Low Back Pain: Guidelines for the Clinical Classification of Predominant Neuropathic, Nociceptive, or Central Sensitization Pain

Treatment for the central sensitization component of lower back pain using systemic manual therapy

OBJECTIVE

The purpose of this study was to analyze treatments for central sensitization (CS) and other contributors to chronic lower back pain (CLBP), using systemic manual therapy (SMT) protocols based on the temporal model for CS (TMCS).

DESIGN

Cohort retrospective multivariate analysis.

METHODS

This study analyzed episode of care and rate of improvement data in 1053 patients, evaluating 715 protocol combinations of SMT.

RESULTS

While 682 (68%) patients reported improvement in overall symptoms, only 583 (53%) reported improvement in the lower back pain complaint. Comorbidities with statistically significant (p < 0.05) association with worse lower back pain outcomes were statin use, anxiety, depression, digestive and urinary issues, smoking and prior surgery. A significantly higher rate of improvement resulted from the use of 43 protocol combinations, which were composed of 19 protocols, a group that includes five protocols including urinary-drainage (UD), Diaphragm-cranial-sinus (DCS), Barral-abdominal-motility (Barral), lower-abdominal-urogenital (LAUG), and Cardiac-cervical-cranial-vascular (CCCV), which were all predicted to treat CS by the TMCS.

DISCUSSION AND CONCLUSIONS

The results of this study support the use of SMT to treat CLBP and reinforce the TMCS hypothesis defining CS as a functional, multifaceted neurophysiological state rather than a purely structural adaptation of the CNS. The lower rate of improvement in CLBP compared to overall improvement and the correlations of worse outcome with certain comorbidities suggests that, in addition to SMT, a multimodal approach for CLBP should favor lifestyle improvements such as smoking cessation, lifelong exercise habits, and a balanced diet over medications and surgery.

Cultural adaptation and psychometric validation of the exercise adherence Rating scale Mexican Spanish version (EARS-Mx)

OBJECTIVE

The aim has been to translate and cross-culturally adapt the Exercise Adherence Rating Scale (EARS) for Mexican Spanish speaking population with non-specific chronic low back pain and assess its psychometric properties.

METHODS

The study had two phases: translation and cultural adaptation, followed by psychometric validation. Reliability was assessed with internal consistency (Cronbach's alpha) and test-retest reliability (intraclass correlation coefficient); validity with construct validity (Spearman's correlation) and factor analysis; sensitivity to change with effect size and standardized response mean difference; feasibility by completion time in seconds; and ceiling/floor effects were calculated.

RESULTS

A total of 161 subjects were included. Cronbach's alpha (0.93; 95% CI 0.92-0.95) indicated good internal consistency, and intraclass correlation (0.95; 95% CI: 0.89-0.97) showed excellent test-retest reliability. Weak correlations between the EARS vs. the Visual Analogue Pain Rating Scale and the Roland Morris Disability Questionnaire were found (r = -0.29 and r = 0.00 respectively). All effect size values indicated that the scale presented a significant sensitivity to change. The average time to complete the EARS-Mx was 219 s. No ceiling or floor effect was detected.

CONCLUSION

The EARS-Mx showed semantic, conceptual, idiomatic, content and operational equivalence with respect to the original scale, and appropriate metric properties of reliability, validity, sensitivity to change and feasibility.

Global burden of low back pain from 1990 to 2021: a comprehensive analysis of risk factors and trends using the Global Burden of Disease Study 2021

BACKGROUND

This study comprehensively assesses low back pain-related risk factors and the global burden from a multi-dimensional perspective, aiming to provide scientific evidence for disease prevention.

METHODS

Data from the Global Burden of Disease (GBD) database spanning from 1990 to 2021 were incorporated into this study. We conducted an analysis of baseline data, as well as gender and age subgroup data. Additionally, we introduced the Age-Period-Cohort (APC) and decomposition analysis models to clarify the independent effects of factors such as age, period, cohort, population growth, population aging and changes in epidemiological trends on the disease burden. The Estimated Annual Percentage Change (EAPC) was used to measure the temporal trends of health indicators. To enhance practical applicability, we constructed a model that integrates frontier analysis with health inequality assessment. Furthermore, the Autoregressive Integrated Moving Average (ARIMA) model was employed to forecast trends in LBP over the next 15 years.

RESULTS

In 2021, the global age-standardized prevalence of low back pain decreased by 11.06% compared to that in 1990. However, the number of affected individuals increased from 386.7 million to 628.8 million. Concurrently, the age-standardized Disability-Adjusted Life Years (DALYs) rate declined by 11.22% relative to 1990, while total DALYs rose from 43,386,225 to 70,156,962. The results derived from multiple models indicate that higher socio-demographic index levels, advancing age, female sex and occupational ergonomics-related factors may contribute to disparities in the burden of low back pain. Furthermore, this unequal health gap appears to be widening over time.

CONCLUSIONS

Disease burden of low back pain exhibit varying manifestations across different regions and temporal dimensions. Higher levels of the Socio-Demographic Index(SDI), increasing age, female gender and adverse occupational ergonomic factors may be important risk elements for the burden of low back pain. Meanwhile, certain changes in epidemiological trends may alleviate this burden to some extent. In the absence of effective intervention measures, the gaps in health inequality engendered by the aforementioned diverse factors are likely to expand continuously. In light of this, it is crucial to actively develop systematic, comprehensive and targeted health prevention strategies.

Association Between Non-spinal Comorbid Medical Conditions and Neuropathic Low Back Pain. - A Further Unravelling of Pain Complexities in the Context of Back Pain

Study DesignProspective cohort study.ObjectiveUnderstanding the complex nature of low back pain (LBP) is crucial for effective management. The PainDETECT questionnaire is a tool that distinguishes between neuropathic (NeP) and nociceptive (NoP) low back pain. Traditionally NeP and NoP have been primarily attributed to patho-anatomical abnormalities within the lumbar spine. However, increasing evidence points to multifaceted involvement, encompassing a range of physical, biomechanical, chemical, and psychosocial factors. The study aimed to determine the independent relationship between NeP as assessed by the PainDETECT questionnaire and non-spinal comorbid medical conditions.MethodsA prospective cohort study was conducted involving 400 patients suffering from chronic LBP (>6months), aged >18 years, who complete the PainDETECT questionnaire and provided responses regarding the presence of any comorbid conditions. A binary logistic regression model was used to analyse the confounding status of comorbid medical conditions and pain severity measured by NRS to determine independent relationships between specific conditions and neuropathic pain.ResultsThe study included 143 and 257 patients suffering from NeP and NoP, respectively. The NeP group had a 38% higher mean numerical rating scale score compared to the NoP group (8.10 ± 1.55 vs 5.86± 2.26, P < 0.001). The odds of developing NeP were 2.9 Exp(B) = 2.844, 95%C.I. [1.426-5.670], P < 0.01), 2.7 (Exp(B) = 2.726, 95%C.I. [1.183-6.283], P < 0.05) and 2.8 (Exp(B) = 2.847, 95%C.I. [1.473-5.503], P < 0.05) times higher in patients suffering from gastrointestinal conditions, rheumatoid arthritis, and depression, respectively.ConclusionNeP as determined by the PainDETECT questionnaire, is associated with gastrointestinal conditions, rheumatoid arthritis, and depression. This pioneering study has shed light on the potential involvement of the gut microbiome as a common factor connecting non-spinal comorbidities and NeP. These findings underscore the importance of formulating personalized management plans tailored to individual pain and medical profiles, rather than relying on a blanket approach to pain management.

Contemporary clinical perspectives on chronic low back pain: The biology, mechanics, etc. underpinning clinical and radiological evaluation

Background

Pain of a chronic nature remains the foremost concern in tertiary spine clinics, yet its elusive nature and quantification challenges persist. Despite extensive research and education on low back pain (LBP), the realm of diagnostic practices lacks a unified approach. Clinically, LBP exhibits a multifaceted character, encompassing conventional assessments of severity and disability, alongside nuanced attributes like pain characterization, duration, and patient expectations. Common instigators of LBP encountered in spine surgical settings comprise degenerated intervertebral discs (IVD), herniated IVD, canal and foraminal stenosis, and spondylolisthesis. However, addressing the root cause necessitates its identification and substantiation through visualization.

Methods

This perspective reviews the diagnostic complexities of LBP. Thorough history-taking and physical examinations offer preliminary insights into the underlying source of pain, whether it arises from discogenic origins, neural compression, or sagittal imbalance. The importance of classifying chronic LBP into the underlying pathophysiology is explored. Emphasis is placed on the necessity of aligning clinical observations with imaging findings to guide personalized treatment strategies.

Results

Currently, there exists a disparity globally between evidence-based recommendations and actual applications. Recent discoveries behind the pathophysiology of pain phenotypes signify the importance of classifying LBP into its neuropathic or nociceptive origins. The pivotal role of radiological investigations in validating clinical findings for an accurate diagnosis cannot be overstated. However, radiology should not operate in isolation; the disconnect between the clinical and radiological realms ultimately benefits neither the patient nor the surgeon. Additionally, more sensitive measures of IVD prolapse and the corresponding inflammatory pathway triggered are required to provide information on the underlying pathophysiological mechanism of pain generation.

Conclusion

This perspective article underscores the imperative fusion of clinical acumen and radiological precision in the intricate landscape of LBP diagnosis. These findings advocate for a paradigm shift towards personalized medicine. By offering a compass for surgeons to navigate this complex terrain and deliver more effective, patient-centered care with targeted interventions this article aims to enhance management outcomes for chronic LBP.

Applying Nociplastic Pain Criteria in Chronic Musculoskeletal Conditions: A Vignette Study

Background/Objectives: The International Association for the Study of Pain (IASP) recently introduced clinical criteria and a grading system to identify nociplastic pain, marking a pivotal step toward improving diagnostic accuracy. This study aimed to evaluate the reliability and validity of the IASP criteria using clinical vignettes, assessing their effectiveness in identifying nociplastic pain in clinical settings. Methods: A reliability and diagnostic accuracy study was conducted using 32 clinical vignettes based on the literature and pre-existing clinical data. The vignettes represented patients with and without the characteristics of nociplastic pain and were reviewed independently by two expert physiotherapists. Inter-rater and intra-rater reliability were evaluated with a 1-month interval between assessments. Criterion validity was analyzed by comparing the IASP criteria against the standardized vignettes as the reference standard. Sensitivity, specificity, and predictive values were calculated to assess diagnostic accuracy. Results: The IASP criteria demonstrated moderate-to-perfect intra-rater agreement (κ = 0.71-1.00, p < 0.05) and weak-to-perfect inter-rater agreement (κ = 0.52-1.00, p < 0.05). Criterion validity was moderate (κ = 0.68), with strong specificity (89.0%) and moderate sensitivity (69.0%). Positive and negative predictive values were high at 81.8% and 81.0%, respectively, supporting the criteria's accuracy in identifying and excluding nociplastic pain. Conclusions: The IASP criteria for nociplastic pain exhibited satisfactory reliability and criterion validity in this preliminary study, particularly after initial rater familiarization. Future research should evaluate their application in real-world clinical settings, explore concurrent and prognostic validity, and involve a broader range of raters to enhance generalizability.

Is the Central Sensitization in Chronic Nonspecific Low Back Pain Structural Phenomenon or Psychological Reaction? A Narrative Review

Lower back pain (LBP) is a common condition affecting primarily populations in developed countries, placing a significant burden on public health systems around the world. A high rate of pain recurrence increases the risk of developing a chronic syndrome and the occurrence of complex psychosocial and professional problems. Symptoms lasting longer than 12 weeks are associated with the risk of sleep problems, depression, and anxiety. In the 21st century, the development of knowledge about central sensitization (CS) to pain allowed for a better understanding of the pathomechanism of pain and the transformation of LBP into a chronic form. Patients with chronic severe pain often experience accompanying symptoms such as fatigue, depression, anxiety, sleep disorders, appetite disorders, flatulence, dyspepsia, and dizziness-these are part of the picture of CS. The article presents a narrative, chronological review of reports covering the current state of knowledge on the possibility of assessing central sensitization and its impact on low back pain. The authors also attempt to answer the question posed in the title. CS can be seen as an excessive reactivity of nociceptive neurons in the central nervous system to normal or subthreshold afferent chronic stimuli in people with certain mental predispositions.

Classifying Low Back Pain Through Pain Mechanisms: A Scoping Review for Physiotherapy Practice

Background: Low back pain (LBP) is a leading cause of disability worldwide, often driven by distinct pain mechanisms: nociceptive, neuropathic, and central sensitization. Accurate classification of these mechanisms is critical for guiding effective, targeted treatments. Methods: A scoping review was conducted following the Joanna Briggs Institute methodology and reported according to PRISMA-ScR guidelines. A comprehensive literature search was performed in MEDLINE, Cochrane CENTRAL, Scopus, PEDro, and Web of Science. Eligible studies included adults with LBP and focused on clinical criteria for classifying pain mechanisms. Data on study methods, population characteristics, and outcomes were extracted and synthesized. Results: Nine studies met the inclusion criteria. Nociceptive pain was characterized by localized symptoms proportional to mechanical triggers, with no neurological signs. Neuropathic pain was associated with burning sensations, dysaesthesia, and a positive neurodynamic straight leg raise (SLR) test. Central sensitization featured widespread pain, hyperalgesia, and disproportionate symptoms. Tools such as painDETECT, DN4, and the Central Sensitisation Inventory (CSI) were validated for neuropathic and central sensitization pain. Central sensitization and neuropathic pain were linked to greater disability and psychological distress compared to nociceptive pain. Conclusions: This review aims to provide a historical perspective on pain mechanism classifications and to explore how previous frameworks have influenced current diagnostic concepts in physiotherapy practice. By synthesizing key clinical criteria used to differentiate between nociceptive, neuropathic, and central sensitization pain, this review proposes a practical framework to improve the accuracy of pain classification in clinical settings.

Neuropathic Component Characteristics in Chronic Secondary Musculoskeletal Pain After Postmenopausal Osteoporotic Fractures: A Pilot Cross-Sectional Study

Background: The neuropathic characteristics of pain occurring after an osteoporosis (OP)-related fracture are often under-recognized. The aim of this pilot study is to identify, in patients suffering from pain localized on the site of a previous osteoporotic fracture, the presence of neuropathic characteristics, their medical management, and their impact on quality of life. Methods: This pilot cross-sectional study on consecutive patients in University Hospital, Rheumatology Department, Clermont-Ferrand, France, was approved by the Ethics Committee (IRB number 2023-CF34). Pain was evaluated with the Numeric Pain Rating Scale (NPRS), Neuropathic Component of Chronic pain (NCCP) was screened with the DN4 questionnaire, and sleep was assessed with the Pittsburg questionnaire. Depression, anxiety, quality of life, and concomitant treatment were also evaluated. Results were expressed using effect sizes (ESs) and 95% confidence intervals. Results: Fifty new patients with a history of at least one fully documented fragility vertebral fracture (VF) or nonvertebral fracture (NVF) due to osteoporosis, in the last 2 years minus the previous 6 months, were included. Findings show that 21% patients with VF and 28% patients with NVF reported NCCP (DN ≥ 4). NCCP patients had more intense pain (NPRS = 5.1 ± 2.9 vs. 2.9 ± 2.7, ES = 0.82 [0.18; 1.44], p=0.019) and impaired sleep compared to patients without NCCP (ES = 0.71 [0.08; 1.33], p=0.043). A remarkable point was that patients had no specific oral or topical treatment for NCCP and were only taking on demand paracetamol and nonsteroidal anti-inflammatory drugs. Conclusions: Future research should focus on the neuropathic characteristics of pain patients with OP, in order to better manage OP-related pain.

Cross-Cultural Adaptation and Validation of the Central Sensitization Inventory Among Chinese Patients with Chronic Non-Specific Low Back Pain

Purpose

This research aims to develop and validate the Chinese version of the Central Sensitization Inventory (CSI-CV) for patients suffering from chronic non-specific low back pain (CNSLBP). The study evaluates both the validity and reliability of the CSI-CV.

Patients and Methods

The cross-cultural adaptation of the scale strictly adhered to the principles of Bombardier and Beaton. Initially, two professors of Chinese-English translation independently translated the original CSI scale into the target language, and then collaborated with an expert in cross-cultural adaptation to merge into a single version. This version was back-translated into English by two professors whose native language is English. Following this, the scale underwent preliminary review by bilingual experts and the research team, and was preliminarily tested, ultimately culminating in the formation of the CSI-CV version. A total of 310 patients with CNSLBP completed the CSI-CV, while 50 of them repeated the survey one week later to test the stability of the scale. The CSI-CV's reliability, validity, and internal consistency were assessed through exploratory factor analysis (EFA), correlation coefficients, and Cronbach's α.

Results

EFA revealed five distinct factors from the 25 CSI-CV items, covering physical symptoms, emotional distress, fatigue and sleep disturbances, headaches and jaw symptoms, and urinary issues, with a total explained variance of 60.24%. The Cronbach's α was 0.910, and the intraclass correlation coefficient (ICC) was 0.924, indicating strong reliability. Moderate correlations were observed between CSI-CV scores and Five-Level EuroQol Five-Dimensional Questionnaire (r = -0.515), the Brief Pain Inventory (r = 0.586) and Oswestry Disability Index (r = 0.416), demonstrating significant associations with these measures.

Conclusion

The CSI-CV exhibits excellent internal consistency, factor structure, and reliability. Its successful cultural adaptation offers valuable insights for improving treatment approaches for patients with CNSLBP.

Efficacy of Back Bracing in Treating Chronic Low Back Pain

Chronic low back pain (CLBP) negatively impacts quality of life and contributes to a significant economic burden. One conservative management strategy for CLBP is lumbar back bracing. Despite the benefits of back bracing for improving pain and function, there remains hesitance to use the therapy long term due to unfounded fear related to muscle weakness, deconditioning, or joint contracture.

OBJECTIVE

The purpose of this study was to examine the outcomes for patients with CLBP who were managed with lumbar back bracing and physical therapy.

METHODS

This was a single-site, retrospective chart review.

RESULTS

Patients were included in the study if they were treated for CLBP with back bracing for at least one hour daily and physical therapy for twelve weeks. Pain was assessed at three, six, and twelve months using the 11-point Visual Analogue Scale (VAS). Function was assessed at three months using the Oswestry Disability Index (ODI). The VAS score reduced from 6.28 +/- 2.32 to 3.96 +/- 2.66 at three months (p < 0.001) for 198 patients. At six and twelve months, the VAS score reduced to 3.74 +/- 2.73 (p < 0.001) and 3.23 +/- 2.29 (p < 0.001), respectively. The total ODI score for 199 patients improved from 46.56 +/- 15.30 to 33.13 +/- 19.99 (p < 0.001) at three months.

CONCLUSION

Back bracing in combination with physical therapy is effective for treating low back pain.

A Comparison of Pain Before and After Transfusion in Adult transfusion-dependent thalassemia (TDT) Using BPI-SF

Background Pain is a complication in patients with transfusion-dependent thalassemia (TDT). There are several mechanisms underlying pain in people with thalassemia and low hemoglobin at the end of the transfusion cycle was the most etiology. Pain can develop into chronic pain and interfere with the quality of life. The Brief Pain Inventory Short Form (BPI-SF) can help identify pain in people with TDT. The present study aimed to compare pain before and after transfusion in adult TDT patients. Methods It was an analytical observational study using a cross-sectional design on adult TDT patients with pain who came to the Haemato-Oncology Clinic of Dr. Hasan Sadikin Hospital Bandung. This study was conducted from December 2020 to July 2021. All subjects were assisted in filling out the Indonesian version of the BPI-SF questionnaire hemoglobin levels were examined and before and after transfusion, then paired test analysis was performed using the Wilcoxon Test. Results This study is conducted on 60 adult TDT patients with symptoms of pain. The median value of pain intensity and pain interferes with life obtained from the Indonesian version of the BPI-SF score after transfusion decreased significantly compared to before transfusion (NRS 5 vs. 0 and 2.8 vs. 0; p=0.0001). Conclusion There is a significant difference in pain intensity and pain interfere with life in adults with TDT before and after transfusion. It is necessary to carry out pain assessments for thalassemia patients.

Reduction of Chronic Primary Low Back Pain by Spinal Manipulative Therapy is Accompanied by Decreases in Segmental Mechanical Hyperalgesia and Pain Catastrophizing: A Randomized Placebo-controlled Dual-blind Mixed Experimental Trial

Chronic primary low back pain (CPLBP) refers to low back pain that persists over 3 months, that cannot be explained by another chronic condition, and that is associated with emotional distress and disability. Previous studies have shown that spinal manipulative therapy (SMT) is effective in relieving CPLBP, but the underlying mechanisms remain elusive. This randomized placebo-controlled dual-blind mixed experimental trial (NCT05162924) aimed to investigate the efficacy of SMT to improve CPLBP and its underlying mechanisms. Ninety-eight individuals with CPLBP and 49 controls were recruited. Individuals with CPLBP received SMT (n = 49) or a control intervention (n = 49), 12 times over 4 weeks. The primary outcomes were CPLBP intensity (0-100 on a numerical rating scale) and disability (Oswestry Disability Index). Secondary outcomes included pressure pain thresholds in 4 body regions, pain catastrophizing, Central Sensitization Inventory, depressive symptoms, and anxiety scores. Individuals with CPLBP showed widespread mechanical hyperalgesia (P < .001) and higher scores for all questionnaires (P < .001). SMT reduced pain intensity compared with the control intervention (mean difference: -11.7 [95% confidence interval, -11.0 to -12.5], P = .01), but not disability (P = .5). Similar mild to moderate adverse events were reported in both groups. Mechanical hyperalgesia at the manipulated segment was reduced after SMT compared with the control intervention (P < .05). Pain catastrophizing was reduced after SMT compared with the control intervention (P < .05), but this effect was not significant after accounting for changes in clinical pain. Although the reduction of segmental mechanical hyperalgesia likely contributes to the clinical benefits of SMT, the role of pain catastrophizing remains to be clarified. PERSPECTIVE: This randomized controlled trial found that 12 sessions of SMT yield greater relief of CPLBP than a control intervention. These clinical effects were independent of expectations, and accompanied by an attenuation of hyperalgesia in the targeted segment and a modulation of pain catastrophizing.

Low back pain classifications and their associations with disability, quality-of-life, and sociodemographic factors: a comprehensive examination using the PainDETECT questionnaire

BACKGROUND

Low back pain (LBP) is a debilitating phenomenon that significantly impacts quality-of-life (QoL). The PainDETECT questionnaire (PD-Q) is a screening tool aimed at distinguishing nociceptive pain (NoP) and neuropathic pain (NeP) classifications. Associations between these classifications and patient-reported outcome measures (PROMs) and sociodemographic parameters are yet to be established.

OBJECTIVE

The study aimed to determine the relationship between NeP as assessed by the PD-Q and pain, disability, QoL, and sociodemographic factors.

METHODS

A retrospective analysis of an ongoing prospectively collected database was conducted involving 512 patients aged >18 years who presented to a tertiary spine clinic for LBP having completed the PainDETECT questionnaire, Oswestry Disability Index (ODI), EuroQol Five-Dimensional (EQ-5D) questionnaire, or answered questions regarding sociodemographic status.

RESULTS

The NeP group had a higher mean numerical rating scale (NRS) score (7.96± 1.54 vs. 5.76± 2.27, p <.001) and lower age (55± 15.6 vs. 59± 17.8, p <.05) compared to the NoP group. When confounded for NRS, analysis of covariance demonstrated an 89.5% higher total ODI score (p <.001) and 50.5% lower EQ-5D utility score (p <.001) in the NeP compared to NoP group. Smokers and individuals with a no partner marital status were 2.373 (OR = 2.373, 95% CI = 1.319-4.266, p <.01) and 2.384 times (OR = 2.384, 95% CI = 1.390-4.092, p <.01) more likely to have NeP compared to NoP, respectively. Patients with NeP were also of lower income class compared to patients with NoP (Z = -2.45, p <.05).

CONCLUSION

NeP was associated with higher levels of disability and lower QoL. Smokers, individuals with a no partner marital status, and individuals with a lower income class were more likely to suffer NeP rather than NoP. These findings have illuminated a crucial notion: in patients with elevated NRS, the detrimental impact of NeP on patient wellbeing underscores the fundamental need to represent pain on a nociceptive-neuropathic continuum, permitting more accurate differentiation of pain components.

Pain intensity and opioid consumption after temporary and permanent peripheral nerve stimulation: a 2-year multicenter analysis

OBJECTIVE

Peripheral nerve stimulation (PNS) is an emerging neuromodulation modality, yet there remains limited data highlighting its long-term effectiveness. The objective of this study was to report real-world data on pain intensity and opioid consumption after temporary and permanent PNS for chronic pain up to 24 months postimplantation.

METHODS

A retrospective study was conducted on all patients who received PNS implants at a multi-centered enterprise between January 1, 2014 and February 24, 2022. The two co-primary outcomes were: (1) change in pain intensity (11-point Numerical Rating Scale) from baseline to 12 months postimplant; and (2) comparison of the change in pain intensity between temporary and permanent PNS cohorts 12 months postimplant.

RESULTS

126 patients were included in this analysis. Pain intensity significantly decreased 12 months postimplant in the overall cohort (mean difference (MD) -3.0 (95% CI -3.5 to -2.4), p<0.0001). No significant difference in this reduction was identified between temporary and permanent PNS cohorts (MD 0.0 (95% CI -1.1 to 1.0), p=1.00) 12 months postimplantation. Pain intensity significantly decreased in the overall, temporary, and permanent cohorts at all secondary time points (3, 6, and 24 months). No change in daily opioid consumption was observed at 6 and 12 months postimplant in the overall cohort.

CONCLUSION

This study found that both temporary and permanent PNS may be effective for reducing pain intensity in patients with chronic pain up to 24 months postimplantation, although no changes in opioid consumption were observed. The decrease in pain intensity was comparable between patients receiving temporary versus permanent implants, highlighting that temporary PNS may achieve long-lasting clinical benefits. However, given the substantial loss to follow-up, further large-scale studies are needed to solidify conclusions about the efficacy of PNS.

Cognitive behavioural interventions led by a physiotherapist in chronic non-specific low back pain: A systematic review and meta-analysis

BACKGROUND

The effectiveness of physiotherapist-led Cognitive Behavioural Interventions (CBI) with or without physiotherapy is still unclear.

OBJECTIVE

This systematic review (PROSPERO registration number CRD42022321073) aims to determine the effectiveness of physiotherapist-led CBI with or without physiotherapy in comparison to physiotherapy alone on quality of life, disabilities and catastrophization.

METHODS

MEDLINE, Web of Science, Science Direct, and PEDro were searched for randomized controlled trials that investigate the use of CBI versus conventional physiotherapy in chronic NSLBP. To be included CBI had to be performed by a physiotherapist. The primary and secondary outcomes were respectively quality of life and disability.

RESULTS

Fourteen studies were included in qualitative analysis, in which 4 did not meet the PEDro score of 6 or higher. Pooled standardized mean differences from 3 studies showed no difference in quality of life between groups for mental and physical sub-scores at 3 months (SMD 0.02, 95% CI -0.17 to 0.21 and SMD 0.07, 95% CI -0.12 to 0.26 respectively). Pooled standardized mean differences from 9 studies showed no difference in disability between groups at 3, 6 and 12 months (SMD = - 0.40, CI 95% -0.80 to 0.01; SMD -0.18, CI 95% = -0.41 to 0.05; and SMD -0.24, CI 95% = -0.48 to 0.00 respectively).

CONCLUSION

Results of CBI, especially cognitive functional therapy, seem promising in disability management despite a substantial heterogeneity. Furthermore, we found no difference in quality of life.

Comparative Neurological and Behavioral Assessment of Central and Peripheral Stimulation Technologies for Induced Pain and Cognitive Tasks

Pain is a multifaceted, multisystem disorder that adversely affects neuro-psychological processes. This study compares the effectiveness of central stimulation (transcranial direct current stimulation-tDCS over F3/F4) and peripheral stimulation (transcutaneous electrical nerve stimulation-TENS over the median nerve) in pain inhibition during a cognitive task in healthy volunteers and to observe potential neuro-cognitive improvements. Eighty healthy participants underwent a comprehensive experimental protocol, including cognitive assessments, the Cold Pressor Test (CPT) for pain induction, and tDCS/TENS administration. EEG recordings were conducted pre- and post-intervention across all conditions. The protocol for this study was categorized into four groups: G1 (control), G2 (TENS), G3 (anodal-tDCS), and G4 (cathodal-tDCS). Paired t-tests (p < 0.05) were conducted to compare Pre-Stage, Post-Stage, and neuromodulation conditions, with t-values providing insights into effect magnitudes. The result showed a reduction in pain intensity with TENS (p = 0.002, t-value = -5.34) and cathodal-tDCS (p = 0.023, t-value = -5.08) and increased pain tolerance with TENS (p = 0.009, t-value = 4.98) and cathodal-tDCS (p = 0.001, t-value = 5.78). Anodal-tDCS (p = 0.041, t-value = 4.86) improved cognitive performance. The EEG analysis revealed distinct neural oscillatory patterns across the groups. Specifically, G2 and G4 showed delta-power reductions, while G3 observed an increase. Moreover, G2 exhibited increased theta-power in the occipital region during CPT and Post-Stages. In the alpha-band, G2, G3, and G4 had reductions Post-Stage, while G1 and G3 increased. Additionally, beta-power increased in the frontal region for G2 and G3, contrasting with a reduction in G4. Furthermore, gamma-power globally increased during CPT1, with G1, G2, and G3 showing reductions Post-Stage, while G4 displayed a global decrease. The findings confirm the efficacy of TENS and tDCS as possible non-drug therapeutic alternatives for cognition with alleviation from pain.

Amyotrophic Lateral Sclerosis and Pain: A Narrative Review from Pain Assessment to Therapy

Amyotrophic lateral sclerosis (ALS) is the most frequent neurodegenerative disease of the motor system that affects upper and lower motor neurons, leading to progressive muscle weakness, spasticity, atrophy, and respiratory failure, with a life expectancy of 2-5 years after symptom onset. In addition to motor symptoms, patients with ALS have a multitude of nonmotor symptoms; in fact, it is currently considered a multisystem disease. The purpose of our narrative review is to evaluate the different types of pain, the correlation between pain and the disease's stages, the pain assessment tools in ALS patients, and the available therapies focusing above all on the benefits of cannabis use. Pain is an underestimated and undertreated symptom that, in the last few years, has received more attention from research because it has a strong impact on the quality of life of these patients. The prevalence of pain is between 15% and 85% of ALS patients, and the studies on the type and intensity of pain are controversial. The absence of pain assessment tools validated in the ALS population and the dissimilar study designs influence the knowledge of ALS pain and consequently the pharmacological therapy. Several studies suggest that ALS is associated with changes in the endocannabinoid system, and the use of cannabis could slow the disease progression due to its neuroprotective action and act on pain, spasticity, cramps, sialorrhea, and depression. Our research has shown high patients' satisfaction with the use of cannabis for the treatment of spasticity and related pain. However, especially due to the ethical problems and the lack of interest of pharmaceutical companies, further studies are needed to ensure the most appropriate care for ALS patients.

Testing Biological and Psychological Pathways of Emotion Regulation as a Primary Mechanism of Action in Yoga Interventions for Chronic Low Back Pain: Protocol for a Randomized Controlled Trial

BACKGROUND

Interventions that promote adaptive emotion regulation (ER) skills reduce pain in patients with chronic pain; however, whether the effects of yoga practice on chronic low back pain (CLBP) are due to improvements in ER remains to be examined.

OBJECTIVE

This study will test whether the effects of yoga on CLBP (improved pain severity and interference) are mediated by improved ER, the extent to which effects are related to specific aspects of ER, and the role of pain sensitization as a mediator or moderator of effects. In this study, pain sensitization will be assessed by quantitative sensory testing and gene expression profiles to examine whether pain sensitization moderates yoga's effects on pain or whether yoga and ER abilities reduce pain sensitization, leading to decreased pain severity and interference.

METHODS

For this 2-arm parallel group blinded randomized controlled trial, we will enroll 204 adults with CLBP who will be randomized to receive the yoga (n=102) or a control stretching and strengthening (n=102) intervention, which are delivered via web-based synchronous biweekly 75-minute sessions over 12 weeks. Participants are encouraged to practice postures or exercises for 25 minutes on other days using accessible prerecorded practice videos that are sent to participants digitally. Participants will be assessed at 5 time points: baseline, midintervention (6 weeks), postintervention (12 weeks), and 3- and 6-month follow-ups. Assessments of ER, pain severity and interference, pain sensitivity including somatosensory and gene expression profiles, and physical strength and flexibility will be conducted at each visit. The fidelity of the interventions is assessed using a manualized checklist to evaluate recorded group sessions to ensure consistent instructor delivery.

RESULTS

The primary outcome will be the mean change in pain severity as measured by the Brief Pain Inventory-Short Form at 12 weeks. The primary mechanism of action is ER measured by change in the Difficulties in Emotion Regulation Scale total score. Secondary outcomes include pain sensitivity, physical strength and flexibility, pain interference, and quality of life. A mediation path analysis and series of moderated mediation path analyses will be conducted to test the study hypotheses. As of January 2024, we have enrolled 138 participants. We expect the study to be completed by May 2025.

CONCLUSIONS

The study will provide important data for evaluating whether improvements in ER are responsible for reduced pain perception and pain sensitivity as well as increased quality of life in the context of chronic pain. The study findings have important implications for determining the mechanism of action for yoga and possibly other mind-body interventions as nonpharmacological therapies for pain management. The results of the study will inform the content, delivery, and measures for intervention trials involving yoga as a modality for relieving pain and improving function.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04678297; https://clinicaltrials.gov/study/NCT04678297.

INTERNATIONAL REGISTERED REPORT IDENTIFIER (IRRID)

DERR1-10.2196/56016.

Preemptive administration of mesenchymal stem cells-derived conditioned medium can attenuate the development of neuropathic pain in rats via downregulation of proinflammatory cytokines

Neuropathic pain (NP) is a chronic condition characterized by persistent pain following nerve injury. It is a challenging clinical problem to manage due to limited treatment options. Mesenchymal stem cells (MSCs)-derived conditioned medium (CM) is a cell-free product that contains the secretome of MSCs and has been shown to have therapeutic potential in various inflammatory and degenerative disorders. Several animal studies have examined the antinociceptive effects of MSCs-CM on established neuropathic pain, but none have investigated the early prevention of neuropathic pain using MSCs-CM. Therefore, in this study, we tested whether preemptive administration of MSCs-CM could attenuate the development of NP in rats. To this end, NP was induced in Wistar rats using a chronic constriction injury (CCI) model (day 0), and then the animals were divided into four groups: Sham, CCI, CCI-Dulbecco's Modified Eagle Medium (DMEM), and CCI-CM. The CCI-CM group received 1 ml intraperitoneal administration of MSCs-CM on days - 1, 1, and 2, while the Sham, CCI, and CCI-DMEM groups received vehicle only (normal saline or DMEM). Mechanical withdrawal threshold and thermal withdrawal latency were assessed to evaluate pain sensitivities. In addition, the expression levels of proinflammatory cytokines (TNF-α and IL-1β) in the spinal cord tissues were measured using quantitative real-time PCR (qRT-PCR). The results demonstrated that preemptive treatment with MSCs-CM can significantly attenuate the development of NP, as evidenced by improved mechanical withdrawal threshold and thermal withdrawal latency in the CCI-CM group compared to the CCI and CCI-DMEM groups. Furthermore, the relative gene expression of proinflammatory cytokines TNF-α and IL-1β were significantly decreased in the spinal cord tissues of the CCI-CM group compared to the control groups. These findings suggest that preemptive administration of MSCs-CM can attenuate the development of NP in rats, partly due to the downregulation of proinflammatory cytokines.

Application of a Clinical Approach to Diagnosing Primary Pain: Prevalence and Correlates of Primary Back and Neck Pain in a Community Physiatry Clinic

Chronic back or neck pain (CBNP) can be primary (nociplastic or neuroplastic; without clear peripheral etiology) or secondary (to nociceptive or neuropathic causes). Expanding on available models of nociplastic pain, we developed a clinic-ready approach to diagnose primary/nociplastic pain: first, a standard physical exam and review of imaging to rule out secondary pain; and second, a detailed history of symptom presentation to rule in primary pain. We trained a physician who evaluated 222 patients (73.9% female, age M = 59.6) with CBNP; patients separately completed pain and psychosocial questionnaires. We estimated the prevalence of primary CBNP and explored biomedical, imaging, and psychological correlates of primary CBNP. Although almost all patients (97.7%) had at least 1 spinal anomaly on imaging, the diagnostic approach estimated that 88.3% of patients had primary pain, 5.0% had secondary pain, and 6.8% had mixed pain. Patients with primary pain were more likely than the other 2 groups of patients (combined as "non-primary pain") to report certain functional conditions, central sensitization, and features such as sensitivity to light touch, spreading pain, and pain worsening with stress; however, no difference was detected in depression, anxiety, and pain catastrophizing between those with primary and nonprimary pain. These findings are consistent with prior estimates that 85 to 90% of CBNP is "nonspecific." Further research is needed to validate and perhaps refine this diagnostic approach, which holds the potential for better outcomes if patients are offered treatments targeted to primary pain, such as pain neuroscience education and several emerging psychological therapies. PERSPECTIVE: We developed an approach to diagnose chronic primary pain, which was applied in a physiatry clinic to 222 patients with CBNP. Most patients (88.3%) had primary pain, despite almost universal anomalies on spinal imaging. This diagnostic approach can guide educational and psychological treatments tailored for primary pain.

Myofascial pain - A major player in musculoskeletal pain

Myofascial pain is a soft tissue pain syndrome with local and referred musculoskeletal pain arising from trigger points. Myofascial pain and myofascial pain syndromes are among some of the most common acute and chronic pain conditions. Myofascial pain can exist independently of other pain generators or can coexist with or is secondary to other acute and chronic painful musculoskeletal conditions. Myofascial pain is most effectively treated with a multimodal treatment plan including injection therapy (known as trigger point injections, physical therapy, postural or ergonomic correction, and treatment of underlying musculoskeletal pain generators. The objectives of this review are to outline the prevalence of myofascial pain, describe the known pathophysiology of myofascial pain and trigger points, discuss the clinical presentation of myofascial pain, and present evidence-based best practices for pharmacologic, non-pharmacologic, and interventional treatments for myofascial pain.

Nociceptive, neuropathic, or nociplastic low back pain? The low back pain phenotyping (BACPAP) consortium's international and multidisciplinary consensus recommendations

The potential to classify low back pain as being characterised by dominant nociceptive, neuropathic, or nociplastic mechanisms is a clinically relevant issue. Preliminary evidence suggests that these low back pain phenotypes might respond differently to treatments; however, more research must be done before making specific recommendations. Accordingly, the low back pain phenotyping (BACPAP) consortium was established as a group of 36 clinicians and researchers from 13 countries (five continents) and 29 institutions, to apply a modified Nominal Group Technique methodology to develop international and multidisciplinary consensus recommendations to provide guidance for identifying the dominant pain phenotype in patients with low back pain, and potentially adapt pain management strategies. The BACPAP consortium's recommendations are also intended to provide direction for future clinical research by building on the established clinical criteria for neuropathic and nociplastic pain. The BACPAP consortium's consensus recommendations are a necessary early step in the process to determine if personalised pain medicine based on pain phenotypes is feasible for low back pain management. Therefore, these recommendations are not ready to be implemented in clinical practice until additional evidence is generated that is specific to these low back pain phenotypes.

Developing an initial set of quality indicators for chiropractic care: a scoping review

BACKGROUND

Quality indicators are standardized, evidence-based measures of health care quality. Currently, there is no basic set of quality indicators for chiropractic care published in peer-reviewed literature. The goal of this research is to develop a preliminary set of quality indicators, measurable with administrative data.

METHODS

We conducted a scoping review searching PubMed/MEDLINE, CINAHL, and Index to Chiropractic Literature databases. Eligible articles were published after 2011, in English, developing/reporting best practices and clinical guidelines specifically developed for, or directly applicable to, chiropractic care. Eligible non-peer-reviewed sources such as quality measures published by the Centers for Medicare and Medicaid Services and the Royal College of Chiropractors quality standards were also included. Following a stepwise eligibility determination process, data abstraction identified specific statements from included sources that can conceivably be measured with administrative data. Once identified, statements were transformed into potential indicators by: 1) Generating a brief title and description; 2) Documenting a source; 3) Developing a metric; and 4) Assigning a Donabedian category (structure, process, outcome). Draft indicators then traversed a 5-step assessment: 1) Describes a narrowly defined structure, process, or outcome; 2) Quantitative data can conceivably be available; 3) Performance is achievable; 4) Metric is relevant; 5) Data are obtainable within reasonable time limits. Indicators meeting all criteria were included in the final set.

RESULTS

Literature searching revealed 2562 articles. After removing duplicates and conducting eligibility determination, 18 remained. Most were clinical guidelines (n = 10) and best practice recommendations (n = 6), with 1 consensus and 1 clinical standards development study. Data abstraction and transformation produced 204 draft quality indicators. Of those, 57 did not meet 1 or more assessment criteria. After removing duplicates, 70 distinct indicators remained. Most indicators matched the Donabedian category of process (n = 35), with 31 structure and 4 outcome indicators. No sources were identified to support indicator development from patient perspectives.

CONCLUSIONS

This article proposes a preliminary set of 70 quality indicators for chiropractic care, theoretically measurable with administrative data and largely obtained from electronic health records. Future research should assess feasibility, achieve stakeholder consensus, develop additional indicators including those considering patient perspectives, and study relationships with clinical outcomes.

TRIAL REGISTRATION

Open Science Framework, https://osf.io/t7kgm.

Central Sensitization in Patients with Chronic Pain Secondary to Carpal Tunnel Syndrome and Determinants

Purpose

Central sensitization (CS) is commonly seen in chronic pain disorders, including neuropathic pain. However, there exist inconsistencies concerning the presence of CS in chronic pain secondary to carpal tunnel syndrome (CTS). CS and neuropathic pain manifestations in CTS remain not well established. Therefore, this study aims to investigate the CS and pain profiles in patients with CTS and to explore the potential determinants associated with CS.

Patients and Methods

Patients with suspected CTS symptoms lasting 3 months or above and healthy controls were enrolled. History, physical examinations, and nerve conduction studies were employed to confirm the diagnosis and severity of median nerve dysfunction. The central sensitization inventory (CSI) was used to screen CS. Other outcomes included neuropathic pain, CTS-specific symptom severity and functions, emotion, and health-related quality of life. Between-group comparisons were conducted in terms of the CS presence. Logistic regression analysis was performed to identify determinants associated with CS.

Results

Over 60% of participants with CTS were found with clinical CS, significantly higher than that in the control group. More than 70% of the CTS participants were identified to have possible or very likely neuropathic pain components. In addition, one-fourth of CTS cases had depression or anxiety. Anxiety was associated with an increased risk of developing CS in CTS (adjusted OR=1.31, 95% CI 1.08-1.59), whereas higher self-perceived general health rating was negatively associated with the presence of CS (adjusted OR=0.92, 95% CI 0.88-0.97) in the multivariate adjusted regression model.

Conclusion

CS is prevalent in patients with CTS. Predominant neuropathic pain characteristics were uncovered in CTS patients as well as comorbid psychological distress. Significant association was found between anxiety and CS presence. Self-perceived general health was inversely related to CS. Further research is warranted to explore the mechanisms of anxiety and central pain processing in painful entrapment neuropathy.

Neural correlates of central pain sensitization in chronic low back pain: a resting-state fMRI study

PURPOSE

The objective of this study is to explore the neural correlates of pain sensitization in patients with chronic low back pain (cLBP). While the association between cLBP and pain sensitization has been widely reported, the underlying brain mechanism responsible for this relationship requires further investigation.

METHODS

Our study included 56 cLBP patients and 56 healthy controls (HC). Functional magnetic resonance imaging data were obtained, and the voxel-wise amplitude of low-frequency fluctuation (ALFF) was calculated to identify brain alterations in cLBP patients compared to HC groups. Pearson correlation coefficients were computed to explore the association between clinical data and brain alterations. Furthermore, mediation analyses were performed to investigate the path association between brain alterations and pain-related behaviors.

RESULTS

Our findings revealed that patients with cLBP exhibited higher sensitivity, attention, and catastrophizing tendencies towards pain compared to HC. Furthermore, cLBP patients displayed significantly higher ALFF in various brain regions within the "pain matrix" and the default mode network when compared to HC. The altered precuneus ALFF was positively correlated with pain intensity (R = 0.51, P<0.001) and was negatively correlated with pain sensitivity (R = -0.43, P<0.001) in cLBP patients. Importantly, the effect of altered precuneus ALFF on pain intensity was mediated by pain threshold in these patients.

CONCLUSION

Our study suggests that altered neural activity in the precuneus may contribute to pain hypersensitivity, which further exacerbating pain in cLBP patients.

Simplified functioning assessment for low back pain: ICF-based item response theory modelling

BACKGROUND

Despite the growing interest of the item response theory (IRT) in assessment of person abilities and functioning difficulties in screening tools, there is scarcity of research using IRT on ICF-based tools for persons with low back pain (LBP).

AIM

To generate and validate a parsimonious core set of ICF (PCSI) for LBP based on the IRT modelling.

DESIGN

A cross-sectional study.

SETTING

Nine hospitals in Jiangsu Province, China.

POPULATION

We recruited patients with LBP.

METHODS

All participants completed the 78 items of the comprehensive ICF Core Set for LBP. The five-point scoring system was converted to dichotomous data with 1 as functioning/independent and 0 as impairment/dependent. Psychometric properties of the data were examined using Mokken Scale analysis and parametric item response modelling.

RESULTS

This study recruited 306 participants (185 females and 121 males) with LBP. The overall median age of the study participants was 50.28 (95% CI 23.34; 82.05) years. We constructed a three-parameter logistic model with 28 ICF categories (8 of body function, 18 of activities and participation, and two of body structures). The internal consistency was good with Cronbach's alpha = 0.927 and latent class reliability coefficient (LCRC) = 0.955. The model was validated by significant correlations (P<0.001) of its estimated person abilities with the Oswestry Disability Index (ODI, r=-0.41), the Roland-Morris Disability Questionnaire (RMDQ, r=-0.57), the Physical Component Summary (PCS, r=0.63), and the Mental Component Summary (MCS, r = 0.46) of 12-Item Short Form Survey (SF-12). The person abilities and item difficulties were integrated into a Wright map that offered a background for making individualized clinical decisions.

CONCLUSIONS

The PCSI of LBP with 28 categories has good construct validity and internal consistency, and is a convenient instrument for assessing functioning among persons with LBP. The IRT model provided theoretical and algorithmic support for deriving a simplified model for functioning assessment hence serving a basis for formulating rehabilitation plans in clinical practice and research.

CLINICAL REHABILITATION IMPACT

A parsimonious core set of ICF (PCSI) for LBP based on the IRT modelling provides a background for making individualized clinical decisions based on item difficulties.

Efficacy of conditioned autologous serum therapy (Orthokine®) on the dorsal root ganglion in patients with chronic radiculalgia: study protocol for a prospective randomized placebo-controlled double-blind clinical trial (RADISAC trial)

BACKGROUND

Pulsed radiofrequency (PRF) treatment on the dorsal root ganglion (DRG) has been proposed as a good option for the treatment of persistent radicular pain based on its effect of neuromodulation on neuropathic pain. Autologous conditioned serum (ACS) therapy is a conservative treatment based on the patient's own blood. The aim of this manuscript is to develop a study protocol using ACS on the DRG as a target for its molecular modulation.

METHODS

We plan to conduct a randomized controlled study to compare the efficacy of PRF therapy plus ACS versus PRF therapy plus physiological saline 0.9% (PhS) on the DRG to reduce neuropathic pain in patients with persistent lower limb radiculalgia (LLR) and to contribute to the functional improvement and quality of life of these patients. Study participants will include patients who meet study the inclusion/exclusion criteria. Eligible patients will be randomized in a 1:1 ratio to one of treatment with PRF plus ACS (experimental group) or PRF plus PhS (placebo group). The study group will consist of 70 patients (35 per group) who have experienced radicular pain symptoms for ≥ 6 months' duration who have failed to respond to any therapy. Both groups will receive PRF on the DRG treatment before the injection of the sample (control or placebo). Patient assessments will occur at baseline, 1 month, 3 months, 6 months, and 12 months after therapy. The primary efficacy outcome measure is Numeric Pain Rating Scale (NPRS) responders from baseline to 12 months of follow-up using validated minimal important change (MIC) thresholds. A reduction of ≥ 2 points in NPRS is considered a clinically significant pain relief. The secondary efficacy outcome measure is the proportion of Oswestry Low Back Pain Disability Scale (ODS) responders from baseline to 12 months of follow-up in the experimental group (PRF plus ACS) versus the placebo group (PRF plus PhS). ODS responders are defined as those patients achieving the validated MIC of ≥ 10-point improvement in ODS from baseline to 12 months of follow-up as a clinically significant efficacy threshold.

DISCUSSION

This prospective, double-blind, randomized placebo-controlled study will provide level I evidence of the safety and effectiveness of ACS on neuropathic symptoms in LLR patients. TRIAL REGISTRATION {2A}{2B}: EUDRACT number: 2021-005124-38. Validation date: 13 November 2021. Protocol version {3}: This manuscript presents the 2nd protocol version.

Association of central sensitization, visceral fat, and surgical outcomes in lumbar spinal stenosis

BACKGROUND

Controversy remains regarding predictors of surgical outcomes for patients with lumbar spinal stenosis (LSS). Pain sensitization may be an underlying mechanism contributing to LSS surgical outcomes. Further, obesity is associated with dissatisfaction and poorer outcomes after surgery for LSS. Therefore, this study aimed to examine the relationship between central sensitization (CS), visceral fat, and surgical outcomes in LSS.

METHODS

Patients with LSS were categorized based on their central sensitization inventory (CSI) scores into low- (CSI < 40) and high- (CSI ≥ 40) CSI subgroups. The participants completed clinical outcome assessments preoperatively and 12 months postoperatively.

RESULTS

Overall, 60 patients were enrolled in the study (28 men, 32 women; mean age: 62.1 ± 2.8 years). The high-CSI group had significantly higher mean low back pain (LBP), leg pain, and leg numbness visual analogue scale (VAS) scores than the low-CSI group (p < 0.01). The high-CSI group had a significantly higher mean visceral fat area than the low-CSI group (p < 0.01). Postoperatively, LBP VAS score was significantly worse in the high-CSI group. Relative to preoperatively, postoperative leg pain and leg numbness improved significantly in both groups.

CONCLUSIONS

We believe that neuro decompression can be effective for LSS surgical outcomes in patients with CS; nonetheless, it should be approached with caution owing to the potential for worsening LBP. Additionally, visceral fat is an important indicator suggesting the involvement of CS.

Antinociceptive effect of Nephelium lappaceum L. fruit peel and the participation of nitric oxide, opioid receptors, and ATP-sensitive potassium channels

Introduction: Nephelium lappaceum L. (Sapindaceae) is a plant known as rambutan. It is used for various purposes in traditional medicine. Objective: We aimed to evaluate the antinociceptive effects of the ethanol extract of the fruit peel of N. lappaceum (EENL), the mechanisms involved in these effects, and the acute toxicity in zebrafish. Methods: We performed chromatography coupled to mass spectrometry, acute toxicity assay in zebrafish, and evaluation in mice submitted to models of nociception and locomotor activity. Results: We identified (epi)-catechin, procyanidin B, and ellagic acid and its derivatives in EENL. We did not find any toxicity in zebrafish embryos incubated with EENL. The locomotor activity of mice submitted to oral pretreatment with EENL was not changed, but it reduced the abdominal constrictions induced by acetic acid, the licking/biting time in both the first and second phase of formalin testing and capsaicin testing, and carrageenan-induced paw mechanical allodynia. Oral pretreatment with EENL increased latency time in the hot plate test. This antinociceptive effect was significantly reversed by naloxone, L-arginine, and glibenclamide respectively showing the participation of opioid receptors, nitric oxide, and KATP channels as mediators of EENL-induced antinociception. Conclusion: EENL causes antinociception with the participation of opioid receptors, nitric oxide, and KATP channels, and is not toxic to zebrafish.

Listening to Remotely Monitored Home-based Preferred Music for Pain in Older Black Adults with Low Back Pain: A Pilot Study of Feasibility and Acceptability

BACKGROUND

Low back pain (LBP) is a complex condition that is widespread among older Black adults. Nonpharmacologic interventions are recommended as first-line therapy, but their use in practice is limited, possibly due to misunderstanding of their analgesic characteristics.

AIM

To determine the feasibility and acceptability of listening to preferred music at home to relieve pain in older Black adults aged 65 years or older with LBP.

METHOD

We recruited 20 community-dwelling older adults (≥65 years) with LBP to use noise-isolating headphones to listen to their preferred music for 20 minutes twice daily for four days via the MUSIC CARE® app. Feasibility was determined using enrollment, adherence, and attrition rates, and acceptability was determined using the Treatment Acceptance and Preference (TAP) scale. Average pain scores were self-reported using the Numeric Rating Scale (NRS) after the second intervention of the day. Pain scores were evaluated using paired sample t test and repeated-measures ANOVA.

RESULTS

Enrollment, adherence, and attrition rates were 95.25%, 100.00%, and 0.00%, respectively. Most participants rated the TAP scale at ≥3, indicating acceptance. Pain scores decreased significantly from baseline (M = 46.90, SD = 21.47) to post-intervention (M = 35.70, SD = 16.57), t (19) = 2.29, p = .03. Repeated measures ANOVA showed a significant decrease in mean pain scores over time [F (2.36, 44.88) = 5.61, p = .004, η2 = .23].

CONCLUSIONS

Listening to preferred music for 20 minutes twice a day is a feasible and acceptable intervention that can considerably reduce pain in older Black adults with LBP.

Identifying chronic low back pain phenotypic domains and characteristics accounting for individual variation: a systematic review

ABSTRACT

Interpatient variability is frequently observed among individuals with chronic low back pain (cLBP). This review aimed at identifying phenotypic domains and characteristics that account for interpatient variability in cLBP. We searched MEDLINE ALL (through Ovid), Embase Classic and EMBASE (through Ovid), Scopus, and CINAHL Complete (through EBSCOhost) databases. Studies that aimed to identify or predict cLBP different phenotypes were included. We excluded studies that focused on specific treatments. The methodological quality was assessed using an adaptation of the Downs and Black tool. Forty-three studies were included. Although the patient and pain-related characteristics used to identify phenotypes varied considerably across studies, the following were among the most identified phenotypic domains and characteristics that account for interpatient variability in cLBP: pain-related characteristics (including location, severity, qualities, and duration) and pain impact (including disability, sleep, and fatigue), psychological domains (including anxiety and depression), behavioral domains (including coping, somatization, fear avoidance, and catastrophizing), social domains (including employment and social support), and sensory profiling (including pain sensitivity and sensitization). Despite these findings, our review showed that the evidence on pain phenotyping still requires further investigation. The assessment of the methodological quality revealed several limitations. We recommend adopting a standard methodology to enhance the generalizability of the results and the implementation of a comprehensive and feasible assessment framework to facilitate personalized treatments in clinical settings.

Towards data-driven biopsychosocial classification of non-specific chronic low back pain: a pilot study

The classification of non-specific chronic low back pain (CLBP) according to multidimensional data could guide clinical management; yet recent systematic reviews show this has not been attempted. This was a prospective cross-sectional study of participants with CLBP (n = 21) and age-, sex- and height-matched pain-free controls (n = 21). Nervous system, lumbar spinal tissue and psychosocial factors were collected. Dimensionality reduction was followed by fuzzy c-means clustering to determine sub-groups. Machine learning models (Support Vector Machine, k-Nearest Neighbour, Naïve Bayes and Random Forest) were used to determine the accuracy of classification to sub-groups. The primary analysis showed that four factors (cognitive function, depressive symptoms, general self-efficacy and anxiety symptoms) and two clusters (normal versus impaired psychosocial profiles) optimally classified participants. The error rates in classification models ranged from 4.2 to 14.2% when only CLBP patients were considered and increased to 24.2 to 37.5% when pain-free controls were added. This data-driven pilot study classified participants with CLBP into sub-groups, primarily based on psychosocial factors. This contributes to the literature as it was the first study to evaluate data-driven machine learning CLBP classification based on nervous system, lumbar spinal tissue and psychosocial factors. Future studies with larger sample sizes should validate these findings.

Urinary TNF-α as a potential biomarker for chronic primary low back pain

Introduction

Over two thirds of individuals with low back pain (LBP) may experience recurrent or persistent symptoms in the long term. Yet, current data do not allow to predict who will develop chronic low back pain and who will recover from an acute episode. Elevated serum levels of the proinflammatory cytokine tumor necrosis factor-α (TNF-α) have been associated with poor recovery and persistent pain following an acute episode of LBP. Inflammatory cytokines may also mediate mechanisms involved in nociplastic pain, and thus, have significant implications in chronic primary low back pain (CPLBP).

Methods

This study aimed to investigate the potential of urinary TNF-α levels for predicting outcomes and characterizing clinical features of CPLBP patients. Twenty-four patients with CPLBP and 24 sex- and age-matched asymptomatic controls were recruited. Urinary TNF-α concentrations were measured at baseline and after 4 weeks, during which CPLBP patients underwent spinal manipulative therapy (SMT).

Results

Concentrations of TNF-α were found to be elevated in baseline urine samples of CPLBP patients compared to asymptomatic controls. Moreover, these values differed among patients depending on their pain trajectory. Patients with persistent pain showed higher levels of TNF-α, when compared to those with episodic CPLBP. Furthermore, baseline TNF-α concentrations and their changes after 4 weeks predicted alterations in pain intensity and disability following SMT in patients with CPLBP.

Discussion

These findings warrant further research on the potential use of urinary TNF-α concentrations as a prognostic biomarker for CPLBP.

Consideration of Psychosocial Factors in Acute Low Back Pain by Physical Therapists

Clinical guidelines consistently recommend screening psychosocial (PS) factors in patients with low back pain (LBP), regardless of its mechanical nature, as recognized contributors to pain chronicity. However, the ability of physiotherapists (PTs) in identifying these factors remains controversial. This study aimed to assess the current identification of psychosocial risk factors by physical therapists (PTs) and which characteristics of PTs are associated with the identification of the main risk for chronicity (physical or psychosocial). A cross-sectional descriptive study surveying Spanish PTs in public and private health services was conducted, including questions on PT characteristics and three low back pain (LBP) patient vignettes with different biopsychosocial (BPS) clinical presentations. From 484 respondents, the majority of PTs agreed regarding the main risk for chronicity for each vignette (PS 95.7% for vignette A, PS and physical 83.5% for vignette B and PS 66% for vignette C). Female PTs were more likely to rate psychosocial compared with males (p < 0.05). PTs with higher levels of social and emotional intelligence (both, p < 0.05) were more likely to identify the main risk for chronicity. However, only gender and social information processing for vignette A (p = 0.024) and emotional clarity for vignette B (p = 0.006) were able to predict the identification of psychosocial and physical risk, respectively. The main risk for chronicity was correctly identified by a large majority of PTs through patient vignettes. Gender, social and emotional intelligence played a relevant role in the recognition of psychosocial risk and biopsychosocial factors.

Pressure Pain Threshold Protocols With Pressure Algometer in Patients With Low Back Pain: A Systematic Review With Meta-Analysis

OBJECTIVE

The pressure pain threshold is commonly employed to assess pain in various conditions. Despite its widespread use, the measurement of pressure pain thresholds is not consistently described across studies. Therefore, this review aimed to systematically examine the evidence regarding the assessment of pressure pain thresholds in patients with low back pain, including the protocols and body sites employed.

METHODS

Six databases were systematically screened from their earliest records to May 2023 to identify studies utilizing pressure pain thresholds. Eligibility screening was conducted for the identified studies, and the included studies underwent appraisal using the appropriate tool corresponding to their study design.

RESULTS

Upon categorizing based on the type of pain, we included 5 studies involving acute low back pain and 43 studies with chronic pain. The meta-analysis was conducted to compare subjects with and without pain, revealing no significant difference for the paraspinal region (SMD = -4.19, 95%CI = -11.7 to 3.32, z = -1.09, p = .27), piriformis (SMD = -1.24, 95%CI = -4.25 to 1.76, z = -0.81, p = .42) and quadratus lumborum musculature (SMD = -0.37, 95%CI = -1.35 to 0.60, z = -0.75, p = .45).

CONCLUSION

The paraspinal and gluteal musculature are the most frequently evaluated. Concerning the protocols for assessment, no consensus was identified. However, studies that assessed chronic low back pain typically adhered to a similar approach regarding the number of measures and a constant increase in pressure.

Between guidelines and clinical trials: evidence-based advice on the pharmacological management of non-specific chronic low back pain

The pharmacological management of nonspecific chronic low back pain (NCLBP) aims to restore patients' daily activities and improve their quality of life. The management of NCLBP is not well codified and extremely heterogeneous, and residual symptoms are common. Pharmacological management should be considered as co-adjuvant to non-pharmacological therapy, and should be guided by the symptoms reported by the patients. Depending on the individual severity of NCLPB, pharmacological management may range from nonopioid to opioid analgesics. It is important to identify patients with generalized sensory hypersensitivity, who may benefit from dedicated therapy. This article provides an evidence-based overview of the principles of pharmacological management of NCLPB.

The effect of skilled motor training on corticomotor control of back muscles in different presentations of low back pain

Transcranial magnetic stimulation (TMS) has revealed differences in the motor cortex (M1) between people with and without low back pain (LBP). There is potential to reverse these changes using motor skill training, but it remains unclear whether changes can be induced in people with LBP or whether this differs between LBP presentations. This study (1) compared TMS measures of M1 (single and paired-pulse) and performance of a motor task (lumbopelvic tilting) between individuals with LBP of predominant nociceptive (n = 9) or nociplastic presentation (n = 9) and pain-free individuals (n = 16); (2) compared these measures pre- and post-training; and (3) explored correlations between TMS measures, motor performance, and clinical features. TMS measures did not differ between groups at baseline. The nociplastic group undershot the target in the motor task. Despite improved motor performance for all groups, only MEP amplitudes increased across the recruitment curve and only for the pain-free and nociplastic groups. TMS measures did not correlate with motor performance or clinical features. Some elements of motor task performance and changes in corticomotor excitability differed between LBP groups. Absence of changes in intra-cortical TMS measures suggests regions other than M1 are likely to be involved in skill learning of back muscles.

Microbiological and Physiological Effects of Pain

Pain is an important innate defense mechanism that can dramatically alter a person's quality of life. Understanding the microbiological and physiological effects of pain may be important in the pursuit of novel pain interventions. The three descriptors of pain recognized by the International Association for the Study of Pain are nociceptive, neuropathic, and nociplastic pain. Our review examined the current understanding of all three pain types, focusing on the key molecules involved in the manifestation of each type as well as physiological effects. Additionally, we compared the differences in painful and painless neuropathies and discussed the neuroimmune interaction involved in the manifestation of pain.

Ultrasound Imaging of Thoracolumbar Fascia Thickness: Chronic Non-Specific Lower Back Pain versus Healthy Subjects; A Sign of a "Frozen Back"?

The thoracolumbar fascia (TLF) plays an important role in lower back pain (LBP). Recent studies have revealed an association between increases in TLF thickness and reduced TLF gliding in patients with LBP. The purpose of this study was to measure and compare by ultrasound (US) imaging the thickness of the TLF at the bilateral L3 level of the lumbar spine in the longitudinal and transverse axes in chronic non-specific LBP and in healthy subjects. A cross-sectional study was performed using US imaging to measure the longitudinal and transverse axes with a new protocol in a sample of 92 subjects: 46 chronic non-specific LBP patients and 46 healthy participants. The findings for TLF thickness revealed statistically significant differences (p < 0.05) in the longitudinal and transverse axes between the two groups. Moreover, in the healthy group, a statistically significant difference was found between the longitudinal and transverse axes (p = 0.001 for left and p = 0.02 for right), which was not evident in the LBP patients. These findings suggest that the LBP patients lost anisotropy of the TLF, with it becoming homogeneously thicker and losing adaptability in the transversal direction. The US imaging evaluation suggests that TLF thickness behavior points out altered fascial remodelling compared to healthy subjects, a sort of "frozen back".

Patient-reported outcome measurements (PROMs): Use during the physical therapy practice and associated factors

OBJECTIVE

To assess the current level of routine use of psychosocial-related patient-reported outcome measurements (PROMs) in physical therapy practice and which physical therapist-level factors are associated with the use of these measurement instruments.

METHODS

We conducted an online survey study among Spanish physical therapists involved in the treatment of LBP patients in Public Health Service, Mutual Insurance Companies, and private practice during 2020. Descriptive analyses were conducted for reporting the number and instruments utilized. Thus, sociodemographic and professional features differences between PTs using and not using PROM were analyzed.

RESULTS

From 485 physiotherapists completing the questionnaire nationwide, 484 were included. A minority of therapists routinely used psychosocial-related PROMs (13.8%) in LBP patients and only 6.8% did so through standardized measurements instruments. The Tampa Scale for Kinesiophobia (28.8%) and the Pain Catastrophizing Scale (15.1%) were used most frequently. Physiotherapists working in Andalucía and País Vasco regions, in private practice environments, educated in psychosocial factors evaluation and management, considering psychosocial factors during the clinical practice and expecting patients' collaborative attitudes demonstrated significantly greater use of PROMS (p < 0.05).

CONCLUSIONS

This study showed that the majority of physiotherapists in Spain do not use PROMs for evaluating LBP (86.2%). From those physiotherapists using PROMs, approximately the half use validated instruments such as the Tampa Scale for Kinesiophobia or the Pain Catastrophizing Scale while the other half limit their evaluation to anamnesis and non-validated questionnaires. Therefore, developing effective strategies to implement and facilitate the use of psychosocial-related PROMs would enhance the evaluation during the clinical practice.

Spinal cord stimulation for low back pain

BACKGROUND

Spinal cord stimulation (SCS) is a surgical intervention used to treat persistent low back pain. SCS is thought to modulate pain by sending electrical signals via implanted electrodes into the spinal cord. The long term benefits and harms of SCS for people with low back pain are uncertain.

OBJECTIVES

To assess the effects, including benefits and harms, of SCS for people with low back pain.

SEARCH METHODS

On 10 June 2022, we searched CENTRAL, MEDLINE, Embase, and one other database for published trials. We also searched three clinical trials registers for ongoing trials.

SELECTION CRITERIA

We included all randomised controlled trials and cross-over trials comparing SCS with placebo or no treatment for low back pain. The primary comparison was SCS versus placebo, at the longest time point measured in the trials. Major outcomes were mean low back pain intensity, function, health-related quality of life, global assessment of efficacy, withdrawals due to adverse events, adverse events, and serious adverse events. Our primary time point was long-term follow-up (≥ 12 months).

DATA COLLECTION AND ANALYSIS

We used standard methodological procedures expected by Cochrane.

MAIN RESULTS

We included 13 studies with 699 participants: 55% of participants were female; mean age ranged from 47 to 59 years; and all participants had chronic low back pain with mean duration of symptoms ranging from five to 12 years. Ten cross-over trials compared SCS with placebo. Three parallel-group trials assessed the addition of SCS to medical management. Most studies were at risk of performance and detection bias from inadequate blinding and selective reporting bias. The placebo-controlled trials had other important biases, including lack of accounting for period and carryover effects. Two of the three parallel trials assessing SCS as an addition to medical management were at risk of attrition bias, and all three had substantial cross-over to the SCS group for time points beyond six months. In the parallel-group trials, we considered the lack of placebo control to be an important source of bias. None of our included studies evaluated the impact of SCS on mean low back pain intensity in the long term (≥ 12 months). The studies most often assessed outcomes in the immediate term (less than one month). At six months, the only available evidence was from a single cross-over trial (50 participants). There was moderate-certainty evidence that SCS probably does not improve back or leg pain, function, or quality of life compared with placebo. Pain was 61 points (on a 0- to 100-point scale, 0 = no pain) at six months with placebo, and 4 points better (8.2 points better to 0.2 points worse) with SCS. Function was 35.4 points (on a 0- to 100-point scale, 0 = no disability or best function) at six months with placebo, and 1.3 points better (3.9 points better to 1.3 points worse) with SCS. Health-related quality of life was 0.44 points out of 1 (0 to 1 index, 0 = worst quality of life) at six months with placebo, and 0.04 points better (0.16 points better to 0.08 points worse) with SCS. In that same study, nine participants (18%) experienced adverse events and four (8%) required revision surgery. Serious adverse events with SCS included infections, neurological damage, and lead migration requiring repeated surgery. We could not provide effect estimates of the relative risks as events were not reported for the placebo period. In parallel trials assessing SCS as an addition to medical management, it is uncertain whether, in the medium or long term, SCS can reduce low back pain, leg pain, or health-related quality of life, or if it increases the number of people reporting a 50% improvement or better, because the certainty of the evidence was very low. Low-certainty evidence suggests that adding SCS to medical management may slightly improve function and slightly reduce opioid use. In the medium term, mean function (0- to 100-point scale; lower is better) was 16.2 points better with the addition of SCS to medical management compared with medical management alone (95% confidence interval (CI) 19.4 points better to 13.0 points better; I2 = 95%; 3 studies, 430 participants; low-certainty evidence). The number of participants reporting opioid medicine use was 15% lower with the addition of SCS to medical management (95% CI 27% lower to 0% lower; I2 = 0%; 2 studies, 290 participants; low-certainty evidence). Adverse events with SCS were poorly reported but included infection and lead migration. One study found that, at 24 months, 13 of 42 people (31%) receiving SCS required revision surgery. It is uncertain to what extent the addition of SCS to medical management increases the risk of withdrawals due to adverse events, adverse events, or serious adverse events, because the certainty of the evidence was very low.

AUTHORS' CONCLUSIONS

Data in this review do not support the use of SCS to manage low back pain outside a clinical trial. Current evidence suggests SCS probably does not have sustained clinical benefits that would outweigh the costs and risks of this surgical intervention.

Assessment of exercise-induced hypoalgesia in chronic low back pain and potential associations with psychological factors and central sensitization symptoms: A case-control study

INTRODUCTION

Exercise is the most recommended treatment for chronic low back pain (CLBP) and is effective in reducing pain, but the mechanisms underlying its effects remain poorly understood. Exercise-induced hypoalgesia (EIH) may play a role and is thought to be driven by central pain modulation mechanisms. However, EIH appears to be disrupted in many chronic pain conditions and its presence in people with CLBP remains unclear. As people suffering from chronic pain often exhibit psychological factors and central sensitization symptoms influencing pain perception, EIH might be associated with these factors.

OBJECTIVE

The aim of this study is to compare the level of EIH between participants with and without CLBP following back and wrist exercises and to assess the associations between EIH, psychological factors, and symptoms of central sensitization (using the central sensitization inventory - CSI) in CLBP.

METHOD

Twenty-eight participants with CLBP and 23 without pain were recruited. Pressure pain thresholds (PPT) were measured at 4 sites (2 bony sites = capitate, S1|2 muscle sites = wrist flexors, lumbar erector spinae) before and after each of two exercises (wrist flexion and lumbar extension). Exercise-induced hypoalgesia was defined as percent change in PPT from pre- to post-exercise. Participants with CLBP also completed questionnaires to measure psychological factors (e.g., kinesiophobia, catastrophizing, anxiety, and self-efficacy) and symptoms of central sensitization (CSI), and correlations with EIH were calculated.

RESULTS

After wrist exercise, EIH measured at the muscle sites was lower in the CLBP group compared with the pain-free group (p = 0.047) but no differences were found at bony sites (p = 0.49). No significant differences for EIH were observed following back exercise at muscle sites (p = 0.14) or at bony sites (p = 0.65). Exercise-induced hypoalgesia was not correlated with any psychological factors or with the CSI score.

CONCLUSION

The lower EIH following wrist exercises may represent an alteration in pain modulation control in CLBP. However, psychological factors and central sensitization symptoms may not explain the differences observed.

Mechanisms of chiropractic spinal manipulative therapy for patients with chronic primary low back pain: protocol for a mechanistic randomised placebo-controlled trial

INTRODUCTION

Chronic low back pain (CLBP) is a highly prevalent and disabling condition. Identifying subgroups of patients afflicted with CLBP is a current research priority, for which a classification system based on pain mechanisms was proposed. Spinal manipulative therapy (SMT) is recommended for the management of CLBP. Yet, little data are available regarding its mechanisms of action, making it difficult to match this intervention to the patients who may benefit the most. It was suggested that SMT may influence mechanisms associated with central sensitisation. Therefore, classifying patients with CLBP according to central sensitisation mechanisms may help predict their response to SMT.

METHODS AND ANALYSIS

This protocol describes a randomised placebo-controlled trial aiming to examine which variables linked to central sensitisation may help predict the clinical response to SMT in a cohort of patients with CLBP. One hundred patients with chronic primary low back pain will be randomised to receive 12 sessions of SMT or placebo SMT over a 4-week period. Pain intensity and disability will be assessed as primary outcomes after completing the 4-week treatment (primary endpoint), and at 4-week and 12-week follow-ups. Baseline values of two pain questionnaires, lumbar pressure pain thresholds, concentrations of an inflammatory cytokine and expectations of pain relief will be entered as predictors of the response to SMT in a multiple regression model. Changes in these variables after treatment will be used in a second multiple regression model. The reference values of these predictors will be measured from 50 age and sex-matched healthy controls to allow interpretation of values in patients. Mixed analyses of variance will also be conducted to compare the primary outcomes and the predictors between groups (SMT vs placebo) over time (baseline vs post-treatment).

ETHICS AND DISSEMINATION

Ethical approval was granted by the Fundación Jiménez Díaz Clinical Research Ethics Committee.

TRIAL REGISTRATION NUMBER

NCT05162924.

The midline interlaminar ligament of the spine: An anatomical study

INTRODUCTION

During routine cadaveric dissection, Simonds et al. in 2019 found a previously undocumented ligament, which they termed the midline interlaminar ligament (MIL), in 24 out of 36 (76.5%) lumbar spinal levels. The MIL is an unpaired ligament located between and distinctly separate from the right and left ligamenta flava (LF). The purpose of this study was to identify the presence or absence of the MIL in the cervical, thoracic, and lumbar spinal regions and obtain detailed measurements of the ligaments' toughness (R) and elastic modulus (E).

MATERIALS AND METHODS

Intact preserved cadaveric vertebrae from C2 to the upper sacral region were dissected. Presence or absence of the MIL was documented, and length and width of each MIL were measured in situ. The R and E of the LFs from corresponding spinal segments were found for comparison.

RESULTS

At least one MIL was observed in 90.3% (28) of specimens. Eighty-eight MIL's were observed out of 186 cervical intervertebral levels (0.5%), 371 thoracic intervertebral levels (5.9%), and 101 lumbar intervertebral levels (63.4%). The mean width and length of the MIL were 1.21 ± 0.36 and 16.37 ± 2.17 mm, respectively. The mean R of the MIL and the LF were 1390.27 and 2068.04 J m^-2 , respectively. The mean E of the MILs and LFs was 46.78 ± 16.65 and 51.15 ± 21.68 MPa, respectively.

CONCLUSIONS

Based on our findings, the MIL was present in the majority of vertebrae in our cadaveric population with a predominance for the lumbar region.

Characteristics and Outcomes of Patients Receiving Physical Therapy for Low Back Pain with a Nociplastic Pain Presentation: A Secondary Analysis

Introduction

Individuals with low back pain (LBP) may be classified based on mechanistic descriptors, such as a nociplastic pain presentation (NPP). The purpose of this secondary analysis was to examine the frequency and characteristics of patients with a NPP referred to physical therapy with LBP. Additionally, we characterized patients with LBP meeting the criteria for NPP by demographic, clinical, psychological, and pain sensitivity variables. Finally, we examined short- and long-term clinical outcomes in patients with a NPP compared to those without a NPP.

Materials and Methods

Patients referred to physical therapy for LBP completed the Patient Self-report Survey for the Assessment of Fibromyalgia. Participants were categorized as "LBP with NPP" or "LBP without NPP" based on the threshold established in this measure. A rank sum test examined for differences in pain-related psychological factors and pressure-pain threshold between groups. Next, a Friedman test examined if LBP intensity and disability trajectories differed by groups at one and six months after initiation of physical therapy.

Results

22.2% of patients referred to physical therapy for LBP met the criteria for a NPP. Patients with a NPP reported significantly greater disability, pain catastrophizing, depression, anxiety, and somatization compared to individuals without a NPP (p < 0.05). Pressure-pain threshold did not differ between groups (p > 0.05). Individuals with LBP with a NPP demonstrated nonsignificant, small to medium reductions in pain and disability at one and six months. Individuals experiencing LBP without a NPP demonstrated significant reductions in pain and disability in the short- and long term.

Conclusion

Patients with LBP with a NPP displayed greater negative pain-related psychological factors but similar pain sensitivity compared to LBP without NPP.

Pain prevalence and characteristics in survivors of solid cancers: a systematic review and meta-analysis

PURPOSE

The latest systematic review on the prevalence of pain in cancer survivors was published 5 years ago. The current review aims to provide an extended overview on the prevalence of pain, pain mechanisms, pain characteristics, and assessment methods in cancer survivors.

METHODS

A systematic research was conducted on 17th of April 2020 using MEDLINE, Embase, Scopus, Web of Science, and Cochrane looking at studies from 2014 to 2020. Studies had to report pain prevalence rates in cancer survivors with a solid tumor who finished curative treatment at least 3 months ago. Methodological quality was assessed by two independent reviewers using the Joanna Briggs Institute quality appraisal tool. Characteristics of the included studies, participants and reported pain prevalence rates were extracted. The reported prevalence rates of the individual studies were pooled within a meta-analysis. Meta-regressions were performed to identify possible determinants of the pooled pain prevalence.

RESULTS

After deduplication, 7300 articles were screened, after which 38 were included in the meta-analysis. Risk of bias was rated low in 26 articles and moderate in 12 articles. The pooled pain prevalence was 47% (95%CI 39-55), with a heterogeneity of 98.99%.

CONCLUSION

This meta-analysis suggests that nearly half of cancer survivors report pain after completing curative treatment at least 3 months ago. However, substantial unexplained heterogeneity warrants cautious interpretation of these results. Meta-regression using cancer type, treatment location, pain measurement, and follow-up time as a covariate could not explain influencing factors explaining the high heterogeneity.

The two-stage therapeutic effect of posture biofeedback training on back pain and the associated mechanism: A retrospective cohort study

Introduction: Back pain is an extremely common symptom experienced by people of all ages and the number one cause of disability worldwide.² Poor posture has been identified as one of the factors leading to back pain. Digital biofeedback technology demonstrates the promising therapeutic ability in pain management through posture training. One common goal of such an approach is to increase users' posture awareness with associated movement correction. However, we lack a deep understanding of the biofeedback therapeutic mechanisms and the temporal dynamics of efficacy. Objective: This study investigates the temporal dynamics of the biofeedback learning process and associated outcomes in daily life settings, testing the mechanism of the biofeedback-associated pain reduction. Methods: This retrospective real-world evidence study followed 981 users who used the UpRight posture biofeedback platform. Piecewise mixed models were used for modeling the two-stage trajectory of pain levels, perceived posture quality, and weekly training duration following an 8-week biofeedback training. Also, the mediation effect of perceived posture quality on the analgesic effect of training duration was tested using Monte Carlo simulations based on lagged effect mixed models. Results: The analysis revealed significant pain level reduction (p <.0001) and posture quality improvement (p <.0001) during the first 4 weeks of the training, maintaining similar pain levels and perceived posture quality during the next 4 weeks. In addition, weekly training duration demonstrated an increase during the first 3 weeks (p <.001) and decreased during the next 5 weeks (p <.001). Moreover, training duration predicted following-week perceived posture quality (p <.001) and in turn perceived posture quality predicted following-week pain (p <.001) (p = 0.30). Finally, perceived posture quality mediated the effect of weekly training duration on the pain levels in 2 weeks (p <.0001). Conclusion: Our findings provide a better understanding of the therapeutic dynamic during digital biofeedback intervention targeting pain, modeling the associated two-stage process. Moreover, the study sheds light on the biofeedback mechanism and may assist in developing a better therapeutic approach targeting perceived posture quality.