Ultrasound-guided fascial plane blocks for post-breast surgery pain syndrome.

INTRODUCTION: Persistent pain following breast surgery is common and may be challenging to treat. In patients refractory to conservative treatments, ultrasound-guided fascial plane blocks of thoracic nerves can be a useful option. RESULTS: This type of neuro blockade technique provides advantages in terms of safety and efficacy that are convenient for physicians managing refractory and complex cases of post-breast surgery syndrome. CONCLUSION: This technical review aims to present an up-to-date summary of the most common ultrasound-guided fascial plane blocks for chronic pain in post-breast surgery patients, provide a detailed technical description of each intervention, and propose preferred injections based on the anatomical location of the pain.

Ultrasound-guided procedures for the management of chronic thoracic back pain: a technical review.

Pain arising from the thoracic region has been reported to be potentially as debilitating as cervical or lumbar back pain, and may stem from a vast number of spinal sources, including zygapophysial, costovertebral and costotransverse joints, intervertebral discs, ligaments, fascia, muscles, and nerve roots. Over the last two decades, the use of ultrasound in interventional spinal procedures has been rapidly evolving, due to the ultrasound capabilities of visualizing soft tissues, including muscle layers, pleura, nerves, and blood vessels, allowing for real-time needle tracking, while also reducing radiation exposure to both patient and physician, when compared to traditional fluoroscopy guidance. However, its limitations still preclude it from being the imaging modality of choice for some thoracic spinal procedures, notably epidural (interlaminar and transforaminal approaches) and intradiscal injections. In this technical review, we provide an overview of five thoracic spinal injections that are amenable to ultrasound guidance. We start by discussing their clinical utility, followed by the relevant topographic anatomy, and then provide an illustrated technical description of each of the procedures discussed: (1) erector spinae plane block; (2) intra-articular thoracic zygapophyseal (facet) joint injection; (3) thoracic medial branch block; (4) costotransverse joint injection; and (5) costovertebral joint injection.

Ultrasound-guided costovertebral joint injection-technique description and fluoroscopy and computerized tomography combined controlled cadaveric feasibility study.

OBJECTIVES: To describe and assess the feasibility of an ultrasound-guided technique for intra-articular injection of the costovertebral joints, in an unembalmed cadaveric specimen, utilizing fluoroscopy and cone beam computerized tomography for confirmation of contrast spread and needle tip position, respectively. METHODOLOGY: A single unembalmed cadaveric specimen was obtained. A single interventionist performed the placement of the needles under ultrasound guidance. Contrast dye was then injected through each of the needles under real-time fluoroscopy. Finally, the specimen was submitted to a cone beam computerized tomography with 3-dimensional acquisition and multiplanar reformatting to assess final needle tip position relative to the costovertebral joints. RESULTS: In total, 18 spinal needles were placed under ultrasound guidance. Fluoroscopy showed 4 distinct patterns of contrast spread: intra-articular in the costovertebral joint (13 levels in total), epidural (1 level), intra-articular in the facet joint of the target level (3 levels), and undetermined (1 level). Cone-beam computerized tomography confirmed 13 out of 18 needles to be adequately placed in the costovertebral joints (72% of the total) and 5 out of the 18 needles to be misplaced: 3 needles were placed in the facet joint of the target level, and 2 needles were placed in the epidural space. CONCLUSIONS: This study suggests that, when performed by experienced interventionists, this technique has an accuracy rate of 72%. Further studies are warranted before these results can be extrapolated to daily clinical practice.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation of the Musculocutaneous Nerve for Refractory Antecubital ElbowPain-Brief Technical Report and Illustrative Case Report.

Chronic pain following distal biceps rupture (DBR) is often nonspecific in that it may arise due to the injury, subsequent surgical repair, or a combination of factors, making the painful symptoms challenging to treat. Peripheral nerve injury in the setting of DBR most commonly affects the musculocutaneous nerve or one of its terminal branches and may lead to chronic neuropathic pain involving the elbow and lateral/radial aspect of the forearm. In this brief technical report, we describe an ultrasound-guided (USG) technique for percutaneous implantation of a peripheral nerve stimulator (PNS) targeting the musculocutaneous nerve, along with an illustrative case report of successful treatment of chronic refractory pain following DBR utilizing this technique. Six months postimplantation, the patient reported a greater than 60% baseline pain intensity reduction, and no complications were noted.

La douleur chronique consécutive à une rupture distale du biceps est souvent non spécifique en ce sens qu'elle peut survenir en raison de la blessure, de la réparation chirurgicale ultérieure, ou d'une combinaison de facteurs, rendant les symptômes douloureux difficiles à traiter. La lésion du nerf périphérique dans le cadre d'une rupture distale du biceps affecte le plus souvent le nerf musculo-cutané ou l'une de ses branches terminales et peut entraîner des douleurs neuropathiques chroniques au niveau du coude et de la face latérale/radiale de l'avant-bras. Dans ce bref rapport technique, nous décrivons une technique guidée par ultrason pour l'implantation percutanée d'un stimulateur nerveux périphérique ciblant le nerf musculo-cutané, ainsi qu'un rapport de cas illustratif du traitement réussi de la douleur réfractaire suite à une rupture distale du biceps en utilisant cette technique. Six mois après l'implantation, le patient a signalé une réduction de plus de 60 % de l'intensité de la douleur initiale, et aucune complication n'a été observée.

Peripheral Nerve Stimulation for Chronic Intractable Neuropathic Pain Following a Brachial Plexus Avulsion Injury: A Case Report.

Brachial plexus avulsion injuries result in permanent motor and sensory deficits, leading to debilitating symptoms. We report the case of a 25-year-old man with chronic pain following right-sided C5-T1 nerve root avulsion without evidence of peripheral nerve injury. His pain was recalcitrant to medical and neurosurgical interventions. However, he experienced substantial (>70%) pain relief with peripheral nerve stimulation targeting the median nerve. These results agree with data suggesting collateral sprouting of sensory nerves occurs following a brachial plexus injury. Further study is needed if we are to understand the mechanisms of the peripheral nerve stimulator as a treatment option.

Pain Associated With Monkeypox Virus: A Rapid Review.

International concerns for another pandemic arose after emerging reports of an ongoing outbreak of the monkeypox virus (MPXV) in Europe and the United States in 2022. Severe pain is one of the most distressing complications for patients in the current outbreak, but there is a general paucity of relevant peer-reviewed medical literature from which to draw clear recommendations on appropriate pain therapies. The Centers for Disease Control recently published a letter in July 2022 urging providers to conduct further studies concerning pain management. Thus, a rapid literature search was conducted in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. A comprehensive search of several databases from inception until August 19, 2022, was conducted. All published studies describing pain in patients who tested positive for MPXV with original data and written in English were included. Sixty-nine studies were initially identified for screening. After initial screening, 27 papers were considered for full-text review, and 15 papers met the inclusion criteria. A total of 1043 positive cases were included in this study. Most patients were men. Treatment options proposed by the authors include acetaminophen, ibuprofen, opioids, lidocaine gel, metamizole, and rectal suppositories containing emollients or steroids with oral laxatives for severe anal pain. Although most cases were mild requiring outpatient treatment, a considerable number of patients were admitted due to serious complications. Severe pain was often the reason to seek medical attention and hospital admission for pain control. Analgesic plans included oral and topical analgesia. In severe cases, pain was managed with opioids. To our knowledge, this rapid review is the first study to comprehensively summarize proposed treatments for pain associated with MPXV. Guidelines may be needed to help direct the best management to avoid morbidity in patients, particularly as adjuvants may play a key role but are not commonly utilized in published reports.

Ultrasound-guided percutaneous peripheral nerve stimulation for chronic refractory neuropathic pain: a unique series.

During the last two decades, with the advent of recent technology, peripheral nerve stimulation has become an appealing modality at the forefront of pain management. In this case series, we document the clinical rationale and technical considerations on three of the most challenging cases, refractory to previous interventions, that were treated by our team with an ultrasound-guided percutaneous peripheral nerve stimulator targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. At the 6-month follow-up, all patients experienced greater than 50% relief of baseline pain, with a near-complete resolution of pain exacerbations. Furthermore, to our knowledge, this is the first report of an ultrasound-guided percutaneous technique of a peripheral nerve stimulator targeting the musculocutaneous and subcostal nerves.

Peripheral nerve stimulation is a new tool used in the treatment of peripheral nerve pain. In this study, we share our experience using this technology in three unusual, difficult-to-treat chronic nerve pain presentations, targeting the musculocutaneous, bilateral greater occipital and subcostal nerves. All patients were asked about how pain levels had changed since the peripheral nerve stimulation device had been implanted. In every case, patients reported a decline in their pain level from day one. After 6 months of peripheral nerve stimulator use, all patients reported a greater than 50% pain relief.

Gender Diversity in Primary Care Sports Medicine Leadership.

ABSTRACT: Diversity, equity, and inclusion have been recognized as important drivers of excellence and innovation in the physician workforce. Given the historical underrepresentation of women in medicine, gender diversity is of interest. In this cross-sectional study, we sought to quantify leadership representation of female physicians in primary care sports medicine settings, including primary care sports medicine fellowship programs, select sports medicine societies, and select sports medicine-related scientific journals. Data were collected by querying the corresponding web site for each fellowship program, society, and journal and analyzed in a descriptive manner. Results showed that fewer female physicians hold primary care sports medicine leadership roles than men do. This work establishes a baseline for female representation in primary care sports medicine leadership; efforts should continue to increase the presence of women in leadership positions.

Ultrasound-Guided Gluteal Fascial Plane Block for the Treatment of Chronic Refractory Greater Trochanteric Pain Syndrome - Technique Description and Anatomical Correlation Study.

INTRODUCTION: Greater trochanteric pain syndrome may often mimic pain generated from other sources. However, it is most commonly caused by gluteus medius and gluteus minimus tendinopathy or tear. The purpose of this technical report was to: 1) describe the ultrasound-guided fascial plane block technique targeting the superior gluteal nerve in the plane between gluteus medius/gluteus minimus to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome; 2) anatomically correlate the procedure with cadaveric dissections demonstrating the structures being imaged and the tissues along the needle trajectory; 3) demonstrate the feasibility of the technique with serial dissection of one cadaveric specimen following injection with color dye. TECHNIQUE DESCRIPTION: The ultrasound-guided fascial plane block targeting the superior gluteal nerve to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome has been outlined with supporting ultrasound scans and anatomical dissections. The cadaveric dissections are correlated to the ultrasound scans of a healthy volunteer and provide visualization of the tissues in the needle trajectory. The feasibility study in a cadaveric specimen showed adequate stain of the superior gluteal nerve without spread to the piriformis muscle belly, the sciatic nerve, or the inferior gluteal nerve. CONCLUSIONS: This ultrasound-guided fascial plane block is a feasible option for blocking the superior gluteal nerve without inadvertent involvement of the sciatic and inferior gluteal nerves. Further randomized controlled clinical trials are necessary to assess the clinical efficacy of the gluteus medius/gluteus minimus fascial plane block to treat moderate-to-severe, chronic, refractory greater trochanteric pain syndrome.

Ultrasound-guided hydrodissection of the superficial peroneal nerve for chronic neuropathic pain: a war veteran's story.

Aim: This case report presents the application of ultrasound-guided hydrodissection of the superficial peroneal nerve to treat chronic refractory neuropathic pain, rated by the patient with an average intensity of 6/10 on the numerical rating scale. Materials & methods: Under ultrasound guidance, the nerve was identified compressed by a herniation of the peroneus brevis. An in-plane hydrodissection was performed using a solution of 10 ml of ropivacaine and methylprednisolone until the epineurium was entirely separated from the surrounding tissue. Results: At the 2-month follow-up, the patient reported a decrease of pain, which he rated a 2/10 on the numerical rating scale. At this point, night-time episodes of moderate pain persisted. The procedure was repeated and at the 6-month follow-up, the patient remained pain free. Conclusion: This case report suggests that consecutive ultrasound-guided hydrodissection techniques might be a valuable option in the treatment of superficial peroneal nerve entrapment neuropathy.

Peripheral neuropathic pain is a debilitating pain condition. Management can be challenging and clinicians often rely on oral medications and surgical options. This case report presents the treatment of a case of longstanding, moderate-to-severe superficial peroneal nerve entrapment neuropathy due to a grenade explosion, with consecutive nerve hydrodissection using a solution containing an anesthetic and a corticosteroid. Immediately after the second procedure and at the 6-month follow-up the patient reported near-total relief.

Autologous Platelet-Rich Plasma Applications in Chronic Pain Medicine: Establishing a Framework for Future Research - A Narrative Review.

BACKGROUND: During the last decades, platelet-rich plasma has been studied for the treatment of multiple chronic pain conditions, in addition to being employed in the enhancement of healing after tissue injury. OBJECTIVE: To establish a framework for future research regarding the utilization of platelet-rich plasma in the treatment of chronic tissue injuries. METHODS: Preclinical and clinical studies from 2000-2020 relevant to applications of platelet-rich plasma for the treatment of chronic pain conditions were extracted from PubMed and Medline databases. The studies were analyzed on the basis of the study population, type of intervention, method of platelet-rich plasma preparation, the number of treatments administered, the timeframe of injections, and clinical outcomes. RESULTS: Although several preclinical studies and double-blind, randomized trials have shown promising results in the application of platelet-rich plasma for the treatment of multiple chronic pain conditions, various studies have also reported controversial results. Additionally, the methods employed for obtaining the platelet-rich plasma have not been standardized between studies, resulting in different concentrations of blood components between the preparations utilized. Moreover, differences between studies were also found regarding the number of injections administered per treatment. CONCLUSIONS: Future research addressing the utilization of platelet-rich plasma in the treatment of chronic pain conditions should focus on shedding light on the following major questions: a) Is there a dose-effect relation between the platelet count and the clinical efficacy of the preparation?; b) What pathology determinants should be considered when selecting between leukocyte-enriched and leukocyte-depleted concentrates?; c) What is the role of platelet activation methods on the clinical efficacy of platelet-rich plasma?; d) Is there an optimal number of injections and time frame for application of multiple injection treatment cycles?; e) Does the addition of local anesthetics affect the clinical efficacy of platelet-rich plasma?; and f) Is there potential for future platelet-rich plasma applications for the treatment of neuropathic pain of peripheral origin?

Investigation of Janus Kinase (JAK) Inhibitors for Lung Delivery and the Importance of Aldehyde Oxidase Metabolism.

The Janus family of tyrosine kinases (JAK1, JAK2, JAK3, and TYK2) play an essential role in the receptor signaling of cytokines that have been implicated in the pathogenesis of severe asthma, and there is emerging interest in the development of small-molecule-inhaled JAK inhibitors as treatments. Here, we describe the optimization of a quinazoline series of JAK inhibitors and the results of mouse lung pharmacokinetic (PK) studies where only low concentrations of parent compound were observed. Subsequent investigations revealed that the low exposure was due to metabolism by aldehyde oxidase (AO), so we sought to identify quinazolines that were not metabolized by AO. We found that specific substituents at the quinazoline 2-position prevented AO metabolism and this was rationalized through computational docking studies in the AO binding site, but they compromised kinome selectivity. Results presented here highlight that AO metabolism is a potential issue in the lung.

Reconstruction of the three-dimensional beat pattern underlying swimming behaviors of sperm.

 The eukaryotic flagellum propels sperm cells and simultaneously detects physical and chemical cues that modulate the waveform of the flagellar beat. Most previous studies have characterized the flagellar beat and swimming trajectories in two space dimensions (2D) at a water/glass interface. Here, using refined holographic imaging methods, we report high-quality recordings of three-dimensional (3D) flagellar bending waves. As predicted by theory, we observed that an asymmetric and planar flagellar beat results in a circular swimming path, whereas a symmetric and non-planar flagellar beat results in a twisted-ribbon swimming path. During swimming in 3D, human sperm flagella exhibit torsion waves characterized by maxima at the low curvature regions of the flagellar wave. We suggest that these torsion waves are common in nature and that they are an intrinsic property of beating axonemes. We discuss how 3D beat patterns result in twisted-ribbon swimming paths. This study provides new insight into the axoneme dynamics, the 3D flagellar beat, and the resulting swimming behavior.

Revisiting the Genicular Nerve Block: An Up-to-Date Guide Utilizing Ultrasound Guidance and Peripheral Nerve Stimulation - Anatomy Description and Technique Standardization.

BACKGROUND: Over the last decade, several authors have reported that percutaneous peripheral nerve stimulation (PNS) can be used to assist in verifying the position of the procedure needle tip in relation to nerve structures, and that the combined technique using both ultrasound (US) guidance and PNS may serve as a reliable method for confirmation of the correct position of the procedure needle tip. It has also been reported that, when combined with US guidance, PNS may increase the success rate of pain management interventions. OBJECTIVES: The aim of this technical report was to standardize an effective and easy to learn illustrated step-by-step technical approach to nerve identification during US-guided genicular nerve blocks, using percutaneous PNS as a verification instrument for procedure needle tip location. STUDY DESIGN: This technical protocol was developed based on the results of the authors' most recent cadaveric study on the innervation of the knee joint capsule. The technique was developed and tested by 4 different interventionists with different levels of expertise in US-guided procedures. SETTING: The cadaveric study of the knee joint capsule innervation was performed at the laboratory of the Division of Anatomy of one institution. The technical protocol using US and PNS was later developed at the medical simulation center of a different institution. METHODS: A team of anatomists from a division of anatomy of one institution performed the cadaveric study on the innervation of the knee joint capsule. A team of physicians then developed the step-by-step approach to this technical protocol at the medical simulation center of  a different institution. Finally, the illustrated step-by-step approach was tested by 4 different interventionists with different levels of expertise in US-guided procedures (1 beginner-level user; 1 intermediate-level user; 2 expert-level users), using a portable percutaneous PNS and 2 different US transducers at 2 different institutions. RESULTS: This technical protocol was successfully developed based on the results of the cadaveric study on the innervation of the knee joint capsule. Additionally, it was later successfully tested by interventionists with various levels of expertise utilizing different US equipment at separate institutions. LIMITATIONS: By combining US and nerve stimulation, this protocol requires the availability of both US equipment and necessary equipment for nerve stimulation that must all be made available in the sterile field. Another potential disadvantage is that nerve stimulation controls and the US image screen are generally located on 2 separate display panels, which could cause difficulty with visualization and simultaneous calibration for 2 individual devices. CONCLUSIONS: Our illustrated step-by-step technical protocol can be effectively and safely utilized as a reliable method of training, by which physicians with little to moderate US experience can improve their skills in accurately identifying the genicular nerves while performing US-guided examinations with the intent of executing a peripheral nerve block.

Counting ribs and thoracic levels under ultrasound: a systematized technical protocol for both posterior and anterior approaches.

Over the last two decades, the clinical applications of diagnostic and interventional ultrasound have expanded rapidly. When analyzing the chest wall and thoracic region, ultrasound has previously been shown to reliably identify chest wall pathologies like rib fracture and slipping rib syndrome, as well as having fundamentally changed perioperative management and patient outcomes after the emergence of point-of-care ultrasound. In addition, ultrasound guidance has recently become more popular for multiple blocks in the field of regional anesthesia and pain medicine. In this technical report, we systematize an ultrasound-guided protocol for counting ribs and thoracic levels for both posterior and anterior approaches, which does not require level confirmation by fluoroscopy. With this protocol, we hope to create an effective educational resource to support physicians from any specialty background as they engage in point-of-care ultrasound applications in the thoracic region.

Basal Ganglia versus Peripheral Infarcts: Predictive Value of Early Fiber Alterations.

BACKGROUND AND PURPOSE: Impairment of fiber integrity of the corticospinal tract in the subacute and chronic phases after ischemic stroke has been linked to poor motor outcome. The aim of the study was an assessment of fiber integrity in the acute poststroke phase and an evaluation of its association with the clinical course dependent on the infarction pattern (subtypes: peripheral versus basal ganglia infarction). MATERIALS AND METHODS: All patients who underwent mechanical recanalization of a large-vessel occlusion in the anterior circulation and postinterventional DTI were included (n = 165). The fractional anisotropy index of the patient-specific corticospinal tract within the posterior limb of the internal capsule was correlated to clinical parameters (NIHSS scores/mRS at 90 days), and the interaction of stroke subtype (peripheral infarcts versus basal ganglia infarction) was tested in a moderation analysis. RESULTS: The fractional anisotropy index was reduced in the acute poststroke phase with a correlation to clinical presentation, especially in case of peripheral infarcts (eg, with the NIHSS motor subscore: r = -0.4, P < .001). This correlation was absent for basal ganglia infarction (r = -0.008, P > .05). There was a significant association between the fractional anisotropy index and clinical outcome (mRS after 90 days, P < .01), which is moderated by stroke subtype with significant effects only for peripheral infarcts. CONCLUSIONS: Corticospinal tract abnormalities can be observed in the early stage after mechanical recanalization and have prognostic capacity. This finding increases the clinical value of early DTI imaging parameters. Because the effects observed were limited to peripheral infarcts, further and longitudinal evaluation of fiber integrities within basal ganglia infarction is required.

A short history of thrombectomy - Procedure and success analysis of different endovascular stroke treatment techniques.

BACKGROUND: The historical development of interventional stroke treatment shows a wide variation of different techniques and materials used. Thus, the question of the present work is whether the technical and procedural differences of thrombectomy techniques lead to different technical and clinical results. METHODS AND RESULTS: Analysis of a mixed retrospective/prospective database of all endovascular treated patients with an occlusion of the Carotid-T or M1 segment of the MCA at a single comprehensive stroke center since 2008. Patients were classified regarding the technical approach used. Six hundred sixty-eight patients were available for the final analysis. Reperfusion rates ranged between 56% and 100% depending on the technical approach. The use of balloon guide catheters and most recently the establishment of combination techniques using balloon guide catheters, aspiration catheters and stent retrievers have shown a further significant increase in the rates of successful recanalization, full recanalization and first-pass recanalization. Additionally, the technical development of interventional techniques has led to a subsequent drop in complications, embolization into previously unaffected territories in particular. CONCLUSION: Technical success of MT has improved substantially over the past decade owing to improved materials and procedural innovations. Combination techniques including flow modulation have emerged to be the most effective approach and should be considered as a standard of care.Level of evidence: Level 3, retrospective study.

Thrombus Histology of Basilar Artery Occlusions : Are There Differences to the Anterior Circulation?

BACKGROUND: For patients with acute vessel occlusions of the anterior circulation histopathology of retrieved cerebral thrombi has been reported to be associated to stroke etiology. Due to the relatively small incidence of posterior circulation stroke, exclusive histopathologic analyses are missing for this subgroup. The aim of the study was to investigate thrombus histology for patients with basilar artery occlusions and uncover differences to anterior circulation clots with respect to underlying etiology. METHODS: A total of 59 basilar thrombi were collected during intracranial mechanical recanalization and quantitatively analyzed in terms of their relative fractions of the main constituents, e.g. fibrin/platelets (F/P), red (RBC) and white blood cells (WBC). Data were compared to histopathological analyses of 122 thrombi of the anterior circulation with respect to underlying pathogenesis. RESULTS: The composition of basilar thrombi differed significantly to thrombi of the anterior circulation with an overall higher RBC amount (median fraction in % (interquartile range):0.48 (0.37-0.69) vs. 0.37 (0.28-0.50), p < 0.001) and lower F/P count (0.45 (0.21-0.58) vs. 0.57 (0.44-0.66), p < 0.001). Basilar thrombi composition did not differ between the different etiological stroke subgroups. CONCLUSION: The results depict a differing thrombus composition of basilar thrombi in comparison to anterior circulation clots with an overall higher amount of RBC. This may reflect different pathophysiologic processes between anterior and posterior circulation thrombogenesis, e.g. a larger proportion of appositional thrombus growth in the posterior circulation.

Ultrasound-Guided Percutaneous Peripheral Nerve Stimulation for the Treatment of Chronic Intractable Pain Originating From a Lipofibromatous Hamartoma of the Median Nerve.

This case report presents an application of peripheral nerve stimulation to the median nerve to treat a patient with intractable pain due to a lipofibromatous hamartoma of the left upper extremity. Ultra high-frequency ultrasound was used to determine the boundaries of the hamartoma. The patient then underwent an ultrasound-guided implantation of 2 stimulator electrodes distal to the elbow along the median nerve with stimulation coverage achieved at 1.2 and 1.4 mA, respectively. After an uneventful procedure, the pain score immediately decreased from 9 out of 10 to less than 6 on a numeric rating scale. Two weeks after the procedure, the patient reported substantial pain relief, with an average pain level of 5 to 6 out of 10. Twelve months after implantation, the patient maintained significant pain relief, rating her average pain level as a 4 to 6 out of 10. Placement of a percutaneous peripheral nerve stimulator was safe and effective with no adverse events being reported at the 12-month follow-up.