Analysis of spinal canal diameter in the placement of thoracic spinal cord stimulator paddle leads.

BACKGROUND: Neurologic deficit is known as a rare complication of thoracic spinal cord stimulator (SCS) paddle lead implantation, but many believe its incidence after SCS paddle lead placement is under-reported. It is possible that imaging characteristics may be used to help predict safe paddle lead placement. OBJECTIVE: This imaging study was undertaken to determine the minimum canal diameter required for safe paddle lead placement. METHODS: Patients who underwent thoracic laminotomy for new SCS paddle lead placement from January 2018 to March 2023 were identified retrospectively. Preoperative thoracic canal diameter was measured in the sagittal plane perpendicular to the disc space from T5/6 to T11/12. These thoracic levels were chosen because they span the most common levels targeted for SCS placement. Patients with and without new neurologic deficits were compared using a Mann-Whitney U-test. RESULTS: Of 185 patients initially identified, 180 had thoracic imaging available for review. One (0.5%) and 2 (1.1%) of 185 patients complained of permanent and transient neurologic deficit after thoracic SCS placement, respectively. Patients with neurologic deficits had average canal diameters of <11 mm. The average canal diameter of patients with and without neurologic deficits was 10.2 mm (range 6.1-12.9 mm) and 13.0 mm (range 5.9-20.2), respectively (p < 0.0001). CONCLUSION: Postoperative neurologic deficit is an uncommon complication after thoracic laminotomy for SCS paddle lead placement. The authors recommend ensuring a starting thoracic canal diameter of at least 12 mm to accommodate a SCS paddle lead measuring 2 mm thick to ensure a final diameter of >10 mm. If canal diameter is <12 mm, aggressive undercutting of the lamina, a second laminotomy, or placement of smaller SCS wire leads should be considered.

Durable multimodal and holistic response for physiologic closed-loop spinal cord stimulation supported by objective evidence from the EVOKE double-blind randomized controlled trial.

INTRODUCTION: Chronic pain patients may experience impairments in multiple health-related domains. The design and interpretation of clinical trials of chronic pain interventions, however, remains primarily focused on treatment effects on pain intensity. This study investigates a novel, multidimensional holistic treatment response to evoked compound action potential-controlled closed-loop versus open-loop spinal cord stimulation as well as the degree of neural activation that produced that treatment response. METHODS: Outcome data for pain intensity, physical function, health-related quality of life, sleep quality and emotional function were derived from individual patient level data from the EVOKE multicenter, participant, investigator, and outcome assessor-blinded, parallel-arm randomized controlled trial with 24 month follow-up. Evaluation of holistic treatment response considered whether the baseline score was worse than normative values and whether minimal clinical important differences were reached in each of the domains that were impaired at baseline. A cumulative responder score was calculated to reflect the total minimal clinical important differences accumulated across all domains. Objective neurophysiological data, including spinal cord activation were measured. RESULTS: Patients were randomized to closed-loop (n=67) or open-loop (n=67). A greater proportion of patients with closed-loop spinal cord stimulation (49.3% vs 26.9%) were holistic responders at 24-month follow-up, with at least one minimal clinical important difference in all impaired domains (absolute risk difference: 22.4%, 95% CI 6.4% to 38.4%, p=0.012). The cumulative responder score was significantly greater for closed-loop patients at all time points and resulted in the achievement of more than three additional minimal clinical important differences at 24-month follow-up (mean difference 3.4, 95% CI 1.3 to 5.5, p=0.002). Neural activation was three times more accurate in closed-loop spinal cord stimulation (p<0.001 at all time points). CONCLUSION: The results of this study suggest that closed-loop spinal cord stimulation can provide sustained clinically meaningful improvements in multiple domains and provide holistic improvement in the long-term for patients with chronic refractory pain. TRIAL REGISTRATION NUMBER: NCT02924129.

Case report: Dorsal root ganglion stimulator lead fracture.

BACKGROUND: One of the unique advances in neuromodulation for chronic pain has been spinal cord stimulators (SCS) and dorsal root ganglion stimulators (DRG-S). These devices have aided in conditions such as neuropathic pain, complex regional pain syndromes, failed back surgery, and peripheral neuropathies. With these benefits, however, complications from implantable stimulators have included lead fractures and migration. The authors reviewed a lead migration, kinking, and subsequent fracture event involving a patient with complex regional pain syndrome (CRPS) II, who was treated with a DRG-S. CASE PRESENTATION: The case report follows this patient, from their past medical history to assessment of appropriate qualifications for neuromodulation, to successful surgical placement, to follow-up care. The authors further monitored assessment of inefficacy of pain relief, and identification of lead migration and kinking through imaging. In the process of removal, due to lead stress, lead fracturing occurred. After lead removal, the leads were fully replaced, and the patient was followed up and experienced improved pain relief. CONCLUSION: The case report assesses probable mechanisms of lead fracture and considerations for physicians for future assessment and triage of neuromodulation efficacy.

Should we Oppose or Combine Waveforms for Spinal Cord Stimulation in PSPS-T2 Patients? A Prospective Randomized Crossover Trial (MULTIWAVE Study).

Refractory persistent spinal pain syndrome after surgery (PSPS-T2) can be successfully addressed by spinal cord stimulation (SCS). While conventional stimulation generates paresthesia, recent systems enable the delivery of paresthesia-free stimulation. Studies have claimed non-inferiority/superiority of selected paresthesia-free stimulation compared with paresthesia-based stimulation, but the comparative efficacy between different waveforms still needs to be determined in a given patient. We designed a randomized controlled 3-month crossover trial to compare pain relief of paresthesia-based stimulation versus high frequency versus burst in 28 PSPS-T2 patients implanted with multiwave SCS systems. Our secondary objectives were to determine the efficacy of these 3 waveforms on pain surface, quality of life, functional capacity, psychological distress, and validated composite multidimensional clinical response index to provide holistic comparisons at 3-, 6-, 9-, and 15-month post-randomization. The preferred stimulation modality was documented during the follow-up periods. No difference between the waveforms was observed in this study (P = .08). SCS led to significant pain relief, quality of life improvement, improvement of multidimensional clinical response index, and of all other clinical outcomes at all follow-up visits. Forty-four percent of the patients chose to keep the paresthesia-based stimulation modality after the 15-month follow-up period. By giving the possibility to switch and/or to combine several waveforms, the overall rate of SCS responders further increased with 25%. In this study, high frequency or burst do not appear superior to paresthesia-based stimulation, wherefore paresthesia-based stimulation should still be considered as a valid option. However, combining paresthesia-based stimulation with paresthesia-free stimulation, through personalized multiwave therapy, might significantly improve SCS responses. PERSPECTIVE: This article assesses clinical SCS efficacy on pain relief, by comparing paresthesia-based stimulation and paresthesia-free stimulation (including high frequency and burst) modalities in patient presenting with PSPS-T2. Switching and/or combining waveforms contribute to increasing the global SCS responders rate.

Novel implantation technique for pudendal nerve peripheral nerve stimulation for treatment of chronic pelvic pain.

BACKGROUND: Chronic pelvic pain (CPP) is a pervasive, difficult to treat condition affecting up to 26% of the global female and 8.2% of the global male population. Considered a form of chronic regional pain syndrome (CRPS), it is medically complex and often refractory to multimodal management. Neuromodulation has become increasingly popular in treatment of chronic neuropathic pain conditions, including CPP and CRPS. Dorsal column spinal cord stimulation and dorsal root ganglion stimulation have had some success for managing CPP meanwhile peripheral nerve stimulators (PNS) have been suggested as another viable option. However, few studies in the literature have reported successful use of PNS in treatment of CPP. Here, we detail a possible technique for pudendal PNS lead placement for management of CPP. METHOD: This article describes a novel cephalad to caudad fluoroscopic guided technique for pudendal nerve PNS lead placement and implantation. RESULTS: A cephalad to caudal-medial fluoroscopic guided approach as described within to successfully implant a percutaneous pudendal nerve PNS for management of CPP. CONCLUSIONS: The pudendal nerve PNS lead placement technique noted within can be used to avoid many of the important neurovascular structures near the pelvic outlet. Further studies are needed to validate the safety and efficacy of this therapy modality but it may be a viable management option for patients with medically refractory CPP.

Six-Month Follow-up of a Trial of Spinal Cord Burst Stimulation vs Placebo Stimulation and Disability in Patients With Chronic Radicular Pain After Lumbar Spine Surgery.

This follow-up study examines back pain­related disability at 6 months following a randomized trial of spinal cord burst stimulation for chronic radicular pain after lumbar spine surgery.

Holistic Treatment Response: An International Expert Panel Definition and Criteria for a New Paradigm in the Assessment of Clinical Outcomes of Spinal Cord Stimulation.

BACKGROUND: Treatment response to spinal cord stimulation (SCS) is focused on the magnitude of effects on pain intensity. However, chronic pain is a multidimensional condition that may affect individuals in different ways and as such it seems reductionist to evaluate treatment response based solely on a unidimensional measure such as pain intensity. AIM: The aim of this article is to add to a framework started by IMMPACT for assessing the wider health impact of treatment with SCS for people with chronic pain, a "holistic treatment response". DISCUSSION: Several aspects need consideration in the assessment of a holistic treatment response. SCS device data and how it relates to patient outcomes, is essential to improve the understanding of the different types of SCS, improve patient selection, long-term clinical outcomes, and reproducibility of findings. The outcomes to include in the evaluation of a holistic treatment response need to consider clinical relevance for patients and clinicians. Assessment of the holistic response combines two key concepts of patient assessment: (1) patients level of baseline (pre-treatment) unmet need across a range of health domains; (2) demonstration of patient-relevant improvements in these health domains with treatment. The minimal clinical important difference (MCID) is an established approach to reflect changes after a clinical intervention that are meaningful for the patient and can be used to identify treatment response to each individual domain. A holistic treatment response needs to account for MCIDs in all domains of importance for which the patient presents dysfunctional scores pre-treatment. The number of domains included in a holistic treatment response may vary and should be considered on an individual basis. Physiologic confirmation of therapy delivery and utilisation should be included as part of the evaluation of a holistic treatment response and is essential to advance the field of SCS and increase transparency and reproducibility of the findings.

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.

Gradation of Clinical Holistic Response as New Composite Outcome to Evaluate Success in Spinal Cord Stimulation Studies for Pain.

INTRODUCTION: The most prominent outcome measurement in the field of neuromodulation is pain relief. Nevertheless, the number of studies that rely on composite outcomes has increased. The aims of this study are twofold: (1) to evaluate which measures are important to include in a composite outcome and (2) to develop this new composite outcome to evaluate the degree of being a clinical holistic responder with a corresponding minimal clinical important difference (MCID). MATERIALS AND METHODS: Data from patients with persistent spinal pain syndrome type 2 treated with High-Dose Spinal Cord Stimulation (HD-SCS) were used. Pain intensity for low back and leg pain, disability, health-related quality of life, medication use, and patient satisfaction were measured at baseline and after 12 months of HD-SCS. Exploratory and Confirmatory Factor Analyses were used to evaluate which measures should be included in the composite outcome. Anchor-based and distribution-based methods were applied to determine the MCID of the newly developed outcome measurement. RESULTS: A three-factor model was the most appropriate for this data set, in which leg pain intensity, EQ5D VAS, and disability had the largest loading on these factors. A clinical holistic outcome was created with a total score ranging from 0 (=better [no pain, no disability, and perfect health status]) to 300 (=worse [maximal pain, maximal disability, and worst health status]). The MCID value based on an absolute change score from baseline up to 12 months of HD-SCS was 87.97. When calculating with percentage changes, a MCID value of 48.4% was revealed. CONCLUSIONS: This new composite outcome evaluating the degree of deviation from being a holistic responder is a step toward a meaningful, overall outcome assessment for patients who are treated with SCS. Further studies to evaluate the psychometric properties and the generalizability toward other patient populations still need to be performed.

Painful Diabetic Neuropathy - Spinal Cord Stimulation, Peripheral Nerve Stimulation, Transcutaneous Electrical Nerve Stimulation, and Scrambler Therapy: A Narrative Review.

BACKGROUND: First-line medications for the treatment of painful diabetic neuropathy (PDN) are associated with a substantial rate of discontinuation due to adverse effects or insufficient efficacy. Neuromodulation techniques have been used for PDN, but a comprehensive review of the literature that incorporates several distinct device categories has yet to be undertaken. OBJECTIVES: We aimed to summarize the evidence regarding 4 major types of neuromodulation devices for the treatment of PDN. We focused on spinal cord stimulators (SCS), peripheral nerve stimulators (PNS), transcutaneous electrical nerve stimulators (TENS), and scrambler therapy devices (ST) because they are often used for refractory neuropathic pain. STUDY DESIGN: Narrative Review. METHODS: A comprehensive and reproducible literature search was performed using PubMed with no search restrictions applied. The available Medical Subject Headings were used. Inclusion criteria included prospective studies, retrospective studies, case series, and case reports indexed from database inception to the search date (September 14, 2021). RESULTS: Seventeen studies met inclusion criteria, 10 of which were regarding SCS. Only 3 of the 10 were randomized controlled trials. We found no studies assessing contemporary PNS. Four studies assessed TENS, but the devices varied widely in voltages and waveforms. Two case reports described ST. LIMITATIONS: Potential selection bias due to the nature of a narrative review, although a reproducible search strategy was utilized. Several neuromodulation modalities have minimal published evidence available. CONCLUSIONS: The evidence for neuromodulation devices for the treatment of PDN mostly comprises open-label prospective trials or case reports. SCS has the most volume of evidence for efficacy. Studies regarding TENS show mixed results, possibly due to numerous device varieties. PNS and ST may hold promise based on their proposed mechanisms of action, but prospective controlled trials are needed.

Treatment Efficacy and Technical Advantages of Temporary Spinal Nerve Root Stimulation Compared to Traditional Spinal Cord Stimulation for Postherpetic Neuralgia.

BACKGROUND: Postherpetic neuralgia (PHN) is a common complication after herpes zoster infection. While conventional dorsal column temporary spinal cord stimulation (tSCS) has been shown as an effective treatment option for this pain condition, recent data suggests ipsilateral temporary spinal nerve root stimulation (tSNRS) as a safe alternative for treating PHN. However, there is no direct clinical comparison between the newer tSNRS and the traditional tSCS. OBJECTIVES: The current retrospective study aimed to describe the technical factors and the therapeutic efficacy of tSNR for patients with unilateral PHN and to compare these parameters with those treated with tSCS. STUDY DESIGN: Retrospective cohort study. SETTING: Single-center study in a large academic hospital. METHODS: One hundred sixty patients with unilateral PHN who underwent 7-14 days of tSCS (n = 109) or tSNRS (n = 51) treatment were included. Technical factors between the 2 groups, such as procedure time, radiation dosage, number of electrodes used, number of stimulation parameter adjustments, and average cost, were compared. Treatment efficacy, measured by analgesic coverage, pain visual analog scale (VAS), total analgesic agent consumption, Pittsburgh sleep quality index (PSQI), and physical and mental quality of life, were also compared between the 2 groups at baseline, post-procedure, and 3 months after stimulation treatment. RESULTS: Patients who underwent tSNRS reported significant improvement in pain level, sleep quality, and overall quality of life immediately postprocedure and during the follow-up period. This therapeutic effect was comparable to the tSCS group. Moreover, tSNRS achieved this therapeutic effect with a fewer number of implanted electrodes and stimulation adjustments than tSCS. The precision and consistency of the tSNRS technique were associated with a significant overall lower cost, a shorter procedure time, and less intraoperative radiation exposure in the tSNRS group than in those who received tSCS. LIMITATIONS: The current retrospective cohort study was limited by its relatively short follow-up period. Also, the selection of stimulation techniques was not randomized. CONCLUSIONS: While tSNRS provides similar therapeutic efficacy compared to tSCS for patients with unilateral PHN; it offers several technical advantages. These advantages include shorter procedure time, less radiation exposure, fewer implanted electrodes, more effective stimulation, and lower overall cost.

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.

Spinal cord stimulation for treatment of complex regional pain syndrome: a single-centre retrospective case series study.

INTRODUCTION: Complex regional pain syndrome (CRPS) is a debilitating disease with limited available treatment options. Spinal cord stimulation (SCS) is a universal option that promises to improve quality of life by reducing intractable neuropathic pain. The aim of this study was to describe the effectiveness and safety of SCS as a treatment for CRPS patients. CLINICAL RATIONALE FOR THE STUDY: SCS as an invasive method has relatively recently been introduced to CRPS therapy. We hypothesised that by assessing the effectiveness and safety of SCS, we could justify its early use in the treatment of this debilitating condition. MATERIAL AND METHODS: CRPS is a multifactorial and disabling disorder with complex aetiopathogenesis. The primary goals of CRPS treatment include pain relief, functional restoration, and psychological stabilisation. Early intervention is needed to achieve these objectives. In this study, we performed a retrospective evaluation of clinical outcomes in seven patients with severe, intractable CRPS treated by SCS. All patients underwent implantation of a non-rechargeable prime advanced MRI implantable pulse generator (IPG) (Medtronic, Minneapolis, MN, USA) between December 2017 and December 2020 using identical surgical and intraprocedural techniques. RESULTS: From a total of 21 patients treated with SCS over the three years in question, seven (33%) were diagnosed with severe CRPS. The duration of chronic pain ranged between two and 12 years. In six cases (86%), an electrode was implanted in the thoracic segment. Good (partial pain reduction) or very good (complete pain relief) treatment results were observed in five patients (72%). In two cases (28%), two revision surgeries were performed for wound debridement. These hardware-related complications were primarily related to erosions located over implanted IPG's. CONCLUSIONS AND CLINICAL IMPLICATIONS: SCS is the best alternative for patients with CRPS. It should be used immediately after the failure of conservative treatment. Despite the relatively high complication rate in our series, it is the best choice for pain reduction management in this select group of patients.

Dorsal Root Ganglion Stimulation as a Salvage Therapy Following Failed Spinal Cord Stimulation.

INTRODUCTION: Spinal cord stimulation (SCS) can provide long-term pain relief for various chronic pain conditions, but some patients have no relief with trial stimulation or lose efficacy over time. To "salvage" relief in patients who do not respond or have lost efficacy, alternative stimulation paradigms or anatomical targets can be considered. Dorsal root ganglion stimulation (DRG-S) has a different mechanism of action and anatomical target than SCS. OBJECTIVES: We assessed DRG-S salvage therapy outcomes in patients who did not respond to SCS or had lost SCS efficacy. MATERIALS AND METHODS: We retrospectively included consecutive patients from 2016 to 2020 who were salvaged with DRG-S after failed SCS trials (<50% pain reduction) or who had lost efficacy after permanent SCS. We compared numerical rating scale (NRS) pain, Oswestry disability index (ODI), health-related quality of life (EuroQol five-dimensions five-level), and oral morphine equivalent (OME) opioid requirements before DRG-S salvage and at patients' last follow-up. RESULTS: A total of 60 patients who had failed SCS were salvaged with DRG-S. The mean age was 56 ± 12 years, and the most common diagnoses were complex regional pain syndrome (n = 24) and failed back surgery syndrome (n = 24). The most common failed modalities included tonic (n = 32), Burst (n = 18), and high-frequency (n = 10) SCS. The median follow-up duration of salvage DRG-S was 34 months. With DRG-S, NRS decreased (8.7 ± 1.2 to 3.8 ± 2.1), and OME declined (median 23 mg to median 15 mg), whereas EuroQol 5D scores increased (0.40 ± 0.15 to 0.71 ± 0.15), and ODI improved (64 ± 14% to 31 ± 18%) (all p < 0.05). CONCLUSIONS: DRG-S can be used in patients with chronic pain who have previously failed to receive persistent benefit from SCS.

Characterization of interlimb interaction via transcutaneous spinal stimulation of cervical and lumbar spinal enlargements.

The use of transcutaneous electrical spinal stimulation (TSS) to modulate sensorimotor networks after neurological insult has garnered much attention from both researchers and clinicians in recent years. Although many different stimulation paradigms have been reported, the interlimb effects of these neuromodulation techniques have been little studied. The effects of multisite TSS on interlimb sensorimotor function are of particular interest in the context of neurorehabilitation, as these networks have been shown to be important for functional recovery after neurological insult. The present study utilized a condition-test paradigm to investigate the effects of interenlargement TSS on spinal motor excitability in both cervical and lumbosacral motor pools. Additionally, comparison was made between the conditioning effects of lumbosacral and cervical TSS and peripheral stimulation of the fibular nerve and ulnar nerve, respectively. In 16/16 supine, relaxed participants, facilitation of spinally evoked motor responses (sEMRs) in arm muscles was seen in response to lumbosacral TSS or fibular nerve stimulation, whereas facilitation of sEMRs in leg muscles was seen in response to cervical TSS or ulnar nerve stimulation. The decreased latency between TSS- and peripheral nerve-evoked conditioning implicates interlimb networks in the observed facilitation of motor output. The results demonstrate the ability of multisite TSS to engage interlimb networks, resulting in the bidirectional influence of cervical and lumbosacral motor output. The engagement of interlimb networks via TSS of the cervical and lumbosacral enlargements represents a feasible method for engaging spinal sensorimotor networks in clinical populations with compromised motor function.NEW & NOTEWORTHY Bidirectional interlimb modulation of spinal motor excitability can be evoked by transcutaneous spinal stimulation over the cervical and lumbosacral enlargements. Multisite transcutaneous spinal stimulation engages spinal sensorimotor networks thought to be important in the recovery of function after spinal cord injury.

Understanding the role of patient preference in the treatment algorithm for chronic low back pain: results from a survey-based study.

Aims: Interventional pain treatments range from injections to established radiofrequency ablation techniques and finally neuromodulation. In addition to safety, efficacy and cost dominance, patient preference for type of treatment is important. Methods: Chronic pain patients (n = 129) completed a preference scale to determine which interventional pain management procedures they would prefer from among radiofrequency ablation, temporary (60-day) peripheral nerve stimulation (PNS), conventional PNS and spinal cord stimulation/dorsal root ganglion stimulation. A second survey (n = 347) specific to assessing the preference for radiofrequency ablation or temporary PNS treatment was completed by patients with low back pain. Results: On the basis of mean rank, temporary PNS percutaneously implanted for up to 60 days was the most preferred treatment compared with the other options presented (p = 0.002). Conclusions: Patient preference should be unbiased and considered as an independent variable for physician discussion in treatment options and future research.

Patient preference is an important variable for physicians to consider when discussing treatment options for low back pain. A consumer survey study was completed discussing patient preference among various invasive treatments for low back pain. When given scenarios discussing risks and benefits of each procedure (temporary peripheral nerve stimulation for 60 days, heat ablation of small back nerves and permanently implanted back pain devices) temporary peripheral nerve stimulation was considered the preferred option.

Transcutaneous Spinal Neuromodulation Reorganizes Neural Networks in Patients with Cerebral Palsy.

Spinal neuromodulation and activity-based rehabilitation triggers neural network reorganization and enhances sensory-motor performances involving the lower limbs, the trunk, and the upper limbs. This study reports the acute effects of Transcutaneous Electrical Spinal Cord Neuromodulation (SCONE™, SpineX Inc.) on 12 individuals (ages 2 to 50) diagnosed with cerebral palsy (CP) with Gross Motor Function Classification Scale (GMFCS) levels ranging from I to V. Acute spinal neuromodulation improved the postural and locomotor abilities in 11 out of the 12 patients including the ability to generate bilateral weight bearing stepping in a 2-year-old (GMFCS level IV) who was unable to step. In addition, we observed independent head-control and weight bearing standing with stimulation in a 10-year-old and a 4-year old (GMFCS level V) who were unable to hold their head up or stand without support in the absence of stimulation. All patients significantly improved in coordination of flexor and extensor motor pools and inter and intralimb joint angles while stepping on a treadmill. While it is assumed that the etiologies of the disruptive functions of CP are associated with an injury to the supraspinal networks, these data are consistent with the hypothesis that spinal neuromodulation and functionally focused activity-based therapies can form a functionally improved chronic state of reorganization of the spinal-supraspinal connectivity. We further suggest that the level of reorganization of spinal-supraspinal connectivity with neuromodulation contributed to improved locomotion by improving the coordination patterns of flexor and extensor muscles by modulating the amplitude and firing patterns of EMG burst during stepping.

Neuromodulation for chronic pain.

Neuromodulation is an expanding area of pain medicine that incorporates an array of non-invasive, minimally invasive, and surgical electrical therapies. In this Series paper, we focus on spinal cord stimulation (SCS) therapies discussed within the framework of other invasive, minimally invasive, and non-invasive neuromodulation therapies. These therapies include deep brain and motor cortex stimulation, peripheral nerve stimulation, and the non-invasive treatments of repetitive transcranial magnetic stimulation, transcranial direct current stimulation, and transcutaneous electrical nerve stimulation. SCS methods with electrical variables that differ from traditional SCS have been approved. Although methods devoid of paraesthesias (eg, high frequency) should theoretically allow for placebo-controlled trials, few have been done. There is low-to-moderate quality evidence that SCS is superior to reoperation or conventional medical management for failed back surgery syndrome, and conflicting evidence as to the superiority of traditional SCS over sham stimulation or between different SCS modalities. Peripheral nerve stimulation technologies have also undergone rapid development and become less invasive, including many that are placed percutaneously. There is low-to-moderate quality evidence that peripheral nerve stimulation is effective for neuropathic pain in an extremity, low quality evidence that it is effective for back pain with or without leg pain, and conflicting evidence that it can prevent migraines. In the USA and many areas in Europe, deep brain and motor cortex stimulation are not approved for chronic pain, but are used off-label for refractory cases. Overall, there is mixed evidence supporting brain stimulation, with most sham-controlled trials yielding negative findings. Regarding non-invasive modalities, there is moderate quality evidence that repetitive transcranial magnetic stimulation does not provide meaningful benefit for chronic pain in general, but conflicting evidence regarding pain relief for neuropathic pain and headaches. For transcranial direct current stimulation, there is low-quality evidence supporting its benefit for chronic pain, but conflicting evidence regarding a small treatment effect for neuropathic pain and headaches. For transcutaneous electrical nerve stimulation, there is low-quality evidence that it is superior to sham or no treatment for neuropathic pain, but conflicting evidence for non-neuropathic pain. Future research should focus on better evaluating the short-term and long-term effectiveness of all neuromodulation modalities and whether they decrease health-care use, and on refining selection criteria and treatment variables.

Neuromodulation for Medically Refractory Neuropathic Pain: Spinal Cord Stimulation, Deep Brain Stimulation, Motor Cortex Stimulation, and Posterior Insula Stimulation.

BACKGROUND: The treatment of neuropathic pain (NP) continues to be controversial as well as an economic health issue and a challenge to health care. Neurosurgery can offer different methods of neuromodulation that may improve patients' condition, including deep brain stimulation (DBS), motor cortex stimulation (MCS), spinal cord stimulation (SCS), and posterior insula stimulation (PIS). There is no consensus of opinion as to the final effects of these procedures, which stimulation parameters to select, the correct timing, or how to select the patients who will best benefit from these procedures. OBJECTIVE: To review the evidence available regarding these 4 procedures and the management of NP. METHODS: We conducted a PubMed, Embase, and Cochrane Library database search from 1990 to 2020. The strategy of the search concentrated on the following keywords: "neuropathic pain," "chronic pain," "deep brain stimulation," "motor cortex stimulation," "spinal cord stimulation," "insula stimulation," and "neuromodulation." Studies that provided data regarding the immediate and long-term effectiveness of the procedure, anatomic stimulation target, percentage of pain control, and cause of the NP were included. RESULTS: The most frequent causes of NP were phantom limb pain and central poststroke pain in the MCS group; central poststroke pain, phantom limb pain, and spinal cord injury (SCI) in the DBS group; and complex regional pain syndrome and failed back surgery syndrome in the SCS group. Pain improvement varied between 35% and 80% in the MCS group and 50% and 60% in the DBS group. In the SCS group, successful rates varied between 38% and 89%. CONCLUSIONS: This systematic review highlights the literature supporting SCS, DBS, MCS, and PIS methods for the treatment of NP. We found consistent evidence supporting MCS, DBS, and SCS as possible treatments for NP; however, we were not able to define which procedure should be indicated for each cause. Furthermore, we did not find enough evidence to justify the routine use of PIS. We conclude that unanswered points need to be discussed in this controversial field and emphasize that new research must be developed to treat patients with NP, to improve their quality of life.