Spinal Cord Stimulation Meets Them All: An Effective Treatment for Different Pain Conditions. Our Experience and Literature Review.

IntroductionSpinal Cord Stimulation (SCS) is an emerging minimally invasive technique which uses neuromodulation to manage different forms of intractable pain. SCS is a well-established option for the treatment of various pain conditions, and nowadays, indications are ever increasing.Materials and MethodsIn this study, we present our case series of 49 patients who underwent SCS at our Institution for the treatment of pain from different etiologies, and discuss our 10-year experience in SCS. For the purpose of this study, we also performed a systematic review of current indications and new perspectives in SCS.ResultsAmong our case series, patients were differentiated into two groups upon prior spinal surgery: patients who had undergone prior spinal surgery for back pain were defined as the "FBSS (failed back surgery syndrome) group," instead patient suffering from different types of pain but who had never undergone surgery were defined as the "naive group." As regards clinical response to SCS, 20 patients out of 36 (55.56%) were classified as responders in the FBSS group; in the "naïve" group, 10 patients out of 13 (76.92%) were classified as responders. Among the "not responders" group, several patients suffered from infections.Of the recent literature about SCS, 2124 records were screened and 37 studies were finally included in the qualitative synthesis for our systematic review.DiscussionIn case of FBSS, surgical revision is often associated with a high morbidity and corresponding low rates of success. Unfortunately, patients affected by chronic pain often become refractory to conservative treatments. Spinal Cord Stimulation (SCS) is nowadays considered as an effective therapy for several chronic and neuropathic pain conditions, such as failed back surgery syndrome. As regards the economic impact of SCS, implantation of an SCS system results in short-term costs increase, but the annual cumulative costs decrease during the following years after implantation, when compared to the costs of conventional management. Beyond the application for the treatment of FBSS, SCS has also been used for the treatment of other types of chronic non-oncological pain such as neuropathic pain and chronic back pain ineligible for surgical intervention. This evidence paved the way to establishing the potential role of SCS also for the treatment of oncological pain. However, the effectiveness and relative safety of SCS for cancer-related pain has not yet been adequately established.ConclusionsSpinal Cord Stimulation is a well-established treatment option in for FBSS. Beyond that, SCS has also been used for the treatment of "naive" patients, suffering from other types of chronic, both oncological and non-oncological, medical-refractory pain such as neuropathic pain and chronic back pain ineligible for surgical intervention.

Subcutaneous Stimulation as Add-on Therapy to Spinal Cord Stimulation in Patients With Persistent Spinal Pain 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.

Short-Term Health Care Costs of High-Frequency Spinal Cord Stimulation for the Treatment of Postsurgical Persistent Spinal Pain Syndrome.

OBJECTIVE: High-frequency spinal cord stimulation (HF-SCS) is a treatment option for postsurgical persistent spinal pain syndrome (type 2 PSPS). We aimed to determine the health care costs associated with this therapy in a nationwide cohort. MATERIALS AND METHODS: IBM Marketscan® Research Databases were used to identify patients who underwent HF-SCS implantation from 2016 to 2019. Inclusion criteria included prior spine surgery or diagnoses of PSPS or postlaminectomy pain syndrome any time within the two years before implantation. Inpatient and outpatient service costs, medication costs, and out-of-pocket costs were collected six months before implantation (baseline) and one, three, and six months after implantation. The six-month explant rate was calculated. Costs were compared between baseline and six months after implant via Wilcoxon sign rank test. RESULTS: In total, 332 patients were included. At baseline, patients incurred median total costs of $15,393 (Q1: $9,266, Q3: $26,216), whereas the postimplant median total costs excluding device acquisition were $727 (Q1: $309, Q3: $1,765) at one month, $2,840 (Q1: $1,170, Q3: $6,026) at three months, and $6,380 (Q1: $2,805, Q3: $12,637) at six months. The average total cost was reduced from $21,410 (SD $21,230) from baseline to $14,312 (SD $25,687) at six months after implant for an average reduction of $7,237 (95% CI = $3212-$10,777, p < 0.001). The median device acquisition costs were $42,937 (Q1: $30,102, Q3: $65,880). The explant rate within six months was 3.4% (8/234). CONCLUSIONS: HF-SCS for PSPS was associated with significant decreases in total health care costs and offsets acquisition costs within 2.4 years. With the rising incidence of PSPS, it will be critical to use clinically effective and cost-efficient therapies for treatment.

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

OBJECTIVES: Failed back surgery syndrome (FBSS) is associated with impaired autonomic tone, characterized by sympathetic prevalence and vagal withdrawal. Although spinal cord stimulation (SCS) alleviates pain in FBSS, there is limited research investigating how SCS affects measures of autonomic function. This was a prospective, open-label, feasibility study exploring measures of autonomic function in patients with FBSS receiving SCS therapy. MATERIALS AND METHODS: A total of 14 patients with FBSS were recruited for baseline measurements and underwent a trial of 10-kHz SCS. There were three failed trials, resulting in the remaining 11 participants receiving a fully implanted 10-kHz SCS system. One participant requested an explant, resulting in ten participants completing both baseline and follow-up (three to six months after SCS implant) measurements. Autonomic function was assessed using time- and frequency-domain heart rate variability (HRV), baroreceptor reflex sensitivity (BRS), and muscle sympathetic nerve activity (MSNA) using microneurography. Because this was a feasibility study, most of the analysis was descriptive. However, paired t-tests and Wilcoxon signed-rank tests tested for differences between baseline and follow-up. RESULTS: In the whole (N = 14) and final (N = 10) samples, there was between-participant variation in baseline and follow-up measures. This, combined with a small sample, likely contributed to finding no statistically significant differences in any of the measures between baseline and follow-up. However, plotting baseline and follow-up scores for individual participants revealed that those who showed increases in MSNA frequency, square root of the mean of the squared differences between adjacent RR intervals (RMSSD), percentage of the number of RR intervals >50 ms (pRR50), total power, and up BRS between baseline and follow-up had distinct clustering of baseline values compared with those who showed decreases in these measures. CONCLUSIONS: Findings from this feasibility study will aid with informing hypotheses for future research. A key aspect that should be considered in future research concerns exploring the role of baseline measures of autonomic function in influencing change in autonomic function with SCS therapy.

Long-Term Outcome in Patients With Spinal Cord Stimulation for Failed Back Surgery Syndrome: A 20-Year Audit of a Single Center.

STUDY DESIGN: This is a retrospective, observational study. INTRODUCTION: Spinal cord stimulation (SCS) has found its application in chronic pain treatment, with failed back surgery syndrome (FBSS) as one of the most important indications. However, to date, little is known about the long-term effectiveness of the treatment. The aim of this study is to analyze retrospectively the long-term outcomes of SCS treatment in a single multidisciplinary pain center on predominant radicular pain, using devices of a single manufacturer. MATERIALS AND METHODS: Patient data on overall patient satisfaction, pain intensity, and adverse events were retrospectively collected in our clinical practice between January 1998 and January 2018, for 191 patients who received a permanent SCS implant. Secondary health measures included the influence of opioid and nicotine use on pain reduction after therapy. RESULTS: The trial-to-implant ratio was 93.6%. At a mean follow-up of 10.6 years, 78.5% of the patients were satisfied with the treatment outcome, with a significant pain reduction of an average three points on a Numeric Rating Scale. Opioid and nicotine usage did not have a significant link with the pain reduction one year after the treatment. Furthermore, devices had an average battery lifespan of 8.4 years. A total of 248 revisions were recorded. A total of 24 patients (11.7%) acquired an infection; 7 of 204 patients had an infection during the trial period, 2 of 191 patients had an infection in the first postoperative year, and 15 of 191 patients had an infection after the first year. The average time to infection, if not in the first year, was 10.1 years. CONCLUSIONS: A successful long-term outcome regarding pain relief in patients with predominant radicular pain due to FBSS is established with SCS therapy.

Exceptional Cases of Spinal Cord Stimulation for the Treatment of Refractory Cancer-Related Pain.

OBJECTIVES: Cancer pain has traditionally been managed with opioids, adjuvant medications, and interventions including injections, neural blockade, and intrathecal pump (ITP). Spinal cord stimulation (SCS), although increasingly used for conditions such as failed back surgery syndrome and complex regional pain syndrome, is not currently recommended for cancer pain. However, patients with cancer-related pain have demonstrated benefit with SCS. We sought to better characterize these patients and the benefit of SCS in exceptional cases of refractory pain secondary to progression of disease or evolving treatment-related complications. MATERIALS AND METHODS: This was a single-center, retrospective case series at a tertiary cancer center. Adults ≥18 years old with active cancer and evolving pain secondary to disease progression or treatment, whose symptoms were refractory to systemic opioids, and who underwent SCS trial followed by percutaneous implantation between 2016 and 2021 were included. Descriptive statistics included mean, SD, median, and interquartile range (IQR). RESULTS: Eight patients met the inclusion criteria. The average age at SCS trial was 60.0 (SD: ±11.6) years, and 50% were men. Compared with baseline, the median (IQR) change in pain score by numeric rating scale (NRS) after trial was -3 (2). At an average of 14 days after implant, the median (IQR) change in NRS and daily oral morphine equivalents were -2 (3.5) and -126 mg (1095 mg), respectively. At a median of 63 days after implant, the corresponding values were -3 (0.75) and -96 mg (711 mg). There was no significant change in adjuvant therapies after SCS implantation at follow-up. Six patients were discharged within two days after implantation. Two patients were readmitted for pain control within the follow-up period. CONCLUSIONS: In patients with cancer-related pain, SCS may significantly relieve pain, reduce systemic daily opioid consumption, and potentially decrease hospital length of stay and readmission for pain control. It may be appropriate to consider an SCS trial before ITP in select cases of cancer-related pain.

Functional Connectivity Magnetic Resonance Imaging Sequences in Patients With Postsurgical Persistent Spinal Pain Syndrome Type 2 With Implanted Spinal Cord Stimulation Systems: A Safety, Feasibility, and Validity Study.

BACKGROUND: Chronic pain has been associated with alterations in brain connectivity, both within networks (regional) and between networks (cross-network connectivity). Functional connectivity (FC) data on chronic back pain are limited and based on heterogeneous pain populations. Patients with postsurgical persistent spinal pain syndrome (PSPS) type 2 are good candidates for spinal cord stimulation (SCS) therapy. We hypothesize that 1) FC magnetic resonance imaging (fcMRI) scans can be safely obtained in patients with PSPS type 2 with implanted therapeutic SCS devices and that 2) their cross-network connectivity patterns are altered and involve emotion and reward/aversion functions. MATERIALS AND METHODS: Resting-state (RS) fcMRI (rsfcMRI) scans were obtained from nine patients with PSPS type 2 implanted with therapeutic SCS systems and 13 age-matched controls. Seven RS networks were analyzed, including the striatum. RESULTS: Cross-network FC sequences were safely obtained on a 3T MRI scanner in all nine patients with PSPS type 2 with implanted SCS systems. FC patterns involving emotion/reward brain circuitry were altered as compared with controls. Patients with a history of constant neuropathic pain, experiencing longer therapeutic effects of SCS, had fewer alterations in their connectivity patterns. CONCLUSIONS: To our knowledge, this is the first report of altered cross-network FC involving emotion/reward brain circuitry in a homogeneous population of patients with chronic pain with fully implanted SCS systems, on a 3T MRI scanner. All rsfcMRI studies were safe and well tolerated by all nine patients, with no detectable effects on the implanted devices.

Failed Back Surgery Syndrome: No Longer a Surgeon's Defeat-A Narrative Review.

The introduction of the term Persistent Spinal Pain Syndrome (PSPS-T1/2), replacing the older term Failed Back Surgery Syndrome (FBSS), has significantly influenced our approach to diagnosing and treating post-surgical spinal pain. This comprehensive review discusses this change and its effects on patient care. Various diagnostic methods are employed to elucidate the underlying causes of back pain, and this information is critical in guiding treatment decisions. The management of PSPS-T1/2 involves both causative treatments, which directly address the root cause of pain, and symptomatic treatments, which focus on managing the symptoms of pain and improving overall function. The importance of a multidisciplinary and holistic approach is emphasized in the treatment of PSPS-T1/2. This approach is patient-centered and treatment plans are customized to individual patient needs and circumstances. The review concludes with a reflection on the impact of the new PSPS nomenclature on the perception and management of post-surgical spinal pain.

Spinal cord stimulation and return to work of patients with failed back surgery syndrome.

OBJECTIVES: Chronic pain has a substantial negative impact on work-related outcomes, which underlines the importance of interventions to reduce the burden. Spinal cord stimulation (SCS) efficiently relieves pain in specific chronic pain syndromes and is recommended for treating failed back surgery syndrome (FBSS) or post-surgical chronic back pain that is refractory to other treatments. To examine the impact of SCS in patients with FBSS on the return to work (RTW), we determined the RTW rate and the factors positively associated with the RTW. MATERIALS AND METHODS: Among 106 patients with FBSS who benefitted from SCS at a single institution in France between September 1999 and March 2010, we retrospectively included 59 who had stopped work at the time of SCS because of disability or sick leave and evaluated the RTW (rate and predictors, estimating odds ratios [ORs] and 95% confidence intervals [CIs]). RESULTS: The mean (SD) post-surgery follow-up for the 59 patients (34 men; mean [SD] age 46.9 [7.4] years) was 7.5 (3.6) years (range 5-15). The RTW rate was 30.5%, with a median [IQR] recovery time of 5.5 months [3-8.5]. RTW was improved with functional improvement evolution (OR 1.1, 95% CI [1.01-1.1], p = 0.02) and was reduced with unemployment > 3 years (OR 0.1, 95% CI [0.01-0.7], p = 0.02). CONCLUSIONS: Our protocol for SCS for patients with FBSS, including a strict selection of patients and a multidisciplinary approach, led to good results, especially for the RTW. RTW should be a therapeutic goal, directly affecting indirect costs related to FBSS.

Effect of Spinal Cord Burst Stimulation vs Placebo Stimulation on Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery: A Randomized Clinical Trial.

Importance: The use of spinal cord stimulation for chronic pain after lumbar spine surgery is increasing, yet rigorous evidence of its efficacy is lacking. Objective: To investigate the efficacy of spinal cord burst stimulation, which involves the placement of an implantable pulse generator connected to electrodes with leads that travel into the epidural space posterior to the spinal cord dorsal columns, in patients with chronic radiculopathy after surgery for degenerative lumbar spine disorders. Design, Setting, and Participants: This placebo-controlled, crossover, randomized clinical trial in 50 patients was conducted at St Olavs University Hospital in Norway, with study enrollment from September 5, 2018, through April 28, 2021. The date of final follow-up was May 20, 2022. Interventions: Patients underwent two 3-month periods with spinal cord burst stimulation and two 3-month periods with placebo stimulation in a randomized order. Burst stimulation consisted of closely spaced, high-frequency electrical stimuli delivered to the spinal cord. The stimulus consisted of a 40-Hz burst mode of constant-current stimuli with 4 spikes per burst and an amplitude corresponding to 50% to 70% of the paresthesia perception threshold. Main Outcomes and Measures: The primary outcome was difference in change from baseline in the self-reported Oswestry Disability Index (ODI; range, 0 points [no disability] to 100 points [maximum disability]; the minimal clinically important difference was 10 points) score between periods with burst stimulation and placebo stimulation. The secondary outcomes were leg and back pain, quality of life, physical activity levels, and adverse events. Results: Among 50 patients who were randomized (mean age, 52.2 [SD, 9.9] years; 27 [54%] were women), 47 (94%) had at least 1 follow-up ODI score and 42 (84%) completed all stimulation randomization periods and ODI measurements. The mean ODI score at baseline was 44.7 points and the mean changes in ODI score were -10.6 points for the burst stimulation periods and -9.3 points for the placebo stimulation periods, resulting in a mean between-group difference of -1.3 points (95% CI, -3.9 to 1.3 points; P = .32). None of the prespecified secondary outcomes showed a significant difference. Nine patients (18%) experienced adverse events, including 4 (8%) who required surgical revision of the implanted system. Conclusions and Relevance: Among patients with chronic radicular pain after lumbar spine surgery, spinal cord burst stimulation, compared with placebo stimulation, after placement of a spinal cord stimulator resulted in no significant difference in the change from baseline in self-reported back pain-related disability. Trial Registration: ClinicalTrials.gov Identifier: NCT03546738.

The Link Between Spinal Cord Stimulation and the Parasympathetic Nervous System in Patients With Failed Back Surgery Syndrome.

OBJECTIVES: In patients with chronic pain, a relative lower parasympathetic activity is suggested based on heart rate variability measurements. It is hypothesized that spinal cord stimulation (SCS) is able to influence the autonomic nervous system. The aim of this study is to further explore the influence of SCS on the autonomic nervous system by evaluating whether SCS is able to influence skin conductance, blood volume pulse, heart rate, and respiration rate. MATERIALS AND METHODS: Twenty-eight patients with Failed Back Surgery Syndrome (FBSS), who are being treated with SCS, took part in this multicenter study. Skin conductance and cardiorespiratory parameters (blood volume pulse, heart rate, and respiration rate) were measured during on and off states of SCS. Paired statistics were performed on a 5-min recording segment for all parameters. RESULTS: SCS significantly decreased back and leg pain intensity scores in patients with FBSS. Skin conductance level and blood volume pulse were not altered between on and off states of SCS. Heart rate and respiration rate significantly decreased when SCS was activated. CONCLUSIONS: Parameters that are regulated by the sympathetic nervous system were not significantly different between SCS on and off states, leading to the hypothesis that SCS is capable of restoring the dysregulation of the autonomic nervous system by primarily increasing the activity of the parasympathetic system in patients with FBSS.

Surgical Paddle Electrode Implantation as a Rescue Therapy to Failed Percutaneous Leads in Failed Back Surgery Syndrome Patients.

INTRODUCTION: Spinal cord stimulation (SCS) to treat failed back surgery syndrome (FBSS) can be provided with either percutaneously or surgically implanted electrodes. Percutaneous electrodes are considered the first choice in many pain practices, but surgical paddle electrodes can also be indicated if a percutaneous electrode fails to retain sufficient pain relief or if percutaneous implantation is considered unachievable. Although the current efficacy of surgical paddle electrodes has been based mainly upon pain intensity scores, the evidence on surgical paddle electrodes as a rescue to failed percutaneous electrodes remains even more scarce. OBJECTIVE: This study aimed to evaluate the safety and clinical effectiveness of rescue surgical paddle electrodes in FBSS patients, multidimensionally. MATERIALS AND METHODS: The occurrence of complications, pain intensity scores, psychosocial-related questionnaires, and medication intake were collected. Subsequently, a Quality-of-Life Index (QLI) was calculated. A clinically relevant effect was obtained if the minimal clinically important difference regarding pain intensity was reached. RESULTS: A total of 25 patients were included in the study. The pain intensity scores were significantly reduced (p < 0.001), and clinically relevant reductions occurred during short-term (0-6 months), mid-term (1-3 years), and long-term follow-up (≥4 years). The structural morphine usage and QLI were significantly decreased at short-term follow-up (p = 0.038 and p = 0.036, respectively). Six complications occurred in five patients, of which, four concerned hardware-related problems and two were of biological origin. CONCLUSION: SCS utilizing a surgical paddle electrode as a salvage treatment to failed conventional percutaneous cylindrical lead SCS can be practiced safely and effectively to treat FBSS. Because of potentially improved clinical effectiveness and cost-effectiveness resulting from fewer reoperations, a SCS treatment algorithm may benefit from expediting surgical paddle electrodes.

Spinal Cord Stimulation in Failed Back Surgery Syndrome: An Integrative Review of Quantitative and Qualitative Studies.

BACKGROUND: Spinal cord stimulation (SCS) is an established therapy of failed back surgery syndrome (FBSS), although the effects on daily functioning, quality of life (QoL), and patients' expectations, experiences, and satisfaction remain elusive. The current integrative review aimed to summarize the overall effects of SCS in patients with FBSS on pain relief, health-related QoL, and daily activities. MATERIALS AND METHODS: PubMed, CINAHL, Embase, ClinicalTrials.gov, gray literature, and reference lists of relevant articles were searched for additional papers. All included studies were assessed for risk of bias using the Mixed Methods Appraisal Tool. Following the methods of Whittemore and Knafl, an integrative review and a meta-analysis were performed. RESULTS: In total, 16 articles were included; 11 articles presented quantitative outcomes, and five articles presented qualitative data. Lower back pain, leg pain, overall pain, Oswestry Disability Index, EuroQol Five Dimensions Health Questionnaire three-level/five-level, and the physical component score of Short Form Health Survey (SF-36) significantly improved during all follow-up moments. Only the mental component score of the SF-36 did not significantly improve, compared with baseline. Heterogeneity was diversely present among the studies. Patients' expectations and goals were disparate, although patients seemed to desire a return to their pre-FBSS state. Experiences with regard to the outcomes showed that patients largely recuperated after SCS, although limitations were still present. Patients also expressed inconvenience with regard to the trial period, implantation location, and recharging of the implantable pulse generator. CONCLUSIONS: SCS showed beneficial effects on different domains of life in patients with FBSS. The quantitative analyses suggest an overall improvement in most domains, although patients' experiences show that limitations in daily life and living with the SCS system persist. Multiple extensive preoperative counseling sessions and discussions with patients are deemed necessary to improve patient satisfaction and meet their expectations. Shared decision-making and provision of complete information are key factors for success.

Feasibility of continuous epidural analgesia in patients with failed back surgery syndrome and spinal stenosis.

PURPOSE: The purpose of this study was to outline the feasibility of continuous epidural analgesia in the treatment of failed back surgery syndrome (FBSS) or spinal stenosis. METHODS: We queried our prospective collected institutional database to include all consecutive patients, who underwent continuous epidural analgesia with accompanying intensive physiotherapeutic exercise within a timeframe of 4 years. Patients suffered from FBSS or spinal stenosis; protocolled continuous epidural analgesia was planned for 4 days within the framework of an inpatient multimodal pain therapy concept. The instillation technique of the epidural catheter, the capability to attend in accompanying physiotherapy, and the peri-interventional complications were evaluated. RESULTS: 153 patients with an average age of 57.4 years (± 11.9) were enrolled in this study. 105 patients suffered from FBSS and 48 patients had spinal stenosis. Overall, 148 patients (96.7%) reported the pain reduction and were able to perform daily intensified physiotherapeutic exercise. There were no serious adverse events, neither infection nor bleeding, no cardiopulmonary complication or permanent neurological deficits. The most common side effect was neurological impairment, such as numbness, dysesthesia, or weakness of the lower limbs with complete regression after flow rate adjustment. Patients with FBSS were more likely to develop dysesthesia (p = 0.007). CONCLUSIONS: Continuous epidural analgesia is feasible in patients with FBSS or spinal stenosis. This treatment enables extensive physiotherapeutic treatment even in patients with severe pain conditions and can be considered as an alternative to epidural injections. An increased complication rate in comparison to short-term perioperative or perinatal application was not observed.

The Added Value of Intraoperative Hypnosis during Spinal Cord Stimulation Lead Implantation under Awake Anesthesia in Patients Presenting with Refractory Chronic Pain.

To improve pain relief for refractory pain condition, spinal cord stimulation (SCS) needs to target the dedicated neuronal fibers within the dorsal columns. Intraoperative feedback from the patient can optimize lead placement but requires "awake surgery", allowing interaction between patient and surgeon. This can produce negative effects like anxiety and stress. To better manage these aspects, we propose to combine intraoperative hypnosis with awake anesthesia. Seventy-four patients (35 females, 22-80 years) presenting with chronic refractory pain, were offered intraoperative hypnosis during awake SCS lead implantation. Interactive conversational hypnosis was used as well as interactive touch, which was enhanced during painful moments during the lead intraoperative programming. All patients participated actively during the intraoperative testing which helped to optimize the lead positioning. They kept an extremely positive memory of the surgery and of the hypnotic experience, despite some painful moments. Pain could be reduced in these patients by using interactions and touch, which works on Gate Control modulation. Positive memory was reinforced by congratulations to create self-confidence and to induce positive expectations, which could reinforce the Diffuse Noxious Inhibitory Controls at the spinal level. Cooperation was improved because the patient was actively participating and thus, much more alert when feedback was required. Combining intraoperative hypnosis with awake anesthesia appears helpful for SCS lead implantation. It enhances patient cooperation, allows optimization of lead positioning, and leads to better pain control, positive and resourceful memory.

High-frequency spinal cord stimulation in failed back surgery syndrome patients with predominant low back pain-single-center experience.

Treatment of patients with failed back surgery syndrome (FBSS) with predominant low back pain (LBP) remains challenging. High-frequency spinal cord stimulation (HF10 SCS) is believed to achieve significant pain reduction. We aimed to evaluate the real-life efficacy of HF-10 SCS in a tertiary spine center. A prospective observational study of all patients with FBSS and predominant LBP who underwent HF-10 SCS surgery was performed between 2016 and 2018. Patients > 18 years with Visual Analogue Scale (VAS) scores of ≥ 5 for LBP and pain duration > 6 months under stable medication were implanted percutaneous under general anesthesia and a trial phase of 7-14 days was accomplished. Primary end point was a successful trial defined as ≥ 50% VAS score reduction for LBP. Thirty-four of 39 (85%) subjects had a successful trial. Fifty-three percent were female and the mean age was 69 years. Median follow-up lasted for 10 months. Devices were removed after a median of 10 months in 5 cases. Remaining 29 patients stated significant VAS score reduction for LBP from 8.1 to 2.9 and VAS for leg pain from 4.9 to 2.2. Twenty-four percent of all patients were able to discontinue their opioids. Eight of 9 patients (89%) with signs of adjacent disc disease and 7 of 10 (70%) patients with hardware failure were successfully implanted with significant VAS reduction for LBP. HF-10 SCS achieves significant pain reduction in most patients with FBSS and predominant LBP. It might be an efficient alternative to revision surgery.

Experiences From the Patient Perspective on Spinal Cord Stimulation for Failed Back Surgery Syndrome: A Qualitatively Driven Mixed Method Analysis.

INTRODUCTION: When neither pharmacological therapies nor alternative interventions provide sufficient pain relief, spinal cord stimulation (SCS) can be used to treat Failed Back Surgery Syndrome (FBSS). Although it seems reasonable that quality of life (QoL)- and psychosocial-related factors contribute to the outcome of SCS since pain is a multidimensional experience, few qualitative studies have explored the expectations of SCS and experiences on SCS to treat FBSS from the patient perspective. OBJECTIVES: The aim of this study was to qualitatively and quantitatively map the FBSS patients' experiences with SCS and the effects of SCS on low back pain caused by FBSS. MATERIALS AND METHODS: A qualitative study with in-depth semi-structured interviews, assisted by the Brief Pain Inventory (BPI)-questionnaire. RESULTS: Seven themes regarding patients' experiences, subdivided into 15 categories, were identified, including an understudied theme within this field of research, Spiritual Well-Being. "Acceptance" and "coping" emerged as pre-eminent motifs throughout these themes. Moreover, the realization of patients' expectations were variable throughout the presented themes. According to the BPI Questionnaire, four out of 13 patients (31%) had significant pain relief (≥50%). Seven out of 13 (54%) reported a ≥50% increase regarding enjoyment of life. CONCLUSION: Multiple QoL- and psychosocial-related themes are related to SCS-outcomes. In order to improve SCS-outcomes for both short- and long-term, these themes should be implemented as a multidimensional approach, both prior to implantation as during follow-up.

The Long-Term Response to High-Dose Spinal Cord Stimulation in Patients With Failed Back Surgery Syndrome After Conversion From Standard Spinal Cord Stimulation: An Effectiveness and Prediction Study.

OBJECTIVES: Spinal cord stimulation (SCS) is nowadays available with several stimulation paradigms. New paradigms, such as high dose (HD-)SCS, have shown the possibility to salvage patients who lost their initial pain relief. The first aim of this study is to evaluate the effectiveness of HD-SCS after conversion from standard SCS. The second aim is to develop a model for prediction of long-term response of HD-SCS after unsatisfactory standard SCS. MATERIALS AND METHODS: Seventy-eight patients with failed back surgery syndrome (FBSS) who are treated with standard SCS were enrolled in the study. Self-reporting questionnaires and outcomes were assessed before conversion and at 1, 3, and 12 months of HD-SCS. Longitudinal mixed models were used to determine the effectiveness of HD-SCS. Logistic regression and classification and decision tree analyses were performed to predict responders (NRS decrease ≥2/10) after 12 months of HD-SCS. RESULTS: Significant time effects were found for both low back and leg pain responders, suggesting the effectiveness of HD-SCS after conversion. Logistic regression models revealed the importance of pain intensity scores, medication use, paresthesia coverage (for back pain) and EQ5D (for leg pain) as predictors for being a responder after 12 months of HD-SCS. CONCLUSIONS: Converting patients with unsatisfactory responses from standard SCS to HD-SCS may be an effective strategy to obtain and maintain pain relief in a challenging subgroup of patients with FBSS refractory to standard SCS. The prediction models may guide clinicians in their decision making when considering conversion to HD-SCS in patients with FBSS experiencing inadequate response to standard SCS.

Resource Use and Cost of Subcutaneous Nerve Stimulation Versus Optimized Medical Management in Patients With Failed Back Surgery Syndrome: An Analysis of the SubQStim Study.

OBJECTIVES: To undertake a detailed healthcare resource use and cost analysis of the SubQStim study, which randomized patients with failed back surgery syndrome (FBSS) with low back pain to receive subcutaneous nerve field stimulation in combination with optimized medical management (treatment) or optimized medical management alone (control). MATERIALS AND METHODS: Patient-level data from the SubQStim study were used to present descriptive analyses of healthcare resource use and estimated costs for pain medication, healthcare visits, adverse events, and device acquisition/implantation. A United Kingdom National Health Service perspective was adopted, using cost data from national tariffs, drug and device prices, and social care cost studies. Results were calculated as the mean cost per patient over the nine-month follow-up period. RESULTS: Mean cost per patient was £18,403 in the treatment group versus £1613 in the control group. Almost 90% of the cost in the treatment group consisted of device acquisition/implantation. Higher adverse event costs were observed for patients in the treatment group, but lower costs were observed for pain medication and healthcare visits. Over nine months, opioid use decreased in the treatment group and increased in the control group. Enrolment and follow-up were terminated early in the clinical study, leading to substantial between-patient variability in each cost category. CONCLUSIONS: Subcutaneous nerve field stimulation has the potential to offset the initial costs of the device by reducing analgesic medication and the number of healthcare visits in FBSS patients, alongside potential gains in health-related quality of life. There remains uncertainty in long-term costs and cost-effectiveness of stimulation and longer-term follow-up analyses are needed.

Effects of Spinal Cord Stimulation on Heart Rate Variability in Patients With Failed Back Surgery Syndrome: Comparison Between a 2-lead ECG and a Wearable Device.

OBJECTIVES: Heart rate variability recordings have the potential to examine the role of the autonomic nervous system. Several wearable devices are nowadays readily available. Up until now, no studies explored whether a wearable device is able to reliably measure a treatment response in chronic pain patients. Therefore, the aim of this study is to evaluate the reliability of a Polar V800 (Polar Electro Oy, Finland) wearable device to accurately measure RR intervals in patients with failed back surgery syndrome (FBSS) during spinal cord stimulation (SCS), as compared with an eMotion 2-lead ECG recording. MATERIALS AND METHODS: Twenty-two patients diagnosed with FBSS and treated with SCS participated in this study. HRV was measured with a 2-lead ECG registration tool and a Polar V800 during on and off state of SCS. Intraclass correlation coefficients, correlations, limits of agreement, Cronbach's α, and effect sizes were calculated. RESULTS: Analysis based on the recordings from the ECG and wearable device revealed the same HRV parameters (except for the time-frequency domain) to capture the treatment response of SCS. Parameters that are relevant for measuring the SCS treatment response have strong correlations (r ≥ .82), good ICC values (ICC ≥0.82), acceptable consistency (α ≥ .9), and limited bias. CONCLUSIONS: Similar pre- to posttreatment changes were revealed between a wearable device and 2-lead ECG with reliable HRV estimates for parameters that are able to capture the treatment changes. This suggests that a wearable heart rate monitor might be a reliable wearable tool for the detection of pre- to post treatment changes of SCS, in patients with FBSS.