapy, transcutaneous electrical nerve stimulation (TENS), and spinal cord stimulation (SCS). Recently, 10 kHz SCS has been shown to provide clinically meaningful pain relief for patients refractory to conventional medical management, with a subset of patients demonstrating improvement in neurological function. This literature review is intended to discuss the dosage and prospective data associated with pain management therapies for PDN.

Successful Treatment of Chronic Back and Leg Pain With Lower Than Usual Placement of High-Frequency Spinal Cord Stimulation in a Patient With Uncorrected Tethered Cord: Case Report

BACKGROUND AND IMPORTANCE

Tethered cord syndrome (TCS) often leads to severe back and leg pain. The typical treatment to stall disease progression is untethering surgery, but this is not always effective for pain. Spinal cord stimulation (SCS) is an efficacious treatment for neuropathic pain. However, it has seldom been utilized in TCS cases. Moreover, with cord elongation, ideal paddle placement is not certain.

CLINICAL PRESENTATION

We present the case of a 77-yr-old male with severe chronic lower-back and lower-extremity pain. Magnetic resonance imaging (MRI) showed severe lumbar spine degenerative changes, along with a previously undiagnosed spina bifida and conus medullaris termination at L5. We felt that SCS would be the best treatment avenue for his chief complaint of pain. Due to cord elongation, we trialed lower placement of the high-frequency (HF)-SCS system at T11-T12, which led to 80% improvement in pain symptoms within 1 wk and ability to walk for the first time in a year. At his first follow-up appointment, the patient endorsed 80% to 90% relief of his lower-back and bilateral lower-extremity pain, which improved to 100% relief at 12 mo at last visit.

CONCLUSION

Only 4 other reports were identified in the literature utilizing SCS in TCS cases. Our case adds to the limited body of literature that SCS is an effective therapy for pain in TCS and degenerative spine disease. Only 2 other reports employed lower than usual lead placement. Our case demonstrates that lead placement may need to be changed to accommodate the elongated cord.

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.

10 kHz Spinal Cord Stimulation for the Treatment of Failed Back Surgery Syndrome with Predominant Leg Pain: Results from a Prospective Study in Patients from the Dutch Healthcare System

INTRODUCTION

Persistent back/and or leg pain is a common outcome after spinal surgery (otherwise known as failed back surgery syndrome [FBSS]). Studies have shown that spinal cord stimulation (SCS) at 10 kHz provides effective analgesia in FBSS patients with both back and leg pain symptoms and in those with predominant back pain. This study is the first to evaluate the therapy in FBSS patients with predominant leg pain.

METHODS

The safety and efficacy of 10 kHz SCS was evaluated in an uncontrolled, open-label, prospective study of FBSS patients with predominant leg pain in the Netherlands. Follow-ups were performed at 1, 3, 6, and 12 months post implantation.

RESULTS

Sixty out of 68 patients (88%) experienced sufficient pain relief during a stimulation trial. Of these, 58 proceeded to permanent implantation of a 10 kHz SCS system. After 12 months of treatment, 80% of patients experienced ≥ 50% reduction in baseline leg pain, and a similar proportion (76%) experienced ≥ 50% reduction in baseline back pain. At least two-thirds of patients were also leg pain and back pain remitters (visual analog scale [VAS] ≤ 2.5 cm). The therapy was also associated with a general improvement in patients' quality of life, as measured by secondary outcomes including disability, perception of health improvement, mental well-being, and satisfaction. A positive impact on opioid consumption was also observed.

CONCLUSIONS

Consistent with previous findings, 10 kHz SCS for the treatment of FBSS patients with predominant radicular symptoms is safe and effective and is associated with improved quality of life.

Retrospective analysis on the effect of spinal cord stimulation on opioid consumption

Aim: Spinal cord stimulation (SCS) is used to clinically manage and/or treat several chronic pain etiologies. A limited amount is known about the influence on patients' use of opioid pain medication. This retrospective analysis evaluated SCS effect on opioid consumption in patients presenting with chronic pain conditions. Materials & methods: Sixty-seven patients underwent a temporary trial device, permanent implant or both. Patients were divided for assessment based on the nature of their procedure(s). Primary outcome was change in morphine equivalent dose (MED), ascertained from preoperative and postoperative medication reports. Results: Postoperative MED was significantly lower in patients who received some form of neuromodulation therapy. Pretrial patients reported an average MED of 41.01 ± 10.23 mg per day while post-trial patients reported an average of 13.30 ± 5.34 mg per day (p < 0.001). Pre-implant patients reported an average MED of 39.14 ± 13.52 mg per day while post-implant patients reported an average MED of 20.23 ± 9.01 mg per day (p < 0.001). There were no significant differences between pre-trial and pre-implant MED, nor between post-trial and post-implant MED. Of the 42 study subjects who reported some amount of pre-intervention opioid use, 78.57% indicated a lower MED (n = 33; p < 0.001), 16.67% indicated no change (n = 7) and 4.76% (n = 2) indicated a higher MED, following intervention. Moreover, SCS therapy resulted in a 26.83% reduction (p < 0.001) in the number of patients with MED >50 mg per day. Conclusion: Spinal cord stimulation may reduce opioid use when implemented appropriately. Neuromodulation may represent alternative therapy for alleviating chronic pain which may avoid a number of deleterious side effects commonly associated with opioid consumption.

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.

Pocket pain, does location matter: a single-centre retrospective study of patients implanted with a spinal cord stimulator

OBJECTIVES

Spinal cord stimulation (SCS) is an effective therapy for alleviating pain but reported complication rates vary between healthcare centers. This study explored the prevalence of pain associated with Implantable Pulse Generators (IPGs), the component that powers the SCS system.

METHODS

This was a retrospective, single site study analyzing data from 764 patients who had a fully implanted SCS between September 2013 and March 2020. Demographic data were collected together with IPG site and type, patient reported presence of IPG site pain, revisions, explants and baseline scores for neuropathic pain (using the Self-Administered Leeds Assessment of Neuropathic Symptoms and Signs questionnaire). Data were statistically analyzed by one-way analysis of variance, independent sample t-tests, X² tests of independence and logistic regression modeling.

RESULTS

IPG site pain occurred in 127 (17%) of 764 patients. These patients had higher baseline neuropathic pain scores than those who reported no IPG site pain. This complication was more common in females than males. The lowest rates of IPG site pain occurred after posterior chest wall placement and the highest rates occurred after abdominal implants. 7% of patients had revision surgery for IPG site pain (n=55) and 10 of 95 explanted patients stated that IPG site pain was a secondary influencing factor.

CONCLUSIONS

These findings suggest that IPG site pain is a common complication, contributing to SCS revisions and explantation. This study shows that anatomical factors and baseline characteristics of individual patients may contribute to IPG site pain and indicates that exploration of potential factors leading to IPG revision is required.

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.

10-kHz Spinal Cord Stimulation for Chronic Postsurgical Pain: Results From a 12-Month Prospective, Multicenter Study

Background

Chronic postsurgical pain (CPSP) can be caused by peripheral nerve injury (PNI) resulting from surgical procedures and has a significant neuropathic component. This prospective, single‐arm study was conducted to document the effectiveness of 10‐kHz spinal cord stimulation (10‐kHz SCS) as a treatment for patients with CPSP.

Methods

Subjects with CPSP who were refractory to conventional medical interventions and reported pain scores of ≥5 cm on a 10‐cm VAS underwent trial stimulations lasting up to 14 days. Epidural leads were implanted at locations appropriate for the primary area of pain, and trials resulting in ≥40% pain relief were considered successful. Subjects with successful trials underwent implantation with a permanent 10‐kHz SCS system and were followed for 12 months after implantation.

Results

Of the 34 subjects who underwent trial stimulation, 1 was withdrawn early and 29 (87.9%) had a successful trial and received a permanent implant. After 12 months of treatment, the mean VAS score decreased by 6.5 cm, the response rate was 88.0% (22/25), and 18 subjects (62.1%) were remitters with VAS scores sustained at ≤3.0 cm. Scores for all components of the short‐form McGill Pain Questionnaire 2 were significantly reduced, including affective descriptors of pain. Pain catastrophizing and vigilance, patient function, physical and mental well‐being, and sleep quality all improved over the course of the study. No neurologic deficits reported in the study.

Conclusions

10‐kHz SCS is effective and tolerated in patients with CPSP, and further study of its clinical application in this population is warranted.

Retrospective Analysis of Real-World Outcomes of 10 kHz SCS in Patients with Upper Limb and Neck Pain

BACKGROUND

Patients living with chronic upper limb and neck (ULN) pain are reliant on often ineffective therapies as they face limited options for effective long-term treatment.

OBJECTIVE

Prospective clinical studies have demonstrated that high-frequency spinal cord stimulation at 10 kHz (10 kHz SCS) is effective in treating chronic pain in multiple etiologies including ULN pain. This study aimed at validating the findings from clinical studies on ULN in a real-world cohort.

STUDY DESIGN

A retrospective, observational review.

SETTING

A multicenter review between April 2016 and August 2019.

PATIENTS AND METHODS

Anonymized data were extracted from a real-world database of 47 consecutive patients aged ≥18 years of age with chronic upper limb and/or neck pain who were trialed and permanently implanted with 10 kHz SCS. Patient-reported pain relief, quality of life, function, sleep and medication use were extracted from anonymised patient records where available. Responder rates, defined as the proportion of patients with at least 50% pain relief at the end of trial and the last visit after implantation, were calculated.

RESULTS

All patients reported successful response (≥50% pain relief) at the end of trial and >75% patients continued to respond to the therapy at the last follow-up period. Majority (72%) of patients reported improvement in function, about half of the patients (53%) reported improvement in sleep and one-third of the patients (36%) reported reducing their medication at last follow-up.

CONCLUSION

10 kHz SCS provides durable pain relief to patients with chronic upper limb and neck pain.

Improving care of chronic pain patients with spinal cord stimulator therapy amidst the opioid epidemic

The US government and other key stakeholders including professional medical bodies have amended recommendations in recent years to emphasize using no opioids or the lowest effective dose of opioids needed for treatment of chronic pain. However, there remains an unmet need for pain treatments that can both relieve the pain of patients and reduce the doses of opioids they require. The Center for Medicare and Medicaid Services (CMS) is currently considering such treatments through the SUPPORT ACT and has recently conferred with the Health and Human Services (HHS) Inter-agency Pain Management Task Force to consider such therapies. We reviewed literature evidence in PubMed on pain relief and opioid reduction following spinal cord stimulation (SCS) treatment. SCS presents an effective non-pharmacologic pain treatment modality that has been used for decades to reduce chronic pain from trauma or neuropathy and has been shown to either stabilize or reduce opioid use in some patients with painful conditions. A more recently developed high-frequency SCS modality, 10 kHz SCS, has the advantage of being paresthesia-independent. It has been shown to be associated with significant reductions in opioid consumption after stimulation therapy was initiated, and many patients even taking high doses of opioids (> 90 mg morphine equivalent dose per day) were able to reduce their opioid intake to levels associated with less risk. The evidence shows that reduction of opioids as early in the treatment process as possible is desirable to reduce patient risk and improve pain relief from stimulation therapy.

Pain relief and improvement in quality of life with 10 kHz SCS therapy: Summary of clinical evidence

Objective

Chronic pain is a prevalent condition which has a significant effect on the lives of those it impacts. High‐frequency 10 kHz spinal cord stimulation (10 kHz SCS) has been shown to provide paresthesia‐free pain relief for a wide variety of pain indications. This article summarizes the current and emerging data as they relate to the clinical use of the therapy in various pain syndromes.

Methods

A literature search was conducted using the PubMed electronic database using keywords related to 10 kHz SCS. The database was queried from 2013 to May 2019. Articles reporting clinical studies that included human subjects permanently treated with 10 kHz SCS (Senza® system) were included in the review. Recent and relevant conference proceedings known to the authors were also included.

Results

The selected literature demonstrated significant evidence for the efficacy of 10 kHz SCS in treating chronic back and leg pain (CBLP), including a randomized, controlled trial as well as prospective and retrospective studies. One‐year follow‐up responder rates (pain relief ≥50%) ranged from 60% to 80%. Other studies and case series showed promising outcomes in specific conditions, including nonsurgical refractory back pain, neuropathic limb pain, complex regional pain syndrome, chronic widespread pain, chronic pelvic pain, and intractable headache. Subgroup analyses also pointed toward the potential of 10 kHz SCS being successful when low‐frequency SCS has failed. The vast majority of these studies reported improved quality of life (QOL) metrics and/or reduced opioid consumption.

Conclusions

Level I evidence already exists for the efficacy of 10 kHz SCS in treating CBLP, supported by real‐world clinical experience. Other studies demonstrate the potential of the therapy across a range of chronic pain etiologies, although larger confirmatory studies are recommended. Overall, the literature suggests that the therapy is associated with improved QOL as well as reduced opioid consumption.