Patient-centered results from a multicenter study of continuous peripheral nerve blocks and postamputation phantom and residual limb pain: secondary outcomes from a randomized, clinical trial.

INTRODUCTION: We previously reported that a 6-day continuous peripheral nerve block reduces established postamputation phantom pain. To provide patients and providers with the information to best inform treatment decisions, here we reanalyze the data and present the results in a more patient-centered format. We also provide information on patient-defined clinically relevant benefits to facilitate evaluation of available studies and guide future trial design. METHODS: The original trial enrolled participants with a limb amputation and phantom pain who were randomized to receive a 6-day continuous peripheral nerve block(s) of either ropivacaine (n=71) or saline (n=73) in a double-masked fashion. Here we calculate the percentage of each treatment group that experienced a clinically relevant improvement as defined by previous studies as well as present what the participants of our study defined as small, medium, and large analgesic improvements using the 7-point ordinal Patient Global Impression of Change scale. RESULTS: Among patients who were given a 6-day ropivacaine infusion, 57% experienced at least a 2-point improvement on the 11-point numeric rating scale in their average and worst phantom pain 4 weeks postbaseline as compared with 26% (p<0.001) for average and 25% (p<0.001) for worst pain in patients given a placebo infusion. At 4 weeks, the percentage of participants rating their pain as improved was 53% for the active vs 30% for the placebo groups (95% CI 1.7 (1.1, 2.7), p=0.008). For all patients combined, the median (IQR) phantom pain Numeric Rating Scale improvements at 4 weeks considered small, medium, and large were 2 (0-2), 3 (2-5), and 5 (3-7), respectively. The median improvements in the Brief Pain Inventory interference subscale (0-70) associated with small, medium, and large analgesic changes were 8 (1-18), 22 (14-31), and 39 (26-47). CONCLUSIONS: Among patients with postamputation phantom pain, a continuous peripheral nerve block more than doubles the chance of a clinically relevant improvement in pain intensity. Amputees with phantom and/or residual limb pain rate analgesic improvements as clinically relevant similarly to other chronic pain etiologies, although their smallest relevant improvement in the Brief Pain Inventory was significantly larger than previously published values. TRIAL REGISTRATION NUMBER: NCT01824082.

Percutaneous Neuromodulation of the Brachial Plexus and Sciatic Nerve for the Treatment of Acute Pain Following Surgery: Secondary Outcomes From a Multicenter, Randomized, Controlled Pilot Study.

OBJECTIVES: We recently reported that percutaneous peripheral nerve stimulation (PNS or "neuromodulation") decreased pain and opioid consumption within the first two weeks following ambulatory surgery. However, the anatomic lead locations were combined for the analysis, and benefits for each location remain unknown. We therefore now report the effects of percutaneous PNS for brachial plexus and sciatic nerve leads separately. MATERIALS AND METHODS: Before surgery, leads were implanted percutaneously to target the brachial plexus (N = 21) for rotator cuff repair or sciatic nerve (N = 40) for foot/ankle surgery, followed by a single injection of local anesthetic. Postoperatively, subjects were randomized in a double masked fashion to 14 days of electrical stimulation (N = 30) or sham/placebo (N = 31) using an external pulse generator. The primary outcome of interest was opioid consumption and pain scores evaluated jointly. Thus, stimulation was deemed effective if superior on either outcome and at least noninferior on the other. RESULTS: For brachial plexus leads, during the first seven postoperative days pain measured with the numeric rating scale in participants given active stimulation was a median [interquartile range] of 0.8 [0.5, 1.6] versus 3.2 [2.7, 3.5] in patients given sham (p < 0.001). For this same group, opioid consumption in participants given active stimulation was 10 mg [5, 20] versus 71 mg [35, 125] in patients given sham (p = 0.043). For sciatic nerve leads, pain scores for the active treatment group were 0.7 [0, 1.4] versus 2.8 [1.6, 4.6] in patients given sham (p < 0.001). During this same period, participants given active stimulation consumed 5 mg [0, 30] of opioids versus 40 mg [20, 105] in patients given sham (p = 0.004). Treatment effects did not differ statistically between the two locations. CONCLUSIONS: Ambulatory percutaneous PNS of both the brachial plexus and sciatic nerve is an effective treatment for acute pain free of systemic side effects following painful orthopedic surgery.

Association of Peripheral Serum MicroRNAs With Persistent Phantom Limb Pain in Individuals With Amputation.

OBJECTIVE: Individuals with major limb amputation(s) frequently experience phantom limb sensations, which are described as vivid impressions of either parts or entire missing limb(s). Despite the high incidence and prevalence of phantom limb pain, the underlying pathophysiology of phantom limb pain remains poorly understood. The objective of this study was to evaluate a possible role of microRNAs in the pathophysiology of phantom limb pain. DESIGN: Adults with acquired limb amputation and varying degrees of phantom limb pain consented to provide clinical data and blood samples. One hundred forty participants with single or multiple limb amputation(s) were enrolled. The Visual analog scale and neuropathic pain symptom inventory were administered to evaluate the pain. Serum samples were analyzed for microRNA expression and bioinformatic analysis was performed. RESULTS: Sixty-seven participants did not experience phantom limb pain, whereas 73 participants experienced varying severities of phantom limb pain measured on a pain scale. Linear regression analysis suggested that the time since amputation is inversely related to severity of the pain. A significantly increased expression of 16 microRNAs was observed in participants experiencing phantom limb pain. Bioinformatic analysis shows a possible role of these microRNAs in regulating genes expressed in peripheral neuropathy. CONCLUSIONS: This study provides the first evidence of association of microRNA in phantom limb pain.

Characteristics of phantom limb pain in U.S. civilians and service members.

OBJECTIVES: The population of Americans with limb loss is on the rise, with a different profile than in previous generations (e.g., greater incidence of amputation due to diabetes). This study aimed to identify the key characteristics of phantom limb sensation (PLS) and pain (PLP) in a current sample of Americans with limb loss. METHODS: This cross-sectional study is the first large-scale (n=649) study on PLP in the current population of Americans with limb loss. A convenience sample of military and civilian persons missing one or more major limbs was surveyed regarding their health history and experience with phantom limb phenomena. RESULTS: Of the participants surveyed, 87% experienced PLS and 82% experienced PLP. PLS and PLP typically first occurred immediately after amputation (47% of cases), but for a small percentage (3-4%) onset did not occur until over a year after amputation. Recent PLP severity decreased over time (ß=0.028, 95% CI: -0.05-0.11), but most participants reported PLP even 10 years after amputation. Higher levels of recent PLP were associated with telescoping (ß=0.123, 95% CI: 0.04-0.21) and higher levels of pre-amputation pain (ß=0.104, 95% CI: 0.03-0.18). Those with congenitally missing limbs experienced lower levels of recent PLP (t (37.93)=3.93, p<0.01) but there were no consistent differences in PLP between other amputation etiologies. CONCLUSIONS: Phantom limb phenomena are common and enduring. Telescoping and pre-amputation pain are associated with higher PLP. Persons with congenitally missing limbs experience lower levels of PLP than those with amputation(s), yet PLP is common even in this subpopulation.

Immediate Effects of a Continuous Peripheral Nerve Block on Postamputation Phantom and Residual Limb Pain: Secondary Outcomes From a Multicenter Randomized Controlled Clinical Trial.

BACKGROUND: We recently reported that a 6-day continuous peripheral nerve block reduced established postamputation phantom pain 3 weeks after treatment ended. However, the immediate effects of perineural infusion (secondary outcomes) have yet to be reported. METHODS: Participants from 5 enrolling academic centers with an upper or lower limb amputation and established phantom pain received a single-injection ropivacaine peripheral nerve block(s) and perineural catheter insertion(s). They were subsequently randomized to receive a 6-day ambulatory perineural infusion of either ropivacaine 0.5% or normal saline in a double-masked fashion. Participants were contacted by telephone 1, 7, 14, 21, and 28 days after the infusion started, with pain measured using the Numeric Rating Scale. Treatment effects were assessed using the Wilcoxon rank-sum test at each time point. Adjusting for 4 time points (days 1, 7, 14, and 21), P < .0125 was deemed statistically significant. Significance at 28 days was reported using methods from the original, previously published article. RESULTS: Pretreatment average phantom and residual pain scores were balanced between the groups. The day after infusion initiation (day 1), average phantom, and residual limb pain intensity was lower in patients receiving local anesthetic (n = 71) versus placebo (n = 73): median [quartiles] of 0 [0-2.5] vs 3.3 [0-5.0], median difference (98.75% confidence interval [CI]) of -1.0 (-3.0 to 0) for phantom pain (P = .001) and 0 [0-0] vs 0 [0-4.3], and median difference 0.0 (-2.0 to 0.0) for residual limb pain (P < .001). Pain's interference with physical and emotional functioning as measured with the interference domain of the Brief Pain Inventory improved during the infusion on day 1 for patients receiving local anesthetic versus placebo: 0 [0-10] vs 10 [0-40], median difference (98.75% CI) of 0.0 (-16.0 to 0.0), P = .002. Following infusion discontinuation (day 6), a few differences were found between the active and placebo treatment groups between days 7 and 21. In general, sample medians for average phantom and residual limb pain scores gradually increased after catheter removal for both treatments, but to a greater degree in the control group until day 28, at which time the differences between the groups returned to statistical significance. CONCLUSIONS: This secondary analysis suggests that a continuous peripheral nerve block decreases phantom and residual limb pain during the infusion, although few improvements were again detected until day 28, 3 weeks following catheter removal.

Percutaneous Peripheral Nerve Stimulation (Neuromodulation) for Postoperative Pain: A Randomized, Sham-controlled Pilot Study.

BACKGROUND: Percutaneous peripheral nerve stimulation is an analgesic technique involving the percutaneous implantation of a lead followed by the delivery of electric current using an external pulse generator. Percutaneous peripheral nerve stimulation has been used extensively for chronic pain, but only uncontrolled series have been published for acute postoperative pain. The current multicenter study was undertaken to (1) determine the feasibility and optimize the protocol for a subsequent clinical trial and (2) estimate the treatment effect of percutaneous peripheral nerve stimulation on postoperative pain and opioid consumption. METHODS: Preoperatively, an electrical lead was percutaneously implanted to target the sciatic nerve for major foot/ankle surgery (e.g., hallux valgus correction), the femoral nerve for anterior cruciate ligament reconstruction, or the brachial plexus for rotator cuff repair, followed by a single injection of long-acting local anesthetic along the same nerve/plexus. Postoperatively, participants were randomized to 14 days of either electrical stimulation (n = 32) or sham stimulation (n = 34) using an external pulse generator in a double-masked fashion. The dual primary treatment effect outcome measures were (1) cumulative opioid consumption (in oral morphine equivalents) and (2) mean values of the "average" daily pain scores measured on the 0 to 10 Numeric Rating Scale within the first 7 postoperative days. RESULTS: During the first 7 postoperative days, opioid consumption in participants given active stimulation was a median (interquartile range) of 5 mg (0 to 30) versus 48 mg (25 to 90) in patients given sham treatment (ratio of geometric means, 0.20 [97.5% CI, 0.07 to 0.57]; P < 0.001). During this same period, the average pain intensity in patients given active stimulation was a mean ± SD of 1.1 ± 1.1 versus 3.1 ± 1.7 in those given sham (difference, -1.8 [97.5% CI, -2.6 to -0.9]; P < 0.001). CONCLUSIONS: Percutaneous peripheral nerve stimulation reduced pain scores and opioid requirements free of systemic side effects during at least the initial week after ambulatory orthopedic surgery.

Ambulatory continuous peripheral nerve blocks to treat postamputation phantom limb pain: a multicenter, randomized, quadruple-masked, placebo-controlled clinical trial.

Phantom limb pain is thought to be sustained by reentrant neural pathways, which provoke dysfunctional reorganization in the somatosensory cortex. We hypothesized that disrupting reentrant pathways with a 6-day-long continuous peripheral nerve block reduces phantom pain 4 weeks after treatment. We enrolled patients who had an upper- or lower-limb amputation and established phantom pain. Each was randomized to receive a 6-day perineural infusion of either ropivacaine or normal saline. The primary outcome was the average phantom pain severity as measured with a Numeric Rating Scale (0-10) at 4 weeks, after which an optional crossover treatment was offered within the following 0 to 12 weeks. Pretreatment pain scores were similar in both groups, with a median (interquartile range) of 5.0 (4.0, 7.0) for each. After 4 weeks, average phantom limb pain intensity was a mean (SD) of 3.0 (2.9) in patients given local anesthetic vs 4.5 (2.6) in those given placebo (difference [95% confidence interval] 1.3 [0.4, 2.2], P = 0.003). Patients given local anesthetic had improved global impression of change and less pain-induced physical and emotional dysfunction, but did not differ on depression scores. For subjects who received only the first infusion (no self-selected crossover), the median decrease in phantom limb pain at 6 months for treated subjects was 3.0 (0, 5.0) vs 1.5 (0, 5.0) for the placebo group; there seemed to be little residual benefit at 12 months. We conclude that a 6-day continuous peripheral nerve block reduces phantom limb pain as well as physical and emotional dysfunction for at least 1 month.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation: A Pragmatic Effectiveness Trial of a Nonpharmacologic Alternative for the Treatment of Postoperative Pain.

BACKGROUND: Percutaneous peripheral nerve stimulation (PNS) is an analgesic modality involving the insertion of a lead through an introducer needle followed by the delivery of electric current after needle withdrawal. This modality has been used extensively to treat chronic pain, but only small series have been published involving postoperative pain. The ultimate objective of this study is to determine the postoperative effects of percutaneous PNS following moderately to severely painful ambulatory surgery within a real-world clinical practice setting. The primary hypothesis is that surgical pain and opioid consumption during the initial 7 days after surgery will be reduced by percutaneous PNS compared with usual and customary analgesia (dual primary outcome measures). DESIGN: A multicenter pragmatic effectiveness trial. We are randomizing participants having painful orthopedic surgical procedures of the upper and lower extremity to receive 14 days of either 1) electrical stimulation or 2) sham in a double-masked fashion. End points are being assessed at various time points over 12 postoperative months. SUMMARY: The postoperative experience will be much improved if percutaneous PNS provides potent analgesia while concurrently decreasing opioid requirements following painful surgery. Because this modality can be administered for up to 60 days at home, it may provide postoperative analgesia that outlasts surgical pain yet has relatively few risks and, unlike opioids, has no systemic side effects or potential for abuse, addiction, and overdose. Percutaneous PNS has the potential to revolutionize postoperative analgesia as it has been practiced for the past century. This study will inform key stakeholders regarding an evidence-based nonpharmacologic approach to the management of postoperative pain.

Percutaneous Peripheral Nerve Stimulation to Control Postoperative Pain, Decrease Opioid Use, and Accelerate Functional Recovery Following Orthopedic Trauma.

Orthopedic trauma is a significant military problem, causing several of the most disabling conditions with high rates of separation from duty and erosion of military readiness. The objective of this report is to summarize the findings of case series of a non-opioid therapy-percutaneous peripheral nerve stimulation (PNS) - and describe its potential for postoperative analgesia, early opioid cessation, and improved function following orthopedic trauma. Percutaneous PNS has been evaluated for the treatment of multiple types of pain, including two case series on postoperative pain following total knee replacement (n = 10 and 8, respectively) and a case series on postamputation pain (n = 9). The orthopedic trauma induced during TKR is highly representative of multiple types of orthopedic trauma sustained by Service members and frequently produces intense, prolonged postoperative pain and extended opioid use following surgery. Collectively, the results of these three clinical studies demonstrated that percutaneous PNS can provide substantial pain relief, reduce opioid use, and improve function. These outcomes suggest that there is substantial potential for the use of percutaneous PNS following orthopedic trauma.

Percutaneous Peripheral Nerve Stimulation for Pain Reduction and Improvements in Functional Outcomes in Chronic Low Back Pain.

Chronic low back pain represents one of the most common sources of disability and a significant healthcare burden for the U.S. military. Present treatments for chronic back pain are often ineffective, poorly tolerated, invasive, destructive, and/or associated with complications and lead to the progression to invasive surgical procedures. There have been multiple calls for the development of a minimally invasive system that is effective without the risks or complications of existing surgical therapies, which could prevent the need for surgery and the recurrence of pain. The goal of this study was to evaluate a novel, minimally invasive approach using a percutaneous peripheral nerve stimulation (PNS) system designed to provide pain relief without surgery, to reduce complications, and provide a less-invasive treatment option. In nine subjects, percutaneous PNS improved participants' function, as evidenced by clinically and statistically significant reductions in pain, disability, and pain interference. Subjects also experienced reductions in opioid and non-opioid analgesic medication usage and reported improvements in quality of life with treatment. There were no serious or unanticipated adverse events. These results demonstrate the potential of percutaneous PNS as a non-surgical therapy to treat chronic back pain without opioids.

Challenges with Implementing the Centers for Disease Control and Prevention Opioid Guideline: A Consensus Panel Report.

BACKGROUND: A national crisis of opioid-related morbidity, mortality, and misuse has led to initiatives to address the appropriate role of opioids to treat pain. Deployment of a guideline from the Centers for Disease Control and Prevention to reduce the risks of opioid therapy has raised substantial clinical and public policy challenges. The agency anticipated implementation challenges and committed to reevaluating the guideline for intended and unintended effects on clinician and patient outcomes. OBSERVATIONS: A multidisciplinary expert panel met to review the influence of the core recommendations of the guideline on pain management practices, principally regarding the estimated 5 to 8 million Americans with chronic pain currently on opioids. The panel identified implementation challenges, including application of dosage ceilings and prescription duration guidance, failure to appreciate the importance of patient involvement in decisions to taper or discontinue opioids, barriers to diagnosis and treatment of opioid use disorder, and impeded access to recommended comprehensive, multimodal pain care. Furthermore, policy-making and regulatory bodies may misapply guideline recommendations without flexibility and, sometimes, without full awareness of what the guideline contains. CONCLUSIONS AND RELEVANCE: The panel largely supported the guideline, endorsing its focal points of safety and comprehensive assessment and monitoring. To mitigate clinical and policy challenges identified with implementing the guideline, the panel discussed areas where viewpoints diverged and arrived at consensus proposals. The target audience includes the leaders and institutions that create policy and influence guideline implementation to include regulatory agencies, legislators, public and private payers, and health care systems.

Evaluation of the Validity and Response Burden of Patient Self-Report Measures of the Pain Assessment Screening Tool and Outcomes Registry (PASTOR).

BACKGROUND: In 2009, the Army Pain Management Task Force was chartered. On the basis of their findings, the Department of Defense recommended a comprehensive pain management strategy that included development of a standardized pain assessment system that would collect patient-reported outcomes data to inform the patient-provider clinical encounter. The result was the Pain Assessment Screening Tool and Outcomes Registry (PASTOR). The purpose of this study was to assess the validity and response burden of the patient-reported outcome measures in PASTOR. METHODS: Data for analyses were collected from 681 individuals who completed PASTOR at baseline and follow-up as part of their routine clinical care. The survey tool included self-report measures of pain severity and pain interference (measured using the National Institutes of Health Patient-Reported Outcome Measurement Information System [PROMIS] and the Defense and Veterans Pain Rating scale). PROMIS measures of pain correlates also were administered. Validation analyses included estimation of score associations among measures, comparison of scores of known groups, responsiveness, ceiling and floor effects, and response burden. RESULTS: Results of psychometric testing provided substantial evidence for the validity of PASTOR self-report measures in this population. Expected associations among scores largely supported the concurrent validity of the measures. Scores effectively distinguished among respondents on the basis of their self-reported impressions of general health. PROMIS measures were administered using computer adaptive testing and each, on average, required less than 1 minute to administer. Statistical and graphical analyses demonstrated the responsiveness of PASTOR measures over time.

Collaborative Approach to the Creation of an Arteriovenous Fistula on a US Navy Hospital Ship.

Early creation of arteriovenous fistulas (AVFs) decreases morbidity and mortality in patients with end-stage renal disease and is the standard of care in the United States. However, this procedure is frequently not accessible in low- and middle-income countries (LMICs). We present the first reported case of successful AVF creation as part of a humanitarian assistance mission. The patient was a 51-year-old male with diabetes, hypertension, and end-stage renal disease on hemodialysis via a temporary dialysis catheter. Preoperative assessment and patient selection were coordinated with the host nation (HN) nephrologist and dialysis team. The visiting surgical team provided education on AVF anatomy, complications, and cannulation techniques to the HN dialysis team. A left brachiocephalic AVF was created under regional anesthesia performed by the visiting surgeon and anesthesiologists. There were no postoperative complications, and the AVF was matured and accessed successfully by the HN dialysis team 7 weeks after creation. Performing AVFs as part of humanitarian assistance missions has the potential to significantly reduce morbidity and mortality in LMICs.

Stellate Ganglion Block for the Treatment of Posttraumatic Stress Disorder: A Randomized, Double-Blind, Controlled Trial.

OBJECTIVE: In this study, we aimed to determine if stellate ganglion block (SGB) could reduce symptoms of posttraumatic stress disorder (PTSD) in comparison with sham therapy in military service members. METHODS: In a randomized trial in which both participants and assessors were blind, participants with PTSD received either an SGB or a sham procedure. Posttraumatic stress disorder symptoms were measured using the CAPS (Clinician-Administered PTSD Scale) and self-report measures of PTSD, depression, anxiety, and pain. Subjects underwent assessment before the procedure and at 1 week, 1 month, and 3 months after the procedure. Patients receiving sham injections were allowed to cross over to the treatment group, and participants who maintained criteria for PTSD were allowed to receive a second SGB treatment. RESULTS: Posttraumatic stress disorder, anxiety, and depression scores all showed improvement across time, but there was no statistically or clinically relevant difference in outcomes between the active and control groups. Individuals who crossed over from sham treatment to SGB similarly showed no greater improvement with the SGB treatment. Improvement in CAPS was greater with a second SGB treatment than after the first treatment. CONCLUSIONS: Although previous case series have suggested that SGB offers an effective intervention for PTSD, this study did not demonstrate any appreciable difference between SGB and sham treatment on psychological or pain outcomes. Future studies should examine if differences in treatment methods or patient population could allow individuals with PTSD to benefit from SGB, but current evidence does not support widespread or indiscriminant clinical use of the procedure for PTSD.

Intravenous Cosyntropin Versus Epidural Blood Patch for Treatment of Postdural Puncture Headache.

OBJECTIVE: This study evaluated the efficacy of IV cosyntropin as an alternative to epidural blood patch (EBP) for refractory or severe post-dural puncture headache (PDPH). METHODS: Twenty-eight patients were randomized to receive EBP or intravenous cosyntropin after diagnosis with post-dural puncture headache. Efficacy was evaluated immediately after treatment and at 1 day, 3 days, and 7 days following treatment using self-reported verbal reported scores for pain and function related to their headache on a 10-point scale using two-way repeated measures analysis of variance (ANOVA) with multiple comparisons. RESULTS: Baseline information for the control and study cohorts showed no difference based on intent to treat analysis. EBP showed significant improvement over cosyntropin at day 1 (P < 0.001) for VRS pain and function scores; however, cosyntropin demonstrated similar efficacy to EBP immediately after treatment and days 3 and 7 post treatment (respectively, P = 0.459, P = 0.391 and 0.925 for pain and P = 0.189 and 0.478 for function). Treatment effects remained at day 1 after multivariate analysis (P < 0.001 and P = 0.002 for pain and function, respectively). CONCLUSIONS: It is reasonable to consider IV cosyntropin as the treatment of choice for patients in whom EBP is contraindicated or in austere environments where there is limited or no access to anesthesia trained providers. Future research should compare efficacy and cost of prophylaxis to treatment of PDPH with intravenous cosyntropin and evaluate the most effective dosing regimen, including duration, number, and strength of doses.

Randomized, double-blind, comparative-effectiveness study comparing pulsed radiofrequency to steroid injections for occipital neuralgia or migraine with occipital nerve tenderness.

Occipital neuralgia (ON) is characterized by lancinating pain and tenderness overlying the occipital nerves. Both steroid injections and pulsed radiofrequency (PRF) are used to treat ON, but few clinical trials have evaluated efficacy, and no study has compared treatments. We performed a multicenter, randomized, double-blind, comparative-effectiveness study in 81 participants with ON or migraine with occipital nerve tenderness whose aim was to determine which treatment is superior. Forty-two participants were randomized to receive local anesthetic and saline, and three 120 second cycles of PRF per targeted nerve, and 39 were randomized to receive local anesthetic mixed with deposteroid and 3 rounds of sham PRF. Patients, treating physicians, and evaluators were blinded to interventions. The PRF group experienced a greater reduction in the primary outcome measure, average occipital pain at 6 weeks (mean change from baseline -2.743 ± 2.487 vs -1.377 ± 1.970; P < 0.001), than the steroid group, which persisted through the 6-month follow-up. Comparable benefits favoring PRF were obtained for worst occipital pain through 3 months (mean change from baseline -1.925 ± 3.204 vs -0.541 ± 2.644; P = 0.043), and average overall headache pain through 6 weeks (mean change from baseline -2.738 ± 2.753 vs -1.120 ± 2.1; P = 0.037). Adverse events were similar between groups, and few significant differences were noted for nonpain outcomes. We conclude that although PRF can provide greater pain relief for ON and migraine with occipital nerve tenderness than steroid injections, the superior analgesia may not be accompanied by comparable improvement on other outcome measures.

Symptoms of PTSD Associated With Painful and Nonpainful Vicarious Reactivity Following Amputation.

Although the experience of vicarious sensations when observing another in pain have been described postamputation, the underlying mechanisms are unknown. We investigated whether vicarious sensations are related to posttraumatic stress disorder (PTSD) symptoms and chronic pain. In Study 1, 236 amputees completed questionnaires about phantom limb phenomena and vicarious sensations to both innocuous and painful sensory experiences of others. There was a 10.2% incidence of vicarious sensations, which was significantly more prevalent in amputees reporting PTSD-like experiences, particularly increased arousal and reexperiencing the event that led to amputation (φ = .16). In Study 2, 63 amputees completed the Empathy for Pain Scale and PTSD Checklist-Civilian Version. Cluster analyses revealed 3 groups: 1 group did not experience vicarious pain or PTSD symptoms, and 2 groups were vicarious pain responders, but only 1 had increased PTSD symptoms. Only the latter group showed increased chronic pain severity compared with the nonresponder group (p = .025) with a moderate effect size (r = .35). The findings from both studies implicated an overlap, but also divergence, between PTSD symptoms and vicarious pain reactivity postamputation. Maladaptive mechanisms implicated in severe chronic pain and physical reactivity posttrauma may increase the incidence of vicarious reactivity to the pain of others.

Epidural steroid injections compared with gabapentin for lumbosacral radicular pain: multicenter randomized double blind comparative efficacy study.

OBJECTIVE: To evaluate whether an epidural steroid injection or gabapentin is a better treatment for lumbosacral radiculopathy. DESIGN: A multicenter randomized study conducted between 2011 and 2014. Computer generated randomization was stratified by site. Patients and evaluating physicians were blinded to treatment outcomes. SETTINGS: Eight military, Veterans Administration, and civilian hospitals. PARTICIPANTS: 145 people with lumbosacral radicular pain secondary to herniated disc or spinal stenosis for less than four years in duration and in whom leg pain is as severe or more severe than back pain. INTERVENTIONS: Participants received either epidural steroid injection plus placebo pills or sham injection plus gabapentin. MAIN OUTCOME MEASURES: Average leg pain one and three months after the injection on a 0-10 numerical rating scale. A positive outcome was defined as a ≥ 2 point decrease in leg pain coupled with a positive global perceived effect. All patients had one month follow-up visits; patients whose condition improved remained blinded for their three month visit. RESULTS: There were no significant differences for the primary outcome measure at one month (mean pain score 3.3 (SD 2.6) and mean change from baseline -2.2 (SD 2.4) in epidural steroid injection group versus 3.7 (SD 2.6) and -1.7 (SD 2.6) in gabapentin group; adjusted difference 0.4, 95% confidence interval -0.3 to 1.2; P=0.25) and three months (mean pain score 3.4 (SD 2.7) and mean change from baseline -2.0 (SD 2.6) versus 3.7 (SD 2.8) and -1.6 (SD 2.7), respectively; adjusted difference 0.3, -0.5 to 1.2; P=0.43). Among secondary outcomes, one month after treatment those who received epidural steroid injection had greater reductions in worst leg pain (-3.0, SD 2.8) than those treated with gabapentin (-2.0, SD 2.9; P=0.04) and were more likely to experience a positive successful outcome (66% v 46%; number needed to treat=5.0, 95% confidence interval 2.8 to 27.0; P=0.02). At three months, there were no significant differences between treatments. CONCLUSIONS: Although epidural steroid injection might provide greater benefit than gabapentin for some outcome measures, the differences are modest and are transient for most people.Trial registration ClinicalTrials.gov Identifier: NCT01495923.