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Objective: Evaluate outcomes of genicular nerve chemical neurolysis (GChN) in a real-world population with chronic knee pain., Design: Restrospective, observational cohort study., Setting: Tertiary academic medical center., Subjects: Consecutive patients who had undergone GChN ≥3 months prior., Methods: Standardized surveys were collected by telephone and included the numerical rating scale, opioid analgesic use, and Patient Global Impression of Change. Age, sex, body mass index, duration of pain, history of arthroplasty, lack of effect from previous radiofrequency ablation, percentage relief from a prognostic block, and volume of phenol used at each injection site were extracted from charts. Descriptive statistics were calculated, and logistic regression analyses were performed to identify factors influencing treatment outcome., Results: At the time of follow-up after GChN (mean ± SD: 9.9 ± 6.1 months), 43.5% (95% CI = 33.5-54.1) of participants reported ≥50% sustained pain reduction. On the Patient Global Impression of Change assessment, 45.9% (95% CI = 35.5-56.7) of participants reported themselves to be "very much improved" or "much improved." Of 40 participants taking opioids at baseline, 11 (27.5%; 95% CI = 14.6-43.9) ceased use. Of participants with a native knee treated, 46.3% reported ≥50% pain reduction, whereas of participants with an arthroplasty in the treated knee, 33.3% reported this threshold of pain reduction (P = .326). Logistic regression analyses did not reveal associations between treatment success and any of the factors that we evaluated., Conclusions: GChN could provide a robust and durable treatment effect in a subset of individuals with chronic knee pain with complicating factors traditionally associated with poor treatment outcomes, such as those with pain refractory to radiofrequency ablation or those who have undergone arthroplasty., (© The Author(s) 2023. Published by Oxford University Press on behalf of the American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Purpose: To evaluate the differences in radiation dosimetry, fluoroscopy time and procedure time between fluoroscopy-guided chemical and thermal genicular neurolysis techniques., Methods: This single-site, open label observational cohort was done at an urban, tertiary medical center pain clinic. Board certified pain medicine physicians with at least 5 years of experience with genicular neurolysis procedures performed or supervised all interventions. Clinical characteristics and procedural details were collected at each procedure. Patients underwent chemical neurolysis using phenol or cooled radiofrequency neurolysis. Radiation dosimetry was the primary outcome and was compared between the between chemical and radiofrequency neurolysis groups., Results: Thirty-one subjects (15 had chemical and 16 had radiofrequency neurolysis procedures) underwent a total of 43 interventions. Twelve underwent bilateral procedures. Radiation dosimetry per procedure was 1.66 (0.89 to 2.45) Gy-cm 2 for chemical and 1.76 (1.08 to 2.28) Gy-cm 2 for radiofrequency neurolysis, adjusted mean difference -0.092 (-0.60 to 1.114, P  ​= ​0.864) Gy-cm 2 . Procedure times were shorter for chemical compared to radiofrequency neurolysis procedures, difference 9.2 (95% CI 6.8 to 11.6, P  ​< ​0.001) minutes; but no between treatment group differences in fluoroscopy time or interventionalist radiation exposure were observed. Higher BMI and advanced Kellgren-Lawrence grades were associated with increased patient radiation dosimetry., Conclusions: We found that patient radiation dose, fluoroscopy time, and interventionalist radiation exposure were not different between chemical and radiofrequency neurolysis. Genicular neurolysis was more rapidly performed using chemical as compared to radiofrequency neurolysis. BMI and Kellgren-Lawrence grade, but not procedural factors were associated with greater absorbed radiation doses., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2022 The Authors.)

Abstract: The objective was to determine the effectiveness of fluoroscopically guided genicular nerve radiofrequency ablation for painful knee osteoarthritis. Primary outcome measure was improvement in pain after 6 mos. Secondary outcomes included the Oxford Knee Score and Western Ontario and McMaster Universities Osteoarthritis Index. Two reviewers independently assessed publications before October 10, 2020. The Cochrane Risk of Bias Tool and Grades of Recommendation, Assessment, Development, and Evaluation system were used. One hundred ninety-nine publications were screened, and nine were included. Six-month success rates for 50% or greater pain relief after radiofrequency ablation ranged from 49% to 74%. When compared with intra-articular steroid injection, the probability of success was 4.5 times higher for radiofrequency ablation (relative risk = 4.58 [95% confidence interval = 2.61-8.04]). When radiofrequency ablation was compared with hyaluronic acid injection, the probability of treatment success was 1.8 times higher (relative risk = 1.88, 95% confidence interval = 1.38-2.57). The group mean Oxford Knee Score and Western Ontario and McMaster Universities Osteoarthritis Index scores improved in participants receiving genicular radiofrequency ablation compared with intra-articular steroid injection and hyaluronic acid injection. According to Grades of Recommendation, Assessment, Development, and Evaluation, there is moderate-quality evidence that fluoroscopically guided genicular radiofrequency ablation is effective for reducing pain associated with knee osteoarthritis at minimum of 6 mos. Further research is likely to have an important impact on the current understanding of the long-term effectiveness of this treatment., Competing Interests: Financial disclosure statements have been obtained, and no conflicts of interest have been reported by the authors or by any individuals in control of the content of this article., (Copyright © 2021 Wolters Kluwer Health, Inc. All rights reserved.)

Objectives: Implantable pulse generator (IPG) site pain following neuromodulation procedures is a recognized complication. The site of the IPG placement varies depending on the neuromodulation type and physician preference. The incidence of IPG site pain as a function of the site of IPG implantation has not been studied systematically., Materials and Methods: We performed a multicenter cross-sectional survey of the incidence, severity, and quality of IPG site pain, location of the IPG, the pain management needs, functional impairment, and cosmetic appearance related to the IPG placement. Contingency table analysis was conducted for categorical variables, and logistic regression analysis and linear regression model was used., Results: The survey response rate was 60.5% (n = 510). Overall, 31.0% of patients reported pain at the IPG site in the last 72 hours with 31.4% reporting moderate to severe pain and 7.6% reporting severe pain. Older age was inversely associated with IPG-related pain (OR = 0.97, 95% CI = 0.96-0.99, p = 0.001). IPG implantation site did not have a statistically significant interaction with IPG site pain (p > 0.05). The most important factor for IPG site-associated pain was having a spinal cord stimulator implanted as compared to a deep brain stimulator, or sacral nerve stimulator. Most subjects reported no functional impairment related to IPG site pain (91%), found the IPG site pain as expected (80%), and found IPG site cosmetic appearance as expected (96%)., Conclusions: The incidence of IPG site pain is an important complication of invasive neuromodulation. The anatomic location of the IPG placement does not appear to affect the incidence or severity of IPG site pain. However, the presence of a pre-implant chronic pain disorder does appear to affect the frequency and severity of IPG site pain., (© 2020 International Neuromodulation Society.)

Genicular nerve radiofrequency ablation has emerged as a treatment option for patients with painful knee osteoarthritis who have failed conservative management but who may not qualify or wish to avoid a surgical procedure. Radiofrequency ablation techniques targeting the genicular nerves have evolved as our understanding of the anatomy of the anterior knee joint capsule has become more defined. The article aims to review the basic anatomy of the anterior knee joint and both the traditional and revised approaches to nerve ablation., Competing Interests: Competing interests: None declared., (© American Society of Regional Anesthesia & Pain Medicine 2021. No commercial re-use. See rights and permissions. Published by BMJ.)

Objective: Vasomotor symptoms (VMS), sleep disturbance, and cognitive complaints are common among women with a history of breast cancer and contribute to decreased quality of life. Studies in healthy women showed an association between verbal memory performance and physiologic VMS measured with ambulatory skin conductance monitors but not with VMS by self-report. We hypothesized that we would find a similar association in women with breast cancer., Methods: Participants included 30 female breast cancer survivors (mean age 52.7 y; 26.7% African-American) with moderate-to-severe VMS enrolled in a larger clinical trial of a nonhormonal intervention for VMS. At baseline, participants completed assessments of physiologic VMS, actigraphy-based assessments of sleep, questionnaires about mood, and two tests of verbal memory - Logical Memory (LM) and the California Verbal Learning Test (CVLT). Using baseline data, we conducted multivariate regression analyses to examine the association between VMS and memory, controlling for sleep and other factors., Results: On average, women reported 46% of total physiologic VMS. A higher frequency of physiologic VMS - but not reported VMS - was significantly associated with lower scores on the California Verbal Learning Test short-delay free recall (r[28] = -0.41, P = 0.03), long-delay free recall (r[28] = -0.42, P = 0.03), and total clustering, (r[28] = -0.39, P = 0.04). These associations were independent of sleep, mood, and other factors., Conclusions: Independent of their effect on sleep, VMS may be a modifiable contributor to memory difficulties in women with breast cancer. These findings underscore the importance of objective measurement of VMS in cognitive studies. : Video Summary:http://links.lww.com/MENO/A623.

Background: Low-dose lidocaine is a common diluent for analgesia following cervical interlaminar epidural steroid injection (CIESI). Concerns with this practice exist. A single-arm cohort reported that 20% of patients develop postprocedural upper extremity weakness when using lidocaine as a diluent. Furthermore, a high-cervical spinal block with unintended intrathecal or subdural administration is possible., Objective: Determine if low-dose lidocaine as a diluent during CIESI causes clinically meaningful (1) upper extremity weakness and (2) immediate pain relief when compared with saline., Design: Double-blinded randomized control trial., Methods: Patients with cervical radicular pain scheduled for CIESI were enrolled. Participants received lidocaine (CIESI-L) or saline (CIESI-S) as a diluent for the epidural injectate. Myotomal strength was measured with dynamometry before and between 20 and 30 min after CIESI. Pre-pain and post-pain scores were obtained. Primary and secondary outcomes were post-CIESI weakness of ≥20% (minimal clinically important difference (MCID)) in > 1 myotome and ≥50% pain reduction on the numerical scale., Results: 120 participants (64 females (53%), mean age, 56 (SD 13.7) years) completed the study and were analyzed (CIESI-L n=60; CIESI-S n=60). There was no significant between-group difference in the proportion of participants with postprocedural weakness, CIESI-L 41.7% (95% CI, 29.8% to 54.5%), CIESL-S 50% (95% CI, 37.5% to 62.5%). Between-group comparison showed no significant difference in pain reduction, relative risk 1.53 (95% CI, 0.82 to 2.86)., Conclusion: Low-dose lidocaine as a diluent in CIESI does not significantly increase the risk of post-CIESI myotomal weakness when compared with saline, but also does not substantially increase the likelihood of immediate, meaningful pain relief., Trial Registration Details: ClinicalTrials.gov (NCT03127137); December 26, 2017., Competing Interests: Competing interests: ZM and MD serve on the Board of Directors of the Spine Intervention Society., (© American Society of Regional Anesthesia & Pain Medicine 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

Introduction: Moderate sedation (MS) during cryoballoon ablation (CBA) avoids risks of general anesthesia (GA) and improves electrophysiology (EP) lab throughput. However, one barrier to the use of MS is the potential for patient discomfort. The objective of this study was to compare patient-reported outcome measures following CBA for paroxysmal atrial fibrillation (pAF) under MS and GA., Methods and Results: Consecutive patients undergoing a first CBA for pAF under GA or MS were prospectively enrolled. The sedation method was assigned based on patient and provider preference, and perceived airway risk. The primary outcomes were quality of recovery (measured using a validated 40 question survey; QoR-40) and likelihood to recommend (LTR) the procedure and sedation method (measured by Likert scale). Secondary outcomes were acute pulmonary vein (PV) isolation rate, procedure, fluoroscopy and ablation times, and complication rates. Forty-seven GA and 53 MS patients were included. The mean age was 64.9 ± 9.4 years and mean CHA 2 DS 2 -VASc score was 2.0 ± 1.4. QoR-40 scores were 184.6 ± 16.4 for GA and 187.6 ± 10.2 for MS (P = .28). LTR responses were similar between groups. Mean procedure times were 148.2 ± 56.0 minutes for GA and 129.4 ± 31.4 minutes for MS (P = .038). Fluoroscopy and ablation times were similar between groups. A total of 100% (409/409) of PVs were acutely isolated. One hemopericardium occurred in the MS group requiring pericardiocentesis., Conclusion: MS for CBA offers an alternative to GA that is safe and well-tolerated by patients with comparable success rates and improved EP lab throughput., (© 2020 Wiley Periodicals LLC.)

We describe a patient with an intrathecal drug delivery system (IDDS) for management of chronic back pain who developed worsening pain symptoms associated with an infected catheter tip, identified years after initial implantation. A 72-year-old woman had an IDDS initially implanted for management of chronic back pain. Years later, after suffering a vertebral compression fracture, workup revealed magnetic resonance imaging (MRI) findings suggestive of infection despite unremarkable laboratory findings. Her pain worsened, and after explantation of the IDDS, methicillin-resistant Staphylococcus aureus colonized the catheter tip. Worsening pain symptoms in a patient with intrathecal morphine pump must be met with a broad differential diagnosis.

neuECG, the simultaneous noninvasive recording of ECG and skin sympathetic nerve activity (SKNA), directly records sympathetic nerve activity over a long period of time. It can be used to measure sympathetic tone in healthy subjects and in subjects with non-cardiovascular diseases. The electrical activity that can be measured on the surface of the skin originates from the heart, the muscle or nerve structures. Because the frequency content of nerve activity falls in a higher frequency range than that of the ECG and myopotential, it is possible to use high-pass or band-pass filtering to specifically isolate the SKNA. neuECG is voltage calibrated and does not require invasive procedures to impale electrodes in nerves and thus has advantages over microneurography. Here, we present a protocol that takes <10 min to set up. The neuECG can be continuously recorded over a 24-h period or longer. We also describe methods to efficiently analyze neuECG from humans using commercially available hardware and software to facilitate adoption of this technology in clinical research.

Quebec platelet disorder (QPD) is a condition that causes delayed-onset bleeding after hemostatic challenges. While there are interventional spine procedure (ISP) guidelines for managing patients on blood thinners or with common bleeding disorders, there are none for approaching patients with unique coagulopathies. We report a patient with QPD and extensive history of postprocedural bleeding complications (PPBCs) who presented with chronic cervical facet pain. After consulting a hematologist and administering antifibrinolytic agent with platelet transfusions, the patient underwent medial branch nerve blocks (MBNBs) followed by radiofrequency ablation (RFA) without experiencing PPBCs. A comprehensive team approach is critical to maximize patient safety when performing an ISP in such a population.

Background: Fluoroscopically guided cooled genicular nerve radiofrequency ablation (RFA) is an increasingly performed procedure for chronic, refractory knee pain due to osteoarthritis. Traditionally, partial sensory denervation has been accomplished through ablation of the superomedial, superolateral, and inferomedial genicular nerves. However, recent cadaveric studies have demonstrated additional sensory nerves and significant anatomic variation that impact current protocols., Objective: We describe an updated cooled genicular nerve radiofrequency ablation protocol that accounts for varied nerve location of the superomedial, superolateral, and inferomedial genicular nerves, as well as capture of the terminal articular branches of the nerves to the vastus intermedius, vastus lateralis, and vastus medialis. Furthermore, we describe an adjusted technique for inferomedial genicular nerve capture that mitigates the risk of pes anserine tendon injury., Design: Technical report and brief literature review., Methods: Cadaveric studies relating to the sensory innervation of the anterior knee joint were reviewed, and a more accurate and comprehensive cooled genicular nerve radiofrequency ablation (CRFA) protocol is proposed., Conclusions: Based on recent, rigorous anatomic dissections of the knee, the proposed genicular nerve CRFA protocol will provide more complete sensory denervation and potentially improve clinical outcomes. Prospective studies will be needed to confirm the hypothesis that this protocol will result in improved effectiveness and safety of genicular nerve RFA., (© 2019 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Study Design: Retrospective matched cohort study., Objective: To determine if low-pressure lumbar provocation discography (PD) results in long-term accelerated disc degeneration, internal disc disruption, or disc herniation in patients with symptomatic low back pain (LBP)., Summary of Background Data: Study of subjects without clinically-significant LBP suggests that high-pressure PD may accelerate disc degeneration., Methods: Consecutive patients with symptomatic LBP who underwent magnetic resonance imaging (MRI), PD, and repeat MRI more than 7 years later, but did not undergo subsequent spinal fusion surgery, were included. Punctured discs were matched (1:2 to 1:4) to corresponding discs in a control cohort by age, BMI, Pfirrmann score (±2), and presence of disc herniation; control cohort inclusion required MRIs for symptomatic LBP, separated by more than 7 years. The primary outcome of the study was a progression in Pfirrmann score category (I-II, III-IV, V). MRI disc-to-CSF T2 signal-intensity ratio, disc height, disc herniations, high intensity zones (HIZs), and Modic changes were assessed., Results: Baseline and follow-up MRIs were available for 77 discs exposed to PD, and for 260 discs in the matched control cohort. There was no difference in the proportion of punctured discs that advanced in Pfirrmann score category in the PD group (17%, 95% CI 9-27%) compared with corresponding discs in the Control group (21%, 95% CI 17-27%), P = 0.3578, or in non-punctured discs in the PD group (35%, 95% CI 21-51%) compared with corresponding discs in the Control group (34%, 95% CI 27-42%), P = 0.1169. There were no differences in disc-to-CSF T2 signal-intensity ratio, presence of disc herniations, HIZs, or Modic changes following puncture in the PD versus matched cohort discs or in the non-punctured PD cohort discs versus corresponding control cohort discs (P > 0.05)., Conclusion: Patients with symptomatic LBP who underwent low-pressure PD, but who did not undergo a subsequent spinal fusion surgery, developed disc degeneration and new disc herniations at a similar rate to corresponding discs in matched control patients., Level of Evidence: 3.

Background and Objectives: No previous study has assessed the outcomes of cooled radiofrequency ablation (C-RFA) of the medial branch nerves (MBN) for the treatment of lumbar facet joint pain nor compared its effectiveness with traditional RFA (T-RFA). This study evaluated 6-month outcomes for pain, function, psychometrics, and medication usage in patients who underwent MBN C-RFA versus T-RFA for lumbar Z-joint pain., Methods: In this blinded, prospective trial, patients with positive diagnostic MBN blocks (>75% relief) were randomized to MBN C-RFA or T-RFA. The primary outcome was the proportion of 'responders' (≥50% Numeric Rating Scale (NRS) reduction) at 6 months. Secondary outcomes included NRS, Oswestry Disability Index (ODI), and Patient Global Impression of Change., Results: Forty-three participants were randomized to MBN C-RFA (n=21) or T-RFA (n=22). There were no significant differences in demographic variables (p>0.05). A ≥50% NRS reduction was observed in 52% (95% CI 31% to 74%) and 44% (95% CI 22% to 69%) of participants in the C-RFA and T-RFA groups, respectively (p=0.75). A ≥15-point or ≥30% reduction in ODI score was observed in 62% (95% CI 38% to 82%) and 44% (95% CI 22% to 69%) of participants in the C-RFA and T-RFA groups, respectively (p=0.21)., Conclusions: When using a single diagnostic block paradigm with a threshold of >75% pain reduction, both treatment with both C-RFA and T-RFA resulted in a success rate of approximately 50% when defined by both improvement in pain and physical function at 6-month follow-up. While the success rate was higher in the C-RFA group, this difference was not statistically significant., Trial Registration Number: NCT02478437., Competing Interests: Competing interests: ZLMcC serves on the board of directors for the Spine Intervention Society. The authors otherwise declare no potential conflicts of interest., (© American Society of Regional Anesthesia & Pain Medicine 2019. No commercial re-use. See rights and permissions. Published by BMJ.)

Background and Objectives: Genicular nerve radiofrequency ablation is an effective treatment for patients with chronic pain due to knee osteoarthritis; however, little is known about factors that predict procedure success. The current study evaluated the utility of genicular nerve blocks to predict the outcome of genicular nerve cooled radiofrequency ablation (cRFA) in patients with osteoarthritis., Methods: This randomized comparative trial included patients with chronic knee pain due to osteoarthritis. Participants were randomized to receive a genicular nerve block or no block prior to cRFA. Patients receiving a prognostic block that demonstrated ≥50% pain relief for six hours received cRFA. The primary outcome was the proportion of participants with ≥50% reduction in knee pain at six months., Results: Twenty-nine participants (36 knees) had cRFA following a prognostic block, and 25 patients (35 knees) had cRFA without a block. Seventeen participants (58.6%) in the prognostic block group and 16 (64.0%) in the no block group had ≥50% pain relief at six months (P = 0.34). A 15-point decrease in the Western Ontario and McMaster Universities Osteoarthritis Index at six months was present in 17 of 29 (55.2%) in the prognostic block group and 15 of 25 (60%) in the no block group (P = 0.36)., Conclusions: This study demonstrated clinically meaningful improvements in pain and physical function up to six months following cRFA. A prognostic genicular nerve block using a local anesthetic volume of 1 mL at each injection site and a threshold of ≥ 50% pain relief for subsequent cRFA eligibility did not improve the rate of treatment success.

Surgical-site infection, spinal cord abscess, and catheter tip granuloma are known but rare complications of intrathecal drug delivery systems (IDDS). To date, there are no published cases of brain abscess in a patient with an IDDS. In this study, we report a case of a cancer patient with an IDDS for management of cancer pain who developed a brain abscess with profound mental status changes and clinical management challenges.

Objective: Low-dose local anesthetic is often used in cervical interlaminar epidural steroid injections (CIESI), yet its effect on upper extremity strength has not been studied. The presence of consequent weakness has potential implications for postprocedure safety. This study aimed to determine whether low-dose lidocaine in a C7-T1 CIESI causes objective weakness., Design: Prospective case series., Setting: Academic pain center., Subjects: Adults, cervical radicular pain., Methods: Participants underwent CIESI with 1 mL of 1% lidocaine (3 mL total injectate). Elbow flexion (EF), wrist extension (WE), elbow extension (EE), and handgrip strength were measured by dynamometry at baseline, 15 minutes, and 30 minutes postinjection. Changes in strength from baseline and the proportion of participants with a minimum perceptible change in EF, WE, EE, and handgrip strength (≥20%) and 95% confidence intervals (CIs) were calculated., Results: Twenty-seven participants were included. At 15 and 30 minutes postinjection, there was no within-participant difference in EF, WE, EE, and handgrip strength from baseline overall. Nonetheless, five (19%, 95% CI = 4-33) of the participants demonstrated a 20% or greater strength decrease in at least one myotomal distribution. A 20% or greater decrease in strength was present in left EF 4% (95% CI = 0-11%), right EF 7% (95% CI = 0-17%), left WE 4% (95% CI = 0-11%), and right WE 7% (95% CI = 0-17%)., Conclusions: The present data suggest that CIESI with an injectate volume of 3 mL that includes 1 mL of 1% lidocaine may result in objective upper extremity weakness that is above the minimum threshold of perception in a subset of patients., (© 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Objective: Determine outcomes of cooled radiofrequency ablation (C-RFA) of the genicular nerves for treatment of chronic knee pain due to osteoarthritis (OA)., Design: Cross-sectional survey., Setting: Academic pain medicine center., Subjects: Consecutive patients with knee OA and 50% or greater pain relief following genicular nerve blocks who underwent genicular nerve C-RFA., Methods: Survey administration six or more months after C-RFA. Pain numeric rating scale (NRS), Medication Quantification Scale III (MQSIII), Patient Global Impression of Change (PGIC), and total knee arthroplasty (TKA) data were collected. Logistic regression was used to identify factors that predicted treatment success., Results: Thirty-three patients (52 discrete knees) met inclusion criteria. Thirty-five percent (95% confidence interval [CI] = 22-48) of procedures resulted in the combined outcome of 50% or greater reduction in NRS score, reduction of 3.4 or more points in MQSIII score, and PGIC score consistent with "very much improved/improved." Nineteen percent (95% CI = 10-33) of procedures resulted in complete pain relief. Greater duration of pain and greater than 80% pain relief from diagnostic blocks were identified as predictors of treatment success. The accuracy of the model was 0.88 (95% CI = 0.78-0.97, P  <   0.001)., Conclusions: Genicular C-RFA demonstrated a success rate of 35% based on a robust combination of outcome measures, and 19% of procedures resulted in complete relief of pain at a minimum of six months of follow-up. Report of 80% or greater relief from diagnostic blocks and duration of pain of less than five years are associated with high accuracy in predicting treatment success. Further prospective study is needed to optimize the patient selection protocol and success rate of this procedure., (© 2017 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Objectives: Spinal cord stimulation is an evidence-based treatment for a number of chronic pain conditions. While this therapy offers improvement in pain and function it is not without potential complications. These complications include device failure, migration, loss of therapeutic paresthesia, and infection. This article looked to establish a modern infection rate for spinal cord stimulators, assess the impact of known risk factors for surgical site infections and to determine the impact of certain preventative measures on the rate of infection., Methods: After institutional review board approval, a multisite, retrospective review was conducted on 2737 unique implants or revisions of SCS systems. Patient demographics, risk factors including diabetes, tobacco use, obesity, revision surgery, trial length, implant location, implant type, surgeon background, prophylactic antibiotic use, utilization of a occlusive dressing, and post-operative antibiotic use were recorded and analyzed., Results: The overall infection rate was 2.45% (n = 67). Diabetes, tobacco use, and obesity did not independently increase the rate of infection. Revision surgeries had a trend toward higher infection rate; however, this did not meet statistical significance. There was no difference in the rate of infection between implants performed by physicians of different base specialties, cylinder leads vs. paddle leads, or between different prophylactic antibiotics. Implants performed at academic centers had a higher rate of infection when compared to implants performed in nonacademic settings. When patients received an occlusive dressing or post-operative antibiotics they had a lower rate of infection., Conclusions: The infection rate (2.45%) reported in this study is lower than the previously reported rates (3-6%) and are on par with other surgical specialties. This study did not show an increased rate of infection for patients that used tobacco, had diabetes or were obese. It's possible that given the low overall infection rate a larger study is needed to establish the true impact of these factors on infection. In addition, this study did not address the impact of poorly controlled diabetes mellitus (elevated hemoglobin A1c) vs. well-controlled diabetes. It can be concluded from this study that utilizing an occlusive dressing over the incision in the post-operative period decreases the rate of infection and should become the standard of care. This study also demonstrated the positive impact of post-operative antibiotics in decreasing the rate of infection. Studies in other surgical specialties have not shown this impact which would suggest that further research is needed., (© 2017 International Neuromodulation Society.)

Introduction: Surgical site infection is a potential complication of spinal cord stimulator (SCS) implantation. Current understanding of the epidemiology, diagnosis, and treatment of these infections is based largely on small clinical studies, many of which are outdated. Evidence-based guidelines for management of SCS-related infections thus rely instead on expert opinion, case reports, and case series. In this study, we aim to provide a large scale retrospective study of infection management techniques specifically for SCS implantation., Methods: A multicenter retrospective study of SCS implants performed over a seven-year period at 11 unique academic and non-academic institutions in the United States. All infections and related complications in this cohort were analyzed., Results: Within our study of 2737 SCS implant procedures, we identified all procedures complicated by infection (2.45%). Localized incisional pain and wound erythema were the most common presenting signs. Laboratory studies were performed in the majority of patients, but an imaging study was performed in less than half of these patients. The most common causative organism was Staphylococcus aureus and the IPG pocket was the most common site of an SCS-related infection. Explantation was ultimately performed in 52 of the 67 patients (77.6%). Non-explantation salvage therapy was attempted in 24 patients and was successful in resolving the infection in 15 patients without removal of SCS hardware components., Discussion: This study provides current data regarding SCS related infections, including incidence, diagnosis, and treatment., (© 2017 International Neuromodulation Society.)

Background: Higher body mass index (BMI) is associated with difficulty in obtaining imaging studies. While there is a small body of literature regarding the relationship between fluoroscopy time and BMI during injections for pain management, this has not been studied for intraarticular (IA) hip injections. Further, in academic training centers, trainee involvement may affect this relationship., Objective: To determine the relationship between BMI and fluoroscopy time during IA hip injections, both with and without involvement of a trainee., Study Design: Multicenter retrospective cohort study., Setting: Three academic, outpatient musculoskeletal and pain medicine centers., Methods: Patients who underwent fluoroscopically guided IA hip injections with encounter data regarding fluoroscopy time during the procedure and BMI were included. Mean and standard deviation fluoroscopy time were recorded. Comparisons were made between BMI categories of normal (18.5 - 24.9 kg/m2), overweight (25.0 - 29.9 kg/m2), and obese (greater than or equal to30.0 kg/m2). Statistical significance was set at P = 0.01 due to multiple comparisons., Results: A total of 559 IA hip injections are represented in this cohort. Patients had a mean age of 58 (standard deviation [SD] 14) years and 63% were women. There was no significant difference in fluoroscopy time when comparing BMI categories (P = 0.02). However, when trainees were not involved in the injection, fluoroscopy times were significantly shorter with decreasing BMI category, with normal weight patients requiring the shortest fluoroscopy times (P = 0.01)., Limitations: This study evaluated total fluoroscopy time, not radiation dose exposure per injection, which provides more direct and precise information with regard to provider and patient radiation exposure and overall safety. Future study of the impact of BMI on radiation dose during fluoroscopically guided IA hip injections is needed., Conclusions: Fluoroscopy times during IA hip injections increase with higher BMI categories in a statistically significant manner when performed by experienced clinicians but this relationship is not observed when injections are performed with a trainee in a teaching institution. This finding appears to be related to longer fluoroscopy time required to complete an IA hip injection in patients with lower BMI when a trainee is involved., Key Words: Hip, injections, obesity, overweight, body mass index, fluoroscopy, radiation, pain.

Background: The challenge of obtaining medical imaging in individuals with higher body mass index (BMI) is described, but there is minimal data regarding the relationship between BMI and fluoroscopy time during cervical interlaminar epidural steroid injection (CIESI)., Objective: To determine the relationship between BMI and fluoroscopy time during CIESI., Methods: Retrospective cohort study of patients who underwent fluoroscopically guided CIESI between January 2014 and February 2015 at an academic pain medicine center. Fluoroscopy time data were collected. Comparisons based on analysis of variance were made between patients with normal (<25.0 kg/m 2 ), overweight (25.0-29.9 kg/m 2 ), and obese (≥30.0 kg/m 2 ) BMI., Results: Of 399 procedure encounters, 366 had documented BMI and fluoroscopy time data and were included for analysis. Mean age (± SD) in this cohort was 53 ± 13 years, including 189 females (52%) and 205 first-time injections. Mean fluoroscopy time for all injections was 18 ± 10 seconds. Separated by categorical BMI class, the mean fluoroscopy time was 18 ± 9 seconds for normal weight patients, 17 ± 10 seconds for overweight patients, and 20 ± 11 seconds for obese patients, respectively. Post hoc analysis showed that fluoroscopy time was significantly longer only in obese compared with overweight patients ( P  = 0.02). Trainee involvement and first-time vs repeat injection did not significantly alter fluoroscopy time ( P  = 0.17 and P  = 0.12, respectively)., Conclusions: The findings of this study indicate that BMI does not appear to have a clinically significant impact on fluoroscopy time during cervical interlaminar epidural steroid injection procedures. Future study is needed to directly quantify radiation exposure in patients and practitioners, as well as the associated health risk., (© 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com)

Objective: This study aimed to assess the relationship between BMI and fluoroscopy time during lumbar epidural steroid injections (LESIs) performed for lumbosacral radicular pain., Design: Multicenter retrospective cohort study., Setting: Three academic, outpatient pain treatment centers., Subjects: Patients who underwent fluoroscopically guided LESI., Methods: Mean and standard deviation (SD) fluoroscopy time were compared between patients with normal (18.5-24.9 kg/m2), overweight (25.0-29.9 kg/m2), and obese (≥30.0 kg/m2) BMI. Statistical significance was set at P=0.01 due to multiple comparisons., Results: A total of 2,930 procedure encounters were included, consisting of 598 interlaminar LESIs and 2,332 transforaminal LESIs. Fluoroscopy time was significantly longer in the obese patients compared to normal and overweight patients during interlaminar LESI (P < 0.01). Fluoroscopy time was significantly longer with each increasing BMI category in during transforaminal LESI (P < 0.01). These relationships remained when a trainee was involved (P < 0.01; P<0.01), during repeat injections (P < 0.01; P < 0.01), and during bilateral transforaminal LESIs (P < 0.01). While longer fluoroscopy times were required in high BMI categories during L5-S1 transforaminal LESI (P < 0.01), there was no relationship between fluoroscopy time and BMI during L4-L5 and S1 transforaminal LESI (P = 0.02; P = 0.13). Fluoroscopy time during interlaminar LESI compared to transforaminal LESI was significantly lower within all BMI categories (all P<0.01)., Conclusions: The findings of this study indicate that fluoroscopy time is increased during interlaminar LESIs and during L5-S1 transforaminal LESIs in patients who are obese. These relationships are not affected by injection number, performance of bilateral injections, or trainee involvement. Further study is needed to determine if this increase in fluoroscopy time is indicative of a clinically significant associated increase in radiation dose., (© 2016 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Background and Objectives: No study has compared cervical interlaminar epidural steroid injection (CIESI) with epidural catheter advancement to the side and level of pathology versus standard C7-T1 CIESI. This study investigated whether cervical radicular pain is more effectively treated by CIESI with a targeted epidural catheter versus a standard C7-T1 approach., Methods: Prospective, randomized, single-blinded trial., Primary Outcome: Numerical Rating Scale (NRS) pain at 1 month., Secondary Outcomes: Oswestry Neck Disability Index (ONDI), Pain Disability Index (PDI), McGill Pain Questionnaire (MPQ), Patient Global Impression of Change (PGIC), daily morphine equivalents (DME), and Medication Quantification Scale (MQS) III scores., Results: Seventy-six participants with a median age of 48 years (IQR, 40-56 years), 59% female, with C4 (n = 2), C5 (n = 27), or C6 (n = 47) radicular pain were enrolled. At 1 month in the catheter and no catheter groups, respectively: 26 (72%, 95% confidence interval [CI], 57%-87%) and 23 (60%; 95% CI, 45%-75%) participants reported 50% or greater NRS reduction; 24 (67%; 95% CI, 52%-84%) and 23 (58%; 95% CI, 42%-73%) participants reported 30% or greater ONDI reduction. There were no group differences in median NRS, ONDI, PDI, MPQ, PGIC, DME, or MQSIII scores (P > 0.05). Intergroup differences were not observed at any follow-up interval., Conclusions: This trial showed no significant difference in clinical outcomes with CIESI using a targeted epidural catheter compared to a standard C7-T1 approach for the treatment of unilateral cervical radicular pain at the C5 or C6 level. Both techniques were associated with clinically meaningful improvement across outcome domains of pain, function, disability, and medication use. These effects persisted to 6-month follow-up.The study was registered at Clinical Trials.gov (NCT02095197).

Background: The corticosteroid choice for a lumbar transforaminal epidural steroid injection (TFESI) remains controversial. Whether to utilize particulate or nonparticulate steroid preparations for these injections remains an unanswered question in the literature., Objective: To determine if a particulate or nonparticulate steroid is more effective in the treatment of electromyography (EMG)-confirmed lumbosacral radiculopathy., Design: Multicenter retrospective cohort study., Setting: Two tertiary academic spine centers., Patients: Consecutive patients, aged 18 years or older, with EMG-confirmed lumbosacral radiculopathy., Interventions: TFESI with a particulate or nonparticulate steroid to treat radicular pain within 6 months of EMG., Main Outcome Measures: The primary outcome was the proportion of patients with ≥50% pain reduction on the numerical rating scale after TFESI. Secondary outcomes included mean numerical rating scale score reduction and number of repeat TFESIs. Short-term (<30 days) and intermediate (≥30 days) outcomes were compared between patients who received a TFESI with a particulate versus nonparticulate steroid., Results: Seventy-eight patients, with an age ± standard deviation of 56 ± 16 years and a mean symptom duration of 49 ± 71 months, were included. Forty-one patients (52%) received dexamethasone, 23 (30%) received triamcinolone, and 14 (18%) received betamethasone. There was no statistically significant difference in the proportion of patients who reported ≥50% pain reduction between the particulate and nonparticulate groups at short-term follow-up (35%; 95% confidence interval [CI], 21-51 versus 28%; 95% CI, 13-43) or at intermediate follow-up (40%; 95% CI, 21-59 versus 39%; 95% CI, 19-59). There was no difference in the mean number of injections administered between groups at intermediate follow-up (P = .26)., Conclusions: This study demonstrates no significant differences in pain reduction or the number of repeat injections with particulate compared with nonparticulate transforaminal epidural steroid injection in patients with EMG-confirmed painful lumbosacral radiculopathy. These findings suggest a new population for whom nonparticulate steroid appears to be an appropriate first-line therapy, although confirmation with a randomized study is needed., Level of Evidence: III., (Copyright © 2016 American Academy of Physical Medicine and Rehabilitation. Published by Elsevier Inc. All rights reserved.)

Objectives: In a pilot randomized clinical trial of active stellate ganglion blockade (SGB) versus sham control, SGB significantly reduced the frequency of reported moderate to severe vasomotor symptoms (VMS) and the frequency of physiologic VMS measured using ambulatory skin conductance monitors. Here we examine secondary effects of SGB on verbal learning and memory., Study Design: In a randomized, sham-controlled study, 36 women met eligibility criteria for cognitive assessments, of whom 17 were randomized to receive fluoroscopy-guided SGB and 19 to sham control., Main Outcome Measures: At baseline and three months post-treatment, women completed tests of verbal learning and memory (primary outcome) and other cognitive measures and also wore an ambulatory monitor for 24h to measure physiologic VMS and VMS reported in real time., Results: Verbal learning improved following active SGB (p<0.05) but not sham treatment; however, the interaction between group and time was not significant (p values 0.13-0.20). Two secondary cognitive measures improved only in the sham group. Improvements in physiologic VMS correlated significantly with improvements in verbal learning (r=0.51, p<0.05)., Conclusions: SGB might confer benefits to memory in relation to the magnitude of improvement in physiologic VMS. Broadly these findings suggest a possible link between physiologic VMS and memory problems in midlife women., (Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.)

Background: Chronic knee pain from osteoarthritis (OA) is common in the aging and the obese population. Radiofrequency ablation of the genicular nerves has been introduced as a potential surgery-sparing treatment for chronic knee pain from OA, yet only two outcome studies have been published and optimal patient selection for this procedure has not been established., Objectives: We describe a standardized protocol for selecting patients for cooled radiofrequency ablation (C-RFA) of the genicular nerves, as well as the clinical outcomes of four patients ages 63-65 years., Methods: The threshold for selection based on diagnostic genicular nerve block was ≥ 80% pain reduction. Following successful block, C-RFA of the genicular nerves was performed. Outcomes included pain, function, analgesic medication use, opioid use, and progression to total knee arthroplasty at a minimum of 6 month follow up., Results: C-RFA of the genicular nerves after using the described selection protocol resulted in > 90% pain reduction, improved function and avoidance of surgery at 6 months in all four cases. All opioid and analgesic medication use decreased or was unchanged in all cases. No serious adverse events occurred., Conclusions: The accompanying case series suggests that this protocol is deserving of randomized, prospective study.

Objective: To determine the relationship between BMI and fluoroscopy time during intra-articular sacroiliac joint (SIJ) injections performed for a pain indication., Design: Multicenter retrospective cohort study., Setting: Three academic, outpatient pain treatment centers., Subjects: Patients who underwent fluoroscopy guided SIJ injection with encounter data regarding fluoroscopy time during the procedure and body mass index (BMI)., Main Outcome Measure: Median and 25-75% Interquartile Range (IQR) fluoroscopy time., Results: 459 SIJ injections (350 patients) were included in this study. Patients had a median age of 57 (IQR 44, 70) years, and 72% were female. The median BMI in the normal weight, overweight, and obese groups were 23 (IQR 21, 24), 27 (IQR 26, 29), and 35 (IQR 32, 40), respectively. There was no significant difference in the median fluoroscopy time recorded between these BMI classes (p = 0.45). First-time SIJ injection (p = 0.53), bilateral injection (p = 0.30), trainee involvement (p = 0.47), and new trainee involvement (trainee participation during the first 2 months of the academic year) (p = 0.85) were not associated with increased fluoroscopy time for any of the three BMI categories., Conclusions: Fluoroscopy time during sacroiliac joint injection is not increased in patients who are overweight or obese, regardless of whether a first-time sacroiliac joint injection was performed, bilateral injections were performed, a trainee was involved, or a new trainee was involved., (© 2015 American Academy of Pain Medicine. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)

Objective: To characterize the incidence, severity, quality, and treatment of pain in a large cohort of Marfan patients., Materials and Methods: A web-based survey was distributed to all individuals on the Marfan Foundation listserv. Respondents who endorsed a diagnosis of Marfan syndrome were queried as to the presence, frequency, severity, location, and quality of their pain and were asked to describe the specific treatments used to manage pain. The primary outcome was the presence of pain symptoms in respondents during the 7-day period preceding completion of the survey., Results: Of the 993 patients with a verified diagnosis of Marfan syndrome, 67% (95% confidence interval, 64%-69%) reported pain in the preceding 7 days. Median (interquartile range) "average daily pain" was 4 (3 to 5) on the numeric rating scale; "worst pain" was 7 (5 to 8). "Worst pain experienced" was ≥4 in 93% of respondents. Analgesic use to control pain related to Marfan syndrome was reported in 56% of respondents with 55% reporting <50% pain relief with this modality. Few patients underwent interventional procedures for pain control, despite intractable back and joint pain being common. A majority (52%) of respondents rated "chronic pain care" from their physicians as either "poor" or "fair.", Discussion: Our findings suggest that pain symptoms in Marfan patients are underestimated and likely undertreated. We propose a need for improved patient and medical provider awareness of pain management options in this population, including the development of effective algorithms to treat pain in Marfan patients.

Objective: Minimal definitive literature identifies patients with radicular pain who would benefit most from epidural steroid injection (ESI). This study investigated if electromyographic (EMG) confirmation of radiculopathy with active or chronic denervation predicts a positive treatment outcome following ESI., Design: Longitudinal cohort study of adults who underwent EMG and subsequent transforaminal ESI within 6 months. The proportion of individuals who experienced >50% pain relief and mean change in daily morphine equivalents (DME) were calculated., Results: 170 individuals with respective mean (Standard Deviation) age and duration of symptoms of 55 (15) years and 36 (56) months were included. Mean time to <30 day and >30 day follow-up post-injection were 18 (6) and 99 (130) days, respectively. At >30 day follow-up, a larger proportion of EMG-confirmed individuals (37.7%) reported >50% pain reduction compared to EMG-negative individuals (17.8%) (p=0.03). This was significant for lumbosacral (40% vs. 15%, p=0.01) but not cervical symptoms (p>0.05). Mean decrease in DME at long-term follow-up in EMG-confirmed compared to EMG-negative individuals trended toward significance (-4 vs. -1, p=0.11). There was no significant relationship between myotomal spontaneous activity and pain or opioid use., Conclusions: Needle EMG predicts long-term pain reduction from transforaminal ESI in patients with lumbosacral radiculopathy, regardless of the presence of active denervation.

Background and Objectives: The lack of studies that identify patient and procedural risk factors for increased levels of anxiety during spine injections represents a major barrier to the development of safe tailored sedation practices. We measured and compared anxiety in procedure-naive patients undergoing a cervical or lumbar interlaminar epidural steroid injection to identify predictors of patient movement and vasovagal responses in the periprocedural period., Methods: This prospective observational cohort study was conducted with injection-naive patients presenting for a routine cervical or lumbar epidural steroid injection. The primary outcome measure was the Spielberger State Trait Anxiety Inventory (STAI) score. Participants also reported anxiety using the Numeric Rating Scale in the periprocedural period. The Wilcoxon rank sum test was used to compare STAI scores; Numeric Rating Scale values were compared using Friedman test. Post hoc tests were corrected for 12 comparisons using the Bonferroni method., Results: We found no group differences in age, gender, marital status, Visual Analog Scale pain score, duration of pain symptoms, or utilization of health care resources for pain symptom management. The mean STAI score was 43 ± 8 in the cervical group (n = 140) and 44 ± 9 in the lumbar group (n = 140) (P = 0.35), a low level of anxiety. There were no between-group differences in anxiety at any point during the periprocedural period. A vasovagal response was identified in 10% of the cervical group and in 3% of the lumbar group (P = 0.04)., Conclusions: No group differences in anxiety were seen between cervical and lumbar groups. Anxiety levels were not associated with patient movement or vasovagal symptoms. Our results suggest that the practice of routine prevention or treatment of injection-related anxiety in the procedure-naive general population with a duration of pain less than 6 months and without a history of an anxiety disorder should be reevaluated.

Somatic tinnitus is a common disorder, yet few treatments described in the literature have demonstrated strong efficacy. We report a case of a 61-year-old male with refractory somatic tinnitus, temporally related to a prior bacterial otitis media, wherein auditory symptoms were successfully treated with cervical epidural injections of long-acting corticosteroid. We discuss the proposed mechanism of somatic tinnitus and the means by which neuraxial steroids may inhibit somatic tinnitus symptoms., (© 2014 World Institute of Pain.)

Objective: Radiofrequency ablation (RFA) of the medial branch nerves for facet-mediated low back pain demonstrates clinical benefit for 6-12 months and possibly up to 2 years. This study investigated function, pain, and medication use outcomes of RFA for lumbar facet syndrome in a cohort with long-term follow-up., Methods: Individuals evaluated in a tertiary academic pain practice between January, 2007-December, 2013, 18-60 years of age, with a clinical and radiologic diagnosis of lumbar facet syndrome, who underwent ≥1set of diagnostic medial branch blocks with resultant >75% pain relief and subsequent RFA were included. Outcomes measured were the proportion of individuals who reported ≥50% improvement in function, ≥50% improvement in pain; change in median NRS pain score, daily morphine equivalent consumption (DME), Medication Quantification Scale III (MSQ III) score and procedure complications., Results: Sixty-two consecutive individuals with a median age and 25%-75% interquartile range (IQR) of 34 years (35, 52) met inclusion criteria. Seven individuals were lost to follow-up. Duration of pain was <2 years in 42%, 2-5 years in 40%, >5 years in 18% of individuals. Median duration of follow-up was 39 months (16, 60). Function and pain improved by ≥50% in 58% (CI 45%, 71%) and 53% (CI 40%, 66%) of individuals, respectively. The median reduction in MQS III score was 3.4 points (0, 8.8). No complications occurred in this cohort., Conclusions: This study demonstrates a durable treatment effect of RFA for lumbar facet syndrome at long-term follow-up, as measured by improvement in function, pain, and analgesic use.

Objective: Uncontrolled intervention studies, including studies involving breast cancer survivors, have demonstrated improvements in vasomotor symptoms (VMS) after stellate ganglion blockade (SGB) with a local anesthetic. This study presents the first randomized sham-controlled trial of SGB for the treatment of VMS., Methods: Participants included 40 postmenopausal women, aged 30 to 70 years, with moderate to severe VMS. The study was a randomized sham-controlled trial comparing the effects of SGB versus sham injection on the frequencies of total and moderate to severe VMS, as measured by daily diaries. Image-guided SGB was performed with 5 mL of 0.5% bupivacaine. Sham injection of saline was performed in subcutaneous tissues in the neck. VMS were recorded at baseline and for 6 months thereafter. Objective VMS were recorded using ambulatory sternal skin conductance monitoring during a 24-hour period at baseline and on 3-month follow-up., Results: There were no significant group differences in overall VMS frequency, but the frequency of moderate to very severe VMS was reduced more in the active group compared with the sham treatment group (event rate ratio, 0.50; 95% CI, 0.35-0.71; P < 0.001). The frequency of objective VMS was also reduced to a greater degree in the SGB group than in the sham group (event rate ratio, 0.71; 95% CI, 0.64-0.99; P < 0.05). There were no study-related serious adverse events., Conclusions: SGB may provide effective treatment of VMS in women who seek nonhormonal treatments because of safety concerns and personal preference. The finding that SGB significantly reduces objectively measured VMS provides further evidence of efficacy. A larger trial is warranted to confirm these findings.

Burning Mouth Syndrome (BMS) is a chronic painful disorder characterized by unremitting bilateral burning oral pain often associated with taste abnormalities and complaints of dry mouth. The diagnosis is made by history and symptom presentation in the absence of an identifiable cause or oral lesion. It is commonly seen in perimenopausal women but is also seen in men, and is considered a small-fiber neuropathy. Management can be challenging and few effective treatments are available. This article presents a case report of stellate ganglion blockade as a treatment for recalcitrant pain from BMS.

Background: While cooled radiofrequency ablation (C-RFA) appears to be a promising technology for joint denervation, outcomes of this technique for the treatment of lumbar facet syndrome have not been described. We report clinical outcomes in a case series of patients treated with C-RFA for lumbar facet syndrome., Methods: Consecutive patients aged 18-60 years diagnosed with lumbar facet syndrome, confirmed by ≥75% symptom relief with at least one set of diagnostic medial branch nerve blocks, who underwent C-RFA between January 2007 and December 2013 in an urban academic pain center were included. The respective proportions of participants who reported ≥50% improvement in pain and in function were calculated. Change in median NRS score, daily morphine equivalent consumption (DME), and medication quantification scale III (MQS III) score were measured., Results: Twelve patients underwent C-RFA; three were lost to follow-up. The median and 25%-75% interquartile range (IQR) for age was 44 years (35, 54). The median duration of follow-up was 34 months, IQR (21, 55). The percentage and 95% confidence interval (CI) of patients who reported ≥50% improvement in pain was 33% CI (12%, 64%) and in function was 78%, CI (41%, 96%). There was no significant change in DME or MSQ III score. Approximately 50% of patients sought additional healthcare by long-term follow-up. No complications were reported., Conclusions: This case series suggests that C-RFA may improve function and to a lesser degree pain at long-term follow-up. A randomized, controlled trial is warranted.

Background Context: Pain innate to intervertebral disc, often referred to as discogenic pain, is suspected by some authors to be the major source of chronic low back and neck pain. Current management of suspected discogenic pain lacks standardized diagnosis, treatment, and terminology., Purpose: In an attempt to determine whether patterns existed that may facilitate standardization of care, we sought to analyze the terminologies used and the various modes of diagnosis and treatment of suspected discogenic pain., Study Design: A systematic review of the recent literature., Methods: A Medline search was performed using the terms degenerative disc disease, discogenic pain, internal disc disruption while using the limits of human studies, English language, and clinical trials, for the last 10 years. The search led to a total of 149 distinct citations, of which 53 articles, where the intervertebral disc itself was considered the principal source of patient's pain and was the main target of the treatment, were retained for further analysis., Results: The results of this review confirm and help quantify the significant differences that existed in the terminology and all the areas of diagnosis and treatment of presumed discogenic pain., Conclusions: Our findings show that suspected discogenic pain, despite its extensive affirmation in the literature and enormous resources regularly devoted to it, currently lacks clear diagnostic criteria and uniform treatment or terminology., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Central nervous system injuries after transforaminal epidural steroid injections have been ascribed to occlusion of the blood vessels supplying the spinal cord and brain by the particulate steroid., Methods: The authors compared the sizes of the particles of the steroids methylprednisolone acetate, triamcinolone acetonide, dexamethasone sodium phosphate, betamethasone sodium phosphate/betamethasone acetate (both Celestone Soluspan; Schering-Plough, Kenilworth, NJ, the commercial betamethasone; and betamethasone repository, a betamethasone preparation that can be ordered from a compounding company), and betamethasone sodium phosphate. Both undiluted and diluted samples were examined. The samples were examined with a laser scanning confocal microscope, and images were analyzed and measured. The particles were categorized (or tabulated) into groups: 0-20, 21-50, 51-1000, and greater than 1000 mu. Chi-square analyses, with Bonferroni correction, were used to compare the proportion of particles among the undiluted and diluted drug formulations., Results: Dexamethasone and betamethasone sodium phosphate were pure liquid. The proportion of larger particles was significantly greater in the methylprednisolone and the compounded betamethasone preparations compared with the commercial betamethasone. There was no statistical difference between the commercial betamethasone and triamcinolone, although betamethasone had a smaller percentage of the larger particles. Increased dilution of the compounded betamethasone with lidocaine decreased the percentage of the larger particles, whereas increased dilution of methylprednisolone 80 mg/ml with saline increased the proportion of larger particles., Conclusion: Commercial betamethasone is the recommended preparation if a nonsoluble steroid is preferred. Dexamethasone is a nonparticulate steroid, but its routine use awaits further studies on its safety and efficacy.