Multifidus atrophy and/or dysfunction following lumbar radiofrequency ablation: A systematic review.

BACKGROUND: Lumbar medial branch nerve radiofrequency ablation (LRFA) is an interventional procedure used to treat chronic lumbar facet joint pain. Because the medial branch nerves also innervate the multifidus muscle, it has been proposed that LRFA may pose a risk of multifidus atrophy and/or dysfunction. However, the quality and level of evidence to answer this clinical question have not been established. Therefore, this review aimed to systematically appraise the literature to discern whether the prevailing evidence substantiates the hypothesis in question. METHODS: A systematic review compliant with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines was performed to evaluate the quality and level of evidence of studies reporting functional and/or structural changes in the multifidus muscle following LRFA. RESULTS: Only five cohort studies met inclusion criteria. Two studies assessed changes in multifidus function following LRFA with confirmed denervation at electromyography and significant reduction in multifidus shear modulus with ultrasound shear wave elastography. Of the four studies that evaluated changes in multifidus structure with magnetic resonance imaging following LRFA, two demonstrated a decrease in cross-sectional area or an increase in fat infiltration, one demonstrated no change, and one revealed an apparent increase. Given the destructive nature attributed to LRFA, some degree of multifidus atrophy and/or dysfunction may be plausible, albeit with a very low certainty that relies on a restricted body of literature of modest quality and with a presence of high bias. CONCLUSION: There is a paucity of studies discussing the potential association between LRFA and multifidus atrophy and/or dysfunction. In light of the shortage of high-quality studies and the absence of standardized protocols to assess both changes in the structure and function of the multifidus subsequent to LRFA, there is a pressing need for more prospective studies with a high methodological rigor to comprehensively address and answer this enduring debate in clinical practice.

Diabetic Neuropathy: Pathophysiology Review.

PURPOSE OF REVIEW: Diabetic neuropathy is a debilitating complication of diabetes mellitus that affects millions of individuals worldwide. It is characterized by nerve damage resulting from prolonged exposure to high blood glucose levels. Diabetic neuropathy may cause a range of symptoms, including pain, numbness, muscle weakness, autonomic dysfunction, and foot ulcers, potentially causing significant impairment to the quality of life for those affected. This review article aims to provide a comprehensive overview of the pathophysiology of diabetic neuropathy. The etiology of diabetic neuropathy will be discussed, including risk factors, predisposing conditions, and an overview of the complex interplay between hyperglycemia, metabolic dysregulation, and nerve damage. Additionally, we will explore the molecular mechanisms and pathways of diabetic neuropathy, including the impact of hyperglycemia on nerve function, abnormalities in glucose metabolism, the role of advanced glycation end products (AGEs), and inflammatory and immune-mediated processes. We will provide an overview of the various nerve fibers affected by diabetic neuropathy and explore the common symptoms and complications associated with diabetic neuropathy in the pain medicine field. RECENT FINDINGS: This review highlights advances in understanding the pathophysiology of diabetic neuropathy as well as reviews potential novel therapeutic strategies and promising areas for future research. In conclusion, this review article aims to shed light on the pathophysiology of diabetic neuropathy, its far-reaching consequences, and the evolving strategies for prevention and management. In understanding the mechanisms of diabetic neuropathy and the ongoing research in this area, healthcare professionals can better serve patients with diabetes, ultimately improving well-being and reducing complications.

Cervical Spinal Cord Stimulation: A Review.

PURPOSE OF REVIEW: This literature review critically examines existing studies on cervical spinal cord stimulation (cSCS) for the treatment of chronic pain. The objective is to evaluate the current evidence, identify knowledge gaps, and collate data to inform clinical decision-making and suggest future research avenues. The review covers indications, contraindications, surgical and anesthetic approaches, trials, efficacy, and complications of cSCS. RECENT FINDINGS: Recent advancements highlight the evolving role of cSCS in chronic pain management. New neuromodulation techniques involve optimal placement of leads based on the pain's innervation level, maximizing therapeutic outcomes. Contemporary studies underscore the broadening benefits of cSCS, including enhanced functional abilities and sleep quality. However, alongside these innovations come challenges; emerging data bring attention to complications such as hardware issues and infections. Significantly, modern research emphasizes the crucial role of accurate patient selection, factoring in prior therapy responses and comprehensive evaluations. cSCS emerges as a promising tool for chronic pain management, with benefits beyond mere pain relief. As surgical techniques, patient selection criteria, and postoperative care refine, the potential of cSCS expands to benefit a broader patient demographic. However, further comprehensive research is necessary to enhance its application, validate its role earlier in treatment, and ultimately ameliorate the lives of those with chronic pain.

Informed Consent for Spine Procedures: Best Practice Guideline from the American Society of Pain and Neuroscience (ASPN).

Introduction: The evolution of treatment options for painful spinal disorders in diverse settings has produced a variety of approaches to patient care among clinicians from multiple professional backgrounds. The American Society of Pain and Neuroscience (ASPN) Best Practice group identified a need for a multidisciplinary guideline regarding appropriate and effective informed consent processes for spine procedures. Objective: The ASPN Informed Consent Guideline was developed to provide clinicians with a comprehensive evaluation of patient consent practices during the treatment of spine pathology. Methods: After a needs assessment, ASPN determined that best practice regarding proper informed consent for spinal procedures was needed and a process of selecting faculty was developed based on expertise, diversity, and knowledge of the subject matter. A comprehensive literature search was conducted and when appropriate, evidence grading was performed. Recommendations were based on evidence when available, and when limited, based on consensus opinion. Results: Following a comprehensive review and analysis of the available evidence, the ASPN Informed Consent Guideline group rated the literature to assist with specification of best practice regarding patient consent during the management of spine disorders. Conclusion: Careful attention to informed consent is critical in achieving an optimal outcome and properly educating patients. This process involves a discussion of risks, advantages, and alternatives to treatment. As the field of interventional pain and spine continues to grow, it is imperative that clinicians effectively educate patients and obtain comprehensive informed consent for invasive procedures. This consent should be tailored to the patient's specific needs to ensure an essential recognition of patient autonomy and reasonable expectations of treatment.

Nitrate limitation in early Neoproterozoic oceans delayed the ecological rise of eukaryotes.

The early Neoproterozoic Era witnessed the initial ecological rise of eukaryotes at ca. 800 Ma. To assess whether nitrate availability played an important role in this evolutionary event, we measured nitrogen isotope compositions (δ15N) of marine carbonates from the early Tonian (ca. 1000 Ma to ca. 800 Ma) Huaibei Group in North China. The data reported here fill a critical gap in the δ15N record and indicate nitrate limitation in early Neoproterozoic oceans. A compilation of Proterozoic sedimentary δ15N data reveals a stepwise increase in δ15N values at ~800 Ma. Box model simulations indicate that this stepwise increase likely represents a ~50% increase in marine nitrate availability. Limited nitrate availability in early Neoproterozoic oceans may have delayed the ecological rise of eukaryotes until ~800 Ma when increased nitrate supply, together with other environmental and ecological factors, may have contributed to the transition from prokaryote-dominant to eukaryote-dominant marine ecosystems.

A sedimentary record of the evolution of the global marine phosphorus cycle.

Phosphorus (P) is typically considered to be the ultimate limiting nutrient for Earth's biosphere on geologic timescales. As P is monoisotopic, its sedimentary enrichment can provide some insights into how the marine P cycle has changed through time. A previous compilation of shale P enrichments argued for a significant change in P cycling during the Ediacaran Period (635-541 Ma). Here, using an updated P compilation-with more than twice the number of samples-we bolster the case that there was a significant transition in P cycling moving from the Precambrian into the Phanerozoic. However, our analysis suggests this state change may have occurred earlier than previously suggested. Specifically in the updated database, there is evidence for a transition ~35 million years before the onset of the Sturtian Snowball Earth glaciation in the Visingsö Group, potentially divorcing the climatic upheavals of the Neoproterozoic from changes in the Earth's P cycle. We attribute the transition in Earth's sedimentary P record to the onset of a more modern-like Earth system state characterized by less reducing marine conditions, higher marine P concentrations, and a greater predominance of eukaryotic organisms encompassing both primary producers and consumers. This view is consistent with organic biomarker evidence for a significant eukaryotic contribution to the preserved sedimentary organic matter in this succession and other contemporaneous Tonian marine sedimentary rocks. However, we stress that, even with an expanded dataset, we are likely far from pinpointing exactly when this transition occurred or whether Earth's history is characterized by a single or multiple transitions in the P cycle.

Pill Counting as an Intervention to Enhance Compliance and Reduce Adverse Outcomes with Analgesics Prescribed for Chronic Pain Conditions: A Systematic Review.

PURPOSE OF REVIEW: Appropriate use of opioid analgesics is a key concern within the field of pain medicine. Several methods exist to discourage abuse and facilitate effective treatment regimens. Pill counting is often cited as one such method and frequently employed in varying fashions within clinical practice. However, to date, there is no published review of the evidence to support this practice. This was a comprehensive review of the available literature that was conducted with analysis of the efficacy and practical application of pill counting during treatment of chronic pain conditions. RECENT FINDINGS: There is paucity in data regarding pill count importance in pain management. Pill count is a very important tool to monitor compliance of opioids use which in turn can prevent several complications associated with opioid misuse. Pill counting may be used in conjunction with other abuse deterrents, although increased support for this practice requires standardized methods of pill counting and further analysis of its effectiveness.

Ultrasound-Guided Hydrodissection Provides Complete Symptom Resolution in Radial Tunnel Syndrome: A Case Series and Scoping Review on Hydrodissection for Radial Nerve Pathology.

ABSTRACT: This study analyzes the effectiveness of ultrasound-guided hydrodissection (HD) perineural as a treatment for radial tunnel syndrome (RTS). A literature search was performed along with retrospective analysis of local cases to assess outcomes and safety of this procedure. In the case series, surgical candidates, defined as cases with over 80% but temporary relief after diagnostic injection, were treated with ultrasound-guided HD. Of 22 patients who received ultrasound-guided diagnostic injections, 11 proceeded to HD. All HD patients experienced complete and lasting symptom resolution for a minimum of 2 years, and none required surgery. Thorough literature review provided seven studies, which fulfilled inclusion criteria. Sixty-one patients are represented in the literature. All studies reported significant benefit to pain symptoms with HD of radial nerve, with five specifying over 90% improvement. No adverse effects from HD were noted in any study. Ultrasound-guided HD of the radial tunnel has potential to be a surgery sparing treatment for RTS.

Review of Interventional Treatments for Cluneal Neuropathy.

BACKGROUND: The most common presentation of cluneal neuropathy is ipsilateral low back and gluteal pain. Cluneal neuralgia has been described historically in surgical contexts, with much of the description and treatment related to entrapment and decompression, respectively. Treatment options for addressing axial low back pain have evolved with advancements in the field of interventional pain medicine, though clinical results remain inconsistent. Recent attention has turned toward peripheral nerve stimulation. Nonsurgical interventions targeting the superior and medial cluneal nerve branches have been performed in cases of low back and buttock pain, but there is no known review of the resulting evidence to support these practices. OBJECTIVES: In this manuscript we provide a robust exploration and analysis of the available literature regarding treatment options for cluneal neuropathy. We provide clinical manifestations and recommendations for future study direction. STUDY DESIGN: Narrative review. METHODS: This was a systematic, evidence-based narrative, performed after extensive review of the literature to identify all manuscripts associated with interventional treatment of the superior and medial cluneal nerves. RESULTS: Eleven manuscripts fulfilled inclusion criteria. Interventional treatment of the superior and middle cluneal nerves includes blockade with corticosteroid, alcohol neurolysis, peripheral nerve stimulation, radiofrequency neurotomy, and surgical decompression. LIMITATIONS: The supportive evidence for interventions in cluneal neuropathy is largely lacking due to small, uncontrolled, observational studies with multiple confounding factors. There is no standardized definition of cluneal neuropathy. CONCLUSION: Limited studies promote beneficial effects from interventions intended to target cluneal neuropathy. Despite increased emphasis and treatment options for this condition, there is little consensus on the diagnostic criteria, endpoints, and measures of therapeutics, or procedural techniques for blocks, radiofrequency, and neuromodulation. It is imperative to delineate pathology associated with the cluneal nerves and perform rigorous analysis of associated treatment options.

A First Estimate of the Annual Prevalence of Basivertebral Nerve Ablation Candidates in a Spine Clinic.

BACKGROUND: Emerging literature supports the use of basivertebral nerve ablation (BVNA) for a specific cohort of patients with chronic low back pain and Type 1 or Type 2 Modic changes from vertebral levels L3-S1. The early literature warrants further evaluation. Studies establishing the efficacy of BVNA use highly selective patient criteria. OBJECTIVE: Provide a first estimate of the prevalence of BVNA candidates in a spine clinic over a year using the foundational studies patient selection criteria? METHODS: A retrospective review of four fellowhsip trained spine physiatrists patient encounters at a large academic medical center using relevant ICD-10 codes to isolate chronic low back pain without radiating symptoms from January 1, 2019 to January 1, 2020. Charts were then reviewed by a team of physicians for exclusionary criteria from the foundational studies which have demonstrated benefit from BVNA. MRI's from qualifying charts which did not meet exclusionary criteria were then independently reviewed by four physician for localization and characterization of Modic changes. RESULTS: The relevant diagnostic codes query yielded 338 unique patient records. Based on exclusionary criteria or lack of imaging availability, 318 charts were eliminated. The remaining 20 charts qualified for imaging review. There were 11 charts in which there was 100% agreement between all reviewers regarding the presence and either Type 1 or Type 2 Modic changes between vertebral levels L3 to S1. Accordingly, the prevalence of eligibility for BVNA was 3% (11/338, 95% CI 1-5%). CONCLUSION: The population which may benefit from BVNA is small. Our study demonstrated that over a year, the prevalence for BVNA candidacy using the foundational studies criteria was 3% (95% CI 1% - 5%). While physicians may be tempted to use less stringent selection criteria in practice, upon doing so they cannot cite the foundational studies as evidence for the outcomes they expect to achieve. Those outcomes will require more studies which formally assess the benefits of BVNA when selection criteria are relaxed.

Factors involved in applicant interview selection and ranking for chronic pain medicine fellowship.

INTRODUCTION: Applicants to chronic pain medicine fellowship programs often express confusion regarding the importance of various selection criteria. This study sought to elucidate program directors' considerations in applicant selection for fellowship interviews and ranking and to correlate these criteria with match statistics to provide a guide for prospective candidates. METHODS: An electronic survey was sent to all Accreditation Council for Graduate Medical Education-accredited chronic pain fellowship directors. The importance of various applicant characteristics were evaluated and compared with recent match data. RESULTS: Fifty-seven program directors completed the survey. The most important factors involved in applicant interview selection were perceived commitment to the specialty, letters of recommendation from pain faculty, scholarly activities, and leadership experiences. Although completion of a pain rotation was valued highly, experience with procedures was of relatively low importance. There was no preference if rotations were completed within the responders' department. Variability was noted when considering internal applicants or the applicant's geographic location. When citing main factors in ranking applicants, interpersonal skills, interview impression and applicant's fit within the institution were highly ranked by most responders. DISCUSSION: Assessment of an applicant's commitment to chronic pain is challenging. Most responders prioritize the applicant's commitment to chronic pain as a specialty, scholarly activity, participation in chronic pain rotations, pain-related conferences and letters of recommendation from pain faculty. Chronic pain medicine fellowship candidates should establish a progressive pattern of genuine interest and involvement within the specialty during residency training to optimize their fellowship match potential.

Radiofrequency Ablation for Zygapophyseal Joint Pain.

Radiofrequency ablation for spinal zygapophyseal joint pain is a safe and effective procedure in carefully selected patients when an appropriate technique is used. The equipment and techniques for performing this procedure have evolved over the past several decades. Likewise, the selection criteria have been refined to optimize results. This article provides an overview of the epidemiology of zygapophyseal joint pain, patient selection and outcomes data associated with RFA, and risks and contraindications of the procedure.

Lumbar medial branch block progression to radiofrequency neurotomy: A retrospective audit of clinical practice.

Introduction: Chronic axial low back pain due to zygapophysial joint arthropathy is best diagnosed via lumbar medial branch block (MBB). However, the paradigm by which MBB is used to select patients for lumbar radiofrequency neurotomy (RFN) is contested. Dual diagnostic lumbar MBB with a minimum of ≥80% pain relief to diagnose lumbar zygapophysial joint pain are accepted by some Medicare Local Coverage Determination (LCD) as the method for selecting patients for RFN for the management of lumbar zygapophysial joint pain. However, some argue that dual diagnostic MBB and the ≥80% pain relief threshold lack utility in clinical practice, given that those that progress from MBB1 to MBB2 will then flow from MBB2 to RFN without fail. Study: Pragmatic retrospective clinical audit. Objective: Does clinical practice of dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold reduce patient eligibility for RFN after both MBB1 and MBB2? Results: Using dual diagnostic lumbar MBBs and an ≥80% pain improvement diagnostic threshold, 90/167 (54%, 95% CI 46-61%) patients successfully progressed from MBB1 to MBB2. Of those 90 patients, 66 patients (73%, 95% CI 64-82%) successfully progressed from MBB2 to RFN. Both MBB1 and MBB2 impacted the eligibility of the progression of 77/167 (46%, 95% CI 39-54%) patients and 24/90 patients (27%, 95% CI 18-36%), respectively. An additional sub-cohort analysis which included all the patients from the ≥80% pain relief cohort, and those who progressed at the discretion of the providers with 50-79% relief revealed that 124/167 patients (74%, 95% CI 68-81%) successfully progressed from MBB1 to MBB2. Of those 124 patients, 99 patients (80%, 95% CI 73-87%) progressed from MBB2 to RFN. In this laxer criteria cohort, MBB1 and MBB2 impacted the eligibility of the progression of 43/167 patients (26%, 95% CI 19-32%) and 25/124 patients (20%, 95% CI 13-27%), respectively. Conclusion: MBB1 and MBB2 both filtered patients from progression to lumbar RFN using dual MBBs with an ≥80% pain relief criteria. It also held true when using a more relaxed pain relief selection criterion as well. Dual MBB's and ≥80% pain improvement criteria as a selection paradigm led to half as many lumbar RFNs being performed when compared to a single MBB and ≥80% pain improvement criteria. In theory, a more rigid selection paradigm treats less patients but exposes fewer to unnecessary RFNs while a laxer selection paradigm treats more patients but exposes more to unnecessary RFNs.

Systematic review of the effectiveness of caudal epidural steroid injections in the treatment of chronic low back or radicular pain.

Objective: Determine the efficacy, effectiveness, and safety of fluoroscopically- or ultrasound-guided caudal epidural steroid injections (ESIs) with or without catheter placement for the treatment of chronic low back (CLBP), radicular pain, and/or chronic post-surgical back pain (CPSBP). Design: Systematic review. Population: Adults ≥18 years with CLBP, radicular pain, or CPSBP ≥3 months. Intervention: Fluoroscopically- or ultrasound-guided caudal ESI with or without a catheter including epidural neuroplasty. Comparison: Sham, placebo procedure, active standard care treatment, or none. Outcomes: The primary outcome was the proportion of individuals with reduction of pain by â€‹≥ â€‹50%. Secondary outcomes included functional improvement, analgesic use, subsequent spinal surgery, healthcare utilization, and mean improvement in pain. Reported adverse events were also cataloged. Methods: Four reviewers independently assessed publications before January 2, 2022 in PubMed, Ovid MEDLINE, and Scopus. Quality of evidence was evaluated using the Grading of Recommendation, Assessment, Development, and Evaluation (GRADE) framework. Results: Of 364 records screened, 23 publications met inclusion criteria. The success rates for the primary outcome could only be extrapolated from one study. Another study used a composite improvement scale that included pain and functional outcomes. The reported success rates in these two studies ranged from 40 to 58% at three months, 25%-67% at six months, and 58%-61% at one year. Data on secondary outcomes were limited; however, rates of functional improvement as measured by mean improvement in Oswestry Disability Index (ODI) ranged from 2% to 55%. Conclusion: There is moderate-quality evidence that caudal ESIs using an in-dwelling catheter for two days is an effective treatment for pain and dysfunction associated with disc herniation with radicular pain and for CPSBP at three, six, and 12 months. There is low-quality evidence supporting the effectiveness of other caudal ESI techniques for pain and dysfunction associated with central lumbar spinal stenosis with neurogenic claudication, discogenic CLBP, and CLBP without disc herniation or radiculitis.

The interrater reliability of the novel Udby classification of Modic Changes: A first estimate.

Background: Modic change grading is heterogeneous, inconsistent, and lacks a single nomenclature across the published literature. A new method of Modic change classification has been established by Dr. Peter Udby which hopes to unify how Modic changes are classified while also adding grading of the cranial/caudal extent of the Modic change across the vertebral body from the respective endplate involved to best capture the clinically relevant information of Modic changes. Methods: Twenty magnetic resonance images of potential basivertebral nerve ablation candidates were independently reviewed by two board-certified and fellowship trained neuroradiologist and two board-certified and fellowship-trained interventional spine physiatrists for the presence and characterization of Modic changes using the newly described Udby classification. 100% agreement of all four reviewers of Modic change presence, Type, and Udby classification was required to be classified as agreement. There were 480 total data points each with 10 unique choices to compare across the four independent reviewers. Results: The kappa value of their agreement was 0.5899 (95% CI 0.4860-0.6939). Conclusion: This study, requiring unanimous agreement between 4 physicians in application of the Udby classification, demonstrated an interrater reliability score of 0.5899 (95% CI 0.4860-0.6939). While this figure provides a first estimate, larger scale research is necessary before definitive claims regarding the interrater agreement validity of the Udby characterization system may be made.

Interventional Procedures for Vertebral Diseases: Spinal Tumor Ablation, Vertebral Augmentation, and Basivertebral Nerve Ablation-A Scoping Review.

Low back pain is consistently documented as the most expensive and leading cause of disability. The majority of cases have non-specific etiologies. However, a subset of vertebral diseases has well-documented pain generators, including vertebral body tumors, vertebral body fractures, and vertebral endplate injury. Over the past two decades, specific interventional procedures targeting these anatomical pain generators have been widely studied, including spinal tumor ablation, vertebral augmentation, and basivertebral nerve ablation. This scoping review summarizes safety and clinical efficacy and discusses the impact on healthcare utilization of these interventions. Vertebral-related diseases remain a top concern with regard to prevalence and amount of health care spending worldwide. Our study shows that for a subset of disorders related to the vertebrae, spinal tumor ablation, vertebral augmentation, and basivertebral nerve ablation are safe and clinically effective interventions to decrease pain, improve function and quality of life, and potentially reduce mortality, improve survival, and overall offer cost-saving opportunities.

A long-term record of early to mid-Paleozoic marine redox change.

The extent to which Paleozoic oceans differed from Neoproterozoic oceans and the causal relationship between biological evolution and changing environmental conditions are heavily debated. Here, we report a nearly continuous record of seafloor redox change from the deep-water upper Cambrian to Middle Devonian Road River Group of Yukon, Canada. Bottom waters were largely anoxic in the Richardson trough during the entirety of Road River Group deposition, while independent evidence from iron speciation and Mo/U ratios show that the biogeochemical nature of anoxia changed through time. Both in Yukon and globally, Ordovician through Early Devonian anoxic waters were broadly ferruginous (nonsulfidic), with a transition toward more euxinic (sulfidic) conditions in the mid-Early Devonian (Pragian), coincident with the early diversification of vascular plants and disappearance of graptolites. This ~80-million-year interval of the Paleozoic characterized by widespread ferruginous bottom waters represents a persistence of Neoproterozoic-like marine redox conditions well into the Phanerozoic.