Peripheral Nerve Stimulation of the Shoulder: A Technical Primer.

Scapulalgia or shoulder pain accounts for 16% of all musculoskeletal complaints in the healthy adult population and becomes more common as we age. When this pain exceeds 3 months in duration, it is deemed to be chronic, and typically treated in an escalating manner. Spanning a continuum of conservative and non-conservative measures, chronic shoulder pain treatments range from rest and physical therapy to surgery. Since each patient presents with a unique spectrum of symptoms a customized treatment plan is often required. Over the lifetime of many of these patients, a variety of treatment options are required. One of these treatment options, peripheral nerve stimulation (PNS), is a minimally invasive procedure in which an electrical impulse is delivered through a percutaneously implanted, small caliber electrode to a peripheral nerve proximal to the lesion which interferes with the pain signals. Over the past several years, significant growth of PNS in the treatment of chronic neuropathic pain has been observed. However, the procedural techniques have not been well described. The foundation of long-term, minimally invasive percutaneous PNS in patients with chronic shoulder pain, and procedural techniques for stimulating the suprascapular and axillary nerves using fluoroscopy or ultrasonography will be described in this report.

Results From a Prospective, Clinical Study (US-nPower) Evaluating a Miniature Spinal Cord Stimulator for the Management of Chronic, Intractable Pain.

BACKGROUND: Chronic, intractable, neuropathic pain is readily treatable with spinal cord stimulation (SCS). Technological advancements, including device miniaturization, are advancing the field of neuromodulation. OBJECTIVES: We report here the results of an SCS clinical trial to treat chronic, low back and leg pain, with a micro-implantable pulse generator (micro-IPG). STUDY DESIGN: This was a single-arm, prospective, multicenter, postmarket, observational study. SETTING: Patients were recruited from 15 US-based comprehensive pain centers. METHODS: This open-label clinical trial was designed to evaluate the performance of the Nalu™ Neurostimulation System (Nalu Medical, Inc., Carlsbad, CA) in the treatment of low back and leg pain. Patients, who provided informed consent and were successfully screened for study entry, were implanted with temporary trial leads. Patients went on to receive a permanent implant of the leads and micro-IPG if they demonstrated a >= 50% reduction in pain during the temporary trial period. Patient-reported outcomes (PROs), such as pain scores, functional disability, mood, patient impression of change, comfort, therapy use profile, and device ease of use, were captured. RESULTS: At baseline, the average pain Visual Analog Scale (VAS) score was 72.1 ± 17.9 in the leg and 78.0 ± 15.4 in the low back. At 90 days following permanent implant (end of study), pain scores improved by 76% (VAS 18.5 ± 18.8) in the leg and 75% (VAS 19.7 ± 20.8) in the low back. Eighty-six percent  of both leg pain and low back pain patients demonstrated a >= 50% reduction in pain at 90 days following implant. The comfort of the external wearable (Therapy Disc and Adhesive Clip) was rated 1.16 ± 1.53, on average, at 90 days on an 11-point rating scale (0 = very comfortable, 10 = very uncomfortable). All PROs demonstrated statistically significant symptomatic improvement at 90 days following implant of the micro-IPG. LIMITATIONS:   Limitations of this study include the lack of long-term results (beyond 90 days) and a relatively small sample size of 35 patients who were part of the analysis; additionally, there was no control arm or randomization as this was a single-arm study, without a comparator, designed to document the efficacy and safety of the device. Therefore, no direct comparisons to other SCS systems were possible. CONCLUSIONS: This clinical study demonstrated profound leg and low back pain relief in terms of overall pain reduction, as well as the proportion of therapy responders. The study patients reported the wearable aspects of the system to be very comfortable.

Physical Therapy Considerations and Recommendations for Patients Following Spinal Cord Stimulator Implant Surgery.

OBJECTIVES: Spinal cord stimulation (SCS) is an established therapy option in interventional pain medicine. Recent advances in technology have allowed for greater compliance with treatment and improved efficacy in pain control. This article was proposed to fill the gap in the literature addressing this specific patient population and to facilitate further research. Even though there is a lack of consensus among societies and experts on exact parameters of physical therapy (PT) considerations and postoperative limitations in patients with SCS, we propose rehabilitative care for this population should be standardized. As the number of patients with SCS implants grow, it is vital to understand how to appropriately approach patients with implantable devices when additional treatments such as PT are prescribed. MATERIALS AND METHODS: A literature search was performed on the use of PT following SCS implantation. Presently, there is no literature to date which addresses the use of PT in this patient population. The lack of data is the largest hurdle in the creation of formal SCS therapy guidelines. The authors therefore proposed recommendations for rehabilitation based upon a detailed understanding of SCS hardware alongside well-studied physiotherapy concepts. RESULTS: Considerations when initiating PT in the SCS patient population should include: 1) biomechanics and quality of SCS output; 2) therapeutic exercise and spinal manipulation in association with risk for lead migration and fracture; 3) the application of therapeutic modalities and risk for injury to the patient and/or damage to the SCS componentry; and 4) integration of a biopsychosocial, person-centered approach. CONCLUSIONS: PT treatment protocol in patients with a recently implanted SCS device should be person-centered addressing individual needs, values, and goals. Further research is needed to fully appreciate the impact of an interprofessional approach to management of SCS patients, particularly following stimulator implantation.

The interdisciplinary management of coccydynia: A narrative review.

Pain that develops in the coccyx or surrounding tissues is known as coccydynia, which occurs as a result of many etiologies both traumatic and nontraumatic. Although coccydynia most commonly affects middle-aged women, it may be found in both sexes and in all age groups. The aim of this article is to provide an overview of the presentation, diagnostic imaging, and pathophysiology of coccydynia, and to comprehensively review the current treatment options. A review of publications from 1990 to 2020 using search words related to the treatment of coccydynia in PubMed and Google Scholar was completed. Level II evidence was found supporting stretching, manipulation, and extracorporeal shock wave therapy. There are no data from high-quality studies to support injection-based therapy including corticosteroids, prolotherapy, nerve blocks, and radiofrequency ablation, although there are small retrospective and prospective observational studies suggesting benefit. Level III evidence was found supporting coccygectomy for chronic/refractory coccydynia. There are no data from randomized controlled trials to support the use of neuromodulation (sacral burst and dorsal root ganglion stimulation), although there are case reports suggesting benefit. High-level, comparative studies are lacking to guide the treatment of coccydynia and should be a focus for future research studies.

Treatment of chronic axial back pain with 60-day percutaneous medial branch PNS: Primary end point results from a prospective, multicenter study.

BACKGROUND: The objective of this prospective, multicenter study is to characterize responses to percutaneous medial branch peripheral nerve stimulation (PNS) to determine if results from earlier, smaller single-center studies and reports were generalizable when performed at a larger number and wider variety of centers in patients recalcitrant to nonsurgical treatments. MATERIALS & METHODS: Participants with chronic axial low back pain (LBP) were implanted with percutaneous PNS leads targeting the lumbar medial branch nerves for up to 60 days, after which the leads were removed. Participants were followed long-term for 12 months after the 2-month PNS treatment. Data collection is complete for visits through end of treatment with PNS (primary end point) and 6 months after lead removal (8 months after start of treatment), with some participant follow-up visits thereafter in progress. RESULTS: Clinically and statistically significant reductions in pain intensity, disability, and pain interference were reported by a majority of participants. Seventy-three percent of participants were successes for the primary end point, reporting clinically significant (≥30%) reductions in back pain intensity after the 2-month percutaneous PNS treatment (n = 54/74). Whereas prospective follow-up is ongoing, among those who had already completed the long-term follow-up visits (n = 51), reductions in pain intensity, disability, and pain interference were sustained in a majority of participants through 14 months after the start of treatment. CONCLUSION: Given the minimally invasive, nondestructive nature of percutaneous PNS and the significant benefits experienced by participants who were recalcitrant to nonsurgical treatments, percutaneous PNS may provide a promising first-line neurostimulation treatment option for patients with chronic axial back pain.

Percutaneous Peripheral Nerve Stimulation of the Medial Branch Nerves for the Treatment of Chronic Axial Back Pain in Patients After Radiofrequency Ablation.

OBJECTIVE: Lumbar radiofrequency ablation is a commonly used intervention for chronic back pain. However, the pain typically returns, and though retreatment may be successful, the procedure involves destruction of the medial branch nerves, which denervates the multifidus. Repeated procedures typically have diminishing returns, which can lead to opioid use, surgery, or implantation of permanent neuromodulation systems. The objective of this report is to demonstrate the potential use of percutaneous peripheral nerve stimulation (PNS) as a minimally invasive, nondestructive, motor-sparing alternative to repeat radiofrequency ablation and more invasive surgical procedures. DESIGN: Prospective, multicenter trial. METHODS: Individuals with a return of chronic axial pain after radiofrequency ablation underwent implantation of percutaneous PNS leads targeting the medial branch nerves. Stimulation was delivered for up to 60 days, after which the leads were removed. Participants were followed up to 5 months after the start of PNS. Outcomes included pain intensity, disability, and pain interference. RESULTS: Highly clinically significant (≥50%) reductions in average pain intensity were reported by a majority of participants (67%, n = 10/15) after 2 months with PNS, and a majority experienced clinically significant improvements in functional outcomes, as measured by disability (87%, n = 13/15) and pain interference (80%, n = 12/15). Five months after PNS, 93% (n = 14/15) reported clinically meaningful improvement in one or more outcome measures, and a majority experienced clinically meaningful improvements in all three outcomes (i.e., pain intensity, disability, and pain interference). CONCLUSIONS: Percutaneous PNS has the potential to shift the pain management paradigm by providing an effective, nondestructive, motor-sparing neuromodulation treatment.

Postoperative Infections Associated With Prolonged Spinal Cord Stimulation Trial Duration (PROMISE RCT).

INTRODUCTION: In the PROMISE study, a multinational randomized controlled trial (RCT) of the effectiveness of spinal cord stimulation (SCS) with multicolumn surgical leads as a treatment of low back pain, clinicians followed their usual practice. An early, unplanned safety analysis revealed that the infection rate in Belgium (5/23), where trial duration was a median 21.5 days, was significantly higher than the 1/64 rate observed in the other study countries (median 5.8 days, p < 0.01). This report reviews infections observed in the PROMISE study after study completion. MATERIALS AND METHODS: For all infections related to SCS, we used descriptive statistics and tests of independent variables to analyze potentially contributing factors (age, sex, coexisting medical conditions, tobacco use, lead type, and trial duration) between subjects with infections versus those without. Cumulative incidence curves were created using the Kaplan-Meier method and compared between the two strata using a log-rank test. RESULTS: Among nine (5.2%) infections in 174 subjects trialed, the only significant contributing factor to infection was trial duration: median 21 days (range 3-56) for those with infection vs. six days (1-41) for those without (p = 0.001; Wilcoxon rank-sum test). The cumulative incidence of infection for subjects trialed >10 days was 24.1% vs. 1.4% for subjects trialed ≤10 days (p < 0.001). After the protocol was amended to limit trial duration to 10 days, 14 infection-free trials were performed in Belgium. CONCLUSIONS: Although not part of the preplanned analysis, our observation supports the hypothesis of a cause-effect relationship between trial duration and the risk of infection and the conclusion that prolonged SCS trials should be avoided.

Regenerative Medicine for Axial and Radicular Spine-Related Pain: A Narrative Review.

INTRODUCTION: Regenerative injection-based therapy has established itself as a therapeutic option for the management of a variety of painful musculoskeletal conditions. The aim of this work was to review the current literature regarding regenerative injection therapy for axial/radicular spine pain. METHODS: A comprehensive literature review was conducted on the use of regenerative medicine for axial/radicular spine pain. Eligible articles analyzed the therapeutic injection effects of platelet-rich plasma (PRP), prolotherapy, or mesenchymal signaling cells (MSCs) via intradiscal, facet joint, epidural, or sacroiliac joint delivery. RESULTS: Regarding intradiscal PRP, there are level I/IV studies supporting its use. Regarding intradiscal prolotherapy, there are level III to IV studies supporting its use. Regarding intradiscal MSCs, there are level I/IV studies supporting its use with the exception of one level IV study that found no significant improvement at 12 months. Regarding facet joint injections with PRP, there are level I/IV studies supporting its use. Regarding facet joint injections with prolotherapy, there are level IV studies supporting its use, though the one level I study did not demonstrate any statistical significance supporting its use. Regarding epidural injections with PRP, there are level I/IV studies supporting its use. Regarding epidural injections with prolotherapy, there are level IV studies supporting its use, though the one level I study did not demonstrate statistical significance beyond 48 hours. Regarding sacroiliac joint injections with PRP, there are level I/IV studies supporting its use. Regarding sacroiliac joint injections with prolotherapy, there are level I/III studies supporting its use. CONCLUSIONS: Currently, there are level I studies to support the use of PRP and MSC injections for discogenic pain; facet joint injections with PRP; epidural injections of autologous conditioned serum and epidural prolotherapy; and PRP and prolotherapy for sacroiliac joint pain. One level I study showed that facet joint prolotherapy has no significant benefit. Notably, no intervention has multiple published level I studies.

Demonstration of Lesions Produced by Cooled Radiofrequency Neurotomy for Chronic Osteoarthritic Knee Pain: A Case Presentation.

This case presentation demonstrates radiographic evidence of lesions created following cooled radiofrequency (cRF) neurotomy of the knee. A 67-year-old man presented with chronic left knee osteoarthritis, pain, and disability. After a failed trial of conservative treatments, the patient underwent diagnostic genicular nerve blocks and subsequent cRF neurotomy of the left knee. Shortly after cRF, magnetic resonance imaging (MRI) of the left knee was performed. On MRI, lesions created by cRF ablation were identified. The images presented in this case offer a visual explanation for the success of cRF in the treatment of knee osteoarthritis. LEVEL OF EVIDENCE: V.

A Prospective, Randomized, Multicenter, Open-label Clinical Trial Comparing Intradiscal Biacuplasty to Conventional Medical Management for Discogenic Lumbar Back Pain.

STUDY DESIGN: This study was a prospective, randomized, crossover, multicenter trial for the evaluation of comparative effectiveness of intradiscal biacuplasty (IDB) versus conventional medical management (CMM) in the treatment of lumbar discogenic pain. OBJECTIVE: The objective was to demonstrate the superiority of IDB over CMM in the treatment of discogenic pain with respect to the primary outcome measure. SUMMARY OF BACKGROUND DATA: Current therapeutic options for the treatment of chronic low back pain of discogenic origin are limited. CMM is often unsatisfactory with regard to the treatment of discogenic pain. IDB offers a minimally invasive treatment that has been demonstrated to be superior to placebo in the past. METHODS: A total of 63 subjects with lumbar discogenic pain diagnosed via provocation discography were randomized to IDB + CMM (n = 29) or CMM-alone (n = 34). At 6 months, patients in the CMM-alone group were eligible for crossover if desired. The primary outcome measure was the change in visual analog scale (VAS) from baseline to 6 months. Secondary outcome measures included treatment "responders," defined as the proportion of subjects with a 2-point or 30% decrease in VAS scores. Other secondary measures included changes from baseline to 6 months in (1) short form (SF) 36-physical functioning, (2) Oswestry Disability Index, (3) Beck Depression Inventory, (4) Patient Global Impression of Change, (5) EQ-5D VAS, and (6) back pain-related medication usage. RESULTS: In the IDB cohort, the mean VAS score reduction exceeded that in the CMM cohort (-2.4 vs. -0.56; P = 0.02), and the proportion of treatment responders was substantially greater (50% vs. 18%). Differences in secondary measures favored IDB. No differences in opioid utilization were noted between groups. CONCLUSION: Superior performance of IDB with respect to all study outcomes suggests that it is a more effective treatment for discogenic pain than CMM-alone. LEVEL OF EVIDENCE: 2.

Rehabilitation perspectives of neuromodulation.

Chronic pain is one of the most prevalent and costly health care problems in the United States today. Two conditions, failed back surgery syndrome (FBSS) and complex regional pain syndrome (CRPS), in particular have been difficult to manage, resulting in increased disability and poorer quality of life measures for patients as well as increased treatments cost for payers. Given the cost of chronic pain management and overall subjectivity of analog pain scores, many payers are emphasizing the importance of functional outcomes as a means of assessing efficacy of treatment. Neuromodulation devices such as spinal cord stimulators are shown to be cost effective and able to improve functional outcomes and quality of life. Specific rehabilitation therapies also demonstrate improved functional outcomes. This article aims to discuss the role of rehabilitation in the patient with a neuromodulatory device. From the available data and our clinical experience, we recommend incorporating rehabilitation after placement of a neuromodulation device in order to optimize functional outcomes.

Lumbar zygapophyseal pain during extension-based stabilization protocol following lumbar transdiscal biacuplasty.

INTRODUCTION: Transdiscal biacuplasty (TDB) is a minimally invasive procedure for the treatment of lumbar discogenic pain. Theoretically, TDB ablates the aberrant ingrowth of nerve fibers beyond the outer third of the annulus fibrosis of the lumbar intervertebral disk and treats annular tears via collagen reformation. Typically, recovery involves a robust rehabilitation protocol that emphasizes lumbar stabilization exercises, focusing on extension maneuvers while also strengthening the multifidi and transverse abdominus. New-onset postprocedural pain during recovery may occur; evaluation of nondiscogenic causes should be considered. We report 3 of 12 patients who developed zygapophyseal-mediated pain during the recovery period. CASES: Three of 12 patients who underwent TDB over a 1-year period, developed zygapophyseal-mediated back pain at the level of the original discogenic pathology. All three underwent unilateral intra-articular zygapophyseal injections with resolution of their new-onset symptoms. DISCUSSION: Novel postprocedural low back pain should provoke re-evaluation of potential etiologies such as persistent discogenic pathology, zygapophyseal or sacroiliac joint involvement, and other mechanical sources of pain. We postulate that extension maneuvers during rehabilitation, combined with lumbar bracing in extension, inadvertently triggered and potentially exacerbated pre-existing zygapophyseal irritation. The clinical implication of this scenario is novel distracting pain, caused by an alternative etiology to the original discogenic pain, and may present a confounder to the assessment of the efficacy of TDB.

Predictors of pain relief following spinal cord stimulation in chronic back and leg pain and failed back surgery syndrome: a systematic review and meta-regression analysis.

We sought to assess the extent to which pain relief in chronic back and leg pain (CBLP) following spinal cord stimulation (SCS) is influenced by patient-related factors, including pain location, and technology factors. A number of electronic databases were searched with citation searching of included papers and recent systematic reviews. All study designs were included. The primary outcome was pain relief following SCS, we also sought pain score (pre- and post-SCS). Multiple predictive factors were examined: location of pain, history of back surgery, initial level of pain, litigation/worker's compensation, age, gender, duration of pain, duration of follow-up, publication year, continent of data collection, study design, quality score, method of SCS lead implant, and type of SCS lead. Between-study association in predictive factors and pain relief were assessed by meta-regression. Seventy-four studies (N = 3,025 patients with CBLP) met the inclusion criteria; 63 reported data to allow inclusion in a quantitative analysis. Evidence of substantial statistical heterogeneity (P < 0.0001) in level of pain relief following SCS was noted. The mean level of pain relief across studies was 58% (95% CI: 53% to 64%, random effects) at an average follow-up of 24 months. Multivariable meta-regression analysis showed no predictive patient or technology factors. SCS was effective in reducing pain irrespective of the location of CBLP. This review supports SCS as an effective pain relieving treatment for CBLP with predominant leg pain with or without a prior history of back surgery. Randomized controlled trials need to confirm the effectiveness and cost-effectiveness of SCS in the CLBP population with predominant low back pain.

Spinal cord stimulation for predominant low back pain in failed back surgery syndrome: study protocol for an international multicenter randomized controlled trial (PROMISE study).

BACKGROUND: Although results of case series support the use of spinal cord stimulation in failed back surgery syndrome patients with predominant low back pain, no confirmatory randomized controlled trial has been undertaken in this patient group to date. PROMISE is a multicenter, prospective, randomized, open-label, parallel-group study designed to compare the clinical effectiveness of spinal cord stimulation plus optimal medical management with optimal medical management alone in patients with failed back surgery syndrome and predominant low back pain. METHOD/DESIGN: Patients will be recruited in approximately 30 centers across Canada, Europe, and the United States. Eligible patients with low back pain exceeding leg pain and an average Numeric Pain Rating Scale score ≥5 for low back pain will be randomized 1:1 to spinal cord stimulation plus optimal medical management or to optimal medical management alone. The investigators will tailor individual optimal medical management treatment plans to their patients. Excluded from study treatments are intrathecal drug delivery, peripheral nerve stimulation, back surgery related to the original back pain complaint, and experimental therapies. Patients randomized to the spinal cord stimulation group will undergo trial stimulation, and if they achieve adequate low back pain relief a neurostimulation system using the Specify® 5-6-5 multi-column lead (Medtronic Inc., Minneapolis, MN, USA) will be implanted to capture low back pain preferentially in these patients. Outcome assessment will occur at baseline (pre-randomization) and at 1, 3, 6, 9, 12, 18, and 24 months post randomization. After the 6-month visit, patients can change treatment to that received by the other randomized group. The primary outcome is the proportion of patients with ≥50% reduction in low back pain at the 6-month visit. Additional outcomes include changes in low back and leg pain, functional disability, health-related quality of life, return to work, healthcare utilization including medication usage, and patient satisfaction. Data on adverse events will be collected. The primary analysis will follow the intention-to-treat principle. Healthcare use data will be used to assess costs and long-term cost-effectiveness. DISCUSSION: Recruitment began in January 2013 and will continue until 2016. TRIAL REGISTRATION: Clinicaltrials.gov: NCT01697358 (http://www.clinicaltrials.gov).

Successful peripheral nerve field stimulation for thoracic radiculitis following Brown-Sequard syndrome.

OBJECTIVE: The objective of this study is to present a novel approach to the treatment of thoracic radiculitis following Brown-Sequard syndrome with peripheral nerve field stimulation (PNFS). Furthermore, we endeavor to discuss the role of PNFS in the management of refractory neuropathic pain conditions including post-traumatic and post-surgical neuropathy particularly with regards to the post-surgical spine. MATERIALS AND METHODS: Presented is a 57-year-old man with history of thoracic microdiscectomy resulting in Brown-Sequard syndrome presented with chronic post-operative thoracic radicular pain radiating to the abdomen, refractory to conservative management. The patient underwent three intercostal nerve blocks from T7 to T9 with transient symptomatic relief. The patient's options were limited to chemomodulation, neuromodulation, or selective intercostal nerve surgical neurectomy. He subsequently underwent a PNFS trial and reported >75% pain reduction. Permanent percutaneous PNFS electrodes were implanted subcutaneously over the right T7 and T9 intercostal nerves and replicated the trial results. RESULTS: Neuromodulation produced pain relief with >90% improvement in pain compared with baseline both during the trial and following permanent implantation of the PNFS system. CONCLUSION: Chronic radicular pain may be difficult to manage in the post-surgical patient and often requires the use of multiple therapeutic modalities. In this case, we successfully utilized PNFS as it demonstrated greater technical feasibility when compared with dorsal column stimulation and repeat surgery; therefore, it may be considered for the management of post-surgical neuropathy. Further controlled studies are needed to evaluate the efficacy of PNFS as a treatment option.

Acute exacerbation of hereditary coproporphyria mimics early surgical infection following intrathecal pump implantation for chronic abdominal pain: A case report.

OBJECTIVE: Pain physicians should also be aware of rare complications that can occur after intrathecal pump (ITP) placement. One such rare complication includes an acute exacerbation of hereditary coproporphyria (HCP). METHODS: We present a case report that illustrates how an acute exacerbation of HCP can mimic an early surgical post-procedure infection after ITP implantation. RESULTS: The patient's rapid onset of symptoms two hours after the procedure keyed into HCP as the underlying cause, as acute wound infections rarely occur in the several hours following surgery. After symptomatic treatment of her HCP acute exacerbation, the patient clinically improved without the development of further symptoms or adverse sequelae. She reported considerable pain relief with the implanted drug delivery system. CONCLUSION: In a setting with multiple confounders, a methodical history and physical examination, close monitoring, and a comprehensive understanding of potential complications can prevent unnecessary ITP extraction and streamline the delivery of appropriate care.

Treatment of pain in Dercum's disease with Lidoderm (lidocaine 5% patch): a case report.

INTRODUCTION: Dercum's disease is a rare disorder characterized by multiple painful subcutaneous lipomas on the trunk and extremities. It most commonly occurs in obese, postmenopausal women. The pain associated with this condition is postulated to arise from enlarging lipomas producing pressure on peripheral nerves, thereby initiating pain and sometimes paresthesias. Treatment has been challenging due to the rarity of this condition. CASE: A patient with Dercum's disease successfully treated with transdermal lidocaine 5% patches. The patient's pain was initially rated as an 8/10. At follow-up examination after 1 month, the patient rated her pain as 3/10--a >60% reduction in pain; this pain reduction persisted at subsequent 1-month follow-up intervals. CONCLUSION: Current therapeutic options in the treatment of Dercum's disease have proven either ineffective or cumbersome. The use of transdermal lidocaine is a safe and non-invasive treatment modality that has been efficacious in alternate forms. The use of this medication might prove preferable to more invasive or risky treatment and warrants further investigation.

Biochemicals associated with pain and inflammation are elevated in sites near to and remote from active myofascial trigger points.

OBJECTIVES: To investigate the biochemical milieu of the upper trapezius muscle in subjects with active, latent, or absent myofascial trigger points (MTPs) and to contrast this with that of the noninvolved gastrocnemius muscle. DESIGN: We used a microanalytic technique, including needle insertions at standardized locations in subjects identified as active (having neck pain and MTP), latent (no neck pain but with MTP), or normal (no neck pain, no MTP). We followed a predetermined sampling schedule; first in the trapezius muscle and then in normal gastrocnemius muscle, to measure pH, bradykinin, substance P, calcitonin gene-related peptide, tumor necrosis factor alpha, interleukin 1beta (IL-1beta), IL-6, IL-8, serotonin, and norepinephrine, using immunocapillary electrophoresis and capillary electrochromatography. Pressure algometry was obtained. We compared analyte concentrations among groups with 2-way repeated-measures analysis of variance. SETTING: A biomedical research facility. PARTICIPANTS: Nine healthy volunteer subjects. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Preselected analyte concentrations. RESULTS: Within the trapezius muscle, concentrations for all analytes were higher in active subjects than in latent or normal subjects (P<.002); pH was lower (P<.03). At needle insertion, analyte concentrations in the trapezius for the active group were always higher (pH not different) than concentrations in the gastrocnemius muscle. At all times within the gastrocnemius, the active group had higher concentrations of all analytes than did subjects in the latent and normal groups (P<.05); pH was lower (P<.01). CONCLUSIONS: We have shown the feasibility of continuous, in vivo recovery of small molecules from soft tissue without harmful effects. Subjects with active MTPs in the trapezius muscle have a biochemical milieu of selected inflammatory mediators, neuropeptides, cytokines, and catecholamines different from subjects with latent or absent MTPs in their trapezius. These concentrations also differ quantitatively from a remote, uninvolved site in the gastrocnemius muscle. The milieu of the gastrocnemius in subjects with active MTPs in the trapezius differs from subjects without active MTPs.