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Background: Spinal cord stimulation (SCS) is a highly effective therapy for treating and management of refractory chronic pain. However, complex nature of pain and infrequent in-clinic visits, determining subject’s long-term response to the therapy remains difficult. Frequent measurement of pain in this population can help with early diagnosis, disease progression monitoring, and evaluating long-term therapeutic efficacy. This paper compares the utilization of the common subjective patient-reported outcomes with objective measures captured through a wearable device for predicting the response to SCS therapy. Method: Data is from the ongoing international prospective post-market REALITY clinical study, which collects long-term patient-reported outcomes from 557 subjects and the sub-study designed for collecting additional wearables data on a subset of participants for up to six months after SCS implantation. We first implemented a combination of dimensionality reduction algorithms and correlation analyses to explore the mathematical relationships between objective wearable data and subjective patient-reported outcomes. We then developed machine learning models to predict SCS therapy outcome based on the subject’s response to NRS or PGIC. Results: Principal component analysis results showed that psychological aspects of pain were closely associated with heart rate variability, while movement-related measures were closely associated with patient-reported outcomes related to physical function and social role participation. Our machine learning models using objective wearable data predicted both PGIC and NRS outcomes with high accuracy in the absence of subjective data. The prediction accuracy was higher for PGIC compared with the NRS using subjective-only measures primarily driven by the patient satisfaction feature. Similarly, the PGIC questions, reflects an overall change since the study onset and could be a better predictor of long-term therapy outcome. Conclusions: The significance of this study is to introduce a novel use of wearable data collected from a subset of patients to capture multi-dimensional aspects of pain and compare the prediction power with the subjective data from a larger data set. The discovery of pain digital biomarkers could result in a better understanding of the patient’s response to therapy and their general well-being.

Spinal Cord Stimulation (SCS) is a well-established therapy for treating chronic pain. However, treatment response to SCS therapy may vary among people with chronic pain due to diverse pain perspectives amongst them. While, currently, chronic pain is evaluated by clinically validated patient reported outcomes (PROs) measures completed during a clinical assessment, monitoring improvement of the participant’s progress over time and comparison of PROs across participants remains subjective and challenging. Thus, objective measures to quantify pain are invaluable. This study aims to assess the feasibility of using digital biomarkers collected from wearables during SCS treatment to predict pain and PRO outcomes. Twenty participants with chronic pain were recruited and implanted with SCS. During the six months of the study, activity and physiological metrics were collected and data from 15 participants was used to develop a machine learning pipeline to objectively predict pain and PRO measures. We were able to reach the accuracy of 0.832 ± 0.012 in pain intensity prediction. The feature importance analysis showed that digital biomarker from the smart watch such as heart rate, heart rate variability, step count, and stand time can contribute to modeling different aspects of pain. The results of the study suggest that wearable biomarkers can be used to predict therapy outcomes in people with chronic pain and bring us another step closer towards objective evaluation of chronic pain.

Sacroiliac joint disease is a prominent diagnosis across the world. A novel fixation technique employing a posterior approach, single point, bone allograft transfixation has proven to be helpful anecdotally. The purpose of this is study is to investigate prospectively the safety and efficacy of this approach.A multicenter, prospective, single arm study was performed after patient identification and treatment with the novel posterior fusion, single-point transfixation system and followed for 24 months. Target enrollment is 100 patients. Interim results on the first 69 consecutive patients at 6 months is presented. Primary endpoint at 6-month analysis was Pain Intensity reduction by visual analogue scale and functional improvement by Oswestry Disability Index. Adverse events were assessed for safety analysis.In total, 69 patients were identified for this analysis. At 6 months, a mean improvement of 34.9 was identified by a reduction in VAS and functional improvement was demonstrated by a mean reduction in ODI of 17.7. There were three adverse events, all unrelated to the device.The posterior single point transfixation is safe and efficacious for the treatment of sacroiliac joint dysfunction with statistical improvements in pain and function.

Background Nutcracker syndrome is a rare disorder caused by compression of the left renal vein, usually between the aorta and the superior mesenteric artery. It typically presents with left-sided abdominal pain and hematuria. Left renal vein transposition is the most commonly employed surgical technique to alleviate the compression. Case presentation A 22-year-old Caucasian man with a known diagnosis of nutcracker syndrome had undergone left renal vein transposition 1 year before presentation without any subsequent pain relief. In addition, his surgery was complicated by massive blood loss and a 1-week-long stay in an intensive care unit (ICU); as such, he was not amenable to further surgical intervention or stenting to treat his underlying pathology. His symptoms included constant sharp left-sided flank, perineal, and testicular pain. A series of ganglion impar blocks were performed every 3–4 months over the course of 5 years with substantial pain relief achieved. Conclusions Our case report highlights a treatment option that has not yet been described for patients with pain secondary to nutcracker syndrome refractory to surgical intervention.

INTRODUCTION: The Neuromodulation Appropriateness Consensus Committee (NACC) is dedicated to improving the safety and efficacy of neuromodulation and thus improving the lives of patients undergoing neuromodulation therapies. With continued innovations in neuromodulation comes the need for evolving reviews of best practices. Dorsal root ganglion (DRG) stimulation has significantly improved the treatment of complex regional pain syndrome (CRPS), among other conditions. Through funding and organizational leadership by the International Neuromodulation Society (INS), the NACC reconvened to develop the best practices consensus document for the selection, implantation and use of DRG stimulation for the treatment of chronic pain syndromes. METHODS: The NACC performed a comprehensive literature search of articles about DRG published from 1995 through June, 2017. A total of 2538 article abstracts were then reviewed, and selected articles graded for strength of evidence based on scoring criteria established by the US Preventive Services Task Force. Graded evidence was considered along with clinical experience to create the best practices consensus and recommendations. RESULTS: The NACC achieved consensus based on peer-reviewed literature and experience to create consensus points to improve patient selection, guide surgical methods, improve post-operative care, and make recommendations for management of patients treated with DRG stimulation. CONCLUSION: The NACC recommendations are intended to improve patient care in the use of this evolving therapy for chronic pain. Clinicians who choose to follow these recommendations may improve outcomes.

Introduction Intractable complex regional pain syndrome (CRPS)-related chronic foot pain, is a common therapeutic challenge for interventional pain management physicians and patients alike. Dorsal root ganglia (DRG) stimulation is a very target specific dorsal column stimulation technique with very promising clinical outcomes. Patients with CRPS foot pain and previous back surgery can benefit from DRG stimulation but also run a significant risk of epidural trauma from the DRG sheath advancement. Most sensory innervation to the foot is from L5 and S1 dermatomes. Although there is dual modulation from L5 and S1 DRG, significant "cross talk" exists between these structures such that a DRG lead solely at S1 could provide pain relief for the entire foot. In this case series, we examined the outcomes obtained from placement of solely S1 DRG stimulating electrodes in patients with CRPS-related chronic foot pain, and examine whether this may provide a reduced risk of dural injury. Furthermore, we describe the technical aspects of a S1 DRG placement and discuss relevant anatomical issues pertaining to this approach. Materials and methods Five patients (four female, one male) with chronic foot pain participated. The oldest was 71 and the youngest 49. Three patients were diagnosed with foot CRPS-1, and two patients with foot CRPS-2. All patients had back surgery in the past and all underwent a trial and subsequent S1 DRG implantation. The patients were evaluated with a numeric rating score (NRS) for pain and function before the procedure and one, two, three, and six months after the procedure. The first patient underwent an L5 and S1 trial and developed CSF leak and postdural puncture headache. Two months later, the patient was re-trialed and implanted with a single S1 electrode. The other four patients were trialed and implanted with single S1 DRG electrodes. Results All five patients had severe pain (8-10 NRS) and significant loss of function and quality of life (2-4 NRS) before the procedure. All five patients had excellent (0-3 NRS) pain relief and functional restoration (8-10 NRS) with a single S1 electrode trial, and all five proceeded with permanent implantation. The pain relief from the S1 DRG stimulation extended to the entire foot without any sparing. All patients were able to discontinue or significantly reduce their oral pain medications. The one-, two-, three-, and six-month follow-up showed preservation of therapeutic efficacy. Conclusions A single S1 DRG electrode placement in patients diagnosed with CRPS of the foot and who had previous back surgery is therapeutically effective and can minimize the risk of dural trauma and CSF leak.

Introduction Spinal cord stimulation (SCS) devices are cost effective and improve function as well as quality of life. Despite the demonstrated benefits of SCS, some patients have the device explanted. We are interested in exploring the patient characteristics of those explanted. Methods This is a retrospective chart review of neurostimulation patients who underwent explantation at 18 centers across the United States within the previous five years. Results Data from 352 patients were collected and compiled. Failed Back Surgery syndrome was the most common diagnosis (38.9%; n = 136/350) and over half of the patients reported numerical rating scale (NRS) scores ≥8 prior to implant (64.3%; n = 207/322). All patients reported changes in NRS scores across time, with an initial decrease after implant followed by a pre-explant increase (F (2, 961) = 121.7, p

Objectives The objective of this study was to present results from a multicenter registry designed to obtain longitudinal clinical outcome data for patients implanted with a neuromodulation system for the management of chronic pain of the trunk and/or limbs. Materials and Methods Interim data from 579 patients across 40 study sites were analyzed from a prospective, observational, noninterventional registry. Institutional review board approval was obtained prior to enrollment. The following were recorded at baseline and at 3, 6, and 12 months postimplant: patient-reported pain relief, categorical ratings of pain relief, Pain Disability Index (PDI) scores, quality of life, medication usage, and patient satisfaction. Pain relief among (tobacco) smokers was also assessed. Descriptive statistics were compiled for all patient outcome measurements, and data are reported as mean (±standard deviation). All statistical analysis was conducted using one-sided t-tests with a significance level of α = 0.05. Device-related adverse events were captured and are reported. Results Patient-reported pain relief was 58.0% (±26.2%) at 3 months, 58.1% (±28.7%) at 6 months, and 57.0% (±29.4%) at 12 months. Mean PDI scores were reduced from 47.7 points at baseline to 33.3, 32.4, and 31.9 points, respectively (p ≤ 0.001). The majority of patients categorized their pain relief as “excellent” or “good” and reported their overall quality of life as “greatly improved” or “improved” at all time points. In addition, greater than 79% of patients were “satisfied” or “very satisfied” with the therapy at all time points assessed, and 47.1% of patients “stopped” or “decreased” use of narcotics/opioids. Pain relief was significantly attenuated by smoking (p = 0.042). The most common adverse event was persistent pain and/or numbness at implantable pulse generator/lead site, which accounted for 18.6% of all events in 3.2% of all patients. Conclusions These results provide evidence to further support the safety, efficacy, and sustainability of neuromodulation in clinical practice.

Objective: Epidural steroid injections (ESI) are used extensively to treat radicular back pain. This study is designed to evaluate the types and dosages of steroids commonly used and understand prescribing habits of the Texas Pain Society pain management physicians. Method: From April to May 2014, we sent all 270 Texas Pain Society members a questionnaire to complete online. We collected 45 responses. Result: Type of steroid commonly used in injectate: Eighteen (41.9%) phy-sicians reported using methylprednisolone most. Fifteen (34.9%) physicians use triamcinolone, 9 (20.9%) physicians use dexamethasone, 1 (2.3%) uses betamethasone, and 2 skipped this question. Important factors influencing the type of steroid use in injectate: Half of the physicians reported that the location of the ESI was most important (19 responses, 48.7%). Ten (25.6%) reported that the approach of the ESI was most important. Another ten (25.6%) agreed that the potency of the steroid was most important. Dosage of steroid used in injectate: About half of the physicians use a fixed dose of steroid (22, 51.2%) while 21 (48.8%) use a variable dose of steroid. Of those who use a fixed dose of steroid, many use methylprednisolone 80 mg (9, 39.1%). Of those who use a variable dosage of steroid, the most important factor in their determination of the dosage is the patient’s comorbidities (20 responses, 58.8%). The use of depo-steroid in injectate: Thirty-two out of 43 (74.4%) use depo-steroid while 11 out of 43 (25.6%) wouldn’t use depo-steroid. Of those who use depo-steroid, the duration and availability in the epidural space is the most common reason for its use (23, 76.7%). Conclusion: By using a simple questionnaire detailing what types and dosages of steroids are used, compiling a list of best practices can help Texas Pain Society physicians tremendously in the treatment of radicular back pain.

Occipital nerve stimulation (ONS) is a peripheral nerve stimulation (PNS) technique that has been used with success in the management of intractable chronic daily headaches (CDHs) and occipital neuralgia (ON). The technique involves the placement of a stimulating surgical or percutaneous electrode over the occipital nerves within the subcutaneous tissues at the skull base. Until recently, procedures involving the occipital nerves were based on identifying bony or arterial landmarks with direct palpation or fluoroscopy. Although universally accepted as an imaging technique, fluoroscopy does not provide real-time imaging of the occipital nerves or vessels. Furthermore, therapeutic efficacy of ONS is directly related to the ability of the stimulating electrode to produce peripheral nerve dermatomal paresthesia, emphasizing the need for precision placement. A total of six patients, diagnosed with refractory CDH and ON, after failing extensive medical management, were diagnosed as potential candidates for ONS. Subsequently, all underwent successful percutaneous trials of bilateral octopolar (Advanced Neuromodulation Systems, Plano, TX, USA) ONS under ultrasound guidance, followed by permanent surgical implantation. In this case series, ultrasound provided accurate, real-time placement of introducer needles and stimulating electrodes by allowing visualization of tissue planes (epidermis, dermis, subcutaneous fat, and trapezious muscle), as well as vessels and nervous structures. Ultrasound imaging has been used increasingly for peripheral nerve blockade in surgical anesthesia and in chronic pain management as it allows real-time localization of both nervous and vascular structures (color flow Doppler) and, thus, a method for increasing blockade precision and safety. As an adjunct to ONS, the position of the introducer needles and electrodes can be visualized in relation to the occipital nerves and vasculature. This reproducible positioning allows accurate depth of placement (assuring production of the prerequisite PNS dermatomal paresthesia required for ONS efficacy) and limits the risk of injury to the occipital artery or nerve(s). In this case series, ultrasonography provided real-time, safe, and reliable placement of ONS electrodes. It also allowed identification of nervous and vascular structures unable to be seen with fluoroscopy, The portable nature of modern ultrasound machines, together with an ever improving pixelation of the Doppler color flow images/real-time measurements, and a lack of radiation exposure make this technology an attractive emerging modality in the field of Neuromodulation.

Objective This longitudinal, clinical outcome study was a multicenter, prospective, observational, registry with a 24-month assessment of patients implanted with spinal cord stimulation (SCS) systems for the management of chronic pain of the trunk and/or limbs. Methods On informed consent and institutional review board approval, 614 patients from 39 sites were enrolled within 30 days following permanent SCS system implantation. Medication usage, patient-reported pain relief (PRP), categorical ratings of pain relief, pain disability index scores (PDI), quality of life (QoL), and patient satisfaction were assessed at enrollment, 3-, 6-, 12-, 18-, and 24-month postimplant. Device-related adverse events (AEs) were recorded and reported. Results Across all visits, statistically significant improvements were reported on all outcome measures. Mean PRP was 58.5% (± 26.4) at 3 months, 56.8% (± 29.2) at 6 months, 57.7% (± 28.9) at 12 months, 55.6% (± 29.8) at 18 months, and 56.3% (± 30.3) at 24 months. More than 65% of patients at any visit reported a PRP ≥ 50%. Mean PDI scores reduced from 46.9 points at baseline to 32.7, 31.8, 31.5, 32.1, 32.1 points at 3, 6, 12, 18, and 24 months (p ≤ 0.0001), respectively. Greater than 76% of patients at any visit were satisfied with their therapy. The majority of patients categorized pain relief as excellent or good on a 5-item scale and reported overall QoL as greatly improved or improved on a 5-item scale. An average of 88% of patients stopped, decreased, or did not change dose of narcotics/opioids. The most common AE was diminished or loss of pain relief in 11.4% of enrolled patients. Conclusions Most patients experienced substantial pain relief and a significant improvement in all outcome measures. These results further support the safety, efficacy, and sustainability of SCS in clinical practice.

Objective: To show the value of computed tomography (CT) in selectively blocking the pudendal nerve in patients with long-term anogenital pain of uncertain etiology. We report a technique to selectively block the pudendal nerve using CT guidance in 2 patients with long-term anogenital pain. Case Report: In 1 patient, a competitive cyclist, the diagnosis of pudendal neuralgia was substantiated by blocking the nerve under CT. The procedure relieved the pain for approximately 24 hours. In the other patient, pudendal nerve block produced perineal analgesia but no pain relief. Superior hypogastric plexus block relieved the pain significantly for about 4 weeks on 2 separate occasions, suggesting sympathetically maintained pain. Conclusion: The use of CT to guide the procedure allowed precision in performing the procedure and in making a differential diagnosis. Reg Anesth Pain Med 2000;25:420-423.

Objectives: Charcot-Marie-Tooth (CMT) disease is one of the most common hereditary neuropathies affecting one in 2500 people in the United States. CMT disease is associated with moderate to severe chronic extremity pain. We present the case of a young man with chronic intractable lower extremity pain associated with CMT disease treated with spinal cord stimulation (SCS). Materials and Methods: This was an Institutional Review Board-approved case study involving a 37-year-old man diagnosed with CMT disease with pain of more than 20 years. He was implanted with an SCS device and patient pain and quality of life was assessed one and six months later using the SF-McGill Pain Questionnaire, Visual Analog Scale, Oswestry Disability Questionnaire, Pain Disability Index, and SF-36. Baseline measures were obtained retrospectively. Qualitative data were collected from the medical record. Results: SCS was effective in decreasing pain, improving quality of life and reducing medication consumption at both one and six months post-implant. In addition, the patient was satisfied with SCS treatment. Conclusion: SCS produced favorable results in a patient with CMT and should be considered a treatment option for pain resulting from this condition.

The sacroiliac joint as a source of chronic pain has been a subject of debate for a long period of time. This controversy stems from the inherent anatomic location of the sacroiliac joint. Adjacent spinal structures may cause pain to be referred to the sacroiliac joint, thus making a precise diagnosis difficult. The most reliable method to establish the diagnosis of sacroiliac arthralgia is fluoroscopic-guided intra-articular injection of a local anesthetic preceded by a sacroiliac arthrogram. Although there are many therapeutic options for sacroiliac joint syndrome, the ideal treatment has not yet been discovered. There is evidence that intra-articular viscosupplementation of the sacroiliac joint with hylan can consistently and reliably induce a prolonged analgesic response in sacroiliac joint syndrome. Viscosupplementation restores joint homeostasis, allows increased joint motion, and induces analgesia. Hylan is highly viscoelastic hyaluronan (hyaluronic acid), and is capable of increasing the viscoelastic properties of synovial fluid.

Introduction Occipital peripheral nerve stimulation is an interventional pain management therapy that provides beneficial results in the treatment of refractory chronic occipital neuralgia. Herein we present a first-of-its-kind case study of a patient with neurofibromatosis type 1 and bilateral occipital neuralgia treated with occipital peripheral nerve stimulation. Case presentation A 42-year-old Caucasian woman presented with bilateral occipital neuralgia refractory to various conventional treatments, and she was referred for possible treatment with occipital peripheral nerve stimulation. She was found to be a suitable candidate for the procedure, and she underwent implantation of two octapolar stimulating leads and a rechargeable, programmable, implantable generator. The intensity, severity, and frequency of her symptoms resolved by more than 80%, but an infection developed at the implantation site two months after the procedure that required explantation and reimplantation of new stimulating leads three months later. To date she continues to experience symptom resolution of more than 60%. Conclusion These results demonstrate the significance of peripheral nerve stimulation in the management of refractory occipital neuralgias in patients with neurofibromatosis type 1 and the possible role of neurofibromata in the development of occipital neuralgia in these patients.