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

INTRODUCTION: The use of spinal cord stimulation (SCS) therapy to treat chronic pain continues to rise. Optimal patient selection remains one of the most important factors for SCS success. However, despite increased utilization and the existence of general indications, predicting which patients will benefit from neuromodulation remains one of the main challenges for this therapy. Therefore, this study aims to identify the variables that may correlate with nonresponders to high-frequency (10 kHz) SCS to distinguish the subset of patients less likely to benefit from this intervention. MATERIALS AND METHODS: This was a retrospective single-center observational study of patients who underwent 10 kHz SCS implant. Patients were divided into nonresponders and responders groups. Demographic data and clinical outcomes were collected at baseline and statistical analysis was performed for all continuous and categorical variables between the two groups to calculate statistically significant differences. RESULTS: The study population comprised of 237 patients, of which 67.51% were responders and 32.49% were nonresponders. There was a statistically significant difference of high levels of kinesiophobia, high self-perceived disability, greater pain intensity, and clinically relevant pain catastrophizing at baseline in the nonresponders compared to the responders. A few variables deemed potentially relevant, such as age, gender, history of spinal surgery, diabetes, alcohol use, tobacco use, psychiatric illness, and opioid utilization at baseline were not statistically significant. CONCLUSION: Our study is the first in the neuromodulation literature to raise awareness to the association of high levels of kinesiophobia preoperatively in nonresponders to 10 kHz SCS therapy. We also found statistically significant differences with greater pain intensity, higher self-perceived disability, and clinically relevant pain catastrophizing at baseline in the nonresponders relative to responders. It may be appropriate to screen for these factors preoperatively to identify patients who are less likely to respond to SCS. If these modifiable risk factors are present, it might be prudent to consider a pre-rehabilitation program with pain neuroscience education to address these factors prior to SCS therapy, to enhance successful outcomes in neuromodulation.

A Prospective, Randomized Single-Blind Crossover Study Comparing High-Frequency 10,000 Hz and Burst Spinal Cord Stimulation.

OBJECTIVES: Although both high-frequency and burst spinal cord stimulation (SCS) have shown improved efficacy and patient satisfaction compared with conventional tonic stimulation, there are limited data directly comparing the two. This study aimed to compare both high-frequency 10,000 Hz and burst SCS in the same patients in terms of pain relief and satisfaction in those with axial back pain with or without leg pain. MATERIALS AND METHODS: This prospective, single-blind, randomized controlled trial was conducted at an outpatient pain clinic within an academic medical center. Participants were randomly allocated to one of two groups in which they trialed either burst or high-frequency 10,000 Hz SCS over five days, followed by a 24- to 48-hour washout period with no stimulation, and the alternative therapy over the remaining four days. Visual analog scale (VAS) scores were collected immediately before and after both therapy trials. Secondary end points included percentage change in VAS score and patient preference. RESULTS: Of 25 participants, those receiving burst followed by high-frequency SCS (n = 11) had a mean VAS difference of 4.73 after the first trial period and 2.86 after the second. Of those receiving high-frequency followed by burst SCS (n = 14), mean VAS difference after the first trial period was 4.00 and 1.93 after the second trial period. Four participants were withdrawn owing to lead migration. Both therapies showed statistically significant differences in pre- minus post-VAS scores and percent relief. There were no significant differences in carryover or treatment effects between the two groups. There was a statistically significant association between trial sequence and stimulator type implanted because the first stimulator trialed was more likely to be chosen. CONCLUSIONS: There were no observed differences in VAS pain score decrease when comparing burst and high-frequency 10,000 Hz SCS programming therapies. Patient preference followed an order effect, favoring the first programming therapy in the trial sequence.

Healthcare Utilization (HCU) Reduction with High-Frequency (10 kHz) Spinal Cord Stimulation (SCS) Therapy.

Spinal cord stimulation (SCS) is a well-established treatment for patients with chronic pain. With increasing healthcare costs, it is important to determine the benefits of SCS in healthcare utilization (HCU). This retrospective, single-center observational study involved 160 subjects who underwent implantation of a high-frequency (10 kHz) SCS device. We focused on assessing trends in HCU by measuring opioid consumption in morphine milligram equivalents (MME), as well as monitoring emergency department (ED) and office visits for interventional pain procedures during the 12-month period preceding and following the SCS implant. Our results revealed a statistically significant reduction in HCU in all domains assessed. The mean MME was 51.05 and 26.52 pre- and post-implant, respectively. There was a 24.53 MME overall decrease and a mean of 78.2% statistically significant dose reduction (p < 0.0001). Of these, 91.5% reached a minimally clinically important difference (MCID) in opioid reduction. Similarly, we found a statistically significant (p < 0.01) decrease in ED visits, with a mean of 0.12 pre- and 0.03 post-implant, and a decrease in office visits for interventional pain procedures from a 1.39 pre- to 0.28 post-10 kHz SCS implant, representing a 1.11 statistically significant (p < 0.0001) mean reduction. Our study reports the largest cohort of real-world data published to date analyzing HCU trends with 10 kHz SCS for multiple pain etiologies. Furthermore, this is the first and only study evaluating HCU trends with 10 kHz SCS by assessing opioid use, ED visits, and outpatient visits for interventional pain procedures collectively. Preceding studies have individually investigated these outcomes, consistently yielding positive results comparable to our findings.

The American Society of Pain and Neuroscience (ASPN) Guidelines for Radiofrequency Ablative Procedures in Patients with Implanted Devices.

Radiofrequency ablation (RFA) is a treatment modality used in interventional pain management to treat several conditions including chronic neck or back pain, sacroiliac joint pain, major joint pain, and pain from sites that can be isolated to a sensory nerve amenable to RFA. The goals of such procedures are to reduce pain, improve function, delay need for surgical intervention, and reduce pain medication consumption. As applications for RFA expand through novel techniques and nerve targets, there is concern with how RFA may impact patients with implanted medical devices. Specifically, the electrical currents used in RFA produce electromagnetic interference, which can result in unintentional energy transfer to implanted devices. This may also interfere with device function or cause damage to the device itself. As the number of patients with implanted devices increases, it is imperative to establish guidelines for the management of implanted devices during RFA procedures. This review aims to establish guidelines to assist physicians in the preoperative, intraoperative, and postoperative management of implanted devices in patients undergoing procedures using radiofrequency energy. Here, we provide physicians with background knowledge and a summary of current evidence to allow safe utilization of RFA treatment in patients with implanted devices such as cardiac implantable electronic devices, spinal cord stimulators, intrathecal pumps, and deep brain stimulators. While these guidelines are intended to be comprehensive, each patient should be assessed on an individual basis to optimize outcomes.

Overview of HF10 spinal cord stimulation for the treatment of chronic pain and an introduction to the Senza Omnia™ system.

Chronic intractable pain affects a significant percentage of the worldwide population, and it is one of the most disabling and expensive health conditions across the globe. Spinal cord stimulation (SCS) has been used to treat chronic pain for a number of years, but high-frequency SCS was not the US FDA approved until 2015. In this review, we describe the history and development of high-frequency SCS and discuss the benefits of the Omnia™ implantable pulse generator. We also provide a thorough literature review of the published work, highlighting the efficacy and safety profiles of high-frequency SCS for the treatment of multiple chronic pain conditions. Lastly, we offer our outlook on future developments with the Omnia SCS system.

Spinal Radiofrequency Ablation Combined with Cement Augmentation for Painful Spinal Vertebral Metastasis: A Single-Center Prospective Study.

BACKGROUND: The spine is the most common site of skeletal metastatic disease. Vertebral body metastases (VBM) can cause crippling pain, fractures, and spinal cord compression. Radiofrequency ablation (RFA) is a minimally invasive technique that has proven to be a safe method of targeted tissue destruction. Studies have shown that RFA combined with cement vertebral augmentation is safe and effective and has been associated with significant improvements in pain and quality of life. OBJECTIVES: The purpose of this study was continued evaluation of the safety and efficacy of this technique. STUDY DESIGN: Prospective cohort. SETTING: A single academic medical center. METHODS: Patients undergoing RFA with cement vertebral augmentation for a painful thoracic or lumbar VBM were eligible for inclusion. Additional inclusion criteria included pain concordant with a metastatic lesion on cross-sectional imaging, aged 18 years or older, and considered candidates for spinal tumor ablation by the operating physician. Patients with vertebral metastatic disease in the cervical spine or patients with spinal cord compression from posterior tumor extension were excluded. Ablation within each VBM was performed using a bipolar radiofrequency probe with an extensible electrode and available articulation, permitting vertebral body navigation percutaneously. Patients were evaluated at baseline, 3 days, one week, one month, and 3 months using the Numeric Rating Scale (NRS-11) and Functional Assessment of Cancer Therapy-General 7 (FACT-G7) to assess pain and quality-of-life, respectively. A one-sample t test was performed, and 95% confidence intervals were calculated to assess changes in average NRS-11 and FACT-G7 scores. RESULTS: A total of 30 patients met inclusion criteria and underwent RFA of one or more VBM. Patients with 13 different primary cancers types underwent treatment. Patients received RFA to either one (n = 26; 87%) or 2 vertebral body levels (n = 4; 13%). Of the 34 levels, 13 were thoracic vertebra (38%) and 21 were lumbar vertebra (62%). Average NRS-11 scores decreased from a baseline of 5.77 to 4.65 (3 days; P = 0.16), 3.33 (one week; P < 0.01), 2.64 (one month; P < 0.01), and 2.61 (3 months; P < 0.01). FACT-G7 increased from a baseline average of 13.0 to 14.7 (3 days; P = 0.13), 14.69 (one week; P = 0.15), 14.04 (one month; P = 0.35), and 15.11 (3 months; P = 0.07). No major adverse events were reported. LIMITATIONS: A heterogeneous patient population, small sample size, and potential confounders of concurrent variable adjuvant therapies were limitations. Additionally, most patients received both cement augmentation and targeted RFA, making it difficult to distinguish independent analgesic benefits of the therapies. CONCLUSIONS: This study demonstrates that minimally invasive targeted RFA with cement augmentation of spinal metastatic lesions is an effective treatment for patients with VBM. KEY WORDS: Cancer, cancer pain, spinal metastasis, radiofrequency ablation, tumor ablation, cement augmentation.

Low bone turnover and low BMD in Down syndrome: effect of intermittent PTH treatment.

Trisomy 21 affects virtually every organ system and results in the complex clinical presentation of Down syndrome (DS). Patterns of differences are now being recognized as patients' age and these patterns bring about new opportunities for disease prevention and treatment. Low bone mineral density (BMD) has been reported in many studies of males and females with DS yet the specific effects of trisomy 21 on the skeleton remain poorly defined. Therefore we determined the bone phenotype and measured bone turnover markers in the murine DS model Ts65Dn. Male Ts65Dn DS mice are infertile and display a profound low bone mass phenotype that deteriorates with age. The low bone mass was correlated with significantly decreased osteoblast and osteoclast development, decreased bone biochemical markers, a diminished bone formation rate and reduced mechanical strength. The low bone mass observed in 3 month old Ts65Dn mice was significantly increased after 4 weeks of intermittent PTH treatment. These studies provide novel insight into the cause of the profound bone fragility in DS and identify PTH as a potential anabolic agent in the adult low bone mass DS population.