Sustained effectiveness of 10 kHz high-frequency spinal cord stimulation for patients with chronic, low back pain: 24-month results of a prospective multicenter study

Objective

The aim of this study was to investigate the long-term efficacy and safety of paresthesia-free high-frequency spinal cord stimulation (HF10 SCS) for the treatment of chronic, intractable pain of the low back and legs.

Design

Prospective, multicenter, observational study.

Method

Patients with significant chronic low back pain underwent implantation of a spinal cord stimulator capable of HF10 SCS. Patients' pain ratings, disability, sleep disturbances, opioid use, satisfaction, and adverse events were assessed for 24 months.

Results

After a trial period, 88% (72 of 82) of patients reported a significant improvement in pain scores and underwent the permanent implantation of the system. Ninety percent (65 of 72) of patients attended a 24-month follow-up visit. Mean back pain was reduced from 8.4 ± 0.1 at baseline to 3.3 ± 0.3 at 24 months (P < 0.001), and mean leg pain from 5.4 ± 0.4 to 2.3 ± 0.3 (P < 0.001). Concomitantly to the pain relief, there were significant decreases in opioid use, Oswestry Disability Index score, and sleep disturbances. Patients' satisfaction and recommendation ratings were high. Adverse Events were similar in type and frequency to those observed with traditional SCS systems.

Conclusions

In patients with chronic low back pain, HF10 SCS resulted in clinically significant and sustained back and leg pain relief, functional and sleep improvements, opioid use reduction, and high patient satisfaction. These results support the long-term safety and sustained efficacy of HF10 SCS.

Therapy-Related Explants After Spinal Cord Stimulation: Results of an International Retrospective Chart Review Study

Objectives

Clinical trials of spinal cord stimulation (SCS) have largely focused on conversion from trial to permanent SCS and the first years after implant. This study evaluates the association of type of SCS and patient characteristics with longer‐term therapy‐related explants.

Materials and Methods

Implanting centers in three European countries conducted a retrospective chart review of SCS systems implanted from 2010 to 2013. Ethics approval or waiver was obtained, and informed consent was not required. The chart review recorded implants, follow‐up visits, and date and reasons for any explants through mid‐2016. Results are presented using Cox regression to determine factors associated with explant for inadequate pain relief.

Results

Four implanting centers in three countries evaluated 955 implants, with 8720 visits over 2259 years of follow‐up. Median age was 53 years; 558 (58%) were female. Explant rate was 7.9% per year. Over half (94 of 180) of explants were for inadequate pain relief, including 32/462 (6.9%) of implants with conventional nonrechargeable SCS, 37/329 (11.2%) with conventional rechargeable and 22/155 (14.2%) with high‐frequency (10 kHz) rechargeable SCS. A higher explant rate was found in univariate regression for conventional rechargeable (HR 1.98, p = 0.005) and high‐frequency stimulation (HR 1.79, p = 0.035) than nonrechargeable SCS. After covariate adjustment, the elevated explant rate persisted for conventional rechargeable SCS (HR 1.95, p = 0.011), but was not significant for high‐frequency stimulation (HR 1.71, p = 0.069).

Conclusions

This international, real‐world study found higher explant rates for conventional rechargeable and high‐frequency SCS than nonrechargeable systems. The increased rate for conventional rechargeable stimulation persisted after covariate adjustment.

Stimulation of dorsal root ganglia for the management of complex regional pain syndrome: a prospective case series

BACKGROUND

Complex regional pain syndrome (CRPS) is a chronic and progressive pain condition usually involving the extremities and characterized by sensorimotor, vascular, and trophic changes. Spinal cord stimulation (SCS) is an effective intervention for this condition, but is hampered by the technical challenges associated with precisely directing stimulation to distal extremities. Dorsal root ganglia (DRG) may be more effective as a physiological target for electrical modulation due to recruitment of the primary sensory neurons that innervate the painful distal anatomical regions.

METHODS

Eleven subjects diagnosed with uni- or bilateral lower-extremity CRPS were recruited as part of a larger study involving chronic pain of heterogeneous etiologies. Quadripolar epidural leads of a newly developed neurostimulation system were placed near lumbar DRGs using conventional percutaneous techniques. The neurostimulators were trialed; 8 were successful and permanently implanted and programed to achieve optimal pain-paresthesia overlap.

RESULTS

All 8 subjects experienced some degree of pain relief and subjective improvement in function, as measured by multiple metrics. One month after implantation of the neurostimulator, there was significant reduction in average self-reported pain to 62% relative to baseline values. Pain relief persisted through 12 months in most subjects. In some subjects, edema and trophic skin changes associated with CRPS were also mitigated and function improved. Neuromodulation of the DRG was able to provide excellent pain-paresthesia concordance in locations that are typically hard to target with traditional SCS, and the stimulation reduced the area of pain distributions.

CONCLUSIONS

Neuromodulation of the DRG appears to be a promising option for relieving chronic pain and other symptoms associated with CRPS. The capture of discrete painful areas such as the feet, combined with stable paresthesia intensities independent of body position, suggests this stimulation modality may allow more selective and consistent targeting of painful areas than traditional SCS.

New Therapy for Refractory Chronic Mechanical Low Back Pain-Restorative Neurostimulation to Activate the Lumbar Multifidus: One Year Results of a Prospective Multicenter Clinical Trial

Objectives

The purpose of the international multicenter prospective single arm clinical trial was to evaluate restorative neurostimulation eliciting episodic contraction of the lumbar multifidus for treatment of chronic mechanical low back pain (CMLBP) in patients who have failed conventional therapy and are not candidates for surgery or spinal cord stimulation (SCS).

Materials and Methods

Fifty‐three subjects were implanted with a neurostimulator (ReActiv8, Mainstay Medical Limited, Dublin, Ireland). Leads were positioned bilaterally with electrodes close to the medial branch of the L2 dorsal ramus nerve. The primary outcome measure was low back pain evaluated on a 10‐Point Numerical Rating Scale (NRS). Responders were defined as subjects with an improvement of at least the Minimal Clinically Important Difference (MCID) of ≥2‐point in low back pain NRS without a clinically meaningful increase in LBP medications at 90 days. Secondary outcome measures included Oswestry Disability Index (ODI) and Quality of Life (QoL; EQ‐5D).

Results

For 53 subjects with an average duration of CLBP of 14 years and average NRS of 7 and for whom no other therapies had provided satisfactory pain relief, the responder rate was 58%. The percentage of subjects at 90 days, six months, and one year with ≥MCID improvement in single day NRS was 63%, 61%, and 57%, respectively. Percentage of subjects with ≥MCID improvement in ODI was 52%, 57%, and 60% while those with ≥MCID improvement in EQ‐5D was 88%, 82%, and 81%. There were no unanticipated adverse events (AEs) or serious AEs related to the device, procedure, or therapy. The initial surgical approach led to a risk of lead fracture, which was mitigated by a modification to the surgical approach.

Conclusions

Electrical stimulation to elicit episodic lumbar multifidus contraction is a new treatment option for CMLBP. Results demonstrate clinically important, statistically significant, and lasting improvement in pain, disability, and QoL.

Chronic Low Back Pain: Restoration of Dynamic Stability

OBJECTIVES

Electrical stimulation for multifidus muscle contraction is a novel approach for treating chronic low back pain (CLBP). A multicenter, open-label feasibility study investigated this modality in patients with continuing CLBP despite medical management and no prior back surgery and no known pathological cause of CLBP.

METHODS

Twenty-six patients with continuing CLBP despite physical therapy and medication were implanted with commercially-available implantable pulse generators and leads positioned adjacent to the medial branch of the dorsal ramus as it crosses the L3 transverse process such that electrical stimulation resulted in contraction of the lumbar multifidus (LM) muscle. Patients self-administered stimulation twice daily for 20 min. Low back pain (VAS), Oswestry Disability Index (ODI) and Quality of Life (EQ-5D) scores were collected at three and five months and compared to baseline. Stimulation was withdrawn between months 4 and 5 to test durability of effect.

RESULTS

At three months, 74% of patients met or exceeded the minimally important change (MIC) in VAS and 63% for disability. QoL improved in 84% of patients (N = 19) and none got worse. Five of the 11 patients on disability for CLBP (45%) resumed work by three months. Half the patients reported ≥50% VAS reduction by month 5. Twenty-one lead migration events occurred in 13 patients, of which 7 patients are included in the efficacy cohort.

CONCLUSIONS

Episodic stimulation to induce LM contraction can reduce CLBP and disability, improve quality of life and enable return to work. A dedicated lead design to reduce risk of migration is required.

Durability of the Therapeutic Effect of Restorative Neurostimulation for Refractory Chronic Low Back Pain

Objectives

The purpose of the ongoing follow‐up of ReActiv8‐A clinical trial is to document the longitudinal benefits of episodic stimulation of the dorsal ramus medial branch and consequent contraction of the lumbar multifidus in patients with refractory mechanical chronic low back pain (CLBP). We report the four‐year outcomes of this trial.

Materials and Methods

ReActiv8‐A is a prospective, single‐arm trial performed at nine sites in the United Kingdom, Belgium, and Australia. Eligible patients had disabling CLBP (low back pain Numeric Rating Scale [NRS] ≥6; Oswestry Disability Index [ODI] ≥25), no indications for spine surgery or spinal cord stimulation, and failed conventional management including at least physical therapy and medications for low back pain. Fourteen days postimplantation, stimulation parameters were programmed to elicit strong, smooth contractions of the multifidus, and participants were given instructions to activate the device for 30‐min stimulation‐sessions twice daily. Annual follow‐up through four years included collection of NRS, ODI, and European Quality of Life Score on Five Dimensions (EQ‐5D). Background on mechanisms, trial design, and one‐year outcomes were previously described.

Results

At baseline (N = 53) (mean ± SD) age was 44 ± 10 years; duration of back pain was 14 ± 11 years, NRS was 6.8 ± 0.8, ODI 44.9 ± 10.1, and EQ‐5D 0.434 ± 0.185. Mean improvements from baseline were statistically significant (p < 0.001) and clinically meaningful for all follow‐ups. Patients completing year 4 follow‐up, reported mean (±standard error of the mean) NRS: 3.2 ± 0.4, ODI: 23.0 ± 3.2, and EQ‐5D: 0.721 ± 0.035. Moreover, 73% of participants had a clinically meaningful improvement of ≥2 points on NRS, 76% of ≥10 points on ODI, and 62.5% had a clinically meaningful improvement in both NRS and ODI and 97% were (very) satisfied with treatment.

Conclusions

In participants with disabling intractable CLBP who receive long‐term restorative neurostimulation, treatment satisfaction remains high and improvements in pain, disability, and quality‐of‐life are clinically meaningful and durable through four years.

Randomized controlled trial of patient-controlled epidural analgesia after orthopaedic surgery with sufentanil and ropivacaine 0.165% or levobupivacaine 0.125%

BACKGROUND

Ropivacaine, and to a lesser extent also levobupivacaine, is commonly used for postoperative epidural analgesia. Despite ED50 data suggesting a potency difference between these drugs, clinically they can be difficult to distinguish. As a consequence, it is unclear which concentration of each drug to use when comparing them for long-term analgesia.

METHODS

One hundred patients undergoing total hip or knee replacement were selected to participate in a double-blind randomized study comparing ropivacaine 0.165% with levobupivacaine 0.125% to which was added sufentanil 1 microg ml(-1) for postoperative analgesia by the epidural route. Patient-controlled epidural analgesia (PCEA) was offered for 48 h. After the first 24 h, the basal infusion was omitted.

RESULTS

Pain scores both at rest and on mobilization were similar between both groups. The volume of local anaesthetic solution consumed during the first 48 h after surgery was 25% higher in those patients receiving ropivacaine (P=0.02). Patients receiving ropivacaine made a mean (SD) of 38.5 (16) PCEA demands in the first 48 h after surgery compared with 28 (13) in the levobupivacaine group (P=0.04).

CONCLUSIONS

Both local anaesthetics provided effective postoperative analgesia but, even in a 25% weaker concentration, a small volume of levobupivacaine and opiate substance was consumed. These differences may be explained by a potency difference or by the duration of action of levobupivacaine.

Phenotype of patients responsive to occipital nerve stimulation for refractory head pain

Occipital nerve stimulation (ONS) has been employed off-label for medically refractory head pain. Identification of specific headache diagnoses responding to this modality of treatment is required. Forty-four patients with medically refractory head pain and treated with ONS were invited to participate in a retrospective study including a clinical interview and, if necessary, an indomethacin test to establish the headache phenotype according to the International Classification of Headache Disorders, 2nd edn (ICHD-II). We gathered data from questionnaires before implantation, at 1 month after implantation, and at long-term follow-up. Twenty-six patients consented and were phenotyped. At 1 month follow-up and at long-term follow-up a significant decrease in all pain parameters was noted, as well as in analgesic use. Quality of sleep and quality of life improved. Patient satisfaction was generally high as 80% of patients had ≥ 50% pain relief at long-term follow-up. The overall complication rate was low, but revisions were frequent. After phenotyping, two main groups emerged: eight patients had 'Migraine without aura' (ICHD-II 1.1) and eight patients 'Constant pain caused by compression, irritation or distortion of cranial nerves or upper cervical roots by structural lesions' (ICHD-II 13.12). Overuse of symptomatic acute headache treatments was associated with less favourable long-term outcome in migraine patients. We conclude that careful clinical phenotyping may help in defining subgroups of patients with medically refractory headache that are more likely to respond to ONS. The data suggest medication overuse should be managed appropriately when considering ONS in migraine. A controlled prospective study for ONS in ICHD-II 13.12 is warranted.

Is the Self-Reporting of Failed Back Surgery Syndrome Patients Treated With Spinal Cord Stimulation in Line With Objective Measurements?

OBJECTIVES

To understand the subjective pain experience of patients, healthcare providers rely heavily on self-reporting. However, to quantify this unique pain experience, objective parameters are not yet available in daily clinical practice. With regard to patients with failed back surgery syndrome (FBSS) treated with spinal cord stimulation (SCS), pain therapists may recover the individual functional information about the patient's posture from the implantable pulse generator (IPG) of the stimulator. The aim of this study is to investigate whether subjective self-reporting is in correlation with the functional capacities of a patient.

MATERIALS AND METHODS

Thirty-nine patients with FBSS, treated with SCS were included. The accelerometer in the IPG detects positional changes and provides an objective output of seven functional positions (lying back, lying prone, lying left, lying right, transition, upright, and upright + mobile). The Oswestry Disability Index (ODI), VAS-diary, and the Pittsburgh Sleep Quality Index (PSQI) were assessed to evaluate physical functioning, pain intensities, and subjective sleep quality. Additionally, 21 patients wore a wearable actigraph device to objectify sleep quality. The agreement and Spearman correlations between objective and subjective parameters were assessed.

RESULTS

Spearman rank correlations revealed no significant correlations between the ODI (subscales walking, sitting, standing, and sleeping) and the output of the IPG (percentage upright + mobile, transition, upright, and lying, respectively). Sleep parameters measured with the Actiwatch and the PSQI were not in agreement.

CONCLUSIONS

This study demonstrated that self-reporting questionnaires do not correlate with the findings of objective measurements. Therefore, we recommend using both subjective and objective parameters when determining treatment options for FBSS patients.

Dorsal root ganglion stimulation for patients with refractory pain due to anterior cutaneous nerve entrapment syndrome: A case series

BACKGROUND

Anterior cutaneous nerve entrapment syndrome (ACNES) is a painful condition that can be refractory in a small percentage of patients. Abdominal pain caused by thoracic nerve entrapment in the abdominal wall characterizes ACNES. In the small number of refractory patients to all standard treatments, medication overuse and abuse are serious problems. Dorsal root ganglion (DRG) stimulation might be a good treatment to improve pain scores and to lower medication use.

METHODS

We describe the retrospective analysis of nine cases of patients who underwent DRG stimulation for refractory ACNES using a treatment algorithm. We focused on reported pain intensity scores, medication use, and adverse events.

RESULTS

All nine patients experienced a decrease in pain intensity during the trial period and received a permanent pulse generator implantation. Three months after permanent implantation, eight of nine patients showed a pain reduction of more than 50%. Medication use was substantially lower.

DISCUSSION AND CONCLUSION

This case series shows that DRG stimulation might be a very good treatment for refractory ACNES.

Spinal Cord Stimulation-Naïve Patients vs Patients With Failed Previous Experiences With Standard Spinal Cord Stimulation: Two Distinct Entities or One Population?

INTRODUCTION

Nowadays, the success of spinal cord stimulation (SCS) is evaluated separately in patients who have previous experiences with standard SCS and in SCS-naïve patients. Nevertheless, it is yet to be evaluated whether both patient groups are effectively distinct patient groups. Therefore, the aims of this study are twofold: 1) Are there clusters in the data to distinguish between both patient groups? 2) Can we discriminate both patient groups based on routinely collected clinical parameters?

MATERIALS AND METHODS

Baseline data from the Discover study were used, in which 263 patients with persistent spinal pain syndrome type 2 were included (185 neurostimulation-naïve patients and 78 patients with previous SCS experience). Pain intensity scores for low back and leg pain, functional disability, medication use, and health-related quality of life utility scores were used in the analysis. Model-based clustering was performed on standardized data. Discriminant analysis was performed with linear and quadratic discriminant analysis, with leave-one-out cross-validation to evaluate model performance.

RESULTS

Model-based clustering revealed two different clusters in the data. None of the clusters clearly separated SCS-naïve patients from patients with previous SCS experience. Linear discriminant analysis resulted in a leave-one-out cross-validation error rate of 30.0% to discriminate between both patient groups, based on routinely collected clinical parameters.

CONCLUSIONS

Clustering analysis did not result in clusters that separate SCS-naïve patients from patients with previous SCS experience. This may suggest that both patient groups should not be considered as two different patient groups when comparing them on routine clinical parameters, with potentially profound implications for research and clinical settings.

CLINICAL TRIAL REGISTRATION

The Clinicaltrials.gov registration number for the Discover study is NCT02787265.

Trigeminal neuropathy: Two case reports of gasserian ganglion stimulation

This report describes the successful treatment of two patients with trigeminal neuropathy by using gasserian ganglion stimulation. Case reports: The first case report deals with a 53-year-old woman suffering from right-sided facial pain after a gamma knife lesion for schwannoma of the right inner ear. For 9 years, several interventions with the aim of relieving the pain were unsuccessful; in fact, they had aggravated the symptoms. A trial with a neurostimulator at the level of the Gasser ganglion had an immediately positive effect on her score for facial pain, which decreased from 7.3 to 0 on a visual analog scale, assessed during a period of 2 months. Additionally, the patient had weaned off all her medication by the end of the period. The second case report describes a 64-year-old man suffering from trigeminal neuropathy, which mainly manifested itself as an itch. For a period of 15 years, neither medication nor several interventions were effective. A trial with an electrode at the level of the Gasser ganglion reduced his pain score from 7.0 to 1.5 on a visual analog scale, assessed during a period of three months. His medication could be limited to pregabalin 150 mg bidaily. In contrast, prior to the implantation, his oral medication consisted of pregabalin 75 mg up to five times a day. Conclusion: These case reports show that stimulation of the gasserian ganglion is a successful, minimally invasive, and non-destructive treatment in refractory trigeminal neuropathy and should be considered earlier in the treatment algorithm of trigeminal neuropathy.

High-Frequency Supraorbital Nerve Stimulation With a Novel Wireless Minimally Invasive Device for Post-Traumatic Neuralgia: A Case Report

BACKGROUND

Post-traumatic neuropathic pain in the head and face is a condition that is often refractory to medical management. Peripheral nerve stimulation (PNS) can be an effective treatment. Successful implantation of a novel minimally invasive wireless device is reported here.

OBJECTIVE

To assess analgesic effects of a minimally invasive wireless PNS device in the treatment of post-traumatic supraorbital neuralgia (SON).

CASE SUMMARY

The patient presented with SON following multiple post-traumatic cranioplasty surgeries, which were complicated by infections. Medical and interventional management failed, and the patient reported a numeric rating scale (NRS) pain score of 8 out of 10. Two octopolar implantable neural stimulators (INSs) (StimRelieve LLC, Pompano Beach, FL, U.S.A.) were implanted with a minimally invasive, percutaneous technique to stimulate the supraorbital nerves. Stimulation parameters were set at a frequency of 10 kHz and a pulse width of 30 microseconds.

RESULTS

At 12- and 24-month follow-up evaluations, the patient's NRS score was only 2 out of 10, and the patient occasionally required 1 g of paracetamol to control the pain. Stimulation was reported to be paresthesia free. There were no adverse events related to the procedure or the treatment until today.

CONCLUSIONS

High-frequency stimulation with an external pulse generator and minimally invasive, percutaneous, and bilateral placement of 2 passive INSs on the supraorbital nerves resulted in a significant pain relief in this patient with post-traumatic SON. The device was safe and effective, and the cosmesis was satisfactory.

Detoxification of Neuromodulation Eligible Patients by a Standardized Protocol: A Retrospective Pilot Study

OBJECTIVES

Patients eligible for spinal cord stimulation (SCS) generally experience excruciating pain, requiring more opioid consumption, which is usually an indication for SCS implantation. After final implantation, SCS has the ability to stabilize or decrease opioid usage in half of the patients. In this study, opioids were actively eliminated prior to implantation of any neuromodulation device with a standardized detoxification protocol. This pilot study aims to explore the feasibility, effectiveness, and safety of this opioid detoxification protocol prior to neuromodulation techniques.

MATERIALS AND METHODS

In this retrospective pilot study, 70 patients who were taking opioids and who were eligible for neuromodulation techniques, underwent the detoxification program. A combined in- and out-patient clinic protocol was applied, whereby clonidine was the main component of both parts of the program. A multidisciplinary team with pain physicians and psychologists was responsible for performing this detoxification program. Safety and feasibility were systematically recorded during the hospitalization.

RESULTS

No serious safety issues were reported. At the start of the program, patients reported a mild sedative effect of clonidine. Additionally, most patients presented mild symptoms of opioid withdrawal, which were partially countered by the sedative effect of clonidine. Both patients and the medical staff found this protocol feasible in clinical practice. Concerning the effectiveness, a statistically significant decrease in median morphine milligram equivalents (MMEs) was found with a MME of 175 (Q1-Q3: 118.1-240) at baseline and at the last available follow-up visit the MME was 0 (Q1-Q3: 0-16.88).

CONCLUSIONS

This standardized detoxification program has proven its effectiveness, safety, and feasibility in this single-center experience pilot study in patients eligible for neuromodulation techniques.

European randomized controlled trial evaluating differential target multiplexed spinal cord stimulation and conventional medical management in subjects with persistent back pain ineligible for spine surgery: 24-month results

BACKGROUND

Differential target multiplexed spinal cord stimulation (DTM SCS) was shown to be superior to conventional SCS for treating chronic low back pain (CLBP) in subjects with persistent spinal pain syndrome with previous spinal surgery (PSPS-T2) or ineligible for it (PSPS-T1). This study reports 24-month efficacy and safety of DTM SCS vs. conventional medical management (CMM) in PSPS-T1 subjects across four European countries.

METHODS

This is a prospective, multicenter, open-label, randomized, controlled trial with optional crossover. Subjects randomized 1:1 to DTM SCS or CMM. Primary endpoint was responder rate (% subjects reporting ≥50% CLBP relief) at 6 months. A superiority test compared responder rates between treatments. CLBP and leg pain levels, functional disability, quality of life (QoL), patient satisfaction and global impression of change were evaluated for 24 months. A Composite Responder Index (CRI) was obtained using CLBP relief, disability and QoL. Incidence of study-related adverse events evaluated safety.

RESULTS

A total of 55 and 57 subjects were randomized to DTM SCS and CMM respectively. DTM SCS was superior, with CLBP responder rates ≥80% and CLBP relief >5.6 cm (>70% reduction) through the 24-month follow-up. Improvements with DTM SCS in other outcomes were sustained. The CRI was >80% for DTM SCS through 24 months. Opioid medication intake decreased in subjects treated with DTM SCS. Most patients treated with DTM SCS felt satisfied and improved at the end of the study. Safety was congruent with other studies.

CONCLUSION

DTM SCS is efficacious and safe during 24 months for the treatment of CLBP and leg pain in PSPS-T1 patients ineligible for spine surgery.

SIGNIFICANCE STATEMENT

This randomized controlled trial shows that Differential Target Multiplexed SCS (DTM SCS) is an effective and safe long-term treatment for PSPS type 1 patients suffering from axial low back pain with or without leg pain and who are ineligible for spinal surgery. Currently, CMM treatments are their only option and provide limited benefits. Besides superior pain relief, DTM SCS provides significant improvements in functional disability, quality of life, high levels of satisfaction and perceived impression of change.

Pain, quality of life, and function in chronic intractable leg pain were substantially improved with 10kHz spinal cord stimulation in a multicentre European study

PURPOSE

This prospective, single-arm, multicentre study evaluated the effectiveness of 10 kHz spinal cord stimulation (SCS) in relieving pain and improving function and quality of life in patients with chronic intractable leg pain in routine clinical practice.

METHODS

Patients with leg pain refractory to conservative therapy and scoring ≥ 5 cm on a 10-cm visual analog scale (VAS) were enrolled at 12 centres. Those who achieved ≥ 50% leg pain relief during a temporary trial underwent permanent implantation and were followed for 12 months. Outcomes collected included the proportion of patients who achieved ≥ 50% reduction in leg pain VAS score, health-related quality-of-life (EQ-5D-5 L, functional disability [ODI]), opioid use, sleep quality (PSQ-3), global impression of change (GIC), and patient satisfaction.

RESULTS

Of 121 patients trialed, 118 completed the trial and 95 proceeded to implant. At 3 months, 61/95 (64.2%) of all implanted patients were responders to therapy (≥ 50% VAS reduction), which remained stable at 64.2% through 12 months. EQ-5D-5 L, ODI, and PSQ-3 showed clinically important and sustained improvement over 12 months (repeated measures ANOVA, p < 0.001). Patients also reduced opioid dosage on average (p = 0.022). The safety profile was consistent with previous reports using 10 kHz SCS.

CONCLUSION

This study supports 10 kHz SCS as an effective and safe therapeutic option to reduce pain and disability while improving health-related quality of life in patients with chronic intractable leg pain. 10 kHz SCS appears to be effective in significantly improving the severe disability and poor quality of life experienced by patients with chronic intractable leg pain.

STUDY REGISTERED

ISRCTN Registry - ISRCTN11180496.