Pain Practice最新文献

Introduction: Placement of a spinal cord stimulator (SCS) is a neuromodulatory technique with several indications, including persistent spinal pain syndrome type 2 (PSPS2), painful diabetic neuropathy, non-surgical chronic low back pain, and complex regional pain syndrome. SCS is conventionally placed in a caudal to cranial fashion (anterograde), yet there are cases such that spinal fusion hardware and adhesions prevent this insertion technique.

Case presentation: Our patient is a 57-year-old man with PSPS2 who had extensive spinal fusion and epidural scarring extending from the sacrum to T10. The patient trialed and failed conservative medical management for his PSPS2 pain, with limited options available for pain relief. The decision was made to place the SCS leads in a retrograde manner at C7-T1, which were then threaded to the T10 level, offering the patient complete relief of back pain and >80% of bilateral lower extremity radicular symptoms.

Conclusion: Here, we present another case in the literature of a permanently placed SCS performed in the retrograde fashion by an interventional chronic pain physician. Though the technique was off label, the retrograde approach offered the patient significant relief when all other treatment modalities failed. Despite the effective use of the retrograde approach, more studies are needed, including guidelines as to when to offer the retrograde approach for patients with inaccessible anatomy for a typical anterograde technique.

Purpose: To determine whether preoperative magnetic resonance imaging (MRI) can reliably determine intraoperative measurements in the Vertiflex Interspinous Spacer (ISS) procedure.

Methods: Patients who underwent Vertiflex ISS with Lumbar Spinal Stenosis (LSS) and a preoperative MRI available in picture archiving and communication system (PACS) between January 2013 to February 2023 were identified retrospectively from the University of Chicago Medical Center Database. An experienced board-certified pain specialist and well-trained 2nd-year medical student independently performed measurements of the interspinous space where Vertiflex ISSs of various sizes are inserted. MRI measurements were taken blinded to intraoperative measurement and ISS implant size used in the procedure. Pearson's correlation, paired T-test, intraclass correlation coefficients (ICC), absolute agreement, and 2-way random effects model were used to determine the relationships between MRI, intraoperative measurement, and ISS size.

Results: A total of 79 patients who underwent the Vertiflex ISS procedure were included in the study. Median Vertiflex ISS size was 10 mm (10-12), mean intraoperative measurement was 11.40 mm (±1.23), and mean MRI measurement was 11.24 mm (±1.44). Mean differences were not significant in intraoperative and MRI measurements (p = 0.271). Pearson's correlation between ISS size and intraoperative measurement was 0.807 (p < 0.001), representing the current best practice model. Pearson's correlation was 0.668 (p < 0.001) between MRI measurement and ISS size and 0.542 (p < 0.001) between MRI and intraoperative measurement. ICC showed good agreement and moderate reliability (0.698) between intraoperative and MRI measurements. Observer interrater ICC agreement of the MRI interspinous space measurement was 0.95 (p < 0.001).

Conclusions: Measuring interspinous space on MRI yielded, on average, a value smaller than the intraoperative measurement in Vertiflex ISS procedures, but the mean differences were not significant. Good agreement and moderate reliability were found between observer MRI and surgeon intraoperative measurements, suggesting MRI can evaluate the intraoperative space for the Vertiflex ISS procedure. Preoperative MRI measurement may help decrease complications by aiding in surgical decision-making through providing a reference for intraoperative measurements. Further prospective study is necessary to determine if preoperative MRI measurement can predict and potentially replace the need for intraoperative measurement.

Objectives: In the last 20 years, we have seen the flourishing of multiple treatments targeting the dorsal root ganglion (DRG) for pain. However, there is concern regarding the variation in the location of the DRG, which could influence the long-term clinical outcomes. The aim of this work was to determine the exact position of the DRG in the spine and propose a pre-surgical planning.

Materials and methods: A systematic search was conducted following the principles recommended by PRISMA. Search terms "ganglia," "DRG," "dorsal root ganglia, anatomy," "radiological," "neuromodulation," "dorsal root ganglion stimulation" (PubMed, Scopus, Medline, Web of Science, and Embase) were identified 177 articles and subjected to the selection criteria (inclusion/exclusion) based on the independent review of the abstracts.

Results: Eighteen articles were selected (seven anatomical dissections on cadavers, five radiological studies, and six narrative reviews).

Discussion: Percutaneous procedure targeting the DRG for the treatment of chronic pain requires preoperative planning independent to the study of the etiology of pain. The DRG should be typified using magnetic resonance imaging. We propose a preoperative evaluation scale based on four specific items: A-position in the vertebral canal, B-position of the DRG within the foramen, C-number of ganglia in the root, and D-ratio (proportion) of foramen/DRG.

Conclusion: Percutaneous treatments for chronic pain directed at the DRG are effective. Clinical outcomes depend of good preoperative planning that allows for optimizing its effects. We propose a DRG morphology evaluation scale useful for the planning process prior to any treatment directed at the ganglion.

Objectives: Placebo effects can relieve acute and chronic pain in both research and clinical treatments by learning mechanisms. However, the application of placebo-based treatment strategies in routine medical care is questioned. The current study investigated the opinions of patients with fibromyalgia and healthy controls regarding learning of placebo effects and their practical applications.

Method: An online survey asked 158 age- and sex-matched adult patients and controls (79 per group) to rate the perceived influence of various placebo learning mechanisms on pain relief, and the acceptability and perceived effectiveness of placebo-based strategies (open-label, closed-label, dose-extending, and treatment-enhancing strategies). Respondents' knowledge about placebo effects was obtained through a 7-item quiz.

Results: The groups did not differ in the perceived influence of placebo learning mechanisms on pain relief (p = 0.217). Controls considered closed-label and treatment-enhancing strategies more acceptable than patients (p = 0.003 and p < 0.001), whereas controls perceived all strategies more effective. In both groups, closed-label strategies were significantly less acceptable than any other strategy (p-values < 0.001), and treatment-enhancing or dose-extending strategies were most acceptable. Higher acceptability was predicted by higher perceived effectiveness ratings (p < 0.001). Also, increased placebo knowledge was related to higher acceptability (p = 0.03) and perceived effectiveness (p < 0.001).

Discussion: This survey suggests that both the medical history of patients and knowledge about placebo effects affect the acceptability and perceived effectiveness of placebo-based strategies. Furthermore, strategies that are transparent, assumed effective, or combined with existing medical treatments are deemed most acceptable. Keeping these factors in mind is essential for the clinical implementation of placebo-based strategies in routine medical care.

Objectives: Chronic pain is multifactorial and has large social and economic costs. Comprehensive pain management through an interdisciplinary approach addressing the biopsychosocial model of pain is beneficial. The purpose of this study was to assess the feasibility and functional outcomes following participation in the 8-week virtual interdisciplinary Functional Integrative Restoration (FINER) program.

Design: Cohort study.

Setting: Virtual platform (Zoom) utilized by participants and clinicians within a large academic institution.

Subjects: 44 individuals with chronic pain meeting study criteria who participated in the virtual FINER program from September 2021 to April 2023 were included in final analysis.

Methods: Participants attended twice weekly seminars and group sessions focused on pain education, lifestyle medicine, integrative medicine, and psychological therapies virtually and completed pre- and post-program surveys. Outcomes included the Pain Catastrophizing Scale (PCS), Tampa Scale of Kinesiophobia (TSK), and Patient-Reported Outcomes Measurement Information System-29 (PROMIS-29). Qualitative feedback was also obtained.

Results: From September 2021 to April 2023, 44 adult FINER participants with chronic low back and/or neck pain completed pre- and post-intervention surveys. We observed significant improvements in PCS, TSK, and various domains of the PROMIS-29, including pain interference, participation, physical function, and sleep, with modest effect sizes.

Conclusions: The FINER program reduced self-reported functional outcomes related to the participants' chronic pain. Positive qualitative feedback from FINER participants suggested mental and physical health benefits. Future investigation will include a larger cohort and will deploy active (patient-reported outcomes) and passive (mobility and sociability) digital measures to further characterize functional changes.

Introduction: Prior to the permanent implant of a spinal cord stimulator, patients typically undergo a screening trial using a percutaneously placed lead to ensure adequate response. However, due to several factors, patients may not be candidates for this screening trial and therefore instead undergo a "permanent trial" where either a percutaneous lead or paddle lead is placed using a tunneled extension for the trial, with the intent of conversion to a permanent system. If these patients proceed with an implant, the epidural space is not re-accessed and only an impulse generator (IPG) is needed. Although this technique is commonly employed, there is a paucity of literature describing outcomes with the "permanent trial" methodology. We present here our clinical experience with this technique.

Methods: Participants who underwent permanent trials at a single institution between 2014 and 2020 were identified. Charts were reviewed to collect demographic information, numerical rating score (NRS) data, length of follow-up, revisions, complications, and removals.

Results: A total of 27 patients who underwent permanent trial placement were identified from a database of 762 patients who underwent SCS placement (3.54%). The permanent placement group included 7 paddle trials, 14 percutaneous trials, and 6 dorsal root ganglion (DRG) trials. The reasons for pursuing a permanent trial included previously aborted percutaneous trial (n = 8), inability to hold anticoagulation for a prolonged period (n = 4), previous thoracic spine surgery or presence of thoracic stenosis on MRI (n = 4), and significant medical comorbidities precluding typical percutaneous trial lead placement at a surgery center (n = 3). 24/27 (88.8%) proceeded to permanent implant, and 16/24 (66.7%) were considered responders (greater than 50% reduction in pain) after 3 months. Over an average follow-up of 28.7 months, complications included 1 peri-operative intracranial hemorrhage delaying IPG placement, 2 lead fractures, 1 lead migration, and 1 CSF leak. Three patients required revision surgery for lead migration, lead fracture, and CSF leak, respectively. One patient had his system explanted 25.9 months after initial placement due to increased pain from stimulation.

Conclusion: This study aims to characterize our experience with permanent trials for SCS. Here we demonstrate a higher rate of trial-to-implant conversion than previously documented for traditional percutaneous trials. We show similar rates of revisions and complications, elucidating the important role of permanent SCS trials in high-risk patients.

Introduction: Chronic pain can negatively impact a child's quality of life. Pediatric Intensive Interdisciplinary Pain Treatment (IIPT) programs aim to improve overall functioning despite pain through various rehabilitative strategies. It is, however, unclear whether improved function corresponds to self-reported decrease in pain levels. Hence, the purpose of this study is to examine the relationship between changes in physical function and perceived pain among children with chronic pain who have undergone inpatient IIPT.

Materials and methods: A secondary analysis of pre-existing databases of IIPT from two different inpatient acute rehabilitation programs was carried out. Children and adolescents (N = 309; age = 16.2 ± 2.6; 79% females) with chronic pain who attended on average 4-week inpatient IIPT from Nov 2011 to Jan 2023 were included. Participants completed pain intensity (Numerical Pain Rating Scale) and self-reported function measures (Lower Extremity Functional Scale [LEFS], Upper Extremity Functional Index [UEFI], Canadian Occupational Performance Measure [COPM]-Performance, and COPM-Satisfaction) at admission and discharge.

Results: Change in self-reported physical function was significantly associated with change in pain from admission to discharge. After covariate adjustment, self-reported physical function (per the LEFS, UEFI, COPM-Performance, and COPM-Satisfaction) explained 19.8%, 7.8%, 12.0%, and 8.6% of the variance in change in pain, respectively. These measures of self-reported physical function further distinguished between minimal (<30%) and moderate (≥30%) pain reduction.

Conclusions: Self-reported functional gains during IIPT are associated with greater change in perceived pain. Moreover, measures of self-reported physical function can help identify children at risk of minimal pain reduction post-IIPT.

Introduction: Pain from the cervical facet joints, either due to degenerative conditions or due to whiplash-related trauma, is very common in the general population. Here, we provide an overview of the literature on the diagnosis and treatment of cervical facet-related pain with special emphasis on interventional treatment techniques.

Methods: A literature search on the diagnosis and treatment of cervical facet joint pain and whiplash-associated disorders (WAD) was performed using PubMed, Cochrane, and Embase databases. All relevant literature was retrieved and summarized.

Results: Facet-related pain is typically diagnosed based on history and physical examination of the patients, combined with a diagnostic block (eg, with local anesthetic) of the medial branches innervating the joints. There is no additive value for imaging techniques to diagnose cervical facet pain, but imaging may be used for procedure planning. First-line therapy for pain treatment includes focused exercise, graded activity, and range-of-motion training. Pharmacological treatment may be considered for acute facet joint pain; however, for chronic facet joint pain, evidence for pharmacological treatment is lacking. Considering the lack of evidence for treatment with botulinum toxin, intra-articular steroid injections, or surgery, these interventions are not recommended. Diagnostic blocks are not considered a viable treatment option, though some patients may experience a prolonged analgesic effect. Long-term analgesia (>6 months) has been observed for radiofrequency treatment of the medial branches.

Conclusions: Cervical facet pain is diagnosed based on history, physical examination, and a diagnostic block of the medial branches innervating the painful joints. Conservative management, including exercise therapy, is the first line of treatment. When conservative management does not result in adequate improvement of pain, radiofrequency treatment of the medial branches should be considered, which often results in adequate pain relief.

Objectives: In this study, the spread of methylene blue was compared between an ultrasound-guided Pericapsular Nerve Group (PENG) block and a double injection technique, where the approach towards the inferomedial acetabulum was added to the latter.

Methods: The two techniques were performed in 11 fresh frozen cadavers. The spread was measured after anatomical dissection in which the supplying femoral and obturator nerves were identified.

Results and conclusion: Our study demonstrates adequate staining of the iliac bone with comparable distal and medial spread in both techniques, indicating that the PENG block with a single injection is adequate in blocking the hip capsule with 10 mL local anesthetics. Staining of the femoral nerve occurred in 2/6 specimens after the PENG block, and staining of the obturator nerve in 1 specimen in each group.